WorldWideScience

Sample records for ground-based sense-and-avoid display

  1. Airborne Collision Detection and Avoidance for Small UAS Sense and Avoid Systems

    Science.gov (United States)

    Sahawneh, Laith Rasmi

    collision risk using the uncorrelated encounter model (UEM) developed by MIT Lincoln Laboratory. We evaluate the proposed approach using Monte Carlo simulations and compare the performance with linearly extrapolated collision detection logic. For the path planning and collision avoidance part, we present multiple reactive path planning algorithms. We first propose a collision avoidance algorithm based on a simulated chain that responds to a virtual force field produced by encountering intruders. The key feature of the proposed approach is to model the future motion of both the intruder and the ownship using a chain of waypoints that are equally spaced in time. This timing information is used to continuously re-plan paths that minimize the probability of collision. Second, we present an innovative collision avoidance logic using an ownship centered coordinate system. The technique builds a graph in the local-level frame and uses the Dijkstra's algorithm to find the least cost path. An advantage of this approach is that collision avoidance is inherently a local phenomenon and can be more naturally represented in the local coordinates than the global coordinates. Finally, we propose a two step path planner for ground-based SAA systems. In the first step, an initial suboptimal path is generated using A* search. In the second step, using the A* solution as an initial condition, a chain of unit masses connected by springs and dampers evolves in a simulated force field. The chain is described by a set of ordinary differential equations that is driven by virtual forces to find the steady-state equilibrium. The simulation results show that the proposed approach produces collision-free plans while minimizing the path length. To move towards a deployable system, we apply collision detection and avoidance techniques to a variety of simulation and sensor modalities including camera, radar and ADS-B along with suitable tracking schemes. Keywords: unmanned aircraft system, small UAS

  2. An Evaluation of Detect and Avoid (DAA) Displays for Unmanned Aircraft Systems: The Effect of Information Level and Display Location on Pilot Performance

    Science.gov (United States)

    Fern, Lisa; Rorie, R. Conrad; Pack, Jessica S.; Shively, R. Jay; Draper, Mark H.

    2015-01-01

    A consortium of government, industry and academia is currently working to establish minimum operational performance standards for Detect and Avoid (DAA) and Control and Communications (C2) systems in order to enable broader integration of Unmanned Aircraft Systems (UAS) into the National Airspace System (NAS). One subset of these performance standards will need to address the DAA display requirements that support an acceptable level of pilot performance. From a pilot's perspective, the DAA task is the maintenance of self separation and collision avoidance from other aircraft, utilizing the available information and controls within the Ground Control Station (GCS), including the DAA display. The pilot-in-the-loop DAA task requires the pilot to carry out three major functions: 1) detect a potential threat, 2) determine an appropriate resolution maneuver, and 3) execute that resolution maneuver via the GCS control and navigation interface(s). The purpose of the present study was to examine two main questions with respect to DAA display considerations that could impact pilots' ability to maintain well clear from other aircraft. First, what is the effect of a minimum (or basic) information display compared to an advanced information display on pilot performance? Second, what is the effect of display location on UAS pilot performance? Two levels of information level (basic, advanced) were compared across two levels of display location (standalone, integrated), for a total of four displays. The authors propose an eight-stage pilot-DAA interaction timeline from which several pilot response time metrics can be extracted. These metrics were compared across the four display conditions. The results indicate that the advanced displays had faster overall response times compared to the basic displays, however, there were no significant differences between the standalone and integrated displays. Implications of the findings on understanding pilot performance on the DAA task, the

  3. Retrieval of liquid water cloud properties from ground-based remote sensing observations

    NARCIS (Netherlands)

    Knist, C.L.

    2014-01-01

    Accurate ground-based remotely sensed microphysical and optical properties of liquid water clouds are essential references to validate satellite-observed cloud properties and to improve cloud parameterizations in weather and climate models. This requires the evaluation of algorithms for retrieval of

  4. Remote sensing of high-latitude ionization profiles by ground-based and spaceborne instrumentation

    International Nuclear Information System (INIS)

    Vondrak, R.R.

    1981-01-01

    Ionospheric specification and modeling are now largely based on data provided by active remote sensing with radiowave techniques (ionosondes, incoherent-scatter radars, and satellite beacons). More recently, passive remote sensing techniques have been developed that can be used to monitor quantitatively the spatial distribution of high-latitude E-region ionization. These passive methods depend on the measurement, or inference, of the energy distribution of precipitating kilovolt electrons, the principal source of the nighttime E-region at high latitudes. To validate these techniques, coordinated measurements of the auroral ionosphere have been made with the Chatanika incoherent-scatter radar and a variety of ground-based and spaceborne sensors

  5. MetaSensing's FastGBSAR: ground based radar for deformation monitoring

    Science.gov (United States)

    Rödelsperger, Sabine; Meta, Adriano

    2014-10-01

    The continuous monitoring of ground deformation and structural movement has become an important task in engineering. MetaSensing introduces a novel sensor system, the Fast Ground Based Synthetic Aperture Radar (FastGBSAR), based on innovative technologies that have already been successfully applied to airborne SAR applications. The FastGBSAR allows the remote sensing of deformations of a slope or infrastructure from up to a distance of 4 km. The FastGBSAR can be setup in two different configurations: in Real Aperture Radar (RAR) mode it is capable of accurately measuring displacements along a linear range profile, ideal for monitoring vibrations of structures like bridges and towers (displacement accuracy up to 0.01 mm). Modal parameters can be determined within half an hour. Alternatively, in Synthetic Aperture Radar (SAR) configuration it produces two-dimensional displacement images with an acquisition time of less than 5 seconds, ideal for monitoring areal structures like dams, landslides and open pit mines (displacement accuracy up to 0.1 mm). The MetaSensing FastGBSAR is the first ground based SAR instrument on the market able to produce two-dimensional deformation maps with this high acquisition rate. By that, deformation time series with a high temporal and spatial resolution can be generated, giving detailed information useful to determine the deformation mechanisms involved and eventually to predict an incoming failure. The system is fully portable and can be quickly installed on bedrock or a basement. The data acquisition and processing can be fully automated leading to a low effort in instrument operation and maintenance. Due to the short acquisition time of FastGBSAR, the coherence between two acquisitions is very high and the phase unwrapping is simplified enormously. This yields a high density of resolution cells with good quality and high reliability of the acquired deformations. The deformation maps can directly be used as input into an Early

  6. A ground temperature map of the North Atlantic permafrost region based on remote sensing and reanalysis data

    DEFF Research Database (Denmark)

    Westermann, S.; Østby, T. I.; Gisnås, K.

    2015-01-01

    Permafrost is a key element of the terrestrial cryosphere which makes mapping and monitoring of its state variables an imperative task. We present a modeling scheme based on remotely sensed land surface temperatures and reanalysis products from which mean annual ground temperatures (MAGT) can be ...... with gradually decreasing permafrost probabilities. The study exemplifies the unexploited potential of remotely sensed data sets in permafrost mapping if they are employed in multi-sensor multi-source data fusion approaches.......Permafrost is a key element of the terrestrial cryosphere which makes mapping and monitoring of its state variables an imperative task. We present a modeling scheme based on remotely sensed land surface temperatures and reanalysis products from which mean annual ground temperatures (MAGT) can...

  7. Review of commonly used remote sensing and ground-based ...

    African Journals Online (AJOL)

    This review provides an overview of the use of remote sensing data, the development of spectral reflectance indices for detecting plant water stress, and the usefulness of field measurements for ground-truthing purposes. Reliable measurements of plant water stress over large areas are often required for management ...

  8. Ground-based Polarization Remote Sensing of Atmospheric Aerosols and the Correlation between Polarization Degree and PM2.5

    International Nuclear Information System (INIS)

    Cheng, Chen; Zhengqiang, Li; Weizhen, Hou; Yisong, Xie; Donghui, Li; Kaitao, Li; Ying, Zhang

    2014-01-01

    The ground-based polarization remote sensing adds the polarization dimension information to traditional intensity detection, which provides a new method to detect atmospheric aerosols properties. In this paper, the polarization measurements achieved by a new multi-wavelength sun photometer, CE318-DP, are used for the ground-based remote sensing of atmospheric aerosols. In addition, a polarized vector radiative transfer model is introduced to simulate the DOLP (Degree Of Linear Polarization) under different sky conditions. At last, the correlative analysis between mass density of PM 2.5 and multi-wavelength and multi-angular DOLP is carried out. The result shows that DOLP has a high correlation with mass density of PM 2.5 , R 2 >0.85. As a consequence, this work provides a new method to estimate the mass density of PM 2.5 by using the comprehensive network of ground-based sun photometer

  9. A Comparison of Two Above-Ground Biomass Estimation Techniques Integrating Satellite-Based Remotely Sensed Data and Ground Data for Tropical and Semiarid Forests in Puerto Rico

    Science.gov (United States)

    Two above-ground forest biomass estimation techniques were evaluated for the United States Territory of Puerto Rico using predictor variables acquired from satellite based remotely sensed data and ground data from the U.S. Department of Agriculture Forest Inventory Analysis (FIA)...

  10. Classification of high resolution remote sensing image based on geo-ontology and conditional random fields

    Science.gov (United States)

    Hong, Liang

    2013-10-01

    The availability of high spatial resolution remote sensing data provides new opportunities for urban land-cover classification. More geometric details can be observed in the high resolution remote sensing image, Also Ground objects in the high resolution remote sensing image have displayed rich texture, structure, shape and hierarchical semantic characters. More landscape elements are represented by a small group of pixels. Recently years, the an object-based remote sensing analysis methodology is widely accepted and applied in high resolution remote sensing image processing. The classification method based on Geo-ontology and conditional random fields is presented in this paper. The proposed method is made up of four blocks: (1) the hierarchical ground objects semantic framework is constructed based on geoontology; (2) segmentation by mean-shift algorithm, which image objects are generated. And the mean-shift method is to get boundary preserved and spectrally homogeneous over-segmentation regions ;(3) the relations between the hierarchical ground objects semantic and over-segmentation regions are defined based on conditional random fields framework ;(4) the hierarchical classification results are obtained based on geo-ontology and conditional random fields. Finally, high-resolution remote sensed image data -GeoEye, is used to testify the performance of the presented method. And the experimental results have shown the superiority of this method to the eCognition method both on the effectively and accuracy, which implies it is suitable for the classification of high resolution remote sensing image.

  11. Efficient Imaging and Real-Time Display of Scanning Ion Conductance Microscopy Based on Block Compressive Sensing

    Science.gov (United States)

    Li, Gongxin; Li, Peng; Wang, Yuechao; Wang, Wenxue; Xi, Ning; Liu, Lianqing

    2014-07-01

    Scanning Ion Conductance Microscopy (SICM) is one kind of Scanning Probe Microscopies (SPMs), and it is widely used in imaging soft samples for many distinctive advantages. However, the scanning speed of SICM is much slower than other SPMs. Compressive sensing (CS) could improve scanning speed tremendously by breaking through the Shannon sampling theorem, but it still requires too much time in image reconstruction. Block compressive sensing can be applied to SICM imaging to further reduce the reconstruction time of sparse signals, and it has another unique application that it can achieve the function of image real-time display in SICM imaging. In this article, a new method of dividing blocks and a new matrix arithmetic operation were proposed to build the block compressive sensing model, and several experiments were carried out to verify the superiority of block compressive sensing in reducing imaging time and real-time display in SICM imaging.

  12. The workload implications of haptic displays in multi-display environments such as the cockpit: Dual-task interference of within-sense haptic inputs (tactile/proprioceptive) and between-sense inputs (tactile/proprioceptive/auditory/visual)

    OpenAIRE

    Castle, H

    2007-01-01

    Visual workload demand within the cockpit is reaching saturation, whereas the haptic sense (proprioceptive and tactile sensation) is relatively untapped, despite studies suggesting the benefits of haptic displays. MRT suggests that inputs from haptic displays will not interfere with inputs from visual or auditory displays. MRT is based on the premise that multisensory integration occurs only after unisensory processing. However, recent neuroscientific findings suggest that t...

  13. Development and use of interactive displays in real-time ground support research facilities

    Science.gov (United States)

    Rhea, Donald C.; Hammons, Kvin R.; Malone, Jacqueline C.; Nesel, Michael C.

    1989-01-01

    The NASA Western Aeronautical Test Range (WATR) is one of the world's most advanced aeronautical research flight test support facilities. A variety of advanced and often unique real-time interactive displays has been developed for use in the mission control centers (MCC) to support research flight and ground testing. These dispalys consist of applications operating on systems described as real-time interactive graphics super workstations and real-time interactive PC/AT compatible workstations. This paper reviews these two types of workstations and the specific applications operating on each display system. The applications provide examples that demonstrate overall system capability applicable for use in other ground-based real-time research/test facilities.

  14. Optical display for radar sensing

    Science.gov (United States)

    Szu, Harold; Hsu, Charles; Willey, Jefferson; Landa, Joseph; Hsieh, Minder; Larsen, Louis V.; Krzywicki, Alan T.; Tran, Binh Q.; Hoekstra, Philip; Dillard, John T.; Krapels, Keith A.; Wardlaw, Michael; Chu, Kai-Dee

    2015-05-01

    Boltzmann headstone S = kB Log W turns out to be the Rosette stone for Greek physics translation optical display of the microwave sensing hieroglyphics. The LHS is the molecular entropy S measuring the degree of uniformity scattering off the sensing cross sections. The RHS is the inverse relationship (equation) predicting the Planck radiation spectral distribution parameterized by the Kelvin temperature T. Use is made of the conservation energy law of the heat capacity of Reservoir (RV) change T Δ S = -ΔE equals to the internal energy change of black box (bb) subsystem. Moreover, an irreversible thermodynamics Δ S > 0 for collision mixing toward totally larger uniformity of heat death, asserted by Boltzmann, that derived the so-called Maxwell-Boltzmann canonical probability. Given the zero boundary condition black box, Planck solved a discrete standing wave eigenstates (equation). Together with the canonical partition function (equation) an average ensemble average of all possible internal energy yielded the celebrated Planck radiation spectral (equation) where the density of states (equation). In summary, given the multispectral sensing data (equation), we applied Lagrange Constraint Neural Network (LCNN) to solve the Blind Sources Separation (BSS) for a set of equivalent bb target temperatures. From the measurements of specific value, slopes and shapes we can fit a set of Kelvin temperatures T's for each bb targets. As a result, we could apply the analytical continuation for each entropy sources along the temperature-unique Planck spectral curves always toward the RGB color temperature display for any sensing probing frequency.

  15. Touch sensitive electrorheological fluid based tactile display

    Science.gov (United States)

    Liu, Yanju; Davidson, Rob; Taylor, Paul

    2005-12-01

    A tactile display is programmable device whose controlled surface is intended to be investigated by human touch. It has a great number of potential applications in the field of virtual reality and elsewhere. In this research, a 5 × 5 tactile display array including electrorheological (ER) fluid has been developed and investigated. Force responses of the tactile display array have been measured while a probe was moved across the upper surface. The purpose of this was to simulate the action of touch performed by human finger. Experimental results show that the sensed surface information could be controlled effectively by adjusting the voltage activation pattern imposed on the tactels. The performance of the tactile display is durable and repeatable. The touch sensitivity of this ER fluid based tactile display array has also been investigated in this research. The results show that it is possible to sense the touching force normal to the display's surface by monitoring the change of current passing through the ER fluid. These encouraging results are helpful for constructing a new type of tactile display based on ER fluid which can act as both sensor and actuator at the same time.

  16. Real-Time Hardware-in-the-Loop Laboratory Testing for Multisensor Sense and Avoid Systems

    Directory of Open Access Journals (Sweden)

    Giancarmine Fasano

    2013-01-01

    Full Text Available This paper focuses on a hardware-in-the-loop facility aimed at real-time testing of architectures and algorithms of multisensor sense and avoid systems. It was developed within a research project aimed at flight demonstration of autonomous non-cooperative collision avoidance for Unmanned Aircraft Systems. In this framework, an optionally piloted Very Light Aircraft was used as experimental platform. The flight system is based on multiple-sensor data integration and it includes a Ka-band radar, four electro-optical sensors, and two dedicated processing units. The laboratory test system was developed with the primary aim of prototype validation before multi-sensor tracking and collision avoidance flight tests. System concept, hardware/software components, and operating modes are described in the paper. The facility has been built with a modular approach including both flight hardware and simulated systems and can work on the basis of experimentally tested or synthetically generated scenarios. Indeed, hybrid operating modes are also foreseen which enable performance assessment also in the case of alternative sensing architectures and flight scenarios that are hardly reproducible during flight tests. Real-time multisensor tracking results based on flight data are reported, which demonstrate reliability of the laboratory simulation while also showing the effectiveness of radar/electro-optical fusion in a non-cooperative collision avoidance architecture.

  17. Remote sensing the plasmasphere, plasmapause, plumes and other features using ground-based magnetometers

    Directory of Open Access Journals (Sweden)

    Menk Frederick

    2014-01-01

    Full Text Available The plasmapause is a highly dynamic boundary between different magnetospheric particle populations and convection regimes. Some of the most important space weather processes involve wave-particle interactions in this region, but wave properties may also be used to remote sense the plasmasphere and plasmapause, contributing to plasmasphere models. This paper discusses the use of existing ground magnetometer arrays for such remote sensing. Using case studies we illustrate measurement of plasmapause location, shape and movement during storms; refilling of flux tubes within and outside the plasmasphere; storm-time increase in heavy ion concentration near the plasmapause; and detection and mapping of density irregularities near the plasmapause, including drainage plumes, biteouts and bulges. We also use a 2D MHD model of wave propagation through the magnetosphere, incorporating a realistic ionosphere boundary and Alfvén speed profile, to simulate ground array observations of power and cross-phase spectra, hence confirming the signatures of plumes and other density structures.

  18. Integrationof Remote Sensing and Geographic information system in Ground Water Quality Assessment and Management

    Science.gov (United States)

    Shakak, N.

    2015-04-01

    Spatial variations in ground water quality in the Khartoum state, Sudan, have been studied using geographic information system (GIS) and remote sensing technique. Gegraphical informtion system a tool which is used for storing, analyzing and displaying spatial data is also used for investigating ground water quality information. Khartoum landsat mosac image aquired in 2013was used, Arc/Gis software applied to extract the boundary of the study area, the image was classified to create land use/land cover map. The land use map,geological and soil map are used for correlation between land use , geological formations, and soil types to understand the source of natural pollution that can lower the ground water quality. For this study, the global positioning system (GPS), used in the field to identify the borehole location in a three dimentional coordinate (Latitude, longitude, and altitude), water samples were collected from 156 borehole wells, and analyzed for physico-chemical parameters like electrical conductivity, Total dissolved solid,Chloride, Nitrate, Sodium, Magnisium, Calcium,and Flouride, using standard techniques in the laboratory and compared with the standards.The ground water quality maps of the entire study area have been prepared using spatial interpolation technique for all the above parameters.then the created maps used to visualize, analyze, and understand the relationship among the measured points. Mapping was coded for potable zones, non-potable zones in the study area, in terms of water quality sutability for drinking water and sutability for irrigation. In general satellite remote sensing in conjunction with geographical information system (GIS) offers great potential for water resource development and management.

  19. A study on model fidelity for model predictive control-based obstacle avoidance in high-speed autonomous ground vehicles

    Science.gov (United States)

    Liu, Jiechao; Jayakumar, Paramsothy; Stein, Jeffrey L.; Ersal, Tulga

    2016-11-01

    This paper investigates the level of model fidelity needed in order for a model predictive control (MPC)-based obstacle avoidance algorithm to be able to safely and quickly avoid obstacles even when the vehicle is close to its dynamic limits. The context of this work is large autonomous ground vehicles that manoeuvre at high speed within unknown, unstructured, flat environments and have significant vehicle dynamics-related constraints. Five different representations of vehicle dynamics models are considered: four variations of the two degrees-of-freedom (DoF) representation as lower fidelity models and a fourteen DoF representation with combined-slip Magic Formula tyre model as a higher fidelity model. It is concluded that the two DoF representation that accounts for tyre nonlinearities and longitudinal load transfer is necessary for the MPC-based obstacle avoidance algorithm in order to operate the vehicle at its limits within an environment that includes large obstacles. For less challenging environments, however, the two DoF representation with linear tyre model and constant axle loads is sufficient.

  20. NASA UAS Integration into the NAS Project Detect and Avoid Display Evaluations

    Science.gov (United States)

    Shively, Jay

    2016-01-01

    As part of the Air Force - NASA Bi-Annual Research Council Meeting, slides will be presented on phase 1 Detect and Avoid (DAA) display evaluations. A series of iterative human-in-the-loops (HITL) experiments were conducted with different display configurations to objectively measure pilot performance on maintaining well clear. To date, four simulations and two mini-HITLs have been conducted. Data from these experiments have been incorporated into a revised alerting structure and included in the RTCA SC 228 Phase 1 Minimum Operational Performance Standards (MOPS) proposal. Plans for phase 2 are briefly discussed.

  1. Ground-Based Remote Sensing of Volcanic CO2 Fluxes at Solfatara (Italy—Direct Versus Inverse Bayesian Retrieval

    Directory of Open Access Journals (Sweden)

    Manuel Queißer

    2018-01-01

    Full Text Available CO2 is the second most abundant volatile species of degassing magma. CO2 fluxes carry information of incredible value, such as periods of volcanic unrest. Ground-based laser remote sensing is a powerful technique to measure CO2 fluxes in a spatially integrated manner, quickly and from a safe distance, but it needs accurate knowledge of the plume speed. The latter is often difficult to estimate, particularly for complex topographies. So, a supplementary or even alternative way of retrieving fluxes would be beneficial. Here, we assess Bayesian inversion as a potential technique for the case of the volcanic crater of Solfatara (Italy, a complex terrain hosting two major CO2 degassing fumarolic vents close to a steep slope. Direct integration of remotely sensed CO2 concentrations of these vents using plume speed derived from optical flow analysis yielded a flux of 717 ± 121 t day−1, in agreement with independent measurements. The flux from Bayesian inversion based on a simple Gaussian plume model was in excellent agreement under certain conditions. In conclusion, Bayesian inversion is a promising retrieval tool for CO2 fluxes, especially in situations where plume speed estimation methods fail, e.g., optical flow for transparent plumes. The results have implications beyond volcanology, including ground-based remote sensing of greenhouse gases and verification of satellite soundings.

  2. Ground-Based Correction of Remote-Sensing Spectral Imagery

    Science.gov (United States)

    Alder-Golden, Steven M.; Rochford, Peter; Matthew, Michael; Berk, Alexander

    2007-01-01

    Software has been developed for an improved method of correcting for the atmospheric optical effects (primarily, effects of aerosols and water vapor) in spectral images of the surface of the Earth acquired by airborne and spaceborne remote-sensing instruments. In this method, the variables needed for the corrections are extracted from the readings of a radiometer located on the ground in the vicinity of the scene of interest. The software includes algorithms that analyze measurement data acquired from a shadow-band radiometer. These algorithms are based on a prior radiation transport software model, called MODTRAN, that has been developed through several versions up to what are now known as MODTRAN4 and MODTRAN5 . These components have been integrated with a user-friendly Interactive Data Language (IDL) front end and an advanced version of MODTRAN4. Software tools for handling general data formats, performing a Langley-type calibration, and generating an output file of retrieved atmospheric parameters for use in another atmospheric-correction computer program known as FLAASH have also been incorporated into the present soft-ware. Concomitantly with the soft-ware described thus far, there has been developed a version of FLAASH that utilizes the retrieved atmospheric parameters to process spectral image data.

  3. Portable laser spectrometer for airborne and ground-based remote sensing of geological CO2 emissions.

    Science.gov (United States)

    Queisser, Manuel; Burton, Mike; Allan, Graham R; Chiarugi, Antonio

    2017-07-15

    A 24 kg, suitcase sized, CW laser remote sensing spectrometer (LARSS) with a ~2 km range has been developed. It has demonstrated its flexibility in measuring both atmospheric CO2 from an airborne platform and terrestrial emission of CO2 from a remote mud volcano, Bledug Kuwu, Indonesia, from a ground-based sight. This system scans the CO2 absorption line with 20 discrete wavelengths, as opposed to the typical two-wavelength online offline instrument. This multi-wavelength approach offers an effective quality control, bias control, and confidence estimate of measured CO2 concentrations via spectral fitting. The simplicity, ruggedness, and flexibility in the design allow for easy transportation and use on different platforms with a quick setup in some of the most challenging climatic conditions. While more refinement is needed, the results represent a stepping stone towards widespread use of active one-sided gas remote sensing in the earth sciences.

  4. Coupling Fine-Scale Root and Canopy Structure Using Ground-Based Remote Sensing

    Directory of Open Access Journals (Sweden)

    Brady S. Hardiman

    2017-02-01

    Full Text Available Ecosystem physical structure, defined by the quantity and spatial distribution of biomass, influences a range of ecosystem functions. Remote sensing tools permit the non-destructive characterization of canopy and root features, potentially providing opportunities to link above- and belowground structure at fine spatial resolution in functionally meaningful ways. To test this possibility, we employed ground-based portable canopy LiDAR (PCL and ground penetrating radar (GPR along co-located transects in forested sites spanning multiple stages of ecosystem development and, consequently, of structural complexity. We examined canopy and root structural data for coherence (i.e., correlation in the frequency of spatial variation at multiple spatial scales ≤10 m within each site using wavelet analysis. Forest sites varied substantially in vertical canopy and root structure, with leaf area index and root mass more becoming even vertically as forests aged. In all sites, above- and belowground structure, characterized as mean maximum canopy height and root mass, exhibited significant coherence at a scale of 3.5–4 m, and results suggest that the scale of coherence may increase with stand age. Our findings demonstrate that canopy and root structure are linked at characteristic spatial scales, which provides the basis to optimize scales of observation. Our study highlights the potential, and limitations, for fusing LiDAR and radar technologies to quantitatively couple above- and belowground ecosystem structure.

  5. Application of an ADS-B Sense and Avoid Algorithm

    Science.gov (United States)

    Arteaga, Ricardo; Kotcher, Robert; Cavalin, Moshe; Dandachy, Mohammed

    2016-01-01

    The National Aeronautics and Space Administration Armstrong Flight Research Center in Edwards, California is leading a program aimed towards integrating unmanned aircraft system into the national airspace system (UAS in the NAS). The overarching goal of the program is to reduce technical barriers associated with related safety issues as well as addressing challenges that will allow UAS routine access to the national airspace. This research paper focuses on three novel ideas: (1) A design of an integrated UAS equipped with Automatic Dependent Surveillance-Broadcast that constructs a more accurate state-based airspace model; (2) The use of Stratway Algorithm in a real-time environment; and (3) The verification and validation of sense and avoid performance and usability test results which provide a pilot's perspective on how our system will benefit the UAS in the NAS program for both piloted and unmanned aircraft.

  6. Current development of UAV sense and avoid system

    Science.gov (United States)

    Zhahir, A.; Razali, A.; Mohd Ajir, M. R.

    2016-10-01

    As unmanned aerial vehicles (UAVs) are now gaining high interests from civil and commercialised market, the automatic sense and avoid (SAA) system is currently one of the essential features in research spotlight of UAV. Several sensor types employed in current SAA research and technology of sensor fusion that offers a great opportunity in improving detection and tracking system are presented here. The purpose of this paper is to provide an overview of SAA system development in general, as well as the current challenges facing UAV researchers and designers.

  7. Aerosol optical properties over the Svalbard region of Arctic: ground-based measurements and satellite remote sensing

    Science.gov (United States)

    Gogoi, Mukunda M.; Babu, S. Suresh

    2016-05-01

    In view of the increasing anthropogenic presence and influence of aerosols in the northern polar regions, long-term continuous measurements of aerosol optical parameters have been investigated over the Svalbard region of Norwegian Arctic (Ny-Ålesund, 79°N, 12°E, 8 m ASL). This study has shown a consistent enhancement in the aerosol scattering and absorption coefficients during spring. The relative dominance of absorbing aerosols is more near the surface (lower single scattering albedo), compared to that at the higher altitude. This is indicative of the presence of local anthropogenic activities. In addition, long-range transported biomass burning aerosols (inferred from the spectral variation of absorption coefficient) also contribute significantly to the higher aerosol absorption in the Arctic spring. Aerosol optical depth (AOD) estimates from ground based Microtop sun-photometer measurements reveals that the columnar abundance of aerosols reaches the peak during spring season. Comparison of AODs between ground based and satellite remote sensing indicates that deep blue algorithm of Moderate Resolution Imaging Spectroradiometer (MODIS) retrievals over Arctic snow surfaces overestimate the columnar AOD.

  8. Using Open Access Satellite Data Alongside Ground Based Remote Sensing: An Assessment, with Case Studies from Egypt’s Delta

    Directory of Open Access Journals (Sweden)

    Sarah Parcak

    2017-09-01

    Full Text Available This paper will assess the most recently available open access high-resolution optical satellite data (0.3 m–0.6 m and its detection of buried ancient features versus ground based remote sensing tools. It also discusses the importance of CORONA satellite data to evaluate landscape changes over the past 50 years surrounding sites. The study concentrates on Egypt’s Nile Delta, which is threatened by rising sea and water tables and urbanization. Many ancient coastal sites will be lost in the next few decades, thus this paper emphasizes the need to map them before they disappear. It shows that high resolution satellites can sometimes provide the same general picture on ancient sites in the Egyptian Nile Delta as ground based remote sensing, with relatively sandier sedimentary and degrading tell environments, during periods of rainfall, and higher groundwater conditions. Research results also suggest potential solutions for rapid mapping of threatened Delta sites, and urge a collaborative global effort to maps them before they disappear.

  9. Post-attack aposematic display in prey facilitates predator avoidance learning

    Directory of Open Access Journals (Sweden)

    Changku eKang

    2016-04-01

    Full Text Available Warning signals protect unpalatable prey from predation because predators who learn the association between the warning signal and prey unprofitability decrease attacks on the prey. Most of the research have focused on visual aposematic signals that are constantly presented and visible to the predators. But a variety of chemically defended insects are rather cryptic when resting, and only in response to predator attacks (post-attack they perform displays of conspicuous abdomens or hindwings normally hidden under forewings. The function of those displays in unpalatable insects is not well understood. We examined two adaptive hypotheses on this facultative aposematic display using wild-caught oriental tits (Parus minor as predators. First, we tested whether the display increases the rejection of the prey by predators upon seeing the display (i.e. at the moment of attack through learning trials (aposematic signaling hypothesis. Second, we tested whether the display facilitates the memory formation between cryptic visible form of the prey and prey defense so that it prevents the predators initiate an attack upon seeing the cryptic form (facilitation hypothesis. We found that predators learned to avoid attacking the prey which supports the facilitation hypothesis. However, the support for the aposematic signaling hypothesis was equivocal. Our results open new directions of research by highlighting the possibility that similar facilitation effects may contribute to the evolution of various forms of post-attack visual displays in chemically, or otherwise, defended animals.

  10. Analysis of 2015 Winter In-Flight Icing Case Studies with Ground-Based Remote Sensing Systems Compared to In-Situ SLW Sondes

    Science.gov (United States)

    Serke, David J.; King, Michael Christopher; Hansen, Reid; Reehorst, Andrew L.

    2016-01-01

    National Aeronautics and Space Administration (NASA) and the National Center for Atmospheric Research (NCAR) have developed an icing remote sensing technology that has demonstrated skill at detecting and classifying icing hazards in a vertical column above an instrumented ground station. This technology has recently been extended to provide volumetric coverage surrounding an airport. Building on the existing vertical pointing system, the new method for providing volumetric coverage utilizes a vertical pointing cloud radar, a multi-frequency microwave radiometer with azimuth and elevation pointing, and a NEXRAD radar. The new terminal area icing remote sensing system processes the data streams from these instruments to derive temperature, liquid water content, and cloud droplet size for each examined point in space. These data are then combined to ultimately provide icing hazard classification along defined approach paths into an airport. To date, statistical comparisons of the vertical profiling technology have been made to Pilot Reports and Icing Forecast Products. With the extension into relatively large area coverage and the output of microphysical properties in addition to icing severity, the use of these comparators is not appropriate and a more rigorous assessment is required. NASA conducted a field campaign during the early months of 2015 to develop a database to enable the assessment of the new terminal area icing remote sensing system and further refinement of terminal area icing weather information technologies in general. In addition to the ground-based remote sensors listed earlier, in-situ icing environment measurements by weather balloons were performed to produce a comprehensive comparison database. Balloon data gathered consisted of temperature, humidity, pressure, super-cooled liquid water content, and 3-D position with time. Comparison data plots of weather balloon and remote measurements, weather balloon flight paths, bulk comparisons of

  11. Investigation of the touch sensitivity of ER fluid based tactile display

    Science.gov (United States)

    Liu, Yanju; Davidson, Rob; Taylor, Paul

    2005-05-01

    A tactile display is programmable device whose controlled surface is intended to be investigated by human touch. It has a great number of potential applications in the field of virtual reality and elsewhere. In this research, a 5x5 touch sensitive tactile display array including electrorheological (ER) fluid has been developed and investigated. Experimental results show that the sensed surface information could be controlled effectively by adjusting the voltage activation pattern imposed on the tactels. In the meantime, it is possible to sense the touching force normal to the display"s surface by monitoring the change of current passing through the ER fluid. These encouraging results are helpful for constructing a new type of tactile display based on ER fluid which can act as both sensor and actuator at the same time.

  12. Application of Distributed Optical Fiber Sensing Technique in Monitoring the Ground Deformation

    Directory of Open Access Journals (Sweden)

    Jin Liu

    2017-01-01

    Full Text Available The monitoring of ground deformation is important for the prevention and control of geological disaster including land subsidence, ground fissure, surface collapse, and landslides. In this study, a distributed optical fiber sensing technique based on Brillouin Optical Time-Domain Analysis (BOTDA was used to monitor the ground deformation. The principle behind the BOTDA is first introduced, and then laboratory calibration test and physical model test were carried out. Finally, BOTDA-based monitoring of ground fissure was carried out in a test site. Experimental results show that the distributed optical fiber can measure the soil strain during ground deformation process, and the strain curve responded to the soil compression and tension region clearly. During field test in Wuxi City, China, the ground fissures deformation area was monitored accurately and the trend of deformation can also be achieved to forecast and warn against the ground fissure hazards.

  13. Small UAV Automatic Ground Collision Avoidance System Design Considerations and Flight Test Results

    Science.gov (United States)

    Sorokowski, Paul; Skoog, Mark; Burrows, Scott; Thomas, SaraKatie

    2015-01-01

    The National Aeronautics and Space Administration (NASA) Armstrong Flight Research Center Small Unmanned Aerial Vehicle (SUAV) Automatic Ground Collision Avoidance System (Auto GCAS) project demonstrated several important collision avoidance technologies. First, the SUAV Auto GCAS design included capabilities to take advantage of terrain avoidance maneuvers flying turns to either side as well as straight over terrain. Second, the design also included innovative digital elevation model (DEM) scanning methods. The combination of multi-trajectory options and new scanning methods demonstrated the ability to reduce the nuisance potential of the SUAV while maintaining robust terrain avoidance. Third, the Auto GCAS algorithms were hosted on the processor inside a smartphone, providing a lightweight hardware configuration for use in either the ground control station or on board the test aircraft. Finally, compression of DEM data for the entire Earth and successful hosting of that data on the smartphone was demonstrated. The SUAV Auto GCAS project demonstrated that together these methods and technologies have the potential to dramatically reduce the number of controlled flight into terrain mishaps across a wide range of aviation platforms with similar capabilities including UAVs, general aviation aircraft, helicopters, and model aircraft.

  14. Ground-based remote sensing of tropospheric water vapour isotopologues within the project MUSICA

    Directory of Open Access Journals (Sweden)

    M. Schneider

    2012-12-01

    Full Text Available Within the project MUSICA (MUlti-platform remote Sensing of Isotopologues for investigating the Cycle of Atmospheric water, long-term tropospheric water vapour isotopologue data records are provided for ten globally distributed ground-based mid-infrared remote sensing stations of the NDACC (Network for the Detection of Atmospheric Composition Change. We present a new method allowing for an extensive and straightforward characterisation of the complex nature of such isotopologue remote sensing datasets. We demonstrate that the MUSICA humidity profiles are representative for most of the troposphere with a vertical resolution ranging from about 2 km (in the lower troposphere to 8 km (in the upper troposphere and with an estimated precision of better than 10%. We find that the sensitivity with respect to the isotopologue composition is limited to the lower and middle troposphere, whereby we estimate a precision of about 30‰ for the ratio between the two isotopologues HD16O and H216O. The measurement noise, the applied atmospheric temperature profiles, the uncertainty in the spectral baseline, and the cross-dependence on humidity are the leading error sources. We introduce an a posteriori correction method of the cross-dependence on humidity, and we recommend applying it to isotopologue ratio remote sensing datasets in general. In addition, we present mid-infrared CO2 retrievals and use them for demonstrating the MUSICA network-wide data consistency. In order to indicate the potential of long-term isotopologue remote sensing data if provided with a well-documented quality, we present a climatology and compare it to simulations of an isotope incorporated AGCM (Atmospheric General Circulation Model. We identify differences in the multi-year mean and seasonal cycles that significantly exceed the estimated errors, thereby indicating deficits in the modeled atmospheric water cycle.

  15. Ground-based remote sensing of tropospheric water vapour isotopologues within the project MUSICA

    Science.gov (United States)

    Schneider, M.; Barthlott, S.; Hase, F.; González, Y.; Yoshimura, K.; García, O. E.; Sepúlveda, E.; Gomez-Pelaez, A.; Gisi, M.; Kohlhepp, R.; Dohe, S.; Blumenstock, T.; Wiegele, A.; Christner, E.; Strong, K.; Weaver, D.; Palm, M.; Deutscher, N. M.; Warneke, T.; Notholt, J.; Lejeune, B.; Demoulin, P.; Jones, N.; Griffith, D. W. T.; Smale, D.; Robinson, J.

    2012-12-01

    Within the project MUSICA (MUlti-platform remote Sensing of Isotopologues for investigating the Cycle of Atmospheric water), long-term tropospheric water vapour isotopologue data records are provided for ten globally distributed ground-based mid-infrared remote sensing stations of the NDACC (Network for the Detection of Atmospheric Composition Change). We present a new method allowing for an extensive and straightforward characterisation of the complex nature of such isotopologue remote sensing datasets. We demonstrate that the MUSICA humidity profiles are representative for most of the troposphere with a vertical resolution ranging from about 2 km (in the lower troposphere) to 8 km (in the upper troposphere) and with an estimated precision of better than 10%. We find that the sensitivity with respect to the isotopologue composition is limited to the lower and middle troposphere, whereby we estimate a precision of about 30‰ for the ratio between the two isotopologues HD16O and H216O. The measurement noise, the applied atmospheric temperature profiles, the uncertainty in the spectral baseline, and the cross-dependence on humidity are the leading error sources. We introduce an a posteriori correction method of the cross-dependence on humidity, and we recommend applying it to isotopologue ratio remote sensing datasets in general. In addition, we present mid-infrared CO2 retrievals and use them for demonstrating the MUSICA network-wide data consistency. In order to indicate the potential of long-term isotopologue remote sensing data if provided with a well-documented quality, we present a climatology and compare it to simulations of an isotope incorporated AGCM (Atmospheric General Circulation Model). We identify differences in the multi-year mean and seasonal cycles that significantly exceed the estimated errors, thereby indicating deficits in the modeled atmospheric water cycle.

  16. An Investigation of Alerting and Prioritization Criteria for Sense and Avoid (SAA)

    Science.gov (United States)

    2013-10-01

    TECHNICAL REPORT RDMR-TM-13-01 AN INVESTIGATION OF ALERTING AND PRIORITIZATION CRITERIA FOR SENSE AND AVOID ( SAA ...OFFICIAL ENDORSEMENT OR APPROVAL OF THE USE OF SUCH COMMERCIAL HARDWARE OR SOFTWARE . i/ii (Blank) REPORT DOCUMENTATION PAGE Form Approved...burden to Washington Headquarters Services , Directorate for Information Operations and Reports, 1215 Jefferson Davis Highway, Suite 1204, Arlington

  17. Wake Vortex Avoidance System and Method

    Science.gov (United States)

    Shams, Qamar A. (Inventor); Zuckerwar, Allan J. (Inventor); Knight, Howard K. (Inventor)

    2017-01-01

    A wake vortex avoidance system includes a microphone array configured to detect low frequency sounds. A signal processor determines a geometric mean coherence based on the detected low frequency sounds. A display displays wake vortices based on the determined geometric mean coherence.

  18. Estimating cotton canopy ground cover from remotely sensed scene reflectance

    International Nuclear Information System (INIS)

    Maas, S.J.

    1998-01-01

    Many agricultural applications require spatially distributed information on growth-related crop characteristics that could be supplied through aircraft or satellite remote sensing. A study was conducted to develop and test a methodology for estimating plant canopy ground cover for cotton (Gossypium hirsutum L.) from scene reflectance. Previous studies indicated that a relatively simple relationship between ground cover and scene reflectance could be developed based on linear mixture modeling. Theoretical analysis indicated that the effects of shadows in the scene could be compensated for by averaging the results obtained using scene reflectance in the red and near-infrared wavelengths. The methodology was tested using field data collected over several years from cotton test plots in Texas and California. Results of the study appear to verify the utility of this approach. Since the methodology relies on information that can be obtained solely through remote sensing, it would be particularly useful in applications where other field information, such as plant size, row spacing, and row orientation, is unavailable

  19. Familiar shapes attract attention in figure-ground displays.

    Science.gov (United States)

    Nelson, Rolf A; Palmer, Stephen E

    2007-04-01

    We report five experiments that explore the effect of figure-ground factors on attention. We hypothesized that figural cues, such as familiar shape, would draw attention to the figural side in an attentional cuing task using bipartite figure-ground displays. The first two experiments used faces in profile as the familiar shape and found a perceptual advantage for targets presented on the meaningful side of the central contour in detection speed (Experiment 1) and discrimination accuracy (Experiment 2). The third experiment demonstrated the figural advantage in response time (RT) with nine other familiar shapes (including a sea horse, a guitar, a fir tree, etc.), but only when targets appeared in close proximity to the contour. A fourth experiment obtained a figural advantage in a discrimination task with the larger set of familiar shapes. The final experiment ruled out eye movements as a possible confounding factor by replicating the RT advantage for targets on the figural side of face displays when all trials containing eye movements were eliminated. The results are discussed in terms of ecological influences on attention, and are cast within the framework of Yantis and Jonides's hypothesis that attention is exogenously drawn to the onset of new perceptual objects. We argue that the figural side constitutes an "object" whereas the ground side does not, and that figural cues such as shape familiarity are effective in determining which areas represent objects.

  20. Intercomparison of Remotely Sensed Vegetation Indices, Ground Spectroscopy, and Foliar Chemistry Data from NEON

    Science.gov (United States)

    Hulslander, D.; Warren, J. N.; Weintraub, S. R.

    2017-12-01

    Hyperspectral imaging systems can be used to produce spectral reflectance curves giving rich information about composition, relative abundances of materials, mixes and combinations. Indices based on just a few spectral bands have been used for over 40 years to study vegetation health, mineral abundance, and more. These indices are much simpler to visualize and use than a full hyperspectral data set which may contain over 400 bands. Yet historically, it has been difficult to directly relate remotely sensed spectral indices to quantitative biophysical properties significant to forest ecology such as canopy nitrogen, lignin, and chlorophyll. This linkage is a critical piece in enabling the detection of high value ecological information, usually only available from labor-intensive canopy foliar chemistry sampling, to the geographic and temporal coverage available via remote sensing. Previous studies have shown some promising results linking ground-based data and remotely sensed indices, but are consistently limited in time, geographic extent, and land cover type. Moreover, previous studies are often focused on tuning linkage algorithms for the purpose of achieving good results for only one study site or one type of vegetation, precluding development of more generalized algorithms. The National Ecological Observatory Network (NEON) is a unique system of 47 terrestrial sites covering all of the major eco-climatic domains of the US, including AK, HI, and Puerto Rico. These sites are regularly monitored and sampled using uniform instrumentation and protocols, including both foliar chemistry sampling and remote sensing flights for high resolution hyperspectral, LiDAR, and digital camera data acquisition. In this study we compare the results of foliar chemistry analysis to the remote sensing vegetation indices and investigate possible sources for variance and difference through the use of the larger hyperspectral dataset as well as ground based spectrometer measurements of

  1. Confronting remote sensing product with ground base measurements across time and scale

    Science.gov (United States)

    Pourmokhtarian, A.; Dietze, M.

    2015-12-01

    Ecosystem models are essential tools in forecasting ecosystem responses to global climate change. One of the most challenging issues in ecosystem modeling is scaling while preserving landscape characteristics and minimizing loss of information, when moving from point observation to regional scale. There is a keen interest in providing accurate inputs for ecosystem models which represent ecosystem initial state conditions. Remote sensing land cover products, such as Landsat NLCD and MODIS MCD12Q1, provide extensive spatio-temporal coverage but do not capture forest composition and structure. Lidar and hyperspectral have the potential to meet this need but lack sufficient spatial and historical coverage. Forest inventory measurements provide detailed information on the landscape but in a very small footprint. Combining inventory and land cover could improve estimates of ecosystem state and characteristic across time and space. This study focuses on the challenges associated with fusing and scaling the US Forest Service FIA database and NLCD across regional scales to quantify ecosystem characteristics and reduce associated uncertainties. Across Southeast of U.S. 400 stratified random samples of 10x10 km2 landscapes were selected. Data on plant density, species, age, and DBH of trees in FIA plots within each site were extracted. Using allometry equations, the canopy cover of different plant functional types (PFTs) was estimated using a PPA-style canopy model and used to assign each inventory plot to a land cover class. Inventory and land cover were fused in a Bayesian model that adjusts the fractional coverage of inventory plots while accounting for multiple sources of uncertainty. Results were compared to estimates derived from inventory alone, land cover alone, and model spin-up alone. Our findings create a framework of data assimilation to better interpret remote sensing data using ground-based measurements.

  2. Integration of Remote Sensing Products with Ground-Based Measurements to Understand the Dynamics of Nepal's Forests and Plantation Sites

    Science.gov (United States)

    Gilani, H.; Jain, A. K.

    2016-12-01

    This study assembles information from three sources - remote sensing, terrestrial photography and ground-based inventory data, to understand the dynamics of Nepal's tropical and sub-tropical forests and plantation sites for the period 1990-2015. Our study focuses on following three specific district areas, which have conserved forests through social and agroforestry management practices: 1. Dolakha district: This site has been selected to study the impact of community-based forest management on land cover change using repeat photography and satellite imagery, in combination with interviews with community members. The study time period is during the period 1990-2010. We determined that satellite data with ground photographs can provide transparency for long term monitoring. The initial results also suggests that community-based forest management program in the mid-hills of Nepal was successful. 2. Chitwan district: Here we use high resolution remote sensing data and optimized community field inventories to evaluate potential application and operational feasibility of community level REDD+ measuring, reporting and verification (MRV) systems. The study uses temporal dynamics of land cover transitions, tree canopy size classes and biomass over a Kayar khola watershed REDD+ study area with community forest to evaluate satellite Image segmentation for land cover, linear regression model for above ground biomass (AGB), and estimation and monitoring field data for tree crowns and AGB. We study three specific years 2002, 2009, 2012. Using integration of WorldView-2 and airborne LiDAR data for tree species level. 3. Nuwakot district: This district was selected to study the impact of establishment of tree plantation on total barren/fallow. Over the last 40 year, this area has went through a drastic changes, from barren land to forest area with tree species consisting of Dalbergia sissoo, Leucaena leucocephala, Michelia champaca, etc. In 1994, this district area was registered

  3. Ground-based grasslands data to support remote sensing and ecosystem modeling of terrestrial primary production

    Science.gov (United States)

    Olson, R. J.; Scurlock, J. M. O.; Turner, R. S.; Jennings, S. V.

    1995-01-01

    Estimating terrestrial net primary production (NPP) using remote-sensing tools and ecosystem models requires adequate ground-based measurements for calibration, parameterization, and validation. These data needs were strongly endorsed at a recent meeting of ecosystem modelers organized by the International Geosphere-Biosphere Program's (IGBP's) Data and Information System (DIS) and its Global Analysis, Interpretation, and Modelling (GAIM) Task Force. To meet these needs, a multinational, multiagency project is being coordinated by the IGBP DIS to compile existing NPP data from field sites and to regionalize NPP point estimates to various-sized grid cells. Progress at Oak Ridge National Laboratory (ORNL) on compiling NPP data for grasslands as part of the IGBP DIS data initiative is described. Site data and associated documentation from diverse field studies are being acquired for selected grasslands and are being reviewed for completeness, consistency, and adequacy of documentation, including a description of sampling methods. Data are being compiled in a database with spatial, temporal, and thematic characteristics relevant to remote sensing and global modeling. NPP data are available from the ORNL Distributed Active Archive Center (DAAC) for biogeochemical dynamics. The ORNL DAAC is part of the Earth Observing System Data and Information System, of the US National Aeronautics and Space Administration.

  4. Ground-based grasslands data to support remote sensing and ecosystem modeling of terrestrial primary production

    Energy Technology Data Exchange (ETDEWEB)

    Olson, R.J.; Turner, R.S. [Oak Ridge National Lab., TN (United States); Scurlock, J.M.O. [King`s College London, (England); Jennings, S.V. [Tennessee Univ., Knoxville, TN (United States)

    1995-12-31

    Estimating terrestrial net primary production (NPP) using remote- sensing tools and ecosystem models requires adequate ground-based measurements for calibration, parameterization, and validation. These data needs were strongly endorsed at a recent meeting of ecosystem modelers organized by the International Geosphere-Biosphere Programme`s (IGBP`s) Data and Information System (DIS) and its Global Analysis, Interpretation, and Modelling (GAIM) Task Force. To meet these needs, a multinational, multiagency project is being coordinated by the IGBP DIS to compile existing NPP data from field sites and to regionalize NPP point estimates to various-sized grid cells. Progress at Oak Ridge National Laboratory (ORNL) on compiling NPP data for grasslands as part of the IGBP DIS data initiative is described. Site data and associated documentation from diverse field studies are being acquired for selected grasslands and are being reviewed for completeness, consistency, and adequacy of documentation, including a description of sampling methods. Data are being compiled in a database with spatial, temporal, and thematic characteristics relevant to remote sensing and global modeling. NPP data are available from the ORNL Distributed Active Archive Center (DAAC) for biogeochemical dynamics. The ORNL DAAC is part of the Earth Observing System Data and Information System, of the US National Aeronautics and Space Administration.

  5. Optimal Recovery Trajectories for Automatic Ground Collision Avoidance Systems (Auto GCAS)

    Science.gov (United States)

    Suplisson, Angela W.

    The US Air Force recently fielded the F-16 Automatic Ground Collision Avoidance System (Auto GCAS). This system meets the operational requirements of being both aggressive and timely, meaning that extremely agile avoidance maneuvers will be executed at the last second to avoid the ground. This small window of automatic operation maneuvering in close proximity to the ground makes the problem challenging. There currently exists no similar Auto GCAS for manned military 'heavy' aircraft with lower climb performance such as transport, tanker, or bomber aircraft. The F-16 Auto GCAS recovery is a single pre-planned roll to wings-level and 5-g pull-up which is very effective for fighters due to their high g and climb performance, but it is not suitable for military heavy aircraft. This research proposes a new optimal control approach to the ground collision avoidance problem for heavy aircraft by mapping the aggressive and timely requirements of the automatic recovery to the optimal control formulation which includes lateral maneuvers around terrain. This novel mapping creates two ways to pose the optimal control problem for Auto GCAS; one as a Max Distance with a Timely Trigger formulation and the other as a Min Control with an Aggressive Trigger formulation. Further, the optimal path and optimal control admitted by these two formulations are demonstrated to be equivalent at the point the automatic recovery is initiated for the simplified 2-D case. The Min Control formulation was demonstrated to have faster computational speed and was chosen for the 3-D case. Results are presented for representative heavy aircraft scenarios against 3-D digital terrain. The Min Control formulation was then compared to a Multi-Trajectory Auto GCAS with five pre-planned maneuvers. Metrics were developed to quantify the improvement from using an optimal approach versus the pre-planned maneuvers. The proposed optimal Min Control method was demonstrated to require less control or trigger later

  6. Flight Deck Weather Avoidance Decision Support: Implementation and Evaluation

    Science.gov (United States)

    Wu, Shu-Chieh; Luna, Rocio; Johnson, Walter W.

    2013-01-01

    Weather related disruptions account for seventy percent of the delays in the National Airspace System (NAS). A key component in the weather plan of the Next Generation of Air Transportation System (NextGen) is to assimilate observed weather information and probabilistic forecasts into the decision process of flight crews and air traffic controllers. In this research we explore supporting flight crew weather decision making through the development of a flight deck predicted weather display system that utilizes weather predictions generated by ground-based radar. This system integrates and presents this weather information, together with in-flight trajectory modification tools, within a cockpit display of traffic information (CDTI) prototype. that the CDTI features 2D and perspective 3D visualization models of weather. The weather forecast products that we implemented were the Corridor Integrated Weather System (CIWS) and the Convective Weather Avoidance Model (CWAM), both developed by MIT Lincoln Lab. We evaluated the use of CIWS and CWAM for flight deck weather avoidance in two part-task experiments. Experiment 1 compared pilots' en route weather avoidance performance in four weather information conditions that differed in the type and amount of predicted forecast (CIWS current weather only, CIWS current and historical weather, CIWS current and forecast weather, CIWS current and forecast weather and CWAM predictions). Experiment 2 compared the use of perspective 3D and 21/2D presentations of weather for flight deck weather avoidance. Results showed that pilots could take advantage of longer range predicted weather forecasts in performing en route weather avoidance but more research will be needed to determine what combinations of information are optimal and how best to present them.

  7. Biomass burning aerosols characterization from ground based and profiling measurements

    Science.gov (United States)

    Marin, Cristina; Vasilescu, Jeni; Marmureanu, Luminita; Ene, Dragos; Preda, Liliana; Mihailescu, Mona

    2018-04-01

    The study goal is to assess the chemical and optical properties of aerosols present in the lofted layers and at the ground. The biomass burning aerosols were evaluated in low level layers from multi-wavelength lidar measurements, while chemical composition at ground was assessed using an Aerosol Chemical Speciation Monitor (ACSM) and an Aethalometer. Classification of aerosol type and specific organic markers were used to explore the potential to sense the particles from the same origin at ground base and on profiles.

  8. Supporting a Diverse Community of Undergraduate Researchers in Satellite and Ground-Based Remote Sensing

    Science.gov (United States)

    Blake, R.; Liou-Mark, J.

    2012-12-01

    The U.S. remains in grave danger of losing its global competitive edge in STEM. To find solutions to this problem, the Obama Administration proposed two new national initiatives: the Educate to Innovate Initiative and the $100 million government/private industry initiative to train 100,000 STEM teachers and graduate 1 million additional STEM students over the next decade. To assist in ameliorating the national STEM plight, the New York City College of Technology has designed its NSF Research Experience for Undergraduate (REU) program in satellite and ground-based remote sensing to target underrepresented minority students. Since the inception of the program in 2008, a total of 45 undergraduate students of which 38 (84%) are considered underrepresented minorities in STEM have finished or are continuing with their research or are pursuing their STEM endeavors. The program is comprised of the three primary components. The first component, Structured Learning Environments: Preparation and Mentorship, provides the REU Scholars with the skill sets necessary for proficiency in satellite and ground-based remote sensing research. The students are offered mini-courses in Geographic Information Systems, MATLAB, and Remote Sensing. They also participate in workshops on the Ethics of Research. Each REU student is a member of a team that consists of faculty mentors, post doctorate/graduate students, and high school students. The second component, Student Support and Safety Nets, provides undergraduates a learning environment that supports them in becoming successful researchers. Special networking and Brown Bag sessions, and an annual picnic with research scientists are organized so that REU Scholars are provided with opportunities to expand their professional community. Graduate school support is provided by offering free Graduate Record Examination preparation courses and workshops on the graduate school application process. Additionally, students are supported by college

  9. Evaluating statistical cloud schemes: What can we gain from ground-based remote sensing?

    Science.gov (United States)

    Grützun, V.; Quaas, J.; Morcrette, C. J.; Ament, F.

    2013-09-01

    Statistical cloud schemes with prognostic probability distribution functions have become more important in atmospheric modeling, especially since they are in principle scale adaptive and capture cloud physics in more detail. While in theory the schemes have a great potential, their accuracy is still questionable. High-resolution three-dimensional observational data of water vapor and cloud water, which could be used for testing them, are missing. We explore the potential of ground-based remote sensing such as lidar, microwave, and radar to evaluate prognostic distribution moments using the "perfect model approach." This means that we employ a high-resolution weather model as virtual reality and retrieve full three-dimensional atmospheric quantities and virtual ground-based observations. We then use statistics from the virtual observation to validate the modeled 3-D statistics. Since the data are entirely consistent, any discrepancy occurring is due to the method. Focusing on total water mixing ratio, we find that the mean ratio can be evaluated decently but that it strongly depends on the meteorological conditions as to whether the variance and skewness are reliable. Using some simple schematic description of different synoptic conditions, we show how statistics obtained from point or line measurements can be poor at representing the full three-dimensional distribution of water in the atmosphere. We argue that a careful analysis of measurement data and detailed knowledge of the meteorological situation is necessary to judge whether we can use the data for an evaluation of higher moments of the humidity distribution used by a statistical cloud scheme.

  10. [Sense of guilt in sexually abused children : Mediating role of avoidance coping on anxiety and self-esteem].

    Science.gov (United States)

    Gauthier-Duchesne, Amélie; Hébert, Martine; Daspe, Marie-Ève

    2017-01-01

    Prior studies have suggested self-blame and sense of guilt as important elements associated with the effects of childhood sexual abuse on adult survivors (Cantón-Cortés, Cantón, Justicia & Cortés, 2011). However, few studies have explored the potential impact of the sense of guilt on outcomes in child victims. This study examines the mediating role of avoidance coping on the relationship between sense of guilt and outcomes (anxiety and self-esteem) in sexually abused children. The sample consisted of 447 sexually abused children (319 girls and 128 boys) aged 6 to 12. Path analysis indicated that children with higher feelings of guilt about the abuse showed more anxiety and lower levels of self-esteem. Indirect effects also indicated that sense of guilt predicted avoidance coping, which in turn contributed to higher anxiety and lower self-esteem. This model, which fits the data well for both girls and boys, explains 24.4 % of the variance in anxiety and 11.2 % of the variance in self-esteem. Results suggest that sense of guilt is an important target for clinical intervention with sexually abused children.

  11. Blowing snow detection in Antarctica, from space borne and ground-based remote sensing

    Science.gov (United States)

    Gossart, A.; Souverijns, N.; Lhermitte, S.; Lenaerts, J.; Gorodetskaya, I.; Schween, J. H.; Van Lipzig, N. P. M.

    2017-12-01

    Surface mass balance (SMB) strongly controls spatial and temporal variations in the Antarctic Ice Sheet (AIS) mass balance and its contribution to sea level rise. Currently, the scarcity of observational data and the challenges of climate modelling over the ice sheet limit our understanding of the processes controlling AIS SMB. Particularly, the impact of blowing snow on local SMB is not yet constrained and is subject to large uncertainties. To assess the impact of blowing snow on local SMB, we investigate the attenuated backscatter profiles from ceilometers at two East Antarctic locations in Dronning Maud Land. Ceilometers are robust ground-based remote sensing instruments that yield information on cloud base height and vertical structure, but also provide information on the particles present in the boundary layer. We developed a new algorithm to detect blowing snow (snow particles lifted by the wind from the surface to substantial height) from the ceilometer attenuated backscatter. The algorithm successfully allows to detect strong blowing snow signal from layers thicker than 15 m at the Princess Elisabeth (PE, (72°S, 23°E)) and Neumayer (70°S, 8° W) stations. Applying the algorithm to PE, we retrieve the frequency and annual cycle of blowing snow as well as discriminate between clear sky and overcast conditions during blowing snow. We further apply the blowing snow algorithm at PE to evaluate the blowing snow events detection by satellite imagery (Palm et al., 2011): the near-surface blowing snow layers are apparent in lidar backscatter profiles and enable snowdrift events detection (spatial and temporal frequency, height and optical depth). These data are processed from CALIPSO, at a high resolution (1x1 km digital elevation model). However, the remote sensing detection of blowing snow events by satellite is limited to layers of a minimal thickness of 20-30 m. In addition, thick clouds, mostly occurring during winter storms, can impede drifting snow

  12. A soft robot capable of 2D mobility and self-sensing for obstacle detection and avoidance

    Science.gov (United States)

    Qin, Lei; Tang, Yucheng; Gupta, Ujjaval; Zhu, Jian

    2018-04-01

    Soft robots have shown great potential for surveillance applications due to their interesting attributes including inherent flexibility, extreme adaptability, and excellent ability to move in confined spaces. High mobility combined with the sensing systems that can detect obstacles plays a significant role in performing surveillance tasks. Extensive studies have been conducted on movement mechanisms of traditional hard-bodied robots to increase their mobility. However, there are limited efforts in the literature to explore the mobility of soft robots. In addition, little attempt has been made to study the obstacle-detection capability of a soft mobile robot. In this paper, we develop a soft mobile robot capable of high mobility and self-sensing for obstacle detection and avoidance. This robot, consisting of a dielectric elastomer actuator as the robot body and four electroadhesion actuators as the robot feet, can generate 2D mobility, i.e. translations and turning in a 2D plane, by programming the actuation sequence of the robot body and feet. Furthermore, we develop a self-sensing method which models the robot body as a deformable capacitor. By measuring the real-time capacitance of the robot body, the robot can detect an obstacle when the peak capacitance drops suddenly. This sensing method utilizes the robot body itself instead of external sensors to achieve detection of obstacles, which greatly reduces the weight and complexity of the robot system. The 2D mobility and self-sensing capability ensure the success of obstacle detection and avoidance, which paves the way for the development of lightweight and intelligent soft mobile robots.

  13. [Micron]ADS-B Detect and Avoid Flight Tests on Phantom 4 Unmanned Aircraft System

    Science.gov (United States)

    Arteaga, Ricardo; Dandachy, Mike; Truong, Hong; Aruljothi, Arun; Vedantam, Mihir; Epperson, Kraettli; McCartney, Reed

    2018-01-01

    were conducted at Edwards Air Force Base. Researchers in the ground control station looking at displays were able to verify the Automatic Dependent Surveillance-Broadcast target detection and collision avoidance resolutions.

  14. Java Architecture for Detect and Avoid Extensibility and Modeling

    Science.gov (United States)

    Santiago, Confesor; Mueller, Eric Richard; Johnson, Marcus A.; Abramson, Michael; Snow, James William

    2015-01-01

    Unmanned aircraft will equip with a detect-and-avoid (DAA) system that enables them to comply with the requirement to "see and avoid" other aircraft, an important layer in the overall set of procedural, strategic and tactical separation methods designed to prevent mid-air collisions. This paper describes a capability called Java Architecture for Detect and Avoid Extensibility and Modeling (JADEM), developed to prototype and help evaluate various DAA technological requirements by providing a flexible and extensible software platform that models all major detect-and-avoid functions. Figure 1 illustrates JADEM's architecture. The surveillance module can be actual equipment on the unmanned aircraft or simulators that model the process by which sensors on-board detect other aircraft and provide track data to the traffic display. The track evaluation function evaluates each detected aircraft and decides whether to provide an alert to the pilot and its severity. Guidance is a combination of intruder track information, alerting, and avoidance/advisory algorithms behind the tools shown on the traffic display to aid the pilot in determining a maneuver to avoid a loss of well clear. All these functions are designed with a common interface and configurable implementation, which is critical in exploring DAA requirements. To date, JADEM has been utilized in three computer simulations of the National Airspace System, three pilot-in-the-loop experiments using a total of 37 professional UAS pilots, and two flight tests using NASA's Predator-B unmanned aircraft, named Ikhana. The data collected has directly informed the quantitative separation standard for "well clear", safety case, requirements development, and the operational environment for the DAA minimum operational performance standards. This work was performed by the Separation Assurance/Sense and Avoid Interoperability team under NASA's UAS Integration in the NAS project.

  15. Shape Recognition Inputs to Figure-Ground Organization in Three-Dimensional Displays.

    Science.gov (United States)

    Peterson, Mary A.; Gibson, Bradley S.

    1993-01-01

    Three experiments with 29 college students and 8 members of a university community demonstrate that shape recognition processes influence perceived figure-ground relationships in 3-dimensional displays when the edge between 2 potential figural regions is both a luminance contrast edge and a disparity edge. Implications for shape recognition and…

  16. Ground-based SMART-COMMIT Measurements for Studying Aerosol and Cloud Properties

    Science.gov (United States)

    Tsay, Si-Chee

    2008-01-01

    From radiometric principles, it is expected that the retrieved properties of extensive aerosols and clouds from reflected/emitted measurements by satellite (and/or aircraft) should be consistent with those retrieved from transmitted/emitted radiance observed at the surface. Although space-borne remote sensing observations cover large spatial domain, they are often plagued by contamination of surface signatures. Thus, ground-based in-situ and remote-sensing measurements, where signals come directly from atmospheric constituents, the sun, and/or the Earth-atmosphere interactions, provide additional information content for comparisons that confirm quantitatively the usefulness of the integrated surface, aircraft, and satellite data sets. The development and deployment of SMARTCOMMIT (Surface-sensing Measurements for Atmospheric Radiative Transfer - Chemical, Optical & Microphysical Measurements of In-situ Troposphere) mobile facilities are aimed for the optimal utilization of collocated ground-based observations as constraints to yield higher fidelity satellite retrievals and to determine any sampling bias due to target conditions. To quantify the energetics of the surface-atmosphere system and the atmospheric processes, SMART-COMMIT instruments fall into three categories: flux radiometer, radiance sensor and in-situ probe. In this paper, we will demonstrate the capability of SMART-COMMIT in recent field campaigns (e.g., CRYSTAL-FACE, UAE 2, BASEASIA, NAMMA) that were designed and executed to study the compelling variability in temporal scale of both anthropogenic and natural aerosols (e.g., biomass-burning smoke, airborne dust) and cirrus clouds. We envision robust approaches in which well-collocated ground-based measurements and space-borne observations will greatly advance our knowledge of extensive aerosols and clouds.

  17. Obstacle avoidance test using a sensor-based autonomous robotic system

    International Nuclear Information System (INIS)

    Fujii, Yoshio; Suzuki, Katsuo

    1998-12-01

    From a viewpoint of reducing personnel radiation exposure of plant staffs working in the high radiation area of nuclear facilities, it is often said to be necessary to develop remote robotic systems, which have great potential of performing various tasks in nuclear facilities. Hence, we developed an advanced remote robotic system, consisting of redundant manipulator and environment-sensing systems, which can be applied to complicated handling tasks under unstructured environment. In the robotic system, various types of sensors for environment-sensing are mounted on the redundant manipulator and sensor-based autonomous capabilities are incorporated. This report describes the results of autonomous obstacle avoidance test which was carried out as follows: manipulating valves at the rear-side of wall, through a narrow window of the wall, with the redundant manipulator mounted on an x-axis driving mechanism. From this test, it is confirmed that the developed robotic system can autonomously achieve handling tasks in limited space as avoiding obstacles, which is supposed to be difficult by a non-redundant manipulator. (author)

  18. Long-distance fiber optic sensing solutions for pipeline leakage, intrusion, and ground movement detection

    Science.gov (United States)

    Nikles, Marc

    2009-05-01

    An increasing number of pipelines are constructed in remote regions affected by harsh environmental conditions where pipeline routes often cross mountain areas which are characterized by unstable grounds and where soil texture changes between winter and summer increase the probability of hazards. Third party intentional interference or accidental intrusions are a major cause of pipeline failures leading to large leaks or even explosions. Due to the long distances to be monitored and the linear nature of pipelines, distributed fiber optic sensing techniques offer significant advantages and the capability to detect and localize pipeline disturbance with great precision. Furthermore pipeline owner/operators lay fiber optic cable parallel to transmission pipelines for telecommunication purposes and at minimum additional cost monitoring capabilities can be added to the communication system. The Brillouin-based Omnisens DITEST monitoring system has been used in several long distance pipeline projects. The technique is capable of measuring strain and temperature over 100's kilometers with meter spatial resolution. Dedicated fiber optic cables have been developed for continuous strain and temperature monitoring and their deployment along the pipeline has enabled permanent and continuous pipeline ground movement, intrusion and leak detection. This paper presents a description of the fiber optic Brillouin-based DITEST sensing technique, its measurement performance and limits, while addressing future perspectives for pipeline monitoring. The description is supported by case studies and illustrated by field data.

  19. Adaptation of Dubins Paths for UAV Ground Obstacle Avoidance When Using a Low Cost On-Board GNSS Sensor

    Directory of Open Access Journals (Sweden)

    Ramūnas Kikutis

    2017-09-01

    Full Text Available Current research on Unmanned Aerial Vehicles (UAVs shows a lot of interest in autonomous UAV navigation. This interest is mainly driven by the necessity to meet the rules and restrictions for small UAV flights that are issued by various international and national legal organizations. In order to lower these restrictions, new levels of automation and flight safety must be reached. In this paper, a new method for ground obstacle avoidance derived by using UAV navigation based on the Dubins paths algorithm is presented. The accuracy of the proposed method has been tested, and research results have been obtained by using Software-in-the-Loop (SITL simulation and real UAV flights, with the measurements done with a low cost Global Navigation Satellite System (GNSS sensor. All tests were carried out in a three-dimensional space, but the height accuracy was not assessed. The GNSS navigation data for the ground obstacle avoidance algorithm is evaluated statistically.

  20. Adaptation of Dubins Paths for UAV Ground Obstacle Avoidance When Using a Low Cost On-Board GNSS Sensor.

    Science.gov (United States)

    Kikutis, Ramūnas; Stankūnas, Jonas; Rudinskas, Darius; Masiulionis, Tadas

    2017-09-28

    Current research on Unmanned Aerial Vehicles (UAVs) shows a lot of interest in autonomous UAV navigation. This interest is mainly driven by the necessity to meet the rules and restrictions for small UAV flights that are issued by various international and national legal organizations. In order to lower these restrictions, new levels of automation and flight safety must be reached. In this paper, a new method for ground obstacle avoidance derived by using UAV navigation based on the Dubins paths algorithm is presented. The accuracy of the proposed method has been tested, and research results have been obtained by using Software-in-the-Loop (SITL) simulation and real UAV flights, with the measurements done with a low cost Global Navigation Satellite System (GNSS) sensor. All tests were carried out in a three-dimensional space, but the height accuracy was not assessed. The GNSS navigation data for the ground obstacle avoidance algorithm is evaluated statistically.

  1. A survey of autonomous vision-based See and Avoid for Unmanned Aircraft Systems

    Science.gov (United States)

    Mcfadyen, Aaron; Mejias, Luis

    2016-01-01

    This paper provides a comprehensive review of the vision-based See and Avoid problem for unmanned aircraft. The unique problem environment and associated constraints are detailed, followed by an in-depth analysis of visual sensing limitations. In light of such detection and estimation constraints, relevant human, aircraft and robot collision avoidance concepts are then compared from a decision and control perspective. Remarks on system evaluation and certification are also included to provide a holistic review approach. The intention of this work is to clarify common misconceptions, realistically bound feasible design expectations and offer new research directions. It is hoped that this paper will help us to unify design efforts across the aerospace and robotics communities.

  2. City of Flagstaff Project: Ground Water Resource Evaluation, Remote Sensing Component

    Science.gov (United States)

    Chavez, Pat S.; Velasco, Miguel G.; Bowell, Jo-Ann; Sides, Stuart C.; Gonzalez, Rosendo R.; Soltesz, Deborah L.

    1996-01-01

    Many regions, cities, and towns in the Western United States need new or expanded water resources because of both population growth and increased development. Any tools or data that can help in the evaluation of an area's potential water resources must be considered for this increasingly critical need. Remotely sensed satellite images and subsequent digital image processing have been under-utilized in ground water resource evaluation and exploration. Satellite images can be helpful in detecting and mapping an area's regional structural patterns, including major fracture and fault systems, two important geologic settings for an area's surface to ground water relations. Within the United States Geological Survey's (USGS) Flagstaff Field Center, expertise and capabilities in remote sensing and digital image processing have been developed over the past 25 years through various programs. For the City of Flagstaff project, this expertise and these capabilities were combined with traditional geologic field mapping to help evaluate ground water resources in the Flagstaff area. Various enhancement and manipulation procedures were applied to the digital satellite images; the results, in both digital and hardcopy format, were used for field mapping and analyzing the regional structure. Relative to surface sampling, remotely sensed satellite and airborne images have improved spatial coverage that can help study, map, and monitor the earth surface at local and/or regional scales. Advantages offered by remotely sensed satellite image data include: 1. a synoptic/regional view compared to both aerial photographs and ground sampling, 2. cost effectiveness, 3. high spatial resolution and coverage compared to ground sampling, and 4. relatively high temporal coverage on a long term basis. Remotely sensed images contain both spectral and spatial information. The spectral information provides various properties and characteristics about the surface cover at a given location or pixel

  3. Ground-based transmission line conductor motion sensor

    International Nuclear Information System (INIS)

    Jacobs, M.L.; Milano, U.

    1988-01-01

    A ground-based-conductor motion-sensing apparatus is provided for remotely sensing movement of electric-power transmission lines, particularly as would occur during the wind-induced condition known as galloping. The apparatus is comprised of a motion sensor and signal-generating means which are placed underneath a transmission line and will sense changes in the electric field around the line due to excessive line motion. The detector then signals a remote station when a conditioning of galloping is sensed. The apparatus of the present invention is advantageous over the line-mounted sensors of the prior art in that it is easier and less hazardous to install. The system can also be modified so that a signal will only be given when particular conditions, such as specific temperature range, large-amplitude line motion, or excessive duration of the line motion, are occurring

  4. A Ground Systems Template for Remote Sensing Systems

    Science.gov (United States)

    McClanahan, Timothy P.; Trombka, Jacob I.; Floyd, Samuel R.; Truskowski, Walter; Starr, Richard D.; Clark, Pamela E.; Evans, Larry G.

    2002-10-01

    Spaceborne remote sensing using gamma and X-ray spectrometers requires particular attention to the design and development of reliable systems. These systems must ensure the scientific requirements of the mission within the challenging technical constraints of operating instrumentation in space. The Near Earth Asteroid Rendezvous (NEAR) spacecraft included X-ray and gamma-ray spectrometers (XGRS), whose mission was to map the elemental chemistry of the 433 Eros asteroid. A remote sensing system template, similar to a blackboard systems approach used in artificial intelligence, was identified in which the spacecraft, instrument, and ground system was designed and developed to monitor and adapt to evolving mission requirements in a complicated operational setting. Systems were developed for ground tracking of instrument calibration, instrument health, data quality, orbital geometry, solar flux as well as models of the asteroid's surface characteristics, requiring an intensive human effort. In the future, missions such as the Autonomous Nano-Technology Swarm (ANTS) program will have to rely heavily on automation to collectively encounter and sample asteroids in the outer asteroid belt. Using similar instrumentation, ANTS will require information similar to data collected by the NEAR X-ray/Gamma-Ray Spectrometer (XGRS) ground system for science and operations management. The NEAR XGRS systems will be studied to identify the equivalent subsystems that may be automated for ANTS. The effort will also investigate the possibility of applying blackboard style approaches to automated decision making required for ANTS.

  5. A ground systems template for remote sensing systems

    International Nuclear Information System (INIS)

    McClanahan, Timothy P.; Trombka, Jacob I.; Floyd, Samuel R.; Truskowski, Walter; Starr, Richard D.; Clark, Pamela E.; Evans, Larry G.

    2002-01-01

    Spaceborne remote sensing using gamma and X-ray spectrometers requires particular attention to the design and development of reliable systems. These systems must ensure the scientific requirements of the mission within the challenging technical constraints of operating instrumentation in space. The Near Earth Asteroid Rendezvous (NEAR) spacecraft included X-ray and gamma-ray spectrometers (XGRS), whose mission was to map the elemental chemistry of the 433 Eros asteroid. A remote sensing system template, similar to a blackboard systems approach used in artificial intelligence, was identified in which the spacecraft, instrument, and ground system was designed and developed to monitor and adapt to evolving mission requirements in a complicated operational setting. Systems were developed for ground tracking of instrument calibration, instrument health, data quality, orbital geometry, solar flux as well as models of the asteroid's surface characteristics, requiring an intensive human effort. In the future, missions such as the Autonomous Nano-Technology Swarm (ANTS) program will have to rely heavily on automation to collectively encounter and sample asteroids in the outer asteroid belt. Using similar instrumentation, ANTS will require information similar to data collected by the NEAR X-ray/Gamma-Ray Spectrometer (XGRS) ground system for science and operations management. The NEAR XGRS systems will be studied to identify the equivalent subsystems that may be automated for ANTS. The effort will also investigate the possibility of applying blackboard style approaches to automated decision making required for ANTS

  6. Head-Up Auditory Displays for Traffic Collision Avoidance System Advisories: A Preliminary Investigation

    Science.gov (United States)

    Begault, Durand R.

    1993-01-01

    The advantage of a head-up auditory display was evaluated in a preliminary experiment designed to measure and compare the acquisition time for capturing visual targets under two auditory conditions: standard one-earpiece presentation and two-earpiece three-dimensional (3D) audio presentation. Twelve commercial airline crews were tested under full mission simulation conditions at the NASA-Ames Man-Vehicle Systems Research Facility advanced concepts flight simulator. Scenario software generated visual targets corresponding to aircraft that would activate a traffic collision avoidance system (TCAS) aural advisory; the spatial auditory position was linked to the visual position with 3D audio presentation. Results showed that crew members using a 3D auditory display acquired targets approximately 2.2 s faster than did crew members who used one-earpiece head- sets, but there was no significant difference in the number of targets acquired.

  7. Affective three-dimensional brain-computer interface created using a prism array-based display

    Science.gov (United States)

    Mun, Sungchul; Park, Min-Chul

    2014-12-01

    To avoid the vergence-accommodation mismatch and provide a strong sense of presence to users, we applied a prism array-based display when presenting three-dimensional (3-D) objects. Emotional pictures were used as visual stimuli to increase the signal-to-noise ratios of steady-state visually evoked potentials (SSVEPs) because involuntarily motivated selective attention by affective mechanisms can enhance SSVEP amplitudes, thus producing increased interaction efficiency. Ten male and nine female participants voluntarily participated in our experiments. Participants were asked to control objects under three viewing conditions: two-dimension (2-D), stereoscopic 3-D, and prism. The participants performed each condition in a counter-balanced order. One-way repeated measures analysis of variance showed significant increases in the positive predictive values in the prism condition compared to the 2-D and 3-D conditions. Participants' subjective ratings of realness and engagement were also significantly greater in the prism condition than in the 2-D and 3-D conditions, while the ratings for visual fatigue were significantly reduced in the prism condition than in the 3-D condition. The proposed methods are expected to enhance the sense of reality in 3-D space without causing critical visual fatigue. In addition, people who are especially susceptible to stereoscopic 3-D may be able to use the affective brain-computer interface.

  8. Remote sensing of the lightning heating effect duration with ground-based microwave radiometer

    Science.gov (United States)

    Jiang, Sulin; Pan, Yun; Lei, Lianfa; Ma, Lina; Li, Qing; Wang, Zhenhui

    2018-06-01

    Artificially triggered lightning events from May 26, 2017 to July 16, 2017 in Guangzhou Field Experiment Site for Lightning Research and Test (GFESL) were intentionally remotely sensed with a ground-based microwave radiometer for the first time in order to obtain the features of lightning heating effect. The microwave radiometer antenna was adjusted to point at a certain elevation angle towards the expected artificially triggered lightning discharging path. Eight of the 16 successfully artificially triggered lightning events were captured and the brightness temperature data at four frequencies in K and V bands were obtained. The results from data time series analysis show that artificially triggered lightning can make the radiometer generate brightness temperature pulses, and the amplitudes of these pulses are in the range of 2.0 K to 73.8 K. The brightness temperature pulses associated with 7 events can be used to estimate the duration of lightning heating effect through accounting the number of the pulses in the continuous pulse sequence and the sampling interval between four frequencies. The maximum duration of the lightning heating effect is 1.13 s, the minimum is 0.172 s, and the average is 0.63 s.

  9. Ground and satellite-based remote sensing of mineral dust using AERI spectra and MODIS thermal infrared window brightness temperatures

    Science.gov (United States)

    Hansell, Richard Allen, Jr.

    The radiative effects of dust aerosol on our climate system have yet to be fully understood and remain a topic of contemporary research. To investigate these effects, detection/retrieval methods for dust events over major dust outbreak and transport areas have been developed using satellite and ground-based approaches. To this end, both the shortwave and longwave surface radiative forcing of dust aerosol were investigated. The ground-based remote sensing approach uses the Atmospheric Emitted Radiance Interferometer brightness temperature spectra to detect mineral dust events and to retrieve their properties. Taking advantage of the high spectral resolution of the AERI instrument, absorptive differences in prescribed thermal IR window sub-band channels were exploited to differentiate dust from cirrus clouds. AERI data collected during the UAE2 at Al-Ain UAE was employed for dust retrieval. Assuming a specified dust composition model a priori and using the light scattering programs of T-matrix and the finite difference time domain methods for oblate spheroids and hexagonal plates, respectively, dust optical depths have been retrieved and compared to those inferred from a collocated and coincident AERONET sun-photometer dataset. The retrieved optical depths were then used to determine the dust longwave surface forcing during the UAE2. Likewise, dust shortwave surface forcing is investigated employing a differential technique from previous field studies. The satellite-based approach uses MODIS thermal infrared brightness temperature window data for the simultaneous detection/separation of mineral dust and cirrus clouds. Based on the spectral variability of dust emissivity at the 3.75, 8.6, 11 and 12 mum wavelengths, the D*-parameter, BTD-slope and BTD3-11 tests are combined to identify dust and cirrus. MODIS data for the three dust-laden scenes have been analyzed to demonstrate the effectiveness of this detection/separation method. Detected daytime dust and cloud

  10. Microlaser-based displays

    Science.gov (United States)

    Bergstedt, Robert; Fink, Charles G.; Flint, Graham W.; Hargis, David E.; Peppler, Philipp W.

    1997-07-01

    Laser Power Corporation has developed a new type of projection display, based upon microlaser technology and a novel scan architecture, which provides the foundation for bright, extremely high resolution images. A review of projection technologies is presented along with the limitations of each and the difficulties they experience in trying to generate high resolution imagery. The design of the microlaser based projector is discussed along with the advantage of this technology. High power red, green, and blue microlasers have been designed and developed specifically for use in projection displays. These sources, in combination with high resolution, high contrast modulator, produce a 24 bit color gamut, capable of supporting the full range of real world colors. The new scan architecture, which reduces the modulation rate and scan speeds required, is described. This scan architecture, along with the inherent brightness of the laser provides the fundamentals necessary to produce a 5120 by 4096 resolution display. The brightness and color uniformity of the display is excellent, allowing for tiling of the displays with far fewer artifacts than those in a traditionally tiled display. Applications for the display include simulators, command and control centers, and electronic cinema.

  11. Assimilating Merged Remote Sensing and Ground based Snowpack Information for Runoff Simulation and Forecasting using Hydrological Models

    Science.gov (United States)

    Infante Corona, J. A.; Lakhankar, T.; Khanbilvardi, R.; Pradhanang, S. M.

    2013-12-01

    Stream flow estimation and flood prediction influenced by snow melting processes have been studied for the past couple of decades because of their destruction potential, money losses and demises. It has been observed that snow, that was very stationary during its seasons, now is variable in shorter time-scales (daily and hourly) and rapid snowmelt can contribute or been the cause of floods. Therefore, good estimates of snowpack properties on ground are necessary in order to have an accurate prediction of these destructive events. The snow thermal model (SNTHERM) is a 1-dimensional model that analyzes the snowpack properties given the climatological conditions of a particular area. Gridded data from both, in-situ meteorological observations and remote sensing data will be produced using interpolation methods; thus, snow water equivalent (SWE) and snowmelt estimations can be obtained. The soil and water assessment tool (SWAT) is a hydrological model capable of predicting runoff quantity and quality of a watershed given its main physical and hydrological properties. The results from SNTHERM will be used as an input for SWAT in order to have simulated runoff under snowmelt conditions. This project attempts to improve the river discharge estimation considering both, excess rainfall runoff and the snow melting process. Obtaining a better estimation of the snowpack properties and evolution is expected. A coupled use of SNTHERM and SWAT based on meteorological in situ and remote sensed data will improve the temporal and spatial resolution of the snowpack characterization and river discharge estimations, and thus flood prediction.

  12. Simultaneous multicopter-based air sampling and sensing of meteorological variables

    Science.gov (United States)

    Brosy, Caroline; Krampf, Karina; Zeeman, Matthias; Wolf, Benjamin; Junkermann, Wolfgang; Schäfer, Klaus; Emeis, Stefan; Kunstmann, Harald

    2017-08-01

    The state and composition of the lowest part of the planetary boundary layer (PBL), i.e., the atmospheric surface layer (SL), reflects the interactions of external forcing, land surface, vegetation, human influence and the atmosphere. Vertical profiles of atmospheric variables in the SL at high spatial (meters) and temporal (1 Hz and better) resolution increase our understanding of these interactions but are still challenging to measure appropriately. Traditional ground-based observations include towers that often cover only a few measurement heights at a fixed location. At the same time, most remote sensing techniques and aircraft measurements have limitations to achieve sufficient detail close to the ground (up to 50 m). Vertical and horizontal transects of the PBL can be complemented by unmanned aerial vehicles (UAV). Our aim in this case study is to assess the use of a multicopter-type UAV for the spatial sampling of air and simultaneously the sensing of meteorological variables for the study of the surface exchange processes. To this end, a UAV was equipped with onboard air temperature and humidity sensors, while wind conditions were determined from the UAV's flight control sensors. Further, the UAV was used to systematically change the location of a sample inlet connected to a sample tube, allowing the observation of methane abundance using a ground-based analyzer. Vertical methane gradients of about 0.3 ppm were found during stable atmospheric conditions. Our results showed that both methane and meteorological conditions were in agreement with other observations at the site during the ScaleX-2015 campaign. The multicopter-type UAV was capable of simultaneous in situ sensing of meteorological state variables and sampling of air up to 50 m above the surface, which extended the vertical profile height of existing tower-based infrastructure by a factor of 5.

  13. Magnetoseismology ground-based remote sensing of Earth's magnetosphere

    CERN Document Server

    Menk, Frederick W

    2013-01-01

    Written by a researcher at the forefront of the field, this first comprehensive account of magnetoseismology conveys the physics behind these movements and waves, and explains how to detect and investigate them. Along the way, it describes the principles as applied to remote sensing of near-Earth space and related remote sensing techniques, while also comparing and intercalibrating magnetoseismology with other techniques. The example applications include advanced data analysis techniques that may find wider used in areas ranging from geophysics to medical imaging, and remote sensing using radar systems that are of relevance to defense surveillance systems. As a result, the book not only reviews the status quo, but also anticipates new developments. With many figures and illustrations, some in full color, plus additional computational codes for analysis and evaluation. Aimed at graduate readers, the text assumes knowledge of electromagnetism and physical processes at degree level, but introductory chapters wil...

  14. Remote sensing of GHG over Paris megacity and Orléans forest using ground-based QualAir FTS and TCCON-Orléans

    Science.gov (United States)

    Te, Y.; Jeseck, P.; Da Costa, J.; Deutscher, N. M.; Warneke, T.; Notholt, J.

    2012-04-01

    In a growing world with more than 7 billion inhabitants and big emerging countries such as China, Brazil and India, emissions of anthropogenic pollutants are increasing continuously. Monitoring and control of atmospheric pollutants in megacities have become a major challenge for scientists and public health authorities in environmental research area. The QualAir platform at University Pierre et Marie Curie (UPMC), is an innovating experimental research platform dedicated to survey greenhouse gases (GHGs) and urban air quality. As one of the major instruments of the QualAir platform, the ground-based Fourier transform spectrometer (QualAir FTS, IFS 125HR model) analyses the composition of the urban atmosphere of Paris, which is the third European megacity. The continuous monitoring of atmospheric pollutants is essential to improve the understanding of urban air pollution processes. Associated with a sun-tracker, the QualAir remote sensing FTS operates in solar infrared absorption and enables to monitor many trace gases, and to follow up their variability in the Ile-de-France region. A description of the QualAir FTS will be given. Concentrations of atmospheric GHG, especially CO2 and CH4, are retrieved by the radiative transfer model PROFFIT. Located in the centre of Paris, the QualAir FTS can provide new and complementary urban measurements as compared to unpolluted ground-based stations of existing networks (NDACC and TCCON). The work made by LPMAA to join the TCCON network will also be presented. TCCON-Orléans is a ground-based FTS of the TCCON network located in the forest of Orléans (100 km south of Paris). Preliminary comparisons of GHGs measurements from both sites will be shown. Such ground-based information will help to better characterize regional GHGs, especially regarding anthropogenic emissions and trends.

  15. Optical gesture sensing and depth mapping technologies for head-mounted displays: an overview

    Science.gov (United States)

    Kress, Bernard; Lee, Johnny

    2013-05-01

    Head Mounted Displays (HMDs), and especially see-through HMDs have gained renewed interest in recent time, and for the first time outside the traditional military and defense realm, due to several high profile consumer electronics companies presenting their products to hit market. Consumer electronics HMDs have quite different requirements and constrains as their military counterparts. Voice comments are the de-facto interface for such devices, but when the voice recognition does not work (not connection to the cloud for example), trackpad and gesture sensing technologies have to be used to communicate information to the device. We review in this paper the various technologies developed today integrating optical gesture sensing in a small footprint, as well as the various related 3d depth mapping sensors.

  16. A Depth-Based Head-Mounted Visual Display to Aid Navigation in Partially Sighted Individuals

    Science.gov (United States)

    Hicks, Stephen L.; Wilson, Iain; Muhammed, Louwai; Worsfold, John; Downes, Susan M.; Kennard, Christopher

    2013-01-01

    Independent navigation for blind individuals can be extremely difficult due to the inability to recognise and avoid obstacles. Assistive techniques such as white canes, guide dogs, and sensory substitution provide a degree of situational awareness by relying on touch or hearing but as yet there are no techniques that attempt to make use of any residual vision that the individual is likely to retain. Residual vision can restricted to the awareness of the orientation of a light source, and hence any information presented on a wearable display would have to limited and unambiguous. For improved situational awareness, i.e. for the detection of obstacles, displaying the size and position of nearby objects, rather than including finer surface details may be sufficient. To test whether a depth-based display could be used to navigate a small obstacle course, we built a real-time head-mounted display with a depth camera and software to detect the distance to nearby objects. Distance was represented as brightness on a low-resolution display positioned close to the eyes without the benefit focussing optics. A set of sighted participants were monitored as they learned to use this display to navigate the course. All were able to do so, and time and velocity rapidly improved with practise with no increase in the number of collisions. In a second experiment a cohort of severely sight-impaired individuals of varying aetiologies performed a search task using a similar low-resolution head-mounted display. The majority of participants were able to use the display to respond to objects in their central and peripheral fields at a similar rate to sighted controls. We conclude that the skill to use a depth-based display for obstacle avoidance can be rapidly acquired and the simplified nature of the display may appropriate for the development of an aid for sight-impaired individuals. PMID:23844067

  17. Simulation of submillimetre atmospheric spectra for characterising potential ground-based remote sensing observations

    Directory of Open Access Journals (Sweden)

    E. C. Turner

    2016-11-01

    Full Text Available The submillimetre is an understudied region of the Earth's atmospheric electromagnetic spectrum. Prior technological gaps and relatively high opacity due to the prevalence of rotational water vapour lines at these wavelengths have slowed progress from a ground-based remote sensing perspective; however, emerging superconducting detector technologies in the fields of astronomy offer the potential to address key atmospheric science challenges with new instrumental methods. A site study, with a focus on the polar regions, is performed to assess theoretical feasibility by simulating the downwelling (zenith angle = 0° clear-sky submillimetre spectrum from 30 mm (10 GHz to 150 µm (2000 GHz at six locations under annual mean, summer, winter, daytime, night-time and low-humidity conditions. Vertical profiles of temperature, pressure and 28 atmospheric gases are constructed by combining radiosonde, meteorological reanalysis and atmospheric chemistry model data. The sensitivity of the simulated spectra to the choice of water vapour continuum model and spectroscopic line database is explored. For the atmospheric trace species hypobromous acid (HOBr, hydrogen bromide (HBr, perhydroxyl radical (HO2 and nitrous oxide (N2O the emission lines producing the largest change in brightness temperature are identified. Signal strengths, centre frequencies, bandwidths, estimated minimum integration times and maximum receiver noise temperatures are determined for all cases. HOBr, HBr and HO2 produce brightness temperature peaks in the mK to µK range, whereas the N2O peaks are in the K range. The optimal submillimetre remote sensing lines for the four species are shown to vary significantly between location and scenario, strengthening the case for future hyperspectral instruments that measure over a broad wavelength range. The techniques presented here provide a framework that can be applied to additional species of interest and taken forward to simulate

  18. Remote sensing of Sonoran Desert vegetation structure and phenology with ground-based LiDAR

    Science.gov (United States)

    Sankey, Joel B.; Munson, Seth M.; Webb, Robert H.; Wallace, Cynthia S.A.; Duran, Cesar M.

    2015-01-01

    Long-term vegetation monitoring efforts have become increasingly important for understanding ecosystem response to global change. Many traditional methods for monitoring can be infrequent and limited in scope. Ground-based LiDAR is one remote sensing method that offers a clear advancement to monitor vegetation dynamics at high spatial and temporal resolution. We determined the effectiveness of LiDAR to detect intra-annual variability in vegetation structure at a long-term Sonoran Desert monitoring plot dominated by cacti, deciduous and evergreen shrubs. Monthly repeat LiDAR scans of perennial plant canopies over the course of one year had high precision. LiDAR measurements of canopy height and area were accurate with respect to total station survey measurements of individual plants. We found an increase in the number of LiDAR vegetation returns following the wet North American Monsoon season. This intra-annual variability in vegetation structure detected by LiDAR was attributable to a drought deciduous shrub Ambrosia deltoidea, whereas the evergreen shrub Larrea tridentata and cactus Opuntia engelmannii had low variability. Benefits of using LiDAR over traditional methods to census desert plants are more rapid, consistent, and cost-effective data acquisition in a high-resolution, 3-dimensional context. We conclude that repeat LiDAR measurements can be an effective method for documenting ecosystem response to desert climatology and drought over short time intervals and at detailed-local spatial scale.

  19. Figure-ground segregation can rely on differences in motion direction.

    Science.gov (United States)

    Kandil, Farid I; Fahle, Manfred

    2004-12-01

    If the elements within a figure move synchronously while those in the surround move at a different time, the figure is easily segregated from the surround and thus perceived. Lee and Blake (1999) [Visual form created solely from temporal structure. Science, 284, 1165-1168] demonstrated that this figure-ground separation may be based not only on time differences between motion onsets, but also on the differences between reversals of motion direction. However, Farid and Adelson (2001) [Synchrony does not promote grouping in temporally structured displays. Nature Neuroscience, 4, 875-876] argued that figure-ground segregation in the motion-reversal experiment might have been based on a contrast artefact and concluded that (a)synchrony as such was 'not responsible for the perception of form in these or earlier displays'. Here, we present experiments that avoid contrast artefacts but still produce figure-ground segregation based on purely temporal cues. Our results show that subjects can segregate figure from ground even though being unable to use motion reversals as such. Subjects detect the figure when either (i) motion stops (leading to contrast artefacts), or (ii) motion directions differ between figure and ground. Segregation requires minimum delays of about 15 ms. We argue that whatever the underlying cues and mechanisms, a second stage beyond motion detection is required to globally compare the outputs of local motion detectors and to segregate figure from ground. Since analogous changes take place in both figure and ground in rapid succession, this second stage has to detect the asynchrony with high temporal precision.

  20. CLINICAL SURFACES - Activity-Based Computing for Distributed Multi-Display Environments in Hospitals

    Science.gov (United States)

    Bardram, Jakob E.; Bunde-Pedersen, Jonathan; Doryab, Afsaneh; Sørensen, Steffen

    A multi-display environment (MDE) is made up of co-located and networked personal and public devices that form an integrated workspace enabling co-located group work. Traditionally, MDEs have, however, mainly been designed to support a single “smart room”, and have had little sense of the tasks and activities that the MDE is being used for. This paper presents a novel approach to support activity-based computing in distributed MDEs, where displays are physically distributed across a large building. CLINICAL SURFACES was designed for clinical work in hospitals, and enables context-sensitive retrieval and browsing of patient data on public displays. We present the design and implementation of CLINICAL SURFACES, and report from an evaluation of the system at a large hospital. The evaluation shows that using distributed public displays to support activity-based computing inside a hospital is very useful for clinical work, and that the apparent contradiction between maintaining privacy of medical data in a public display environment can be mitigated by the use of CLINICAL SURFACES.

  1. Ground-based remote sensing observation of the complex behaviour of the Marseille boundary layer during ESCOMPTE

    Science.gov (United States)

    Delbarre, H.; Augustin, P.; Saïd, F.; Campistron, B.; Bénech, B.; Lohou, F.; Puygrenier, V.; Moppert, C.; Cousin, F.; Fréville, P.; Fréjafon, E.

    2005-03-01

    Ground-based remote sensing systems have been used during the ESCOMPTE campaign, to continuously characterize the boundary-layer behaviour through many atmospheric parameters (wind, extinction and ozone concentration distribution, reflectivity, turbulence). This analysis is focused on the comparison of the atmospheric stratification retrieved from a UV angular ozone lidar, an Ultra High Frequency wind profiler and a sodar, above the area of Marseille, on June 26th 2001 (Intensive Observation Period 2b). The atmospheric stratification is shown to be very complex including two superimposed sea breezes, with an important contribution of advection. The temporal and spatial evolution of the stratification observed by the UV lidar and by the UHF radar are in good agreement although the origin of the echoes of these systems is quite different. The complexity of the dynamic situation has only partially been retrieved by a non-hydrostatic mesoscale model used with a 3 km resolution.

  2. Positive deviance control-case life history: a method to develop grounded hypotheses about successful long-term avoidance of infection

    Directory of Open Access Journals (Sweden)

    Sandoval Milagros

    2008-03-01

    developed to stay safe. Staying Safe methodology develops grounded hypotheses. These can be tested through cohort studies of incidence and prevention trials of hypothesis-based programs to help drug injectors make their injection and sexual careers safer for themselves and others. This positive deviance control-case life history method might be used to study avoiding other infections like genital herpes among sex workers.

  3. Improving Agricultural Water Resources Management Using Ground-based Infrared Thermometry

    Science.gov (United States)

    Taghvaeian, S.

    2014-12-01

    Irrigated agriculture is the largest user of freshwater resources in arid/semi-arid parts of the world. Meeting rapidly growing demands in food, feed, fiber, and fuel while minimizing environmental pollution under a changing climate requires significant improvements in agricultural water management and irrigation scheduling. Although recent advances in remote sensing techniques and hydrological modeling has provided valuable information on agricultural water resources and their management, real improvements will only occur if farmers, the decision makers on the ground, are provided with simple, affordable, and practical tools to schedule irrigation events. This presentation reviews efforts in developing methods based on ground-based infrared thermometry and thermography for day-to-day management of irrigation systems. The results of research studies conducted in Colorado and Oklahoma show that ground-based remote sensing methods can be used effectively in quantifying water stress and consequently triggering irrigation events. Crop water use estimates based on stress indices have also showed to be in good agreement with estimates based on other methods (e.g. surface energy balance, root zone soil water balance, etc.). Major challenges toward the adoption of this approach by agricultural producers include the reduced accuracy under cloudy and humid conditions and its inability to forecast irrigation date, which is a critical knowledge since many irrigators need to decide about irrigations a few days in advance.

  4. Moving Object Tracking and Avoidance Algorithm for Differential Driving AGV Based on Laser Measurement Technology

    Directory of Open Access Journals (Sweden)

    Pandu Sandi Pratama

    2012-12-01

    Full Text Available This paper proposed an algorithm to track the obstacle position and avoid the moving objects for differential driving Automatic Guided Vehicles (AGV system in industrial environment. This algorithm has several abilities such as: to detect the moving objects, to predict the velocity and direction of moving objects, to predict the collision possibility and to plan the avoidance maneuver. For sensing the local environment and positioning, the laser measurement system LMS-151 and laser navigation system NAV-200 are applied. Based on the measurement results of the sensors, the stationary and moving obstacles are detected and the collision possibility is calculated. The velocity and direction of the obstacle are predicted using Kalman filter algorithm. Collision possibility, time, and position can be calculated by comparing the AGV movement and obstacle prediction result obtained by Kalman filter. Finally the avoidance maneuver using the well known tangent Bug algorithm is decided based on the calculation data. The effectiveness of proposed algorithm is verified using simulation and experiment. Several examples of experiment conditions are presented using stationary obstacle, and moving obstacles. The simulation and experiment results show that the AGV can detect and avoid the obstacles successfully in all experimental condition. [Keywords— Obstacle avoidance, AGV, differential drive, laser measurement system, laser navigation system].

  5. Avoiding maladaptation to climate change: towards guiding principles

    International Nuclear Information System (INIS)

    Magnan, Alexandre

    2013-08-01

    The recent publication of the Physical Science Basis volume of IPCC's Fifth Assessment Report reaffirms an already known conclusion: even drastic reductions of global greenhouse gas emissions will be insufficient to avoid some of the impacts of climate change, and is becoming increasingly clear that the temperature increase by the end of the century is likely to exceed the official target of +2 deg. C. Urgent efforts are thus more than ever needed to support socio-ecological systems threatened by climate change, but how to make adaptation happen on the ground remains vague. Consequently, there is a real risk that climate funding may support initiatives that are actually harmful for the socio-ecological systems, i.e. that foster adaptation in the short-term but insidiously affect systems' long-term vulnerability and/or adaptive capacity to climate change. This generally defines 'mal-adaptation', and this paper affirms that avoiding mal-adaptation is a first key concrete step towards adaptation in a broader sense. Focusing on coastal areas at a local scale and with the aim of providing insights to help avoiding mal-adaptation to climate change on the ground, this paper develops eleven practice-oriented guidelines that address the environmental, socio-cultural and economic dimensions of adaptation initiatives (policies, plans, projects). Based upon this, it affirms that the more guidelines an initiative addresses, the lower will be the risk of mal-adaptation. Together, these guidelines and this assumption constitute the 'Assessment framework' for approaching mal-adaptation to climate change at a local level. (author)

  6. Affective SSVEP BCI to effectively control 3D objects by using a prism array-based display

    Science.gov (United States)

    Mun, Sungchul; Park, Min-Chul

    2014-06-01

    3D objects with depth information can provide many benefits to users in education, surgery, and interactions. In particular, many studies have been done to enhance sense of reality in 3D interaction. Viewing and controlling stereoscopic 3D objects with crossed or uncrossed disparities, however, can cause visual fatigue due to the vergenceaccommodation conflict generally accepted in 3D research fields. In order to avoid the vergence-accommodation mismatch and provide a strong sense of presence to users, we apply a prism array-based display to presenting 3D objects. Emotional pictures were used as visual stimuli in control panels to increase information transfer rate and reduce false positives in controlling 3D objects. Involuntarily motivated selective attention by affective mechanism can enhance steady-state visually evoked potential (SSVEP) amplitude and lead to increased interaction efficiency. More attentional resources are allocated to affective pictures with high valence and arousal levels than to normal visual stimuli such as white-and-black oscillating squares and checkerboards. Among representative BCI control components (i.e., eventrelated potentials (ERP), event-related (de)synchronization (ERD/ERS), and SSVEP), SSVEP-based BCI was chosen in the following reasons. It shows high information transfer rates and takes a few minutes for users to control BCI system while few electrodes are required for obtaining reliable brainwave signals enough to capture users' intention. The proposed BCI methods are expected to enhance sense of reality in 3D space without causing critical visual fatigue to occur. In addition, people who are very susceptible to (auto) stereoscopic 3D may be able to use the affective BCI.

  7. Ground observations and remote sensing data for integrated modelisation of water budget in the Merguellil catchment, Tunisia

    Science.gov (United States)

    Mougenot, Bernard

    2016-04-01

    The Mediterranean region is affected by water scarcity. Some countries as Tunisia reached the limit of 550 m3/year/capita due overexploitation of low water resources for irrigation, domestic uses and industry. A lot of programs aim to evaluate strategies to improve water consumption at regional level. In central Tunisia, on the Merguellil catchment, we develop integrated water resources modelisations based on social investigations, ground observations and remote sensing data. The main objective is to close the water budget at regional level and to estimate irrigation and water pumping to test scenarios with endusers. Our works benefit from French, bilateral and European projects (ANR, MISTRALS/SICMed, FP6, FP7…), GMES/GEOLAND-ESA) and also network projects as JECAM and AERONET, where the Merguellil site is a reference. This site has specific characteristics associating irrigated and rainfed crops mixing cereals, market gardening and orchards and will be proposed as a new environmental observing system connected to the OMERE, TENSIFT and OSR systems respectively in Tunisia, Morocco and France. We show here an original and large set of ground and remote sensing data mainly acquired from 2008 to present to be used for calibration/validation of water budget processes and integrated models for present and scenarios: - Ground data: meteorological stations, water budget at local scale: fluxes tower, soil fluxes, soil and surface temperature, soil moisture, drainage, flow, water level in lakes, aquifer, vegetation parameters on selected fieds/month (LAI, height, biomass, yield), land cover: 3 times/year, bare soil roughness, irrigation and pumping estimations, soil texture. - Remote sensing data: remote sensing products from multi-platform (MODIS, SPOT, LANDSAT, ASTER, PLEIADES, ASAR, COSMO-SkyMed, TerraSAR X…), multi-wavelength (solar, micro-wave and thermal) and multi-resolution (0.5 meters to 1 km). Ground observations are used (1) to calibrate soil

  8. Application of a pilot control strategy identification technique to a joint FAA/NASA ground-based simulation of head-up displays for CTOL aircraft

    Science.gov (United States)

    Jewell, W. F.

    1982-01-01

    A technique for measuring a pilot's control strategy was developed, evaluated, and applied to a joint FAA-NASA ground-based simulation of two competing concepts of head-up displays for use in conventional takeoff and landing aircraft. The technique, called the Non-Intrusive Pilot Identification Program (NIPIP), estimates the pilot's input-output describing function and combined pilot-vehicle performance parameters such as crossover frequency and phase margin by using a time domain model of the pilot and a least-squares identification algorithm. NIPIP functions in realtime and uses a sliding time window to maintain freshness in the data; thus time-varying characteristics in the pilot's control strategy can be measured.

  9. Reconciling Ground-Based and Space-Based Estimates of the Frequency of Occurrence and Radiative Effect of Clouds around Darwin, Australia

    Energy Technology Data Exchange (ETDEWEB)

    Protat, Alain; Young, Stuart; McFarlane, Sally A.; L' Ecuyer, Tristan; Mace, Gerald G.; Comstock, Jennifer M.; Long, Charles N.; Berry, Elizabeth; Delanoe, Julien

    2014-02-01

    The objective of this paper is to investigate whether estimates of the cloud frequency of occurrence and associated cloud radiative forcing as derived from ground-based and satellite active remote sensing and radiative transfer calculations can be reconciled over a well instrumented active remote sensing site located in Darwin, Australia, despite the very different viewing geometry and instrument characteristics. It is found that the ground-based radar-lidar combination at Darwin does not detect most of the cirrus clouds above 10 km (due to limited lidar detection capability and signal obscuration by low-level clouds) and that the CloudSat radar - Cloud-Aerosol Lidar with Orthogonal Polarization (CALIOP) combination underreports the hydrometeor frequency of occurrence below 2 km height, due to instrument limitations at these heights. The radiative impact associated with these differences in cloud frequency of occurrence is large on the surface downwelling shortwave fluxes (ground and satellite) and the top-of atmosphere upwelling shortwave and longwave fluxes (ground). Good agreement is found for other radiative fluxes. Large differences in radiative heating rate as derived from ground and satellite radar-lidar instruments and RT calculations are also found above 10 km (up to 0.35 Kday-1 for the shortwave and 0.8 Kday-1 for the longwave). Given that the ground-based and satellite estimates of cloud frequency of occurrence and radiative impact cannot be fully reconciled over Darwin, caution should be exercised when evaluating the representation of clouds and cloud-radiation interactions in large-scale models and limitations of each set of instrumentation should be considered when interpreting model-observations differences.

  10. Effects of heat stress and probiotic supplementation on protein functionality and oxidative stability of ground chicken leg meat during display storage.

    Science.gov (United States)

    Kim, Hyun-Wook; Kim, Ji-Han; Yan, Feifei; Cheng, Heng-Wei; Brad Kim, Yuan H

    2017-12-01

    The present study aimed to evaluate the effects of heat stress and probiotic supplementation on protein functionality and oxidative stability of ground chicken leg during display storage. Two hundred and forty, 1-day-old male chicks (5 birds per pen) were subjected to four treatments in a 2 (thermoneutral condition at 21 °C and cyclic heat stress at 32-21-32 °C for 10 h day -1 ) × 2 (regular diet with 0 or 0.25 g kg -1 Bacillus subtilis) factorial design. Chickens were harvested at day 46, and pairs of whole legs were collected at 1 day postmortem. The chicken legs were deboned, ground, tray-packaged with oxygen-permeable film, and displayed for 3 days. Heat stress and probiotic supplementation had no impact on pH, water-holding capacity, color, protein functionality, lipid lipolysis and lipid/protein oxidation stability (P > 0.05). Display storage increased the pH and lipid oxidation of ground chicken legs (P chicken leg meat. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

  11. Sea Ice Thickness Measurement by Ground Penetrating Radar for Ground Truth of Microwave Remote Sensing Data

    Science.gov (United States)

    Matsumoto, M.; Yoshimura, M.; Naoki, K.; Cho, K.; Wakabayashi, H.

    2018-04-01

    Observation of sea ice thickness is one of key issues to understand regional effect of global warming. One of approaches to monitor sea ice in large area is microwave remote sensing data analysis. However, ground truth must be necessary to discuss the effectivity of this kind of approach. The conventional method to acquire ground truth of ice thickness is drilling ice layer and directly measuring the thickness by a ruler. However, this method is destructive, time-consuming and limited spatial resolution. Although there are several methods to acquire ice thickness in non-destructive way, ground penetrating radar (GPR) can be effective solution because it can discriminate snow-ice and ice-sea water interface. In this paper, we carried out GPR measurement in Lake Saroma for relatively large area (200 m by 300 m, approximately) aiming to obtain grand truth for remote sensing data. GPR survey was conducted at 5 locations in the area. The direct measurement was also conducted simultaneously in order to calibrate GPR data for thickness estimation and to validate the result. Although GPR Bscan image obtained from 600MHz contains the reflection which may come from a structure under snow, the origin of the reflection is not obvious. Therefore, further analysis and interpretation of the GPR image, such as numerical simulation, additional signal processing and use of 200 MHz antenna, are required to move on thickness estimation.

  12. Histogram-based ionogram displays and their application to autoscaling

    Science.gov (United States)

    Lynn, Kenneth J. W.

    2018-03-01

    A simple method is described for displaying and auto scaling the basic ionogram parameters foF2 and h'F2 as well as some additional layer parameters from digital ionograms. The technique employed is based on forming frequency and height histograms in each ionogram. This technique has now been applied specifically to ionograms produced by the IPS5D ionosonde developed and operated by the Australian Space Weather Service (SWS). The SWS ionograms are archived in a cleaned format and readily available from the SWS internet site. However, the method is applicable to any ionosonde which produces ionograms in a digital format at a useful signal-to-noise level. The most novel feature of the technique for autoscaling is its simplicity and the avoidance of the mathematical imaging and line fitting techniques often used. The program arose from the necessity to display many days of ionogram output to allow the location of specific types of ionospheric event such as ionospheric storms, travelling ionospheric disturbances and repetitive ionospheric height changes for further investigation and measurement. Examples and applications of the method are given including the removal of sporadic E and spread F.

  13. EmoHeart: Conveying Emotions in Second Life Based on Affect Sensing from Text

    Directory of Open Access Journals (Sweden)

    Alena Neviarouskaya

    2010-01-01

    Full Text Available The 3D virtual world of “Second Life” imitates a form of real life by providing a space for rich interactions and social events. Second Life encourages people to establish or strengthen interpersonal relations, to share ideas, to gain new experiences, and to feel genuine emotions accompanying all adventures of virtual reality. Undoubtedly, emotions play a powerful role in communication. However, to trigger visual display of user's affective state in a virtual world, user has to manually assign appropriate facial expression or gesture to own avatar. Affect sensing from text, which enables automatic expression of emotions in the virtual environment, is a method to avoid manual control by the user and to enrich remote communications effortlessly. In this paper, we describe a lexical rule-based approach to recognition of emotions from text and an application of the developed Affect Analysis Model in Second Life. Based on the result of the Affect Analysis Model, the developed EmoHeart (“object” in Second Life triggers animations of avatar facial expressions and visualizes emotion by heart-shaped textures.

  14. Automatic Barometric Updates from Ground-Based Navigational Aids

    Science.gov (United States)

    1990-03-12

    ro fAutomatic Barometric Updates US Department from of Transportation Ground-Based Federal Aviation Administration Navigational Aids Office of Safety...tighter vertical spacing controls , particularly for operations near Terminal Control Areas (TCAs), Airport Radar Service Areas (ARSAs), military climb and...E.F., Ruth, J.C., and Williges, B.H. (1987). Speech Controls and Displays. In Salvendy, G., E. Handbook of Human Factors/Ergonomics, New York, John

  15. Satellite and ground-based sensors for the Urban Heat Island analysis in the city of Rome

    DEFF Research Database (Denmark)

    Fabrizi, Roberto; Bonafoni, Stefania; Biondi, Riccardo

    2010-01-01

    In this work, the trend of the Urban Heat Island (UHI) of Rome is analyzed by both ground-based weather stations and a satellite-based infrared sensor. First, we have developed a suitable algorithm employing satellite brightness temperatures for the estimation of the air temperature belonging...... and nighttime scenes taken between 2003 and 2006 have been processed. Analysis of the Canopy Layer Heat Island (CLHI) during summer months reveals a mean growth in magnitude of 3-4 K during nighttime and a negative or almost zero CLHI intensity during daytime, confirmed by the weather stations. © 2010...... by the authors; licensee MDPI, Basel, Switzerland. Keyword: Thermal pollution,Summer months,Advanced-along track scanning radiometers,Urban heat island,Remote sensing,Canopy layer,Atmospheric temperature,Ground based sensors,Weather information services,Satellite remote sensing,Infra-red sensor,Weather stations...

  16. Real-Time and Seamless Monitoring of Ground-Level PM2.5 Using Satellite Remote Sensing

    Science.gov (United States)

    Li, Tongwen; Zhang, Chengyue; Shen, Huanfeng; Yuan, Qiangqiang; Zhang, Liangpei

    2018-04-01

    Satellite remote sensing has been reported to be a promising approach for the monitoring of atmospheric PM2.5. However, the satellite-based monitoring of ground-level PM2.5 is still challenging. First, the previously used polar-orbiting satellite observations, which can be usually acquired only once per day, are hard to monitor PM2.5 in real time. Second, many data gaps exist in satellitederived PM2.5 due to the cloud contamination. In this paper, the hourly geostationary satellite (i.e., Harawari-8) observations were adopted for the real-time monitoring of PM2.5 in a deep learning architecture. On this basis, the satellite-derived PM2.5 in conjunction with ground PM2.5 measurements are incorporated into a spatio-temporal fusion model to fill the data gaps. Using Wuhan Urban Agglomeration as an example, we have successfully derived the real-time and seamless PM2.5 distributions. The results demonstrate that Harawari-8 satellite-based deep learning model achieves a satisfactory performance (out-of-sample cross-validation R2 = 0.80, RMSE = 17.49 μg/m3) for the estimation of PM2.5. The missing data in satellite-derive PM2.5 are accurately recovered, with R2 between recoveries and ground measurements of 0.75. Overall, this study has inherently provided an effective strategy for the realtime and seamless monitoring of ground-level PM2.5.

  17. DE-STRIPING FOR TDICCD REMOTE SENSING IMAGE BASED ON STATISTICAL FEATURES OF HISTOGRAM

    Directory of Open Access Journals (Sweden)

    H.-T. Gao

    2016-06-01

    Full Text Available Aim to striping noise brought by non-uniform response of remote sensing TDI CCD, a novel de-striping method based on statistical features of image histogram is put forward. By analysing the distribution of histograms,the centroid of histogram is selected to be an eigenvalue representing uniformity of ground objects,histogrammic centroid of whole image and each pixels are calculated first,the differences between them are regard as rough correction coefficients, then in order to avoid the sensitivity caused by single parameter and considering the strong continuity and pertinence of ground objects between two adjacent pixels,correlation coefficient of the histograms is introduces to reflect the similarities between them,fine correction coefficient is obtained by searching around the rough correction coefficient,additionally,in view of the influence of bright cloud on histogram,an automatic cloud detection based on multi-feature including grey level,texture,fractal dimension and edge is used to pre-process image.Two 0-level panchromatic images of SJ-9A satellite with obvious strip noise are processed by proposed method to evaluate the performance, results show that the visual quality of images are improved because the strip noise is entirely removed,we quantitatively analyse the result by calculating the non-uniformity ,which has reached about 1% and is better than histogram matching method.

  18. Sensor-based whole-arm obstacle avoidance utilizing ASIC technology

    International Nuclear Information System (INIS)

    Wintenberg, A.L.; Ericson, M.N.; Babcock, S.M.; Armstrong, G.A.; Britton, C.L. Jr.; Butler, P.L.; Hamel, W.R.; Newport, D.F.

    1993-01-01

    Operation of manipulator systems in poorly defined work environments often presents a significant hazard to both the robotic assembly and the environment. In applications relating to the Environmental Restoration and Waste Management (ER ampersand WM) Program, many of the environments are considered hazardous, both, in the structure and composition of the environment Use of a sensing system that provides information to the manipulator control unit regarding obstacles in close proximity will provide protection against collisions. In this paper, a hierarchical design and implementation of a whole-arm obstacle avoidance system is presented. The system is based on capacitive sensors configured as bracelets for proximity sensing. Each bracelet contains a number of sensor nodes and a processor for sensor node control and readout, and communications with a higher level host, common to all bracelets. The host controls the entire sensing network and communicates proximity information to the manipulator controller. The overall architecture of this system is discussed with detail on the individual system modules. Details of an application specific integrated circuit (ASIC) designed to implement the sensor node electronics are presented. Justifications for the general measurement methods and associated implementation are discussed. Additionally, the current state of development including measured dam is presented

  19. SEA ICE THICKNESS MEASUREMENT BY GROUND PENETRATING RADAR FOR GROUND TRUTH OF MICROWAVE REMOTE SENSING DATA

    Directory of Open Access Journals (Sweden)

    M. Matsumoto

    2018-04-01

    Full Text Available Observation of sea ice thickness is one of key issues to understand regional effect of global warming. One of approaches to monitor sea ice in large area is microwave remote sensing data analysis. However, ground truth must be necessary to discuss the effectivity of this kind of approach. The conventional method to acquire ground truth of ice thickness is drilling ice layer and directly measuring the thickness by a ruler. However, this method is destructive, time-consuming and limited spatial resolution. Although there are several methods to acquire ice thickness in non-destructive way, ground penetrating radar (GPR can be effective solution because it can discriminate snow-ice and ice-sea water interface. In this paper, we carried out GPR measurement in Lake Saroma for relatively large area (200 m by 300 m, approximately aiming to obtain grand truth for remote sensing data. GPR survey was conducted at 5 locations in the area. The direct measurement was also conducted simultaneously in order to calibrate GPR data for thickness estimation and to validate the result. Although GPR Bscan image obtained from 600MHz contains the reflection which may come from a structure under snow, the origin of the reflection is not obvious. Therefore, further analysis and interpretation of the GPR image, such as numerical simulation, additional signal processing and use of 200 MHz antenna, are required to move on thickness estimation.

  20. Remote sensing observation used in offshore wind energy

    DEFF Research Database (Denmark)

    Hasager, Charlotte Bay; Pena Diaz, Alfredo; Christiansen, Merete Bruun

    2008-01-01

    Remote sensing observations used in offshore wind energy are described in three parts: ground-based techniques and applications, airborne techniques and applications, and satellite-based techniques and applications. Ground-based remote sensing of winds is relevant, in particular, for new large wind...

  1. A novel technique for extracting clouds base height using ground based imaging

    Directory of Open Access Journals (Sweden)

    E. Hirsch

    2011-01-01

    Full Text Available The height of a cloud in the atmospheric column is a key parameter in its characterization. Several remote sensing techniques (passive and active, either ground-based or on space-borne platforms and in-situ measurements are routinely used in order to estimate top and base heights of clouds. In this article we present a novel method that combines thermal imaging from the ground and sounded wind profile in order to derive the cloud base height. This method is independent of cloud types, making it efficient for both low boundary layer and high clouds. In addition, using thermal imaging ensures extraction of clouds' features during daytime as well as at nighttime. The proposed technique was validated by comparison to active sounding by ceilometers (which is a standard ground based method, to lifted condensation level (LCL calculations, and to MODIS products obtained from space. As all passive remote sensing techniques, the proposed method extracts only the height of the lowest cloud layer, thus upper cloud layers are not detected. Nevertheless, the information derived from this method can be complementary to space-borne cloud top measurements when deep-convective clouds are present. Unlike techniques such as LCL, this method is not limited to boundary layer clouds, and can extract the cloud base height at any level, as long as sufficient thermal contrast exists between the radiative temperatures of the cloud and its surrounding air parcel. Another advantage of the proposed method is its simplicity and modest power needs, making it particularly suitable for field measurements and deployment at remote locations. Our method can be further simplified for use with visible CCD or CMOS camera (although nighttime clouds will not be observed.

  2. Ground Albedo Neutron Sensing (GANS) for Measurement of Integral Soil Water Content at the Small Catchment Scale

    Science.gov (United States)

    Rivera Villarreyes, C.; Baroni, G.; Oswald, S. E.

    2012-12-01

    Soil water content at the plot or hill-slope scale is an important link between local vadose zone hydrology and catchment hydrology. One largest initiative to cover the measuring gap of soil moisture between point scale and remote sensing observations is the COSMOS network (Zreda et al., 2012). Here, cosmic-ray neutron sensing, which may be more precisely named ground albedo neutron sensing (GANS), is applied. The measuring principle is based on the crucial role of hydrogen as neutron moderator compared to others landscape materials. Soil water content contained in a footprint of ca. 600 m diameter and a depth ranging down to a few decimeters is inversely correlated to the neutron flux at the air-ground interface. This approach is now implemented, e.g. in USA (Zreda et al., 2012) and Germany (Rivera Villarreyes et al., 2011), based on its simple installation and integral measurement of soil moisture at the small catchment scale. The present study performed Ground Albedo Neutron Sensing on farmland at two locations in Germany under different vegetative situations (cropped and bare field) and different seasonal conditions (summer, autumn and winter). Ground albedo neutrons were measured at (i) a farmland close to Potsdam and Berlin cropped with corn in 2010, sunflower in 2011 and winter rye in 2012, and (ii) a mountainous farmland catchment (Schaefertal, Harz Mountains) since middle 2011. In order to test this methodology, classical soil moisture devices and meteorological data were used for comparison. Moreover, several calibration approaches, role of vegetation cover and transferability of calibration parameters to different times and locations were also evaluated. Observations suggest that GANS can overcome the lack of data for hydrological processes at the intermediate scale. Soil moisture from GANS compared quantitatively with mean values derived from a network of classical devices under vegetated and non- vegetated conditions. The GANS approach responded well

  3. Electrolocation-based underwater obstacle avoidance using wide-field integration methods

    International Nuclear Information System (INIS)

    Dimble, Kedar D; Faddy, James M; Humbert, J Sean

    2014-01-01

    Weakly electric fish are capable of efficiently performing obstacle avoidance in dark and navigationally challenging aquatic environments using electrosensory information. This sensory modality enables extraction of relevant proximity information about surrounding obstacles by interpretation of perturbations induced to the fish’s self-generated electric field. In this paper, reflexive obstacle avoidance is demonstrated by extracting relative proximity information using spatial decompositions of the perturbation signal, also called an electric image. Electrostatics equations were formulated for mathematically expressing electric images due to a straight tunnel to the electric field generated with a planar electro-sensor model. These equations were further used to design a wide-field integration based static output feedback controller. The controller was implemented in quasi-static simulations for environments with complicated geometries modelled using finite element methods to demonstrate sense and avoid behaviours. The simulation results were confirmed by performing experiments using a computer operated gantry system in environments lined with either conductive or non-conductive objects acting as global stimuli to the field of the electro-sensor. The proposed approach is computationally inexpensive and readily implementable, making underwater autonomous navigation in real-time feasible. (paper)

  4. Compressed sensing approach for wrist vein biometrics.

    Science.gov (United States)

    Lantsov, Aleksey; Ryabko, Maxim; Shchekin, Aleksey

    2018-04-01

    The work describes features of the compressed sensing (CS) approach utilized for development of a wearable system for wrist vein recognition with single-pixel detection; we consider this system useful for biometrics authentication purposes. The CS approach implies use of a spatial light modulation (SLM) which, in our case, can be performed differently-with a liquid crystal display or diffusely scattering medium. We show that compressed sensing combined with above-mentioned means of SLM allows us to avoid using an optical system-a limiting factor for wearable devices. The trade-off between the 2 different SLM approaches regarding issues of practical implementation of CS approach for wrist vein recognition purposes is discussed. A possible solution of a misalignment problem-a typical issue for imaging systems based upon 2D arrays of photodiodes-is also proposed. Proposed design of the wearable device for wrist vein recognition is based upon single-pixel detection. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  5. Remote Sensing of Sonoran Desert Vegetation Structure and Phenology with Ground-Based LiDAR

    Directory of Open Access Journals (Sweden)

    Joel B. Sankey

    2014-12-01

    Full Text Available Long-term vegetation monitoring efforts have become increasingly important for understanding ecosystem response to global change. Many traditional methods for monitoring can be infrequent and limited in scope. Ground-based LiDAR is one remote sensing method that offers a clear advancement to monitor vegetation dynamics at high spatial and temporal resolution. We determined the effectiveness of LiDAR to detect intra-annual variability in vegetation structure at a long-term Sonoran Desert monitoring plot dominated by cacti, deciduous and evergreen shrubs. Monthly repeat LiDAR scans of perennial plant canopies over the course of one year had high precision. LiDAR measurements of canopy height and area were accurate with respect to total station survey measurements of individual plants. We found an increase in the number of LiDAR vegetation returns following the wet North American Monsoon season. This intra-annual variability in vegetation structure detected by LiDAR was attributable to a drought deciduous shrub Ambrosia deltoidea, whereas the evergreen shrub Larrea tridentata and cactus Opuntia engelmannii had low variability. Benefits of using LiDAR over traditional methods to census desert plants are more rapid, consistent, and cost-effective data acquisition in a high-resolution, 3-dimensional context. We conclude that repeat LiDAR measurements can be an effective method for documenting ecosystem response to desert climatology and drought over short time intervals and at detailed-local spatial scale.

  6. [Comparison of precision in retrieving soybean leaf area index based on multi-source remote sensing data].

    Science.gov (United States)

    Gao, Lin; Li, Chang-chun; Wang, Bao-shan; Yang Gui-jun; Wang, Lei; Fu, Kui

    2016-01-01

    With the innovation of remote sensing technology, remote sensing data sources are more and more abundant. The main aim of this study was to analyze retrieval accuracy of soybean leaf area index (LAI) based on multi-source remote sensing data including ground hyperspectral, unmanned aerial vehicle (UAV) multispectral and the Gaofen-1 (GF-1) WFV data. Ratio vegetation index (RVI), normalized difference vegetation index (NDVI), soil-adjusted vegetation index (SAVI), difference vegetation index (DVI), and triangle vegetation index (TVI) were used to establish LAI retrieval models, respectively. The models with the highest calibration accuracy were used in the validation. The capability of these three kinds of remote sensing data for LAI retrieval was assessed according to the estimation accuracy of models. The experimental results showed that the models based on the ground hyperspectral and UAV multispectral data got better estimation accuracy (R² was more than 0.69 and RMSE was less than 0.4 at 0.01 significance level), compared with the model based on WFV data. The RVI logarithmic model based on ground hyperspectral data was little superior to the NDVI linear model based on UAV multispectral data (The difference in E(A), R² and RMSE were 0.3%, 0.04 and 0.006, respectively). The models based on WFV data got the lowest estimation accuracy with R2 less than 0.30 and RMSE more than 0.70. The effects of sensor spectral response characteristics, sensor geometric location and spatial resolution on the soybean LAI retrieval were discussed. The results demonstrated that ground hyperspectral data were advantageous but not prominent over traditional multispectral data in soybean LAI retrieval. WFV imagery with 16 m spatial resolution could not meet the requirements of crop growth monitoring at field scale. Under the condition of ensuring the high precision in retrieving soybean LAI and working efficiently, the approach to acquiring agricultural information by UAV remote

  7. LightForce: An Update on Orbital Collision Avoidance Using Photon Pressure

    Science.gov (United States)

    Stupl, Jan; Mason, James; De Vries, Willem; Smith, Craig; Levit, Creon; Marshall, William; Salas, Alberto Guillen; Pertica, Alexander; Olivier, Scot; Ting, Wang

    2012-01-01

    We present an update on our research on collision avoidance using photon-pressure induced by ground-based lasers. In the past, we have shown the general feasibility of employing small orbit perturbations, induced by photon pressure from ground-based laser illumination, for collision avoidance in space. Possible applications would be protecting space assets from impacts with debris and stabilizing the orbital debris environment. Focusing on collision avoidance rather than de-orbit, the scheme avoids some of the security and liability implications of active debris removal, and requires less sophisticated hardware than laser ablation. In earlier research we concluded that one ground based system consisting of a 10 kW class laser, directed by a 1.5 m telescope with adaptive optics, could avoid a significant fraction of debris-debris collisions in low Earth orbit. This paper describes our recent efforts, which include refining our original analysis, employing higher fidelity simulations and performing experimental tracking tests. We investigate the efficacy of one or more laser ground stations for debris-debris collision avoidance and satellite protection using simulations to investigate multiple case studies. The approach includes modeling of laser beam propagation through the atmosphere, the debris environment (including actual trajectories and physical parameters), laser facility operations, and simulations of the resulting photon pressure. We also present the results of experimental laser debris tracking tests. These tests track potential targets of a first technical demonstration and quantify the achievable tracking performance.

  8. Time and constitution of sense

    Directory of Open Access Journals (Sweden)

    Pedro Gerardo Acosta

    2014-06-01

    Full Text Available This article proposes a reflection over our time-consciousness under the Phenomenology of Edmund Husserl. The idea is make a release the key role of the sense constitution like the fundament and development of the ongoing intentionality, a shape that make the possibility to catch sight of the sense of every life situation like conscience experience that displays itself over the time, and open the world of the Phenomenon World, constituted in the flux and flow of our live experience. The immanent time in which the things served in a lived-present inevitably displays to its own immediate-past of retentions, then of commemorations, constituting and enabling, not just the sense of ever present, but the sense of our own past like memory and our future like expectative. This reflection is based and supporter over the text “Phenomenology Lesson of the Internal Time-Consiusness” (Husserl, 2002.

  9. Human Walking Pattern Recognition Based on KPCA and SVM with Ground Reflex Pressure Signal

    Directory of Open Access Journals (Sweden)

    Zhaoqin Peng

    2013-01-01

    Full Text Available Algorithms based on the ground reflex pressure (GRF signal obtained from a pair of sensing shoes for human walking pattern recognition were investigated. The dimensionality reduction algorithms based on principal component analysis (PCA and kernel principal component analysis (KPCA for walking pattern data compression were studied in order to obtain higher recognition speed. Classifiers based on support vector machine (SVM, SVM-PCA, and SVM-KPCA were designed, and the classification performances of these three kinds of algorithms were compared using data collected from a person who was wearing the sensing shoes. Experimental results showed that the algorithm fusing SVM and KPCA had better recognition performance than the other two methods. Experimental outcomes also confirmed that the sensing shoes developed in this paper can be employed for automatically recognizing human walking pattern in unlimited environments which demonstrated the potential application in the control of exoskeleton robots.

  10. Avoiding genetically modified foods in GMO Ground Zero: A reflective self-narrative.

    Science.gov (United States)

    Edwards, Sachi

    2015-05-01

    I engage in a reflective self-narrative of my experience attempting to maintain a diet free of genetically modified organisms. Social tension over the genetically modified organism industry in Hawai'i, United States, has led to public debates over jobs and social identities. Drawing on local media sources, grassroots organizations, and blog posts, I describe the way this tension has shaped my experience with food, eating, and being with others as a genetically modified organism avoider. I utilize discursive positioning to make sense of my experiences by locating them within the ongoing public conversations that give structure to the daily lives of Hawai'i's residents. © The Author(s) 2015.

  11. Real-Time Hazard Detection and Avoidance Demonstration for a Planetary Lander

    Science.gov (United States)

    Epp, Chirold D.; Robertson, Edward A.; Carson, John M., III

    2014-01-01

    The Autonomous Landing Hazard Avoidance Technology (ALHAT) Project is chartered to develop and mature to a Technology Readiness Level (TRL) of six an autonomous system combining guidance, navigation and control with terrain sensing and recognition functions for crewed, cargo, and robotic planetary landing vehicles. In addition to precision landing close to a pre-mission defined landing location, the ALHAT System must be capable of autonomously identifying and avoiding surface hazards in real-time to enable a safe landing under any lighting conditions. This paper provides an overview of the recent results of the ALHAT closed loop hazard detection and avoidance flight demonstrations on the Morpheus Vertical Testbed (VTB) at the Kennedy Space Center, including results and lessons learned. This effort is also described in the context of a technology path in support of future crewed and robotic planetary exploration missions based upon the core sensing functions of the ALHAT system: Terrain Relative Navigation (TRN), Hazard Detection and Avoidance (HDA), and Hazard Relative Navigation (HRN).

  12. [Estimation of desert vegetation coverage based on multi-source remote sensing data].

    Science.gov (United States)

    Wan, Hong-Mei; Li, Xia; Dong, Dao-Rui

    2012-12-01

    Taking the lower reaches of Tarim River in Xinjiang of Northwest China as study areaAbstract: Taking the lower reaches of Tarim River in Xinjiang of Northwest China as study area and based on the ground investigation and the multi-source remote sensing data of different resolutions, the estimation models for desert vegetation coverage were built, with the precisions of different estimation methods and models compared. The results showed that with the increasing spatial resolution of remote sensing data, the precisions of the estimation models increased. The estimation precision of the models based on the high, middle-high, and middle-low resolution remote sensing data was 89.5%, 87.0%, and 84.56%, respectively, and the precisions of the remote sensing models were higher than that of vegetation index method. This study revealed the change patterns of the estimation precision of desert vegetation coverage based on different spatial resolution remote sensing data, and realized the quantitative conversion of the parameters and scales among the high, middle, and low spatial resolution remote sensing data of desert vegetation coverage, which would provide direct evidence for establishing and implementing comprehensive remote sensing monitoring scheme for the ecological restoration in the study area.

  13. Vision based flight procedure stereo display system

    Science.gov (United States)

    Shen, Xiaoyun; Wan, Di; Ma, Lan; He, Yuncheng

    2008-03-01

    A virtual reality flight procedure vision system is introduced in this paper. The digital flight map database is established based on the Geographic Information System (GIS) and high definitions satellite remote sensing photos. The flight approaching area database is established through computer 3D modeling system and GIS. The area texture is generated from the remote sensing photos and aerial photographs in various level of detail. According to the flight approaching procedure, the flight navigation information is linked to the database. The flight approaching area vision can be dynamic displayed according to the designed flight procedure. The flight approaching area images are rendered in 2 channels, one for left eye images and the others for right eye images. Through the polarized stereoscopic projection system, the pilots and aircrew can get the vivid 3D vision of the flight destination approaching area. Take the use of this system in pilots preflight preparation procedure, the aircrew can get more vivid information along the flight destination approaching area. This system can improve the aviator's self-confidence before he carries out the flight mission, accordingly, the flight safety is improved. This system is also useful in validate the visual flight procedure design, and it helps to the flight procedure design.

  14. A compressive sensing-based computational method for the inversion of wide-band ground penetrating radar data

    Science.gov (United States)

    Gelmini, A.; Gottardi, G.; Moriyama, T.

    2017-10-01

    This work presents an innovative computational approach for the inversion of wideband ground penetrating radar (GPR) data. The retrieval of the dielectric characteristics of sparse scatterers buried in a lossy soil is performed by combining a multi-task Bayesian compressive sensing (MT-BCS) solver and a frequency hopping (FH) strategy. The developed methodology is able to benefit from the regularization capabilities of the MT-BCS as well as to exploit the multi-chromatic informative content of GPR measurements. A set of numerical results is reported in order to assess the effectiveness of the proposed GPR inverse scattering technique, as well as to compare it to a simpler single-task implementation.

  15. Ground-Based Observations and Modeling of the Visibility and Radar Reflectivity in a Radiation Fog Layer

    NARCIS (Netherlands)

    Boers, R.; Baltink, K.H.; Hemink, H.J.; Bosveld, F.C.; Moerman, M.

    2013-01-01

    The development of a radiation fog layer at the Cabauw Experimental Site for Atmospheric Research(51.97°N, 4.93°E) on 23 March 2011 was observed with ground-based in situ and remote sensing observationsto investigate the relationship between visibility and radar reflectivity. The fog layer thickness

  16. Cross Validation of Rain Drop Size Distribution between GPM and Ground Based Polarmetric radar

    Science.gov (United States)

    Chandra, C. V.; Biswas, S.; Le, M.; Chen, H.

    2017-12-01

    Dual-frequency precipitation radar (DPR) on board the Global Precipitation Measurement (GPM) core satellite has reflectivity measurements at two independent frequencies, Ku- and Ka- band. Dual-frequency retrieval algorithms have been developed traditionally through forward, backward, and recursive approaches. However, these algorithms suffer from "dual-value" problem when they retrieve medium volume diameter from dual-frequency ratio (DFR) in rain region. To this end, a hybrid method has been proposed to perform raindrop size distribution (DSD) retrieval for GPM using a linear constraint of DSD along rain profile to avoid "dual-value" problem (Le and Chandrasekar, 2015). In the current GPM level 2 algorithm (Iguchi et al. 2017- Algorithm Theoretical Basis Document) the Solver module retrieves a vertical profile of drop size distributionn from dual-frequency observations and path integrated attenuations. The algorithm details can be found in Seto et al. (2013) . On the other hand, ground based polarimetric radars have been used for a long time to estimate drop size distributions (e.g., Gorgucci et al. 2002 ). In addition, coincident GPM and ground based observations have been cross validated using careful overpass analysis. In this paper, we perform cross validation on raindrop size distribution retrieval from three sources, namely the hybrid method, the standard products from the solver module and DSD retrievals from ground polarimetric radars. The results are presented from two NEXRAD radars located in Dallas -Fort Worth, Texas (i.e., KFWS radar) and Melbourne, Florida (i.e., KMLB radar). The results demonstrate the ability of DPR observations to produce DSD estimates, which can be used subsequently to generate global DSD maps. References: Seto, S., T. Iguchi, T. Oki, 2013: The basic performance of a precipitation retrieval algorithm for the Global Precipitation Measurement mission's single/dual-frequency radar measurements. IEEE Transactions on Geoscience and

  17. INFORMATION DISPLAY: CONSIDERATIONS FOR DESIGNING COMPUTER-BASED DISPLAY SYSTEMS

    International Nuclear Information System (INIS)

    O'HARA, J.M.; PIRUS, D.; BELTRATCCHI, L.

    2004-01-01

    This paper discussed the presentation of information in computer-based control rooms. Issues associated with the typical displays currently in use are discussed. It is concluded that these displays should be augmented with new displays designed to better meet the information needs of plant personnel and to minimize the need for interface management tasks (the activities personnel have to do to access and organize the information they need). Several approaches to information design are discussed, specifically addressing: (1) monitoring, detection, and situation assessment; (2) routine task performance; and (3) teamwork, crew coordination, collaborative work

  18. Mechanisms of time-based figure-ground segregation.

    Science.gov (United States)

    Kandil, Farid I; Fahle, Manfred

    2003-11-01

    Figure-ground segregation can rely on purely temporal information, that is, on short temporal delays between positional changes of elements in figure and ground (Kandil, F.I. & Fahle, M. (2001) Eur. J. Neurosci., 13, 2004-2008). Here, we investigate the underlying mechanisms by measuring temporal segregation thresholds for various kinds of motion cues. Segregation can rely on monocular first-order motion (based on luminance modulation) and second-order motion cues (contrast modulation) with a high temporal resolution of approximately 20 ms. The mechanism can also use isoluminant motion with a reduced temporal resolution of 60 ms. Figure-ground segregation can be achieved even at presentation frequencies too high for human subjects to inspect successive frames individually. In contrast, when stimuli are presented dichoptically, i.e. separately to both eyes, subjects are unable to perceive any segregation, irrespective of temporal frequency. We propose that segregation in these displays is detected by a mechanism consisting of at least two stages. On the first level, standard motion or flicker detectors signal local positional changes (flips). On the second level, a segregation mechanism combines the local activities of the low-level detectors with high temporal precision. Our findings suggest that the segregation mechanism can rely on monocular detectors but not on binocular mechanisms. Moreover, the results oppose the idea that segregation in these displays is achieved by motion detectors of a higher order (motion-from-motion), but favour mechanisms sensitive to short temporal delays even without activation of higher-order motion detectors.

  19. Study of Diagenetic Features in Rudist Buildups of Cretaceous Edwards Formation Using Ground Based Hyperspectral Scanning and Terrestrial LiDAR

    Science.gov (United States)

    Krupnik, D.; Khan, S.; Okyay, U.; Hartzell, P. J.; Biber, K.

    2015-12-01

    Ground based remote sensing is a novel technique for development of digital outcrop models which can be instrumental in performing detailed qualitative and quantitative sedimentological analysis for the study of depositional environment, diagenetic processes, and hydrocarbon reservoir characterization. For this investigation, ground-based hyperspectral data collection is combined with terrestrial LiDAR to study outcrops of Late Albian rudist buildups of the Edwards formation in the Lake Georgetown Spillway in Williamson County, Texas. The Edwards formation consists of shallow water deposits of reef and associated inter-reef facies, including rudist bioherms and biostromes. It is a significant aquifer and was investigated as a hydrocarbon play in south central Texas. Hyperspectral data were used to map compositional variation in the outcrop by distinguishing spectral properties unique to each material. Lithological variation was mapped in detail to investigate the structure and composition of rudist buildups. Hyperspectral imagery was registered to a 3D model produced from the LiDAR point cloud with an accuracy of up to one pixel. Flat-topped toucasid-rich bioherm facies were distinguished from overlying toucasid-rich biostrome facies containing chert nodules, overlying sucrosic dolostones, and uppermost peloid wackestones and packstones of back-reef facies. Ground truth was established by petrographic study of samples from this area and has validated classification products of remote sensing data. Several types of porosity were observed and have been associated with increased dolomitization. This ongoing research involves integration of remotely sensed datasets to analyze geometrical and compositional properties of this carbonate formation at a finer scale than traditional methods have achieved and seeks to develop a workflow for quick and efficient ground based remote sensing-assisted outcrop studies.

  20. The effect of spectroscopic parameter inaccuracies on ground-based millimeter wave remote sensing of the atmosphere

    International Nuclear Information System (INIS)

    Ryan, Niall J.; Walker, Kaley A.

    2015-01-01

    A sensitivity study was performed to assess the impact that uncertainties in the spectroscopic parameters of atmospheric species have on the retrieval of gas concentrations using the 265–280 GHz region of the electromagnetic spectrum. Errors in the retrieval of O 3 , N 2 O, HNO 3 , and ClO from spectra measured by ground-based radiometers were investigated. The goal of the study was to identify the spectroscopic parameters of these target species, and other interfering species, available in the JPL and HITRAN 2008 catalogues, which contribute the largest error to retrieved atmospheric concentration profiles in order to provide recommendations for new laboratory measurements. The parameters investigated were the line position, line strength, broadening coefficients and their temperature dependence, and pressure shift. Uncertainties in the air broadening coefficients of gases tend to contribute the largest error to retrieved atmospheric concentration profiles. For O 3 and N 2 O, gases with relatively strong spectral signatures, the retrieval is sensitive to uncertainties in the parameters of the main spectral line that is observed. For HNO 3 , the uncertainties in many closely spaced HNO 3 lines can cause large errors in the retrieved profile, and for ClO, the error in the profile is dominated by uncertainties in nearby, stronger O 3 lines. Fourteen spectroscopic parameters are identified, for which updated measurements would have the most impact on the accuracy of ground-based remote sensing of the target species at 265–280 GHz. - Highlights: • The sensitivity of retrievals to spectroscopic parameters is assessed. • Air broadening parameters contribute the most to the error budget. • O 3 and N 2 O retrievals are sensitive to parameters of the target spectral lines. • Many HNO 3 lines in close proximity can cause large errors in HNO 3 retrievals. • ClO retrievals are sensitive to uncertainties in parameters of nearby O 3 lines

  1. Development of a data driven process-based model for remote sensing of terrestrial ecosystem productivity, evapotranspiration, and above-ground biomass

    Science.gov (United States)

    El Masri, Bassil

    2011-12-01

    Modeling terrestrial ecosystem functions and structure has been a subject of increasing interest because of the importance of the terrestrial carbon cycle in global carbon budget and climate change. In this study, satellite data were used to estimate gross primary production (GPP), evapotranspiration (ET) for two deciduous forests: Morgan Monroe State forest (MMSF) in Indiana and Harvard forest in Massachusetts. Also, above-ground biomass (AGB) was estimated for the MMSF and the Howland forest (mixed forest) in Maine. Surface reflectance and temperature, vegetation indices, soil moisture, tree height and canopy area derived from the Moderate Resolution Imagining Spectroradiometer (MODIS), the Advanced Microwave Scanning Radiometer (AMRS-E), LIDAR, and aerial imagery respectively, were used for this purpose. These variables along with others derived from remotely sensed data were used as inputs variables to process-based models which estimated GPP and ET and to a regression model which estimated AGB. The process-based models were BIOME-BGC and the Penman-Monteith equation. Measured values for the carbon and water fluxes obtained from the Eddy covariance flux tower were compared to the modeled GPP and ET. The data driven methods produced good estimation of GPP and ET with an average root mean square error (RMSE) of 0.17 molC/m2 and 0.40 mm/day, respectively for the MMSF and the Harvard forest. In addition, allometric data for the MMSF were used to develop the regression model relating AGB with stem volume. The performance of the AGB regression model was compared to site measurements using remotely sensed data for the MMSF and the Howland forest where the model AGB RMSE ranged between 2.92--3.30 Kg C/m2. Sensitivity analysis revealed that improvement in maintenance respiration estimation and remotely sensed maximum photosynthetic activity as well as accurate estimate of canopy resistance will result in improved GPP and ET predictions. Moreover, AGB estimates were

  2. Design of area array CCD image acquisition and display system based on FPGA

    Science.gov (United States)

    Li, Lei; Zhang, Ning; Li, Tianting; Pan, Yue; Dai, Yuming

    2014-09-01

    With the development of science and technology, CCD(Charge-coupled Device) has been widely applied in various fields and plays an important role in the modern sensing system, therefore researching a real-time image acquisition and display plan based on CCD device has great significance. This paper introduces an image data acquisition and display system of area array CCD based on FPGA. Several key technical challenges and problems of the system have also been analyzed and followed solutions put forward .The FPGA works as the core processing unit in the system that controls the integral time sequence .The ICX285AL area array CCD image sensor produced by SONY Corporation has been used in the system. The FPGA works to complete the driver of the area array CCD, then analog front end (AFE) processes the signal of the CCD image, including amplification, filtering, noise elimination, CDS correlation double sampling, etc. AD9945 produced by ADI Corporation to convert analog signal to digital signal. Developed Camera Link high-speed data transmission circuit, and completed the PC-end software design of the image acquisition, and realized the real-time display of images. The result through practical testing indicates that the system in the image acquisition and control is stable and reliable, and the indicators meet the actual project requirements.

  3. Status of the undisturbed mangroves at Brunei Bay, East Malaysia: a preliminary assessment based on remote sensing and ground-truth observations

    Directory of Open Access Journals (Sweden)

    Behara Satyanarayana

    2018-02-01

    Full Text Available Brunei Bay, which receives freshwater discharge from four major rivers, namely Limbang, Sundar, Weston and Menumbok, hosts a luxuriant mangrove cover in East Malaysia. However, this relatively undisturbed mangrove forest has been less scientifically explored, especially in terms of vegetation structure, ecosystem services and functioning, and land-use/cover changes. In the present study, mangrove areal extent together with species composition and distribution at the four notified estuaries was evaluated through remote sensing (Advanced Land Observation Satellite—ALOS and ground-truth (Point-Centred Quarter Method—PCQM observations. As of 2010, the total mangrove cover was found to be ca. 35,183.74 ha, of which Weston and Menumbok occupied more than two-folds (58%, followed by Sundar (27% and Limbang (15%. The medium resolution ALOS data were efficient for mapping dominant mangrove species such as Nypa fruticans, Rhizophora apiculata, Sonneratia caseolaris, S. alba and Xylocarpus granatum in the vicinity (accuracy: 80%. The PCQM estimates found a higher basal area at Limbang and Menumbok—suggestive of more mature vegetation, compared to Sundar and Weston. Mangrove stand structural complexity (derived from the complexity index was also high in the order of Limbang > Menumbok > Sundar > Weston and supporting the perspective of less/undisturbed vegetation at two former locations. Both remote sensing and ground-truth observations have complementarily represented the distribution of Sonneratia spp. as pioneer vegetation at shallow river mouths, N. fruticans in the areas of strong freshwater discharge, R. apiculata in the areas of strong neritic incursion and X. granatum at interior/elevated grounds. The results from this study would be able to serve as strong baseline data for future mangrove investigations at Brunei Bay, including for monitoring and management purposes locally at present.

  4. Status of the undisturbed mangroves at Brunei Bay, East Malaysia: a preliminary assessment based on remote sensing and ground-truth observations

    Science.gov (United States)

    Izzaty Horsali, Nurul Amira; Mat Zauki, Nurul Ashikin; Otero, Viviana; Nadzri, Muhammad Izuan; Ibrahim, Sulong; Husain, Mohd-Lokman; Dahdouh-Guebas, Farid

    2018-01-01

    Brunei Bay, which receives freshwater discharge from four major rivers, namely Limbang, Sundar, Weston and Menumbok, hosts a luxuriant mangrove cover in East Malaysia. However, this relatively undisturbed mangrove forest has been less scientifically explored, especially in terms of vegetation structure, ecosystem services and functioning, and land-use/cover changes. In the present study, mangrove areal extent together with species composition and distribution at the four notified estuaries was evaluated through remote sensing (Advanced Land Observation Satellite—ALOS) and ground-truth (Point-Centred Quarter Method—PCQM) observations. As of 2010, the total mangrove cover was found to be ca. 35,183.74 ha, of which Weston and Menumbok occupied more than two-folds (58%), followed by Sundar (27%) and Limbang (15%). The medium resolution ALOS data were efficient for mapping dominant mangrove species such as Nypa fruticans, Rhizophora apiculata, Sonneratia caseolaris, S. alba and Xylocarpus granatum in the vicinity (accuracy: 80%). The PCQM estimates found a higher basal area at Limbang and Menumbok—suggestive of more mature vegetation, compared to Sundar and Weston. Mangrove stand structural complexity (derived from the complexity index) was also high in the order of Limbang > Menumbok > Sundar > Weston and supporting the perspective of less/undisturbed vegetation at two former locations. Both remote sensing and ground-truth observations have complementarily represented the distribution of Sonneratia spp. as pioneer vegetation at shallow river mouths, N. fruticans in the areas of strong freshwater discharge, R. apiculata in the areas of strong neritic incursion and X. granatum at interior/elevated grounds. The results from this study would be able to serve as strong baseline data for future mangrove investigations at Brunei Bay, including for monitoring and management purposes locally at present. PMID:29479500

  5. Status of the undisturbed mangroves at Brunei Bay, East Malaysia: a preliminary assessment based on remote sensing and ground-truth observations.

    Science.gov (United States)

    Satyanarayana, Behara; M Muslim, Aidy; Izzaty Horsali, Nurul Amira; Mat Zauki, Nurul Ashikin; Otero, Viviana; Nadzri, Muhammad Izuan; Ibrahim, Sulong; Husain, Mohd-Lokman; Dahdouh-Guebas, Farid

    2018-01-01

    Brunei Bay, which receives freshwater discharge from four major rivers, namely Limbang, Sundar, Weston and Menumbok, hosts a luxuriant mangrove cover in East Malaysia. However, this relatively undisturbed mangrove forest has been less scientifically explored, especially in terms of vegetation structure, ecosystem services and functioning, and land-use/cover changes. In the present study, mangrove areal extent together with species composition and distribution at the four notified estuaries was evaluated through remote sensing (Advanced Land Observation Satellite-ALOS) and ground-truth (Point-Centred Quarter Method-PCQM) observations. As of 2010, the total mangrove cover was found to be ca. 35,183.74 ha, of which Weston and Menumbok occupied more than two-folds (58%), followed by Sundar (27%) and Limbang (15%). The medium resolution ALOS data were efficient for mapping dominant mangrove species such as Nypa fruticans , Rhizophora apiculata , Sonneratia caseolaris , S. alba and Xylocarpus granatum in the vicinity (accuracy: 80%). The PCQM estimates found a higher basal area at Limbang and Menumbok-suggestive of more mature vegetation, compared to Sundar and Weston. Mangrove stand structural complexity (derived from the complexity index) was also high in the order of Limbang > Menumbok > Sundar > Weston and supporting the perspective of less/undisturbed vegetation at two former locations. Both remote sensing and ground-truth observations have complementarily represented the distribution of Sonneratia spp. as pioneer vegetation at shallow river mouths, N. fruticans in the areas of strong freshwater discharge, R. apiculata in the areas of strong neritic incursion and X. granatum at interior/elevated grounds. The results from this study would be able to serve as strong baseline data for future mangrove investigations at Brunei Bay, including for monitoring and management purposes locally at present.

  6. Estimation of Hydraulic properties of a sandy soil using ground-based active and passive microwave remote sensing

    KAUST Repository

    Jonard, François

    2015-06-01

    In this paper, we experimentally analyzed the feasibility of estimating soil hydraulic properties from 1.4 GHz radiometer and 0.8-2.6 GHz ground-penetrating radar (GPR) data. Radiometer and GPR measurements were performed above a sand box, which was subjected to a series of vertical water content profiles in hydrostatic equilibrium with a water table located at different depths. A coherent radiative transfer model was used to simulate brightness temperatures measured with the radiometer. GPR data were modeled using full-wave layered medium Green\\'s functions and an intrinsic antenna representation. These forward models were inverted to optimally match the corresponding passive and active microwave data. This allowed us to reconstruct the water content profiles, and thereby estimate the sand water retention curve described using the van Genuchten model. Uncertainty of the estimated hydraulic parameters was quantified using the Bayesian-based DREAM algorithm. For both radiometer and GPR methods, the results were in close agreement with in situ time-domain reflectometry (TDR) estimates. Compared with radiometer and TDR, much smaller confidence intervals were obtained for GPR, which was attributed to its relatively large bandwidth of operation, including frequencies smaller than 1.4 GHz. These results offer valuable insights into future potential and emerging challenges in the development of joint analyses of passive and active remote sensing data to retrieve effective soil hydraulic properties.

  7. Helicopter-borne observations of the continental background aerosol in combination with remote sensing and ground-based measurements

    Science.gov (United States)

    Düsing, Sebastian; Wehner, Birgit; Seifert, Patric; Ansmann, Albert; Baars, Holger; Ditas, Florian; Henning, Silvia; Ma, Nan; Poulain, Laurent; Siebert, Holger; Wiedensohler, Alfred; Macke, Andreas

    2018-01-01

    This paper examines the representativeness of ground-based in situ measurements for the planetary boundary layer (PBL) and conducts a closure study between airborne in situ and ground-based lidar measurements up to an altitude of 2300 m. The related measurements were carried out in a field campaign within the framework of the High-Definition Clouds and Precipitation for Advancing Climate Prediction (HD(CP)2) Observational Prototype Experiment (HOPE) in September 2013 in a rural background area of central Europe.The helicopter-borne probe ACTOS (Airborne Cloud and Turbulence Observation System) provided measurements of the aerosol particle number size distribution (PNSD), the aerosol particle number concentration (PNC), the number concentration of cloud condensation nuclei (CCN-NC), and meteorological atmospheric parameters (e.g., temperature and relative humidity). These measurements were supported by the ground-based 3+2 wavelength polarization lidar system PollyXT, which provided profiles of the particle backscatter coefficient (σbsc) for three wavelengths (355, 532, and 1064 nm). Particle extinction coefficient (σext) profiles were obtained by using a fixed backscatter-to-extinction ratio (also lidar ratio, LR). A new approach was used to determine profiles of CCN-NC for continental aerosol. The results of this new approach were consistent with the airborne in situ measurements within the uncertainties.In terms of representativeness, the PNSD measurements on the ground showed a good agreement with the measurements provided with ACTOS for lower altitudes. The ground-based measurements of PNC and CCN-NC are representative of the PBL when the PBL is well mixed. Locally isolated new particle formation events on the ground or at the top of the PBL led to vertical variability in the cases presented here and ground-based measurements are not entirely representative of the PBL. Based on Mie theory (Mie, 1908), optical aerosol properties under ambient conditions for

  8. Helicopter-borne observations of the continental background aerosol in combination with remote sensing and ground-based measurements

    Directory of Open Access Journals (Sweden)

    S. Düsing

    2018-01-01

    Full Text Available This paper examines the representativeness of ground-based in situ measurements for the planetary boundary layer (PBL and conducts a closure study between airborne in situ and ground-based lidar measurements up to an altitude of 2300 m. The related measurements were carried out in a field campaign within the framework of the High-Definition Clouds and Precipitation for Advancing Climate Prediction (HD(CP2 Observational Prototype Experiment (HOPE in September 2013 in a rural background area of central Europe.The helicopter-borne probe ACTOS (Airborne Cloud and Turbulence Observation System provided measurements of the aerosol particle number size distribution (PNSD, the aerosol particle number concentration (PNC, the number concentration of cloud condensation nuclei (CCN-NC, and meteorological atmospheric parameters (e.g., temperature and relative humidity. These measurements were supported by the ground-based 3+2 wavelength polarization lidar system PollyXT, which provided profiles of the particle backscatter coefficient (σbsc for three wavelengths (355, 532, and 1064 nm. Particle extinction coefficient (σext profiles were obtained by using a fixed backscatter-to-extinction ratio (also lidar ratio, LR. A new approach was used to determine profiles of CCN-NC for continental aerosol. The results of this new approach were consistent with the airborne in situ measurements within the uncertainties.In terms of representativeness, the PNSD measurements on the ground showed a good agreement with the measurements provided with ACTOS for lower altitudes. The ground-based measurements of PNC and CCN-NC are representative of the PBL when the PBL is well mixed. Locally isolated new particle formation events on the ground or at the top of the PBL led to vertical variability in the cases presented here and ground-based measurements are not entirely representative of the PBL. Based on Mie theory (Mie, 1908, optical aerosol properties under ambient

  9. First observations of tropospheric δD data observed by ground- and space-based remote sensing and surface in-situ measurement techniques at MUSICA's principle reference station (Izaña Observatory, Spain)

    Science.gov (United States)

    González, Yenny; Schneider, Matthias; Christner, Emanuel; Rodríguez, Omaira E.; Sepúlveda, Eliezer; Dyroff, Christoph; Wiegele, Andreas

    2013-04-01

    The main goal of the project MUSICA (Multiplatform remote Sensing of Isotopologues for investigating the Cycle of Atmospheric water) is the generation of a quasi global tropospheric water vapor isototopologue dataset of a good and well-documented quality. Therefore, new ground- and space-based remote sensing observations (NDACC-FTIR and IASI/METOP) are combined with in-situ measurements. This work presents the first comparison between in-situ and remote sensing observations made at the Izaña Atmospheric Research Centre (Tenerife, Canary Islands, Spain). The in-situ measurements are made by a Picarro L2120-i water vapor isotopologue analyzer. At Izaña the in-situ data are affected by local small-scale mixing processes: during daylight, the thermally buoyant upslope flow prompts the mixing between the Marine Boundary Layer (MBL) and the low Free Troposphere (FT). However, the remote sensors detect δD values averaged over altitudes that are more representative for the free troposphere. This difference has to be considered for the comparison. In general, a good agreement between the MUSICA remote sensing and the in situ H2O-versus-δD plots is found, which demonstrates that the MUSICA δD remote sensing products add scientifically valuable information to the H2O data.

  10. The ground based plan

    International Nuclear Information System (INIS)

    1989-01-01

    The paper presents a report of ''The Ground Based Plan'' of the United Kingdom Science and Engineering Research Council. The ground based plan is a plan for research in astronomy and planetary science by ground based techniques. The contents of the report contains a description of:- the scientific objectives and technical requirements (the basis for the Plan), the present organisation and funding for the ground based programme, the Plan, the main scientific features and the further objectives of the Plan. (U.K.)

  11. Ergonomic problems regarding the interactive touch input via screens in onboard and ground-based flight control

    Science.gov (United States)

    Holzhausen, K. P.; Gaertner, K. P.

    1985-01-01

    A significant problem concerning the integration of display and switching functions is related to the fact that numerous informative data which have to be processed by man must be read from only a few display devices. A satisfactory ergonomic design of integrated display devices and keyboards is in many cases difficult, because not all functions which can be displayed and selected are simultaneously available. A technical solution which provides an integration of display and functional elements on the basis of the highest flexibility is obtained by using a cathode ray tube with a touch-sensitive screen. The employment of an integrated data input/output system is demonstrated for the cases of onboard and ground-based flight control. Ergonomic studies conducted to investigate the suitability of an employment of touch-sensitive screens are also discussed.

  12. Non-Colocated Kinesthetic Display Limits Compliance Discrimination in the Absence of Terminal Force Cues.

    Science.gov (United States)

    Brown, Jeremy D; Shelley, Mackenzie K; Gardner, Duane; Gansallo, Emmanuel A; Gillespie, R Brent

    2016-01-01

    An important goal of haptic display is to make available the action/reaction relationships that define interactions between the body and the physical world. While in physical world interactions reaction cues invariably impinge on the same part of the body involved in action (reaction and action are colocated), a haptic interface is quite capable of rendering feedback to a separate body part than that used for producing exploratory actions (non-colocated action and reaction). This most commonly occurs with the use of vibrotactile display, in which a cutaneous cue has been substituted for a kinesthetic cue (a kind of sensory substitution). In this paper, we investigate whether non-colocated force and displacement cues degrade the perception of compliance. Using a custom non-colocated kinesthetic display in which one hand controls displacement and the other senses force, we ask participants to discriminate between two virtual springs with matched terminal force and adjustable non-linearity. An additional condition includes one hand controlling displacement while the other senses force encoded in a vibrotactile cue. Results show that when the terminal force cue is unavailable, and even when sensory substitution is not involved, non-colocated kinesthetic displays degrade compliance discrimination relative to colocated kinesthetic displays. Compliance discrimination is also degraded with vibrotactile display of force. These findings suggest that non-colocated kinesthetic displays and, likewise, cutaneous sensory substitution displays should be avoided when discrimination of compliance is necessary for task success.

  13. Spatiotemporal Diffusive Evolution and Fractal Structure of Ground Motion

    Science.gov (United States)

    Suwada, Tsuyoshi

    2018-02-01

    The spatiotemporal diffusive evolution and fractal structure of ground motion have been investigated at the in-ground tunnel of the KEK B-Factory (KEKB) injector linear accelerator (linac). The slow dynamic fluctuating displacements of the tunnel floor are measured in real time with a new remote-controllable sensing system based on a laser-based alignment system. Based on spatiotemporal analyses with linear-regression models, which were applied in both the time and frequency domains to time-series data recorded over a period of approximately 8 months, both coherent and stochastic components in the displacements of the tunnel floor were clearly observed along the entire length of the linac. In particular, it was clearly observed that the stochastic components exhibited characteristic spatiotemporal diffusive evolution with the fractal structure and fractional dimension. This report describes in detail the experimental techniques and analyses of the spatiotemporal diffusive evolution of ground motion observed at the in-ground tunnel of the injector linac using a real-time remote-controllable sensing system.

  14. A Hybrid Architecture for Vision-Based Obstacle Avoidance

    Directory of Open Access Journals (Sweden)

    Mehmet Serdar Güzel

    2013-01-01

    Full Text Available This paper proposes a new obstacle avoidance method using a single monocular vision camera as the only sensor which is called as Hybrid Architecture. This architecture integrates a high performance appearance-based obstacle detection method into an optical flow-based navigation system. The hybrid architecture was designed and implemented to run both methods simultaneously and is able to combine the results of each method using a novel arbitration mechanism. The proposed strategy successfully fused two different vision-based obstacle avoidance methods using this arbitration mechanism in order to permit a safer obstacle avoidance system. Accordingly, to establish the adequacy of the design of the obstacle avoidance system, a series of experiments were conducted. The results demonstrate the characteristics of the proposed architecture, and the results prove that its performance is somewhat better than the conventional optical flow-based architecture. Especially, the robot employing Hybrid Architecture avoids lateral obstacles in a more smooth and robust manner than when using the conventional optical flow-based technique.

  15. Displaying Sensed Tactile Cues with a Fingertip Haptic Device.

    Science.gov (United States)

    Pacchierotti, Claudio; Prattichizzo, Domenico; Kuchenbecker, Katherine J

    2015-01-01

    Telerobotic systems enable humans to explore and manipulate remote environments for applications such as surgery and disaster response, but few such systems provide the operator with cutaneous feedback. This article presents a novel approach to remote cutaneous interaction; our method is compatible with any fingertip tactile sensor and any mechanical tactile display device, and it does not require a position/force or skin deformation model. Instead, it directly maps the sensed stimuli to the best possible input commands for the device's motors using a data set recorded with the tactile sensor inside the device. As a proof of concept, we considered a haptic system composed of a BioTac tactile sensor, in charge of measuring contact deformations, and a custom 3-DoF cutaneous device with a flat contact platform, in charge of applying deformations to the user's fingertip. To validate the proposed approach and discover its inherent tradeoffs, we carried out two remote tactile interaction experiments. The first one evaluated the error between the tactile sensations registered by the BioTac in a remote environment and the sensations created by the cutaneous device for six representative tactile interactions and 27 variations of the display algorithm. The normalized average errors in the best condition were 3.0 percent of the BioTac's full 12-bit scale. The second experiment evaluated human subjects' experiences for the same six remote interactions and eight algorithm variations. The average subjective rating for the best algorithm variation was 8.2 out of 10, where 10 is best.

  16. Using Distance Sensors to Perform Collision Avoidance Maneuvres on Uav Applications

    Science.gov (United States)

    Raimundo, A.; Peres, D.; Santos, N.; Sebastião, P.; Souto, N.

    2017-08-01

    The Unmanned Aerial Vehicles (UAV) and its applications are growing for both civilian and military purposes. The operability of an UAV proved that some tasks and operations can be done easily and at a good cost-efficiency ratio. Nowadays, an UAV can perform autonomous missions. It is very useful to certain UAV applications, such as meteorology, vigilance systems, agriculture, environment mapping and search and rescue operations. One of the biggest problems that an UAV faces is the possibility of collision with other objects in the flight area. To avoid this, an algorithm was developed and implemented in order to prevent UAV collision with other objects. "Sense and Avoid" algorithm was developed as a system for UAVs to avoid objects in collision course. This algorithm uses a Light Detection and Ranging (LiDAR), to detect objects facing the UAV in mid-flights. This light sensor is connected to an on-board hardware, Pixhawk's flight controller, which interfaces its communications with another hardware: Raspberry Pi. Communications between Ground Control Station and UAV are made via Wi-Fi or cellular third or fourth generation (3G/4G). Some tests were made in order to evaluate the "Sense and Avoid" algorithm's overall performance. These tests were done in two different environments: A 3D simulated environment and a real outdoor environment. Both modes worked successfully on a simulated 3D environment, and "Brake" mode on a real outdoor, proving its concepts.

  17. Paper-based electrochemical sensing platform with integral battery and electrochromic read-out.

    Science.gov (United States)

    Liu, Hong; Crooks, Richard M

    2012-03-06

    We report a battery-powered, microelectrochemical sensing platform that reports its output using an electrochromic display. The platform is fabricated based on paper fluidics and uses a Prussian blue spot electrodeposited on an indium-doped tin oxide thin film as the electrochromic indicator. The integrated metal/air battery powers both the electrochemical sensor and the electrochromic read-out, which are in electrical contact via a paper reservoir. The sample activates the battery and the presence of analyte in the sample initiates the color change of the Prussian blue spot. The entire system is assembled on the lab bench, without the need for cleanroom facilities. The applicability of the device to point-of-care sensing is demonstrated by qualitative detection of 0.1 mM glucose and H(2)O(2) in artificial urine samples.

  18. A fiber Bragg grating acceleration sensor for ground surveillance

    Science.gov (United States)

    Jiang, Shaodong; Zhang, Faxiang; Lv, Jingsheng; Ni, Jiasheng; Wang, Chang

    2017-10-01

    Ground surveillance system is a kind of intelligent monitoring equipment for detecting and tracking the ground target. This paper presents a fiber Bragg grating (FBG) acceleration sensor for ground surveillance, which has the characteristics of no power supply, anti-electromagnetic interference, easy large-scale networking, and small size. Which make it able to achieve the advantage of the ground surveillance system while avoiding the shortcoming of the electric sensing. The sensor has a double cantilever beam structure with a sensitivity of 1000 pm/g. Field experiment has been carried out on a flood beach to examine the sensor performance. The result shows that the detection distance on the walking of personnel reaches 70m, and the detection distance on the ordinary motor vehicle reaches 200m. The performance of the FBG sensor can satisfy the actual needs of the ground surveillance system.

  19. Municipality Level Simulations of Dengue Fever Incidence in Puerto Rico Using Ground Based and Remotely Sensed Climate Data

    Science.gov (United States)

    Quattrochi, Dale A.; Morin, Cory

    2015-01-01

    Dengue fever (DF) is caused by a virus transmitted between humans and Aedes genus mosquitoes through blood feeding. In recent decades incidence of the disease has drastically increased in the tropical Americas, culminating with the Pan American outbreak in 2010 which resulted in 1.7 million reported cases. In Puerto Rico dengue is endemic, however, there is significant inter-annual, intraannual, and spatial variability in case loads. Variability in climate and the environment, herd immunity and virus genetics, and demographic characteristics may all contribute to differing patterns of transmission both spatially and temporally. Knowledge of climate influences on dengue incidence could facilitate development of early warning systems allowing public health workers to implement appropriate transmission intervention strategies. In this study, we simulate dengue incidence in several municipalities in Puerto Rico using population and meteorological data derived from ground based stations and remote sensing instruments. This data was used to drive a process based model of vector population development and virus transmission. Model parameter values for container composition, vector characteristics, and incubation period were chosen by employing a Monte Carlo approach. Multiple simulations were performed for each municipality and the results were compared with reported dengue cases. The best performing simulations were retained and their parameter values and meteorological input were compared between years and municipalities. Parameter values varied by municipality and year illustrating the complexity and sensitivity of the disease system. Local characteristics including the natural and built environment impact transmission dynamics and produce varying responses to meteorological conditions.

  20. Comprehensive long distance and real-time pipeline monitoring system based on fiber optic sensing

    Energy Technology Data Exchange (ETDEWEB)

    Nikles, Marc; Ravet, Fabien; Briffod, Fabien [Omnisens S.A., Morges (Switzerland)

    2009-07-01

    An increasing number of pipelines are constructed in remote regions affected by harsh environmental conditions. These pipeline routes often cross mountain areas which are characterized by unstable grounds and where soil texture changes between winter and summer increase the probability of hazards. Due to the long distances to be monitored and the linear nature of pipelines, distributed fiber optic sensing techniques offer significant advantages and the capability to detect and localize pipeline disturbance with great precision. Furthermore pipeline owner/operators lay fiber optic cable parallel to transmission pipelines for telecommunication purposes and at minimum additional cost monitoring capabilities can be added to the communication system. The Brillouin-based Omnisens DITEST monitoring system has been used in several long distance pipeline projects. The technique is capable of measuring strain and temperature over 100's kilometers with meter spatial resolution. Dedicated fiber optic cables have been developed for continuous strain and temperature monitoring and their deployment along the pipeline has enabled permanent and continuous pipeline ground movement, intrusion and leak detection. This paper presents a description of the fiber optic Brillouin-based DITEST sensing technique, its measurement performance and limits, while addressing future perspectives for pipeline monitoring. (author)

  1. Determining spatio-temporal distribution of bee forage species of Al-Baha region based on ground inventorying supported with GIS applications and Remote Sensed Satellite Image analysis

    Directory of Open Access Journals (Sweden)

    Nuru Adgaba

    2017-07-01

    Full Text Available In arid zones, the shortage of bee forage is critical and usually compels beekeepers to move their colonies in search of better forages. Identifying and mapping the spatiotemporal distribution of the bee forages over given area is important for better management of bee colonies. In this study honey bee plants in the target areas were inventoried following, ground inventory work supported with GIS applications. The study was conducted on 85 large plots of 50 × 50 m each. At each plot, data on species name, height, base diameter, crown height, crown diameter has been taken for each plant with their respective geographical positions. The data were stored, and processed using Trimble GPS supported with ArcGIS10 software program. The data were used to estimate the relative frequency, density, abundance and species diversity, species important value index and apicultural value of the species. In addition, Remotely Sensed Satellite Image of the area was obtained and processed using Hopfield Artificial Neural Network techniques. During the study, 182 species from 49 plant families were identified as bee forages of the target area. From the total number of species; shrubs, herbs and trees were accounting for 61%, 27.67%, and 11.53% respectively. Of which Ziziphus spina-christi, Acacia tortilis, Acacia origina, Acacia asak, Lavandula dentata, and Hypoestes forskaolii were the major nectar source plants of the area in their degree of importance. The average vegetation cover values of the study areas were low (<30% with low Shannon’s species diversity indices (H′ of 0.5–1.52 for different sites. Based on the eco-climatological factors and the variations in their flowering period, these major bee forage species were found to form eight distinct spatiotemporal categories which allow beekeepers to migrate their colonies to exploit the resources at different seasons and place. The Remote Sensed Satellite Image analysis confirmed the spatial

  2. "Slow-scanning" in Ground-based Mid-infrared Observations

    Science.gov (United States)

    Ohsawa, Ryou; Sako, Shigeyuki; Miyata, Takashi; Kamizuka, Takafumi; Okada, Kazushi; Mori, Kiyoshi; Uchiyama, Masahito S.; Yamaguchi, Junpei; Fujiyoshi, Takuya; Morii, Mikio; Ikeda, Shiro

    2018-04-01

    Chopping observations with a tip-tilt secondary mirror have conventionally been used in ground-based mid-infrared observations. However, it is not practical for next generation large telescopes to have a large tip-tilt mirror that moves at a frequency larger than a few hertz. We propose an alternative observing method, a "slow-scanning" observation. Images are continuously captured as movie data, while the field of view is slowly moved. The signal from an astronomical object is extracted from the movie data by a low-rank and sparse matrix decomposition. The performance of the "slow-scanning" observation was tested in an experimental observation with Subaru/COMICS. The quality of a resultant image in the "slow-scanning" observation was as good as in a conventional chopping observation with COMICS, at least for a bright point-source object. The observational efficiency in the "slow-scanning" observation was better than that in the chopping observation. The results suggest that the "slow-scanning" observation can be a competitive method for the Subaru telescope and be of potential interest to other ground-based facilities to avoid chopping.

  3. Corn and sorghum phenotyping using a fixed-wing UAV-based remote sensing system

    Science.gov (United States)

    Shi, Yeyin; Murray, Seth C.; Rooney, William L.; Valasek, John; Olsenholler, Jeff; Pugh, N. Ace; Henrickson, James; Bowden, Ezekiel; Zhang, Dongyan; Thomasson, J. Alex

    2016-05-01

    Recent development of unmanned aerial systems has created opportunities in automation of field-based high-throughput phenotyping by lowering flight operational cost and complexity and allowing flexible re-visit time and higher image resolution than satellite or manned airborne remote sensing. In this study, flights were conducted over corn and sorghum breeding trials in College Station, Texas, with a fixed-wing unmanned aerial vehicle (UAV) carrying two multispectral cameras and a high-resolution digital camera. The objectives were to establish the workflow and investigate the ability of UAV-based remote sensing for automating data collection of plant traits to develop genetic and physiological models. Most important among these traits were plant height and number of plants which are currently manually collected with high labor costs. Vegetation indices were calculated for each breeding cultivar from mosaicked and radiometrically calibrated multi-band imagery in order to be correlated with ground-measured plant heights, populations and yield across high genetic-diversity breeding cultivars. Growth curves were profiled with the aerial measured time-series height and vegetation index data. The next step of this study will be to investigate the correlations between aerial measurements and ground truth measured manually in field and from lab tests.

  4. See-and-Avoid Collision Avoidance Using ADS-B Signal and Radar Sensing, Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — IAI proposes an innovative collision avoidance radar and communication technology to detect and track both cooperative and non-cooperative targets. The system...

  5. CO Seasonal Variability and Trend over Paris Megacity Using Ground-Based QualAir FTS and Satellite IASI-MetOp Measurements

    Science.gov (United States)

    Te, Yao; Jeseck, Pascal; Hadji-Lazaro, Juliette

    2012-11-01

    In a growing world with more than 7 billion inhabitants and big emerging countries such as China, Brazil and India, emissions of anthropogenic pollutants are increasing continuously. Monitoring and control of atmospheric pollutants in megacities have become a major challenge for scientists and public health authorities in environmental research area. The QualAir platform at University Pierre et Marie Curie (UPMC), is an innovating experimental research platform dedicated to survey urban atmospheric pollution and air quality. A Bruker Optics IFS 125HR Fourier transform spectrometer belonged to the Laboratoire de Physique Moléculaire pour l'Atmosphère et l'Astrophysique (LPMAA), was adapted for ground-based atmospheric measurements. As one of the major instruments of the QualAir platform, this ground-based Fourier transform spectrometer (QualAir FTS) analyses the composition of the urban atmosphere of Paris, which is the third largest European megacity. The continuous monitoring of atmospheric pollutants is essential to improve the understanding of urban air pollution processes. Associated with a sun-tracker, the QualAir remote sensing FTS operates in solar infrared absorption and enables to monitor many trace gases, and to follow up their variability in the Ile-de-France region. Concentrations of atmospheric pollutants are retrieved by the radiative transfer model PROFFIT. These ground-based remote sensing measurements are compared to ground in-situ measurements and to satellite data from IASI-MetOp (Infrared Atmospheric Sounding Interferometer). The remote sensing total column of the carbon monoxide (CO) obtained from January 2009 to June 2012, has a seasonal variability with a maximum in April and a minimum in October. While, after 2008, the mean CO level is quite stable (no significant decrease as before 2008).

  6. A Near-Term Concept for Trajectory Based Operations with Air/Ground Data Link Communication

    Science.gov (United States)

    McNally, David; Mueller, Eric; Thipphavong, David; Paielli, Russell; Cheng, Jinn-Hwei; Lee, Chuhan; Sahlman, Scott; Walton, Joe

    2010-01-01

    An operating concept and required system components for trajectory-based operations with air/ground data link for today's en route and transition airspace is proposed. Controllers are fully responsible for separation as they are today, and no new aircraft equipage is required. Trajectory automation computes integrated solutions to problems like metering, weather avoidance, traffic conflicts and the desire to find and fly more time/fuel efficient flight trajectories. A common ground-based system supports all levels of aircraft equipage and performance including those equipped and not equipped for data link. User interface functions for the radar controller's display make trajectory-based clearance advisories easy to visualize, modify if necessary, and implement. Laboratory simulations (without human operators) were conducted to test integrated operation of selected system components with uncertainty modeling. Results are based on 102 hours of Fort Worth Center traffic recordings involving over 37,000 individual flights. The presence of uncertainty had a marginal effect (5%) on minimum-delay conflict resolution performance, and windfavorable routes had no effect on detection and resolution metrics. Flight plan amendments and clearances were substantially reduced compared to today s operations. Top-of-descent prediction errors are the largest cause of failure indicating that better descent predictions are needed to reliably achieve fuel-efficient descent profiles in medium to heavy traffic. Improved conflict detections for climbing flights could enable substantially more continuous climbs to cruise altitude. Unlike today s Conflict Alert, tactical automation must alert when an altitude amendment is entered, but before the aircraft starts the maneuver. In every other failure case tactical automation prevented losses of separation. A real-time prototype trajectory trajectory-automation system is running now and could be made ready for operational testing at an en route

  7. Cross-validation Methodology between Ground and GPM Satellite-based Radar Rainfall Product over Dallas-Fort Worth (DFW) Metroplex

    Science.gov (United States)

    Chen, H.; Chandrasekar, V.; Biswas, S.

    2015-12-01

    Over the past two decades, a large number of rainfall products have been developed based on satellite, radar, and/or rain gauge observations. However, to produce optimal rainfall estimation for a given region is still challenging due to the space time variability of rainfall at many scales and the spatial and temporal sampling difference of different rainfall instruments. In order to produce high-resolution rainfall products for urban flash flood applications and improve the weather sensing capability in urban environment, the center for Collaborative Adaptive Sensing of the Atmosphere (CASA), in collaboration with National Weather Service (NWS) and North Central Texas Council of Governments (NCTCOG), has developed an urban radar remote sensing network in DFW Metroplex. DFW is the largest inland metropolitan area in the U.S., that experiences a wide range of natural weather hazards such as flash flood and hailstorms. The DFW urban remote sensing network, centered by the deployment of eight dual-polarization X-band radars and a NWS WSR-88DP radar, is expected to provide impacts-based warning and forecasts for benefit of the public safety and economy. High-resolution quantitative precipitation estimation (QPE) is one of the major goals of the development of this urban test bed. In addition to ground radar-based rainfall estimation, satellite-based rainfall products for this area are also of interest for this study. Typical example is the rainfall rate product produced by the Dual-frequency Precipitation Radar (DPR) onboard Global Precipitation Measurement (GPM) Core Observatory satellite. Therefore, cross-comparison between ground and space-based rainfall estimation is critical to building an optimal regional rainfall system, which can take advantages of the sampling differences of different sensors. This paper presents the real-time high-resolution QPE system developed for DFW urban radar network, which is based upon the combination of S-band WSR-88DP and X

  8. Effects of heat stress and probiotic supplementation on protein functionality and oxidative stability of ground chicken leg meat during display storage

    Science.gov (United States)

    The objective of this study was to evaluate effects of heat stress and probiotic supplementation on protein functionality and oxidative stability of ground chicken leg meat during display storage. Two hundred and forty 1-day-old male chicks (5 bird per pen) were randomly subjected to four treatments...

  9. Satellite and ground-based remote sensing of aerosols during intense haze event of October 2013 over lahore, Pakistan

    Science.gov (United States)

    Tariq, Salman; Zia, ul-Haq; Ali, Muhammad

    2016-02-01

    Due to increase in population and economic development, the mega-cities are facing increased haze events which are causing important effects on the regional environment and climate. In order to understand these effects, we require an in-depth knowledge of optical and physical properties of aerosols in intense haze conditions. In this paper an effort has been made to analyze the microphysical and optical properties of aerosols during intense haze event over mega-city of Lahore by using remote sensing data obtained from satellites (Terra/Aqua Moderate-resolution Imaging Spectroradiometer (MODIS) and Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation (CALIPSO)) and ground based instrument (AErosol RObotic NETwork (AERONET)) during 6-14 October 2013. The instantaneous highest value of Aerosol Optical Depth (AOD) is observed to be 3.70 on 9 October 2013 followed by 3.12 on 8 October 2013. The primary cause of such high values is large scale crop residue burning and urban-industrial emissions in the study region. AERONET observations show daily mean AOD of 2.36 which is eight times higher than the observed values on normal day. The observed fine mode volume concentration is more than 1.5 times greater than the coarse mode volume concentration on the high aerosol burden day. We also find high values (~0.95) of Single Scattering Albedo (SSA) on 9 October 2013. Scatter-plot between AOD (500 nm) and Angstrom exponent (440-870 nm) reveals that biomass burning/urban-industrial aerosols are the dominant aerosol type on the heavy aerosol loading day over Lahore. MODIS fire activity image suggests that the areas in the southeast of Lahore across the border with India are dominated by biomass burning activities. A Hybrid Single-Particle Lagrangian Integrated Trajectory (HYSPLIT) model backward trajectory showed that the winds at 1000 m above the ground are responsible for transport from southeast region of biomass burning to Lahore. CALIPSO derived sub-types of

  10. Ground Albedo Neutron Sensing (GANS) method for measurements of soil moisture in cropped fields

    Science.gov (United States)

    Andres Rivera Villarreyes, Carlos; Baroni, Gabriele; Oswald, Sascha E.

    2013-04-01

    Measurement of soil moisture at the plot or hill-slope scale is an important link between local vadose zone hydrology and catchment hydrology. However, so far only few methods are on the way to close this gap between point measurements and remote sensing. This study evaluates the applicability of the Ground Albedo Neutron Sensing (GANS) for integral quantification of seasonal soil moisture in the root zone at the scale of a field or small watershed, making use of the crucial role of hydrogen as neutron moderator relative to other landscape materials. GANS measurements were performed at two locations in Germany under different vegetative situations and seasonal conditions. Ground albedo neutrons were measured at (i) a lowland Bornim farmland (Brandenburg) cropped with sunflower in 2011 and winter rye in 2012, and (ii) a mountainous farmland catchment (Schaefertal, Harz Mountains) since middle 2011. At both sites depth profiles of soil moisture were measured at several locations in parallel by frequency domain reflectometry (FDR) for comparison and calibration. Initially, calibration parameters derived from a previous study with corn cover were tested under sunflower and winter rye periods at the same farmland. GANS soil moisture based on these parameters showed a large discrepancy compared to classical soil moisture measurements. Therefore, two new calibration approaches and four different ways of integration the soil moisture profile to an integral value for GANS were evaluated in this study. This included different sets of calibration parameters based on different growing periods of sunflower. New calibration parameters showed a good agreement with FDR network during sunflower period (RMSE = 0.023 m3 m-3), but they underestimated soil moisture in the winter rye period. The GANS approach resulted to be highly affected by temporal changes of biomass and crop types which suggest the need of neutron corrections for long-term observations with crop rotation. Finally

  11. Experience with model based display for advanced diagnostics and control

    International Nuclear Information System (INIS)

    Staffon, J.D.; Lindsay, R.W.

    1989-01-01

    A full color, model based display system based on the Rankine thermodynamic cycle has been developed for use at the Experimental Breeder Reactor II by plant operators, engineers, and experimenters. The displays generate a real time thermodynamic model of the plant processes on computer screens to provide a direct indication of the plant performance. Operators and others who view the displays are no longer required to mentally ''construct'' a model of the process before acting. The model based display accurately depicts the plant states. It appears to effectively reduce the gulf of evaluation, which should result in a significant reduction in human operator errors if this plant display approach is adopted by the nuclear industry. Preliminary comments from users, including operators, indicate an overwhelming acceptance of the display approach. The displays incorporate alarm functions as well as levels of detail ''paging'' capability. The system is developed on a computer network which allows the easy addition of displays as well as extra computers. Constructing a complete console can be rapid and inexpensive. 1 ref., 2 figs

  12. Ground-and satellite-based evidence of the biophysical mechanisms behind the greening Sahel

    DEFF Research Database (Denmark)

    Brandt, Martin Stefan; Mbow, Cheikh; Diouf, Abdoul A.

    2015-01-01

    After a dry period with prolonged droughts in the 1970s and 1980s, recent scientific outcome suggests that the decades of abnormally dry conditions in the Sahel have been reversed by positive anomalies in rainfall. Various remote sensing studies observed a positive trend in vegetation greenness...... over the last decades which is known as the re-greening of the Sahel. However, little investment has been made in including long-term ground-based data collections to evaluate and better understand the biophysical mechanisms behind these findings. Thus, deductions on a possible increment in biomass...... remain speculative. Our aim is to bridge these gaps and give specifics on the biophysical background factors of the re-greening Sahel. Therefore, a trend analysis was applied on long time series (1987-2013) of satellite-based vegetation and rainfall data, as well as on ground-observations of leaf biomass...

  13. Real-Time and High-Fidelity Simulation Environment for Autonomous Ground Vehicle Dynamics

    Science.gov (United States)

    Cameron, Jonathan; Myint, Steven; Kuo, Calvin; Jain, Abhi; Grip, Havard; Jayakumar, Paramsothy; Overholt, Jim

    2013-01-01

    This paper reports on a collaborative project between U.S. Army TARDEC and Jet Propulsion Laboratory (JPL) to develop a unmanned ground vehicle (UGV) simulation model using the ROAMS vehicle modeling framework. Besides modeling the physical suspension of the vehicle, the sensing and navigation of the HMMWV vehicle are simulated. Using models of urban and off-road environments, the HMMWV simulation was tested in several ways, including navigation in an urban environment with obstacle avoidance and the performance of a lane change maneuver.

  14. Consortium for military LCD display procurement

    Science.gov (United States)

    Echols, Gregg

    2002-08-01

    International Display Consortium (IDC) is the joining together of display companies to combined their buying power and obtained favorable terms with a major LCD manufacturer. Consolidating the buying power and grouping the demand enables the rugged display industry of avionics, ground vehicles, and ship based display manufacturers to have unencumbered access to high performance AMLCDs while greatly reducing risk and lowering cost. With an unrestricted supply of AMLCD displays, the consortium members have total control of their risk, cost, deliveries and added value partners. Every display manufacturer desires a very close relationship with a display vender. With IDC each consortium member achieves a close relationship. Consortium members enjoy cost effective access to high performance, industry standard sized LCD panels, and modified commercial displays with 100 degree C clearing points and portrait configurations. Consortium members also enjoy proposal support, technical support and long-term support.

  15. Noninvasive Remote Sensing Techniques for Infrastructures Diagnostics

    Directory of Open Access Journals (Sweden)

    Angelo Palombo

    2011-01-01

    Full Text Available The present paper aims at analyzing the potentialities of noninvasive remote sensing techniques used for detecting the conservation status of infrastructures. The applied remote sensing techniques are ground-based microwave radar interferometer and InfraRed Thermography (IRT to study a particular structure planned and made in the framework of the ISTIMES project (funded by the European Commission in the frame of a joint Call “ICT and Security” of the Seventh Framework Programme. To exploit the effectiveness of the high-resolution remote sensing techniques applied we will use the high-frequency thermal camera to measure the structures oscillations by high-frequency analysis and ground-based microwave radar interferometer to measure the dynamic displacement of several points belonging to a large structure. The paper describes the preliminary research results and discusses on the future applicability and techniques developments for integrating high-frequency time series data of the thermal imagery and ground-based microwave radar interferometer data.

  16. Sense of presence and anxiety during virtual social interactions between a human and virtual humans.

    Science.gov (United States)

    Morina, Nexhmedin; Brinkman, Willem-Paul; Hartanto, Dwi; Emmelkamp, Paul M G

    2014-01-01

    Virtual reality exposure therapy (VRET) has been shown to be effective in treatment of anxiety disorders. Yet, there is lack of research on the extent to which interaction between the individual and virtual humans can be successfully implanted to increase levels of anxiety for therapeutic purposes. This proof-of-concept pilot study aimed at examining levels of the sense of presence and anxiety during exposure to virtual environments involving social interaction with virtual humans and using different virtual reality displays. A non-clinical sample of 38 participants was randomly assigned to either a head-mounted display (HMD) with motion tracker and sterescopic view condition or a one-screen projection-based virtual reality display condition. Participants in both conditions engaged in free speech dialogues with virtual humans controlled by research assistants. It was hypothesized that exposure to virtual social interactions will elicit moderate levels of sense of presence and anxiety in both groups. Further it was expected that participants in the HMD condition will report higher scores of sense of presence and anxiety than participants in the one-screen projection-based display condition. Results revealed that in both conditions virtual social interactions were associated with moderate levels of sense of presence and anxiety. Additionally, participants in the HMD condition reported significantly higher levels of presence than those in the one-screen projection-based display condition (p = .001). However, contrary to the expectations neither the average level of anxiety nor the highest level of anxiety during exposure to social virtual environments differed between the groups (p = .97 and p = .75, respectively). The findings suggest that virtual social interactions can be successfully applied in VRET to enhance sense of presence and anxiety. Furthermore, our results indicate that one-screen projection-based displays can successfully activate levels of anxiety in

  17. Sense of presence and anxiety during virtual social interactions between a human and virtual humans

    Directory of Open Access Journals (Sweden)

    Nexhmedin Morina

    2014-04-01

    Full Text Available Virtual reality exposure therapy (VRET has been shown to be effective in treatment of anxiety disorders. Yet, there is lack of research on the extent to which interaction between the individual and virtual humans can be successfully implanted to increase levels of anxiety for therapeutic purposes. This proof-of-concept pilot study aimed at examining levels of the sense of presence and anxiety during exposure to virtual environments involving social interaction with virtual humans and using different virtual reality displays. A non-clinical sample of 38 participants was randomly assigned to either a head-mounted display (HMD with motion tracker and sterescopic view condition or a one-screen projection-based virtual reality display condition. Participants in both conditions engaged in free speech dialogues with virtual humans controlled by research assistants. It was hypothesized that exposure to virtual social interactions will elicit moderate levels of sense of presence and anxiety in both groups. Further it was expected that participants in the HMD condition will report higher scores of sense of presence and anxiety than participants in the one-screen projection-based display condition. Results revealed that in both conditions virtual social interactions were associated with moderate levels of sense of presence and anxiety. Additionally, participants in the HMD condition reported significantly higher levels of presence than those in the one-screen projection-based display condition (p = .001. However, contrary to the expectations neither the average level of anxiety nor the highest level of anxiety during exposure to social virtual environments differed between the groups (p = .97 and p = .75, respectively. The findings suggest that virtual social interactions can be successfully applied in VRET to enhance sense of presence and anxiety. Furthermore, our results indicate that one-screen projection-based displays can successfully activate levels

  18. Predictive modeling of hazardous waste landfill total above-ground biomass using passive optical and LIDAR remotely sensed data

    Science.gov (United States)

    Hadley, Brian Christopher

    This dissertation assessed remotely sensed data and geospatial modeling technique(s) to map the spatial distribution of total above-ground biomass present on the surface of the Savannah River National Laboratory's (SRNL) Mixed Waste Management Facility (MWMF) hazardous waste landfill. Ordinary least squares (OLS) regression, regression kriging, and tree-structured regression were employed to model the empirical relationship between in-situ measured Bahia (Paspalum notatum Flugge) and Centipede [Eremochloa ophiuroides (Munro) Hack.] grass biomass against an assortment of explanatory variables extracted from fine spatial resolution passive optical and LIDAR remotely sensed data. Explanatory variables included: (1) discrete channels of visible, near-infrared (NIR), and short-wave infrared (SWIR) reflectance, (2) spectral vegetation indices (SVI), (3) spectral mixture analysis (SMA) modeled fractions, (4) narrow-band derivative-based vegetation indices, and (5) LIDAR derived topographic variables (i.e. elevation, slope, and aspect). Results showed that a linear combination of the first- (1DZ_DGVI), second- (2DZ_DGVI), and third-derivative of green vegetation indices (3DZ_DGVI) calculated from hyperspectral data recorded over the 400--960 nm wavelengths of the electromagnetic spectrum explained the largest percentage of statistical variation (R2 = 0.5184) in the total above-ground biomass measurements. In general, the topographic variables did not correlate well with the MWMF biomass data, accounting for less than five percent of the statistical variation. It was concluded that tree-structured regression represented the optimum geospatial modeling technique due to a combination of model performance and efficiency/flexibility factors.

  19. Overview of Ground Air Quality Measurements and Their Links to Airborne, Remote Sensing and Model Studies during the KORUS-AQ Campaign

    Science.gov (United States)

    Lee, G.; Ahn, J. Y.; Chang, L. S.; Kim, J.; Park, R.

    2017-12-01

    During the KORUS-AQ, extensive sets of chemical measurements for reactive gases and aerosol species were made at 3 major sites on upwind island (Baengyeong Island), urban (Olympic Park in Seoul) and downwind rural forest location (Taewha Forest). Also, intensive aerosol size and composition observations from 5 NIER super sites, 3 NIMR monitoring sites, and 5 other university sites were currently facilitated in the KORUS-AQ data set. In addition, air quality criteria species data from 264 nation-wide ground monitoring sites with 5 minute temporal resolution during the whole campaign period were supplemented to cover mostly in densely populated urban areas, but sparsely in rural areas. The specific objectives of these ground sites were to provide highly comprehensive data set to coordinate the close collaborations among other research platforms including airborne measurements, remote sensing, and model studies. The continuous measurements at ground sites were well compared with repetitive low-level aircraft observations of NASA's DC-8 over Olympic Park and Taewha Forest site. Similarly, many ground measurements enabled the validation of chemical transport models and the remote sensing observations from ground and NASA's King Air. The observed results from inter-comparison studies in many reactive gases and aerosol compositions between different measurement methods and platforms will be presented. Compiling data sets from ground sites, source-wise analysis for ozone and aerosol, their in-situ formations, and transport characteristics by local/regional circulation will be discussed, too.

  20. A Remote Sensing-Based Tool for Assessing Rainfall-Driven Hazards

    Science.gov (United States)

    Wright, Daniel B.; Mantilla, Ricardo; Peters-Lidard, Christa D.

    2018-01-01

    RainyDay is a Python-based platform that couples rainfall remote sensing data with Stochastic Storm Transposition (SST) for modeling rainfall-driven hazards such as floods and landslides. SST effectively lengthens the extreme rainfall record through temporal resampling and spatial transposition of observed storms from the surrounding region to create many extreme rainfall scenarios. Intensity-Duration-Frequency (IDF) curves are often used for hazard modeling but require long records to describe the distribution of rainfall depth and duration and do not provide information regarding rainfall space-time structure, limiting their usefulness to small scales. In contrast, RainyDay can be used for many hazard applications with 1-2 decades of data, and output rainfall scenarios incorporate detailed space-time structure from remote sensing. Thanks to global satellite coverage, RainyDay can be used in inaccessible areas and developing countries lacking ground measurements, though results are impacted by remote sensing errors. RainyDay can be useful for hazard modeling under nonstationary conditions. PMID:29657544

  1. A component-based system for agricultural drought monitoring by remote sensing.

    Science.gov (United States)

    Dong, Heng; Li, Jun; Yuan, Yanbin; You, Lin; Chen, Chao

    2017-01-01

    In recent decades, various kinds of remote sensing-based drought indexes have been proposed and widely used in the field of drought monitoring. However, the drought-related software and platform development lag behind the theoretical research. The current drought monitoring systems focus mainly on information management and publishing, and cannot implement professional drought monitoring or parameter inversion modelling, especially the models based on multi-dimensional feature space. In view of the above problems, this paper aims at fixing this gap with a component-based system named RSDMS to facilitate the application of drought monitoring by remote sensing. The system is designed and developed based on Component Object Model (COM) to ensure the flexibility and extendibility of modules. RSDMS realizes general image-related functions such as data management, image display, spatial reference management, image processing and analysis, and further provides drought monitoring and evaluation functions based on internal and external models. Finally, China's Ningxia region is selected as the study area to validate the performance of RSDMS. The experimental results show that RSDMS provide an efficient and scalable support to agricultural drought monitoring.

  2. Ground-based hyperspectral imaging and terrestrial laser scanning for fracture characterization in the Mississippian Boone Formation

    Science.gov (United States)

    Sun, Lei; Khan, Shuhab D.; Sarmiento, Sergio; Lakshmikantha, M. R.; Zhou, Huawei

    2017-12-01

    Petroleum geoscientists have been using cores and well logs to study source rocks and reservoirs, however, the inherent discontinuous nature of these data cannot account for horizontal heterogeneities. Modern exploitation requires better understanding of important source rocks and reservoirs at outcrop scale. Remote sensing of outcrops is becoming a first order tool for reservoir analog studies including horizontal heterogeneities. This work used ground-based hyperspectral imaging, terrestrial laser scanning (TLS), and high-resolution photography to study a roadcut of the Boone Formation at Bella Vista, northwest Arkansas, and developed an outcrop model for reservoir analog analyses. The petroliferous Boone Formation consists of fossiliferous limestones interbedded with chert of early Mississippian age. We used remote sensing techniques to identify rock types and to collect 3D geometrical data. Mixture tuned matched filtering classification of hyperspectral data show that the outcrop is mostly limestones with interbedded chert nodules. 1315 fractures were classified according to their strata-bounding relationships, among these, larger fractures are dominantly striking in ENE - WSW directions. Fracture extraction data show that chert holds more fractures than limestones, and both vertical and horizontal heterogeneities exist in chert nodule distribution. Utilizing ground-based remote sensing, we have assembled a virtual outcrop model to extract mineral composition as well as fracture data from the model. We inferred anisotropy in vertical fracture permeability based on the dominancy of fracture orientations, the preferential distribution of fractures and distribution of chert nodules. These data are beneficial in reservoir analogs to study rock mechanics and fluid flow, and to improve well performances.

  3. Magnetic Field Sensing Based on Bi-Tapered Optical Fibers Using Spectral Phase Analysis.

    Science.gov (United States)

    Herrera-Piad, Luis A; Haus, Joseph W; Jauregui-Vazquez, Daniel; Sierra-Hernandez, Juan M; Estudillo-Ayala, Julian M; Lopez-Dieguez, Yanelis; Rojas-Laguna, Roberto

    2017-10-20

    A compact, magnetic field sensor system based on a short, bi-tapered optical fiber (BTOF) span lying on a magnetic tape was designed, fabricated, and characterized. We monitored the transmission spectrum from a broadband light source, which displayed a strong interference signal. After data collection, we applied a phase analysis of the interference optical spectrum. We here report the results on two fabricated, BTOFs with different interference spectrum characteristics; we analyzed the signal based on the interference between a high-order modal component and the core fiber mode. The sensor exhibited a linear response for magnetic field increments, and we achieved a phase sensitivity of around 0.28 rad/mT. The sensing setup presented remote sensing operation and low-cost transducer magnetic material.

  4. Magnetic Field Sensing Based on Bi-Tapered Optical Fibers Using Spectral Phase Analysis

    Directory of Open Access Journals (Sweden)

    Luis A. Herrera-Piad

    2017-10-01

    Full Text Available A compact, magnetic field sensor system based on a short, bi-tapered optical fiber (BTOF span lying on a magnetic tape was designed, fabricated, and characterized. We monitored the transmission spectrum from a broadband light source, which displayed a strong interference signal. After data collection, we applied a phase analysis of the interference optical spectrum. We here report the results on two fabricated, BTOFs with different interference spectrum characteristics; we analyzed the signal based on the interference between a high-order modal component and the core fiber mode. The sensor exhibited a linear response for magnetic field increments, and we achieved a phase sensitivity of around 0.28 rad/mT. The sensing setup presented remote sensing operation and low-cost transducer magnetic material.

  5. Enhancing our Understanding of Snowfall Modes with Ground-Based Observations

    Science.gov (United States)

    Pettersen, C.; Kulie, M.; Petersen, W. A.; Bliven, L. F.; Wood, N.

    2016-12-01

    Snowfall can be broadly categorized into deep and shallow events based on the vertical distribution of the precipitating ice. Remotely sensed data refine these precipitation categories and aid in discerning the underlying macro- and microphysical mechanisms. The unique patterns in the remotely sensed instruments observations can potentially connect distinct modes of snowfall to specific processes. Though satellites can observe and recognize these patterns in snowfall, these measurements are limited - particularly in cases of shallow and light precipitation, as the snow may be too close to the surface or below the detection limits of the instrumentation. By enhancing satellite measurements with ground-based instrumentation, whether with limited-term field campaigns or long-term strategic sites, we can further our understanding and assumptions about different snowfall modes and how they are measured from spaceborne instruments. Presented are three years of data from a ground-based instrument suite consisting of a MicroRain Radar (MRR; optimized for snow events) and a Precipitation Imaging Package (PIP). These instruments are located at the Marquette, Michigan National Weather Service Weather Forecast Office to: a) use coincident meteorological measurements and observations to enhance our understanding of the thermodynamic drivers and b) showcase these instruments in an operational setting to enhance forecasts of shallow snow events. Three winters of MRR and PIP measurements are partitioned, based on meteorological surface observations, into two-dimensional histograms of reflectivity and particle size distribution data. These statistics improve our interpretation of deep versus shallow precipitation. Additionally, these statistical techniques are applied to similar datasets from Global Precipitation Measurement field campaigns for further insight into cloud and precipitation macro- and microphysical processes.

  6. Acute carbon dioxide avoidance in Caenorhabditis elegans.

    Science.gov (United States)

    Hallem, Elissa A; Sternberg, Paul W

    2008-06-10

    Carbon dioxide is produced as a by-product of cellular respiration by all aerobic organisms and thus serves for many animals as an important indicator of food, mates, and predators. However, whether free-living terrestrial nematodes such as Caenorhabditis elegans respond to CO2 was unclear. We have demonstrated that adult C. elegans display an acute avoidance response upon exposure to CO2 that is characterized by the cessation of forward movement and the rapid initiation of backward movement. This response is mediated by a cGMP signaling pathway that includes the cGMP-gated heteromeric channel TAX-2/TAX-4. CO2 avoidance is modulated by multiple signaling molecules, including the neuropeptide Y receptor NPR-1 and the calcineurin subunits TAX-6 and CNB-1. Nutritional status also modulates CO2 responsiveness via the insulin and TGFbeta signaling pathways. CO2 response is mediated by a neural circuit that includes the BAG neurons, a pair of sensory neurons of previously unknown function. TAX-2/TAX-4 function in the BAG neurons to mediate acute CO2 avoidance. Our results demonstrate that C. elegans senses and responds to CO2 using multiple signaling pathways and a neural network that includes the BAG neurons and that this response is modulated by the physiological state of the worm.

  7. Energy, mass, model-based displays, and memory recall

    International Nuclear Information System (INIS)

    Beltracchi, L.

    1989-01-01

    The operation of a pressurized water reactor in the context of the conservation laws for energy and mass is discussed. These conservation laws are the basis of the Rankine heat engine cycle. Computer graphic implementation of the heat engine cycle, in terms of temperature-entropy coordinates for water, serves as a model-based display of the plant process. A human user of this display, trained in first principles of the process, may exercise a monitoring strategy based on the conservation laws

  8. Analysis of Compression Algorithm in Ground Collision Avoidance Systems (Auto-GCAS)

    Science.gov (United States)

    Schmalz, Tyler; Ryan, Jack

    2011-01-01

    Automatic Ground Collision Avoidance Systems (Auto-GCAS) utilizes Digital Terrain Elevation Data (DTED) stored onboard a plane to determine potential recovery maneuvers. Because of the current limitations of computer hardware on military airplanes such as the F-22 and F-35, the DTED must be compressed through a lossy technique called binary-tree tip-tilt. The purpose of this study is to determine the accuracy of the compressed data with respect to the original DTED. This study is mainly interested in the magnitude of the error between the two as well as the overall distribution of the errors throughout the DTED. By understanding how the errors of the compression technique are affected by various factors (topography, density of sampling points, sub-sampling techniques, etc.), modifications can be made to the compression technique resulting in better accuracy. This, in turn, would minimize unnecessary activation of A-GCAS during flight as well as maximizing its contribution to fighter safety.

  9. a Universal De-Noising Algorithm for Ground-Based LIDAR Signal

    Science.gov (United States)

    Ma, Xin; Xiang, Chengzhi; Gong, Wei

    2016-06-01

    Ground-based lidar, working as an effective remote sensing tool, plays an irreplaceable role in the study of atmosphere, since it has the ability to provide the atmospheric vertical profile. However, the appearance of noise in a lidar signal is unavoidable, which leads to difficulties and complexities when searching for more information. Every de-noising method has its own characteristic but with a certain limitation, since the lidar signal will vary with the atmosphere changes. In this paper, a universal de-noising algorithm is proposed to enhance the SNR of a ground-based lidar signal, which is based on signal segmentation and reconstruction. The signal segmentation serving as the keystone of the algorithm, segments the lidar signal into three different parts, which are processed by different de-noising method according to their own characteristics. The signal reconstruction is a relatively simple procedure that is to splice the signal sections end to end. Finally, a series of simulation signal tests and real dual field-of-view lidar signal shows the feasibility of the universal de-noising algorithm.

  10. UAS-Borne Photogrammetry for Surface Topographic Characterization: A Ground-Truth Baseline for Future Change Detection and Refinement of Scaled Remotely-Sensed Datasets

    Science.gov (United States)

    Coppersmith, R.; Schultz-Fellenz, E. S.; Sussman, A. J.; Vigil, S.; Dzur, R.; Norskog, K.; Kelley, R.; Miller, L.

    2015-12-01

    While long-term objectives of monitoring and verification regimes include remote characterization and discrimination of surficial geologic and topographic features at sites of interest, ground truth data is required to advance development of remote sensing techniques. Increasingly, it is desirable for these ground-based or ground-proximal characterization methodologies to be as nimble, efficient, non-invasive, and non-destructive as their higher-altitude airborne counterparts while ideally providing superior resolution. For this study, the area of interest is an alluvial site at the Nevada National Security Site intended for use in the Source Physics Experiment's (Snelson et al., 2013) second phase. Ground-truth surface topographic characterization was performed using a DJI Inspire 1 unmanned aerial system (UAS), at very low altitude (clouds. Within the area of interest, careful installation of surveyed ground control fiducial markers supplied necessary targets for field collection, and information for model georectification. The resulting model includes a Digital Elevation Model derived from 2D imagery. It is anticipated that this flexible and versatile characterization process will provide point cloud data resolution equivalent to a purely ground-based LiDAR scanning deployment (e.g., 1-2cm horizontal and vertical resolution; e.g., Sussman et al., 2012; Schultz-Fellenz et al., 2013). In addition to drastically increasing time efficiency in the field, the UAS method also allows for more complete coverage of the study area when compared to ground-based LiDAR. Comparison and integration of these data with conventionally-acquired airborne LiDAR data from a higher-altitude (~ 450m) platform will aid significantly in the refinement of technologies and detection capabilities of remote optical systems to identify and detect surface geologic and topographic signatures of interest. This work includes a preliminary comparison of surface signatures detected from varying

  11. A display to support knowledge based behavior

    International Nuclear Information System (INIS)

    Lindsay, R.W.

    1990-01-01

    A computerized display has been created for the Experimental Breeder Reactor II (EBR-II) that incorporates information from plant sensors in a thermodynamic model display. The display is designed to provide an operator with an overall view of the plant process as a heat engine. The thermodynamics of the plant are depicted through the use of ionic figures, animated by plant signals, that are related to the major plant components and systems such as the reactor, intermediate heat exchanger, secondary system, evaporators, superheaters, steam system, steam drum, and turbine-generator. This display supports knowledge based reasoning for the operator as well as providing the traditional rule and skill based behavior, and includes side benefits such a inherent signal validation

  12. A comparision between satellite based and drone based remote sensing technology to achieve sustainable development: a review

    Directory of Open Access Journals (Sweden)

    Babankumar Bansod

    2017-12-01

    Full Text Available Precision agriculture is a way to manage the crop yield resources like water, fertilizers, soil, seeds in order to increase production, quality, gain and reduce squander products so that the existing system become eco-friendly. The main target of precision agriculture is to match resources and execution according to the crop and climate to ameliorate the effects of Praxis. Global Positioning System, Geographic Information System, Remote sensing technologies and various sensors are used in Precision farming for identifying the variability in field and using different methods to deal with them. Satellite based remote sensing is used to study the variability in crop and ground but suffer from various disadvantageous such as prohibited use, high price, less revisiting them, poor resolution due to great height, Unmanned Aerial Vehicle (UAV is other alternative option for application in precision farming. UAV overcomes the drawback of the ground based system, i.e. inaccessibility to muddy and very dense regions. Hovering at a peak of 500 meter - 1000 meter is good enough to offer various advantageous in image acquisition such as high spatial and temporal resolution, full flexibility, low cost. Recent studies of application of UAV in precision farming indicate advanced designing of UAV, enhancement in georeferencing and the mosaicking of image, analysis and extraction of information required for supplying a true end product to farmers. This paper also discusses the various platforms of UAV used in farming applications, its technical constraints, seclusion rites, reliability and safety.

  13. Sensor-based whole-arm obstacle avoidance for unstructured environments

    International Nuclear Information System (INIS)

    Wintenberg, AL.; Butler, P.L.; Babcock, S.M.; Ericson, M.N.; Britton, C.L. Jr.; Hamel, W.R.

    1992-01-01

    Whole-arm obstacle avoidance is needed for a variety of robotic applications in the Environmental Restoration and Waste Management (ER ampersand WM) Program. Typical industrial applications of robotics involve well-defined work spaces, allowing a predetermined knowledge of collision-free paths for manipulator motion. In the unstructured or poorly defined hazardous environments of the ER ampersand WM program, the potential for significant problems resulting from collisions between manipulators and the environment in which they are utilized is great. A sensing system under development, which will provide protection against such collisions, is described in this paper

  14. A change detection method for remote sensing image based on LBP and SURF feature

    Science.gov (United States)

    Hu, Lei; Yang, Hao; Li, Jin; Zhang, Yun

    2018-04-01

    Finding the change in multi-temporal remote sensing image is important in many the image application. Because of the infection of climate and illumination, the texture of the ground object is more stable relative to the gray in high-resolution remote sensing image. And the texture features of Local Binary Patterns (LBP) and Speeded Up Robust Features (SURF) are outstanding in extracting speed and illumination invariance. A method of change detection for matched remote sensing image pair is present, which compares the similarity by LBP and SURF to detect the change and unchanged of the block after blocking the image. And region growing is adopted to process the block edge zone. The experiment results show that the method can endure some illumination change and slight texture change of the ground object.

  15. Principle and Control Design of Active Ground-Fault Arc Suppression Device for Full Compensation of Ground Current

    DEFF Research Database (Denmark)

    Wang, Wen; Zeng, Xiangjun; Yan, Lingjie

    2017-01-01

    current into the neutral without any large-capacity reactors, and thus avoids the aforementioned overvoltage. It compensates all the active, reactive and harmonic components of the ground current to reliably extinguish the ground-fault arcs. A dual-loop voltage control method is proposed to realize arc...... suppression without capacitive current detection. Its time-based feature also brings the benefit of fast response on ground-fault arc suppression. The principle of full current compensation is analyzed, together with the controller design method of the proposed device. Experiment on a prototype was carried...

  16. Joint synthetic aperture radar plus ground moving target indicator from single-channel radar using compressive sensing

    Science.gov (United States)

    Thompson, Douglas; Hallquist, Aaron; Anderson, Hyrum

    2017-10-17

    The various embodiments presented herein relate to utilizing an operational single-channel radar to collect and process synthetic aperture radar (SAR) and ground moving target indicator (GMTI) imagery from a same set of radar returns. In an embodiment, data is collected by randomly staggering a slow-time pulse repetition interval (PRI) over a SAR aperture such that a number of transmitted pulses in the SAR aperture is preserved with respect to standard SAR, but many of the pulses are spaced very closely enabling movers (e.g., targets) to be resolved, wherein a relative velocity of the movers places them outside of the SAR ground patch. The various embodiments of image reconstruction can be based on compressed sensing inversion from undersampled data, which can be solved efficiently using such techniques as Bregman iteration. The various embodiments enable high-quality SAR reconstruction, and high-quality GMTI reconstruction from the same set of radar returns.

  17. High-Resolution Remote Sensing Image Building Extraction Based on Markov Model

    Science.gov (United States)

    Zhao, W.; Yan, L.; Chang, Y.; Gong, L.

    2018-04-01

    With the increase of resolution, remote sensing images have the characteristics of increased information load, increased noise, more complex feature geometry and texture information, which makes the extraction of building information more difficult. To solve this problem, this paper designs a high resolution remote sensing image building extraction method based on Markov model. This method introduces Contourlet domain map clustering and Markov model, captures and enhances the contour and texture information of high-resolution remote sensing image features in multiple directions, and further designs the spectral feature index that can characterize "pseudo-buildings" in the building area. Through the multi-scale segmentation and extraction of image features, the fine extraction from the building area to the building is realized. Experiments show that this method can restrain the noise of high-resolution remote sensing images, reduce the interference of non-target ground texture information, and remove the shadow, vegetation and other pseudo-building information, compared with the traditional pixel-level image information extraction, better performance in building extraction precision, accuracy and completeness.

  18. The Role of Model Fidelity in Model Predictive Control Based Hazard Avoidance in Unmanned Ground Vehicles Using Lidar Sensors

    Science.gov (United States)

    2013-03-08

    34 VPH : A New Laser Radar Based Obstacle Avoidance Method for Intelligent Mobile Robots", Proceedings of World Congress on Intelligent Control and...Automation, Hangzhou, China, 5, pp. 4681- 4685. [9] Gong, J., Duan, Y., Man, Y., and Xiong, G., 2007, " VPH +: An Enhanced Vector Polar Histogram Method

  19. A display to support knowledge based behavior

    International Nuclear Information System (INIS)

    Lindsay, R.W.

    1990-01-01

    This paper reports on a computerized display that has been created for the Experimental Breeder Reactor II that incorporates information from plant sensors in a thermodynamic model display. The display is designed to provide an operator with an overall view of the plant process as a heat engine. The thermodynamics of the plant are depicted through the use of iconic figures, animated by plant signals, that are related to the major plant components and systems such as the reactor, intermediate heat exchanger, secondary system, evaporators, superheaters, steam system, steam drum, and turbine-generator. This display supports knowledge based reasoning for the operator as well as providing data for the traditional rule and skill based behavior, and includes side benefits such as inherent signal validation

  20. Digital methods and remote sensing in archaeology archaeology in the age of sensing

    CERN Document Server

    Campana, Stefano

    2016-01-01

    This volume debuts the new scope of Remote Sensing, which was first defined as the analysis of data collected by sensors that were not in physical contact with the objects under investigation (using cameras, scanners, and radar systems operating from spaceborne or airborne platforms). A wider characterization is now possible: Remote Sensing can be any non-destructive approach to viewing the buried and nominally invisible evidence of past activity. Spaceborne and airborne sensors, now supplemented by laser scanning, are united using ground-based geophysical instruments and undersea remote sensing, as well as other non-invasive techniques such as surface collection or field-walking survey. Now, any method that enables observation of evidence on or beneath the surface of the earth, without impact on the surviving stratigraphy, is legitimately within the realm of Remote Sensing. The new interfaces and senses engaged in Remote Sensing appear throughout the book. On a philosophical level, this is about the landscap...

  1. Studies and Application of Remote Sensing Retrieval Method of Soil Moisture Content in Land Parcel Units in Irrigation Area

    Science.gov (United States)

    Zhu, H.; Zhao, H. L.; Jiang, Y. Z.; Zang, W. B.

    2018-05-01

    Soil moisture is one of the important hydrological elements. Obtaining soil moisture accurately and effectively is of great significance for water resource management in irrigation area. During the process of soil moisture content retrieval with multiremote sensing data, multi- remote sensing data always brings multi-spatial scale problems which results in inconformity of soil moisture content retrieved by remote sensing in different spatial scale. In addition, agricultural water use management has suitable spatial scale of soil moisture information so as to satisfy the demands of dynamic management of water use and water demand in certain unit. We have proposed to use land parcel unit as the minimum unit to do soil moisture content research in agricultural water using area, according to soil characteristics, vegetation coverage characteristics in underlying layer, and hydrological characteristic into the basis of study unit division. We have proposed division method of land parcel units. Based on multi thermal infrared and near infrared remote sensing data, we calculate the ndvi and tvdi index and make a statistical model between the tvdi index and soil moisture of ground monitoring station. Then we move forward to study soil moisture remote sensing retrieval method on land parcel unit scale. And the method has been applied in Hetao irrigation area. Results show that compared with pixel scale the soil moisture content in land parcel unit scale has displayed stronger correlation with true value. Hence, remote sensing retrieval method of soil moisture content in land parcel unit scale has shown good applicability in Hetao irrigation area. We converted the research unit into the scale of land parcel unit. Using the land parcel units with unified crops and soil attributes as the research units more complies with the characteristics of agricultural water areas, avoids the problems such as decomposition of mixed pixels and excessive dependence on high-resolution data

  2. Integrated Monitoring and Modeling of Carbon Dioxide Leakage Risk Using Remote Sensing, Ground-Based Monitoring, Atmospheric Models and Risk-Indexing Tools

    Science.gov (United States)

    Burton, E. A.; Pickles, W. L.; Gouveia, F. J.; Bogen, K. T.; Rau, G. H.; Friedmann, J.

    2006-12-01

    Correct assessment of the potential for CO2 leakage to the atmosphere or near surface is key to managing the risk associated with CO2 storage. Catastrophic, point-source leaks, diffuse seepage, and low leakage rates all merit assessment. Smaller leaks may be early warnings of catastrophic failures, and may be sufficient to damage natural vegetation or crops. Small leaks also may lead to cumulative build-up of lethal levels of CO2 in enclosed spaces, such as basements, groundwater-well head spaces, and caverns. Working with our ZERT partners, we are integrating a variety of monitoring and modeling approaches to understand how to assess potential health, property and environmental risks across this spectrum of leakage types. Remote sensing offers a rapid technique to monitor large areas for adverse environmental effects. If it can be deployed prior to the onset of storage operations, remote sensing also can document baseline conditions against which future claims of environmental damage can be compared. LLNL has been using hyperspectral imaging to detect plant stress associated with CO2 gas leakage, and has begun investigating use of NASA's new satellite or airborne instrumentation that directly measures gas compositions in the atmosphere. While remote sensing techniques have been criticized as lacking the necessary resolution to address environmental problems, new instruments and data processing techniques are demonstrated to resolve environmental changes at the scale associated with gas-leakage scenarios. During the shallow low-flow- CO2 release field experiments planned by ZERT, for the first time, we will have the opportunity to ground- truth hyperspectral data by simultaneous measurement of changes in hyperspectral readings, soil and root zone microbiology, ambient air, soil and aquifer CO2 concentrations. When monitoring data appear to indicate a CO2 leakage event, risk assessment and mitigation of that event requires a robust and nearly real-time method for

  3. CLINICAL SURFACES -- Activity-Based Computing for Distributed Multi-Display Environments in Hospitals

    DEFF Research Database (Denmark)

    Bardram, Jakob Eyvind; Bunde-Pedersen, Jonathan; Doryab, Afsaneh

    2009-01-01

    A multi-display environment (MDE) is made up of co-located and networked personal and public devices that form an integrated workspace enabling co-located group work. Traditionally, MDEs have, however, mainly been designed to support a single “smart room”, and have had little sense of the tasks...

  4. Csf Based Non-Ground Points Extraction from LIDAR Data

    Science.gov (United States)

    Shen, A.; Zhang, W.; Shi, H.

    2017-09-01

    Region growing is a classical method of point cloud segmentation. Based on the idea of collecting the pixels with similar properties to form regions, region growing is widely used in many fields such as medicine, forestry and remote sensing. In this algorithm, there are two core problems. One is the selection of seed points, the other is the setting of the growth constraints, in which the selection of the seed points is the foundation. In this paper, we propose a CSF (Cloth Simulation Filtering) based method to extract the non-ground seed points effectively. The experiments have shown that this method can obtain a group of seed spots compared with the traditional methods. It is a new attempt to extract seed points

  5. A component-based system for agricultural drought monitoring by remote sensing.

    Directory of Open Access Journals (Sweden)

    Heng Dong

    Full Text Available In recent decades, various kinds of remote sensing-based drought indexes have been proposed and widely used in the field of drought monitoring. However, the drought-related software and platform development lag behind the theoretical research. The current drought monitoring systems focus mainly on information management and publishing, and cannot implement professional drought monitoring or parameter inversion modelling, especially the models based on multi-dimensional feature space. In view of the above problems, this paper aims at fixing this gap with a component-based system named RSDMS to facilitate the application of drought monitoring by remote sensing. The system is designed and developed based on Component Object Model (COM to ensure the flexibility and extendibility of modules. RSDMS realizes general image-related functions such as data management, image display, spatial reference management, image processing and analysis, and further provides drought monitoring and evaluation functions based on internal and external models. Finally, China's Ningxia region is selected as the study area to validate the performance of RSDMS. The experimental results show that RSDMS provide an efficient and scalable support to agricultural drought monitoring.

  6. The case for transparent depth display

    NARCIS (Netherlands)

    Kooi, F.L.

    2003-01-01

    Purpose: The continuing developments in display technology have resulted in the ability to present increasing amounts of data on computer displays. One of the coming break-throughs is generally believed to be the introduction of '3-D displays': displays with a true sense of depth. Though these types

  7. Grounding Lines Detecting Using LANDSAT8 Oli and CRYOSAT-2 Data Fusion

    Science.gov (United States)

    Li, F.; Guo, Y.; Zhang, Y.; Zhang, S.

    2018-04-01

    The grounding zone is the region where ice transitions from grounded ice sheet to freely floating ice shelf, grounding lines are actually more of a zone, typically over several kilometers. The mass loss from Antarctica is strongly linked to changes in the ice shelves and their grounding lines, since the variation in the grounding line can result in very rapid changes in glacier and ice-shelf behavior. Based on remote sensing observations, five global Antarctic grounding line products have been released internationally, including MOA, ASAID, ICESat, MEaSUREs, and Synthesized grounding lines. However, the five products could not provide the annual grounding line products of the whole Antarctic, even some products have stopped updating, which limits the time series analysis of Antarctic material balance to a certain extent. Besides, the accurate of single remote-sensing data based grounding line products is far from satisficed. Therefore, we use algorithms to extract grounding lines with SAR and Cryosat-2 data respectively, and combine the results of two kinds of grounding lines to obtain new products, we obtain a mature grounding line extraction algorithm process, so that we can realize the extraction of grounding line of the Antarctic each year in the future. The comparison between fusion results and the MOA product results indicate that there is a maximum deviation of 188.67 meters between the MOA product and the fusion result.

  8. Sensor-based whole-arm obstacle avoidance for unstructured environments

    International Nuclear Information System (INIS)

    Wintenberg, A.L.; Butler, P.L.; Babcock, S.M.; Ericson, M.N.; Armstrong, G.A.; Britton, C.L. Jr.; Hamel, W.R.

    1992-01-01

    Whole-arm obstacle avoidance is needed for a variety of robotic applications in the Environmental Restoration and Waste Management (ER ampersand WM) Program. Typical industrial applications of robotics involve well-defined workspaces, allowing a predetermined knowledge of collision-free paths for manipulator motion. However, many hazardous environments are unstructured or poorly defined, providing a significant potential for collisions between manipulators and the environment. In order to allow applications of robotics in such situations, a sensing system is under development which will provide protection against collisions. Specifics of this system including system architecture and projected implementation are described

  9. SERS-Fluorescence Dual-Mode pH-Sensing Method Based on Janus Microparticles.

    Science.gov (United States)

    Yue, Shuai; Sun, Xiaoting; Wang, Ning; Wang, Yaning; Wang, Yue; Xu, Zhangrun; Chen, Mingli; Wang, Jianhua

    2017-11-15

    A surface-enhanced Raman scattering (SERS)-fluorescence dual-mode pH-sensing method based on Janus microgels was developed, which combined the advantages of high specificity offered by SERS and fast imaging afforded by fluorescence. Dual-mode probes, pH-dependent 4-mercaptobenzoic acid, and carbon dots were individually encapsulated in the independent hemispheres of Janus microparticles fabricated via a centrifugal microfluidic chip. On the basis of the obvious volumetric change of hydrogels in different pHs, the Janus microparticles were successfully applied for sensitive and reliable pH measurement from 1.0 to 8.0, and the two hemispheres showed no obvious interference. The proposed method addressed the limitation that sole use of the SERS-based pH sensing usually failed in strong acidic media. The gastric juice pH and extracellular pH change were measured separately in vitro using the Janus microparticles, which confirmed the validity of microgels for pH sensing. The microparticles exhibited good stability, reversibility, biocompatibility, and ideal semipermeability for avoiding protein contamination, and they have the potential to be implantable sensors to continuously monitor pH in vivo.

  10. Design, Implementation and Characterization of a Quantum-Dot-Based Volumetric Display

    Science.gov (United States)

    Hirayama, Ryuji; Naruse, Makoto; Nakayama, Hirotaka; Tate, Naoya; Shiraki, Atsushi; Kakue, Takashi; Shimobaba, Tomoyoshi; Ohtsu, Motoichi; Ito, Tomoyoshi

    2015-02-01

    In this study, we propose and experimentally demonstrate a volumetric display system based on quantum dots (QDs) embedded in a polymer substrate. Unlike conventional volumetric displays, our system does not require electrical wiring; thus, the heretofore unavoidable issue of occlusion is resolved because irradiation by external light supplies the energy to the light-emitting voxels formed by the QDs. By exploiting the intrinsic attributes of the QDs, the system offers ultrahigh definition and a wide range of colours for volumetric displays. In this paper, we discuss the design, implementation and characterization of the proposed volumetric display's first prototype. We developed an 8 × 8 × 8 display comprising two types of QDs. This display provides multicolour three-type two-dimensional patterns when viewed from different angles. The QD-based volumetric display provides a new way to represent images and could be applied in leisure and advertising industries, among others.

  11. Neural Correlates of Auditory Figure-Ground Segregation Based on Temporal Coherence.

    Science.gov (United States)

    Teki, Sundeep; Barascud, Nicolas; Picard, Samuel; Payne, Christopher; Griffiths, Timothy D; Chait, Maria

    2016-09-01

    To make sense of natural acoustic environments, listeners must parse complex mixtures of sounds that vary in frequency, space, and time. Emerging work suggests that, in addition to the well-studied spectral cues for segregation, sensitivity to temporal coherence-the coincidence of sound elements in and across time-is also critical for the perceptual organization of acoustic scenes. Here, we examine pre-attentive, stimulus-driven neural processes underlying auditory figure-ground segregation using stimuli that capture the challenges of listening in complex scenes where segregation cannot be achieved based on spectral cues alone. Signals ("stochastic figure-ground": SFG) comprised a sequence of brief broadband chords containing random pure tone components that vary from 1 chord to another. Occasional tone repetitions across chords are perceived as "figures" popping out of a stochastic "ground." Magnetoencephalography (MEG) measurement in naïve, distracted, human subjects revealed robust evoked responses, commencing from about 150 ms after figure onset that reflect the emergence of the "figure" from the randomly varying "ground." Neural sources underlying this bottom-up driven figure-ground segregation were localized to planum temporale, and the intraparietal sulcus, demonstrating that this area, outside the "classic" auditory system, is also involved in the early stages of auditory scene analysis." © The Author 2016. Published by Oxford University Press.

  12. Supervised Gaussian mixture model based remote sensing image ...

    African Journals Online (AJOL)

    Using the supervised classification technique, both simulated and empirical satellite remote sensing data are used to train and test the Gaussian mixture model algorithm. For the purpose of validating the experiment, the resulting classified satellite image is compared with the ground truth data. For the simulated modelling, ...

  13. Preliminary Assessment of Detection Efficiency for the Geostationary Lightning Mapper Using Intercomparisons with Ground-Based Systems

    Science.gov (United States)

    Bateman, Monte; Mach, Douglas; Blakeslee, Richard J.; Koshak, William

    2018-01-01

    As part of the calibration/validation (cal/val) effort for the Geostationary Lightning Mapper (GLM) on GOES-16, we need to assess instrument performance (detection efficiency and accuracy). One major effort is to calculate the detection efficiency of GLM by comparing to multiple ground-based systems. These comparisons will be done pair-wise between GLM and each other source. A complication in this process is that the ground-based systems sense different properties of the lightning signal than does GLM (e.g., RF vs. optical). Also, each system has a different time and space resolution and accuracy. Preliminary results indicate that GLM is performing at or above its specification.

  14. Ground-based photo monitoring

    Science.gov (United States)

    Frederick C. Hall

    2000-01-01

    Ground-based photo monitoring is repeat photography using ground-based cameras to document change in vegetation or soil. Assume those installing the photo location will not be the ones re-photographing it. This requires a protocol that includes: (1) a map to locate the monitoring area, (2) another map diagramming the photographic layout, (3) type and make of film such...

  15. An In Depth Look at Lightning Trends in Hurricane Harvey using Satellite and Ground-Based Measurements

    Science.gov (United States)

    Ringhausen, J.

    2017-12-01

    This research combines satellite measurements of lightning in Hurricane Harvey with ground-based lightning measurements to get a better sense of the total lightning occurring in the hurricane, both intra-cloud (IC) and cloud-to-ground (CG), and how it relates to the intensification and weakening of the tropical system. Past studies have looked at lightning trends in hurricanes using the space based Lightning Imaging Sensor (LIS) or ground-based lightning detection networks. However, both of these methods have drawbacks. For instance, LIS was in low earth orbit, which limited lightning observations to 90 seconds for a particular point on the ground; hence, continuous lightning coverage of a hurricane was not possible. Ground-based networks can have a decreased detection efficiency, particularly for ICs, over oceans where hurricanes generally intensify. With the launch of the Geostationary Lightning Mapper (GLM) on the GOES-16 satellite, researchers can study total lightning continuously over the lifetime of a tropical cyclone. This study utilizes GLM to investigate total lightning activity in Hurricane Harvey temporally; this is augmented with spatial analysis relative to hurricane structure, similar to previous studies. Further, GLM and ground-based network data are combined using Bayesian techniques in a new manner to leverage the strengths of each detection method. This methodology 1) provides a more complete estimate of lightning activity and 2) enables the derivation of the IC:CG ratio (Z-ratio) throughout the time period of the study. In particular, details of the evolution of the Z-ratio in time and space are presented. In addition, lightning stroke spatiotemporal trends are compared to lightning flash trends. This research represents a new application of lightning data that can be used in future study of tropical cyclone intensification and weakening.

  16. Visual displays and Neuro-Linguistic Programming

    Energy Technology Data Exchange (ETDEWEB)

    Brown-VanHoozer, S.A. [Argonne National Lab., Idaho Falls, ID (United States); VanHoozer, W.R. [Tranceformations Unlimited, Rigby, ID (United States)

    1994-10-01

    Advancement of computer technology is forthcoming at such a rapid pace that the research concerning the interplay of humans and computer technology is lagging far behind. One area of particular concern is the design of visual displays that are pragmatic, ``user friendly,`` and ``user assisting.`` When engineers design visual displays, they generally do so methodically and logically, but only from within their own individual perspective or ``model of the world.`` They select the human aspects which make sense to them and not necessarily to non-engineers, operators, and others. The model design is what the engineer chooses to relate, based on his or her perspective of reality. These choices limit the model design thereby excluding the users` perspective. A set of techniques which can be used to assist the designers in expanding their choices and include the users` model is Neuro-Linguistic Programming (NLP).

  17. Radar-based collision avoidance for unmanned surface vehicles

    Science.gov (United States)

    Zhuang, Jia-yuan; Zhang, Lei; Zhao, Shi-qi; Cao, Jian; Wang, Bo; Sun, Han-bing

    2016-12-01

    Unmanned surface vehicles (USVs) have become a focus of research because of their extensive applications. To ensure safety and reliability and to perform complex tasks autonomously, USVs are required to possess accurate perception of the environment and effective collision avoidance capabilities. To achieve these, investigation into realtime marine radar target detection and autonomous collision avoidance technologies is required, aiming at solving the problems of noise jamming, uneven brightness, target loss, and blind areas in marine radar images. These technologies should also satisfy the requirements of real-time and reliability related to high navigation speeds of USVs. Therefore, this study developed an embedded collision avoidance system based on the marine radar, investigated a highly real-time target detection method which contains adaptive smoothing algorithm and robust segmentation algorithm, developed a stable and reliable dynamic local environment model to ensure the safety of USV navigation, and constructed a collision avoidance algorithm based on velocity obstacle (V-obstacle) which adjusts the USV's heading and speed in real-time. Sea trials results in multi-obstacle avoidance firstly demonstrate the effectiveness and efficiency of the proposed avoidance system, and then verify its great adaptability and relative stability when a USV sailing in a real and complex marine environment. The obtained results will improve the intelligent level of USV and guarantee the safety of USV independent sailing.

  18. Techniques for optimizing human-machine information transfer related to real-time interactive display systems

    Science.gov (United States)

    Granaas, Michael M.; Rhea, Donald C.

    1989-01-01

    In recent years the needs of ground-based researcher-analysts to access real-time engineering data in the form of processed information has expanded rapidly. Fortunately, the capacity to deliver that information has also expanded. The development of advanced display systems is essential to the success of a research test activity. Those developed at the National Aeronautics and Space Administration (NASA), Western Aeronautical Test Range (WATR), range from simple alphanumerics to interactive mapping and graphics. These unique display systems are designed not only to meet basic information display requirements of the user, but also to take advantage of techniques for optimizing information display. Future ground-based display systems will rely heavily not only on new technologies, but also on interaction with the human user and the associated productivity with that interaction. The psychological abilities and limitations of the user will become even more important in defining the difference between a usable and a useful display system. This paper reviews the requirements for development of real-time displays; the psychological aspects of design such as the layout, color selection, real-time response rate, and interactivity of displays; and an analysis of some existing WATR displays.

  19. PV Systems Reliability Final Technical Report: Ground Fault Detection

    Energy Technology Data Exchange (ETDEWEB)

    Lavrova, Olga [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Flicker, Jack David [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Johnson, Jay [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2016-01-01

    We have examined ground faults in PhotoVoltaic (PV) arrays and the efficacy of fuse, current detection (RCD), current sense monitoring/relays (CSM), isolation/insulation (Riso) monitoring, and Ground Fault Detection and Isolation (GFID) using simulations based on a Simulation Program with Integrated Circuit Emphasis SPICE ground fault circuit model, experimental ground faults installed on real arrays, and theoretical equations.

  20. Space situational awareness satellites and ground based radiation counting and imaging detector technology

    International Nuclear Information System (INIS)

    Jansen, Frank; Behrens, Joerg; Pospisil, Stanislav; Kudela, Karel

    2011-01-01

    We review the current status from the scientific and technological point of view of solar energetic particles, solar and galactic cosmic ray measurements as well as high energy UV-, X- and gamma-ray imaging of the Sun. These particles and electromagnetic data are an important tool for space situational awareness (SSA) aspects like space weather storm predictions to avoid failures in space, air and ground based technological systems. Real time data acquisition, position and energy sensitive imaging are demanded by the international space weather forecast services. We present how newly developed, highly miniaturized radiation detectors can find application in space in view of future SSA related satellites as a novel space application due to their counting and imaging capabilities.

  1. Space situational awareness satellites and ground based radiation counting and imaging detector technology

    Energy Technology Data Exchange (ETDEWEB)

    Jansen, Frank, E-mail: frank.jansen@dlr.de [DLR Institute of Space Systems, Robert-Hooke-Str. 7, 28359 Bremen (Germany); Behrens, Joerg [DLR Institute of Space Systems, Robert-Hooke-Str. 7, 28359 Bremen (Germany); Pospisil, Stanislav [Czech Technical University, IEAP, 12800 Prague 2, Horska 3a/22 (Czech Republic); Kudela, Karel [Slovak Academy of Sciences, IEP, 04001 Kosice, Watsonova 47 (Slovakia)

    2011-05-15

    We review the current status from the scientific and technological point of view of solar energetic particles, solar and galactic cosmic ray measurements as well as high energy UV-, X- and gamma-ray imaging of the Sun. These particles and electromagnetic data are an important tool for space situational awareness (SSA) aspects like space weather storm predictions to avoid failures in space, air and ground based technological systems. Real time data acquisition, position and energy sensitive imaging are demanded by the international space weather forecast services. We present how newly developed, highly miniaturized radiation detectors can find application in space in view of future SSA related satellites as a novel space application due to their counting and imaging capabilities.

  2. A Reconfigurable Readout Integrated Circuit for Heterogeneous Display-Based Multi-Sensor Systems

    Directory of Open Access Journals (Sweden)

    Kyeonghwan Park

    2017-04-01

    Full Text Available This paper presents a reconfigurable multi-sensor interface and its readout integrated circuit (ROIC for display-based multi-sensor systems, which builds up multi-sensor functions by utilizing touch screen panels. In addition to inherent touch detection, physiological and environmental sensor interfaces are incorporated. The reconfigurable feature is effectively implemented by proposing two basis readout topologies of amplifier-based and oscillator-based circuits. For noise-immune design against various noises from inherent human-touch operations, an alternate-sampling error-correction scheme is proposed and integrated inside the ROIC, achieving a 12-bit resolution of successive approximation register (SAR of analog-to-digital conversion without additional calibrations. A ROIC prototype that includes the whole proposed functions and data converters was fabricated in a 0.18 μm complementary metal oxide semiconductor (CMOS process, and its feasibility was experimentally verified to support multiple heterogeneous sensing functions of touch, electrocardiogram, body impedance, and environmental sensors.

  3. Spatio-temporal monitoring of cotton cultivation using ground-based and airborne multispectral sensors in GIS environment.

    Science.gov (United States)

    Papadopoulos, Antonis; Kalivas, Dionissios; Theocharopoulos, Sid

    2017-07-01

    Multispectral sensor capability of capturing reflectance data at several spectral channels, together with the inherent reflectance responses of various soils and especially plant surfaces, has gained major interest in crop production. In present study, two multispectral sensing systems, a ground-based and an aerial-based, were applied for the multispatial and temporal monitoring of two cotton fields in central Greece. The ground-based system was Crop Circle ACS-430, while the aerial consisted of a consumer-level quadcopter (Phantom 2) and a modified Hero3+ Black digital camera. The purpose of the research was to monitor crop growth with the two systems and investigate possible interrelations between the derived well-known normalized difference vegetation index (NDVI). Five data collection campaigns were conducted during the cultivation period and concerned scanning soil and plants with the ground-based sensor and taking aerial photographs of the fields with the unmanned aerial system. According to the results, both systems successfully monitored cotton growth stages in terms of space and time. The mean values of NDVI changes through time as retrieved by the ground-based system were satisfactorily modelled by a second-order polynomial equation (R 2 0.96 in Field 1 and 0.99 in Field 2). Further, they were highly correlated (r 0.90 in Field 1 and 0.74 in Field 2) with the according values calculated via the aerial-based system. The unmanned aerial system (UAS) can potentially substitute crop scouting as it concerns a time-effective, non-destructive and reliable way of soil and plant monitoring.

  4. Methane Emissions from Bangladesh: Bridging the Gap Between Ground-based and Space-borne Estimates

    Science.gov (United States)

    Peters, C.; Bennartz, R.; Hornberger, G. M.

    2015-12-01

    Gaining an understanding of methane (CH4) emission sources and atmospheric dispersion is an essential part of climate change research. Large-scale and global studies often rely on satellite observations of column CH4 mixing ratio whereas high-spatial resolution estimates rely on ground-based measurements. Extrapolation of ground-based measurements on, for example, rice paddies to broad region scales is highly uncertain because of spatio-temporal variability. We explore the use of ground-based river stage measurements and independent satellite observations of flooded area along with satellite measurements of CH4 mixing ratio to estimate the extent of methane emissions. Bangladesh, which comprises most of the Ganges Brahmaputra Meghna (GBM) delta, is a region of particular interest for studying spatio-temporal variation of methane emissions due to (1) broadscale rice cultivation and (2) seasonal flooding and atmospheric convection during the monsoon. Bangladesh and its deltaic landscape exhibit a broad range of environmental, economic, and social circumstances that are relevant to many nations in South and Southeast Asia. We explore the seasonal enhancement of CH4 in Bangladesh using passive remote sensing spectrometer CH4 products from the SCanning Imaging Absorption SpectroMeter for Atmospheric CHartographY (SCIAMACHY) and the Atmospheric Infrared Sounder (AIRS). The seasonal variation of CH4 is compared to independent estimates of seasonal flooding from water gauge stations and space-based passive microwave water-to-land fractions from the Tropical Rainfall Measuring Mission Microwave Imager (TRMM-TMI). Annual cycles in inundation (natural and anthropogenic) and atmospheric CH4 concentrations show highly correlated seasonal signals. NOAA's HYSPLIT model is used to determine atmospheric residence time of ground CH4 fluxes. Using the satellite observations, we can narrow the large uncertainty in extrapolation of ground-based CH4 emission estimates from rice paddies

  5. Generalized eigenvalue based spectrum sensing

    KAUST Repository

    Shakir, Muhammad

    2012-01-01

    Spectrum sensing is one of the fundamental components in cognitive radio networks. In this chapter, a generalized spectrum sensing framework which is referred to as Generalized Mean Detector (GMD) has been introduced. In this context, we generalize the detectors based on the eigenvalues of the received signal covariance matrix and transform the eigenvalue based spectrum sensing detectors namely: (i) the Eigenvalue Ratio Detector (ERD) and two newly proposed detectors which are referred to as (ii) the GEometric Mean Detector (GEMD) and (iii) the ARithmetic Mean Detector (ARMD) into an unified framework of generalize spectrum sensing. The foundation of the proposed framework is based on the calculation of exact analytical moments of the random variables of the decision threshold of the respective detectors. The decision threshold has been calculated in a closed form which is based on the approximation of Cumulative Distribution Functions (CDFs) of the respective test statistics. In this context, we exchange the analytical moments of the two random variables of the respective test statistics with the moments of the Gaussian (or Gamma) distribution function. The performance of the eigenvalue based detectors is compared with the several traditional detectors including the energy detector (ED) to validate the importance of the eigenvalue based detectors and the performance of the GEMD and the ARMD particularly in realistic wireless cognitive radio network. Analytical and simulation results show that the newly proposed detectors yields considerable performance advantage in realistic spectrum sensing scenarios. Moreover, the presented results based on proposed approximation approaches are in perfect agreement with the empirical results. © 2012 Springer Science+Business Media Dordrecht.

  6. Evidence for an expectancy-based theory of avoidance behaviour.

    Science.gov (United States)

    Declercq, Mieke; De Houwer, Jan; Baeyens, Frank

    2008-01-01

    In most studies on avoidance learning, participants receive an aversive unconditioned stimulus after a warning signal is presented, unless the participant performs a particular response. Lovibond (2006) recently proposed a cognitive theory of avoidance learning, according to which avoidance behaviour is a function of both Pavlovian and instrumental conditioning. In line with this theory, we found that avoidance behaviour was based on an integration of acquired knowledge about, on the one hand, the relation between stimuli and, on the other hand, the relation between behaviour and stimuli.

  7. REMOTE-SENSING-BASED BIOPHYSICAL MODELS FOR ESTIMATING LAI OF IRRIGATED CROPS IN MURRY DARLING BASIN

    Directory of Open Access Journals (Sweden)

    I. Wittamperuma

    2012-07-01

    Full Text Available Remote sensing is a rapid and reliable method for estimating crop growth data from individual plant to crops in irrigated agriculture ecosystem. The LAI is one of the important biophysical parameter for determining vegetation health, biomass, photosynthesis and evapotranspiration (ET for the modelling of crop yield and water productivity. Ground measurement of this parameter is tedious and time-consuming due to heterogeneity across the landscape over time and space. This study deals with the development of remote-sensing based empirical relationships for the estimation of ground-based LAI (LAIG using NDVI, modelled with and without atmospheric correction models for three irrigated crops (corn, wheat and rice grown in irrigated farms within Coleambally Irrigation Area (CIA which is located in southern Murray Darling basin, NSW in Australia. Extensive ground truthing campaigns were carried out to measure crop growth and to collect field samples of LAI using LAI- 2000 Plant Canopy Analyser and reflectance using CROPSCAN Multi Spectral Radiometer at several farms within the CIA. A Set of 12 cloud free Landsat 5 TM satellite images for the period of 2010-11 were downloaded and regression analysis was carried out to analyse the co-relationships between satellite and ground measured reflectance and to check the reliability of data sets for the crops. Among all the developed regression relationships between LAI and NDVI, the atmospheric correction process has significantly improved the relationship between LAI and NDVI for Landsat 5 TM images. The regression analysis also shows strong correlations for corn and wheat but weak correlations for rice which is currently being investigated.

  8. Development of a remote sensing-based rice yield forecasting model

    Energy Technology Data Exchange (ETDEWEB)

    Mosleh, M.K.; Hassan, Q.K.; Chowdhury, E.H.

    2016-11-01

    This study aimed to develop a remote sensing-based method for forecasting rice yield by considering vegetation greenness conditions during initial and peak greenness stages of the crop; and implemented for “boro” rice in Bangladeshi context. In this research, we used Moderate Resolution Imaging Spectroradiometer (MODIS)-derived two 16-day composite of normalized difference vegetation index (NDVI) images at 250 m spatial resolution acquired during the initial (January 1 to January 16) and peak greenness (March 23/24 to April 6/7 depending on leap year) stages in conjunction with secondary datasets (i.e., boro suitability map, and ground-based information) during 2007-2012 period. The method consisted of two components: (i) developing a model for delineating area under rice cultivation before harvesting; and (ii) forecasting rice yield as a function of NDVI. Our results demonstrated strong agreements between the model (i.e., MODIS-based) and ground-based area estimates during 2010-2012 period, i.e., coefficient of determination (R2); root mean square error (RMSE); and relative error (RE) in between 0.93 to 0.95; 30,519 to 37,451 ha; and ±10% respectively at the 23 district-levels. We also found good agreements between forecasted (i.e., MODIS-based) and ground-based yields during 2010-2012 period (R2 between 0.76 and 0.86; RMSE between 0.21 and 0.29 Mton/ha, and RE between -5.45% and 6.65%) at the 23 district-levels. We believe that our developments of forecasting the boro rice yield would be useful for the decision makers in addressing food security in Bangladesh. (Author)

  9. Force Rendering and its Evaluation of a Friction-Based Walking Sensation Display for a Seated User.

    Science.gov (United States)

    Kato, Ginga; Kuroda, Yoshihiro; Kiyokawa, Kiyoshi; Takemura, Haruo

    2018-04-01

    Most existing locomotion devices that represent the sensation of walking target a user who is actually performing a walking motion. Here, we attempted to represent the walking sensation, especially a kinesthetic sensation and advancing feeling (the sense of moving forward) while the user remains seated. To represent the walking sensation using a relatively simple device, we focused on the force rendering and its evaluation of the longitudinal friction force applied on the sole during walking. Based on the measurement of the friction force applied on the sole during actual walking, we developed a novel friction force display that can present the friction force without the influence of body weight. Using performance evaluation testing, we found that the proposed method can stably and rapidly display friction force. Also, we developed a virtual reality (VR) walk-through system that is able to present the friction force through the proposed device according to the avatar's walking motion in a virtual world. By evaluating the realism, we found that the proposed device can represent a more realistic advancing feeling than vibration feedback.

  10. Integration of Predictive Display and Aircraft Flight Control System

    Directory of Open Access Journals (Sweden)

    Efremov A.V.

    2017-01-01

    Full Text Available The synthesis of predictive display information and direct lift control system are considered for the path control tracking tasks (in particular landing task. The both solutions are based on pilot-vehicle system analysis and requirements to provide the highest accuracy and lowest pilot workload. The investigation was carried out for cases with and without time delay in aircraft dynamics. The efficiency of the both ways for the flying qualities improvement and their integration is tested by ground based simulation.

  11. Web-based ground loop supervision system for the TJ-II Stellarator

    International Nuclear Information System (INIS)

    Pena, A. de la; Lapayese, F.; Pacios, L.; Carrasco, R.

    2005-01-01

    To minimize electromagnetic interferences in diagnostic and control signals, and to guarantee safe operation of TJ-II, ground loops must be avoided. In order to meet this goal, the whole grounding system of the TJ-II was split into multiple single branches that are connected at a single earth point located near the TJ-II structure in the torus hall. A real-time ground loop supervision system (GLSS) has been designed, manufactured and tested by the TJ-II control group for detecting unintentional short circuits between isolated grounded parts. A web server running on the real-time operating system OS-9 provides remote access to the real-time ground loops measurement. Ground loops monitoring and different operation modes can be configured via any web browser. This paper gives the detailed design of the whole TJ-II ground loop supervision system and its results during its operation

  12. Web-based ground loop supervision system for the TJ-II Stellarator

    Energy Technology Data Exchange (ETDEWEB)

    Pena, A. de la [Asociacion EURATOM-CIEMAT Para Fusion, Avd. Complutense 22, 28040 Madrid (Spain)]. E-mail: a.delapena@ciemat.es; Lapayese, F. [Asociacion EURATOM-CIEMAT Para Fusion, Avd. Complutense 22, 28040 Madrid (Spain); Pacios, L. [Asociacion EURATOM-CIEMAT Para Fusion, Avd. Complutense 22, 28040 Madrid (Spain); Carrasco, R. [Asociacion EURATOM-CIEMAT Para Fusion, Avd. Complutense 22, 28040 Madrid (Spain)

    2005-11-15

    To minimize electromagnetic interferences in diagnostic and control signals, and to guarantee safe operation of TJ-II, ground loops must be avoided. In order to meet this goal, the whole grounding system of the TJ-II was split into multiple single branches that are connected at a single earth point located near the TJ-II structure in the torus hall. A real-time ground loop supervision system (GLSS) has been designed, manufactured and tested by the TJ-II control group for detecting unintentional short circuits between isolated grounded parts. A web server running on the real-time operating system OS-9 provides remote access to the real-time ground loops measurement. Ground loops monitoring and different operation modes can be configured via any web browser. This paper gives the detailed design of the whole TJ-II ground loop supervision system and its results during its operation.

  13. Color display and encryption with a plasmonic polarizing metamirror

    Directory of Open Access Journals (Sweden)

    Song Maowen

    2018-01-01

    Full Text Available Structural colors emerge when a particular wavelength range is filtered out from a broadband light source. It is regarded as a valuable platform for color display and digital imaging due to the benefits of environmental friendliness, higher visibility, and durability. However, current devices capable of generating colors are all based on direct transmission or reflection. Material loss, thick configuration, and the lack of tunability hinder their transition to practical applications. In this paper, a novel mechanism that generates high-purity colors by photon spin restoration on ultrashallow plasmonic grating is proposed. We fabricated the sample by interference lithography and experimentally observed full color display, tunable color logo imaging, and chromatic sensing. The unique combination of high efficiency, high-purity colors, tunable chromatic display, ultrathin structure, and friendliness for fabrication makes this design an easy way to bridge the gap between theoretical investigations and daily-life applications.

  14. Preliminary Effect of Synthetic Vision Systems Displays to Reduce Low-Visibility Loss of Control and Controlled Flight Into Terrain Accidents

    Science.gov (United States)

    Glaab, Louis J.; Takallu, Mohammad A.

    2002-01-01

    An experimental investigation was conducted to study the effectiveness of Synthetic Vision Systems (SVS) flight displays as a means of eliminating Low Visibility Loss of Control (LVLOC) and Controlled Flight Into Terrain (CFIT) accidents by low time general aviation (GA) pilots. A series of basic maneuvers were performed by 18 subject pilots during transition from Visual Meteorological Conditions (VMC) to Instrument Meteorological Conditions (IMC), with continued flight into IMC, employing a fixed-based flight simulator. A total of three display concepts were employed for this evaluation. One display concept, referred to as the Attitude Indicator (AI) replicated instrumentation common in today's General Aviation (GA) aircraft. The second display concept, referred to as the Electronic Attitude Indicator (EAI), featured an enlarged attitude indicator that was more representative of a glass display that also included advanced flight symbology, such as a velocity vector. The third concept, referred to as the SVS display, was identical to the EAI except that computer-generated terrain imagery replaced the conventional blue-sky/brown-ground of the EAI. Pilot performance parameters, pilot control inputs and physiological data were recorded for post-test analysis. Situation awareness (SA) and qualitative pilot comments were obtained through questionnaires and free-form interviews administered immediately after the experimental session. Initial pilot performance data were obtained by instructor pilot observations. Physiological data (skin temperature, heart rate, and muscle flexure) were also recorded. Preliminary results indicate that far less errors were committed when using the EAI and SVS displays than when using conventional instruments. The specific data example examined in this report illustrates the benefit from SVS displays to avoid massive loss of SA conditions. All pilots acknowledged the enhanced situation awareness provided by the SVS display concept. Levels of

  15. A Fluid Membrane-Based Soluble Ligand Display System for Live CellAssays

    Energy Technology Data Exchange (ETDEWEB)

    Nam, Jwa-Min; Nair, Pradeep N.; Neve, Richard M.; Gray, Joe W.; Groves, Jay T.

    2005-10-14

    Cell communication modulates numerous biological processes including proliferation, apoptosis, motility, invasion and differentiation. Correspondingly, there has been significant interest in the development of surface display strategies for the presentation of signaling molecules to living cells. This effort has primarily focused on naturally surface-bound ligands, such as extracellular matrix components and cell membranes. Soluble ligands (e.g. growth factors and cytokines) play an important role in intercellular communications, and their display in a surface-bound format would be of great utility in the design of array-based live cell assays. Recently, several cell microarray systems that display cDNA, RNAi, or small molecules in a surface array format were proven to be useful in accelerating high-throughput functional genetic studies and screening therapeutic agents. These surface display methods provide a flexible platform for the systematic, combinatorial investigation of genes and small molecules affecting cellular processes and phenotypes of interest. In an analogous sense, it would be an important advance if one could display soluble signaling ligands in a surface assay format that allows for systematic, patterned presentation of soluble ligands to live cells. Such a technique would make it possible to examine cellular phenotypes of interest in a parallel format with soluble signaling ligands as one of the display parameters. Herein we report a ligand-modified fluid supported lipid bilayer (SLB) assay system that can be used to functionally display soluble ligands to cells in situ (Figure 1A). By displaying soluble ligands on a SLB surface, both solution behavior (the ability to become locally enriched by reaction-diffusion processes) and solid behavior (the ability to control the spatial location of the ligands in an open system) could be combined. The method reported herein benefits from the naturally fluid state of the supported membrane, which allows

  16. Developing upconversion nanoparticle-based smart substrates for remote temperature sensing

    Science.gov (United States)

    Coker, Zachary; Marble, Kassie; Alkahtani, Masfer; Hemmer, Philip; Yakovlev, Vladislav V.

    2018-02-01

    Recent developments in understanding of nanomaterial behaviors and synthesis have led to their application across a wide range of commercial and scientific applications. Recent investigations span from applications in nanomedicine and the development of novel drug delivery systems to nanoelectronics and biosensors. In this study, we propose the application of a newly engineered temperature sensitive water-based bio-compatible core/shell up-conversion nanoparticle (UCNP) in the development of a smart substrate for remote temperature sensing. We developed this smart substrate by dispersing functionalized nanoparticles into a polymer solution and then spin-coating the solution onto one side of a microscope slide to form a thin film substrate layer of evenly dispersed nanoparticles. By using spin-coating to deposit the particle solution we both create a uniform surface for the substrate while simultaneously avoid undesired particle agglomeration. Through this investigation, we have determined the sensitivity and capabilities of this smart substrate and conclude that further development can lead to a greater range of applications for this type smart substrate and use in remote temperature sensing in conjunction with other microscopy and spectroscopy investigations.

  17. Long term landslide monitoring with Ground Based SAR

    Science.gov (United States)

    Monserrat, Oriol; Crosetto, Michele; Luzi, Guido; Gili, Josep; Moya, Jose; Corominas, Jordi

    2014-05-01

    In the last decade, Ground-Based (GBSAR) has proven to be a reliable microwave Remote Sensing technique in several application fields, especially for unstable slopes monitoring. GBSAR can provide displacement measurements over few squared kilometres areas and with a very high spatial and temporal resolution. This work is focused on the use of GBSAR technique for long term landslide monitoring based on a particular data acquisition configuration, which is called discontinuous GBSAR (D-GBSAR). In the most commonly used GBSAR configuration, the radar is left installed in situ, acquiring data periodically, e.g. every few minutes. Deformations are estimated by processing sets of GBSAR images acquired during several weeks or months, without moving the system. By contrast, in the D-GBSAR the radar is installed and dismounted at each measurement campaign, revisiting a given site periodically. This configuration is useful to monitor slow deformation phenomena. In this work, two alternative ways for exploiting the D-GBSAR technique will be presented: the DInSAR technique and the Amplitude based Technique. The former is based on the exploitation of the phase component of the acquired SAR images and it allows providing millimetric precision on the deformation estimates. However, this technique presents several limitations like the reduction of measurable points with an increase in the period of observation, the ambiguous nature of the phase measurements, and the influence of the atmospheric phase component that can make it non applicable in some cases, specially when working in natural environments. The second approach, that is based on the use of the amplitude component of GB-SAR images combined with a image matching technique, will allow the estimation of the displacements over specific targets avoiding two of the limitations commented above: the phase unwrapping and atmosphere contribution but reducing the deformation measurement precision. Two successful examples of D

  18. Research on Visualization of Ground Laser Radar Data Based on Osg

    Science.gov (United States)

    Huang, H.; Hu, C.; Zhang, F.; Xue, H.

    2018-04-01

    Three-dimensional (3D) laser scanning is a new advanced technology integrating light, machine, electricity, and computer technologies. It can conduct 3D scanning to the whole shape and form of space objects with high precision. With this technology, you can directly collect the point cloud data of a ground object and create the structure of it for rendering. People use excellent 3D rendering engine to optimize and display the 3D model in order to meet the higher requirements of real time realism rendering and the complexity of the scene. OpenSceneGraph (OSG) is an open source 3D graphics engine. Compared with the current mainstream 3D rendering engine, OSG is practical, economical, and easy to expand. Therefore, OSG is widely used in the fields of virtual simulation, virtual reality, science and engineering visualization. In this paper, a dynamic and interactive ground LiDAR data visualization platform is constructed based on the OSG and the cross-platform C++ application development framework Qt. In view of the point cloud data of .txt format and the triangulation network data file of .obj format, the functions of 3D laser point cloud and triangulation network data display are realized. It is proved by experiments that the platform is of strong practical value as it is easy to operate and provides good interaction.

  19. RESEARCH ON VISUALIZATION OF GROUND LASER RADAR DATA BASED ON OSG

    Directory of Open Access Journals (Sweden)

    H. Huang

    2018-04-01

    Full Text Available Three-dimensional (3D laser scanning is a new advanced technology integrating light, machine, electricity, and computer technologies. It can conduct 3D scanning to the whole shape and form of space objects with high precision. With this technology, you can directly collect the point cloud data of a ground object and create the structure of it for rendering. People use excellent 3D rendering engine to optimize and display the 3D model in order to meet the higher requirements of real time realism rendering and the complexity of the scene. OpenSceneGraph (OSG is an open source 3D graphics engine. Compared with the current mainstream 3D rendering engine, OSG is practical, economical, and easy to expand. Therefore, OSG is widely used in the fields of virtual simulation, virtual reality, science and engineering visualization. In this paper, a dynamic and interactive ground LiDAR data visualization platform is constructed based on the OSG and the cross-platform C++ application development framework Qt. In view of the point cloud data of .txt format and the triangulation network data file of .obj format, the functions of 3D laser point cloud and triangulation network data display are realized. It is proved by experiments that the platform is of strong practical value as it is easy to operate and provides good interaction.

  20. A Two-Stage Reconstruction Processor for Human Detection in Compressive Sensing CMOS Radar.

    Science.gov (United States)

    Tsao, Kuei-Chi; Lee, Ling; Chu, Ta-Shun; Huang, Yuan-Hao

    2018-04-05

    Complementary metal-oxide-semiconductor (CMOS) radar has recently gained much research attraction because small and low-power CMOS devices are very suitable for deploying sensing nodes in a low-power wireless sensing system. This study focuses on the signal processing of a wireless CMOS impulse radar system that can detect humans and objects in the home-care internet-of-things sensing system. The challenges of low-power CMOS radar systems are the weakness of human signals and the high computational complexity of the target detection algorithm. The compressive sensing-based detection algorithm can relax the computational costs by avoiding the utilization of matched filters and reducing the analog-to-digital converter bandwidth requirement. The orthogonal matching pursuit (OMP) is one of the popular signal reconstruction algorithms for compressive sensing radar; however, the complexity is still very high because the high resolution of human respiration leads to high-dimension signal reconstruction. Thus, this paper proposes a two-stage reconstruction algorithm for compressive sensing radar. The proposed algorithm not only has lower complexity than the OMP algorithm by 75% but also achieves better positioning performance than the OMP algorithm especially in noisy environments. This study also designed and implemented the algorithm by using Vertex-7 FPGA chip (Xilinx, San Jose, CA, USA). The proposed reconstruction processor can support the 256 × 13 real-time radar image display with a throughput of 28.2 frames per second.

  1. A Two-Stage Reconstruction Processor for Human Detection in Compressive Sensing CMOS Radar

    Directory of Open Access Journals (Sweden)

    Kuei-Chi Tsao

    2018-04-01

    Full Text Available Complementary metal-oxide-semiconductor (CMOS radar has recently gained much research attraction because small and low-power CMOS devices are very suitable for deploying sensing nodes in a low-power wireless sensing system. This study focuses on the signal processing of a wireless CMOS impulse radar system that can detect humans and objects in the home-care internet-of-things sensing system. The challenges of low-power CMOS radar systems are the weakness of human signals and the high computational complexity of the target detection algorithm. The compressive sensing-based detection algorithm can relax the computational costs by avoiding the utilization of matched filters and reducing the analog-to-digital converter bandwidth requirement. The orthogonal matching pursuit (OMP is one of the popular signal reconstruction algorithms for compressive sensing radar; however, the complexity is still very high because the high resolution of human respiration leads to high-dimension signal reconstruction. Thus, this paper proposes a two-stage reconstruction algorithm for compressive sensing radar. The proposed algorithm not only has lower complexity than the OMP algorithm by 75% but also achieves better positioning performance than the OMP algorithm especially in noisy environments. This study also designed and implemented the algorithm by using Vertex-7 FPGA chip (Xilinx, San Jose, CA, USA. The proposed reconstruction processor can support the 256 × 13 real-time radar image display with a throughput of 28.2 frames per second.

  2. Tamper indicating and sensing optical-based smart structures

    International Nuclear Information System (INIS)

    Sliva, P.; Anheier, N.C.; Gordon, N.R.; Simmons, K.L.; Stahl, K.A.; Undem, H.A.

    1995-05-01

    This paper has presented an overview of the type of optical-based structures that can be designed and constructed. These smart structures are capable of responding to their environment. The examples given represent a modest sampling of the complexity that can be achieved in both design and practice. Tamper-indicating containers and smart, sensing windows demonstrate just a few of the applications. We have shown that optical-based smart structures can be made multifunctional with the sensing built in. The next generation smart structure will combine the sensing functionality of these optical-based smart structures with other sensors such as piezoelectrics and electro-rheological fluids to not only be able to respond to the environment, but to adapt to it as well. An example of functionality in this regime would be a piezosensor that senses pressure changes (e.g., shock waves), which then causes an electro-rheological fluid to change viscosity. A fiber sensor located in or near the electro-rheological fluid senses the stiffness change and sends a signal through a feedback loop back to the piezosensor for additional adjustments to the electro-rheological fluid

  3. A ROOT based event display software for JUNO

    Science.gov (United States)

    You, Z.; Li, K.; Zhang, Y.; Zhu, J.; Lin, T.; Li, W.

    2018-02-01

    An event display software SERENA has been designed for the Jiangmen Underground Neutrino Observatory (JUNO). The software has been developed in the JUNO offline software system and is based on the ROOT display package EVE. It provides an essential tool to display detector and event data for better understanding of the processes in the detectors. The software has been widely used in JUNO detector optimization, simulation, reconstruction and physics study.

  4. A NDVI assisted remote sensing image adaptive scale segmentation method

    Science.gov (United States)

    Zhang, Hong; Shen, Jinxiang; Ma, Yanmei

    2018-03-01

    Multiscale segmentation of images can effectively form boundaries of different objects with different scales. However, for the remote sensing image which widely coverage with complicated ground objects, the number of suitable segmentation scales, and each of the scale size is still difficult to be accurately determined, which severely restricts the rapid information extraction of the remote sensing image. A great deal of experiments showed that the normalized difference vegetation index (NDVI) can effectively express the spectral characteristics of a variety of ground objects in remote sensing images. This paper presents a method using NDVI assisted adaptive segmentation of remote sensing images, which segment the local area by using NDVI similarity threshold to iteratively select segmentation scales. According to the different regions which consist of different targets, different segmentation scale boundaries could be created. The experimental results showed that the adaptive segmentation method based on NDVI can effectively create the objects boundaries for different ground objects of remote sensing images.

  5. Fusion of Satellite Multispectral Images Based on Ground-Penetrating Radar (GPR Data for the Investigation of Buried Concealed Archaeological Remains

    Directory of Open Access Journals (Sweden)

    Athos Agapiou

    2017-06-01

    Full Text Available The paper investigates the superficial layers of an archaeological landscape based on the integration of various remote sensing techniques. It is well known in the literature that shallow depths may be rich in archeological remains, which generate different signal responses depending on the applied technique. In this study three main technologies are examined, namely ground-penetrating radar (GPR, ground spectroscopy, and multispectral satellite imagery. The study aims to propose a methodology to enhance optical remote sensing satellite images, intended for archaeological research, based on the integration of ground based and satellite datasets. For this task, a regression model between the ground spectroradiometer and GPR is established which is then projected to a high resolution sub-meter optical image. The overall methodology consists of nine steps. Beyond the acquirement of the in-situ measurements and their calibration (Steps 1–3, various regression models are examined for more than 70 different vegetation indices (Steps 4–5. The specific data analysis indicated that the red-edge position (REP hyperspectral index was the most appropriate for developing a local fusion model between ground spectroscopy data and GPR datasets (Step 6, providing comparable results with the in situ GPR measurements (Step 7. Other vegetation indices, such as the normalized difference vegetation index (NDVI, have also been examined, providing significant correlation between the two datasets (R = 0.50. The model is then projected to a high-resolution image over the area of interest (Step 8. The proposed methodology was evaluated with a series of field data collected from the Vésztő-Mágor Tell in the eastern part of Hungary. The results were compared with in situ magnetic gradiometry measurements, indicating common interpretation results. The results were also compatible with the preliminary archaeological investigations of the area (Step 9. The overall

  6. GROPE-1: a computer display to the sense of feel

    Energy Technology Data Exchange (ETDEWEB)

    Batter, J J; Brooks, Jr, F P

    1972-01-01

    A computer display system was built and programmed that exerts programmable forces on the fingers as one moves a knob in a plane. The system includes a movable carriage, position sensors, mechanisms for converting computer outputs to forces, a visual graphic display, and, most important, the programs. A controlled experiment measured the utility of force output. Two groups were taught topics in elementary field theory and exercised with the computer displays. One group had force displayed to the hand as well as to the eye. The other had visual display only. The experiment was repeated with three different sets of students. The force-display groups performed significantly better in two of the three cases; in the third case, interest in the subject was low and this seems to account for low performance.

  7. Design of the task-based display prototype and the first user-test

    International Nuclear Information System (INIS)

    Svengren, Haakan; Strand, Stine

    2005-09-01

    This report provides a description of the Task-based displays prototype for BWRs, and documents the results of the first user-test. Three different kinds of Task-based displays were designed: 1) displays for performing first checks and obtaining overview in emergency situations, 2) displays for performing emergency procedures, and 3) displays that facilitate understanding of the process and logic. The procedures included an expert-help function to support the operators in performing the procedures. The design was only implemented on the reactor side of the plant. The user-test was conducted using the HAMBO simulator in HAMMLAB. 6 crews from Forsmark 3 and Oskarshamn 3 participated in the test. The crews participated in 4 scenarios, which all were considered as highly complex scenarios that included actuation of several reactor protection signals. The data collection techniques (questionnaires and interviews) intended to cover usability-related issues and mainly involved the reactor operators. The results demonstrated that the Task-based design approach was very well received by the operators, and that the work initiated by the design of this first prototype should be continued. The operators generally found the procedure-implementation and the displays useful and easy to understand. They considered the amount of information contained in the procedures and the displays as good, and associated with low levels of frustration. The expert-help provided in the current test was very premature. This resulted in somewhat poorer usability ratings compared to the procedures and the displays. However, the operators explicitly stated the usefulness of providing expert-help in the combination with computerized procedures. The operators rated the computer-based procedures as slightly easier, less time-consuming, and slightly less mentally demanding than paper-based procedures. All the operators considered navigation within and between the procedures as easy, although some

  8. SIRTA, a ground-based atmospheric observatory for cloud and aerosol research

    Directory of Open Access Journals (Sweden)

    M. Haeffelin

    2005-02-01

    Full Text Available Ground-based remote sensing observatories have a crucial role to play in providing data to improve our understanding of atmospheric processes, to test the performance of atmospheric models, and to develop new methods for future space-borne observations. Institut Pierre Simon Laplace, a French research institute in environmental sciences, created the Site Instrumental de Recherche par Télédétection Atmosphérique (SIRTA, an atmospheric observatory with these goals in mind. Today SIRTA, located 20km south of Paris, operates a suite a state-of-the-art active and passive remote sensing instruments dedicated to routine monitoring of cloud and aerosol properties, and key atmospheric parameters. Detailed description of the state of the atmospheric column is progressively archived and made accessible to the scientific community. This paper describes the SIRTA infrastructure and database, and provides an overview of the scientific research associated with the observatory. Researchers using SIRTA data conduct research on atmospheric processes involving complex interactions between clouds, aerosols and radiative and dynamic processes in the atmospheric column. Atmospheric modellers working with SIRTA observations develop new methods to test their models and innovative analyses to improve parametric representations of sub-grid processes that must be accounted for in the model. SIRTA provides the means to develop data interpretation tools for future active remote sensing missions in space (e.g. CloudSat and CALIPSO. SIRTA observation and research activities take place in networks of atmospheric observatories that allow scientists to access consistent data sets from diverse regions on the globe.

  9. Uav Positioning and Collision Avoidance Based on RSS Measurements

    Science.gov (United States)

    Masiero, A.; Fissore, F.; Guarnieri, A.; Pirotti, F.; Vettore, A.

    2015-08-01

    In recent years, Unmanned Aerial Vehicles (UAVs) are attracting more and more attention in both the research and industrial communities: indeed, the possibility to use them in a wide range of remote sensing applications makes them a very flexible and attractive solution in both civil and commercial cases (e.g. precision agriculture, security and control, monitoring of sites, exploration of areas difficult to reach). Most of the existing UAV positioning systems rely on the use of the GPS signal. Despite this can be a satisfactory solution in open environments where the GPS signal is available, there are several operating conditions of interest where it is unavailable or unreliable (e.g. close to high buildings, or mountains, in indoor environments). Consequently, a different approach has to be adopted in these cases. This paper considers the use ofWiFi measurements in order to obtain position estimations of the device of interest. More specifically, to limit the costs for the devices involved in the positioning operations, an approach based on radio signal strengths (RSS) measurements is considered. Thanks to the use of a Kalman filter, the proposed approach takes advantage of the temporal dynamic of the device of interest in order to improve the positioning results initially provided by means of maximum likelihood estimations. The considered UAVs are assumed to be provided with communication devices, which can allow them to communicate with each other in order to improve their cooperation abilities. In particular, the collision avoidance problem is examined in this work.

  10. Future of photorefractive based holographic 3D display

    Science.gov (United States)

    Blanche, P.-A.; Bablumian, A.; Voorakaranam, R.; Christenson, C.; Lemieux, D.; Thomas, J.; Norwood, R. A.; Yamamoto, M.; Peyghambarian, N.

    2010-02-01

    The very first demonstration of our refreshable holographic display based on photorefractive polymer was published in Nature early 20081. Based on the unique properties of a new organic photorefractive material and the holographic stereography technique, this display addressed a gap between large static holograms printed in permanent media (photopolymers) and small real time holographic systems like the MIT holovideo. Applications range from medical imaging to refreshable maps and advertisement. Here we are presenting several technical solutions for improving the performance parameters of the initial display from an optical point of view. Full color holograms can be generated thanks to angular multiplexing, the recording time can be reduced from minutes to seconds with a pulsed laser, and full parallax hologram can be recorded in a reasonable time thanks to parallel writing. We also discuss the future of such a display and the possibility of video rate.

  11. Cholesteric Liquid Crystal Based Reflex Color Reflective Displays

    Science.gov (United States)

    Khan, Asad

    2012-02-01

    Bistable color cholesteric liquid crystal displays are unique LCDs that exhibit high reflectivity, good contrast, extremely low power operation, and are amenable to versatile roll-to-roll manufacturing. The display technology, now branded as Reflex has been in commercialized products since 1996. It has been the subject of extensive research and development globally by a variety of parties in both academic and industrial settings. Today, the display technology is in volume production for applications such as dedicated eWriters (Boogie Board), full color electronic skins (eSkin), and displays for smart cards. The flexibility comes from polymerization induced phase separation using unique materials unparalleled in any other display technology. The blend of monomers, polymers, cross linkers, and other components along with nematic liquid crystals and chiral dopants is created and processed in such ways so as to enable highly efficient manufactrable displays using ultra thin plastic substrates -- often as thin as 50μm. Other significant aspects include full color by stacking or spatial separation, night vision capability, ultra high resolution, as well as active matrix capabilities. Of particular note is the stacking approach of Reflex based displays to show full color. This approach for reflective color displays is unique to this technology. Owing to high transparency in wavelength bands outside the selective reflection band, three primarily color layers can be stacked on top of each other and reflect without interfering with other layers. This highly surprising architecture enables the highest reflectivity of any other reflective electronic color display technology. The optics, architecture, electro-topics, and process techniques will be discussed. This presentation will focus on the physics of the core technology and color, it's evolution from rigid glass based displays to flexible displays, development of products from the paradigm shifting concepts to consumer

  12. Integrated ground-based hyperspectral imaging and geochemical study of the Eagle Ford Group in West Texas

    Science.gov (United States)

    Sun, Lei; Khan, Shuhab; Godet, Alexis

    2018-01-01

    This study used ground-based hyperspectral imaging to map an outcrop of the Eagle Ford Group in west Texas. The Eagle Ford Group consists of alternating layers of mudstone - wackestone, grainstone - packstone facies and volcanic ash deposits with high total organic content deposited during the Cenomanian - Turonian time period. It is one of the few unconventional source rock and reservoirs that have surface representations. Ground-based hyperspectral imaging scanned an outcrop and hand samples at close ranges with very fine spatial resolution (centimeter to sub-millimeter). Spectral absorption modeling of clay minerals and calcite with the modified Gaussian model (MGM) allowed quantification of variations of mineral abundances. Petrographic analysis confirmed mineral identifications and shed light on sedimentary textures, and major element geochemistry supported the mineral quantification. Mineral quantification resulted in mapping of mudstone - wackestone, grainstone - packstone facies and bentonites (volcanic ash beds). The lack of spatial associations between the grainstones and bentonites on the outcrop calls into question the hypothesis that the primary productivity is controlled by iron availability from volcanic ash beds. Enrichment of molybdenum (Mo) and uranium (U) indicated "unrestricted marine" paleo-hydrogeology and anoxic to euxinic paleo-redox bottom water conditions. Hyperspectral remote sensing data also helped in creating a virtual outcrop model with detailed mineralogical compositions, and provided reservoir analog to extract compositional and geo-mechanical characteristics and variations. The utilization of these new techniques in geo-statistical analysis provides a workflow for employing remote sensing in resource exploration and exploitation.

  13. Decision Support from Genetic Algorithms for Ship Collision Avoidance Route Planning and Alerts

    Science.gov (United States)

    Tsou, Ming-Cheng; Kao, Sheng-Long; Su, Chien-Min

    When an officer of the watch (OOW) faces complicated marine traffic, a suitable decision support tool could be employed in support of collision avoidance decisions, to reduce the burden and greatly improve the safety of marine traffic. Decisions on routes to avoid collisions could also consider economy as well as safety. Through simulating the biological evolution model, this research adopts the genetic algorithm used in artificial intelligence to find a theoretically safety-critical recommendation for the shortest route of collision avoidance from an economic viewpoint, combining the international regulations for preventing collisions at sea (COLREGS) and the safety domain of a ship. Based on this recommendation, an optimal safe avoidance turning angle, navigation restoration time and navigational restoration angle will also be provided. A Geographic Information System (GIS) will be used as the platform for display and operation. In order to achieve advance notice of alerts and due preparation for collision avoidance, a Vessel Traffic Services (VTS) operator and the OOW can use this system as a reference to assess collision avoidance at present location.

  14. Characterization of subarctic vegetation using ground based remote sensing methods

    Science.gov (United States)

    Finnell, D.; Garnello, A.; Palace, M. W.; Sullivan, F.; Herrick, C.; Anderson, S. M.; Crill, P. M.; Varner, R. K.

    2014-12-01

    Stordalen mire is located at 68°21'N and 19°02'E in the Swedish subarctic. Climate monitoring has revealed a warming trend spanning the past 150 years affecting the mires ability to hold stable palsa/hummock mounds. The micro-topography of the landscape has begun to degrade into thaw ponds changing the vegetation cover from ombrothrophic to minerotrophic. Hummocks are ecologically important due to their ability to act as a carbon sinks. Thaw ponds and sphagnum rich transitional zones have been documented as sources of atmospheric CH4. An objective of this project is to determine if a high resolution three band camera (RGB) and a RGNIR camera could detect differences in vegetation over five different site types. Species composition was collected for 50 plots with ten repetitions for each site type: palsa/hummock, tall shrub, semi-wet, tall graminoid, and wet. Sites were differentiated based on dominating species and features consisting of open water presence, sphagnum spp. cover, graminoid spp. cover, or the presence of dry raised plateaus/mounds. A pole based camera mount was used to collect images at a height of ~2.44m from the ground. The images were cropped in post-processing to fit a one-square meter quadrat. Texture analysis was performed on all images, including entropy, lacunarity, and angular second momentum. Preliminary results suggested that site type influences the number of species present. The p-values for the ability to predict site type using a t-test range from use of a stepwise regression of texture variables, actual vs. predicted percent of vegetation coverage provided R squared values of 0.73, 0.71, 0.67, and 0.89 for C. bigelowii, R. chamaemorus, Sphagnum spp., and open water respectively. These data have provided some support to the notion that texture analyses can be used for classification of mire site types. Future work will involve scaling up from the 50 plots through the use of data collected from two unmanned aerial systems (UAS), as

  15. Regional Analysis of Remote Sensing Based Evapotranspiration Information

    Science.gov (United States)

    Geli, H. M. E.; Hain, C.; Anderson, M. C.; Senay, G. B.

    2017-12-01

    Recent research findings on modeling actual evapotranspiration (ET) using remote sensing data and methods have proven the ability of these methods to address wide range of hydrological and water resources issues including river basin water balance for improved water resources management, drought monitoring, drought impact and socioeconomic responses, agricultural water management, optimization of land-use for water conservations, water allocation agreement among others. However, there is still a critical need to identify appropriate type of ET information that can address each of these issues. The current trend of increasing demand for water due to population growth coupled with variable and limited water supply due to drought especially in arid and semiarid regions with limited water supply have highlighted the need for such information. To properly address these issues different spatial and temporal resolutions of ET information will need to be used. For example, agricultural water management applications require ET information at field (30-m) and daily time scales while for river basin hydrologic analysis relatively coarser spatial and temporal scales can be adequate for such regional applications. The objective of this analysis is to evaluate the potential of using an integrated ET information that can be used to address some of these issues collectively. This analysis will highlight efforts to address some of the issues that are applicable to New Mexico including assessment of statewide water budget as well as drought impact and socioeconomic responses which all require ET information but at different spatial and temporal scales. This analysis will provide an evaluation of four remote sensing based ET models including ALEXI, DisALEXI, SSEBop, and SEBAL3.0. The models will be compared with ground-based observations from eddy covariance towers and water balance calculations. Remote sensing data from Landsat, MODIS, and VIIRS sensors will be used to provide ET

  16. Robust Initial Wetness Condition Framework of an Event-Based Rainfall–Runoff Model Using Remotely Sensed Soil Moisture

    Directory of Open Access Journals (Sweden)

    Wooyeon Sunwoo

    2017-01-01

    Full Text Available Runoff prediction in limited-data areas is vital for hydrological applications, such as the design of infrastructure and flood defenses, runoff forecasting, and water management. Rainfall–runoff models may be useful for simulation of runoff generation, particularly event-based models, which offer a practical modeling scheme because of their simplicity. However, there is a need to reduce the uncertainties related to the estimation of the initial wetness condition (IWC prior to a rainfall event. Soil moisture is one of the most important variables in rainfall–runoff modeling, and remotely sensed soil moisture is recognized as an effective way to improve the accuracy of runoff prediction. In this study, the IWC was evaluated based on remotely sensed soil moisture by using the Soil Conservation Service-Curve Number (SCS-CN method, which is one of the representative event-based models used for reducing the uncertainty of runoff prediction. Four proxy variables for the IWC were determined from the measurements of total rainfall depth (API5, ground-based soil moisture (SSMinsitu, remotely sensed surface soil moisture (SSM, and soil water index (SWI provided by the advanced scatterometer (ASCAT. To obtain a robust IWC framework, this study consists of two main parts: the validation of remotely sensed soil moisture, and the evaluation of runoff prediction using four proxy variables with a set of rainfall–runoff events in the East Asian monsoon region. The results showed an acceptable agreement between remotely sensed soil moisture (SSM and SWI and ground based soil moisture data (SSMinsitu. In the proxy variable analysis, the SWI indicated the optimal value among the proposed proxy variables. In the runoff prediction analysis considering various infiltration conditions, the SSM and SWI proxy variables significantly reduced the runoff prediction error as compared with API5 by 60% and 66%, respectively. Moreover, the proposed IWC framework with

  17. Quantitative Estimation of Above Ground Crop Biomass using Ground-based, Airborne and Spaceborne Low Frequency Polarimetric Synthetic Aperture Radar

    Science.gov (United States)

    Koyama, C.; Watanabe, M.; Shimada, M.

    2016-12-01

    Estimation of crop biomass is one of the important challenges in environmental remote sensing related to agricultural as well as hydrological and meteorological applications. Usually passive optical data (photographs, spectral data) operating in the visible and near-infrared bands is used for such purposes. The virtue of optical remote sensing for yield estimation, however, is rather limited as the visible light can only provide information about the chemical characteristics of the canopy surface. Low frequency microwave signals with wavelength longer 20 cm have the potential to penetrate through the canopy and provide information about the whole vertical structure of vegetation from the top of the canopy down to the very soil surface. This phenomenon has been well known and exploited to detect targets under vegetation in the military radar application known as FOPEN (foliage penetration). With the availability of polarimetric interferometric SAR data the use PolInSAR techniques to retrieve vertical vegetation structures has become an attractive tool. However, PolInSAR is still highly experimental and suitable data is not yet widely available. In this study we focus on the use of operational dual-polarization L-band (1.27 GHz) SAR which is since the launch of Japan's Advanced Land Observing Satellite (ALOS, 2006-2011) available worldwide. Since 2014 ALOS-2 continues to deliver such kind of partial polarimetric data for the entire land surface. In addition to these spaceborne data sets we use airborne L-band SAR data acquired by the Japanese Pi-SAR-L2 as well as ultra-wideband (UWB) ground based SAR data operating in the frequency range from 1-4 GHz. By exploiting the complex dual-polarization [C2] Covariance matrix information, the scattering contributions from the canopy can be well separated from the ground reflections allowing for the establishment of semi-empirical relationships between measured radar reflectivity and the amount of fresh-weight above-ground

  18. Graphite paper-based bipolar electrode electrochemiluminescence sensing platform.

    Science.gov (United States)

    Zhang, Xin; Ding, Shou-Nian

    2017-08-15

    In this work, aiming at the construction of a disposable, wireless, low-cost and sensitive system for bioassay, we report a closed bipolar electrode electrochemiluminescence (BPE-ECL) sensing platform based on graphite paper as BPE for the first time. Graphite paper is qualified as BPE due to its unique properties such as excellent electrical conductivity, uniform composition and ease of use. This simple BPE-ECL device was applied to the quantitative analysis of oxidant (H 2 O 2 ) and biomarker (CEA) respectively, according to the principle of BPE sensing-charge balance. For the H 2 O 2 analysis, Pt NPs were electrodeposited onto the cathode through a bipolar electrodeposition approach to promote the sensing performance. As a result, this BPE-ECL device exhibited a wide linear range of 0.001-15mM with a low detection limit of 0.5µM (S/N=3) for H 2 O 2 determination. For the determination of CEA, chitosan-multi-walled carbon nanotubes (CS-MWCNTs) were employed to supply a hydrophilic interface for immobilizing primary antibody (Ab 1 ); and Au@Pt nanostructures were conjugated with secondary antibody (Ab 2 ) as catalysts for H 2 O 2 reduction. Under the optimal conditions, the BPE-ECL immunodevice showed a wide linear range of 0.01-60ngmL -1 with a detection limit of 5.0pgmL -1 for CEA. Furthermore, it also displayed satisfactory selectivity, excellent stability and good reproducibility. The developed method opened a new avenue to clinical bioassay. Copyright © 2017 Elsevier B.V. All rights reserved.

  19. PREDICTIVE POTENTIAL FIELD-BASED COLLISION AVOIDANCE FOR MULTICOPTERS

    Directory of Open Access Journals (Sweden)

    M. Nieuwenhuisen

    2013-08-01

    Full Text Available Reliable obstacle avoidance is a key to navigating with UAVs in the close vicinity of static and dynamic obstacles. Wheel-based mobile robots are often equipped with 2D or 3D laser range finders that cover the 2D workspace sufficiently accurate and at a high rate. Micro UAV platforms operate in a 3D environment, but the restricted payload prohibits the use of fast state-of-the-art 3D sensors. Thus, perception of small obstacles is often only possible in the vicinity of the UAV and a fast collision avoidance system is necessary. We propose a reactive collision avoidance system based on artificial potential fields, that takes the special dynamics of UAVs into account by predicting the influence of obstacles on the estimated trajectory in the near future using a learned motion model. Experimental evaluation shows that the prediction leads to smoother trajectories and allows to navigate collision-free through passageways.

  20. A new approach to quantify and map carbon stored, sequestered and emissions avoided by urban forests

    Science.gov (United States)

    E. Gregory McPherson; Qingfu Xiao; Elena Aguaron

    2013-01-01

    This paper describes the use of field surveys, biometric information for urban tree species and remote sensing to quantify and map carbon (C) storage, sequestration and avoided emissions from energy savings. Its primary contribution is methodological; the derivation and application of urban tree canopy (UTC) based transfer functions (t C ha-1 UTC). Findings for Los...

  1. Ground and river water quality monitoring using a smartphone-based pH sensor

    Directory of Open Access Journals (Sweden)

    Sibasish Dutta

    2015-05-01

    Full Text Available We report here the working of a compact and handheld smartphone-based pH sensor for monitoring of ground and river water quality. Using simple laboratory optical components and the camera of the smartphone, we develop a compact spectrophotometer which is operational in the wavelength range of 400-700 nm and having spectral resolution of 0.305 nm/pixel for our equipment. The sensor measures variations in optical absorption band of pH sensitive dye sample in different pH solutions. The transmission image spectra through a transmission grating gets captured by the smartphone, and subsequently converted into intensity vs. wavelengths. Using the designed sensor, we measure water quality of ground water and river water from different locations in Assam and the results are found to be reliable when compared with the standard spectrophotometer tool. The overall cost involved for development of the sensor is relatively low. We envision that the designed sensing technique could emerge as an inexpensive, compact and portable pH sensor that would be useful for in-field applications.

  2. Properties of the Visible Light Phototaxis and UV Avoidance Behaviors in the Larval Zebrafish.

    Science.gov (United States)

    Guggiana-Nilo, Drago A; Engert, Florian

    2016-01-01

    For many organisms, color is an essential source of information from visual scenes. The larval zebrafish has the potential to be a model for the study of this topic, given its tetrachromatic retina and high dependence on vision. In this study we took a step toward understanding how the larval zebrafish might use color sensing. To this end, we used a projector-based paradigm to force a choice of a color stimulus at every turn of the larva. The stimuli used spanned most of the larval spectral range, including activation of its Ultraviolet (UV) cone, which has not been described behaviorally before. We found that zebrafish larvae swim toward visible wavelengths (>400 nm) when choosing between them and darkness, as has been reported with white light. However, when presented with UV light and darkness zebrafish show an intensity dependent avoidance behavior. This UV avoidance does not interact cooperatively with phototaxis toward longer wavelengths, but can compete against it in an intensity dependent manner. Finally, we show that the avoidance behavior depends on the presence of eyes with functional UV cones. These findings open future avenues for studying the neural circuits that underlie color sensing in the larval zebrafish.

  3. USING DISTANCE SENSORS TO PERFORM COLLISION AVOIDANCE MANEUVRES ON UAV APPLICATIONS

    Directory of Open Access Journals (Sweden)

    A. Raimundo

    2017-08-01

    Full Text Available The Unmanned Aerial Vehicles (UAV and its applications are growing for both civilian and military purposes. The operability of an UAV proved that some tasks and operations can be done easily and at a good cost-efficiency ratio. Nowadays, an UAV can perform autonomous missions. It is very useful to certain UAV applications, such as meteorology, vigilance systems, agriculture, environment mapping and search and rescue operations. One of the biggest problems that an UAV faces is the possibility of collision with other objects in the flight area. To avoid this, an algorithm was developed and implemented in order to prevent UAV collision with other objects. “Sense and Avoid” algorithm was developed as a system for UAVs to avoid objects in collision course. This algorithm uses a Light Detection and Ranging (LiDAR, to detect objects facing the UAV in mid-flights. This light sensor is connected to an on-board hardware, Pixhawk’s flight controller, which interfaces its communications with another hardware: Raspberry Pi. Communications between Ground Control Station and UAV are made via Wi-Fi or cellular third or fourth generation (3G/4G. Some tests were made in order to evaluate the “Sense and Avoid” algorithm’s overall performance. These tests were done in two different environments: A 3D simulated environment and a real outdoor environment. Both modes worked successfully on a simulated 3D environment, and “Brake” mode on a real outdoor, proving its concepts.

  4. Multi-source remote sensing data management system

    International Nuclear Information System (INIS)

    Qin Kai; Zhao Yingjun; Lu Donghua; Zhang Donghui; Wu Wenhuan

    2014-01-01

    In this thesis, the author explored multi-source management problems of remote sensing data. The main idea is to use the mosaic dataset model, and the ways of an integreted display of image and its interpretation. Based on ArcGIS and IMINT feature knowledge platform, the author used the C# and other programming tools for development work, so as to design and implement multi-source remote sensing data management system function module which is able to simply, conveniently and efficiently manage multi-source remote sensing data. (authors)

  5. Aircraft interrogation and display system: A ground support equipment for digital flight systems

    Science.gov (United States)

    Glover, R. D.

    1982-01-01

    A microprocessor-based general purpose ground support equipment for electronic systems was developed. The hardware and software are designed to permit diverse applications in support of aircraft flight systems and simulation facilities. The implementation of the hardware, the structure of the software, describes the application of the system to an ongoing research aircraft project are described.

  6. The effect of pyrazine odor on avoidance learning and memory in wild robins Erithacus rubecula

    Directory of Open Access Journals (Sweden)

    Emma C. SIDDALL, Nicola M. MARPLES

    2011-04-01

    Full Text Available Toxic insects advertise their defended state to potential predators using warning displays. Frequently these displays use cues through more than one sensory modality, and combine color, smell and sound to produce a multimodal warning display. Signalling through more than one sensory pathway may enhance the rate of avoidance learning, and the memorability of the learned avoidance. A common insect warning odor, pyrazine, has previously been shown to increase the rate of learned avoidance of unpalatable yellow prey by domestic chicks (Gallus gallus domesticus, and the odor also improved memory of this learned avoidance. However, to date no research has examined this response to pyrazine odor using wild birds under natural conditions. This study used wild robins (Erithacus rubecula to investigate whether wild birds avoided yellow baits that smelled of pyrazine more strongly than those presented with no odor. The results provide some evidence that pyrazine odor does increase the level of protection an aposematic insect gains from a wild avian predator, but that the effect of pyrazine on learned avoidance was much weaker than was found with domestic chicks [Current Zoology 57 (2: 208–214, 2011].

  7. Exploration of the Trade Space Between Unmanned Aircraft Systems Descent Maneuver Performance and Sense-and-Avoid System Performance Requirements

    Science.gov (United States)

    Jack, Devin P.; Hoffler, Keith D.; Johnson, Sally C.

    2014-01-01

    A need exists to safely integrate Unmanned Aircraft Systems (UAS) into the United States' National Airspace System. Replacing manned aircraft's see-and-avoid capability in the absence of an onboard pilot is one of the key challenges associated with safe integration. Sense-and-avoid (SAA) systems will have to achieve yet-to-be-determined required separation distances for a wide range of encounters. They will also need to account for the maneuver performance of the UAS they are paired with. The work described in this paper is aimed at developing an understanding of the trade space between UAS maneuver performance and SAA system performance requirements, focusing on a descent avoidance maneuver. An assessment of current manned and unmanned aircraft performance was used to establish potential UAS performance test matrix bounds. Then, near-term UAS integration work was used to narrow down the scope. A simulator was developed with sufficient fidelity to assess SAA system performance requirements. The simulator generates closest-point-of-approach (CPA) data from the wide range of UAS performance models maneuvering against a single intruder with various encounter geometries. Initial attempts to model the results made it clear that developing maneuver performance groups is required. Discussion of the performance groups developed and how to know in which group an aircraft belongs for a given flight condition and encounter is included. The groups are airplane, flight condition, and encounter specific, rather than airplane-only specific. Results and methodology for developing UAS maneuver performance requirements are presented for a descent avoidance maneuver. Results for the descent maneuver indicate that a minimum specific excess power magnitude can assure a minimum CPA for a given time-to-go prediction. However, smaller amounts of specific excess power may achieve or exceed the same CPA if the UAS has sufficient speed to trade for altitude. The results of this study will

  8. Neural Correlates of Auditory Figure-Ground Segregation Based on Temporal Coherence

    Science.gov (United States)

    Teki, Sundeep; Barascud, Nicolas; Picard, Samuel; Payne, Christopher; Griffiths, Timothy D.; Chait, Maria

    2016-01-01

    To make sense of natural acoustic environments, listeners must parse complex mixtures of sounds that vary in frequency, space, and time. Emerging work suggests that, in addition to the well-studied spectral cues for segregation, sensitivity to temporal coherence—the coincidence of sound elements in and across time—is also critical for the perceptual organization of acoustic scenes. Here, we examine pre-attentive, stimulus-driven neural processes underlying auditory figure-ground segregation using stimuli that capture the challenges of listening in complex scenes where segregation cannot be achieved based on spectral cues alone. Signals (“stochastic figure-ground”: SFG) comprised a sequence of brief broadband chords containing random pure tone components that vary from 1 chord to another. Occasional tone repetitions across chords are perceived as “figures” popping out of a stochastic “ground.” Magnetoencephalography (MEG) measurement in naïve, distracted, human subjects revealed robust evoked responses, commencing from about 150 ms after figure onset that reflect the emergence of the “figure” from the randomly varying “ground.” Neural sources underlying this bottom-up driven figure-ground segregation were localized to planum temporale, and the intraparietal sulcus, demonstrating that this area, outside the “classic” auditory system, is also involved in the early stages of auditory scene analysis.” PMID:27325682

  9. Vertical Jump Height Estimation Algorithm Based on Takeoff and Landing Identification Via Foot-Worn Inertial Sensing.

    Science.gov (United States)

    Wang, Jianren; Xu, Junkai; Shull, Peter B

    2018-03-01

    Vertical jump height is widely used for assessing motor development, functional ability, and motor capacity. Traditional methods for estimating vertical jump height rely on force plates or optical marker-based motion capture systems limiting assessment to people with access to specialized laboratories. Current wearable designs need to be attached to the skin or strapped to an appendage which can potentially be uncomfortable and inconvenient to use. This paper presents a novel algorithm for estimating vertical jump height based on foot-worn inertial sensors. Twenty healthy subjects performed countermovement jumping trials and maximum jump height was determined via inertial sensors located above the toe and under the heel and was compared with the gold standard maximum jump height estimation via optical marker-based motion capture. Average vertical jump height estimation errors from inertial sensing at the toe and heel were -2.2±2.1 cm and -0.4±3.8 cm, respectively. Vertical jump height estimation with the presented algorithm via inertial sensing showed excellent reliability at the toe (ICC(2,1)=0.98) and heel (ICC(2,1)=0.97). There was no significant bias in the inertial sensing at the toe, but proportional bias (b=1.22) and fixed bias (a=-10.23cm) were detected in inertial sensing at the heel. These results indicate that the presented algorithm could be applied to foot-worn inertial sensors to estimate maximum jump height enabling assessment outside of traditional laboratory settings, and to avoid bias errors, the toe may be a more suitable location for inertial sensor placement than the heel.

  10. Application of Decision Tree on Collision Avoidance System Design and Verification for Quadcopter

    Science.gov (United States)

    Chen, C.-W.; Hsieh, P.-H.; Lai, W.-H.

    2017-08-01

    The purpose of the research is to build a collision avoidance system with decision tree algorithm used for quadcopters. While the ultrasonic range finder judges the distance is in collision avoidance interval, the access will be replaced from operator to the system to control the altitude of the UAV. According to the former experiences on operating quadcopters, we can obtain the appropriate pitch angle. The UAS implement the following three motions to avoid collisions. Case1: initial slow avoidance stage, Case2: slow avoidance stage and Case3: Rapid avoidance stage. Then the training data of collision avoidance test will be transmitted to the ground station via wireless transmission module to further analysis. The entire decision tree algorithm of collision avoidance system, transmission data, and ground station have been verified in some flight tests. In the flight test, the quadcopter can implement avoidance motion in real-time and move away from obstacles steadily. In the avoidance area, the authority of the collision avoidance system is higher than the operator and implements the avoidance process. The quadcopter can successfully fly away from the obstacles in 1.92 meter per second and the minimum distance between the quadcopter and the obstacle is 1.05 meters.

  11. APPLICATION OF DECISION TREE ON COLLISION AVOIDANCE SYSTEM DESIGN AND VERIFICATION FOR QUADCOPTER

    Directory of Open Access Journals (Sweden)

    C.-W. Chen

    2017-08-01

    Full Text Available The purpose of the research is to build a collision avoidance system with decision tree algorithm used for quadcopters. While the ultrasonic range finder judges the distance is in collision avoidance interval, the access will be replaced from operator to the system to control the altitude of the UAV. According to the former experiences on operating quadcopters, we can obtain the appropriate pitch angle. The UAS implement the following three motions to avoid collisions. Case1: initial slow avoidance stage, Case2: slow avoidance stage and Case3: Rapid avoidance stage. Then the training data of collision avoidance test will be transmitted to the ground station via wireless transmission module to further analysis. The entire decision tree algorithm of collision avoidance system, transmission data, and ground station have been verified in some flight tests. In the flight test, the quadcopter can implement avoidance motion in real-time and move away from obstacles steadily. In the avoidance area, the authority of the collision avoidance system is higher than the operator and implements the avoidance process. The quadcopter can successfully fly away from the obstacles in 1.92 meter per second and the minimum distance between the quadcopter and the obstacle is 1.05 meters.

  12. Suborbital Reusable Launch Vehicles as an Opportunity to Consolidate and Calibrate Ground Based and Satellite Instruments

    Science.gov (United States)

    Papadopoulos, K.

    2014-12-01

    XCOR Aerospace, a commercial space company, is planning to provide frequent, low cost access to near-Earth space on the Lynx suborbital Reusable Launch Vehicle (sRLV). Measurements in the external vacuum environment can be made and can launch from most runways on a limited lead time. Lynx can operate as a platform to perform suborbital in situ measurements and remote sensing to supplement models and simulations with new data points. These measurements can serve as a quantitative link to existing instruments and be used as a basis to calibrate detectors on spacecraft. Easier access to suborbital data can improve the longevity and cohesiveness of spacecraft and ground-based resources. A study of how these measurements can be made on Lynx sRLV will be presented. At the boundary between terrestrial and space weather, measurements from instruments on Lynx can help develop algorithms to optimize the consolidation of ground and satellite based data as well as assimilate global models with new data points. For example, current tides and the equatorial electrojet, essential to understanding the Thermosphere-Ionosphere system, can be measured in situ frequently and on short notice. Furthermore, a negative-ion spectrometer and a Faraday cup, can take measurements of the D-region ion composition. A differential GPS receiver can infer the spatial gradient of ionospheric electron density. Instruments and optics on spacecraft degrade over time, leading to calibration drift. Lynx can be a cost effective platform for deploying a reference instrument to calibrate satellites with a frequent and fast turnaround and a successful return of the instrument. A calibrated reference instrument on Lynx can make collocated observations as another instrument and corrections are made for the latter, thus ensuring data consistency and mission longevity. Aboard a sRLV, atmospheric conditions that distort remotely sensed data (ground and spacecraft based) can be measured in situ. Moreover, an

  13. Matrix- based logic for avoiding paradoxes and its paraconsistent alternative

    Directory of Open Access Journals (Sweden)

    Paul Weingartner

    2011-06-01

    Full Text Available The present article shows that there are consistent and decidable many- valued systems of propositional logic which satisfy two or all the three criteria for non- trivial inconsistent theories by da Costa (1974. The weaker one of these paraconsistent system is also able to avoid a series of paradoxes which come up when classical logic is applied to empirical sciences. These paraconsistent systems are based on a 6- valued system of propositional logic for avoiding difficulties in several domains of empirical science (Weingartner (2009.

  14. Space and Ground-Based Infrastructures

    Science.gov (United States)

    Weems, Jon; Zell, Martin

    This chapter deals first with the main characteristics of the space environment, outside and inside a spacecraft. Then the space and space-related (ground-based) infrastructures are described. The most important infrastructure is the International Space Station, which holds many European facilities (for instance the European Columbus Laboratory). Some of them, such as the Columbus External Payload Facility, are located outside the ISS to benefit from external space conditions. There is only one other example of orbital platforms, the Russian Foton/Bion Recoverable Orbital Capsule. In contrast, non-orbital weightless research platforms, although limited in experimental time, are more numerous: sounding rockets, parabolic flight aircraft, drop towers and high-altitude balloons. In addition to these facilities, there are a number of ground-based facilities and space simulators, for both life sciences (for instance: bed rest, clinostats) and physical sciences (for instance: magnetic compensation of gravity). Hypergravity can also be provided by human and non-human centrifuges.

  15. LightForce Photon-Pressure Collision Avoidance: Efficiency Assessment on an Entire Catalogue of Space Debris

    Science.gov (United States)

    Stupl, Jan Michael; Faber, Nicolas; Foster, Cyrus; Yang Yang, Fan; Levit, Creon

    2013-01-01

    The potential to perturb debris orbits using photon pressure from ground-based lasers has been confirmed by independent research teams. Two useful applications of this scheme are protecting space assets from impacts with debris and stabilizing the orbital debris environment, both relying on collision avoidance rather than de-orbiting debris. This paper presents the results of a new assessment method to analyze the efficiency of the concept for collision avoidance. Earlier research concluded that one ground based system consisting of a 10 kW class laser, directed by a 1.5 m telescope with adaptive optics, can prevent a significant fraction of debris-debris collisions in low Earth orbit. That research used in-track displacement to measure efficiency and restricted itself to an analysis of a limited number of objects. As orbit prediction error is dependent on debris object properties, a static displacement threshold should be complemented with another measure to assess the efficiency of the scheme. In this paper we present the results of an approach using probability of collision. Using a least-squares fitting method, we improve the quality of the original TLE catalogue in terms of state and co-state accuracy. We then calculate collision probabilities for all the objects in the catalogue. The conjunctions with the highest risk of collision are then engaged by a simulated network of laser ground stations. After those engagements, the perturbed orbits are used to re-assess the collision probability in a 20 minute window around the original conjunction. We then use different criteria to evaluate the utility of the laser-based collision avoidance scheme and assess the number of base-line ground stations needed to mitigate a significant number of high probability conjunctions. Finally, we also give an account how a laser ground station can be used for both orbit deflection and debris tracking.

  16. An Ecological Approach to the Design of UAV Ground Control Station (GCS) Status Displays

    Science.gov (United States)

    Dowell, Susan; Morphew, Ephimia; Shively, Jay

    2003-01-01

    Use of UAVs in military and commercial applications will continue to increase. However, there has been limited research devoted to UAV GCS design. The current study employed an ecological approach to interfac e design. Ecological Interface Design (EID) can be characterized as r epresenting the properties of a system, such that an operator is enco uraged to use skill-based behavior when problem solving. When more ef fortful cognitive processes become necessary due to unfamiliar situations, the application of EID philosophy supports the application of kn owledge-based behavior. With advances toward multiple UAV command and control, operators need GCS interfaces designed to support understan ding of complex systems. We hypothesized that use of EID principles f or the display of UAV status information would result in better opera tor performance and situational awareness, while decreasing workload. Pilots flew a series of missions with three UAV GCS displays of statu s information (Alphanumeric, Ecological, and Hybrid display format). Measures of task performance, Situational Awareness, and workload dem onstrated the benefits of using an ecological approach to designing U AV GCS displays. The application of ecological principles to the design of UAV GCSs is a promising area for improving UAV operations.

  17. LandSense: A Citizen Observatory and Innovation Marketplace for Land Use and Land Cover Monitoring

    Science.gov (United States)

    Moorthy, Inian; Fritz, Steffen; See, Linda; McCallum, Ian

    2017-04-01

    Currently within the EU's Earth Observation (EO) monitoring framework, there is a need for low-cost methods for acquiring high quality in-situ data to create accurate and well-validated environmental monitoring products. To help address this need, a new four year Horizon 2020 project entitled LandSense will link remote sensing data with modern participatory data collection methods that involve citizen scientists. This paper will describe the citizen science activities within the LandSense Observatory that aim to deliver concrete, measurable and quality-assured ground-based data that will complement existing satellite monitoring systems. LandSense will deploy advanced tools, services and resources to mobilize and engage citizens to collect in-situ observations (i.e. ground-based data and visual interpretations of EO imagery). Integrating these citizen-driven in-situ data collections with established authoritative and open access data sources will help reduce costs, extend GEOSS and Copernicus capacities, and support comprehensive environmental monitoring systems. Policy-relevant campaigns will be implemented in close collaboration with multiple stakeholders to ensure that citizen observations address user requirements and contribute to EU-wide environmental governance and decision-making. Campaigns for addressing local and regional Land Use and Land Cover (LULC) issues are planned for select areas in Austria, France, Germany, Spain, Slovenia and Serbia. Novel LandSense services (LandSense Campaigner, FarmLand Support, Change Detector and Quality Assurance & Control) will be deployed and tested in these areas to address critical LULC issues (i.e. urbanization, agricultural land use and forest/habitat monitoring). For example, local residents in the cities of Vienna, Tulln, and Heidelberg will help cooperatively detect and map changes in land cover and green space to address key issues of urban sprawl, land take and flooding. Such campaigns are facilitated through

  18. Monitoring of Gangotri glacier using remote sensing and ground ...

    Indian Academy of Sciences (India)

    Dozier J 1989a Remote sensing of snow in the visible and near-infrared wavelengths; In: Theory and Applications of. Optical Remote Sensing (ed.) Asrar G (New York: John. Wiley and Sons), pp. 527–547. Dozier J 1989b Spectral signature of alpine snow cover from the Landsat Thematic Mapper; Rem. Sens. Environ. 28.

  19. Distal Communication by Chimpanzees (Pan troglodytes): Evidence for Common Ground?

    Science.gov (United States)

    Leavens, David A; Reamer, Lisa A; Mareno, Mary Catherine; Russell, Jamie L; Wilson, Daniel; Schapiro, Steven J; Hopkins, William D

    2015-01-01

    van der Goot et al. (2014) proposed that distal, deictic communication indexed the appreciation of the psychological state of a common ground between a signaler and a receiver. In their study, great apes did not signal distally, which they construed as evidence for the human uniqueness of a sense of common ground. This study exposed 166 chimpanzees to food and an experimenter, at an angular displacement, to ask, "Do chimpanzees display distal communication?" Apes were categorized as (a) proximal or (b) distal signalers on each of four trials. The number of chimpanzees who communicated proximally did not statistically differ from the number who signaled distally. Therefore, contrary to the claim by van der Goot et al., apes do communicate distally. © 2015 The Authors. Child Development © 2015 Society for Research in Child Development, Inc.

  20. Aerodynamic Drag Analysis of 3-DOF Flex-Gimbal GyroWheel System in the Sense of Ground Test

    Science.gov (United States)

    Huo, Xin; Feng, Sizhao; Liu, Kangzhi; Wang, Libin; Chen, Weishan

    2016-01-01

    GyroWheel is an innovative device that combines the actuating capabilities of a control moment gyro with the rate sensing capabilities of a tuned rotor gyro by using a spinning flex-gimbal system. However, in the process of the ground test, the existence of aerodynamic disturbance is inevitable, which hinders the improvement of the specification performance and control accuracy. A vacuum tank test is a possible candidate but is sometimes unrealistic due to the substantial increase in costs and complexity involved. In this paper, the aerodynamic drag problem with respect to the 3-DOF flex-gimbal GyroWheel system is investigated by simulation analysis and experimental verification. Concretely, the angular momentum envelope property of the spinning rotor system is studied and its integral dynamical model is deduced based on the physical configuration of the GyroWheel system with an appropriately defined coordinate system. In the sequel, the fluid numerical model is established and the model geometries are checked with FLUENT software. According to the diversity and time-varying properties of the rotor motions in three-dimensions, the airflow field around the GyroWheel rotor is analyzed by simulation with respect to its varying angular velocity and tilt angle. The IPC-based experimental platform is introduced, and the properties of aerodynamic drag in the ground test condition are obtained through comparing the simulation with experimental results. PMID:27941602

  1. Continuous monitoring of a mountain snowpack in the Austrian Alps by above-ground neutron sensing

    Science.gov (United States)

    Schattan, Paul; Baroni, Gabriele; Oswald, Sascha E.; Schöber, Johannes; Fey, Christine; Francke, Till; Huttenlau, Matthias; Achleitner, Stefan

    2017-04-01

    In alpine catchments the knowledge of the spatially and temporally heterogeneous dynamics of snow accumulation and depletion is crucial for modelling and managing water resources. While snow covered area can be retrieved operationally from remote sensing data, continuous measurements of other snow state variables like snow depth (SD) or snow water equivalent (SWE) remain challenging. Existing methods of retrieving both variables in alpine terrain face severe issues like a lack of spatial representativeness, labour-intensity or discontinuity in time. Recently, promising new measurement techniques combining a larger support with low maintenance cost like above-ground gamma-ray scintillators, GPS interferometric reflectometry or above-ground cosmic-ray neutron sensors (CRNS) have been suggested. While CRNS has proven its potential for monitoring soil moisture in a wide range of environments and applications, the empirical knowledge of using CRNS for snowpack monitoring is still very limited and restricted to shallow snowpacks with rather uniform evolution. The characteristics of an above-ground cosmic-ray neutron sensor (CRNS) were therefore evaluated for monitoring a mountain snowpack in the Austrian Alps (Kaunertal, Tyrol) during three winter seasons. The measurement campaign included a number of measurements during the period from 03/2014 to 06/2016: (i) neutron count measurements by CRNS, (ii) continuous point-scale SD and SWE measurements from an automatic weather station and (iii) 17 Terrestrial Laser Scanning (TLS) with simultaneous SD and SWE surveys. The highest accumulation in terms of SWE was found in 04/2014 with 600 mm. Neutron counts were compared to all available snow data. While previous studies suggested a signal saturation at around 100 mm of SWE, no complete signal saturation was found. A strong non-linear relation was found for both SD and SWE with best fits for spatially distributed TLS based snow data. Initially slightly different shapes were

  2. Making Sense of Low Back Pain and Pain-Related Fear.

    Science.gov (United States)

    Bunzli, Samantha; Smith, Anne; Schütze, Robert; Lin, Ivan; O'Sullivan, Peter

    2017-09-01

    Synopsis Pain-related fear is implicated in the transition from acute to chronic low back pain and the persistence of disabling low back pain, making it a key target for physical therapy intervention. The current understanding of pain-related fear is that it is a psychopathological problem, whereby people who catastrophize about the meaning of pain become trapped in a vicious cycle of avoidance behavior, pain, and disability, as recognized in the fear-avoidance model. However, there is evidence that pain-related fear can also be seen as a common-sense response to deal with low back pain, for example, when one is told that one's back is vulnerable, degenerating, or damaged. In this instance, avoidance is a common-sense response to protect a "damaged" back. While the fear-avoidance model proposes that when someone first develops low back pain, the confrontation of normal activity in the absence of catastrophizing leads to recovery, the pathway to recovery for individuals trapped in the fear-avoidance cycle is less clear. Understanding pain-related fear from a common-sense perspective enables physical therapists to offer individuals with low back pain and high fear a pathway to recovery by altering how they make sense of their pain. Drawing on a body of published work exploring the lived experience of pain-related fear in people with low back pain, this clinical commentary illustrates how Leventhal's common-sense model may assist physical therapists to understand the broader sense-making processes involved in the fear-avoidance cycle, and how they can be altered to facilitate fear reduction by applying strategies established in the behavioral medicine literature. J Orthop Sports Phys Ther 2017;47(9):628-636. Epub 13 Jul 2017. doi:10.2519/jospt.2017.7434.

  3. Visual merchandising window display

    Directory of Open Access Journals (Sweden)

    Opris (Cas. Stanila M.

    2013-12-01

    Full Text Available Window display plays a major part in the selling strategies; it does not only include the simple display of goods, nowadays it is a form of art, also having the purpose of sustaining the brand image. This article wants to reveal the tools that are essential in creating a fabulous window display. Being a window designer is not an easy job, you have to always think ahead trends, to have a sense of colour, to know how to use light to attract customers in the store after only one glance at the window. The big store window displays are theatre scenes: with expensive backgrounds, special effects and high fashion mannequins. The final role of the displays is to convince customers to enter the store and trigger the purchasing act which is the final goal of the retail activity.

  4. Evaluation of inorganic and organic light-emitting diode displays for signage application

    Science.gov (United States)

    Sharma, Pratibha; Kwok, Harry

    2006-08-01

    High-brightness, inorganic light-emitting diodes (LEDs) have been successfully utilized for edge-lighting of large displays for signage. Further interest in solid-state lighting technology has been fueled with the emergence of small molecule and polymer-based organic light-emitting diodes (OLEDs). In this paper, edgelit inorganic LED-based displays and state-of-the-art OLED-based displays are evaluated on the basis of electrical and photometric measurements. The reference size for a signage system is assumed to be 600 mm x 600mm based on the industrial usage. With the availability of high power light-emitting diodes, it is possible to develop edgelit signage systems of the standard size. These displays possess an efficacy of 18 lm/W. Although, these displays are environmentally friendly and efficient, they suffer from some inherent limitations. Homogeneity of displays, which is a prime requirement for illuminated signs, is not accomplished. A standard deviation of 3.12 lux is observed between the illuminance values on the surface of the display. In order to distribute light effectively, reflective gratings are employed. Reflective gratings aid in reducing the problem but fail to eliminate it. In addition, the overall cost of signage is increased by 50% with the use of these additional components. This problem can be overcome by the use of a distributed source of light. Hence, the organic-LEDs are considered as a possible contender. In this paper, we experimentally determine the feasibility of using OLEDs for signage applications and compare their performance with inorganic LEDs. Passive matrix, small-molecule based, commercially available OLEDs is used. Design techniques for implementation of displays using organic LEDs are also discussed. It is determined that tiled displays based on organic LEDs possess better uniformity than the inorganic LED-based displays. However, the currently available OLEDs have lower light-conversion efficiency and higher costs than the

  5. Range Sensor-Based Efficient Obstacle Avoidance through Selective Decision-Making.

    Science.gov (United States)

    Shim, Youngbo; Kim, Gon-Woo

    2018-03-29

    In this paper, we address a collision avoidance method for mobile robots. Many conventional obstacle avoidance methods have been focused solely on avoiding obstacles. However, this can cause instability when passing through a narrow passage, and can also generate zig-zag motions. We define two strategies for obstacle avoidance, known as Entry mode and Bypass mode. Entry mode is a pattern for passing through the gap between obstacles, while Bypass mode is a pattern for making a detour around obstacles safely. With these two modes, we propose an efficient obstacle avoidance method based on the Expanded Guide Circle (EGC) method with selective decision-making. The simulation and experiment results show the validity of the proposed method.

  6. Range Sensor-Based Efficient Obstacle Avoidance through Selective Decision-Making

    Directory of Open Access Journals (Sweden)

    Youngbo Shim

    2018-03-01

    Full Text Available In this paper, we address a collision avoidance method for mobile robots. Many conventional obstacle avoidance methods have been focused solely on avoiding obstacles. However, this can cause instability when passing through a narrow passage, and can also generate zig-zag motions. We define two strategies for obstacle avoidance, known as Entry mode and Bypass mode. Entry mode is a pattern for passing through the gap between obstacles, while Bypass mode is a pattern for making a detour around obstacles safely. With these two modes, we propose an efficient obstacle avoidance method based on the Expanded Guide Circle (EGC method with selective decision-making. The simulation and experiment results show the validity of the proposed method.

  7. Eigenvector Spatial Filtering Regression Modeling of Ground PM2.5 Concentrations Using Remotely Sensed Data

    Directory of Open Access Journals (Sweden)

    Jingyi Zhang

    2018-06-01

    Full Text Available This paper proposes a regression model using the Eigenvector Spatial Filtering (ESF method to estimate ground PM2.5 concentrations. Covariates are derived from remotely sensed data including aerosol optical depth, normal differential vegetation index, surface temperature, air pressure, relative humidity, height of planetary boundary layer and digital elevation model. In addition, cultural variables such as factory densities and road densities are also used in the model. With the Yangtze River Delta region as the study area, we constructed ESF-based Regression (ESFR models at different time scales, using data for the period between December 2015 and November 2016. We found that the ESFR models effectively filtered spatial autocorrelation in the OLS residuals and resulted in increases in the goodness-of-fit metrics as well as reductions in residual standard errors and cross-validation errors, compared to the classic OLS models. The annual ESFR model explained 70% of the variability in PM2.5 concentrations, 16.7% more than the non-spatial OLS model. With the ESFR models, we performed detail analyses on the spatial and temporal distributions of PM2.5 concentrations in the study area. The model predictions are lower than ground observations but match the general trend. The experiment shows that ESFR provides a promising approach to PM2.5 analysis and prediction.

  8. Eigenvector Spatial Filtering Regression Modeling of Ground PM2.5 Concentrations Using Remotely Sensed Data.

    Science.gov (United States)

    Zhang, Jingyi; Li, Bin; Chen, Yumin; Chen, Meijie; Fang, Tao; Liu, Yongfeng

    2018-06-11

    This paper proposes a regression model using the Eigenvector Spatial Filtering (ESF) method to estimate ground PM 2.5 concentrations. Covariates are derived from remotely sensed data including aerosol optical depth, normal differential vegetation index, surface temperature, air pressure, relative humidity, height of planetary boundary layer and digital elevation model. In addition, cultural variables such as factory densities and road densities are also used in the model. With the Yangtze River Delta region as the study area, we constructed ESF-based Regression (ESFR) models at different time scales, using data for the period between December 2015 and November 2016. We found that the ESFR models effectively filtered spatial autocorrelation in the OLS residuals and resulted in increases in the goodness-of-fit metrics as well as reductions in residual standard errors and cross-validation errors, compared to the classic OLS models. The annual ESFR model explained 70% of the variability in PM 2.5 concentrations, 16.7% more than the non-spatial OLS model. With the ESFR models, we performed detail analyses on the spatial and temporal distributions of PM 2.5 concentrations in the study area. The model predictions are lower than ground observations but match the general trend. The experiment shows that ESFR provides a promising approach to PM 2.5 analysis and prediction.

  9. Coordinated Ground-Based Observations and the New Horizons Fly-by of Pluto

    Science.gov (United States)

    Young, Eliot; Young, Leslie; Parker, Joel; Binzel, Richard

    2015-04-01

    The New Horizons (NH) spacecraft is scheduled to make its closest approach to Pluto on July 14, 2015. NH carries seven scientific instruments, including separate UV and Visible-IR spectrographs, a long-focal-length imager, two plasma-sensing instruments and a dust counter. There are three arenas in particular in which ground-based observations should augment the NH instrument suite in synergistic ways: IR spectra at wavelengths longer than 2.5 µm (i.e., longer than the NH Ralph spectrograph), stellar occultation observations near the time of the fly-by, and thermal surface maps and atmospheric CO abundances based on ALMA observations - we discuss the first two of these. IR spectra in the 3 - 5 µm range cover the CH4 absorption band near 3.3 µm. This band can be an important constraint on the state and areal extent of nitrogen frost on Pluto's surface. If this band depth is close to zero (as was observed by Olkin et al. 2007), it limits the area of nitrogen frost, which is bright at that wavelength. Combined with the NH observations of nitrogen frost at 2.15 µm, the ground-based spectra will determine how much nitrogen frost is diluted with methane, which is a basic constraint on the seasonal cycle of sublimation and condensation that takes place on Pluto (and similar objects like Triton and Eris). There is a fortuitous stellar occultation by Pluto on 29-JUN-2015, only two weeks before the NH closest approach. The occulted star will be the brightest ever observed in a Pluto event, about 2 magnitudes brighter than Pluto itself. The track of the event is predicted to cover parts of Australia and New Zealand. Thanks to HST and ground based campaigns to find a TNO target reachable by NH, the position of the shadow path will be known at the +/-100 km level, allowing SOFIA and mobile ground-based observers to reliably cover the central flash region. Ground-based & SOFIA observations in visible and IR wavelengths will characterize the haze opacity and vertical

  10. Study of the relations between cloud properties and atmospheric conditions using ground-based digital images

    Science.gov (United States)

    Bakalova, Kalinka

    The aerosol constituents of the earth atmosphere are of great significance for the radiation budget and global climate of the planet. They are the precursors of clouds that in turn play an essential role in these processes and in the hydrological cycle of the Earth. Understanding the complex aerosol-cloud interactions requires a detailed knowledge of the dynamical processes moving the water vapor through the atmosphere, and of the physical mechanisms involved in the formation and growth of cloud particles. Ground-based observations on regional and short time scale provide valuable detailed information about atmospheric dynamics and cloud properties, and are used as a complementary tool to the global satellite observations. The objective of the present paper is to study the physical properties of clouds as displayed in ground-based visible images, and juxtapose them to the specific surface and atmospheric meteorological conditions. The observations are being carried out over the urban area of the city of Sofia, Bulgaria. The data obtained from visible images of clouds enable a quantitative description of texture and morphological features of clouds such as shape, thickness, motion, etc. These characteristics are related to cloud microphysical properties. The changes of relative humidity and the horizontal visibility are considered to be representative of the variations of the type (natural/manmade) and amount of the atmospheric aerosols near the earth surface, and potentially, the cloud drop number concentration. The atmospheric dynamics is accounted for by means of the values of the atmospheric pressure, temperature, wind velocity, etc., observed at the earth's surface. The advantage of ground-based observations of clouds compared to satellite ones is in the high spatial and temporal resolution of the obtained data about the lowermost cloud layer, which in turn is sensitive to the meteorological regimes that determine cloud formation and evolution. It turns out

  11. Soil water content and evaporation determined by thermal parameters obtained from ground-based and remote measurements

    Science.gov (United States)

    Reginato, R. J.; Idso, S. B.; Jackson, R. D.; Vedder, J. F.; Blanchard, M. B.; Goettelman, R.

    1976-01-01

    Soil water contents from both smooth and rough bare soil were estimated from remotely sensed surface soil and air temperatures. An inverse relationship between two thermal parameters and gravimetric soil water content was found for Avondale loam when its water content was between air-dry and field capacity. These parameters, daily maximum minus minimum surface soil temperature and daily maximum soil minus air temperature, appear to describe the relationship reasonably well. These two parameters also describe relative soil water evaporation (actual/potential). Surface soil temperatures showed good agreement among three measurement techniques: in situ thermocouples, a ground-based infrared radiation thermometer, and the thermal infrared band of an airborne multispectral scanner.

  12. Linking Individual Learning Styles to Approach-Avoidance Motivational Traits and Computational Aspects of Reinforcement Learning.

    Directory of Open Access Journals (Sweden)

    Kristoffer Carl Aberg

    Full Text Available Learning how to gain rewards (approach learning and avoid punishments (avoidance learning is fundamental for everyday life. While individual differences in approach and avoidance learning styles have been related to genetics and aging, the contribution of personality factors, such as traits, remains undetermined. Moreover, little is known about the computational mechanisms mediating differences in learning styles. Here, we used a probabilistic selection task with positive and negative feedbacks, in combination with computational modelling, to show that individuals displaying better approach (vs. avoidance learning scored higher on measures of approach (vs. avoidance trait motivation, but, paradoxically, also displayed reduced learning speed following positive (vs. negative outcomes. These data suggest that learning different types of information depend on associated reward values and internal motivational drives, possibly determined by personality traits.

  13. Linking Individual Learning Styles to Approach-Avoidance Motivational Traits and Computational Aspects of Reinforcement Learning

    Science.gov (United States)

    Carl Aberg, Kristoffer; Doell, Kimberly C.; Schwartz, Sophie

    2016-01-01

    Learning how to gain rewards (approach learning) and avoid punishments (avoidance learning) is fundamental for everyday life. While individual differences in approach and avoidance learning styles have been related to genetics and aging, the contribution of personality factors, such as traits, remains undetermined. Moreover, little is known about the computational mechanisms mediating differences in learning styles. Here, we used a probabilistic selection task with positive and negative feedbacks, in combination with computational modelling, to show that individuals displaying better approach (vs. avoidance) learning scored higher on measures of approach (vs. avoidance) trait motivation, but, paradoxically, also displayed reduced learning speed following positive (vs. negative) outcomes. These data suggest that learning different types of information depend on associated reward values and internal motivational drives, possibly determined by personality traits. PMID:27851807

  14. Ground-based remote sensing of HDO/H2O ratio profiles: introduction and validation of an innovative retrieval approach

    Science.gov (United States)

    Schneider, M.; Hase, F.; Blumenstock, T.

    2006-10-01

    We propose an innovative approach for analysing ground-based FTIR spectra which allows us to detect variabilities of lower and middle/upper tropospheric HDO/H2O ratios. We show that the proposed method is superior to common approaches. We estimate that lower tropospheric HDO/H2O ratios can be detected with a noise to signal ratio of 15% and middle/upper tropospheric ratios with a noise to signal ratio of 50%. The method requires the inversion to be performed on a logarithmic scale and to introduce an inter-species constraint. While common methods calculate the isotope ratio posterior to an independent, optimal estimation of the HDO and H2O profile, the proposed approach is an optimal estimator for the ratio itself. We apply the innovative approach to spectra measured continuously during 15 months and present, for the first time, an annual cycle of tropospheric HDO/H2O ratio profiles as detected by ground-based measurements. Outliers in the detected middle/upper tropospheric ratios are interpreted by backward trajectories.

  15. Ground-based observations of exoplanet atmospheres

    NARCIS (Netherlands)

    Mooij, Ernst Johan Walter de

    2011-01-01

    This thesis focuses on the properties of exoplanet atmospheres. The results for ground-based near-infrared secondary eclipse observations of three different exoplanets, TrES-3b, HAT-P-1b and WASP-33b, are presented which have been obtained with ground-based telescopes as part of the GROUSE project.

  16. Making sense of grounded theory in medical education.

    Science.gov (United States)

    Kennedy, Tara J T; Lingard, Lorelei A

    2006-02-01

    Grounded theory is a research methodology designed to develop, through collection and analysis of data that is primarily (but not exclusively) qualitative, a well-integrated set of concepts that provide a theoretical explanation of a social phenomenon. This paper aims to provide an introduction to key features of grounded theory methodology within the context of medical education research. In this paper we include a discussion of the origins of grounded theory, a description of key methodological processes, a comment on pitfalls encountered commonly in the application of grounded theory research, and a summary of the strengths of grounded theory methodology with illustrations from the medical education domain. The significant strengths of grounded theory that have resulted in its enduring prominence in qualitative research include its clearly articulated analytical process and its emphasis on the generation of pragmatic theory that is grounded in the data of experience. When applied properly and thoughtfully, grounded theory can address research questions of significant relevance to the domain of medical education.

  17. Industrial Personal Computer based Display for Nuclear Safety System

    International Nuclear Information System (INIS)

    Kim, Ji Hyeon; Kim, Aram; Jo, Jung Hee; Kim, Ki Beom; Cheon, Sung Hyun; Cho, Joo Hyun; Sohn, Se Do; Baek, Seung Min

    2014-01-01

    The safety display of nuclear system has been classified as important to safety (SIL:Safety Integrity Level 3). These days the regulatory agencies are imposing more strict safety requirements for digital safety display system. To satisfy these requirements, it is necessary to develop a safety-critical (SIL 4) grade safety display system. This paper proposes industrial personal computer based safety display system with safety grade operating system and safety grade display methods. The description consists of three parts, the background, the safety requirements and the proposed safety display system design. The hardware platform is designed using commercially available off-the-shelf processor board with back plane bus. The operating system is customized for nuclear safety display application. The display unit is designed adopting two improvement features, i.e., one is to provide two separate processors for main computer and display device using serial communication, and the other is to use Digital Visual Interface between main computer and display device. In this case the main computer uses minimized graphic functions for safety display. The display design is at the conceptual phase, and there are several open areas to be concreted for a solid system. The main purpose of this paper is to describe and suggest a methodology to develop a safety-critical display system and the descriptions are focused on the safety requirement point of view

  18. Industrial Personal Computer based Display for Nuclear Safety System

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Ji Hyeon; Kim, Aram; Jo, Jung Hee; Kim, Ki Beom; Cheon, Sung Hyun; Cho, Joo Hyun; Sohn, Se Do; Baek, Seung Min [KEPCO, Youngin (Korea, Republic of)

    2014-08-15

    The safety display of nuclear system has been classified as important to safety (SIL:Safety Integrity Level 3). These days the regulatory agencies are imposing more strict safety requirements for digital safety display system. To satisfy these requirements, it is necessary to develop a safety-critical (SIL 4) grade safety display system. This paper proposes industrial personal computer based safety display system with safety grade operating system and safety grade display methods. The description consists of three parts, the background, the safety requirements and the proposed safety display system design. The hardware platform is designed using commercially available off-the-shelf processor board with back plane bus. The operating system is customized for nuclear safety display application. The display unit is designed adopting two improvement features, i.e., one is to provide two separate processors for main computer and display device using serial communication, and the other is to use Digital Visual Interface between main computer and display device. In this case the main computer uses minimized graphic functions for safety display. The display design is at the conceptual phase, and there are several open areas to be concreted for a solid system. The main purpose of this paper is to describe and suggest a methodology to develop a safety-critical display system and the descriptions are focused on the safety requirement point of view.

  19. Three Dimensional Spherical Display Systems and McIDAS: Tools for Science, Education and Outreach

    Science.gov (United States)

    Kohrs, R.; Mooney, M. E.

    2010-12-01

    The Space Science and Engineering Center (SSEC) and Cooperative Institute for Meteorological Satellite Studies (CIMSS) at the University of Wisconsin are now using a 3D spherical display system and their Man computer Data Access System (McIDAS)-X and McIDAS-V as outreach tools to demonstrate how scientists and forecasters utilize satellite imagery to monitor weather and climate. Our outreach program displays orbits and data coverage of geostationary and polar satellites and demonstrates how each is beneficial for the remote sensing of Earth. Global composites of visible, infrared and water vapor images illustrate how satellite instruments collect data from different bands of the electromagnetic spectrum to monitor global weather patterns 24 hours a day. Captivating animations on spherical display systems are proving to be much more intuitive than traditional 2D displays, enabling audiences to view satellites orbiting above real-time weather systems circulating the entire globe. Complimenting the 3D spherical display system are the UNIX-based McIDAS-X and Java-based McIDAS-V software packages. McIDAS is used to composite the real-time global satellite data and create other weather related derived products. Client and server techniques used by these software packages provide the opportunity to continually update the real-time content on our globe. The enhanced functionality of McIDAS-V extends our outreach program by allowing in-depth interactive 4-dimensional views of the imagery previously viewed on the 3D spherical display system. An important goal of our outreach program is the promotion of remote sensing research and technology at SSEC and CIMSS. The 3D spherical display system has quickly become a popular tool to convey societal benefits of these endeavors. Audiences of all ages instinctively relate to recent weather events which keeps them engaged in spherical display presentations. McIDAS facilitates further exploration of the science behind the weather

  20. Rapid visual grouping and figure-ground processing using temporally structured displays.

    Science.gov (United States)

    Cheadle, Samuel; Usher, Marius; Müller, Hermann J

    2010-08-23

    We examine the time course of visual grouping and figure-ground processing. Figure (contour) and ground (random-texture) elements were flickered with different phases (i.e., contour and background are alternated), requiring the observer to group information within a pre-specified time window. It was found this grouping has a high temporal resolution: less than 20ms for smooth contours, and less than 50ms for line conjunctions with sharp angles. Furthermore, the grouping process takes place without an explicit knowledge of the phase of the elements, and it requires a cumulative build-up of information. The results are discussed in relation to the neural mechanism for visual grouping and figure-ground segregation. Copyright 2010 Elsevier Ltd. All rights reserved.

  1. Precision Landing and Hazard Avoidance Doman

    Science.gov (United States)

    Robertson, Edward A.; Carson, John M., III

    2016-01-01

    The Precision Landing and Hazard Avoidance (PL&HA) domain addresses the development, integration, testing, and spaceflight infusion of sensing, processing, and GN&C functions critical to the success and safety of future human and robotic exploration missions. PL&HA sensors also have applications to other mission events, such as rendezvous and docking. Autonomous PL&HA builds upon the core GN&C capabilities developed to enable soft, controlled landings on the Moon, Mars, and other solar system bodies. Through the addition of a Terrain Relative Navigation (TRN) function, precision landing within tens of meters of a map-based target is possible. The addition of a 3-D terrain mapping lidar sensor improves the probability of a safe landing via autonomous, real-time Hazard Detection and Avoidance (HDA). PL&HA significantly improves the probability of mission success and enhances access to sites of scientific interest located in challenging terrain. PL&HA can also utilize external navigation aids, such as navigation satellites and surface beacons. Advanced Lidar Sensors High precision ranging, velocimetry, and 3-D terrain mapping Terrain Relative Navigation (TRN) TRN compares onboard reconnaissance data with real-time terrain imaging data to update the S/C position estimate Hazard Detection and Avoidance (HDA) Generates a high-resolution, 3-D terrain map in real-time during the approach trajectory to identify safe landing targets Inertial Navigation During Terminal Descent High precision surface relative sensors enable accurate inertial navigation during terminal descent and a tightly controlled touchdown within meters of the selected safe landing target.

  2. Remote sensing based crop type mapping and evapotranspiration estimates at the farm level in arid regions of the globe

    Science.gov (United States)

    Ozdogan, M.; Serrat-Capdevila, A.; Anderson, M. C.

    2017-12-01

    Despite increasing scarcity of freshwater resources, there is dearth of spatially explicit information on irrigation water consumption through evapotranspiration, particularly in semi-arid and arid geographies. Remote sensing, either alone or in combination with ground surveys, is increasingly being used for irrigation water management by quantifying evaporative losses at the farm level. Increased availability of observations, sophisticated algorithms, and access to cloud-based computing is also helping this effort. This presentation will focus on crop-specific evapotranspiration estimates at the farm level derived from remote sensing in a number of water-scarce regions of the world. The work is part of a larger effort to quantify irrigation water use and improve use efficiencies associated with several World Bank projects. Examples will be drawn from India, where groundwater based irrigation withdrawals are monitored with the help of crop type mapping and evapotranspiration estimates from remote sensing. Another example will be provided from a northern irrigation district in Mexico, where remote sensing is used for detailed water accounting at the farm level. These locations exemplify the success stories in irrigation water management with the help of remote sensing with the hope that spatially disaggregated information on evapotranspiration can be used as inputs for various water management decisions as well as for better water allocation strategies in many other water scarce regions.

  3. Maintain and Regain Well Clear: Maneuver Guidance Designs for Pilots Performing the Detect-and-Avoid Task

    Science.gov (United States)

    Monk, Kevin J.; Roberts, Zachary

    2017-01-01

    In order to support the future expansion and integration of Unmanned Aircraft Systems (UAS), ongoing research efforts have sought to produce findings that inform the minimum display information elements required for acceptable UAS pilot response times and traffic avoidance. Previous simulations have revealed performance benefits associated with DAA displays containing predictive information and suggestive maneuver guidance tools in the form of banding. The present study investigated the impact of various maneuver guidance display configurations on detect-and-avoid (DAA) task performance in a simulated airspace environment. UAS pilots ability to maintain DAA well clear was compared between displays with either the presence or absence of green DAA bands, which indicated conflict-free flight regions. Additional display comparisons assessed pilots ability to regain DAA well clear with two different guidance presentations designed to aid in DAA well clear recovery during critical encounters. Performance implications and display considerations for future UAS DAA systems are discussed.

  4. Cloud-to-Ground Lightning Estimates Derived from SSMI Microwave Remote Sensing and NLDN

    Science.gov (United States)

    Winesett, Thomas; Magi, Brian; Cecil, Daniel

    2015-01-01

    Lightning observations are collected using ground-based and satellite-based sensors. The National Lightning Detection Network (NLDN) in the United States uses multiple ground sensors to triangulate the electromagnetic signals created when lightning strikes the Earth's surface. Satellite-based lightning observations have been made from 1998 to present using the Lightning Imaging Sensor (LIS) on the NASA Tropical Rainfall Measuring Mission (TRMM) satellite, and from 1995 to 2000 using the Optical Transient Detector (OTD) on the Microlab-1 satellite. Both LIS and OTD are staring imagers that detect lightning as momentary changes in an optical scene. Passive microwave remote sensing (85 and 37 GHz brightness temperatures) from the TRMM Microwave Imager (TMI) has also been used to quantify characteristics of thunderstorms related to lightning. Each lightning detection system has fundamental limitations. TRMM satellite coverage is limited to the tropics and subtropics between 38 deg N and 38 deg S, so lightning at the higher latitudes of the northern and southern hemispheres is not observed. The detection efficiency of NLDN sensors exceeds 95%, but the sensors are only located in the USA. Even if data from other ground-based lightning sensors (World Wide Lightning Location Network, the European Cooperation for Lightning Detection, and Canadian Lightning Detection Network) were combined with TRMM and NLDN, there would be enormous spatial gaps in present-day coverage of lightning. In addition, a globally-complete time history of observed lightning activity is currently not available either, with network coverage and detection efficiencies varying through the years. Previous research using the TRMM LIS and Microwave Imager (TMI) showed that there is a statistically significant correlation between lightning flash rates and passive microwave brightness temperatures. The physical basis for this correlation emerges because lightning in a thunderstorm occurs where ice is first

  5. VME-based remote instrument control without ground loops

    CERN Document Server

    Belleman, J; González, J L

    1997-01-01

    New electronics has been developed for the remote control of the pick-up electrodes at the CERN Proton Synchrotron (PS). Communication between VME-based control computers and remote equipment is via full duplex point-to-point digital data links. Data are sent and received in serial format over simple twisted pairs at a rate of 1 Mbit/s, for distances of up to 300 m. Coupling transformers are used to avoid ground loops. The link hardware consists of a general-purpose VME-module, the 'TRX' (transceiver), containing four FIFO-buffered communication channels, and a dedicated control card for each remote station. Remote transceiver electronics is simple enough not to require micro-controllers or processors. Currently, some sixty pick-up stations of various types, all over the PS Complex (accelerators and associated beam transfer lines) are equipped with the new system. Even though the TRX was designed primarily for communication with pick-up electronics, it could also be used for other purposes, for example to for...

  6. pH preference and avoidance responses of adult brook trout Salvelinus fontinalis and brown trout Salmo trutta.

    Science.gov (United States)

    Fost, B A; Ferreri, C P

    2015-03-01

    The pH preferred and avoided by wild, adult brook trout Salvelinus fontinalis and brown trout Salmo trutta was examined in a series a laboratory tests using gradual and steep-gradient flow-through aquaria. The results were compared with those published for the observed segregation patterns of juvenile S. fontinalis and S. trutta in Pennsylvania streams. The adult S. trutta tested showed a preference for pH 4·0 while adult S. fontinalis did not prefer any pH within the range tested. Salmo trutta are not found in Pennsylvania streams with a base-flow pH < 5·8 which suggests that S. trutta prefer pH well above 4·0. Adult S. trutta displayed a lack of avoidance at pH below 5·0, as also reported earlier for juveniles. The avoidance pH of wild, adult S. fontinalis (between pH 5·5 and 6·0) and S. trutta (between pH 6·5 and 7·0) did not differ appreciably from earlier study results for the avoidance pH of juvenile S. fontinalis and S. trutta. A comparison of c.i. around these avoidance estimates indicates that avoidance pH is similar among adult S. fontinalis and S. trutta in this study. The limited overlap of c.i. for avoidance pH values for the two species, however, suggests that some S. trutta will display avoidance at a higher pH when S. fontinalis will not. The results of this study indicate that segregation patterns of adult S. fontinalis and S. trutta in Pennsylvania streams could be related to pH and that competition with S. trutta could be mediating the occurrence of S. fontinalis at some pH levels. © 2015 The Fisheries Society of the British Isles.

  7. Near Real-Time Ground-to-Ground Infrared Remote-Sensing Combination and Inexpensive Visible Camera Observations Applied to Tomographic Stack Emission Measurements

    Directory of Open Access Journals (Sweden)

    Philippe de Donato

    2018-04-01

    Full Text Available Evaluation of the environmental impact of gas plumes from stack emissions at the local level requires precise knowledge of the spatial development of the cloud, its evolution over time, and quantitative analysis of each gaseous component. With extensive developments, remote-sensing ground-based technologies are becoming increasingly relevant to such an application. The difficulty of determining the exact 3-D thickness of the gas plume in real time has meant that the various gas components are mainly expressed using correlation coefficients of gas occurrences and path concentration (ppm.m. This paper focuses on a synchronous and non-expensive multi-angled approach combining three high-resolution visible cameras (GoPro-Hero3 and a scanning infrared (IR gas system (SIGIS, Bruker. Measurements are performed at a NH3 emissive industrial site (NOVACARB Society, Laneuveville-devant-Nancy, France. Visible data images were processed by a first geometrical reconstruction gOcad® protocol to build a 3-D envelope of the gas plume which allows estimation of the plume’s thickness corresponding to the 2-D infrared grid measurements. NH3 concentration data could thereby be expressed in ppm and have been interpolated using a second gOcad® interpolation algorithm allowing a precise volume visualization of the NH3 distribution in the flue gas steam.

  8. Hydrogeology, simulated ground-water flow, and ground-water quality, Wright-Patterson Air Force Base, Ohio

    Science.gov (United States)

    Dumouchelle, D.H.; Schalk, C.W.; Rowe, G.L.; De Roche, J.T.

    1993-01-01

    Ground water is the primary source of water in the Wright-Patterson Air Force Base area. The aquifer consists of glacial sands and gravels that fill a buried bedrock-valley system. Consolidated rocks in the area consist of poorly permeable Ordovician shale of the Richmondian stage, in the upland areas, the Brassfield Limestone of Silurian age. The valleys are filled with glacial sediments of Wisconsinan age consisting of clay-rich tills and coarse-grained outwash deposits. Estimates of hydraulic conductivity of the shales based on results of displacement/recovery tests range from 0.0016 to 12 feet per day; estimates for the glacial sediments range from less than 1 foot per day to more than 1,000 feet per day. Ground water flow from the uplands towards the valleys and the major rivers in the region, the Great Miami and the Mad Rivers. Hydraulic-head data indicate that ground water flows between the bedrock and unconsolidated deposits. Data from a gain/loss study of the Mad River System and hydrographs from nearby wells reveal that the reach of the river next to Wright-Patterson Air Force Base is a ground-water discharge area. A steady-state, three-dimensional ground-water-flow model was developed to simulate ground-water flow in the region. The model contains three layers and encompasses about 100 square miles centered on Wright-Patterson Air Force Base. Ground water enters the modeled area primarily by river leakage and underflow at the model boundary. Ground water exits the modeled area primarily by flow through the valleys at the model boundaries and through production wells. A model sensitivity analysis involving systematic changes in values of hydrologic parameters in the model indicates that the model is most sensitive to decreases in riverbed conductance and vertical conductance between the upper two layers. The analysis also indicates that the contribution of water to the buried-valley aquifer from the bedrock that forms the valley walls is about 2 to 4

  9. Ground-based remote sensing profiling and numerical weather prediction model to manage nuclear power plants meteorological surveillance in Switzerland

    Directory of Open Access Journals (Sweden)

    B. Calpini

    2011-08-01

    Full Text Available The meteorological surveillance of the four nuclear power plants in Switzerland is of first importance in a densely populated area such as the Swiss Plateau. The project "Centrales Nucléaires et Météorologie" CN-MET aimed at providing a new security tool based on one hand on the development of a high resolution numerical weather prediction (NWP model. The latter is providing essential nowcasting information in case of a radioactive release from a nuclear power plant in Switzerland. On the other hand, the model input over the Swiss Plateau is generated by a dedicated network of surface and upper air observations including remote sensing instruments (wind profilers and temperature/humidity passive microwave radiometers. This network is built upon three main sites ideally located for measuring the inflow/outflow and central conditions of the main wind field in the planetary boundary layer over the Swiss Plateau, as well as a number of surface automatic weather stations (AWS. The network data are assimilated in real-time into the fine grid NWP model using a rapid update cycle of eight runs per day (one forecast every three hours. This high resolution NWP model has replaced the former security tool based on in situ observations (in particular one meteorological mast at each of the power plants and a local dispersion model. It is used to forecast the dynamics of the atmosphere in the planetary boundary layer (typically the first 4 km above ground layer and over a time scale of 24 h. This tool provides at any time (e.g. starting at the initial time of a nuclear power plant release the best picture of the 24-h evolution of the air mass over the Swiss Plateau and furthermore generates the input data (in the form of simulated values substituting in situ observations required for the local dispersion model used at each of the nuclear power plants locations. This paper is presenting the concept and two validation studies as well as the results of an

  10. Ground-based hyperspectral remote sensing to discriminate biotic stress in cotton crop

    Science.gov (United States)

    Nigam, Rahul; Kot, Rajsi; Sandhu, Sandeep S.; Bhattacharya, Bimal K.; Chandi, Ravinder S.; Singh, Manjeet; Singh, Jagdish; Manjunath, K. R.

    2016-05-01

    A large gap exists between the potential yield and the yield realized at the agricultural field. Among the factors contributing towards this yield gap are the biotic stresses that affect the crops growth and development. Severity of infestation of the pests and diseases differs between agroclimatic region, individual crops and seasons within a region. Information about the timing of start of infestation of these diseases and pests with their gradual progress in advance could enable plan necessary pesticide schedule for the season, region on the particular crop against the specific menace expected. This could be enabled by development of region, crop and pest-specific prediction models to forewarn these menaces. In India most (70%) of the land-holding size of farmers average 0.39 ha (some even 20 m x 20 m) and only 1% crop growers holdproblems in its proper assessment and management. Thus, such exercise could be highly time-consuming and labour-intensive for the seventh largest country with difficult terrain, 66% gross cropped area under food crops, lacking in number of skilled manpower and shrinking resources. Remote sensing overcomes such limitations with ability to access all parts of the country and can often achieve a high spatial, temporal and spectral resolution and thus leading to an accurate estimation of area affected. Due to pest and disease stress plants showed different behavior in terms of physiological and morphological changes lead to symptoms such as wilting, curling of leaf, stunned growth, reduction in leaf area due to severe defoliation or chlorosis or necrosis of photosynthetically active parts (Prabhakar et al., 2011; Booteet al., 1983; Aggarwal et al., 2006). Damage evaluation of diseases has been largely done by visual inspections and quantification but visual quantification of plant pest and diseases with accuracy and precision is a tough task. Utilization of remote sensing techniques are based on the assumption that plant pest and disease

  11. Primary display latency criteria based on flying qualities and performance data

    Science.gov (United States)

    Funk, John D., Jr.; Beck, Corin P.; Johns, John B.

    1993-01-01

    With a pilots' increasing use of visual cue augmentation, much requiring extensive pre-processing, there is a need to establish criteria for new avionics/display design. The timeliness and synchronization of the augmented cues is vital to ensure the performance quality required for precision mission task elements (MTEs) where augmented cues are the primary source of information to the pilot. Processing delays incurred while transforming sensor-supplied flight information into visual cues are unavoidable. Relationships between maximum control system delays and associated flying qualities levels are documented in MIL-F-83300 and MIL-F-8785. While cues representing aircraft status may be just as vital to the pilot as prompt control response for operations in instrument meteorological conditions, presently, there are no specification requirements on avionics system latency. To produce data relating avionics system latency to degradations in flying qualities, the Navy conducted two simulation investigations. During the investigations, flying qualities and performance data were recorded as simulated avionics system latency was varied. Correlated results of the investigation indicates that there is a detrimental impact of latency on flying qualities. Analysis of these results and consideration of key factors influencing their application indicate that: (1) Task performance degrades and pilot workload increases as latency is increased. Inconsistency in task performance increases as latency increases. (2) Latency reduces the probability of achieving Level 1 handling qualities with avionics system latency as low as 70 ms. (3) The data suggest that the achievement of desired performance will be ensured only at display latency values below 120 ms. (4) These data also suggest that avoidance of inadequate performance will be ensured only at display latency values below 150 ms.

  12. Advanced Fiber Optic-Based Sensing Technology for Unmanned Aircraft Systems

    Science.gov (United States)

    Richards, Lance; Parker, Allen R.; Piazza, Anthony; Ko, William L.; Chan, Patrick; Bakalyar, John

    2011-01-01

    This presentation provides an overview of fiber optic sensing technology development activities performed at NASA Dryden in support of Unmanned Aircraft Systems. Examples of current and previous work are presented in the following categories: algorithm development, system development, instrumentation installation, ground R&D, and flight testing. Examples of current research and development activities are provided.

  13. Combining remote sensing and water-balance evapotranspiration estimates for the conterminous United States

    Science.gov (United States)

    Reitz, Meredith; Senay, Gabriel; Sanford, Ward E.

    2017-01-01

    Evapotranspiration (ET) is a key component of the hydrologic cycle, accounting for ~70% of precipitation in the conterminous U.S. (CONUS), but it has been a challenge to predict accurately across different spatio-temporal scales. The increasing availability of remotely sensed data has led to significant advances in the frequency and spatial resolution of ET estimates, derived from energy balance principles with variables such as temperature used to estimate surface latent heat flux. Although remote sensing methods excel at depicting spatial and temporal variability, estimation of ET independently of other water budget components can lead to inconsistency with other budget terms. Methods that rely on ground-based data better constrain long-term ET, but are unable to provide the same temporal resolution. Here we combine long-term ET estimates from a water-balance approach with the SSEBop (operational Simplified Surface Energy Balance) remote sensing-based ET product for 2000–2015. We test the new combined method, the original SSEBop product, and another remote sensing ET product (MOD16) against monthly measurements from 119 flux towers. The new product showed advantages especially in non-irrigated areas where the new method showed a coefficient of determination R2 of 0.44, compared to 0.41 for SSEBop or 0.35 for MOD16. The resulting monthly data set will be a useful, unique contribution to ET estimation, due to its combination of remote sensing-based variability and ground-based long-term water balance constraints.

  14. Recurrent, robust and scalable patterns underlie human approach and avoidance.

    Directory of Open Access Journals (Sweden)

    Byoung Woo Kim

    2010-05-01

    Full Text Available Approach and avoidance behavior provide a means for assessing the rewarding or aversive value of stimuli, and can be quantified by a keypress procedure whereby subjects work to increase (approach, decrease (avoid, or do nothing about time of exposure to a rewarding/aversive stimulus. To investigate whether approach/avoidance behavior might be governed by quantitative principles that meet engineering criteria for lawfulness and that encode known features of reward/aversion function, we evaluated whether keypress responses toward pictures with potential motivational value produced any regular patterns, such as a trade-off between approach and avoidance, or recurrent lawful patterns as observed with prospect theory.Three sets of experiments employed this task with beautiful face images, a standardized set of affective photographs, and pictures of food during controlled states of hunger and satiety. An iterative modeling approach to data identified multiple law-like patterns, based on variables grounded in the individual. These patterns were consistent across stimulus types, robust to noise, describable by a simple power law, and scalable between individuals and groups. Patterns included: (i a preference trade-off counterbalancing approach and avoidance, (ii a value function linking preference intensity to uncertainty about preference, and (iii a saturation function linking preference intensity to its standard deviation, thereby setting limits to both.These law-like patterns were compatible with critical features of prospect theory, the matching law, and alliesthesia. Furthermore, they appeared consistent with both mean-variance and expected utility approaches to the assessment of risk. Ordering of responses across categories of stimuli demonstrated three properties thought to be relevant for preference-based choice, suggesting these patterns might be grouped together as a relative preference theory. Since variables in these patterns have been

  15. The relationship of work avoidance and learning goals to perceived competence, externality and meaning.

    Science.gov (United States)

    Seifert, T L; O'Keefe, B A

    2001-03-01

    Motivational researchers have suggested that work avoidance may be an academic goal in which students seek to minimise the amount of work they do in school. Additionally, research has also suggested that emotions may be catalysts for goals. This study examined the relationship between emotions and learning or work avoidance goals. Do emotions explain goals? The participants were 512 senior high school students in Eastern Canada. Students completed a survey assessing motivation related constructs. A structural equation model was postulated in which students' affect predicted learning goals and work avoidant goals. A cluster analysis of affect scores was performed followed by between-group and within-group contrasts of goal scores. The structural equation model suggested that a sense of competence and control were predictive of a learning goal while lack of meaning was related to work avoidance. The cluster analysis showed that confidence and control were associated with a learning goal but that a sense of inadequacy, lack of control or lack of meaning could give rise to work avoidance. Emotions seem to be directly linked to goals. Teachers who foster feelings of self-assuredness will be helping students develop learning goals. Students who feel less competent, bored or have little control will adopt work avoidant goals.

  16. Estimation of crown biomass of Pinus pinaster stands and shrubland above-ground biomass using forest inventory data, remotely sensed imagery and spatial prediction models

    Science.gov (United States)

    H. Viana; J. Aranha; D. Lopes; Warren B. Cohen

    2012-01-01

    Spatially crown biomass of Pinus pinaster stands and shrubland above-ground biomass (AGB) estimation was carried-out in a region located in Centre-North Portugal, by means of different approaches including forest inventory data, remotely sensed imagery and spatial prediction models. Two cover types (pine stands and shrubland) were inventoried and...

  17. Integrated modelling of the water cycle in semi arid watersheds based on ground and satellite data: the SudMed project

    Science.gov (United States)

    Simonneaux, V.; Abourida, A.; Boudhar, A.; Cheggour, A.; Chaponnière, A.; Berjamy, B.; Boulet, G.; Chehbouni, A.; Drapeau, L.; Duchemin, B.; Erraki, S.; Ezzahar, J.; Escadafal, R.; Guemouria, N.; Hanich, L.; Jarlan, L.; Kharrou, H.; Khabba, S.; Le Page, M.; Mangiarotti, S.; Merlin, O.; Mougenot, B.; Mokssit, A.; Ouldbba, A.; Chehbouni, A.

    2010-10-01

    The SudMed project aims since 2002 at modelling the hydrological cycle in the Tensift semi arid watershed located in central Morocco. To reach these modelling objectives, emphasis is put on the use of high and low resolution remote sensing data, in the visible, near infrared, thermal, and microwave domains, to initialize, to force or to control the implementation of the process models. Fundamental studies have been conducted on Soil-Vegetation-Atmosphere Transfer modelling (SVAT), especially related to the various means of incorporating both ground and remote sensing observation into them. Satellite data have been used for monitoring the snow dynamic which is a major contribution to runoff issued from the mountains. Remote sensing image time series have also been used to map the land cover, based on NDVI time profiles analysis or temporal unmixing of low resolution pixels. Subsequently, remote sensing time series proved to be very valuable for monitoring the development of vegetation and the crop water status, in order to estimate of evapotranspiration, key information for irrigation management.

  18. Adapting a Natura 2000 field guideline for a remote sensing-based assessment of heathland conservation status

    Science.gov (United States)

    Schmidt, Johannes; Fassnacht, Fabian Ewald; Neff, Christophe; Lausch, Angela; Kleinschmit, Birgit; Förster, Michael; Schmidtlein, Sebastian

    2017-08-01

    Remote sensing can be a valuable tool for supporting nature conservation monitoring systems. However, for many areas of conservation interest, there is still a considerable gap between field-based operational monitoring guidelines and the current remote sensing-based approaches. This hampers application in practice of the latter. Here, we propose a remote sensing approach for mapping the conservation status of Calluna-dominated Natura 2000 dwarf shrub habitats that is closely related to field mapping schemes. We transferred the evaluation criteria of the field guidelines to three related variables that can be captured by remote sensing: (1) coverage of the key species, (2) stand structural diversity, and (3) co-occurring species. Continuous information on these variables was obtained by regressing ground reference data from field surveys and UAV flights against airborne hyperspectral imagery. Merging the three resulting quality layers in an RGB representation allowed for illustrating the habitat quality in a continuous way. User-defined thresholds can be applied to this stack of quality layers to derive an overall assessment of habitat quality in terms of nature conservation, i.e. the conservation status. In our study, we found good accordance of the remotely sensed data with field-based information for the three variables key species, stand structural diversity and co-occurring vegetation (R2 of 0.79, 0.69, and 0.71, respectively) and it was possible to derive meaningful habitat quality maps. The conservation status could be derived with an accuracy of 65%. In interpreting these results it should be considered that the remote sensing based layers are independent estimates of habitat quality in their own right and not a mere replacement of the criteria used in the field guidelines. The approach is thought to be transferable to similar regions with minor adaptions. Our results refer to Calluna heathland which we consider a comparably easy target for remote sensing

  19. Prioritization of catchments based on soil erosion using remote sensing and GIS.

    Science.gov (United States)

    Khadse, Gajanan K; Vijay, Ritesh; Labhasetwar, Pawan K

    2015-06-01

    Water and soil are the most essential natural resources for socioeconomic development and sustenance of life. A study of soil and water dynamics at a watershed level facilitates a scientific approach towards their conservation and management. Remote sensing and Geographic Information System are tools that help to plan and manage natural resources on watershed basis. Studies were conducted for the formulation of catchment area treatment plan based on watershed prioritization with soil erosion studies using remote sensing techniques, corroborated with Geographic Information System (GIS), secondary data and ground truth information. Estimation of runoff and sediment yield is necessary in prioritization of catchment for the design of soil conservation structures and for identifying the critical erosion-prone areas of a catchment for implementation of best management plan with limited resources. The Universal Soil Loss Equation, Sediment Yield Determination and silt yield index methods are used for runoff and soil loss estimation for prioritization of the catchments. On the basis of soil erosion classes, the watersheds were grouped into very high, high, moderate and low priorities. High-priority watersheds need immediate attention for soil and water conservation, whereas low-priority watershed having good vegetative cover and low silt yield index may not need immediate attention for such treatments.

  20. ITI-signals and prelimbic cortex facilitate avoidance acquisition and reduce avoidance latencies, respectively, in male WKY rats

    Directory of Open Access Journals (Sweden)

    Kevin D Beck

    2014-11-01

    Full Text Available As a model of anxiety disorder vulnerability, male Wistar-Kyoto (WKY rats acquire lever-press avoidance behavior more readily than outbred Sprague Dawley rats, and their acquisition is enhanced by the presence of a discrete signal presented during the inter-trial intervals (ITIs, suggesting it is perceived as a safety signal. A series of experiments were conducted to determine if this is the case. Additional experiments investigated if the avoidance facilitation relies upon processing through medial prefrontal cortex (mPFC. The results suggest that the ITI-signal facilitates acquisition during the early stages of the avoidance acquisition process, when the rats are initially acquiring escape behavior and then transitioning to avoidance behavior. Post-avoidance introduction of the visual ITI-signal into other associative learning tasks failed to confirm that the visual stimulus had acquired the properties of a conditioned inhibitor. Shortening the signal from the entirety of the 3 min ITI to only the first 5 s of the 3 min ITI slowed acquisition during the first 4 sessions, suggesting the flashing light is not functioning as a feedback signal. The prelimbic (PL cortex showed greater activation during the period of training when the transition from escape responding to avoidance responding occurs. Only combined PL+infralimbic cortex lesions modestly slowed avoidance acquisition, but PL cortex lesions slowed avoidance response latencies. Thus, the flashing light ITI-signal is not likely perceived as a safety signal nor is it serving as a feedback signal. The functional role of the PL cortex appears to be to increase the drive towards responding to the threat of the warning signal. Hence, avoidance susceptibility displayed by male WKY rats may be driven, in part, both by external stimuli (ITI signal as well as by enhanced threat recognition to the warning signal via the PL cortex.

  1. Monitoring Hydraulic Fracturing Using Ground-Based Controlled Source Electromagnetics

    Science.gov (United States)

    Hickey, M. S.; Trevino, S., III; Everett, M. E.

    2017-12-01

    Hydraulic fracturing allows hydrocarbon production in low permeability formations. Imaging the distribution of fluid used to create a hydraulic fracture can aid in the characterization of fracture properties such as extent of plume penetration as well as fracture azimuth and symmetry. This could contribute to improving the efficiency of an operation, for example, in helping to determine ideal well spacing or the need to refracture a zone. A ground-based controlled-source electromagnetics (CSEM) technique is ideal for imaging the fluid due to the change in field caused by the difference in the conductive properties of the fluid when compared to the background. With advances in high signal to noise recording equipment, coupled with a high-power, broadband transmitter we can show hydraulic fracture extent and azimuth with minimal processing. A 3D finite element code is used to model the complete well casing along with the layered subsurface. This forward model is used to optimize the survey design and isolate the band of frequencies with the best response. In the field, the results of the modeling are also used to create a custom pseudorandom numeric (PRN) code to control the frequencies transmitted through a grounded dipole source. The receivers record the surface voltage across two grounded dipoles, one parallel and one perpendicular to the transmitter. The data are presented as the displays of amplitude ratios across several frequencies with the associated spatial information. In this presentation, we show multiple field results in multiple basins in the United States along with the CSEM theory used to create the survey designs.

  2. Earth and atmospheric remote sensing; Proceedings of the Meeting, Orlando, FL, Apr. 2-4, 1991

    Science.gov (United States)

    Curran, Robert J. (Editor); Smith, James A. (Editor); Watson, Ken (Editor)

    1991-01-01

    The papers presented in this volume address the technical aspects of earth and atmospheric remote sensing. Topics discussed include spaceborne and ground-based applications of laser remote sensing, advanced applications of lasers in remote sensing, laser ranging applications, data analysis and systems for biospheric processes, measurements for biospheric processes, and remote sensing for geology and geophysics. Papers are presented on a space-qualified laser transmitter for lidar applications, solid state lasers for planetary exploration, automated band selection for multispectral meteorological applications, aerospace remote sensing of natural water organics, and remote sensing of volcanic ash hazards to aircraft.

  3. Uncertainties and insufficiencies: making sense of climate adaption

    Energy Technology Data Exchange (ETDEWEB)

    Toesse, Sunniva Eikeland

    2012-11-01

    The scientist papers show, first, that climate scientists are concerned about the relevance of their research and engage in practices, even though they may, in a sense, be criticized for taking the relevance for granted. They work hard to communicate their research, even this proves uncomfortable for them personally. Secondly, these first two papers have displayed a potential challenge for climate science communication and translation: climate skeptics. The scientists' fear is that people will be confused by the climate skeptics' misleading messages about the state of climate research. A related concern may be whether the way climate scientists shape their communication efforts to avoid 'sceptic attacks', in some way inhibit translation of climate knowledge? The user papers, on the other hand, show that to potential users of climate science knowledge, the knowledge is not obviously relevant. Furthermore, there are many factors - existing institutional context, professional identities and ideas about science and climate science, and aspects of the available science information - that shape the way in which evaluate relevance. Furthermore, scientists are not particularly central in these evaluations. There is, thus, an asymmetry between the scientist's engagement with relevance and the way users evaluate the relevance of climate science knowledge. How can we make sense of this? (Author)

  4. Investigation of optimal display size for detecting ground-glass opacity on high resolution computed tomography using a new digital contrast-detail phantom

    International Nuclear Information System (INIS)

    Yamaguchi, Michihiro; Fujita, Hideki; Bessho, Yuichi; Inoue, Tatsuro; Asai, Yoshiyuki; Murase, Kenya

    2011-01-01

    The purpose of this study was to clarify the relationship between display sizes of high resolution computed tomography (HRCT) images for detecting ground-glass opacity (GGO) and observer performance using a digital contrast-detail (d-CD) phantom. A structure of the d-CD phantom was determined on the basis of the actual images of GGOs and background noises of 22 patients who were diagnosed as GGO by chest HRCT. The d-CD phantom has a 512 × 512 matrix in size and has total of 100 holes: the diameter of these holes increases stepwise from 2 to 20 pixels with 2 pixels interval in a vertical direction and the CT value varies stepwise from 2 to 200 HU in a horizontal direction. The observer performance study was carried out for three different display sizes (30 cm × 30 cm as an enlarged size, 13 cm × 13 cm as an original size, and 7 cm × 7 cm as a reduced size) using a 2-megapixels LCD monitor, and it was analyzed using Friedman and Wilcoxon statistical tests. As a result, the observer performance for the original display and the reduced display sizes was superior to that for the enlarged size (P = 0.006 and 0.037 for the original display and the reduced display sizes, respectively), whereas there was no significant difference between the original display and reduced display sizes (P = 0.77). The d-CD phantom enables a short-term evaluation of observer performance and is useful in analyzing relationship between display size and observer performance.

  5. Radiation in fog: quantification of the impact on fog liquid water based on ground-based remote sensing

    Science.gov (United States)

    Wærsted, Eivind G.; Haeffelin, Martial; Dupont, Jean-Charles; Delanoë, Julien; Dubuisson, Philippe

    2017-09-01

    Radiative cooling and heating impact the liquid water balance of fog and therefore play an important role in determining their persistence or dissipation. We demonstrate that a quantitative analysis of the radiation-driven condensation and evaporation is possible in real time using ground-based remote sensing observations (cloud radar, ceilometer, microwave radiometer). Seven continental fog events in midlatitude winter are studied, and the radiative processes are further explored through sensitivity studies. The longwave (LW) radiative cooling of the fog is able to produce 40-70 g m-2 h-1 of liquid water by condensation when the fog liquid water path exceeds 30 g m-2 and there are no clouds above the fog, which corresponds to renewing the fog water in 0.5-2 h. The variability is related to fog temperature and atmospheric humidity, with warmer fog below a drier atmosphere producing more liquid water. The appearance of a cloud layer above the fog strongly reduces the LW cooling relative to a situation with no cloud above; the effect is strongest for a low cloud, when the reduction can reach 100 %. Consequently, the appearance of clouds above will perturb the liquid water balance in the fog and may therefore induce fog dissipation. Shortwave (SW) radiative heating by absorption by fog droplets is smaller than the LW cooling, but it can contribute significantly, inducing 10-15 g m-2 h-1 of evaporation in thick fog at (winter) midday. The absorption of SW radiation by unactivated aerosols inside the fog is likely less than 30 % of the SW absorption by the water droplets, in most cases. However, the aerosols may contribute more significantly if the air mass contains a high concentration of absorbing aerosols. The absorbed radiation at the surface can reach 40-120 W m-2 during the daytime depending on the fog thickness. As in situ measurements indicate that 20-40 % of this energy is transferred to the fog as sensible heat, this surface absorption can contribute

  6. Studying Sensing-Based Systems

    DEFF Research Database (Denmark)

    Kjærgaard, Mikkel Baun

    2013-01-01

    Recent sensing-based systems involve a multitude of users, devices, and places. These types of systems challenge existing approaches for conducting valid system evaluations. Here, the author discusses such evaluation challenges and revisits existing system evaluation methodologies....

  7. STUDY OF INFLUENCE OF EFFLUENT ON GROUND WATER USING REMOTE SENSING, GIS AND MODELING TECHNIQUES

    Directory of Open Access Journals (Sweden)

    S. Pathak

    2012-07-01

    Full Text Available The area lies in arid zone of western Rajasthan having very scanty rains and very low ground water reserves. Some of the other problems that are faced by the area are disposal of industrial effluent posing threat to its sustainability of water resource. Textiles, dyeing and printing industries, various mechanical process and chemical/synthetic dyes are used and considerable wastewater discharged from these textile units contains about high amount of the dyes into the adjoining drainages. This has caused degradation of water quality in this water scarce semi-arid region of the country. Pali city is located South-West, 70 Kms from Jodhpur in western Rajasthan (India. There are four Common Effluent Treatment Plant (CETP treating wastewater to meet the pollutant level permissible to river discharge, a huge amount of effluent water of these factories directly meets the into the river Bandi – a tributary of river Luni. In order to monitor the impact of industrial effluents on the environment, identifying the extent of the degradation and evolving possible means of minimizing the impacts studies on quality of effluents, polluted river water and water of adjoining wells, the contamination migration of the pollutants from the river to ground water were studied. Remote sensing analysis has been carried out using Resourcesat −1 multispectral satellite data along with DEM derived from IRS P5 stereo pair. GIS database generated of various thematic layers viz. base layer – inventorying all waterbodies in the vicinity, transport network and village layer, drainage, geomorphology, structure, land use. Analysis of spatial distribution of the features and change detection in land use/cover carried out. GIS maps have been used to help factor in spatial location of source and hydro-geomorphological settings. DEM & elevation contour helped in delineation of watershed and identifying flow modelling boundaries. Litholog data analysis carried out for aquifer

  8. Study of Influence of Effluent on Ground Water Using Remote Sensing, GIS and Modeling Techniques

    Science.gov (United States)

    Pathak, S.; Bhadra, B. K.; Sharma, J. R.

    2012-07-01

    The area lies in arid zone of western Rajasthan having very scanty rains and very low ground water reserves. Some of the other problems that are faced by the area are disposal of industrial effluent posing threat to its sustainability of water resource. Textiles, dyeing and printing industries, various mechanical process and chemical/synthetic dyes are used and considerable wastewater discharged from these textile units contains about high amount of the dyes into the adjoining drainages. This has caused degradation of water quality in this water scarce semi-arid region of the country. Pali city is located South-West, 70 Kms from Jodhpur in western Rajasthan (India). There are four Common Effluent Treatment Plant (CETP) treating wastewater to meet the pollutant level permissible to river discharge, a huge amount of effluent water of these factories directly meets the into the river Bandi - a tributary of river Luni. In order to monitor the impact of industrial effluents on the environment, identifying the extent of the degradation and evolving possible means of minimizing the impacts studies on quality of effluents, polluted river water and water of adjoining wells, the contamination migration of the pollutants from the river to ground water were studied. Remote sensing analysis has been carried out using Resourcesat -1 multispectral satellite data along with DEM derived from IRS P5 stereo pair. GIS database generated of various thematic layers viz. base layer - inventorying all waterbodies in the vicinity, transport network and village layer, drainage, geomorphology, structure, land use. Analysis of spatial distribution of the features and change detection in land use/cover carried out. GIS maps have been used to help factor in spatial location of source and hydro-geomorphological settings. DEM & elevation contour helped in delineation of watershed and identifying flow modelling boundaries. Litholog data analysis carried out for aquifer boundaries using specialized

  9. Use of a Data-Linked Weather Information Display and Effects on Pilot Navigation Decision Making in a Piloted Simulation Study

    Science.gov (United States)

    Yuchnovicz, Daniel E.; Novacek, Paul F.; Burgess, Malcolm A.; Heck, Michael L.; Stokes, Alan F.

    2001-01-01

    This study provides recommendations to the FAA and to prospective manufacturers based on an exploration of the effects of data link weather displays upon pilot decision performance. An experiment was conducted with twenty-four current instrument rated pilots who were divided into two equal groups and presented with a challenging but realistic flight scenario involving weather containing significant embedded convective activity. All flights were flown in a full-mission simulation facility within instrument meteorological conditions. The inflight weather display depicted NexRad images, graphical METARs and textual METARs. The objective was to investigate the potential for misuse of a weather display, and incorporate recommendations for the design and use of these displays. The primary conclusion of the study found that the inflight weather display did not improve weather avoidance decision making. Some of the reasons to support this finding include: the pilot's inability to easily perceive their proximity to the storms, increased workload and difficulty in deciphering METAR textual data. The compelling nature of a graphical weather display caused many pilots to reduce their reliance on corroborating weather information from other sources. Minor changes to the weather display could improve the ability of a pilot to make better decisions on hazard avoidance.

  10. Design, Construction and Evaluation of an Interchangeable Digital System to Measure Slip and Ground Speed of Existing 2WD Tractors in Iran

    Directory of Open Access Journals (Sweden)

    M Khosravi

    2012-05-01

    Full Text Available The majority of existing tractors in Iran are not equipped with any tools to measure and display slip and ground speed. This is mainly due to the lack of national standards for measuring tools and instruments of tractors. In current research, an interchangeable system for two wheel drive tractors has been designed. Furthermore, it has been assessed after construction. To measure actual and theoretical ground speed, four rotary encoders for sensing the rotation of front and rear wheels have been utilized. Slip and ground speed were measured by means of software which has been developed in an ATmega16PU microprocessor. The measured slip and speed are digitally displayed on tractor dashboard. To evaluate the performance of the system, the measured values of ground speed and slip were compared with their calculated values obtained from conventional method. The Micro-controller has been programmed in such a way that the effect of front wheel sliding on slip is eliminated. In all evaluation conditions (in field and on asphalt, the maximum difference between system measurements for slip and speed and calculated slip and speed via conventional method was 2.4% and 0.2 km h-1, respectively. With slight alteration this system can be fitted on any kind of exiting two wheel drive tractors in the country.

  11. A high spatial resolution distributed optical fiber grating sensing system based on OFDR

    Science.gov (United States)

    Dong, Ke; Xiong, Yuchuan; Wen, Hongqiao; Tong, Xinlin; Zhang, Cui; Deng, Chengwei

    2017-10-01

    A distributed optical fiber grating sensing system with large capacity and high spatial resolution is presented. Since highdensity identical weak grating array was utilized as sensing fiber, the multiplexing number was greatly increased, meanwhile, optical frequency domain reflectometry (OFDR) technology was used to implement high resolution distributed sensing system. In order to eliminate the nonlinear effect of tunable light source, a windowed FFT algorithm based on cubic spline interpolation was applied. The feasibility of the algorithm was experimentally testified, ultimately, the spatial resolution of system can reach mm-level. The influence of the crosstalk signal in the grating array on the OFDR system was analyzed. A method that a long enough delay fiber was added before the first FBG to remove crosstalk signal was proposed. The experiment was verified using an optical fiber with 113 uniform Bragg gratings at an interval of 10cm whose reflectivity are less than 1%. It demonstrates that crosstalk signal and measurement signal can be completely separated in the distance domain after adding a long enough delay fiber. Finally, the temperature experiment of distributed grating sensing system was carried out. The results display that each raster's center wavelength in the fiber link is independent of each other and the center wavelength drift has a good linear relationship with the temperature. The sensitivity of linear fitting is equal to 11.1pm/°C.

  12. Nanocontainer-based corrosion sensing coating

    International Nuclear Information System (INIS)

    Maia, F; Tedim, J; Bastos, A C; Ferreira, M G S; Zheludkevich, M L

    2013-01-01

    The present paper reports on the development of new sensing active coating on the basis of nanocontainers containing pH-indicating agent. The coating is able to detect active corrosion processes on different metallic substrates. The corrosion detection functionality based on the local colour change in active cathodic zones results from the interaction of hydroxide ions with phenolphthalein encapsulated in mesoporous nanocontainers which function as sensing nanoreactors. The mesoporous silica nanocontainers are synthesized and loaded with pH indicator phenolphthalein in a one-stage process. The resulting system is mesoporous, which together with bulkiness of the indicator molecules limits their leaching. At the same time, penetration of water molecules and ions inside the container is still possible, allowing encapsulated phenolphthalein to be sensitive to the pH in the surrounding environment and outperforming systems when an indicator is directly dispersed in the coating layer. The performed tests demonstrate the pH sensitivity of the developed nanocontainers being dispersed in aqueous solutions. The corrosion sensing functionality of the protective coatings with nanocontainers are proven for aluminium- and magnesium-based metallic substrates. As a result, the developed nanocontainers show high potential to be used in a new generation of active protective coatings with corrosion-sensing coatings. (paper)

  13. Determination of Potential Fishing Grounds of Rastrelliger kanagurta Using Satellite Remote Sensing and GIS Technique

    International Nuclear Information System (INIS)

    Suhartono Nurdin; Muzzneena Ahmad Mustapha; Tukimat Lihan; Mazlan Abdul Ghaffar; Muzzneena Ahmad Mustapha; Nurdin, S.

    2015-01-01

    Analysis of relationship between sea surface temperature (SST) and Chlorophyll-a (chl-a) improves our understanding on the variability and productivity of the marine environment, which is important for exploring fishery resources. Monthly level 3 and daily level 1 images of Moderate Resolution Imaging Spectroradiometer Satellite (MODIS) derived SST and chl-a from July 2002 to June 2011 around the archipelagic waters of Spermonde Indonesia were used to investigate the relationship between SST and chl-a and to forecast the potential fishing ground of Rastrelliger kanagurta. The results indicated that there was positive correlation between SST and chl-a (R=0.3, p<0.05). Positive correlation was also found between SST and chl-a with the catch of R. kanagurta (R=0.7, p<0.05). The potential fishing grounds of R. kanagurta were found located along the coast (at accuracy of 76.9 %). This study indicated that, with the integration of remote sensing technology, statistical modeling and geographic information systems (GIS) technique were able to determine the relationship between SST and chl-a and also able to forecast aggregation of R. kanagurta. This may contribute in decision making and reducing search hunting time and cost in fishing activities. (author)

  14. Research of building information extraction and evaluation based on high-resolution remote-sensing imagery

    Science.gov (United States)

    Cao, Qiong; Gu, Lingjia; Ren, Ruizhi; Wang, Lang

    2016-09-01

    Building extraction currently is important in the application of high-resolution remote sensing imagery. At present, quite a few algorithms are available for detecting building information, however, most of them still have some obvious disadvantages, such as the ignorance of spectral information, the contradiction between extraction rate and extraction accuracy. The purpose of this research is to develop an effective method to detect building information for Chinese GF-1 data. Firstly, the image preprocessing technique is used to normalize the image and image enhancement is used to highlight the useful information in the image. Secondly, multi-spectral information is analyzed. Subsequently, an improved morphological building index (IMBI) based on remote sensing imagery is proposed to get the candidate building objects. Furthermore, in order to refine building objects and further remove false objects, the post-processing (e.g., the shape features, the vegetation index and the water index) is employed. To validate the effectiveness of the proposed algorithm, the omission errors (OE), commission errors (CE), the overall accuracy (OA) and Kappa are used at final. The proposed method can not only effectively use spectral information and other basic features, but also avoid extracting excessive interference details from high-resolution remote sensing images. Compared to the original MBI algorithm, the proposed method reduces the OE by 33.14% .At the same time, the Kappa increase by 16.09%. In experiments, IMBI achieved satisfactory results and outperformed other algorithms in terms of both accuracies and visual inspection

  15. Obstacle Detection Display for Visually Impaired: Coding of Direction, Distance, and Height on a Vibrotactile Waist Band

    Directory of Open Access Journals (Sweden)

    Jan B. F. van Erp

    2017-10-01

    Full Text Available Electronic travel aids (ETAs can potentially increase the safety and comfort of blind users by detecting and displaying obstacles outside the range of the white cane. In a series of experiments, we aim to balance the amount of information displayed and the comprehensibility of the information taking into account the risk of information overload. In Experiment 1, we investigate perception of compound signals displayed on a tactile vest while walking. The results confirm that the threat of information overload is clear and present. Tactile coding parameters that are sufficiently discriminable in isolation may not be so in compound signals and while walking and using the white cane. Horizontal tactor location is a strong coding parameter, and temporal pattern is the preferred secondary coding parameter. Vertical location is also possible as coding parameter but it requires additional tactors and makes the display hardware more complex and expensive and less user friendly. In Experiment 2, we investigate how we can off-load the tactile modality by mitigating part of the information to an auditory display. Off-loading the tactile modality through auditory presentation is possible, but this off-loading is limited and may result in a new threat of auditory overload. In addition, taxing the auditory channel may in turn interfere with other auditory cues from the environment. In Experiment 3, we off-load the tactile sense by reducing the amount of displayed information using several filter rules. The resulting design was evaluated in Experiment 4 with visually impaired users. Although they acknowledge the potential of the display, the added of the ETA as a whole also depends on its sensor and object recognition capabilities. We recommend to use not more than two coding parameters in a tactile compound message and apply filter rules to reduce the amount of obstacles to be displayed in an obstacle avoidance ETA.

  16. Pervasive displays understanding the future of digital signage

    CERN Document Server

    Davies, Nigel; Alt, Florian

    2014-01-01

    Fueled by falling display hardware costs and rising demand, digital signage and pervasive displays are becoming ever more ubiquitous. Such systems have traditionally been used for advertising and information dissemination, with digital signage commonplace in shopping malls, airports and public spaces. While advertising and broadcasting announcements remain important applications, developments in sensing and interaction technologies are enabling entirely new classes of display applications that tailor content to the situation and audience of the display. As a result, signage systems are beginni

  17. Incubator Display Software Cost Reduction Toolset Software Requirements Specification

    Science.gov (United States)

    Moran, Susanne; Jeffords, Ralph

    2005-01-01

    The Incubator Display Software Requirements Specification was initially developed by Intrinsyx Technologies Corporation (Intrinsyx) under subcontract to Lockheed Martin, Contract Number NAS2-02090, for the National Aeronautics and Space Administration (NASA) Ames Research Center (ARC) Space Station Biological Research Project (SSBRP). The Incubator Display is a User Payload Application (UPA) used to control an Incubator subrack payload for the SSBRP. The Incubator Display functions on-orbit as part of the subrack payload laptop, on the ground as part of the Communication and Data System (CDS) ground control system, and also as part of the crew training environment.

  18. Microprocessor based beam intensity and efficiency display system for the Fermilab accelerator

    International Nuclear Information System (INIS)

    Biwer, R.

    1979-01-01

    The Main Accelerator display system for the Fermilab accelerator gathers charge data and displays it including processed transfer efficiencies of each of the accelerators. To accomplish this, strategically located charge converters monitor the circulating internal beam of each of the Fermilab accelerators. Their outputs are processed via an asynchronously triggered, multiplexed analog-to-digital converter. The data is converted into a digital byte containing address code and data, then stores it into two 16-bit memories. One memory outputs the interleaved data as a data pulse train while the other interfaces directly to a local host computer for further analysis. The microprocessor based display unit synchronizes displayed data during normal operation as well as special storage modes. The display unit outputs data to the fron panel in the form of a numeric value and also makes digital-to-analog conversions of displayed data for external peripheral devices. 5 refs

  19. Remote Sensing Image Registration Using Multiple Image Features

    Directory of Open Access Journals (Sweden)

    Kun Yang

    2017-06-01

    Full Text Available Remote sensing image registration plays an important role in military and civilian fields, such as natural disaster damage assessment, military damage assessment and ground targets identification, etc. However, due to the ground relief variations and imaging viewpoint changes, non-rigid geometric distortion occurs between remote sensing images with different viewpoint, which further increases the difficulty of remote sensing image registration. To address the problem, we propose a multi-viewpoint remote sensing image registration method which contains the following contributions. (i A multiple features based finite mixture model is constructed for dealing with different types of image features. (ii Three features are combined and substituted into the mixture model to form a feature complementation, i.e., the Euclidean distance and shape context are used to measure the similarity of geometric structure, and the SIFT (scale-invariant feature transform distance which is endowed with the intensity information is used to measure the scale space extrema. (iii To prevent the ill-posed problem, a geometric constraint term is introduced into the L2E-based energy function for better behaving the non-rigid transformation. We evaluated the performances of the proposed method by three series of remote sensing images obtained from the unmanned aerial vehicle (UAV and Google Earth, and compared with five state-of-the-art methods where our method shows the best alignments in most cases.

  20. Remote sensing and monitor system for a large poultry farm based on Internet

    Science.gov (United States)

    Bai, Hongwu; Teng, Guanghui; Ma, Liang; Li, Zhizhong; Yuan, Zhengdong; Li, Minzan; Yang, Xiuslayerg

    2005-09-01

    A remote sensing and monitor system for a large poultry layer farm is developed based on distributed data acquisition and internet control. The supervising system applied patent techniques known as arc orbit movable vidicon, wireless video transmission and telecommunications. It features supervising at all orientations, and digital video telecommunicating through internet. All measured and control information is sent to a central computer, which is in charge of storing, displaying, analyzing and serving to internet, where managers can monitor real time production scene anywhere and customers can also see the healthy layers through internet. This paper primarily discusses how to design the remote sensing and monitor system (RSMS), and its usage in a large poultry farm, Deqingyuan Healthy Breeding Ecological Garden, Yanqing County, Beijing, China. The system applied web service technology and the middleware using XML language and Java language. It preponderated in data management, data exchange, expansibility, security, and compatibility. As a part of poultry sustainable development management system, it has been applied in a large farm with 1,200,000 layers. Tests revealed that there was distinct decline in the death ratio of chicken with 2. 2%, as the surroundings of layers had been ameliorated. At the same time, there was definite increase in the laying ratio with 3. 5%.

  1. Development of an Evaluation Method for the Design Complexity of Computer-Based Displays

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Hyoung Ju; Lee, Seung Woo; Kang, Hyun Gook; Seong, Poong Hyun [KAIST, Daejeon (Korea, Republic of); Park, Jin Kyun [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2011-10-15

    The importance of the design of human machine interfaces (HMIs) for human performance and the safety of process industries has long been continuously recognized for many decades. Especially, in the case of nuclear power plants (NPPs), HMIs have significant implications for the safety of the NPPs because poor HMIs can impair the decision making ability of human operators. In order to support and increase the decision making ability of human operators, advanced HMIs based on the up-to-date computer technology are provided. Human operators in advanced main control room (MCR) acquire information through video display units (VDUs) and large display panel (LDP), which is required for the operation of NPPs. These computer-based displays contain a huge amount of information and present it with a variety of formats compared to those of a conventional MCR. For example, these displays contain more display elements such as abbreviations, labels, icons, symbols, coding, etc. As computer-based displays contain more information, the complexity of advanced displays becomes greater due to less distinctiveness of each display element. A greater understanding is emerging about the effectiveness of designs of computer-based displays, including how distinctively display elements should be designed. This study covers the early phase in the development of an evaluation method for the design complexity of computer-based displays. To this end, a series of existing studies were reviewed to suggest an appropriate concept that is serviceable to unravel this problem

  2. Software Development for Remote Control and Firing Room Displays

    Science.gov (United States)

    Zambrano Pena, Jessica

    2014-01-01

    The Launch Control System (LCS) developed at NASA's Kennedy Space Center (KSC) will be used to launch future spacecraft. Two of the many components of this system are the Application Control Language (ACL) and remote displays. ACL is a high level domain specific language that is used to write remote control applications for LCS. Remote displays are graphical user interfaces (GUIs) developed to display vehicle and Ground Support Equipment (GSE) data, they also provide the ability to send commands to control GSE and the vehicle. The remote displays and the control applications have many facets and this internship experience dealt with several of them.

  3. Low velocity target detection based on time-frequency image for high frequency ground wave radar

    Institute of Scientific and Technical Information of China (English)

    YAN Songhua; WU Shicai; WEN Biyang

    2007-01-01

    The Doppler spectral broadening resulted from non-stationary movement of target and radio-frequency interference will decrease the veracity of target detection by high frequency ground wave(HEGW)radar.By displaying the change of signal energy on two dimensional time-frequency images based on time-frequency analysis,a new mathematical morphology method to distinguish target from nonlinear time-frequency curves is presented.The analyzed results from the measured data verify that with this new method the target can be detected correctly from wide Doppler spectrum.

  4. Avoided intersections of nodal lines

    International Nuclear Information System (INIS)

    Monastra, Alejandro G; Smilansky, Uzy; Gnutzmann, Sven

    2003-01-01

    We consider real eigenfunctions of the Schroedinger operator in 2D. The nodal lines of separable systems form a regular grid, and the number of nodal crossings equals the number of nodal domains. In contrast, for wavefunctions of non-integrable systems nodal intersections are rare, and for random waves, the expected number of intersections in any finite area vanishes. However, nodal lines display characteristic avoided crossings which we study in this work. We define a measure for the avoidance range and compute its distribution for the random wave ensemble. We show that the avoidance range distribution of wavefunctions of chaotic systems follows the expected random wave distributions, whereas for wavefunctions of classically integrable but quantum non-separable systems, the distribution is quite different. Thus, the study of the avoidance distribution provides more support to the conjecture that nodal structures of chaotic systems are reproduced by the predictions of the random wave ensemble

  5. Peer conflict avoidance: associations with loneliness, social anxiety, and social avoidance.

    Science.gov (United States)

    Johnson, H D; LaVoie, J C; Spenceri, M C; Mahoney-Wernli, M A

    2001-02-01

    Failure to resolve peer conflict is associated with children's reports of loneliness, social anxiety, and social avoidance. Although these relationships are well established, researchers have not examined the association between the avoidance of peer conflict and various adjustment characteristics. The current study examined the association between avoidance of conflict and measures of loneliness, social anxiety, and social avoidance for 59 pupils in Grade 4 (31 boys and 28 girls) and 47 in Grade 8 (22 boys and 25 girls). Volunteers indicated that conflict avoidance based on autonomy, e.g., independence issues, and interpersonal issues, e.g., closeness and cohesion, was associated with scores on loneliness for boys and girls, respectively. Conflict avoidance for emotional and physical well-being and fear of punishment was associated with increased reports of loneliness and social anxiety for children in Grade 4.

  6. Unmanned Aircraft Systems Human-in-the-Loop Controller and Pilot Acceptability Study: Collision Avoidance, Self-Separation, and Alerting Times (CASSAT)

    Science.gov (United States)

    Comstock, James R., Jr.; Ghatas, Rania W.; Vincent, Michael J.; Consiglio, Maria C.; Munoz, Cesar; Chamberlain, James P.; Volk, Paul; Arthur, Keith E.

    2016-01-01

    The Federal Aviation Administration (FAA) has been mandated by the Congressional funding bill of 2012 to open the National Airspace System (NAS) to Unmanned Aircraft Systems (UAS). With the growing use of unmanned systems, NASA has established a multi-center "UAS Integration in the NAS" Project, in collaboration with the FAA and industry, and is guiding its research efforts to look at and examine crucial safety concerns regarding the integration of UAS into the NAS. Key research efforts are addressing requirements for detect-and-avoid (DAA), self-separation (SS), and collision avoidance (CA) technologies. In one of a series of human-in-the-loop experiments, NASA Langley Research Center set up a study known as Collision Avoidance, Self-Separation, and Alerting Times (CASSAT). The first phase assessed active air traffic controller interactions with DAA systems and the second phase examined reactions to the DAA system and displays by UAS Pilots at a simulated ground control station (GCS). Analyses of the test results from Phase I and Phase II are presented in this paper. Results from the CASSAT study and previous human-in-the-loop experiments will play a crucial role in the FAA's establishment of rules, regulations, and procedures to safely, efficiently, and effectively integrate UAS into the NAS.

  7. Impact of Tactical and Strategic Weather Avoidance on Separation Assurance

    Science.gov (United States)

    Refai, Mohamad S.; Windhorst, Robert

    2011-01-01

    The ability to keep flights away from weather hazards while maintaining aircraft-to-aircraft separation is critically important. The Advanced Airspace Concept is an automation concept that implements a ground-based strategic conflict resolution algorithm for management of aircraft separation. The impact of dynamic and uncertain weather avoidance on this concept is investigated. A strategic weather rerouting system is integrated with the Advanced Airspace Concept, which also provides a tactical weather avoidance algorithm, in a fast time simulation of the Air Transportation System. Strategic weather rerouting is used to plan routes around weather in the 20 minute to two-hour time horizon. To address forecast uncertainty, flight routes are revised at 15 minute intervals. Tactical weather avoidance is used for short term trajectory adjustments (30 minute planning horizon) that are updated every minute to address any weather conflicts (instances where aircraft are predicted to pass through weather cells) that are left unresolved by strategic weather rerouting. The fast time simulation is used to assess the impact of tactical weather avoidance on the performance of automated conflict resolution as well as the impact of strategic weather rerouting on both conflict resolution and tactical weather avoidance. The results demonstrate that both tactical weather avoidance and strategic weather rerouting increase the algorithm complexity required to find aircraft conflict resolutions. Results also demonstrate that tactical weather avoidance is prone to higher airborne delay than strategic weather rerouting. Adding strategic weather rerouting to tactical weather avoidance reduces total airborne delays for the reported scenario by 18% and reduces the number of remaining weather violations by 13%. Finally, two features are identified that have proven important for strategic weather rerouting to realize these benefits; namely, the ability to revise reroutes and the use of maneuvers

  8. The Study of Cooperative Obstacle Avoidance Method for MWSN Based on Flocking Control

    Directory of Open Access Journals (Sweden)

    Zuo Chen

    2014-01-01

    Full Text Available Compared with the space fixed feature of traditional wireless sensor network (WSN, mobile WSN has better robustness and adaptability in unknown environment, so that it is always applied in the research of target tracking. In order to reach the target, the nodes group should find a self-adaptive method to avoid the obstacles together in their moving directions. Previous methods, which were based on flocking control model, realized the strategy of obstacle avoidance by means of potential field. However, these may sometimes lead the nodes group to fall into a restricted area like a trap and never get out of it. Based on traditional flocking control model, this paper introduced a new cooperative obstacle avoidance model combined with improved SA obstacle avoidance algorithm. It defined the tangent line of the intersection of node’s velocity line and the edge of obstacle as the steering direction. Furthermore, the cooperative obstacle avoidance model was also improved in avoiding complex obstacles. When nodes group encounters mobile obstacles, nodes will predict movement path based on the spatial location and velocity of obstacle. And when nodes group enters concave obstacles, nodes will temporarily ignore the gravity of the target and search path along the edge of the concave obstacles. Simulation results showed that cooperative obstacle avoidance model has significant improvement on average speed and time efficiency in avoiding obstacle compared with the traditional flocking control model. It is more suitable for obstacle avoidance in complex environment.

  9. The study of cooperative obstacle avoidance method for MWSN based on flocking control.

    Science.gov (United States)

    Chen, Zuo; Ding, Lei; Chen, Kai; Li, Renfa

    2014-01-01

    Compared with the space fixed feature of traditional wireless sensor network (WSN), mobile WSN has better robustness and adaptability in unknown environment, so that it is always applied in the research of target tracking. In order to reach the target, the nodes group should find a self-adaptive method to avoid the obstacles together in their moving directions. Previous methods, which were based on flocking control model, realized the strategy of obstacle avoidance by means of potential field. However, these may sometimes lead the nodes group to fall into a restricted area like a trap and never get out of it. Based on traditional flocking control model, this paper introduced a new cooperative obstacle avoidance model combined with improved SA obstacle avoidance algorithm. It defined the tangent line of the intersection of node's velocity line and the edge of obstacle as the steering direction. Furthermore, the cooperative obstacle avoidance model was also improved in avoiding complex obstacles. When nodes group encounters mobile obstacles, nodes will predict movement path based on the spatial location and velocity of obstacle. And when nodes group enters concave obstacles, nodes will temporarily ignore the gravity of the target and search path along the edge of the concave obstacles. Simulation results showed that cooperative obstacle avoidance model has significant improvement on average speed and time efficiency in avoiding obstacle compared with the traditional flocking control model. It is more suitable for obstacle avoidance in complex environment.

  10. UAS Integration in the NAS: Detect and Avoid

    Science.gov (United States)

    Shively, Jay

    2018-01-01

    This presentation will cover the structure of the unmanned aircraft systems (UAS) integration into the national airspace system (NAS) project (UAS-NAS Project). The talk also details the motivation of the project to help develop standards for a detect-and-avoid (DAA) system, which is required in order to comply with requirements in manned aviation to see-and-avoid other traffic so as to maintain well clear. The presentation covers accomplishments reached by the project in Phase 1 of the research, and touches on the work to be done in Phase 2. The discussion ends with examples of the display work developed as a result of the Phase 1 research.

  11. GaussStudio: designing seamless tangible interactions on portable displays

    NARCIS (Netherlands)

    Liang, R.-H.; Kuo, H.-C.; Bruns Alonso, M.; Chen, B.-Y.

    2016-01-01

    The analog Hall-sensor grid, GaussSense, is a thin-form magnetic-field camera technology for designing expressive occlusion-free, near-surface tangible interactions on conventional portable displays. The studio will provide hands-on experiences that combine physical designs and the GaussSense

  12. Ground-based measurement of column-averaged mixing ratios of methane and carbon dioxide in the Sichuan Basin of China by a desktop optical spectrum analyzer

    Science.gov (United States)

    Qin, Xiu-Chun; Nakayama, Tomoki; Matsumi, Yutaka; Kawasaki, Masahiro; Ono, Akiko; Hayashida, Sachiko; Imasu, Ryoichi; Lei, Li-Ping; Murata, Isao; Kuroki, Takahiro; Ohashi, Masafumi

    2018-01-01

    Remote sensing of the atmospheric greenhouse gases, methane (CH4) and carbon dioxide (CO2), contributes to the understanding of global warming and climate change. A portable ground-based instrument consisting of a commercially available desktop optical spectrum analyzer and a small sun tracker has been applied to measure the column densities of atmospheric CH4 and CO2 at Yanting observation station in a mountainous paddy field of the Sichuan Basin from September to November 2013. The column-averaged dry-air molar mixing ratios, XCH4/XCO2, are compared with those retrieved by satellite observations in the Sichuan Basin and by ground-based network observations in the same latitude zone as the Yanting observation station.

  13. Application of the Decomposition Method to the Design Complexity of Computer-based Display

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Hyoung Ju; Lee, Seung Woo; Seong, Poong Hyun [Korea Advanced Institute of Science and Technology, Daejeon (Korea, Republic of); Park, Jin Kyun [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2012-05-15

    The importance of the design of human machine interfaces (HMIs) for human performance and safety has long been recognized in process industries. In case of nuclear power plants (NPPs), HMIs have significant implications for the safety of the NPPs since poor implementation of HMIs can impair the operators' information searching ability which is considered as one of the important aspects of human behavior. To support and increase the efficiency of the operators' information searching behavior, advanced HMIs based on computer technology are provided. Operators in advanced main control room (MCR) acquire information through video display units (VDUs), and large display panel (LDP) required for the operation of NPPs. These computer-based displays contain a very large quantity of information and present them in a variety of formats than conventional MCR. For example, these displays contain more elements such as abbreviations, labels, icons, symbols, coding, and highlighting than conventional ones. As computer-based displays contain more information, complexity of the elements becomes greater due to less distinctiveness of each element. A greater understanding is emerging about the effectiveness of designs of computer-based displays, including how distinctively display elements should be designed. And according to Gestalt theory, people tend to group similar elements based on attributes such as shape, color or pattern based on the principle of similarity. Therefore, it is necessary to consider not only human operator's perception but the number of element consisting of computer-based display

  14. Application of the Decomposition Method to the Design Complexity of Computer-based Display

    International Nuclear Information System (INIS)

    Kim, Hyoung Ju; Lee, Seung Woo; Seong, Poong Hyun; Park, Jin Kyun

    2012-01-01

    The importance of the design of human machine interfaces (HMIs) for human performance and safety has long been recognized in process industries. In case of nuclear power plants (NPPs), HMIs have significant implications for the safety of the NPPs since poor implementation of HMIs can impair the operators' information searching ability which is considered as one of the important aspects of human behavior. To support and increase the efficiency of the operators' information searching behavior, advanced HMIs based on computer technology are provided. Operators in advanced main control room (MCR) acquire information through video display units (VDUs), and large display panel (LDP) required for the operation of NPPs. These computer-based displays contain a very large quantity of information and present them in a variety of formats than conventional MCR. For example, these displays contain more elements such as abbreviations, labels, icons, symbols, coding, and highlighting than conventional ones. As computer-based displays contain more information, complexity of the elements becomes greater due to less distinctiveness of each element. A greater understanding is emerging about the effectiveness of designs of computer-based displays, including how distinctively display elements should be designed. And according to Gestalt theory, people tend to group similar elements based on attributes such as shape, color or pattern based on the principle of similarity. Therefore, it is necessary to consider not only human operator's perception but the number of element consisting of computer-based display

  15. A study of the Oklahoma City urban heat island using ground measurements and remote sensing

    Energy Technology Data Exchange (ETDEWEB)

    Brown, M. J. (Michael J.); Ivey, A. (Austin); McPherson, T. N. (Timothy N.); Boswell, D. (David); Pardyjak, E. R. (Eric R.)

    2004-01-01

    Measurements of temperature and position were collected during the night from an instrumented van on routes through Oklahoma City and the rural outskirts. The measurements were taken as part of the Joint URBAN 2003 Tracer Field Experiment conducted in Oklahoma City from June 29, 2003 to July 30, 2003 (Allwine et al., 2004). The instrumented van was driven over four primary routes that included legs from the downtown core to four different 'rural' areas. Each route went through residential areas and most often went by a line of permanently fixed temperature probes (Allwine et al., 2004) for cross-checking purposes. Each route took from 20 to 40 minutes to complete. Based on seven nights of data, initial analyses indicate that there was a temperature difference of 0.5-6.5 C between the urban core and nearby 'rural' areas. Analyses also suggest that there were significant fine scale temperature differences over distances of tens of meters within the city and in the nearby rural areas. The temperature measurements that were collected are intended to supplement the meteorological measurements taken during the Joint URBAN 2003 Field Experiment, to assess the importance of the urban heat island phenomenon in Oklahoma City, and to test new urban canopy parameterizations that have been developed for regional scale meteorological codes (e.g., Chin et al., 2000; Holt and Shi, 2004). In addition to the ground measurements, skin temperature measurements were also analyzed from remotely sensed images taken from the Earth Observing System's Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER). A surface kinetic temperature thermal infrared image captured by the ASTER of the Oklahoma City area on July 21, 2001 was analyzed within ESRI's ArcGIS 8.3 to correlate variations in temperature with land use type. Analysis of this imagery suggests distinct variations in temperature across different land use categories. Through the use of

  16. Crowdsourcing Rapid Assessment of Collapsed Buildings Early after the Earthquake Based on Aerial Remote Sensing Image: A Case Study of Yushu Earthquake

    Directory of Open Access Journals (Sweden)

    Shuai Xie

    2016-09-01

    Full Text Available Remote sensing (RS images play a significant role in disaster emergency response. Web2.0 changes the way data are created, making it possible for the public to participate in scientific issues. In this paper, an experiment is designed to evaluate the reliability of crowdsourcing buildings collapse assessment in the early time after an earthquake based on aerial remote sensing image. The procedure of RS data pre-processing and crowdsourcing data collection is presented. A probabilistic model including maximum likelihood estimation (MLE, Bayes’ theorem and expectation-maximization (EM algorithm are applied to quantitatively estimate the individual error-rate andground truth” according to multiple participants’ assessment results. An experimental area of Yushu earthquake is provided to present the results contributed by participants. Following the results, some discussion is provided regarding accuracy and variation among participants. The features of buildings labeled as the same damage type are found highly consistent. This suggests that the building damage assessment contributed by crowdsourcing can be treated as reliable samples. This study shows potential for a rapid building collapse assessment through crowdsourcing and quantitatively inferring “ground truth” according to crowdsourcing data in the early time after the earthquake based on aerial remote sensing image.

  17. Dynamical-Decoupling-Based Quantum Sensing: Floquet Spectroscopy

    Directory of Open Access Journals (Sweden)

    J. E. Lang

    2015-10-01

    Full Text Available Sensing the internal dynamics of individual nuclear spins or clusters of nuclear spins has recently become possible by observing the coherence decay of a nearby electronic spin: the weak magnetic noise is amplified by a periodic, multipulse decoupling sequence. However, it remains challenging to robustly infer underlying atomic-scale structure from decoherence traces in all but the simplest cases. We introduce Floquet spectroscopy as a versatile paradigm for analysis of these experiments and argue that it offers a number of general advantages. In particular, this technique generalizes to more complex situations, offering physical insight in regimes of many-body dynamics, strong coupling, and pulses of finite duration. As there is no requirement for resonant driving, the proposed spectroscopic approach permits physical interpretation of striking, but overlooked, coherence decay features in terms of the form of the avoided crossings of the underlying quasienergy eigenspectrum. This is exemplified by a set of “diamond-shaped” features arising for transverse-field scans in the case of single-spin sensing by nitrogen-vacancy centers in diamond. We also investigate applications for donors in silicon, showing that the resulting tunable interaction strengths offer highly promising future sensors.

  18. Solid-state emissive triarylborane-based BODIPY dyes: photophysical properties and fluorescent sensing for fluoride and cyanide ions.

    Science.gov (United States)

    Fu, Guang-Liang; Pan, Hong; Zhao, Yi-Hong; Zhao, Cui-Hua

    2011-12-07

    We disclose two novel BODIPY dyes, which contain the bulky substituent, [(4-dimesitylboryl)phenyl]ethynyl at 2- and 2,6-positions. The steric bulkiness of the boryl group is effective to suppress the intermolecular interaction in the solid state and thus these two compounds display intense fluorescence not only in solution but also in the solid state. In addition, the BODIPY dyes display sensitive fluorescence responses to fluoride and cyanide anions through the complexation with the boron center of the boryl group and the subsequent decomposition of the BODIPY core, illustrating their potential uses for the fluorescence sensing of fluoride and cyanide ions.

  19. Preliminary study on magnetic tracking-based planar shape sensing and navigation for flexible surgical robots in transoral surgery: methods and phantom experiments.

    Science.gov (United States)

    Song, Shuang; Zhang, Changchun; Liu, Li; Meng, Max Q-H

    2018-02-01

    Flexible surgical robot can work in confined and complex environments, which makes it a good option for minimally invasive surgery. In order to utilize flexible manipulators in complicated and constrained surgical environments, it is of great significance to monitor the position and shape of the curvilinear manipulator in real time during the procedures. In this paper, we propose a magnetic tracking-based planar shape sensing and navigation system for flexible surgical robots in the transoral surgery. The system can provide the real-time tip position and shape information of the robot during the operation. We use wire-driven flexible robot to serve as the manipulator. It has three degrees of freedom. A permanent magnet is mounted at the distal end of the robot. Its magnetic field can be sensed with a magnetic sensor array. Therefore, position and orientation of the tip can be estimated utilizing a tracking method. A shape sensing algorithm is then carried out to estimate the real-time shape based on the tip pose. With the tip pose and shape display in the 3D reconstructed CT model, navigation can be achieved. Using the proposed system, we carried out planar navigation experiments on a skull phantom to touch three different target positions under the navigation of the skull display interface. During the experiments, the real-time shape has been well monitored and distance errors between the robot tip and the targets in the skull have been recorded. The mean navigation error is [Formula: see text] mm, while the maximum error is 3.2 mm. The proposed method provides the advantages that no sensors are needed to mount on the robot and no line-of-sight problem. Experimental results verified the feasibility of the proposed method.

  20. Recurrent, Robust and Scalable Patterns Underlie Human Approach and Avoidance

    Science.gov (United States)

    Kennedy, David N.; Lehár, Joseph; Lee, Myung Joo; Blood, Anne J.; Lee, Sang; Perlis, Roy H.; Smoller, Jordan W.; Morris, Robert; Fava, Maurizio

    2010-01-01

    Background Approach and avoidance behavior provide a means for assessing the rewarding or aversive value of stimuli, and can be quantified by a keypress procedure whereby subjects work to increase (approach), decrease (avoid), or do nothing about time of exposure to a rewarding/aversive stimulus. To investigate whether approach/avoidance behavior might be governed by quantitative principles that meet engineering criteria for lawfulness and that encode known features of reward/aversion function, we evaluated whether keypress responses toward pictures with potential motivational value produced any regular patterns, such as a trade-off between approach and avoidance, or recurrent lawful patterns as observed with prospect theory. Methodology/Principal Findings Three sets of experiments employed this task with beautiful face images, a standardized set of affective photographs, and pictures of food during controlled states of hunger and satiety. An iterative modeling approach to data identified multiple law-like patterns, based on variables grounded in the individual. These patterns were consistent across stimulus types, robust to noise, describable by a simple power law, and scalable between individuals and groups. Patterns included: (i) a preference trade-off counterbalancing approach and avoidance, (ii) a value function linking preference intensity to uncertainty about preference, and (iii) a saturation function linking preference intensity to its standard deviation, thereby setting limits to both. Conclusions/Significance These law-like patterns were compatible with critical features of prospect theory, the matching law, and alliesthesia. Furthermore, they appeared consistent with both mean-variance and expected utility approaches to the assessment of risk. Ordering of responses across categories of stimuli demonstrated three properties thought to be relevant for preference-based choice, suggesting these patterns might be grouped together as a relative preference

  1. Non-Intrusive, Distributed Gas Sensing Technology for Advanced Spacesuits, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — Advances in spacesuits are required to support the ISS and future human exploration. Spacesuit development and ground-based testing tasks require sensing and...

  2. ANALYSIS OF COMBINED UAV-BASED RGB AND THERMAL REMOTE SENSING DATA: A NEW APPROACH TO CROWD MONITORING

    Directory of Open Access Journals (Sweden)

    S. Schulte

    2017-08-01

    Full Text Available Collecting vast amount of data does not solely help to fulfil information needs related to crowd monitoring, it is rather important to collect data that is suitable to meet specific information requirements. In order to address this issue, a prototype is developed to facilitate the combination of UAV-based RGB and thermal remote sensing datasets. In an experimental approach, image sensors were mounted on a remotely piloted aircraft and captured two video datasets over a crowd. A group of volunteers performed diverse movements that depict real world scenarios. The prototype is deriving the movement on the ground and is programmed in MATLAB. This novel detection approach using combined data is afterwards evaluated against detection algorithms that only use a single data source. Our tests show that the combination of RGB and thermal remote sensing data is beneficial for the field of crowd monitoring regarding the detection of crowd movement.

  3. Remote sensing and water resources

    CERN Document Server

    Champollion, N; Benveniste, J; Chen, J

    2016-01-01

    This book is a collection of overview articles showing how space-based observations, combined with hydrological modeling, have considerably improved our knowledge of the continental water cycle and its sensitivity to climate change. Two main issues are highlighted: (1) the use in combination of space observations for monitoring water storage changes in river basins worldwide, and (2) the use of space data in hydrological modeling either through data assimilation or as external constraints. The water resources aspect is also addressed, as well as the impacts of direct anthropogenic forcing on land hydrology (e.g. ground water depletion, dam building on rivers, crop irrigation, changes in land use and agricultural practices, etc.). Remote sensing observations offer important new information on this important topic as well, which is highly useful for achieving water management objectives. Over the past 15 years, remote sensing techniques have increasingly demonstrated their capability to monitor components of th...

  4. The Relationship between Personality, Sense of Efficacy, and Stress in Korean Teachers

    Science.gov (United States)

    Park, Subin; Song, Yul-Mai; Ko, Guy-Nueo; Jhung, Kyungun; Ha, Kyooseob; Lee, Young-Ryeol

    2016-01-01

    Several studies have linked teachers' personality characteristics and sense of efficacy to stress. However, investigating the relationship between these three constructs in this context was limited. This study aims to investigate the relationship between personality, sense of efficacy and perceived stress among Korean teachers. A total of 137 teachers working in elementary, middle, and high schools located in Seoul, South Korea were recruited for the study. The participants were administered Temperament and Character Inventory, Teacher's Sense of Efficacy Scale (TSES), and Perceived Stress Scale. The TSES was negatively correlated with harm avoidance and positively correlated with persistence, self-directedness, cooperativeness, and self-transcendence. Perceived stress was positively correlated with harm avoidance and negatively correlated with persistence and self-directedness. The path analysis showed that harm avoidance directly predicted perceived stress (β=0.37, 95% CI=0.21–0.53, p=0.002), and self-directedness and persistence predicted one's sense of efficacy (β=0.18, 95% CI=0.01–0.39 and β=0.31, 95% CI=0.10–0.47), which predicted perceived stress (β=-0.21, 95% CI=-0.39 to -0.02). The results of the present study indicate that harm avoidance might be associated with stress-proneness, while persistence, self-directedness, and sense of efficacy might act as protective resources against stress in Korean teachers. PMID:27757136

  5. The Relationship between Personality, Sense of Efficacy, and Stress in Korean Teachers.

    Science.gov (United States)

    Park, Subin; Song, Yul-Mai; Ko, Guy-Nueo; Jhung, Kyungun; Ha, Kyooseob; Lee, Young-Ryeol; Kim, Yeni

    2016-09-01

    Several studies have linked teachers' personality characteristics and sense of efficacy to stress. However, investigating the relationship between these three constructs in this context was limited. This study aims to investigate the relationship between personality, sense of efficacy and perceived stress among Korean teachers. A total of 137 teachers working in elementary, middle, and high schools located in Seoul, South Korea were recruited for the study. The participants were administered Temperament and Character Inventory, Teacher's Sense of Efficacy Scale (TSES), and Perceived Stress Scale. The TSES was negatively correlated with harm avoidance and positively correlated with persistence, self-directedness, cooperativeness, and self-transcendence. Perceived stress was positively correlated with harm avoidance and negatively correlated with persistence and self-directedness. The path analysis showed that harm avoidance directly predicted perceived stress (β=0.37, 95% CI=0.21-0.53, p=0.002), and self-directedness and persistence predicted one's sense of efficacy (β=0.18, 95% CI=0.01-0.39 and β=0.31, 95% CI=0.10-0.47), which predicted perceived stress (β=-0.21, 95% CI=-0.39 to -0.02). The results of the present study indicate that harm avoidance might be associated with stress-proneness, while persistence, self-directedness, and sense of efficacy might act as protective resources against stress in Korean teachers.

  6. Three-dimensional simulation and auto-stereoscopic 3D display of the battlefield environment based on the particle system algorithm

    Science.gov (United States)

    Ning, Jiwei; Sang, Xinzhu; Xing, Shujun; Cui, Huilong; Yan, Binbin; Yu, Chongxiu; Dou, Wenhua; Xiao, Liquan

    2016-10-01

    The army's combat training is very important now, and the simulation of the real battlefield environment is of great significance. Two-dimensional information has been unable to meet the demand at present. With the development of virtual reality technology, three-dimensional (3D) simulation of the battlefield environment is possible. In the simulation of 3D battlefield environment, in addition to the terrain, combat personnel and the combat tool ,the simulation of explosions, fire, smoke and other effects is also very important, since these effects can enhance senses of realism and immersion of the 3D scene. However, these special effects are irregular objects, which make it difficult to simulate with the general geometry. Therefore, the simulation of irregular objects is always a hot and difficult research topic in computer graphics. Here, the particle system algorithm is used for simulating irregular objects. We design the simulation of the explosion, fire, smoke based on the particle system and applied it to the battlefield 3D scene. Besides, the battlefield 3D scene simulation with the glasses-free 3D display is carried out with an algorithm based on GPU 4K super-multiview 3D video real-time transformation method. At the same time, with the human-computer interaction function, we ultimately realized glasses-free 3D display of the simulated more realistic and immersed 3D battlefield environment.

  7. Remote sensing, hydrological modeling and in situ observations in snow cover research: A review

    Science.gov (United States)

    Dong, Chunyu

    2018-06-01

    Snow is an important component of the hydrological cycle. As a major part of the cryosphere, snow cover also represents a valuable terrestrial water resource. In the context of climate change, the dynamics of snow cover play a crucial role in rebalancing the global energy and water budgets. Remote sensing, hydrological modeling and in situ observations are three techniques frequently utilized for snow cover investigations. However, the uncertainties caused by systematic errors, scale gaps, and complicated snow physics, among other factors, limit the usability of these three approaches in snow studies. In this paper, an overview of the advantages, limitations and recent progress of the three methods is presented, and more effective ways to estimate snow cover properties are evaluated. The possibility of improving remotely sensed snow information using ground-based observations is discussed. As a rapidly growing source of volunteered geographic information (VGI), web-based geotagged photos have great potential to provide ground truth data for remotely sensed products and hydrological models and thus contribute to procedures for cloud removal, correction, validation, forcing and assimilation. Finally, this review proposes a synergistic framework for the future of snow cover research. This framework highlights the cross-scale integration of in situ and remotely sensed snow measurements and the assimilation of improved remote sensing data into hydrological models.

  8. Field tests on total gap of modular expansion joints to avoid bridge pounding

    Directory of Open Access Journals (Sweden)

    Bo eLi

    2016-03-01

    Full Text Available Modular expansion joints (MEJs are used for accommodating large relative displacements of adjacent bridge segments and for completely eliminating pounding. However, the minimum total gap that an MEJ needs to avoid pounding is not well investigated. To provide guidance for the seismic gap of MEJs, the maximum relative displacement of adjacent bridge segments subject to strong earthquakes was studied experimentally. To date, no experimental investigation of excitation spatial variation effect on bridge on natural soil has been reported. This research addressed a bridge with three identical segments of 100 m. A 1:22 scale bridge model founded on compacted beach sand was tested using electro-magnetic inertial exciters. Different ground motions were applied to the model to simulate the effect of spatially varying ground motions. Soil-structure interaction (SSI was studied by comparing the minimum total gaps with those obtained from the fixed-based experiments in the laboratory. The spatially varying ground motions were simulated based on the New Zealand design spectra for soft soil, shallow soil and strong rock conditions using an empirical coherency loss function. SSI was found to reduce the minimum total gap of an MEJ needed to avoid pounding between adjacent segments. Under spatially varying ground motions designing adjacent bridge segments with identical or similar fundamental frequencies is still recommended even if it does not necessarily preclude an out-of-phase movement of adjacent structures.

  9. Illumination compensation in ground based hyperspectral imaging

    Science.gov (United States)

    Wendel, Alexander; Underwood, James

    2017-07-01

    Hyperspectral imaging has emerged as an important tool for analysing vegetation data in agricultural applications. Recently, low altitude and ground based hyperspectral imaging solutions have come to the fore, providing very high resolution data for mapping and studying large areas of crops in detail. However, these platforms introduce a unique set of challenges that need to be overcome to ensure consistent, accurate and timely acquisition of data. One particular problem is dealing with changes in environmental illumination while operating with natural light under cloud cover, which can have considerable effects on spectral shape. In the past this has been commonly achieved by imaging known reference targets at the time of data acquisition, direct measurement of irradiance, or atmospheric modelling. While capturing a reference panel continuously or very frequently allows accurate compensation for illumination changes, this is often not practical with ground based platforms, and impossible in aerial applications. This paper examines the use of an autonomous unmanned ground vehicle (UGV) to gather high resolution hyperspectral imaging data of crops under natural illumination. A process of illumination compensation is performed to extract the inherent reflectance properties of the crops, despite variable illumination. This work adapts a previously developed subspace model approach to reflectance and illumination recovery. Though tested on a ground vehicle in this paper, it is applicable to low altitude unmanned aerial hyperspectral imagery also. The method uses occasional observations of reference panel training data from within the same or other datasets, which enables a practical field protocol that minimises in-field manual labour. This paper tests the new approach, comparing it against traditional methods. Several illumination compensation protocols for high volume ground based data collection are presented based on the results. The findings in this paper are

  10. Assessing Spatiotemporal Variability in NO2 and O3 Along the Korean Peninsula Using Remote Sensing and Ground-Based Observations

    Science.gov (United States)

    Li, C. Y. R.; Parker, O.; Tzortziou, M.

    2017-12-01

    Our research sought to use ground-based and satellite products to study the spatiotemporal variability of NO2 and O­3 in urban and coastal South Korea. Our data set was derived from direct-sun irradiance measurements of TCNO2 and TCO3 using Pandora spectrometers located at 8 ground sites and 1 boat-mounted sensor, as well as satellite observations from the Ozone Monitoring Instrument (OMI) on the Aura satellite. Our analysis focuses on the dates of the KORUSA campaign, which took place between May 18, 2016 through June 2, 2016, and provided our off-shore measurements. The Pandora instrument offered us continuous coverage of the local area, providing a detailed understanding of NO2 and O3 temporal variability. Ground stations allowed us to compare small-scale diurnal variability in urban and near-urban environments, while the Pandora mounted on the Onnuri research vessel permitted us to gain valuable insight into off-shore behavior of trace gases. By overlaying and comparing these measurements with TCO3/TCNO2 products from the Aura-OMI sensor, we were able to form a relatively complete picture of trace gas behavior above, and off-shore from, the Korean Peninsula. Our data was then subjected to statistical and GIS (Geographic Information System) analysis, quantifying and mapping (respectively) the spatial and temporal variability of total column amounts of NO2 and O3 along the Korean Peninsula. Results are shown for the eight sites where different Pandora instruments were used. There was a notable difference in TCNO2 variability which correlates with population and land use.

  11. Theoretical study of chromophores for biological sensing: Understanding the mechanism of rhodol based multi-chromophoric systems

    Science.gov (United States)

    Rivera-Jacquez, Hector J.; Masunov, Artëm E.

    2018-06-01

    Development of two-photon fluorescent probes can aid in visualizing the cellular environment. Multi-chromophore systems display complex manifolds of electronic transitions, enabling their use for optical sensing applications. Time-Dependent Density Functional Theory (TDDFT) methods allow for accurate predictions of the optical properties. These properties are related to the electronic transitions in the molecules, which include two-photon absorption cross-sections. Here we use TDDFT to understand the mechanism of aza-crown based fluorescent probes for metals sensing applications. Our findings suggest changes in local excitation in the rhodol chromophore between unbound form and when bound to the metal analyte. These changes are caused by a charge transfer from the aza-crown group and pyrazol units toward the rhodol unit. Understanding this mechanism leads to an optimized design with higher two-photon excited fluorescence to be used in medical applications.

  12. Elaborate analysis and design of filter-bank-based sensing for wideband cognitive radios

    Science.gov (United States)

    Maliatsos, Konstantinos; Adamis, Athanasios; Kanatas, Athanasios G.

    2014-12-01

    The successful operation of a cognitive radio system strongly depends on its ability to sense the radio environment. With the use of spectrum sensing algorithms, the cognitive radio is required to detect co-existing licensed primary transmissions and to protect them from interference. This paper focuses on filter-bank-based sensing and provides a solid theoretical background for the design of these detectors. Optimum detectors based on the Neyman-Pearson theorem are developed for uniform discrete Fourier transform (DFT) and modified DFT filter banks with root-Nyquist filters. The proposed sensing framework does not require frequency alignment between the filter bank of the sensor and the primary signal. Each wideband primary channel is spanned and monitored by several sensor subchannels that analyse it in narrowband signals. Filter-bank-based sensing is proved to be robust and efficient under coloured noise. Moreover, the performance of the weighted energy detector as a sensing technique is evaluated. Finally, based on the Locally Most Powerful and the Generalized Likelihood Ratio test, real-world sensing algorithms that do not require a priori knowledge are proposed and tested.

  13. Consideration of the restoring plan in subsidence prone areas through the development of ground stability assessment techniques

    Energy Technology Data Exchange (ETDEWEB)

    Kwon, Kwang-Soo; Kim, Im-Ho; Baek, Sang-Ho [Korea Institute of Geology Mining and Materials, Taejon (KR)] (and others)

    1999-12-01

    This report consists of 2 subjects. (1) Consideration of the restoring plan in subsidence prone areas through the development of ground stability assessment techniques : The number of mines at rest as well as closed have abruptly increased since the 1980's, which has caused subsidence problems around the mined areas. To protect such places from damage due to subsidence, it is necessary to develop the assessment techniques of ground stability and make restoration plan. To achieve this goal, the site investigation should have been conducted before the subsidence events occurred, but ground behaviors around the places where a vertical movement is expected and recognised in advance before the occurrence of the subsidence events. In this study ground stability analysis for the area surrounding the Moo-Geuk Mine, located close to a city, was conducted and the measurements were recorded. The objectives of the present study include, the development of a risk assessment technique for the subsidence using GIS tool, an evaluation of the numerical methods related to the site investigation and the ground stability analysis, the application of the numerical tools to the present problems. (2) Integration of coal mine data and use of remote sensing in investigation of coal mine area : This study attempt to integrate the previous geological and mining data to avoid confusions often occurred when accessing source data. And the investigation of underground mining place using remote sensing method is the other effort to assure the geographic locations of mining places as well as to find out unknown mining place. The sample region for examining the remote sensing method is the Chungnam coal field, which locates in the middle western part of South Korea. Detailed investigation was held on the Seongju area, locating north eastern part of the coal field. (author). 54 refs., tabs., figs.

  14. A stereo remote sensing feature selection method based on artificial bee colony algorithm

    Science.gov (United States)

    Yan, Yiming; Liu, Pigang; Zhang, Ye; Su, Nan; Tian, Shu; Gao, Fengjiao; Shen, Yi

    2014-05-01

    To improve the efficiency of stereo information for remote sensing classification, a stereo remote sensing feature selection method is proposed in this paper presents, which is based on artificial bee colony algorithm. Remote sensing stereo information could be described by digital surface model (DSM) and optical image, which contain information of the three-dimensional structure and optical characteristics, respectively. Firstly, three-dimensional structure characteristic could be analyzed by 3D-Zernike descriptors (3DZD). However, different parameters of 3DZD could descript different complexity of three-dimensional structure, and it needs to be better optimized selected for various objects on the ground. Secondly, features for representing optical characteristic also need to be optimized. If not properly handled, when a stereo feature vector composed of 3DZD and image features, that would be a lot of redundant information, and the redundant information may not improve the classification accuracy, even cause adverse effects. To reduce information redundancy while maintaining or improving the classification accuracy, an optimized frame for this stereo feature selection problem is created, and artificial bee colony algorithm is introduced for solving this optimization problem. Experimental results show that the proposed method can effectively improve the computational efficiency, improve the classification accuracy.

  15. Fiber sensing based on new structures and post-processing enhancement

    Science.gov (United States)

    Ferreira, Marta Sofia dos Anjos

    etching. In this case, an excimer laser was used. Extremely thin fiber tips were obtained, with an ultra-high sensitivity to strain. The other technique employed to fabricate the fiber Bragg gratings was the point-by-point femtosecond laser inscription. In this case, the sensing elements are very stable at high temperatures and can be used to measure strain in harsh conditions. The employment of optical fiber lasers as sensing elements was also considered in this Thesis. Two laser cavities were studied, one based on the ring configuration and the other based on a figure-of-eight configuration. From these works, the quality of the laser emission, namely the signal-to-noise ratio, the reduced full-width at half maximum and the stability should be highlighted. These characteristics allowed the measurement of different physical parameters, such as strain, temperature and torsion. Lastly, the possibility to use microspheres as sensing elements was considered. Using the electric arc of a fusion splicer, it is possible to create microspheres at the tip of an optical fiber. Furthermore, with this technique it is chains of microspheres can be obtained, constituting Mach-Zehnder-type interferometers which are sensitive to physical parameters like strain and temperature. The preliminary results obtained by introducing silica microspheres in a support structure are also presented. In this case, the sensors were subjected to temperature variations. All the experimental work was combined with the respective theoretical considerations. Many questions have been raised with the course of this PhD, and there are still some without a definite answer. Thus, new research paths can be followed, having their basis grounded in the configurations here presented.

  16. Cockpit Displays to Support Hazard Awareness in Free Flight

    Science.gov (United States)

    Wickens, Christopher D.; Carbonari, Ron; Merwin, Dave; Morphew, Ephimia; OBrien, Janelle V.

    1997-01-01

    Three experiments are described which each examine different aspects of the formatting and integration of cockpit displays of traffic information to support pilots in traffic avoidance planning. The first two experiments compared two-dimensional (coplanar) with three-dimensional (perspective) versions of a cockpit display of traffic information. In Experiment 1, 30 certified flight instructors flew a series of traffic conflict detection and avoidance maneuvers around an intruder aircraft, sometimes in the presence of a second intruder. The results revealed an advantage for the coplanar display, particularly when there was vertical intruder behavior. In Experiment 2, 17 instructors flew with the coplanar and perspective formats when weather information was either overlaid or displayed separately. Again performance was best with the coplanar display, particularly when the weather data were overlaid. The results of both experiments are also discussed in ten-ns of the traffic maneuver stereotypes exhibited by the pilots. Experiment 3 examined the benefits of the two different predictor elements used in the coplanar displays of Experiments 1 and 2. The study was carried out in a multitask context. These elements were both found to improve safety (reduce actual and predicted conflicts) and to reduce workload, although the different elements affected workload in different ways. Neither predictor element imposed a cost to concurrent task performance.

  17. Learning in shifts of transient attention improves recognition of parts of ambiguous figure-ground displays.

    Science.gov (United States)

    Kristjánsson, Arni

    2009-04-24

    Previously demonstrated learning effects in shifts of transient attention have only been shown to result in beneficial effects upon secondary discrimination tasks and affect landing points of express saccades. Can such learning result in more direct effects upon perception than previously demonstrated? Observers performed a cued Vernier acuity discrimination task where the cue was one of a set of ambiguous figure-ground displays (with a black and white part). The critical measure was whether, if a target appeared consistently within a part of a cue of a certain brightness, this would result in learning effects and whether such learning would then affect recognition of the cue parts. Critically the target always appeared within the same part of each individual cue. Some cues were used in early parts of streaks of repetition of cue-part brightness, and others in latter parts of such streaks. All the observers showed learning in shifts of transient attention, with improved performance the more often the target appeared within the part of the cue of the same brightness. Subsequently the observers judged whether cue-parts had been parts of the cues used on the preceding discrimination task. Recognition of the figure parts, where the target had consistently appeared, improved strongly with increased length of streaks of repetition of cue-part brightness. Learning in shifts of transient attention leads not only to faster attention shifts but to direct effects upon perception, in this case recognition of parts of figure-ground ambiguous cues.

  18. Collision Avoidance for Airport Traffic Concept Evaluation

    Science.gov (United States)

    Jones, Denise R.; Prinzel, Lawrence J., III; Otero, Sharon D.; Barker, Glover D.

    2009-01-01

    An initial Collision Avoidance for Airport Traffic (CAAT) concept for the Terminal Maneuvering Area (TMA) was evaluated in a simulation study at the National Aeronautics and Space Administration (NASA) Langley Research Center. CAAT is being designed to enhance surface situation awareness and provide cockpit alerts of potential conflicts during runway, taxi, and low altitude air-to-air operations. The purpose of the study was to evaluate the initial concept for an aircraft-based method of conflict detection and resolution (CD&R) in the TMA focusing on conflict detection algorithms and alerting display concepts. This paper gives an overview of the CD&R concept, simulation study, and test results.

  19. Handheld Microneedle-Based Electrolyte Sensing Platform.

    Energy Technology Data Exchange (ETDEWEB)

    Miller, Philip R. [Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States); Rivas, Rhiana [Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States); Johnson, David [Aquila Technologies Group, Inc., Albuquerque, NM (United States); Edwards, Thayne L. [Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States); Koskelo, Markku [Aquila Technologies Group, Inc., Albuquerque, NM (United States); Shawa, Luay [Aquila Technologies Group, Inc., Albuquerque, NM (United States); Brener, Igal [Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States); Chavez, Victor H. [Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States); Polsky, Ronen [Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States)

    2015-11-01

    Sandia National Laboratories will provide technical assistance, within time and budget, to Requester on testing and analyzing a microneedle-based electrolyte sensing platform. Hollow microneedles will be fabricated at Sandia and integrated with a fluidic chip using plastic laminate prototyping technology available at Sandia. In connection with commercial ion selective electrodes the sensing platform will be tested for detection of electrolytes (sodium and/or potassium) within physiological relevant concent ration ranges.

  20. Dimensions of Situatedness for Digital Public Displays

    Directory of Open Access Journals (Sweden)

    Rui José

    2014-01-01

    Full Text Available Public displays are often strongly situated signs deeply embedded in their physical, social, and cultural setting. Understanding how the display is coupled with on-going situations, its level of situatedness, provides a key element for the interpretation of the displays themselves but is also an element for the interpretation of place, its situated practices, and its social context. Most digital displays, however, do not achieve the same sense of situatedness that seems so natural in their nondigital counterparts. This paper investigates people’s perception of situatedness when considering the connection between public displays and their context. We have collected over 300 photos of displays and conducted a set of analysis tasks involving focus groups and structured interviews with 15 participants. The contribution is a consolidated list of situatedness dimensions that should provide a valuable resource for reasoning about situatedness in digital displays and informing the design and development of display systems.

  1. Integration of a satellite ground support system based on analysis of the satellite ground support domain

    Science.gov (United States)

    Pendley, R. D.; Scheidker, E. J.; Levitt, D. S.; Myers, C. R.; Werking, R. D.

    1994-11-01

    This analysis defines a complete set of ground support functions based on those practiced in real space flight operations during the on-orbit phase of a mission. These functions are mapped against ground support functions currently in use by NASA and DOD. Software components to provide these functions can be hosted on RISC-based work stations and integrated to provide a modular, integrated ground support system. Such modular systems can be configured to provide as much ground support functionality as desired. This approach to ground systems has been widely proposed and prototyped both by government institutions and commercial vendors. The combined set of ground support functions we describe can be used as a standard to evaluate candidate ground systems. This approach has also been used to develop a prototype of a modular, loosely-integrated ground support system, which is discussed briefly. A crucial benefit to a potential user is that all the components are flight-qualified, thus giving high confidence in their accuracy and reliability.

  2. Overview of Boundary Layer Clouds Using Satellite and Ground-Based Measurements

    Science.gov (United States)

    Xi, B.; Dong, X.; Wu, P.; Qiu, S.

    2017-12-01

    A comprehensive summary of boundary layer clouds properties based on our few recently studies will be presented. The analyses include the global cloud fractions and cloud macro/micro- physical properties based on satellite measurements using both CERES-MODIS and CloudSat/Caliposo data products,; the annual/seasonal/diurnal variations of stratocumulus clouds over different climate regions (mid-latitude land, mid-latitude ocean, and Arctic region) using DOE ARM ground-based measurements over Southern great plain (SGP), Azores (GRW), and North slope of Alaska (NSA) sites; the impact of environmental conditions to the formation and dissipation process of marine boundary layer clouds over Azores site; characterizing Arctice mixed-phase cloud structure and favorable environmental conditions for the formation/maintainess of mixed-phase clouds over NSA site. Though the presentation has widely spread topics, we will focus on the representation of the ground-based measurements over different climate regions; evaluation of satellite retrieved cloud properties using these ground-based measurements, and understanding the uncertainties of both satellite and ground-based retrievals and measurements.

  3. Advancements in Modelling of Land Surface Energy Fluxes with Remote Sensing at Different Spatial Scales

    DEFF Research Database (Denmark)

    Guzinski, Radoslaw

    uxes, such as sensible heat ux, ground heat ux and net radiation, are also necessary. While it is possible to measure those uxes with ground-based instruments at local scales, at region scales they usually need to be modelled or estimated with the help of satellite remote sensing data. Even though...... to increase the spatial resolution of the reliable DTD-modelled fluxes from 1 km to 30 m. Furthermore, synergies between remote sensing based models and distributed hydrological models were studied with the aim of improving spatial performance of the hydrological models through incorporation of remote sensing...... of this study was to look at, and improve, various approaches for modelling the land-surface energy uxes at different spatial scales. The work was done using physically-based Two-Source Energy Balance (TSEB) approach as well as semi-empirical \\Triangle" approach. The TSEB-based approach was the main focus...

  4. Polarimetric Remote Sensing of Atmospheric Particulate Pollutants

    Science.gov (United States)

    Li, Z.; Zhang, Y.; Hong, J.

    2018-04-01

    Atmospheric particulate pollutants not only reduce atmospheric visibility, change the energy balance of the troposphere, but also affect human and vegetation health. For monitoring the particulate pollutants, we establish and develop a series of inversion algorithms based on polarimetric remote sensing technology which has unique advantages in dealing with atmospheric particulates. A solution is pointed out to estimate the near surface PM2.5 mass concentrations from full remote sensing measurements including polarimetric, active and infrared remote sensing technologies. It is found that the mean relative error of PM2.5 retrieved by full remote sensing measurements is 35.5 % in the case of October 5th 2013, improved to a certain degree compared to previous studies. A systematic comparison with the ground-based observations further indicates the effectiveness of the inversion algorithm and reliability of results. A new generation of polarized sensors (DPC and PCF), whose observation can support these algorithms, will be onboard GF series satellites and launched by China in the near future.

  5. Hanford ground-water data base management guide and user's manual

    International Nuclear Information System (INIS)

    Mitchell, P.J.; Argo, R.S.; Bradymire, S.L.; Newbill, C.A.

    1985-05-01

    This management guide and user's manual is a working document for the computerized Hanford Ground-water Data Base maintained by the Geosciences Research and Engineering Department at Pacific Northwest Laboratory for the Hanford Ground-Water Surveillance Program. The program is managed by the Occupational and Environmental Protection Department for the US Department of Energy. The data base is maintained to provide rapid access to data that are rountinely collected from ground-water monitoring wells at the Hanford site. The data include water levels, sample analyses, geologic descriptions and well construction information of over 3000 existing or destroyed wells. These data are used to monitor water quality and for the evaluation of ground-water flow and pollutant transport problems. The management guide gives instructions for maintenance of the data base on the Digital Equipment Corporation PDP 11/70 Computer using the CIRMIS (Comprehensive Information Retrieval and Model Input Sequence) data base management software developed at Pacific Northwest Laboratory. Maintenance activities include inserting, modifying and deleting data, making back-up copies of the data base, and generating tables for annual monitoring reports. The user's guide includes instructions for running programs to retrieve the data in the form of listings of graphical plots. 3 refs

  6. Remote-Sensing Time Series Analysis, a Vegetation Monitoring Tool

    Science.gov (United States)

    McKellip, Rodney; Prados, Donald; Ryan, Robert; Ross, Kenton; Spruce, Joseph; Gasser, Gerald; Greer, Randall

    2008-01-01

    The Time Series Product Tool (TSPT) is software, developed in MATLAB , which creates and displays high signal-to- noise Vegetation Indices imagery and other higher-level products derived from remotely sensed data. This tool enables automated, rapid, large-scale regional surveillance of crops, forests, and other vegetation. TSPT temporally processes high-revisit-rate satellite imagery produced by the Moderate Resolution Imaging Spectroradiometer (MODIS) and by other remote-sensing systems. Although MODIS imagery is acquired daily, cloudiness and other sources of noise can greatly reduce the effective temporal resolution. To improve cloud statistics, the TSPT combines MODIS data from multiple satellites (Aqua and Terra). The TSPT produces MODIS products as single time-frame and multitemporal change images, as time-series plots at a selected location, or as temporally processed image videos. Using the TSPT program, MODIS metadata is used to remove and/or correct bad and suspect data. Bad pixel removal, multiple satellite data fusion, and temporal processing techniques create high-quality plots and animated image video sequences that depict changes in vegetation greenness. This tool provides several temporal processing options not found in other comparable imaging software tools. Because the framework to generate and use other algorithms is established, small modifications to this tool will enable the use of a large range of remotely sensed data types. An effective remote-sensing crop monitoring system must be able to detect subtle changes in plant health in the earliest stages, before the effects of a disease outbreak or other adverse environmental conditions can become widespread and devastating. The integration of the time series analysis tool with ground-based information, soil types, crop types, meteorological data, and crop growth models in a Geographic Information System, could provide the foundation for a large-area crop-surveillance system that could identify

  7. Remote Sensing of Landslides—A Review

    Directory of Open Access Journals (Sweden)

    Chaoying Zhao

    2018-02-01

    Full Text Available Triggered by earthquakes, rainfall, or anthropogenic activities, landslides represent widespread and problematic geohazards worldwide. In recent years, multiple remote sensing techniques, including synthetic aperture radar, optical, and light detection and ranging measurements from spaceborne, airborne, and ground-based platforms, have been widely applied for the analysis of landslide processes. Current techniques include landslide detection, inventory mapping, surface deformation monitoring, trigger factor analysis and mechanism inversion. In addition, landslide susceptibility modelling, hazard assessment, and risk evaluation can be further analyzed using a synergic fusion of multiple remote sensing data and other factors affecting landslides. We summarize the 19 articles collected in this special issue of Remote Sensing of Landslide, in the terms of data, methods and applications used in the papers.

  8. Terminal weather information management

    Science.gov (United States)

    Lee, Alfred T.

    1990-01-01

    Since the mid-1960's, microburst/windshear events have caused at least 30 aircraft accidents and incidents and have killed more than 600 people in the United States alone. This study evaluated alternative means of alerting an airline crew to the presence of microburst/windshear events in the terminal area. Of particular interest was the relative effectiveness of conventional and data link ground-to-air transmissions of ground-based radar and low-level windshear sensing information on microburst/windshear avoidance. The Advanced Concepts Flight Simulator located at Ames Research Center was employed in a line oriented simulation of a scheduled round-trip airline flight from Salt Lake City to Denver Stapleton Airport. Actual weather en route and in the terminal area was simulated using recorded data. The microburst/windshear incident of July 11, 1988 was re-created for the Denver area operations. Six experienced airline crews currently flying scheduled routes were employed as test subjects for each of three groups: (1) A baseline group which received alerts via conventional air traffic control (ATC) tower transmissions; (2) An experimental group which received alerts/events displayed visually and aurally in the cockpit six miles (approx. 2 min.) from the microburst event; and (3) An additional experimental group received displayed alerts/events 23 linear miles (approx. 7 min.) from the microburst event. Analyses of crew communications and decision times showed a marked improvement in both situation awareness and decision-making with visually displayed ground-based radar information. Substantial reductions in the variability of decision times among crews in the visual display groups were also found. These findings suggest that crew performance will be enhanced and individual differences among crews due to differences in training and prior experience are significantly reduced by providing real-time, graphic display of terminal weather hazards.

  9. Progress in Analysis to Remote Sensed Thermal Abnormity with Fault Activity and Seismogenic Process

    Directory of Open Access Journals (Sweden)

    WU Lixin

    2017-10-01

    Full Text Available Research to the remote sensed thermal abnormity with fault activity and seismogenic process is a vital topic of the Earth observation and remote sensing application. It is presented that a systematic review on the international researches on the topic during the past 30 years, in the respects of remote sensing data applications, anomaly analysis methods, and mechanism understanding. Firstly, the outlines of remote sensing data applications are given including infrared brightness temperature, microwave brightness temperature, outgoing longwave radiation, and assimilated data from multiple earth observations. Secondly, three development phases are summarized as qualitative analysis based on visual interpretation, quantitative analysis based on image processing, and multi-parameter spatio-temporal correlation analysis. Thirdly, the theoretical hypotheses presented for the mechanism understanding are introduced including earth degassing, stress-induced heat, crustal rock battery conversion, latent heat release due to radon decay as well as multi-spheres coupling effect. Finally, three key directions of future research on this topic are proposed:anomaly recognizing by remote sensing monitoring and data analysis for typical tectonic activity areas; anomaly mechanism understanding based on earthquake-related earth system responses; spatio-temporal correlation analysis of air-based, space-based and ground-based stereoscopic observations.

  10. Simulation of Ground-Water Flow and Effects of Ground-Water Irrigation on Base Flow in the Elkhorn and Loup River Basins, Nebraska

    Science.gov (United States)

    Peterson, Steven M.; Stanton, Jennifer S.; Saunders, Amanda T.; Bradley, Jesse R.

    2008-01-01

    Irrigated agriculture is vital to the livelihood of communities in the Elkhorn and Loup River Basins in Nebraska, and ground water is used to irrigate most of the cropland. Concerns about the sustainability of ground-water and surface-water resources have prompted State and regional agencies to evaluate the cumulative effects of ground-water irrigation in this area. To facilitate understanding of the effects of ground-water irrigation, a numerical computer model was developed to simulate ground-water flow and assess the effects of ground-water irrigation (including ground-water withdrawals, hereinafter referred to as pumpage, and enhanced recharge) on stream base flow. The study area covers approximately 30,800 square miles, and includes the Elkhorn River Basin upstream from Norfolk, Nebraska, and the Loup River Basin upstream from Columbus, Nebraska. The water-table aquifer consists of Quaternary-age sands and gravels and Tertiary-age silts, sands, and gravels. The simulation was constructed using one layer with 2-mile by 2-mile cell size. Simulations were constructed to represent the ground-water system before 1940 and from 1940 through 2005, and to simulate hypothetical conditions from 2006 through 2045 or 2055. The first simulation represents steady-state conditions of the system before anthropogenic effects, and then simulates the effects of early surface-water development activities and recharge of water leaking from canals during 1895 to 1940. The first simulation ends at 1940 because before that time, very little pumpage for irrigation occurred, but after that time it became increasingly commonplace. The pre-1940 simulation was calibrated against measured water levels and estimated long-term base flow, and the 1940 through 2005 simulation was calibrated against measured water-level changes and estimated long-term base flow. The calibrated 1940 through 2005 simulation was used as the basis for analyzing hypothetical scenarios to evaluate the effects of

  11. Color Difference Threshold of Chromostereopsis Induced by Flat Display Emission

    Directory of Open Access Journals (Sweden)

    Maris eOzolinsh

    2015-04-01

    Full Text Available The study of chromostereopsis has gained attention in the backdrop of the use of computer displays in daily life. In this context, we analyze the illusory depth sense using planar color images presented on a computer screen. We determine the color difference threshold required to induce an illusory sense of depth psychometrically using a constant stimuli paradigm. Isoluminant stimuli are presented on a computer screen, which stimuli are aligned along the blue-red line in the computer display CIE xyY color chart. Stereo disparity is generated by increasing the color difference between the central and surrounding areas of the stimuli with both areas consisting of random dots on a black background. The observed altering of illusory dept sense, thus also stereo disparity is validated using the center-of-gravity model. The induced illusory sense of the depth effect undergoes color reversal upon varying the binocular lateral eye pupil covering conditions (lateral or medial. Analysis of the retinal image point spread function for the display red and blue pixel radiation validates the altering of chromostereopsis retinal disparity achieved by increasing the color difference, and also the chromostereopsis color reversal caused by varying the eye pupil covering conditions.

  12. Research on Intelligent Avoidance Method of Shipwreck Based on Bigdata Analysis

    Directory of Open Access Journals (Sweden)

    Li Wei

    2017-11-01

    Full Text Available In order to solve the problem that current avoidance method of shipwreck has the problem of low success rate of avoidance, this paper proposes a method of intelligent avoidance of shipwreck based on big data analysis. Firstly,our method used big data analysis to calculate the safe distance of approach of ship under the head-on situation, the crossing situation and the overtaking situation.On this basis, by calculating the risk-degree of collision of ships,our research determined the degree of immediate danger of ships.Finally, we calculated the three kinds of evaluation function of ship navigation, and used genetic algorithm to realize the intelligent avoidance of shipwreck.Experimental result shows that compared the proposed method with the traditional method in two in a recent meeting when the distance to closest point of approach between two ships is 0.13nmile, they can effectively evade.The success rate of avoidance is high.

  13. Avoidance orientation and the escalation of negative communication in intimate relationships.

    Science.gov (United States)

    Kuster, Monika; Bernecker, Katharina; Backes, Sabine; Brandstätter, Veronika; Nussbeck, Fridtjof W; Bradbury, Thomas N; Martin, Mike; Sutter-Stickel, Dorothee; Bodenmann, Guy

    2015-08-01

    Avoidance goals heighten the salience of negative social experiences, and in intimate relationships such an orientation may contribute to communication difficulties and the perpetuation of avoidance. We therefore hypothesized that individuals with stronger avoidance goals would be particularly prone to engage in escalating levels of negative communication with their intimate partner, and we tested this prediction by conducting sequential analyses on videotaped observational data (28,470 observations) collected from 365 heterosexual couples engaging in a relationship-related conflict. While less avoidance-oriented spouses showed a decline in their likelihood of negative communication over the course of the 8-min conflict discussion, the likelihood that more avoidance-oriented spouses would display negative communication behaviors remained at a high level. The likelihood of negative communication even increased when avoidance-oriented spouses were confronted with negative communication behavior of their partners. The effects of avoidance orientation were independent of relationship satisfaction and neuroticism. These findings demonstrate that avoidance goals underlie individuals' heightened reactivity to the partner's negative behavior, while also clarifying 1 possible reason why some individuals engage in communication behaviors that may prove maladaptive to their relationship. (c) 2015 APA, all rights reserved.

  14. The COROT ground-based archive and access system

    Science.gov (United States)

    Solano, E.; González-Riestra, R.; Catala, C.; Baglin, A.

    2002-01-01

    A prototype of the COROT ground-based archive and access system is presented here. The system has been developed at LAEFF and it is based on the experience gained at Laboratorio de Astrofisica Espacial y Fisica Fundamental (LAEFF) with the INES (IUE Newly Extracted System) Archive.

  15. Active Ground Optical Remote Sensing for Improved Monitoring of Seedling Stress in Nurseries

    Directory of Open Access Journals (Sweden)

    Jan U. H. Eitel

    2010-03-01

    Full Text Available Active ground optical remote sensing (AGORS devices mounted on overhead irrigation booms could help to improve seedling quality by autonomously monitoring seedling stress. In contrast to traditionally used passive optical sensors, AGORS devices operate independently of ambient light conditions and do not require spectral reference readings. Besides measuring red (590–670 nm and near-infrared (>760 nm reflectance AGORS devices have recently become available that also measure red-edge (730 nm reflectance. We tested the hypothesis that the additional availability of red-edge reflectance information would improve AGORS of plant stress induced chlorophyll breakdown in Scots pine (Pinus sylvestris. Our results showed that the availability of red-edge reflectance information improved AGORS estimates of stress induced variation in chlorophyll concentration (r2 > 0.73, RMSE < 1.69 when compared to those without (r2 = 0.57, RMSE = 2.11.

  16. Remote Sensing and Special Surveys Program annual report, January--December 1993

    International Nuclear Information System (INIS)

    Conder, S.R.; Doll, W.E.; Gabrielsen, C.A.; King, A.D.; Durfee, R.C.; Parr, P.D.

    1994-03-01

    The Remote Sensing and Special Surveys Program has been established to provide environmental characterization data, change data, and trend data to various Environmental Restoration and Waste Management (ERWM) programs. The data are acquired through several different types of survey platforms. During the calendar year of 1993, a variety of surveys were conducted through the Remote Sensing and Special Surveys Program. The aerial surveys included geophysical, radiological, false color infrared (IR) photography, and natural color photography. Ground surveys were conducted to correlate data collected from the airborne platforms to data measured at ground level. Ground surveys were also conducted to determine the existence or absence of threatened and endangered plant species on the Oak Ridge Reservation. Some of the special surveys included laser induced fluorescence imaging, solar reflectance, and various remote sensing and ground control activities for the Strategic Environmental Research and Development Program (SERDP) initiative. Data analysis, management, and storage are also conducted by the Remote Sensing and Special Surveys Program to achieve the highest level of data useability possible. The data acquired through these surveys have provided and will continue to provide much needed information to ERWM programs

  17. Multi-wavelengths digital holography: reconstruction, synthesis and display of holograms using adaptive transformation.

    Science.gov (United States)

    Memmolo, P; Finizio, A; Paturzo, M; Ferraro, P; Javidi, B

    2012-05-01

    A method based on spatial transformations of multiwavelength digital holograms and the correlation matching of their numerical reconstructions is proposed, with the aim to improve superimposition of different color reconstructed images. This method is based on an adaptive affine transform of the hologram that permits management of the physical parameters of numerical reconstruction. In addition, we present a procedure to synthesize a single digital hologram in which three different colors are multiplexed. The optical reconstruction of the synthetic hologram by a spatial light modulator at one wavelength allows us to display all color features of the object, avoiding loss of details.

  18. Scanning fiber microdisplay: design, implementation, and comparison to MEMS mirror-based scanning displays.

    Science.gov (United States)

    Khayatzadeh, Ramin; Civitci, Fehmi; Ferhanoglu, Onur; Urey, Hakan

    2018-03-05

    In this study, we propose a compact, lightweight scanning fiber microdisplay towards virtual and augmented reality applications. Our design that is tailored as a head-worn-display simply consists of a four-quadrant piezoelectric tube actuator through which a fiber optics cable is extended and actuated, and a reflective (or semi-reflective) ellipsoidal surface that relays the moving tip of the fiber onto the viewer's retina. The proposed display, offers significant advantages in terms of architectural simplicity, form-factor, fabrication complexity and cost over other fiber scanner and MEMS mirror counterparts towards practical realization. We demonstrate the display of various patterns with ∼VGA resolution and further provide analytical formulas for mechanical and optical constraints to compare the performance of the proposed scanning fiber microdisplay with that of MEMS mirror-based microdisplays. Also we discuss the road steps towards improving the performance of the proposed scanning fiber microdisplay to high-definition video formats (such as HD1440), which is beyond what has been achieved by MEMS mirror based laser scanning displays.

  19. Remote sensing of sagebrush canopy nitrogen

    Science.gov (United States)

    Mitchell, Jessica J.; Glenn, Nancy F.; Sankey, Temuulen T.; Derryberry, DeWayne R.; Germino, Matthew J.

    2012-01-01

    This paper presents a combination of techniques suitable for remotely sensing foliar Nitrogen (N) in semiarid shrublands – a capability that would significantly improve our limited understanding of vegetation functionality in dryland ecosystems. The ability to estimate foliar N distributions across arid and semi-arid environments could help answer process-driven questions related to topics such as controls on canopy photosynthesis, the influence of N on carbon cycling behavior, nutrient pulse dynamics, and post-fire recovery. Our study determined that further exploration into estimating sagebrush canopy N concentrations from an airborne platform is warranted, despite remote sensing challenges inherent to open canopy systems. Hyperspectral data transformed using standard derivative analysis were capable of quantifying sagebrush canopy N concentrations using partial least squares (PLS) regression with an R2 value of 0.72 and an R2 predicted value of 0.42 (n = 35). Subsetting the dataset to minimize the influence of bare ground (n = 19) increased R2 to 0.95 (R2 predicted = 0.56). Ground-based estimates of canopy N using leaf mass per unit area measurements (LMA) yielded consistently better model fits than ground-based estimates of canopy N using cover and height measurements. The LMA approach is likely a method that could be extended to other semiarid shrublands. Overall, the results of this study are encouraging for future landscape scale N estimates and represent an important step in addressing the confounding influence of bare ground, which we found to be a major influence on predictions of sagebrush canopy N from an airborne platform.

  20. A hierarchic approach for examining panarctic vegeta0on with a focus on the linkages between remote-sensing and plot-based studies: A prototype example from Toolik Lake, Alaska

    DEFF Research Database (Denmark)

    Walker, D.A.; Bhatt, U.S.; Breen, A.L.

    A circumpolar view of Arctic vegetation developed with the advent of satellite-derived remote-sensing products. Interpretations of what the revealed patterns mean are dependent on a foundation of in-situ plot-based observations. Despite the importance of ground-based observations, only a few areas...... of species composition, canopy structure, biomass, leaf-area index, and NDVI, along with high-resolution satellite-based remote-sensing products at the same time....... classification, plot markings, and standardized approaches to describe the local environment, including photo points showing the vegetation and soils up close and in landscape view. (3) Standardized approaches for collecting in-situ time-series of spectral data. Standardized methods for collecting and analyzing...

  1. Multicanonical simulation of the Domb-Joyce model and the Gō model: new enumeration methods for self-avoiding walks

    International Nuclear Information System (INIS)

    Shirai, Nobu C; Kikuchi, Macoto

    2013-01-01

    We develop statistical enumeration methods for self-avoiding walks using a powerful sampling technique called the multicanonical Monte Carlo method. Using these methods, we estimate the numbers of the two dimensional N-step self-avoiding walks up to N = 256 with statistical errors. The developed methods are based on statistical mechanical models of paths which include self-avoiding walks. The criterion for selecting a suitable model for enumerating self-avoiding walks is whether or not the configuration space of the model includes a set for which the number of the elements can be exactly counted. We call this set a scale fixing set. We selected the following two models which satisfy the criterion: the Gō model for lattice proteins and the Domb-Joyce model for generalized random walks. There is a contrast between these two models in the structures of the configuration space. The configuration space of the Gō model is defined as the universal set of self-avoiding walks, and the set of the ground state conformation provides a scale fixing set. On the other hand, the configuration space of the Domb-Joyce model is defined as the universal set of random walks which can be used as a scale fixing set, and the set of the ground state conformation is the same as the universal set of self-avoiding walks. From the perspective of enumeration performance, we conclude that the Domb-Joyce model is the better of the two. The reason for the performance difference is partly explained by the existence of the first-order phase transition of the Gō model

  2. Exogenous spatial attention influences figure-ground assignment.

    Science.gov (United States)

    Vecera, Shaun P; Flevaris, Anastasia V; Filapek, Joseph C

    2004-01-01

    In a hierarchical stage account of vision, figure-ground assignment is thought to be completed before the operation of focal spatial attention. Results of previous studies have supported this account by showing that unpredictive, exogenous spatial precues do not influence figure-ground assignment, although voluntary attention can influence figure-ground assignment. However, in these studies, attention was not summoned directly to a region in a figure-ground display. In three experiments, we addressed the relationship between figure-ground assignment and visuospatial attention. In Experiment 1, we replicated the finding that exogenous precues do not influence figure-ground assignment when they direct attention outside of a figure-ground stimulus. In Experiment 2, we demonstrated that exogenous attention can influence figure-ground assignment if it is directed to one of the regions in a figure-ground stimulus. In Experiment 3, we demonstrated that exogenous attention can influence figure-ground assignment in displays that contain a Gestalt figure-ground cue; this result suggests that figure-ground processes are not entirely completed prior to the operation of focal spatial attention. Exogenous spatial attention acts as a cue for figure-ground assignment and can affect the outcome of figure-ground processes.

  3. Optical/Infrared Signatures for Space-Based Remote Sensing

    National Research Council Canada - National Science Library

    Picard, R. H; Dewan, E. M; Winick, J. R; O'Neil, R. R

    2007-01-01

    This report describes work carried out under the Air Force Research Laboratory's basic research task in optical remote-sensing signatures, entitled Optical / Infrared Signatures for Space-Based Remote Sensing...

  4. A Data-Gathering Scheme with Joint Routing and Compressive Sensing Based on Modified Diffusion Wavelets in Wireless Sensor Networks.

    Science.gov (United States)

    Gu, Xiangping; Zhou, Xiaofeng; Sun, Yanjing

    2018-02-28

    Compressive sensing (CS)-based data gathering is a promising method to reduce energy consumption in wireless sensor networks (WSNs). Traditional CS-based data-gathering approaches require a large number of sensor nodes to participate in each CS measurement task, resulting in high energy consumption, and do not guarantee load balance. In this paper, we propose a sparser analysis that depends on modified diffusion wavelets, which exploit sensor readings' spatial correlation in WSNs. In particular, a novel data-gathering scheme with joint routing and CS is presented. A modified ant colony algorithm is adopted, where next hop node selection takes a node's residual energy and path length into consideration simultaneously. Moreover, in order to speed up the coverage rate and avoid the local optimal of the algorithm, an improved pheromone impact factor is put forward. More importantly, theoretical proof is given that the equivalent sensing matrix generated can satisfy the restricted isometric property (RIP). The simulation results demonstrate that the modified diffusion wavelets' sparsity affects the sensor signal and has better reconstruction performance than DFT. Furthermore, our data gathering with joint routing and CS can dramatically reduce the energy consumption of WSNs, balance the load, and prolong the network lifetime in comparison to state-of-the-art CS-based methods.

  5. Remote Sensing of the Heliospheric Solar Wind using Radio ...

    Indian Academy of Sciences (India)

    tribpo

    Astr. (2000) 21, 439–444. Remote Sensing of the Heliospheric Solar Wind using Radio. Astronomy Methods and Numerical Simulations. S. Ananthakrishnan, National Center for Radio Astrophysics, Tata Institute of. Fundamental Research, Pune, India. Abstract. The ground-based radio astronomy method of interplanetary.

  6. A Gloss Composition and Context Clustering Based Distributed Word Sense Representation Model

    Directory of Open Access Journals (Sweden)

    Tao Chen

    2015-08-01

    Full Text Available In recent years, there has been an increasing interest in learning a distributed representation of word sense. Traditional context clustering based models usually require careful tuning of model parameters, and typically perform worse on infrequent word senses. This paper presents a novel approach which addresses these limitations by first initializing the word sense embeddings through learning sentence-level embeddings from WordNet glosses using a convolutional neural networks. The initialized word sense embeddings are used by a context clustering based model to generate the distributed representations of word senses. Our learned representations outperform the publicly available embeddings on half of the metrics in the word similarity task, 6 out of 13 sub tasks in the analogical reasoning task, and gives the best overall accuracy in the word sense effect classification task, which shows the effectiveness of our proposed distributed distribution learning model.

  7. Efficient crop type mapping based on remote sensing in the Central Valley, California

    Science.gov (United States)

    Zhong, Liheng

    Most agricultural systems in California's Central Valley are purposely flexible and intentionally designed to meet the demands of dynamic markets. Agricultural land use is also impacted by climate change and urban development. As a result, crops change annually and semiannually, which makes estimating agricultural water use difficult, especially given the existing method by which agricultural land use is identified and mapped. A minor portion of agricultural land is surveyed annually for land-use type, and every 5 to 8 years the entire valley is completely evaluated. So far no effort has been made to effectively and efficiently identify specific crop types on an annual basis in this area. The potential of satellite imagery to map agricultural land cover and estimate water usage in the Central Valley is explored. Efforts are made to minimize the cost and reduce the time of production during the mapping process. The land use change analysis shows that a remote sensing based mapping method is the only means to map the frequent change of major crop types. The traditional maximum likelihood classification approach is first utilized to map crop types to test the classification capacity of existing algorithms. High accuracy is achieved with sufficient ground truth data for training, and crop maps of moderate quality can be timely produced to facilitate a near-real-time water use estimate. However, the large set of ground truth data required by this method results in high costs in data collection. It is difficult to reduce the cost because a trained classification algorithm is not transferable between different years or different regions. A phenology based classification (PBC) approach is developed which extracts phenological metrics from annual vegetation index profiles and identifies crop types based on these metrics using decision trees. According to the comparison with traditional maximum likelihood classification, this phenology-based approach shows great advantages

  8. Development and verification of ground-based tele-robotics operations concept for Dextre

    Science.gov (United States)

    Aziz, Sarmad

    2013-05-01

    The Special Purpose Dextreous Manipulator (Dextre) is the latest addition to the on-orbit segment of the Mobile Servicing System (MSS); Canada's contribution to the International Space Station (ISS). Launched in March 2008, the advanced two-armed robot is designed to perform various ISS maintenance tasks on robotically compatible elements and on-orbit replaceable units using a wide variety of tools and interfaces. The addition of Dextre has increased the capabilities of the MSS, and has introduced significant complexity to ISS robotics operations. While the initial operations concept for Dextre was based on human-in-the-loop control by the on-orbit astronauts, the complexities of robotic maintenance and the associated costs of training and maintaining the operator skills required for Dextre operations demanded a reexamination of the old concepts. A new approach to ISS robotic maintenance was developed in order to utilize the capabilities of Dextre safely and efficiently, while at the same time reducing the costs of on-orbit operations. This paper will describe the development, validation, and on-orbit demonstration of the operations concept for ground-based tele-robotics control of Dextre. It will describe the evolution of the new concepts from the experience gained from the development and implementation of the ground control capability for the Space Station Remote Manipulator System; Canadarm 2. It will discuss the various technical challenges faced during the development effort, such as requirements for high positioning accuracy, force/moment sensing and accommodation, failure tolerance, complex tool operations, and the novel operational tools and techniques developed to overcome them. The paper will also describe the work performed to validate the new concepts on orbit and will discuss the results and lessons learned from the on-orbit checkout and commissioning of Dextre using the newly developed tele-robotics techniques and capabilities.

  9. Remote sensing of natural resources. Quarterly literature review, October-December 1980

    International Nuclear Information System (INIS)

    Gonzales, R.W.; Inglis, M.H.

    1981-02-01

    This review covers literature pertaining to documented data and data gathering techniques that are performed or obtained remotely from space, aircraft, or ground-based stations. All of the documentation is related to remote sensing sensors or the remote sensing of the natural resources. Section headings are: general; geology; environmental quality; hydrology; vegetation; oceanography; regional planning and land use; data manipulation; and instrumentation and technology

  10. An Integration of Ground-Penetrating Radar, Remote Sensing, and Discharge Records of the Modern Kicking Horse River, BC

    Science.gov (United States)

    Cyples, N.; Ielpi, A.; Dirszowsky, R.

    2017-12-01

    The Kicking Horse River is a gravel-bed stream originating from glacial meltwater supplied by the Wapta Icefields in south-eastern British Columbia. An alluvial tract extends for 7 km through Field, BC, where the trunk channel undergoes diurnal and seasonal fluctuations in flow as a result of varying glacial-meltwater supply and runoff recharge. Prior studies erected the Kicking Horse River as a reference for proximal braided systems, and documented bar formation and sediment distribution patterns from ground observations. However, a consistent model of planform evolution and related stratigraphic signature is lacking. Specific objectives of this study are to examine the morphodynamic evolution and stratigraphic signature of channel-bar complexes using high-resolution satellite imagery, sedimentologic and discharge observations, and ground-penetrating radar (GPR). Remote sensing highlights rates of lateral channel migration of as much as 270 meters over eight years ( 34 meters/year), and demonstrates how flood stages are associated with stepwise episodes of channel braiding and anabranching. GPR analysis aided in the identification of five distinct radar facies, including: discontinuous, inclined, planar, trough-shaped, and mounded reflectors, which were respectively related to specific architectural elements and fluvial processes responsible for bar evolution. Across-stream GPR transects demonstrated higher heterogeneity in facies distribution, while downstream-oriented transects yielded a more monotonous distribution in radar facies. Notably, large-scale inclined reflectors related to step-wise bar accretion are depicted only in downstream-oriented transects, while discontinuous reflectors related to bedform stacking appear to be dominant in along-stream transects. Integration of sedimentological data with remote sensing, gauging records, and GPR analysis allows for high-resolution modelling of stepwise changes in alluvial morphology. Conceptual models stemming

  11. Urban land use: Remote sensing of ground-basin permeability

    Science.gov (United States)

    Tinney, L. R.; Jensen, J. R.; Estes, J. E.

    1975-01-01

    A remote sensing analysis of the amount and type of permeable and impermeable surfaces overlying an urban recharge basin is discussed. An effective methodology for accurately generating this data as input to a safe yield study is detailed and compared to more conventional alternative approaches. The amount of area inventoried, approximately 10 sq. miles, should provide a reliable base against which automatic pattern recognition algorithms, currently under investigation for this task, can be evaluated. If successful, such approaches can significantly reduce the time and effort involved in obtaining permeability data, an important aspect of urban hydrology dynamics.

  12. Six-Port Based Interferometry for Precise Radar and Sensing Applications

    Directory of Open Access Journals (Sweden)

    Alexander Koelpin

    2016-09-01

    Full Text Available Microwave technology plays a more important role in modern industrial sensing applications. Pushed by the significant progress in monolithic microwave integrated circuit technology over the past decades, complex sensing systems operating in the microwave and even millimeter-wave range are available for reasonable costs combined with exquisite performance. In the context of industrial sensing, this stimulates new approaches for metrology based on microwave technology. An old measurement principle nearly forgotten over the years has recently gained more and more attention in both academia and industry: the six-port interferometer. This paper reviews the basic concept, investigates promising applications in remote, as well as contact-based sensing and compares the system with state-of-the-art metrology. The significant advantages will be discussed just as the limitations of the six-port architecture. Particular attention will be paid to impairment effects and non-ideal behavior, as well as compensation and linearization concepts. It will be shown that in application fields, like remote distance sensing, precise alignment measurements, as well as interferometrically-evaluated mechanical strain analysis, the six-port architecture delivers extraordinary measurement results combined with high measurement data update rates for reasonable system costs. This makes the six-port architecture a promising candidate for industrial metrology.

  13. Remote sensing for studying atmospheric aerosols in Malaysia

    Science.gov (United States)

    Kanniah, Kasturi D.; Kamarul Zaman, Nurul A. F.

    2015-10-01

    The aerosol system is Southeast Asia is complex and the high concentrations are due to population growth, rapid urbanization and development of SEA countries. Nevertheless, only a few studies have been carried out especially at large spatial extent and on a continuous basis to study atmospheric aerosols in Malaysia. In this review paper we report the use of remote sensing data to study atmospheric aerosols in Malaysia and document gaps and recommend further studies to bridge the gaps. Satellite data have been used to study the spatial and seasonal patterns of aerosol optical depth (AOD) in Malaysia. Satellite data combined with AERONET data were used to delineate different types and sizes of aerosols and to identify the sources of aerosols in Malaysia. Most of the aerosol studies performed in Malaysia was based on station-based PM10 data that have limited spatial coverage. Thus, satellite data have been used to extrapolate and retrieve PM10 data over large areas by correlating remotely sensed AOD with ground-based PM10. Realising the critical role of aerosols on radiative forcing numerous studies have been conducted worldwide to assess the aerosol radiative forcing (ARF). Such studies are yet to be conducted in Malaysia. Although the only source of aerosol data covering large region in Malaysia is remote sensing, satellite observations are limited by cloud cover, orbital gaps of satellite track, etc. In addition, relatively less understanding is achieved on how the atmospheric aerosol interacts with the regional climate system. These gaps can be bridged by conducting more studies using integrated approach of remote sensing, AERONET and ground based measurements.

  14. Ultra-low power anti-crosstalk collision avoidance light detection and ranging using chaotic pulse position modulation approach

    International Nuclear Information System (INIS)

    Hao Jie; Gong Ma-li; Du Peng-fei; Lu Bao-jie; Zhang Fan; Zhang Hai-tao; Fu Xing

    2016-01-01

    A novel concept of collision avoidance single-photon light detection and ranging (LIDAR) for vehicles has been demonstrated, in which chaotic pulse position modulation is applied on the transmitted laser pulses for robust anti-crosstalk purposes. Besides, single-photon detectors (SPD) and time correlated single photon counting techniques are adapted, to sense the ultra-low power used for the consideration of compact structure and eye safety. Parameters including pulse rate, discrimination threshold, and number of accumulated pulses have been thoroughly analyzed based on the detection requirements, resulting in specified receiver operating characteristics curves. Both simulation and indoor experiments were performed to verify the excellent anti-crosstalk capability of the presented collision avoidance LIDAR despite ultra-low transmitting power. (paper)

  15. Pipeline Structural Damage Detection Using Self-Sensing Technology and PNN-Based Pattern Recognition

    International Nuclear Information System (INIS)

    Lee, Chang Gil; Park, Woong Ki; Park, Seung Hee

    2011-01-01

    In a structure, damage can occur at several scales from micro-cracking to corrosion or loose bolts. This makes the identification of damage difficult with one mode of sensing. Hence, a multi-mode actuated sensing system is proposed based on a self-sensing circuit using a piezoelectric sensor. In the self sensing-based multi-mode actuated sensing, one mode provides a wide frequency-band structural response from the self-sensed impedance measurement and the other mode provides a specific frequency-induced structural wavelet response from the self-sensed guided wave measurement. In this study, an experimental study on the pipeline system is carried out to verify the effectiveness and the robustness of the proposed structural health monitoring approach. Different types of structural damage are artificially inflicted on the pipeline system. To classify the multiple types of structural damage, a supervised learning-based statistical pattern recognition is implemented by composing a two-dimensional space using the damage indices extracted from the impedance and guided wave features. For more systematic damage classification, several control parameters to determine an optimal decision boundary for the supervised learning-based pattern recognition are optimized. Finally, further research issues will be discussed for real-world implementation of the proposed approach

  16. Fusing Multiscale Charts into 3D ENC Systems Based on Underwater Topography and Remote Sensing Image

    Directory of Open Access Journals (Sweden)

    Tao Liu

    2015-01-01

    Full Text Available The purpose of this study is to propose an approach to fuse multiscale charts into three-dimensional (3D electronic navigational chart (ENC systems based on underwater topography and remote sensing image. This is the first time that the fusion of multiscale standard ENCs in the 3D ENC system has been studied. First, a view-dependent visualization technology is presented for the determination of the display condition of a chart. Second, a map sheet processing method is described for dealing with the map sheet splice problem. A process order called “3D order” is designed to adapt to the characteristics of the chart. A map sheet clipping process is described to deal with the overlap between the adjacent map sheets. And our strategy for map sheet splice is proposed. Third, the rendering method for ENC objects in the 3D ENC system is introduced. Fourth, our picking-up method for ENC objects is proposed. Finally, we implement the above methods in our system: automotive intelligent chart (AIC 3D electronic chart display and information systems (ECDIS. And our method can handle the fusion problem well.

  17. Nitrite sensing composite systems based on a core-shell emissive-superamagnetic structure: Construction, characterization and sensing behavior

    Science.gov (United States)

    Yang, Yan; Liu, Liang; Zha, Jianhua; Yuan, Ningyi

    2017-04-01

    Two recyclable nitrite sensing composite samples were designed and constructed through a core-shell structure, with Fe3O4 nanoparticles as core, silica molecular sieve MCM-41 as shell and two rhodamine derivatives as chemosensors, respectively. These samples and their structure were identified with their electron microscopy images, N2 adsorption/desorption isotherms, magnetic response, IR spectra and thermogravimetric analysis. Their nitrite sensing behavior was discussed based on emission intensity quenching, their limit of detection was found as low as 1.2 μM. Further analysis suggested a static sensing mechanism between nitrite and chemosensors through an additive reaction between NO+ and chemosensors. After finishing their nitrite sensing, these composite samples and their emission could be recycled and recovered by sulphamic acid.

  18. New Applications for Detecting Natural Hazards Using Ground and Space-Based GNSS-Derived Ionospheric Measurements

    Science.gov (United States)

    Komjathy, A.; Butala, M.; Verkhoglyadova, O. P.; Wilson, B. D.; Iijima, B.; Akopian, V.; Mannucci, A.

    2012-12-01

    The NASA Jet Propulsion Laboratory (JPL) and University of Southern California (USC) have jointly developed the Global Assimilative Ionospheric Model (GAIM) to monitor space weather, study storm effects, and provide ionospheric calibration for various customers including NASA flight projects. JPL/USC GAIM is a physics-based 3D data assimilation model using 4DVAR and Kalman filter approaches to solve for ion and electron density states and other key ionospheric drivers. The JPL/USC GAIM technologies, now operating in real-time and post-processing modes, can routinely accept as input ground GPS TEC data from 1200+ sites including streaming and hourly GPS stations, occultation links from CHAMP, SAC-C, COSMIC and C/NOFS satellites, UV limb and nadir scans. In the presentation, first we will discuss recent advances in our assimilating ground-based GPS, C/NOFS and COSMIC occultation measurements using our GAIM system characterizing the ionosphere in 3D. We will elaborate on our improved space-based bias estimation techniques to generate high precision calibrated TEC measurements to be assimilated into GAIM. We will discuss the benefits of adding GLONASS measurements to our GIM and GAIM processing technologies. New and upcoming applications and first results will be shown for estimating very high precision TEC perturbations using real-time and post-processed GNSS observations from GEONET and IGS networks. We will demonstrate initial steps on how to integrate this GNSS ionosphere-based technology into a global tsunami warning system. Additional potential applications might include the remote sensing of ionospheric TEC perturbations generated by other natural hazards such as earthquakes and volcanic eruptions and human-made events such as nuclear tests.

  19. Performance analysis of multi-primary color display based on OLEDs/PLEDs

    Science.gov (United States)

    Xiong, Yan; Deng, Fei; Xu, Shan; Gao, Shufang

    2017-09-01

    A multi-primary color display, such as the six-primary color format, is a solution in expanding the color gamut of a full-color flat panel display. The performance of a multi-primary color display based on organic/polymer light-emitting diodes was analyzed in this study using the fitting curves of the characteristics of devices (i.e., current density, voltage, luminance). A white emitter was introduced into a six-primary color format to form a seven-primary color format that contributes to energy saving, and the ratio of power efficiency of a seven-primary color display to that of a six-primary color display would increase from 1.027 to 1.061 by using emitting diodes with different electroluminescent efficiencies. Different color matching schemes of the seven-primary color format display were compared in a uniform color space, and the scheme of the color reproduction did not significantly affect the display performance. Although seven- and six-primary color format displays benefit a full-color display with higher quality, they are less efficient than three-primary (i.e., red (R), green (G), and blue (B), RGB) and four-primary (i.e., RGB+white, RGBW) color format displays. For the seven-primary color formats considered in this study, the advantages of white-primary-added display with efficiently developed light-emitting devices were more evident than the format without a white primary.

  20. Ground- and satellite-based evidence of the biophysical mechanisms behind the greening Sahel.

    Science.gov (United States)

    Brandt, Martin; Mbow, Cheikh; Diouf, Abdoul A; Verger, Aleixandre; Samimi, Cyrus; Fensholt, Rasmus

    2015-04-01

    After a dry period with prolonged droughts in the 1970s and 1980s, recent scientific outcome suggests that the decades of abnormally dry conditions in the Sahel have been reversed by positive anomalies in rainfall. Various remote sensing studies observed a positive trend in vegetation greenness over the last decades which is known as the re-greening of the Sahel. However, little investment has been made in including long-term ground-based data collections to evaluate and better understand the biophysical mechanisms behind these findings. Thus, deductions on a possible increment in biomass remain speculative. Our aim is to bridge these gaps and give specifics on the biophysical background factors of the re-greening Sahel. Therefore, a trend analysis was applied on long time series (1987-2013) of satellite-based vegetation and rainfall data, as well as on ground-observations of leaf biomass of woody species, herb biomass, and woody species abundance in different ecosystems located in the Sahel zone of Senegal. We found that the positive trend observed in satellite vegetation time series (+36%) is caused by an increment of in situ measured biomass (+34%), which is highly controlled by precipitation (+40%). Whereas herb biomass shows large inter-annual fluctuations rather than a clear trend, leaf biomass of woody species has doubled within 27 years (+103%). This increase in woody biomass did not reflect on biodiversity with 11 of 16 woody species declining in abundance over the period. We conclude that the observed greening in the Senegalese Sahel is primarily related to an increasing tree cover that caused satellite-driven vegetation indices to increase with rainfall reversal. © 2014 John Wiley & Sons Ltd.

  1. Correlation of ground-based on topside photometric observations with auroral electron spectra measurements at rocket altitudes

    International Nuclear Information System (INIS)

    Arnoldy, R.L.; Lewis, P.B. Jr.

    1977-01-01

    Spectroscopic measurements of the auroral lines 5577, 4278, and 6300 A made at Fort Yukon, Alaska, are used in the model computations of Rees and Luckey (1974) to predict the energy influx and the characteristic energy of an assumed Maxwellian primary electron spectrum for two auroral displays. Simultaneous with the ground observations, electron detectors aboard a sounding rocket directly measured the primary electron spectrum and energy flux on the field lines which contained the auroral light in the E region observed by the ground photometers (magnetically conjugate in the local sense). For the two auroras studied, the in situ particle measurements show that the model (1) correctly predicts changes in spectral parameters. (2) predicts a precipitated energy flux in good agreement with measured values, and (3) assumes a spectral shape (Maxwellian) not typical of the peaked spectra measured above discrete auroras.One of the rocket flights also carried photometers sensitive to 5577 and 3914 A. Every 0.2 s the photometers sampled the auroral light from the E region magnetically conjugate to the rocket, and they have reaffirmed the very close correlation between emission at 3914 A and that at 5577 A. Finally, by using the measured electron precipitation and current ionospheric models the emissions at 3914, 4278, and 5577 A are calculated. The model computations closely predict the measured light at 3914 and 4278 A. However, the 5577-A emission calculated from dissociative recombination of O 2 + and direct excitation of atomic oxygen using a measured secondary spectrum accounts for only about one third of the observed emission

  2. Adaptive Remote-Sensing Techniques Implementing Swarms of Mobile Agents

    Energy Technology Data Exchange (ETDEWEB)

    Cameron, S.M.; Loubriel, G.M.; Rbinett, R.D. III; Stantz, K.M.; Trahan, M.W.; Wagner, J.S.

    1999-04-01

    This paper focuses on our recent work at Sandia National Laboratories toward engineering a physics-based swarm of mobile vehicles for distributed sensing applications. Our goal is to coordinate a sensor array that optimizes sensor coverage and multivariate signal analysis by implementing artificial intelligence and evolutionary computational techniques. These intelligent control systems integrate both globally operating decision-making systems and locally cooperative information-sharing modes using genetically-trained neural networks. Once trained, neural networks have the ability to enhance real-time operational responses to dynamical environments, such as obstacle avoidance, responding to prevailing wind patterns, and overcoming other natural obscurants or interferences (jammers). The swarm realizes a collective set of sensor neurons with simple properties incorporating interactions based on basic community rules (potential fields) and complex interconnecting functions based on various neural network architectures, Therefore, the swarm is capable of redundant heterogeneous measurements which furnishes an additional degree of robustness and fault tolerance not afforded by conventional systems, while accomplishing such cognitive tasks as generalization, error correction, pattern recognition, and sensor fission. The robotic platforms could be equipped with specialized sensor devices including transmit/receive dipole antennas, chemical or biological sniffers in combination with recognition analysis tools, communication modulators, and laser diodes. Our group has been studying the collective behavior of an autonomous, multi-agent system applied to emerging threat applications. To accomplish such tasks, research in the fields of robotics, sensor technology, and swarms are being conducted within an integrated program. Mission scenarios under consideration include ground penetrating impulse radar (GPR) for detection of under-ground structures, airborne systems, and plume

  3. Principle and Design of a Single-phase Inverter-Based Grounding System for Neutral-to-ground Voltage Compensation in Distribution Networks

    DEFF Research Database (Denmark)

    Wang, Wen; Yan, Lingjie; Zeng, Xiangjun

    2017-01-01

    Neutral-to-ground overvoltage may occur in non-effectively grounded power systems because of the distributed parameters asymmetry and resonance between Petersen coil and distributed capacitances. Thus, the constraint of neutral-to-ground voltage is critical for the safety of distribution networks....... In this paper, an active grounding system based on single-phase inverter and its control parameter design method is proposed to achieve this objective. Relationship between its output current and neutral-to-ground voltage is derived to explain the principle of neutral-to-ground voltage compensation. Then...

  4. Challenges in complementing data from ground-based sensors with satellite-derived products to measure ecological changes in relation to climate – lessons from temperate wetland-upland landscapes

    Science.gov (United States)

    Gallant, Alisa L.; Sadinski, Walter J.; Brown, Jesslyn F.; Senay, Gabriel B.; Roth, Mark F.

    2018-01-01

    Assessing climate-related ecological changes across spatiotemporal scales meaningful to resource managers is challenging because no one method reliably produces essential data at both fine and broad scales. We recently confronted such challenges while integrating data from ground- and satellite-based sensors for an assessment of four wetland-rich study areas in the U.S. Midwest. We examined relations between temperature and precipitation and a set of variables measured on the ground at individual wetlands and another set measured via satellite sensors within surrounding 4 km2 landscape blocks. At the block scale, we used evapotranspiration and vegetation greenness as remotely sensed proxies for water availability and to estimate seasonal photosynthetic activity. We used sensors on the ground to coincidentally measure surface-water availability and amphibian calling activity at individual wetlands within blocks. Responses of landscape blocks generally paralleled changes in conditions measured on the ground, but the latter were more dynamic, and changes in ecological conditions on the ground that were critical for biota were not always apparent in measurements of related parameters in blocks. Here, we evaluate the effectiveness of decisions and assumptions we made in applying the remotely sensed data for the assessment and the value of integrating observations across scales, sensors, and disciplines.

  5. Analysis of Plasmonics Based Fiber Optic Sensing Structures

    Science.gov (United States)

    Moayyed, Hamed

    etching. In this case, an excimer laser was used. Extremely thin fiber tips were obtained, with an ultra-high sensitivity to strain. The other technique employed to fabricate the fiber Bragg gratings was the point-by-point femtosecond laser inscription. In this case, the sensing elements are very stable at high temperatures and can be used to measure strain in harsh conditions. The employment of optical fiber lasers as sensing elements was also considered in this Thesis. Two laser cavities were studied, one based on the ring configuration and the other based on a figure-of-eight configuration. From these works, the quality of the laser emission, namely the signal-to-noise ratio, the reduced full-width at half maximum and the stability should be highlighted. These characteristics allowed the measurement of different physical parameters, such as strain, temperature and torsion. Lastly, the possibility to use microspheres as sensing elements was considered. Using the electric arc of a fusion splicer, it is possible to create microspheres at the tip of an optical fiber. Furthermore, with this technique it is chains of microspheres can be obtained, constituting Mach-Zehnder-type interferometers which are sensitive to physical parameters like strain and temperature. The preliminary results obtained by introducing silica microspheres in a support structure are also presented. In this case, the sensors were subjected to temperature variations. All the experimental work was combined with the respective theoretical considerations. Many questions have been raised with the course of this PhD, and there are still some without a definite answer. Thus, new research paths can be followed, having their basis grounded in the configurations here presented.

  6. Ground based remote sensing and physiological measurements provide novel insights into canopy photosynthetic optimization in arctic shrubs

    Science.gov (United States)

    Magney, T. S.; Griffin, K. L.; Boelman, N.; Eitel, J.; Greaves, H.; Prager, C.; Logan, B.; Oliver, R.; Fortin, L.; Vierling, L. A.

    2014-12-01

    Because changes in vegetation structure and function in the Arctic are rapid and highly dynamic phenomena, efforts to understand the C balance of the tundra require repeatable, objective, and accurate remote sensing methods for estimating aboveground C pools and fluxes over large areas. A key challenge addressing the modelling of aboveground C is to utilize process-level information from fine-scale studies. Utilizing information obtained from high resolution remote sensing systems could help to better understand the C source/sink strength of the tundra, which will in part depend on changes in photosynthesis resulting from the partitioning of photosynthetic machinery within and among deciduous shrub canopies. Terrestrial LiDAR and passive hyperspectral remote sensing measurements offer an effective, repeatable, and scalable method to understand photosynthetic performance and partitioning at the canopy scale previously unexplored in arctic systems. Using a 3-D shrub canopy model derived from LiDAR, we quantified the light regime of leaves within shrub canopies to gain a better understanding of how light interception varies in response to the Arctic's complex radiation regime. This information was then coupled with pigment sampling (i.e., xanthophylls, and Chl a/b) to evaluate the optimization of foliage photosynthetic capacity within shrub canopies due to light availability. In addition, a lab experiment was performed to validate evidence of canopy level optimization via gradients of light intensity and leaf light environment. For this, hyperspectral reflectance (photochemical reflectance index (PRI)), and solar induced fluorescence (SIF)) was collected in conjunction with destructive pigment samples (xanthophylls) and chlorophyll fluorescence measurements in both sunlit and shaded canopy positions.

  7. Modal-pushover-based ground-motion scaling procedure

    Science.gov (United States)

    Kalkan, Erol; Chopra, Anil K.

    2011-01-01

    Earthquake engineering is increasingly using nonlinear response history analysis (RHA) to demonstrate the performance of structures. This rigorous method of analysis requires selection and scaling of ground motions appropriate to design hazard levels. This paper presents a modal-pushover-based scaling (MPS) procedure to scale ground motions for use in a nonlinear RHA of buildings. In the MPS method, the ground motions are scaled to match to a specified tolerance, a target value of the inelastic deformation of the first-mode inelastic single-degree-of-freedom (SDF) system whose properties are determined by the first-mode pushover analysis. Appropriate for first-mode dominated structures, this approach is extended for structures with significant contributions of higher modes by considering elastic deformation of second-mode SDF systems in selecting a subset of the scaled ground motions. Based on results presented for three actual buildings-4, 6, and 13-story-the accuracy and efficiency of the MPS procedure are established and its superiority over the ASCE/SEI 7-05 scaling procedure is demonstrated.

  8. Challenges in paper-based fluorogenic optical sensing with smartphones

    Science.gov (United States)

    Ulep, Tiffany-Heather; Yoon, Jeong-Yeol

    2018-05-01

    Application of optically superior, tunable fluorescent nanotechnologies have long been demonstrated throughout many chemical and biological sensing applications. Combined with microfluidics technologies, i.e. on lab-on-a-chip platforms, such fluorescent nanotechnologies have often enabled extreme sensitivity, sometimes down to single molecule level. Within recent years there has been a peak interest in translating fluorescent nanotechnology onto paper-based platforms for chemical and biological sensing, as a simple, low-cost, disposable alternative to conventional silicone-based microfluidic substrates. On the other hand, smartphone integration as an optical detection system as well as user interface and data processing component has been widely attempted, serving as a gateway to on-board quantitative processing, enhanced mobility, and interconnectivity with informational networks. Smartphone sensing can be integrated to these paper-based fluorogenic assays towards demonstrating extreme sensitivity as well as ease-of-use and low-cost. However, with these emerging technologies there are always technical limitations that must be addressed; for example, paper's autofluorescence that perturbs fluorogenic sensing; smartphone flash's limitations in fluorescent excitation; smartphone camera's limitations in detecting narrow-band fluorescent emission, etc. In this review, physical optical setups, digital enhancement algorithms, and various fluorescent measurement techniques are discussed and pinpointed as areas of opportunities to further improve paper-based fluorogenic optical sensing with smartphones.

  9. Tropospheric and total ozone columns over Paris (France measured using medium-resolution ground-based solar-absorption Fourier-transform infrared spectroscopy

    Directory of Open Access Journals (Sweden)

    C. Viatte

    2011-10-01

    Full Text Available Ground-based Fourier-transform infrared (FTIR solar absorption spectroscopy is a powerful remote sensing technique providing information on the vertical distribution of various atmospheric constituents. This work presents the first evaluation of a mid-resolution ground-based FTIR to measure tropospheric ozone, independently of stratospheric ozone. This is demonstrated using a new atmospheric observatory (named OASIS for "Observations of the Atmosphere by Solar absorption Infrared Spectroscopy", installed in Créteil (France. The capacity of the technique to separate stratospheric and tropospheric ozone is demonstrated. Daily mean tropospheric ozone columns derived from the Infrared Atmospheric Sounding Interferometer (IASI and from OASIS measurements are compared for summer 2009 and a good agreement of −5.6 (±16.1 % is observed. Also, a qualitative comparison between in-situ surface ozone measurements and OASIS data reveals OASIS's capacity to monitor seasonal tropospheric ozone variations, as well as ozone pollution episodes in summer 2009 around Paris. Two extreme pollution events are identified (on the 1 July and 6 August 2009 for which ozone partial columns from OASIS and predictions from a regional air-quality model (CHIMERE are compared following strict criteria of temporal and spatial coincidence. An average bias of 0.2%, a mean square error deviation of 7.6%, and a correlation coefficient of 0.91 is found between CHIMERE and OASIS, demonstrating the potential of a mid-resolution FTIR instrument in ground-based solar absorption geometry for tropospheric ozone monitoring.

  10. Subjective evaluation with FAA criteria: A multidimensional scaling approach. [ground track control management

    Science.gov (United States)

    Kreifeldt, J. G.; Parkin, L.; Wempe, T. E.; Huff, E. F.

    1975-01-01

    Perceived orderliness in the ground tracks of five A/C during their simulated flights was studied. Dynamically developing ground tracks for five A/C from 21 separate runs were reproduced from computer storage and displayed on CRTS to professional pilots and controllers for their evaluations and preferences under several criteria. The ground tracks were developed in 20 seconds as opposed to the 5 minutes of simulated flight using speedup techniques for display. Metric and nonmetric multidimensional scaling techniques are being used to analyze the subjective responses in an effort to: (1) determine the meaningfulness of basing decisions on such complex subjective criteria; (2) compare pilot/controller perceptual spaces; (3) determine the dimensionality of the subjects' perceptual spaces; and thereby (4) determine objective measures suitable for comparing alternative traffic management simulations.

  11. POLARIMETRIC REMOTE SENSING OF ATMOSPHERIC PARTICULATE POLLUTANTS

    Directory of Open Access Journals (Sweden)

    Z. Li

    2018-04-01

    Full Text Available Atmospheric particulate pollutants not only reduce atmospheric visibility, change the energy balance of the troposphere, but also affect human and vegetation health. For monitoring the particulate pollutants, we establish and develop a series of inversion algorithms based on polarimetric remote sensing technology which has unique advantages in dealing with atmospheric particulates. A solution is pointed out to estimate the near surface PM2.5 mass concentrations from full remote sensing measurements including polarimetric, active and infrared remote sensing technologies. It is found that the mean relative error of PM2.5 retrieved by full remote sensing measurements is 35.5 % in the case of October 5th 2013, improved to a certain degree compared to previous studies. A systematic comparison with the ground-based observations further indicates the effectiveness of the inversion algorithm and reliability of results. A new generation of polarized sensors (DPC and PCF, whose observation can support these algorithms, will be onboard GF series satellites and launched by China in the near future.

  12. Yeast surface displaying glucose oxidase as whole-cell biocatalyst: construction, characterization, and its electrochemical glucose sensing application.

    Science.gov (United States)

    Wang, Hongwei; Lang, Qiaolin; Li, Liang; Liang, Bo; Tang, Xiangjiang; Kong, Lingrang; Mascini, Marco; Liu, Aihua

    2013-06-18

    The display of glucose oxidase (GOx) on yeast cell surface using a-agglutinin as an anchor motif was successfully developed. Both the immunochemical analysis and enzymatic assay showed that active GOx was efficiently expressed and translocated on the cell surface. Compared with conventional GOx, the yeast cell surface that displayed GOx (GOx-yeast) demonstrated excellent enzyme properties, such as good stability within a wide pH range (pH 3.5-11.5), good thermostability (retaining over 94.8% enzyme activity at 52 °C and 84.2% enzyme activity at 56 °C), and high d-glucose specificity. In addition, direct electrochemistry was achieved at a GOx-yeast/multiwalled-carbon-nanotube modified electrode, suggesting that the host cell of yeast did not have any adverse effect on the electrocatalytic property of the recombinant GOx. Thus, a novel electrochemical glucose biosensor based on this GOx-yeast was developed. The as-prepared biosensor was linear with the concentration of d-glucose within the range of 0.1-14 mM and a low detection limit of 0.05 mM (signal-to-noise ratio of S/N = 3). Moreover, the as-prepared biosensor is stable, specific, reproducible, simple, and cost-effective, which can be applicable for real sample detection. The proposed strategy to construct robust GOx-yeast may be applied to explore other oxidase-displaying-system-based whole-cell biocatalysts, which can find broad potential application in biosensors, bioenergy, and industrial catalysis.

  13. Simulation of photons from plasmas for the applications to display devices

    Science.gov (United States)

    Lee, Hae June; Yoon, Hyun Jin; Lee, Jae Koo

    2007-07-01

    Numerical modeling of the photon transport of the ultraviolet (UV) and the visible lights are presented for plasma based display devices. The transport of UV lights which undergo resonance trapping by ground state atoms is solved by using the Holstein equation. After the UV lights are transformed to visible lights at the phosphor surfaces, the visible lights experience complicated traces inside the cell and finally are emitted toward the viewing window after having some power loss within the cell. A three-dimensional ray trace of the visible lights is calculated with a radiosity model. These simulations for the photons strengthen plasma discharge modeling for the application to display devices.

  14. Offshore winds mapped from satellite remote sensing

    DEFF Research Database (Denmark)

    Hasager, Charlotte Bay

    2014-01-01

    the uncertainty on the model results on the offshore wind resource, it is necessary to compare model results with observations. Observations from ground-based wind lidar and satellite remote sensing are the two main technologies that can provide new types of offshore wind data at relatively low cost....... The advantages of microwave satellite remote sensing are 1) horizontal spatial coverage, 2) long data archives and 3) high spatial detail both in the coastal zone and of far-field wind farm wake. Passive microwave ocean wind speed data are available since 1987 with up to 6 observations per day with near...

  15. Silicon carbide optics for space and ground based astronomical telescopes

    Science.gov (United States)

    Robichaud, Joseph; Sampath, Deepak; Wainer, Chris; Schwartz, Jay; Peton, Craig; Mix, Steve; Heller, Court

    2012-09-01

    Silicon Carbide (SiC) optical materials are being applied widely for both space based and ground based optical telescopes. The material provides a superior weight to stiffness ratio, which is an important metric for the design and fabrication of lightweight space telescopes. The material also has superior thermal properties with a low coefficient of thermal expansion, and a high thermal conductivity. The thermal properties advantages are important for both space based and ground based systems, which typically need to operate under stressing thermal conditions. The paper will review L-3 Integrated Optical Systems - SSG’s (L-3 SSG) work in developing SiC optics and SiC optical systems for astronomical observing systems. L-3 SSG has been fielding SiC optical components and systems for over 25 years. Space systems described will emphasize the recently launched Long Range Reconnaissance Imager (LORRI) developed for JHU-APL and NASA-GSFC. Review of ground based applications of SiC will include supporting L-3 IOS-Brashear’s current contract to provide the 0.65 meter diameter, aspheric SiC secondary mirror for the Advanced Technology Solar Telescope (ATST).

  16. Comparing and combining terrestrial laser scanning with ground-and UAV-based imaging for national-level assessment of soil erosion

    Science.gov (United States)

    McShane, Gareth; James, Mike R.; Quinton, John; Anderson, Karen; DeBell, Leon; Evans, Martin; Farrow, Luke; Glendell, Miriam; Jones, Lee; Kirkham, Matthew; Lark, Murray; Rawlins, Barry; Rickson, Jane; Quine, Tim; Wetherelt, Andy; Brazier, Richard

    2014-05-01

    3D topographic or surface models are increasingly being utilised for a wide range of applications and are established tools in geomorphological research. In this pilot study 'a cost effective framework for monitoring soil erosion in England and Wales', funded by the UK Department for Environment, Food and Rural Affairs (Defra), we compare methods of collecting topographic measurements via remote sensing for detailed studies of dynamic processes such as erosion and mass movement. The techniques assessed are terrestrial laser scanning (TLS), and unmanned aerial vehicle (UAV) photography and ground-based photography, processed using structure-from-motion (SfM) 3D reconstruction software. The methods will be applied in regions of different land use, including arable and horticultural, upland and semi natural habitats, and grassland, to quantify visible erosion pathways at the site scale. Volumetric estimates of soil loss will be quantified using the digital surface models (DSMs) provided by each technique and a modelled pre-erosion surface. Visible erosion and severity will be independently established through each technique, with their results compared and combined effectiveness assessed. A fixed delta-wing UAV (QuestUAV, http://www.questuav.com/) captures photos from a range of altitudes and angles over the study area, with automated SfM-based processing enabling rapid orthophoto production to support ground-based data acquisition. At sites with suitable scale erosion features, UAV data will also provide a DSM for volume loss measurement. Terrestrial laser scanning will provide detailed, accurate, high density measurements of the ground surface over long (100s m) distances. Ground-based photography is anticipated to be most useful for characterising small and difficult to view features. By using a consumer-grade digital camera and an SfM-based approach (using Agisoft Photoscan version 1.0.0, http://www.agisoft.ru/products/photoscan/), less expertise and fewer control

  17. Connotations of pixel-based scale effect in remote sensing and the modified fractal-based analysis method

    Science.gov (United States)

    Feng, Guixiang; Ming, Dongping; Wang, Min; Yang, Jianyu

    2017-06-01

    Scale problems are a major source of concern in the field of remote sensing. Since the remote sensing is a complex technology system, there is a lack of enough cognition on the connotation of scale and scale effect in remote sensing. Thus, this paper first introduces the connotations of pixel-based scale and summarizes the general understanding of pixel-based scale effect. Pixel-based scale effect analysis is essentially important for choosing the appropriate remote sensing data and the proper processing parameters. Fractal dimension is a useful measurement to analysis pixel-based scale. However in traditional fractal dimension calculation, the impact of spatial resolution is not considered, which leads that the scale effect change with spatial resolution can't be clearly reflected. Therefore, this paper proposes to use spatial resolution as the modified scale parameter of two fractal methods to further analyze the pixel-based scale effect. To verify the results of two modified methods (MFBM (Modified Windowed Fractal Brownian Motion Based on the Surface Area) and MDBM (Modified Windowed Double Blanket Method)); the existing scale effect analysis method (information entropy method) is used to evaluate. And six sub-regions of building areas and farmland areas were cut out from QuickBird images to be used as the experimental data. The results of the experiment show that both the fractal dimension and information entropy present the same trend with the decrease of spatial resolution, and some inflection points appear at the same feature scales. Further analysis shows that these feature scales (corresponding to the inflection points) are related to the actual sizes of the geo-object, which results in fewer mixed pixels in the image, and these inflection points are significantly indicative of the observed features. Therefore, the experiment results indicate that the modified fractal methods are effective to reflect the pixel-based scale effect existing in remote sensing

  18. PhotoSpec - Ground-based Remote Sensing of Solar-Induced Chlorophyll Fluorescence: First Results

    Science.gov (United States)

    Grossmann, K.; Magney, T. S.; Frankenberg, C.; Seibt, U.; Pivovaroff, A. L.; Hurlock, S. C.; Stutz, J.

    2016-12-01

    Solar-Induced Chlorophyll Fluorescence (SIF) emitted from vegetation can be used as a proxy for photosynthetic activity and is observable on a global scale from space. However, many issues on a leaf-to-canopy scale remain poorly understood, such as influences on the SIF signal from environmental conditions, water stress, or radiation. We have developed a novel ground-based spectrometer system for measuring SIF from natural ecosystems. The instrumental set-up, requirements, and measurement technique are based on decades of experience using Differential Optical Absorption Spectroscopy (DOAS), an established method to measure atmospheric trace gases. The instrument consists of three thermally stabilized commercial spectrometers that are linked to a 2D scanning telescope unit via optical fiber bundles, and also includes a commercial photosynthetic active radiation (PAR) sensor. The spectrometers cover a SIF retrieval wavelength range at high spectral resolution (670 - 780 nm, 0.1 nm FWHM), and also provide moderate resolution spectra (400 - 800 nm, 1.5 nm FWHM) to retrieve vegetation indices and the photochemical reflectance index (PRI). We report on results of the first continuous field measurements of this novel system at Stunt Ranch Santa Monica Mountains UC Reserve, where the PhotoSpec instrument was monitoring SIF of four native Californian shrubland species with different adaptations to seasonal summer drought. We report on the correlation with CO2 fluxes over both the growing season and the hot summer period in 2016. We also show detailed measurements of the diurnal cycle of the SIF signal of single broad leaves, as well as dark-light transitions, under controlled experimental conditions. In addition to demonstrating the instrumental set-up, retrieval algorithm, and instrument performance, our results illustrate that SIF measurements at the leaf to ecosystem scale are needed to understand and interpret the SIF signals retrieved at larger scales.

  19. Mechanical Stability of Flexible Graphene-Based Displays.

    Science.gov (United States)

    Anagnostopoulos, George; Pappas, Panagiotis-Nektarios; Li, Zheling; Kinloch, Ian A; Young, Robert J; Novoselov, Kostya S; Lu, Ching Yu; Pugno, Nicola; Parthenios, John; Galiotis, Costas; Papagelis, Konstantinos

    2016-08-31

    The mechanical behavior of a prototype touch panel display, which consists of two layers of CVD graphene embedded into PET films, is investigated in tension and under contact-stress dynamic loading. In both cases, laser Raman spectroscopy was employed to assess the stress transfer efficiency of the embedded graphene layers. The tensile behavior was found to be governed by the "island-like" microstructure of the CVD graphene, and the stress transfer efficiency was dependent on the size of graphene "islands" but also on the yielding behavior of PET at relatively high strains. Finally, the fatigue tests, which simulate real operation conditions, showed that the maximum temperature gradient developed at the point of "finger" contact after 80 000 cycles does not exceed the glass transition temperature of the PET matrix. The effect of these results on future product development and the design of new graphene-based displays are discussed.

  20. Scaling earthquake ground motions for performance-based assessment of buildings

    Science.gov (United States)

    Huang, Y.-N.; Whittaker, A.S.; Luco, N.; Hamburger, R.O.

    2011-01-01

    The impact of alternate ground-motion scaling procedures on the distribution of displacement responses in simplified structural systems is investigated. Recommendations are provided for selecting and scaling ground motions for performance-based assessment of buildings. Four scaling methods are studied, namely, (1)geometric-mean scaling of pairs of ground motions, (2)spectrum matching of ground motions, (3)first-mode-period scaling to a target spectral acceleration, and (4)scaling of ground motions per the distribution of spectral demands. Data were developed by nonlinear response-history analysis of a large family of nonlinear single degree-of-freedom (SDOF) oscillators that could represent fixed-base and base-isolated structures. The advantages and disadvantages of each scaling method are discussed. The relationship between spectral shape and a ground-motion randomness parameter, is presented. A scaling procedure that explicitly considers spectral shape is proposed. ?? 2011 American Society of Civil Engineers.

  1. Information operator approach applied to the retrieval of vertical distributions of atmospheric constituents from ground-based FTIR measurements

    Science.gov (United States)

    Senten, Cindy; de Mazière, Martine; Vanhaelewyn, Gauthier; Vigouroux, Corinne; Delmas, Robert

    2010-05-01

    The retrieval of information about the vertical distribution of an atmospheric absorber from high spectral resolution ground-based Fourier Transform infrared (FTIR) solar absorption spectra is an important issue in remote sensing. A frequently used technique at present is the optimal estimation method. This work introduces the application of an alternative method, namely the information operator approach (Doicu et al., 2007; Hoogen et al., 1999), for extracting the available information from such FTIR measurements. This approach has been implemented within the well-known retrieval code SFIT2, by adapting the optimal estimation method such as to take into account only the significant contributions to the solution. In particular, we demonstrate the feasibility of the method when applied to ground-based FTIR spectra taken at the southern (sub)tropical site Ile de La Réunion (21° S, 55° E) in 2007. A thorough comparison has been made between the retrieval results obtained with the original optimal estimation method and the ones obtained with the information operator approach, regarding profile and column stability, information content and corresponding full error budget evaluation. This has been done for the target species ozone (O3), methane (CH4), nitrous oxide (N2O), and carbon monoxide (CO). It is shown that the information operator approach performs well and is capable of achieving the same accuracy as optimal estimation, with a gain of stability and with the additional advantage of being less sensitive to the choice of a priori information as well as to the actual signal-to-noise ratio. Keywords: ground-based FTIR, solar absorption spectra, greenhouse gases, information operator approach References Doicu, A., Hilgers, S., von Bargen, A., Rozanov, A., Eichmann, K.-U., von Savigny, C., and Burrows, J.P.: Information operator approach and iterative regularization methods for atmospheric remote sensing, J. Quant. Spectrosc. Radiat. Transfer, 103, 340-350, 2007

  2. Analysis of polarization characteristics of plant canopies using ground-based remote sensing measurements

    International Nuclear Information System (INIS)

    Sid’ko, A.F.; Botvich, I.Yu.; Pisman, T.I.; Shevyrnogov, A.P.

    2014-01-01

    The paper presents results and analysis of a study on polarized characteristics of the reflectance factor of different plant canopies under field conditions, using optical remote sensing techniques. Polarization characteristics were recorded from the elevated work platform at heights of 10–18 m in June and July. Measurements were performed using a double-beam spectrophotometer with a polarized light filter attachment, within the spectral range from 400 to 820 nm. The viewing zenith angle was below 20 degree. Birch (Betila pubescens), pine (Pinus sylvestris L.), wheat (Triticum acstivum) [L.] crops, corn (Zea mays L. ssp. mays) crops, and various grass canopies were used in this study. The following polarization characteristics were studied: the reflectance factor of the canopy with the polarizer adjusted to transmit the maximum and minimum amounts of light (R max and R min ), polarized component of the reflectance factor (R q ), and the degree of polarization (P). Wheat, corn, and grass canopies have higher R max and R min values than forest plants. The R q and P values are higher for the birch than for the pine within the wavelength range between 430 and 740 nm. The study shows that polarization characteristics of plant canopies may be used as an effective means of decoding remote sensing data. - Highlights: • The reflection and polarization properties of plant were studied. • The compiled electronic database of the spectrophotometric information of plant. • Polarization characteristics are a source of useful data on the state of plants

  3. OMI and Ground-Based In-Situ Tropospheric Nitrogen Dioxide Observations over Several Important European Cities during 2005–2014

    Directory of Open Access Journals (Sweden)

    Spiru Paraschiv

    2017-11-01

    Full Text Available In this work we present the evolution of tropospheric nitrogen dioxide (NO2 content over several important European cities during 2005–2014 using space observations and ground-based in-situ measurements. The NO2 content was derived using the daily observations provided by the Ozone Monitoring Instrument (OMI, while the NO2 volume mixing ratio measurements were obtained from the European Environment Agency (EEA air quality monitoring stations database. The European cities selected are: Athens (37.98° N, 23.72° E, Berlin (52.51° N, 13.41° E, Bucharest (44.43° N, 26.10° E, Madrid (40.38° N, 3.71° W, Lisbon (38.71° N, 9.13° W, Paris (48.85° N, 2.35° E, Rome (41.9° N, 12.50° E, and Rotterdam (51.91° N, 4.46° E. We show that OMI NO2 tropospheric column data can be used to assess the evolution of NO2 over important European cities. According to the statistical analysis, using the seasonal variation, we found good correlations (R > 0.50 between OMI and ground-based in-situ observations for all of the cities presented in this work. Highest correlation coefficients (R > 0.80 between ground-based monitoring stations and OMI observations were calculated for the cities of Berlin, Madrid, and Rome. Both types of observations, in-situ and remote sensing, show an NO2 negative trend for all of locations presented in this study.

  4. Hanford Ground-Water Data Base management guide

    International Nuclear Information System (INIS)

    Rieger, J.T.; Mitchell, P.J.; Muffett, D.M.; Fruland, R.M.; Moore, S.B.; Marshall, S.M.

    1990-02-01

    This guide describes the Hanford Ground-Water Data Base (HGWDB), a computerized data base used to store hydraulic head, sample analytical, temperature, geologic, and well-structure information for ground-water monitoring wells on the Hanford Site. These data are stored for the purpose of data retrieval for report generation and also for historical purposes. This guide is intended as an aid to the data base manager and the various staff authorized to enter and verify data, maintain the data base, and maintain the supporting software. This guide focuses on the structure of the HGWDB, providing a fairly detailed description of the programs, files, and parameters. Data-retrieval instructions for the general user of the HGWDB will be found in the HGWDB User's Manual. 6 figs

  5. The Impact of Suggestive Maneuver Guidance on UAS Pilots Performing the Detect and Avoid Function

    Science.gov (United States)

    Rorie, Conrad; Fern, Lisa; Shively, Jay

    2016-01-01

    This presentation discusses the results of a recent UAS Integration into the NAS human-in-the-loop simulation. In the study, 16 active UAS pilots flew a UAS through civil airspace and were tasked with maintaining well clear from other aircraft in the area. Pilots performed the task with four different detect and avoid (DAA) traffic displays, each of which varied in the form of guidance it provided to pilots The present findings focus on how the different displays impacted pilots' measured response to scripted conflicts with their aircraft. Measured response is made up of several components, each of which help inform our understanding of the pilots' role in the overall detect and avoid task.

  6. Unmanned Aerial Systems and Spectroscopy for Remote Sensing Applications in Archaeology

    Science.gov (United States)

    Themistocleous, K.; Agapiou, A.; Cuca, B.; Hadjimitsis, D. G.

    2015-04-01

    Remote sensing has open up new dimensions in archaeological research. Although there has been significant progress in increasing the resolution of space/aerial sensors and image processing, the detection of the crop (and soil marks) formations, which relate to buried archaeological remains, are difficult to detect since these marks may not be visible in the images if observed over different period or at different spatial/spectral resolution. In order to support the improvement of earth observation remote sensing technologies specifically targeting archaeological research, a better understanding of the crop/soil marks formation needs to be studied in detail. In this paper the contribution of both Unmanned Aerial Systems as well ground spectroradiometers is discussed in a variety of examples applied in the eastern Mediterranean region (Cyprus and Greece) as well in Central Europe (Hungary). In- situ spectroradiometric campaigns can be applied for the removal of atmospheric impact to simultaneous satellite overpass images. In addition, as shown in this paper, the systematic collection of ground truth data prior to the satellite/aerial acquisition can be used to detect the optimum temporal and spectral resolution for the detection of stress vegetation related to buried archaeological remains. Moreover, phenological studies of the crops from the area of interest can be simulated to the potential sensors based on their Relative Response Filters and therefore prepare better the satellite-aerial campaigns. Ground data and the use of Unmanned Aerial Systems (UAS) can provide an increased insight for studying the formation of crop and soil marks. New algorithms such as vegetation indices and linear orthogonal equations for the enhancement of crop marks can be developed based on the specific spectral characteristics of the area. As well, UAS can be used for remote sensing applications in order to document, survey and model cultural heritage and archaeological sites.

  7. Leds used as spectral selective light detectors in remote sensing techniques

    International Nuclear Information System (INIS)

    Weber, C; Tocho, J O; Rodriguez, E J; Acciaresi, H A

    2011-01-01

    Remote sensing has been commonly considered as an effective technique in developing precision agriculture tools. Ground based and satellite spectral sensors have wide uses to retrieve remotely quantitative biophysical and biochemical characteristics of vegetation canopies as well as vegetation ground cover. Usually in-field remote sensing technologies use either a combination of interferential filters and photodiodes or different compact spectrometers to separate the spectral regions of interest. In this paper we present a new development of a sensor with LEDs used as spectrally selective photodetectors. Its performance was compared with a photodiode-filter sensor used in agronomic applications. Subsequent measurements of weed cover degree were performed and compared with other methodologies. Results show that the new LEDs based sensor has similar features that conventional ones to determining the weed soil cover degree; while LEDs based sensor has comparative advantages related its very low manufacturing cost and its robustness compatible with agricultural field applications.

  8. Research on Chinese characters display of airborne MFD based on GL studio

    Science.gov (United States)

    Wang, Zhile; Dong, Junyu; Hu, Wenting; Cui, Yipeng

    2018-04-01

    GL Studio cannot display Chinese characters during developing the airborne MFD, this paper propose a method of establishing a Chinese character font with GB2312 encoding, establish the font table and the display unit of Chinese characters based on GL Studio. Abstract the storage and display data model of Chinese characters, parse the GB encoding of the corresponding Chinese characters that MFD received, find the coordinates of the Chinese characters in the font table, establish the dynamic control model and the dynamic display model of Chinese characters based on the display unit of Chinese characters. In GL Studio and VC ++.NET environment, this model has been successfully applied to develop the airborne MFD in a variety of mission simulators. This method has successfully solved the problem that GL Studio software cannot develop MFD software of Chinese domestic aircraft and can also be used for other professional airborne MFD development tools such as IDATA. It has been proved by experiments that this is a fast effective scalable and reconfigurable method of developing both actual equipment and simulators.

  9. EDOVE: Energy and Depth Variance-Based Opportunistic Void Avoidance Scheme for Underwater Acoustic Sensor Networks.

    Science.gov (United States)

    Bouk, Safdar Hussain; Ahmed, Syed Hassan; Park, Kyung-Joon; Eun, Yongsoon

    2017-09-26

    Underwater Acoustic Sensor Network (UASN) comes with intrinsic constraints because it is deployed in the aquatic environment and uses the acoustic signals to communicate. The examples of those constraints are long propagation delay, very limited bandwidth, high energy cost for transmission, very high signal attenuation, costly deployment and battery replacement, and so forth. Therefore, the routing schemes for UASN must take into account those characteristics to achieve energy fairness, avoid energy holes, and improve the network lifetime. The depth based forwarding schemes in literature use node's depth information to forward data towards the sink. They minimize the data packet duplication by employing the holding time strategy. However, to avoid void holes in the network, they use two hop node proximity information. In this paper, we propose the Energy and Depth variance-based Opportunistic Void avoidance (EDOVE) scheme to gain energy balancing and void avoidance in the network. EDOVE considers not only the depth parameter, but also the normalized residual energy of the one-hop nodes and the normalized depth variance of the second hop neighbors. Hence, it avoids the void regions as well as balances the network energy and increases the network lifetime. The simulation results show that the EDOVE gains more than 15 % packet delivery ratio, propagates 50 % less copies of data packet, consumes less energy, and has more lifetime than the state of the art forwarding schemes.

  10. The human factors of CRT displays for nuclear power plant control

    International Nuclear Information System (INIS)

    Danchak, M.M.

    1984-01-01

    This chapter attempts to show how the Cathode Ray Tube (CRT) can be used to effectively present information to the operator rather than just data. The capabilities of the human as a sensing and information processing subsystem are discussed with CRT displays in mind. The display system is described in terms of its hardware and functioning. The interface between the two is examined by providing substantive guidelines for the effective design of CRT displays for nuclear power plant control. Alphanumeric displays, graphic displays, and representational displays are treated. The design of CRT displays for nuclear power plant control requires an extensive knowledge of cognitive psychology, computer display systems and the process being controlled

  11. Intelligent Chiral Sensing Based on Supramolecular and Interfacial Concepts

    Directory of Open Access Journals (Sweden)

    Hironori Izawa

    2010-07-01

    Full Text Available Of the known intelligently-operating systems, the majority can undoubtedly be classed as being of biological origin. One of the notable differences between biological and artificial systems is the important fact that biological materials consist mostly of chiral molecules. While most biochemical processes routinely discriminate chiral molecules, differentiation between chiral molecules in artificial systems is currently one of the challenging subjects in the field of molecular recognition. Therefore, one of the important challenges for intelligent man-made sensors is to prepare a sensing system that can discriminate chiral molecules. Because intermolecular interactions and detection at surfaces are respectively parts of supramolecular chemistry and interfacial science, chiral sensing based on supramolecular and interfacial concepts is a significant topic. In this review, we briefly summarize recent advances in these fields, including supramolecular hosts for color detection on chiral sensing, indicator-displacement assays, kinetic resolution in supramolecular reactions with analyses by mass spectrometry, use of chiral shape-defined polymers, such as dynamic helical polymers, molecular imprinting, thin films on surfaces of devices such as QCM, functional electrodes, FET, and SPR, the combined technique of magnetic resonance imaging and immunoassay, and chiral detection using scanning tunneling microscopy and cantilever technology. In addition, we will discuss novel concepts in recent research including the use of achiral reagents for chiral sensing with NMR, and mechanical control of chiral sensing. The importance of integration of chiral sensing systems with rapidly developing nanotechnology and nanomaterials is also emphasized.

  12. Symbiotic Sensing for Energy-Intensive Tasks in Large-Scale Mobile Sensing Applications.

    Science.gov (United States)

    Le, Duc V; Nguyen, Thuong; Scholten, Hans; Havinga, Paul J M

    2017-11-29

    Energy consumption is a critical performance and user experience metric when developing mobile sensing applications, especially with the significantly growing number of sensing applications in recent years. As proposed a decade ago when mobile applications were still not popular and most mobile operating systems were single-tasking, conventional sensing paradigms such as opportunistic sensing and participatory sensing do not explore the relationship among concurrent applications for energy-intensive tasks. In this paper, inspired by social relationships among living creatures in nature, we propose a symbiotic sensing paradigm that can conserve energy, while maintaining equivalent performance to existing paradigms. The key idea is that sensing applications should cooperatively perform common tasks to avoid acquiring the same resources multiple times. By doing so, this sensing paradigm executes sensing tasks with very little extra resource consumption and, consequently, extends battery life. To evaluate and compare the symbiotic sensing paradigm with the existing ones, we develop mathematical models in terms of the completion probability and estimated energy consumption. The quantitative evaluation results using various parameters obtained from real datasets indicate that symbiotic sensing performs better than opportunistic sensing and participatory sensing in large-scale sensing applications, such as road condition monitoring, air pollution monitoring, and city noise monitoring.

  13. Symbiotic Sensing for Energy-Intensive Tasks in Large-Scale Mobile Sensing Applications

    Science.gov (United States)

    Scholten, Hans; Havinga, Paul J. M.

    2017-01-01

    Energy consumption is a critical performance and user experience metric when developing mobile sensing applications, especially with the significantly growing number of sensing applications in recent years. As proposed a decade ago when mobile applications were still not popular and most mobile operating systems were single-tasking, conventional sensing paradigms such as opportunistic sensing and participatory sensing do not explore the relationship among concurrent applications for energy-intensive tasks. In this paper, inspired by social relationships among living creatures in nature, we propose a symbiotic sensing paradigm that can conserve energy, while maintaining equivalent performance to existing paradigms. The key idea is that sensing applications should cooperatively perform common tasks to avoid acquiring the same resources multiple times. By doing so, this sensing paradigm executes sensing tasks with very little extra resource consumption and, consequently, extends battery life. To evaluate and compare the symbiotic sensing paradigm with the existing ones, we develop mathematical models in terms of the completion probability and estimated energy consumption. The quantitative evaluation results using various parameters obtained from real datasets indicate that symbiotic sensing performs better than opportunistic sensing and participatory sensing in large-scale sensing applications, such as road condition monitoring, air pollution monitoring, and city noise monitoring. PMID:29186037

  14. Symbiotic Sensing for Energy-Intensive Tasks in Large-Scale Mobile Sensing Applications

    Directory of Open Access Journals (Sweden)

    Duc V. Le

    2017-11-01

    Full Text Available Energy consumption is a critical performance and user experience metric when developing mobile sensing applications, especially with the significantly growing number of sensing applications in recent years. As proposed a decade ago when mobile applications were still not popular and most mobile operating systems were single-tasking, conventional sensing paradigms such as opportunistic sensing and participatory sensing do not explore the relationship among concurrent applications for energy-intensive tasks. In this paper, inspired by social relationships among living creatures in nature, we propose a symbiotic sensing paradigm that can conserve energy, while maintaining equivalent performance to existing paradigms. The key idea is that sensing applications should cooperatively perform common tasks to avoid acquiring the same resources multiple times. By doing so, this sensing paradigm executes sensing tasks with very little extra resource consumption and, consequently, extends battery life. To evaluate and compare the symbiotic sensing paradigm with the existing ones, we develop mathematical models in terms of the completion probability and estimated energy consumption. The quantitative evaluation results using various parameters obtained from real datasets indicate that symbiotic sensing performs better than opportunistic sensing and participatory sensing in large-scale sensing applications, such as road condition monitoring, air pollution monitoring, and city noise monitoring.

  15. 3D display system using monocular multiview displays

    Science.gov (United States)

    Sakamoto, Kunio; Saruta, Kazuki; Takeda, Kazutoki

    2002-05-01

    A 3D head mounted display (HMD) system is useful for constructing a virtual space. The authors have researched the virtual-reality systems connected with computer networks for real-time remote control and developed a low-priced real-time 3D display for building these systems. We developed a 3D HMD system using monocular multi-view displays. The 3D displaying technique of this monocular multi-view display is based on the concept of the super multi-view proposed by Kajiki at TAO (Telecommunications Advancement Organization of Japan) in 1996. Our 3D HMD has two monocular multi-view displays (used as a visual display unit) in order to display a picture to the left eye and the right eye. The left and right images are a pair of stereoscopic images for the left and right eyes, then stereoscopic 3D images are observed.

  16. Gadolinium(III) ion selective sensor using a new synthesized Schiff's base as a sensing material

    International Nuclear Information System (INIS)

    Zamani, Hassan Ali; Mohammadhosseini, Majid; Haji-Mohammadrezazadeh, Saeed; Faridbod, Farnoush; Ganjali, Mohammad Reza; Meghdadi, Soraia; Davoodnia, Abolghasem

    2012-01-01

    According to a solution study which showed a selective complexation between N,N′-bis(methylsalicylidene)-2-aminobenzylamine (MSAB) and gadolinium ions, MSAB was used as a sensing element in construction of a gadolinium(III) ion selective electrode. Acetophenon (AP) was used as solvent mediator and sodium tetraphenyl borate (NaTPB) as an anion excluder. The electrode showed a good selectivity towards Gd(III) ions over a wide variety of cations tested. The constructed sensor displayed a Nernstian behavior (19.7 ± 0.3 mV/decade) in the concentration range of 1.0 × 10 −6 to 1.0 × 10 −2 mol L −1 with detection limit of 5.0 × 10 −7 mol L −1 and a short response time ( 3+ –PVC membrane sensor based on an ion carrier as sensing material is introduced. ► This technique is very simple and it's not necessary to use sophisticated equipment. ► This sensor shows good selectivity against other metal ions.

  17. Blind compressed sensing image reconstruction based on alternating direction method

    Science.gov (United States)

    Liu, Qinan; Guo, Shuxu

    2018-04-01

    In order to solve the problem of how to reconstruct the original image under the condition of unknown sparse basis, this paper proposes an image reconstruction method based on blind compressed sensing model. In this model, the image signal is regarded as the product of a sparse coefficient matrix and a dictionary matrix. Based on the existing blind compressed sensing theory, the optimal solution is solved by the alternative minimization method. The proposed method solves the problem that the sparse basis in compressed sensing is difficult to represent, which restrains the noise and improves the quality of reconstructed image. This method ensures that the blind compressed sensing theory has a unique solution and can recover the reconstructed original image signal from a complex environment with a stronger self-adaptability. The experimental results show that the image reconstruction algorithm based on blind compressed sensing proposed in this paper can recover high quality image signals under the condition of under-sampling.

  18. Hazard avoidance via descent images for safe landing

    Science.gov (United States)

    Yan, Ruicheng; Cao, Zhiguo; Zhu, Lei; Fang, Zhiwen

    2013-10-01

    In planetary or lunar landing missions, hazard avoidance is critical for landing safety. Therefore, it is very important to correctly detect hazards and effectively find a safe landing area during the last stage of descent. In this paper, we propose a passive sensing based HDA (hazard detection and avoidance) approach via descent images to lower the landing risk. In hazard detection stage, a statistical probability model on the basis of the hazard similarity is adopted to evaluate the image and detect hazardous areas, so that a binary hazard image can be generated. Afterwards, a safety coefficient, which jointly utilized the proportion of hazards in the local region and the inside hazard distribution, is proposed to find potential regions with less hazards in the binary hazard image. By using the safety coefficient in a coarse-to-fine procedure and combining it with the local ISD (intensity standard deviation) measure, the safe landing area is determined. The algorithm is evaluated and verified with many simulated descent downward looking images rendered from lunar orbital satellite images.

  19. Aerosol and Cloud Properties during the Cloud Cheju ABC Plume -Asian Monsoon Experiment (CAPMEX) 2008: Linking between Ground-based and UAV Measurements

    Science.gov (United States)

    Kim, S.; Yoon, S.; Venkata Ramana, M.; Ramanathan, V.; Nguyen, H.; Park, S.; Kim, M.

    2009-12-01

    Cheju Atmospheric Brown Cloud (ABC) Plume-Monsoon Experiment (CAPMEX), comprehsensive ground-based measurements and a series of data-gathering flights by specially equipped autonomous unmanned aerial vehicles (AUAVs) for aerosol and cloud, had conducted at Jeju (formerly, Cheju), South Korea during August-September 2008, to improve our understanding of how the reduction of anthropogenic emissions in China (so-called “great shutdown” ) during and after the Summer Beijing Olympic Games 2008 effcts on the air quliaty and radiation budgets and how atmospheric brown clouds (ABCs) influences solar radiation budget off Asian continent. Large numbers of in-situ and remote sensing instruments at the Gosan ABC observatory and miniaturized instruments on the aircraft measure a range of properties such as the quantity of soot, size-segregated aerosol particle numbers, total particle numbers, size-segregated cloud droplet numbers (only AUAV), aerosol scattering properties (only ground), aerosol vertical distribution, column-integrated aerosol properties, and meteorological variables. By integrating ground-level and high-elevation AUAV measurements with NASA-satellite observations (e.g., MODIS, CALIPSO), we investigate the long range transport of aerosols, the impact of ABCs on clouds, and the role of biogenic and anthropogenic aerosols on cloud condensation nuclei (CCN). In this talk, we will present the results from CAPMEX focusing on: (1) the characteristics of aerosol optical, physical and chemical properties at Gosan observatory, (2) aerosol solar heating calculated from the ground-based micro-pulse lidar and AERONET sun/sky radiometer synergy, and comparison with direct measurements from UAV, and (3) aerosol-cloud interactions in conjunction with measurements by satellites and Gosan observatory.

  20. Conflict resolution maneuvers during near miss encounters with cockpit traffic displays

    Science.gov (United States)

    Palmer, E.

    1983-01-01

    The benefits and liabilities associated with pilots' use of a cockpit traffic display to assess the threat posed by air traffic and to make small maneuvers to avoid situations which would result in collision avoidance advisories are experimentally studied. The crew's task was to fly a simulated wide-body aircraft along a straight course at constant altitude while intruder aircraft appeared on a variety of converging trajectories. The main experimental variables were the amount and quality of the information displayed on the intruder aircraft's estimated future position. Pilots were to maintain a horizontal separation of at least 1.5 nautical miles or a vertical separation of 500 ft, so that collision avoidance advisories would not be triggered. The results show that pilots could usually maneuver to provide the specified separation but often made course deviations greater than 1.5 nm or 500 ft.

  1. Preliminary PANSAT ground station software design and use of an expert system to analyze telemetry

    Science.gov (United States)

    Lawrence, Gregory W.

    1994-03-01

    The Petite Amateur Navy Satellite (PANSAT) is a communications satellite designed to be used by civilian amateur radio operators. A master ground station is being built at the Naval Postgraduate School. This computer system performs satellite commands, displays telemetry, trouble-shoots problems, and passes messages. The system also controls an open loop tracking antenna. This paper concentrates on the telemetry display, decoding, and interpretation through artificial intelligence (AI). The telemetry is displayed in an easily interpretable format, so that any user can understand the current health of the satellite and be cued as to any problems and possible solutions. Only the master ground station has the ability to receive all telemetry and send commands to the spacecraft; civilian ham users do not have access to this information. The telemetry data is decommutated and analyzed before it is displayed to the user, so that the raw data will not have to be interpreted by ground users. The analysis will use CLIPS imbedded in the code, and derive its inputs from telemetry decommutation. The program is an expert system using a forward chaining set of rules based on the expected operation and parameters of the satellite. By building the rules during the construction and design of the satellite, the telemetry can be well understood and interpreted after the satellite is launched and the designers may no longer be available to provide input to the problem.

  2. Performance Based Criteria for Ship Collision and Grounding

    DEFF Research Database (Denmark)

    Pedersen, Preben Terndrup

    2009-01-01

    The paper outlines a probabilistic procedure whereby the maritime industry can develop performance based rules to reduce the risk associated with human, environmental and economic costs of collision and grounding events and identify the most economic risk control options associated with prevention...

  3. METHOD OF GROUP OBJECTS FORMING FOR SPACE-BASED REMOTE SENSING OF THE EARTH

    Directory of Open Access Journals (Sweden)

    A. N. Grigoriev

    2015-07-01

    Full Text Available Subject of Research. Research findings of the specific application of space-based optical-electronic and radar means for the Earth remote sensing are considered. The subject matter of the study is the current planning of objects survey on the underlying surface in order to increase the effectiveness of sensing system due to the rational use of its resources. Method. New concept of a group object, stochastic swath and stochastic length of the route is introduced. The overview of models for single, group objects and their parameters is given. The criterion for the existence of the group object based on two single objects is formulated. The method for group objects formation while current survey planning has been developed and its description is presented. The method comprises several processing stages for data about objects with the calculation of new parameters, the stochastic characteristics of space means and validates the spatial size of the object value of the stochastic swath and stochastic length of the route. The strict mathematical description of techniques for model creation of a group object based on data about a single object and onboard special complex facilities in difficult conditions of registration of spatial data is given. Main Results. The developed method is implemented on the basis of modern geographic information system in the form of a software tool layout with advanced tools of processing and analysis of spatial data in vector format. Experimental studies of the forming method for the group of objects were carried out on a different real object environment using the parameters of modern national systems of the Earth remote sensing detailed observation Canopus-B and Resurs-P. Practical Relevance. The proposed models and method are focused on practical implementation using vector spatial data models and modern geoinformation technologies. Practical value lies in the reduction in the amount of consumable resources by means of

  4. Empirical Determination of Efficient Sensing Frequencies for Magnetometer-Based Continuous Human Contact Monitoring

    Directory of Open Access Journals (Sweden)

    Seungho Kuk

    2018-04-01

    Full Text Available The high linear correlation between the smartphone magnetometer readings in close proximity can be exploited for physical human contact detection, which could be useful for such applications as infectious disease contact tracing or social behavior monitoring. Alternative approaches using other capabilities in smartphones have aspects that do not fit well with the human contact detection. Using Wi-Fi or cellular fingerprints have larger localization errors than close human contact distances. Bluetooth beacons could reveal the identity of the transmitter, threatening the privacy of the user. Also, using sensors such as GPS does not work for indoor contacts. However, the magnetometer correlation check works best in human contact distances that matter in infectious disease transmissions or social interactions. The omni-present geomagnetism makes it work both indoors and outdoors, and the measured magnetometer values do not easily reveal the identity and the location of the smartphone. One issue with the magnetometer-based contact detection, however, is the energy consumption. Since the contacts can take place anytime, the magnetometer sensing and recording should be running continuously. Therefore, how we address the energy requirement for the extended and continuous operation can decide the viability of the whole idea. However, then, we note that almost all existing magnetometer-based applications such as indoor location and navigation have used high sensing frequencies, ranging from 10 Hz to 200 Hz. At these frequencies, we measure that the time to complete battery drain in a typical smartphone is shortened by three to twelve hours. The heavy toll raises the question as to whether the magnetometer-based contact detection can avoid such high sensing rates while not losing the contact detection accuracy. In order to answer the question, we conduct a measurement-based study using independently produced magnetometer traces from three different

  5. Empirical Determination of Efficient Sensing Frequencies for Magnetometer-Based Continuous Human Contact Monitoring.

    Science.gov (United States)

    Kuk, Seungho; Kim, Junha; Park, Yongtae; Kim, Hyogon

    2018-04-27

    The high linear correlation between the smartphone magnetometer readings in close proximity can be exploited for physical human contact detection, which could be useful for such applications as infectious disease contact tracing or social behavior monitoring. Alternative approaches using other capabilities in smartphones have aspects that do not fit well with the human contact detection. Using Wi-Fi or cellular fingerprints have larger localization errors than close human contact distances. Bluetooth beacons could reveal the identity of the transmitter, threatening the privacy of the user. Also, using sensors such as GPS does not work for indoor contacts. However, the magnetometer correlation check works best in human contact distances that matter in infectious disease transmissions or social interactions. The omni-present geomagnetism makes it work both indoors and outdoors, and the measured magnetometer values do not easily reveal the identity and the location of the smartphone. One issue with the magnetometer-based contact detection, however, is the energy consumption. Since the contacts can take place anytime, the magnetometer sensing and recording should be running continuously. Therefore, how we address the energy requirement for the extended and continuous operation can decide the viability of the whole idea. However, then, we note that almost all existing magnetometer-based applications such as indoor location and navigation have used high sensing frequencies, ranging from 10 Hz to 200 Hz. At these frequencies, we measure that the time to complete battery drain in a typical smartphone is shortened by three to twelve hours. The heavy toll raises the question as to whether the magnetometer-based contact detection can avoid such high sensing rates while not losing the contact detection accuracy. In order to answer the question, we conduct a measurement-based study using independently produced magnetometer traces from three different countries. Specifically, we

  6. Inkjet printing-based volumetric display projecting multiple full-colour 2D patterns

    Science.gov (United States)

    Hirayama, Ryuji; Suzuki, Tomotaka; Shimobaba, Tomoyoshi; Shiraki, Atsushi; Naruse, Makoto; Nakayama, Hirotaka; Kakue, Takashi; Ito, Tomoyoshi

    2017-04-01

    In this study, a method to construct a full-colour volumetric display is presented using a commercially available inkjet printer. Photoreactive luminescence materials are minutely and automatically printed as the volume elements, and volumetric displays are constructed with high resolution using easy-to-fabricate means that exploit inkjet printing technologies. The results experimentally demonstrate the first prototype of an inkjet printing-based volumetric display composed of multiple layers of transparent films that yield a full-colour three-dimensional (3D) image. Moreover, we propose a design algorithm with 3D structures that provide multiple different 2D full-colour patterns when viewed from different directions and experimentally demonstrate prototypes. It is considered that these types of 3D volumetric structures and their fabrication methods based on widely deployed existing printing technologies can be utilised as novel information display devices and systems, including digital signage, media art, entertainment and security.

  7. Mechanical Stability of Flexible Graphene-Based Displays

    Science.gov (United States)

    2016-01-01

    The mechanical behavior of a prototype touch panel display, which consists of two layers of CVD graphene embedded into PET films, is investigated in tension and under contact-stress dynamic loading. In both cases, laser Raman spectroscopy was employed to assess the stress transfer efficiency of the embedded graphene layers. The tensile behavior was found to be governed by the “island-like” microstructure of the CVD graphene, and the stress transfer efficiency was dependent on the size of graphene “islands” but also on the yielding behavior of PET at relatively high strains. Finally, the fatigue tests, which simulate real operation conditions, showed that the maximum temperature gradient developed at the point of “finger” contact after 80 000 cycles does not exceed the glass transition temperature of the PET matrix. The effect of these results on future product development and the design of new graphene-based displays are discussed. PMID:27494211

  8. Short-Term Structured Treatment for Avoidant Personality Disorder.

    Science.gov (United States)

    Alden, Lynn

    1989-01-01

    Randomly assigned 42 men and 34 women classified as having avoidant personality disorder to one of three treatment conditions or to control group. Treatment subjects displayed significantly greater improvement on self-report and behavioral measures than did controls. Inclusion of skills-training procedures did not contribute to effects of…

  9. Hyperspectral remote sensing application for monitoring and preservation of plant ecosystems

    Science.gov (United States)

    Krezhova, Dora; Maneva, Svetla; Zdravev, Tomas; Petrov, Nikolay; Stoev, Antoniy

    Remote sensing technologies have advanced significantly at last decade and have improved the capability to gather information about Earth’s resources and environment. They have many applications in Earth observation, such as mapping and updating land-use and cover, weather forecasting, biodiversity determination, etc. Hyperspectral remote sensing offers unique opportunities in the environmental monitoring and sustainable use of natural resources. Remote sensing sensors on space-based platforms, aircrafts, or on ground, are capable of providing detailed spectral, spatial and temporal information on terrestrial ecosystems. Ground-based sensors are used to record detailed information about the land surface and to create a data base for better characterizing the objects which are being imaged by the other sensors. In this paper some applications of two hyperspectral remote sensing techniques, leaf reflectance and chlorophyll fluorescence, for monitoring and assessment of the effects of adverse environmental conditions on plant ecosystems are presented. The effect of stress factors such as enhanced UV-radiation, acid rain, salinity, viral infections applied to some young plants (potato, pea, tobacco) and trees (plums, apples, paulownia) as well as of some growth regulators were investigated. Hyperspectral reflectance and fluorescence data were collected by means of a portable fiber-optics spectrometer in the visible and near infrared spectral ranges (450-850 nm and 600-900 nm), respectively. The differences between the reflectance data of healthy (control) and injured (stressed) plants were assessed by means of statistical (Student’s t-criterion), first derivative, and cluster analysis and calculation of some vegetation indices in four most informative for the investigated species regions: green (520-580 nm), red (640-680 nm), red edge (690-720 nm) and near infrared (720-780 nm). Fluorescence spectra were analyzed at five characteristic wavelengths located at the

  10. Information Recovery Algorithm for Ground Objects in Thin Cloud Images by Fusing Guide Filter and Transfer Learning

    Directory of Open Access Journals (Sweden)

    HU Gensheng

    2018-03-01

    Full Text Available Ground object information of remote sensing images covered with thin clouds is obscure. An information recovery algorithm for ground objects in thin cloud images is proposed by fusing guide filter and transfer learning. Firstly, multi-resolution decomposition of thin cloud target images and cloud-free guidance images is performed by using multi-directional nonsubsampled dual-tree complex wavelet transform. Then the decomposed low frequency subbands are processed by using support vector guided filter and transfer learning respectively. The decomposed high frequency subbands are enhanced by using modified Laine enhancement function. The low frequency subbands output by guided filter and those predicted by transfer learning model are fused by the method of selection and weighting based on regional energy. Finally, the enhanced high frequency subbands and the fused low frequency subbands are reconstructed by using inverse multi-directional nonsubsampled dual-tree complex wavelet transform to obtain the ground object information recovery images. Experimental results of Landsat-8 OLI multispectral images show that, support vector guided filter can effectively preserve the detail information of the target images, domain adaptive transfer learning can effectively extend the range of available multi-source and multi-temporal remote sensing images, and good effects for ground object information recover are obtained by fusing guide filter and transfer learning to remove thin cloud on the remote sensing images.

  11. Measurement of Oil and Natural Gas Well Pad Enclosed Combustor Emissions Using Optical Remote Sensing Technologies

    Science.gov (United States)

    The U.S. Environmental Protection Agency (EPA), Office of Research and Development (ORD) and EPA Region 8 are collaborating under the EPA’s Regional Applied Research Effort (RARE) program to evaluate ground-based remote sensing technologies that could be used to characterize emis...

  12. Ultrafast Laser-Based Spectroscopy and Sensing: Applications in LIBS, CARS, and THz Spectroscopy

    Science.gov (United States)

    Leahy-Hoppa, Megan R.; Miragliotta, Joseph; Osiander, Robert; Burnett, Jennifer; Dikmelik, Yamac; McEnnis, Caroline; Spicer, James B.

    2010-01-01

    Ultrafast pulsed lasers find application in a range of spectroscopy and sensing techniques including laser induced breakdown spectroscopy (LIBS), coherent Raman spectroscopy, and terahertz (THz) spectroscopy. Whether based on absorption or emission processes, the characteristics of these techniques are heavily influenced by the use of ultrafast pulses in the signal generation process. Depending on the energy of the pulses used, the essential laser interaction process can primarily involve lattice vibrations, molecular rotations, or a combination of excited states produced by laser heating. While some of these techniques are currently confined to sensing at close ranges, others can be implemented for remote spectroscopic sensing owing principally to the laser pulse duration. We present a review of ultrafast laser-based spectroscopy techniques and discuss the use of these techniques to current and potential chemical and environmental sensing applications. PMID:22399883

  13. Ultrafast Laser-Based Spectroscopy and Sensing: Applications in LIBS, CARS, and THz Spectroscopy

    Directory of Open Access Journals (Sweden)

    Megan R. Leahy-Hoppa

    2010-04-01

    Full Text Available Ultrafast pulsed lasers find application in a range of spectroscopy and sensing techniques including laser induced breakdown spectroscopy (LIBS, coherent Raman spectroscopy, and terahertz (THz spectroscopy. Whether based on absorption or emission processes, the characteristics of these techniques are heavily influenced by the use of ultrafast pulses in the signal generation process. Depending on the energy of the pulses used, the essential laser interaction process can primarily involve lattice vibrations, molecular rotations, or a combination of excited states produced by laser heating. While some of these techniques are currently confined to sensing at close ranges, others can be implemented for remote spectroscopic sensing owing principally to the laser pulse duration. We present a review of ultrafast laser-based spectroscopy techniques and discuss the use of these techniques to current and potential chemical and environmental sensing applications.

  14. QR-decomposition based SENSE reconstruction using parallel architecture.

    Science.gov (United States)

    Ullah, Irfan; Nisar, Habab; Raza, Haseeb; Qasim, Malik; Inam, Omair; Omer, Hammad

    2018-04-01

    Magnetic Resonance Imaging (MRI) is a powerful medical imaging technique that provides essential clinical information about the human body. One major limitation of MRI is its long scan time. Implementation of advance MRI algorithms on a parallel architecture (to exploit inherent parallelism) has a great potential to reduce the scan time. Sensitivity Encoding (SENSE) is a Parallel Magnetic Resonance Imaging (pMRI) algorithm that utilizes receiver coil sensitivities to reconstruct MR images from the acquired under-sampled k-space data. At the heart of SENSE lies inversion of a rectangular encoding matrix. This work presents a novel implementation of GPU based SENSE algorithm, which employs QR decomposition for the inversion of the rectangular encoding matrix. For a fair comparison, the performance of the proposed GPU based SENSE reconstruction is evaluated against single and multicore CPU using openMP. Several experiments against various acceleration factors (AFs) are performed using multichannel (8, 12 and 30) phantom and in-vivo human head and cardiac datasets. Experimental results show that GPU significantly reduces the computation time of SENSE reconstruction as compared to multi-core CPU (approximately 12x speedup) and single-core CPU (approximately 53x speedup) without any degradation in the quality of the reconstructed images. Copyright © 2018 Elsevier Ltd. All rights reserved.

  15. Integrating the avoidance of forest degradation into systematic conservation planning in the Eastern Amazon

    Science.gov (United States)

    Ferreira, J.; Barlow, J.; Thompson, J.; Berenguer, E.; Aragão, L. E.; Lees, A.; Lennox, G.; Brancalion, P.; Ferraz, S.; Moura, N.; Oliveira, V. H.; Louzada, J.; Solar, R.; Nunes, S.; Parry, L.; Fonseca, T.; Garrett, R.; Vieira, I.; MacNally, R.; Gardner, T.

    2017-12-01

    Undisturbed forests are becoming increasingly rare in the tropics. The area of forest degraded by some form of disturbance, such as logging or fire, in the Brazilian Amazon now greatly exceeds that which had been deforested. Yet forest policy in the Amazon, as elsewhere in the tropics, remains overwhelmingly focused curbing the rate of forest loss without considering impacts on forest quality. We use a unique data set from the Sustainable Amazon Network (RAS), in the eastern Brazilian Amazon to assess the impacts of forest disturbance on biodiversity and assess the benefits of including avoided degradation measures in conservation planning. Biodiversity data on trees and fauna from two large regions, Santarém and Paragominas, were combined with remote sensing data to model biodiversity patterns as well as estimates of above-ground carbon stocks across a range of land-use types and forest conditions. We found that impact of forest disturbance on biodiversity loss in the state of Pará equates to double that lost from deforestation alone, -the equivalent of losing 92,000-139,000 km2 of primary forest. We found a strong positive relationship between increasing carbon stocks and higher biodiversity in varyingly disturbed forests. Simulations demonstrated that a carbon-focused conservation strategy is least effective at conserving biodiversity in the least disturbed forests, highlighting the importance of on-the-ground biodiversity surveys to prioritise conservation investments in the most species rich forests. We explored trade-offs among management actions to guide priorities for habitat protection, avoided degradation and restoration and found that where restoration imposes significant opportunity and implementation costs, efforts to avoid and reverse the degradation of existing forests can deliver greater returns on investment for biodiversity conservation. Systemic planning of forest management options at regional scales can substantially improve biodiversity

  16. The application of autostereoscopic display in smart home system based on mobile devices

    Science.gov (United States)

    Zhang, Yongjun; Ling, Zhi

    2015-03-01

    Smart home is a system to control home devices which are more and more popular in our daily life. Mobile intelligent terminals based on smart homes have been developed, make remote controlling and monitoring possible with smartphones or tablets. On the other hand, 3D stereo display technology developed rapidly in recent years. Therefore, a iPad-based smart home system adopts autostereoscopic display as the control interface is proposed to improve the userfriendliness of using experiences. In consideration of iPad's limited hardware capabilities, we introduced a 3D image synthesizing method based on parallel processing with Graphic Processing Unit (GPU) implemented it with OpenGL ES Application Programming Interface (API) library on IOS platforms for real-time autostereoscopic displaying. Compared to the traditional smart home system, the proposed system applied autostereoscopic display into smart home system's control interface enhanced the reality, user-friendliness and visual comfort of interface.

  17. Avoidance and Overuse of Indonesian Language among Balinese Children

    Directory of Open Access Journals (Sweden)

    Wayan Pageyasa

    2017-10-01

    Full Text Available The use of Indonesian language by children who speak the Balinese language, especially for children who live in rural areas is quite difficult. This is because their Balinese language is much different from Indonesian language. If they speak Indonesian language, they have to fall back to the language first. That is, language transfer process will take place from Balinese language to Indonesian language. This research aims to describe two phenomena of the language transfer process, namely avoidance and overuse (excessive use. Qualitative data were obtained from one Balinese child, namely Gede. Gede’s daily conversations were recorded to be analyzed. The researcher also used field notes. The results show that there is indeed avoidance and overuse in the use of Indonesian language by Gede.  The teachers must be aware of the student's avoidance and overuse of Indonesian language, then the teacher can choose a contextual teaching method that best fits their students’ need in order to enable them to cope with the avoidance and overuse in learning the second language. In conclusion, the Balinese child’s avoidance and overuse, displayed in his use of Indonesian Language, is a concequence of his prior knowledge of his first language (L1 as well as his cultural awareness.  Teachers should facilitate their students’ second language (L2 learning by being aware of their L1 prior knowledge and culture.

  18. Palladium and platinum-based nanoparticle functional sensor layers for selective H2 sensing

    Science.gov (United States)

    Ohodnicki, Jr., Paul R.; Baltrus, John P.; Brown, Thomas D.

    2017-07-04

    The disclosure relates to a plasmon resonance-based method for H.sub.2 sensing in a gas stream utilizing a hydrogen sensing material. The hydrogen sensing material is comprises Pd-based or Pt-based nanoparticles having an average nanoparticle diameter of less than about 100 nanometers dispersed in an inert matrix having a bandgap greater than or equal to 5 eV, and an oxygen ion conductivity less than approximately 10.sup.-7 S/cm at a temperature of 700.degree. C. Exemplary inert matrix materials include SiO.sub.2, Al.sub.2O.sub.3, and Si.sub.3N.sub.4 as well as modifications to modify the effective refractive indices through combinations and/or doping of such materials. The hydrogen sensing material utilized in the method of this disclosure may be prepared using means known in the art for the production of nanoparticles dispersed within a supporting matrix including sol-gel based wet chemistry techniques, impregnation techniques, implantation techniques, sputtering techniques, and others.

  19. Effect of display location on control-display stereotype strength for translational and rotational controls with linear displays.

    Science.gov (United States)

    Chan, Alan H S; Hoffmann, Errol R

    2015-01-01

    Experiments were designed to investigate the effects of control type and display location, relative to the operator, on the strength of control/display stereotypes. The Worringham and Beringer Visual Field principle and an extension of this principle for rotary controls (Hoffmann E.R., and Chan A.H.S. 2013). "The Worringham and Beringer 'Visual Field' Principle for Rotary Controls. Ergonomics." 56 (10): 1620-1624) indicated that, for a number of different control types (rotary and lever) on different planes, there should be no significant effect of the display location relative to the seated operator. Past data were surveyed and stereotype strengths listed. Experiments filled gaps where data are not available. Six different control types and seven display locations were used, as in the Frame of Reference Transformation Tool (FORT) model of Wickens et al. (Wickens, C.D., Keller, J.W., and Small, R.L. (2010). "Left. No, Right! Development of the Frame of Reference Transformation Tool (FORT)." Proceedings of the Human Factors and Ergonomics Society 54th Annual Meeting September 2010, 54: 1022-1026). Control/display arrangements with high stereotype strengths were evaluated yielding data for designers of complex control/display arrangements where the control and display are in different planes and for where the operator is moving. It was found possible to predict display/control arrangements with high stereotype strength, based on past data. Practitioner Summary: Controls and displays in complex arrangements need to have high compatibility. These experiments provide arrangements for six different controls (rotary and translational) and seven different display locations relative to the operator.

  20. Biologically inspired collision avoidance system for unmanned vehicles

    Science.gov (United States)

    Ortiz, Fernando E.; Graham, Brett; Spagnoli, Kyle; Kelmelis, Eric J.

    2009-05-01

    In this project, we collaborate with researchers in the neuroscience department at the University of Delaware to develop an Field Programmable Gate Array (FPGA)-based embedded computer, inspired by the brains of small vertebrates (fish). The mechanisms of object detection and avoidance in fish have been extensively studied by our Delaware collaborators. The midbrain optic tectum is a biological multimodal navigation controller capable of processing input from all senses that convey spatial information, including vision, audition, touch, and lateral-line (water current sensing in fish). Unfortunately, computational complexity makes these models too slow for use in real-time applications. These simulations are run offline on state-of-the-art desktop computers, presenting a gap between the application and the target platform: a low-power embedded device. EM Photonics has expertise in developing of high-performance computers based on commodity platforms such as graphic cards (GPUs) and FPGAs. FPGAs offer (1) high computational power, low power consumption and small footprint (in line with typical autonomous vehicle constraints), and (2) the ability to implement massively-parallel computational architectures, which can be leveraged to closely emulate biological systems. Combining UD's brain modeling algorithms and the power of FPGAs, this computer enables autonomous navigation in complex environments, and further types of onboard neural processing in future applications.

  1. Obstacle-avoiding robot with IR and PIR motion sensors

    Science.gov (United States)

    Ismail, R.; Omar, Z.; Suaibun, S.

    2016-10-01

    Obstacle avoiding robot was designed, constructed and programmed which may be potentially used for educational and research purposes. The developed robot will move in a particular direction once the infrared (IR) and the PIR passive infrared (PIR) sensors sense a signal while avoiding the obstacles in its path. The robot can also perform desired tasks in unstructured environments without continuous human guidance. The hardware was integrated in one application board as embedded system design. The software was developed using C++ and compiled by Arduino IDE 1.6.5. The main objective of this project is to provide simple guidelines to the polytechnic students and beginners who are interested in this type of research. It is hoped that this robot could benefit students who wish to carry out research on IR and PIR sensors.

  2. Non-binary Colour Modulation for Display Device Based on Phase Change Materials

    Science.gov (United States)

    Ji, Hong-Kai; Tong, Hao; Qian, Hang; Hui, Ya-Juan; Liu, Nian; Yan, Peng; Miao, Xiang-Shui

    2016-12-01

    A reflective-type display device based on phase change materials is attractive because of its ultrafast response time and high resolution compared with a conventional display device. This paper proposes and demonstrates a unique display device in which multicolour changing can be achieved on a single device by the selective crystallization of double layer phase change materials. The optical contrast is optimized by the availability of a variety of film thicknesses of two phase change layers. The device exhibits a low sensitivity to the angle of incidence, which is important for display and colour consistency. The non-binary colour rendering on a single device is demonstrated for the first time using optical excitation. The device shows the potential for ultrafast display applications.

  3. Non-binary Colour Modulation for Display Device Based on Phase Change Materials.

    Science.gov (United States)

    Ji, Hong-Kai; Tong, Hao; Qian, Hang; Hui, Ya-Juan; Liu, Nian; Yan, Peng; Miao, Xiang-Shui

    2016-12-19

    A reflective-type display device based on phase change materials is attractive because of its ultrafast response time and high resolution compared with a conventional display device. This paper proposes and demonstrates a unique display device in which multicolour changing can be achieved on a single device by the selective crystallization of double layer phase change materials. The optical contrast is optimized by the availability of a variety of film thicknesses of two phase change layers. The device exhibits a low sensitivity to the angle of incidence, which is important for display and colour consistency. The non-binary colour rendering on a single device is demonstrated for the first time using optical excitation. The device shows the potential for ultrafast display applications.

  4. Solar Avoided Cost Solution SunShot 6 Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Tucker, John [Genability, San Francisco, CA (United States); Danziger, Eric [Genability, San Francisco, CA (United States)

    2014-01-29

    The core objectives of this project were two separate but integrated products, collectively providing game-changing Avoided Cost capabilities. The first was a kit of avoided cost tools and data that any solar provider can use a-lacarte or as a whole. It’s open and easily accessible nature allows the rapid and accurate calculation of avoided cost in whatever context and software that make sense (“Typical and Avoided Cost Tools”). This kit includes a dataset of typical energy rates, costs and usage that can be used for solar prospecting, lead generation and any situation where data about an opportunity is missing or imperfect. The second is a web application and related APIs specifically built for solar providers to radically streamline their lead-to-sale process (“Solar Provider Module”). The typical and Avoided Cost tools are built directly into this, and allow for solar providers to track their opportunities, collaborate with their installers and financiers, and close more sales faster.

  5. Uncertainty of Forest Biomass Estimates in North Temperate Forests Due to Allometry: Implications for Remote Sensing

    Directory of Open Access Journals (Sweden)

    Razi Ahmed

    2013-06-01

    Full Text Available Estimates of above ground biomass density in forests are crucial for refining global climate models and understanding climate change. Although data from field studies can be aggregated to estimate carbon stocks on global scales, the sparsity of such field data, temporal heterogeneity and methodological variations introduce large errors. Remote sensing measurements from spaceborne sensors are a realistic alternative for global carbon accounting; however, the uncertainty of such measurements is not well known and remains an active area of research. This article describes an effort to collect field data at the Harvard and Howland Forest sites, set in the temperate forests of the Northeastern United States in an attempt to establish ground truth forest biomass for calibration of remote sensing measurements. We present an assessment of the quality of ground truth biomass estimates derived from three different sets of diameter-based allometric equations over the Harvard and Howland Forests to establish the contribution of errors in ground truth data to the error in biomass estimates from remote sensing measurements.

  6. Stereo visualization in the ground segment tasks of the science space missions

    Science.gov (United States)

    Korneva, Natalia; Nazarov, Vladimir; Mogilevsky, Mikhail; Nazirov, Ravil

    The ground segment is one of the key components of any science space mission. Its functionality substantially defines the scientific effectiveness of the experiment as a whole. And it should be noted that its outstanding feature (in contrast to the other information systems of the scientific space projects) is interaction between researcher and project information system in order to interpret data being obtained during experiments. Therefore the ability to visualize the data being processed is essential prerequisite for ground segment's software and the usage of modern technological solutions and approaches in this area will allow increasing science return in general and providing a framework for new experiments creation. Mostly for the visualization of data being processed 2D and 3D graphics are used that is caused by the traditional visualization tools capabilities. Besides that the stereo data visualization methods are used actively in solving some tasks. However their usage is usually limited to such tasks as visualization of virtual and augmented reality, remote sensing data processing and suchlike. Low prevalence of stereo visualization methods in solving science ground segment tasks is primarily explained by extremely high cost of the necessary hardware. But recently appeared low cost hardware solutions for stereo visualization based on the page-flip method of views separation. In this case it seems promising to use the stereo visualization as an instrument for investigation of a wide range of problems, mainly for stereo visualization of complex physical processes as well as mathematical abstractions and models. The article is concerned with an attempt to use this approach. It describes the details and problems of using stereo visualization (page-flip method based on NVIDIA 3D Vision Kit, graphic processor GeForce) for display of some datasets of magnetospheric satellite onboard measurements and also in development of the software for manual stereo matching.

  7. Ratiometric glucose sensing based on fluorescent oxygen films and glucose oxidase

    OpenAIRE

    Fengyu Su; Liqiang Zhang; Xiangxing Kong; Fred Lee; Yanqing Tian; Deirdre R. Meldrum

    2017-01-01

    A new two-layer sensor film was constructed for sensing glucose based on glucose oxidase and oxygen sensing material. The first layer of film containing the oxygen sensor and intra-reference material was polymerized, then the second layer of glucose oxidase and glutaraldehyde was formed on the oxygen sensor layer. The two-layer sensor film has a resolution up to 0.05 mM and a detection range from 0 to 5 mM to glucose. The effects of pH and temperature on the sensing performance were systemati...

  8. Grounded Theory sebagai Metode Riset “Realitas Tertambah” di Museum Fatahillah

    Directory of Open Access Journals (Sweden)

    Leonardo Widya

    2014-03-01

    Full Text Available Augmented Reality (AR is part of the science of visual communication design/graphic design through theaddition of images on the real world with virtual information to enhance one’s senses with the help of “smart glasses”with three general characteristics: 1. The combination of real environment with virtual objects, 2. Interactivedisplay, 3. Display in 3D. Qualitative research methods and grounded theory approach in the real environmentin the area of Jakarta Fatahillah museum, discovered a new theory as a basis the idea that Visual PrototypingAugmented Reality technique with image manipulation-image nuanced Kota Tua as Jakarta Icon. The idea ofexploiting foreign tourists enriching way to learn more about Indonesia through social networking in a virtual worldstrategies to increase tourism.

  9. Dynamic tire pressure sensor for measuring ground vibration.

    Science.gov (United States)

    Wang, Qi; McDaniel, James Gregory; Wang, Ming L

    2012-11-07

    This work presents a convenient and non-contact acoustic sensing approach for measuring ground vibration. This approach, which uses an instantaneous dynamic tire pressure sensor (DTPS), possesses the capability to replace the accelerometer or directional microphone currently being used for inspecting pavement conditions. By measuring dynamic pressure changes inside the tire, ground vibration can be amplified and isolated from environmental noise. In this work, verifications of the DTPS concept of sensing inside the tire have been carried out. In addition, comparisons between a DTPS, ground-mounted accelerometer, and directional microphone are made. A data analysis algorithm has been developed and optimized to reconstruct ground acceleration from DTPS data. Numerical and experimental studies of this DTPS reveal a strong potential for measuring ground vibration caused by a moving vehicle. A calibration of transfer function between dynamic tire pressure change and ground acceleration may be needed for different tire system or for more accurate application.

  10. Intercomparison of Unmanned Aerial Vehicle and Ground-Based Narrow Band Spectrometers Applied to Crop Trait Monitoring in Organic Potato Production

    Directory of Open Access Journals (Sweden)

    Marston Héracles Domingues Franceschini

    2017-06-01

    Full Text Available Vegetation properties can be estimated using optical sensors, acquiring data on board of different platforms. For instance, ground-based and Unmanned Aerial Vehicle (UAV-borne spectrometers can measure reflectance in narrow spectral bands, while different modelling approaches, like regressions fitted to vegetation indices, can relate spectra with crop traits. Although monitoring frameworks using multiple sensors can be more flexible, they may result in higher inaccuracy due to differences related to the sensors characteristics, which can affect information sampling. Also organic production systems can benefit from continuous monitoring focusing on crop management and stress detection, but few studies have evaluated applications with this objective. In this study, ground-based and UAV spectrometers were compared in the context of organic potato cultivation. Relatively accurate estimates were obtained for leaf chlorophyll (RMSE = 6.07 µg·cm−2, leaf area index (RMSE = 0.67 m2·m−2, canopy chlorophyll (RMSE = 0.24 g·m−2 and ground cover (RMSE = 5.5% using five UAV-based data acquisitions, from 43 to 99 days after planting. These retrievals are slightly better than those derived from ground-based measurements (RMSE = 7.25 µg·cm−2, 0.85 m2·m−2, 0.28 g·m−2 and 6.8%, respectively, for the same period. Excluding observations corresponding to the first acquisition increased retrieval accuracy and made outputs more comparable between sensors, due to relatively low vegetation cover on this date. Intercomparison of vegetation indices indicated that indices based on the contrast between spectral bands in the visible and near-infrared, like OSAVI, MCARI2 and CIg provided, at certain extent, robust outputs that could be transferred between sensors. Information sampling at plot level by both sensing solutions resulted in comparable discriminative potential concerning advanced stages of late blight incidence. These results indicate that optical

  11. Combining the Pixel-based and Object-based Methods for Building Change Detection Using High-resolution Remote Sensing Images

    Directory of Open Access Journals (Sweden)

    ZHANG Zhiqiang

    2018-01-01

    Full Text Available Timely and accurate change detection of buildings provides important information for urban planning and management.Accompanying with the rapid development of satellite remote sensing technology,detecting building changes from high-resolution remote sensing images have received wide attention.Given that pixel-based methods of change detection often lead to low accuracy while object-based methods are complicated for uses,this research proposes a method that combines pixel-based and object-based methods for detecting building changes from high-resolution remote sensing images.First,based on the multiple features extracted from the high-resolution images,a random forest classifier is applied to detect changed building at the pixel level.Then,a segmentation method is applied to segement the post-phase remote sensing image and to get post-phase image objects.Finally,both changed building at the pixel level and post-phase image objects are fused to recognize the changed building objects.Multi-temporal QuickBird images are used as experiment data for building change detection with high-resolution remote sensing images,the results indicate that the proposed method could reduce the influence of environmental difference,such as light intensity and view angle,on building change detection,and effectively improve the accuracies of building change detection.

  12. Purely temporal figure-ground segregation.

    Science.gov (United States)

    Kandil, F I; Fahle, M

    2001-05-01

    Visual figure-ground segregation is achieved by exploiting differences in features such as luminance, colour, motion or presentation time between a figure and its surround. Here we determine the shortest delay times required for figure-ground segregation based on purely temporal features. Previous studies usually employed stimulus onset asynchronies between figure- and ground-containing possible artefacts based on apparent motion cues or on luminance differences. Our stimuli systematically avoid these artefacts by constantly showing 20 x 20 'colons' that flip by 90 degrees around their midpoints at constant time intervals. Colons constituting the background flip in-phase whereas those constituting the target flip with a phase delay. We tested the impact of frequency modulation and phase reduction on target detection. Younger subjects performed well above chance even at temporal delays as short as 13 ms, whilst older subjects required up to three times longer delays in some conditions. Figure-ground segregation can rely on purely temporal delays down to around 10 ms even in the absence of luminance and motion artefacts, indicating a temporal precision of cortical information processing almost an order of magnitude lower than the one required for some models of feature binding in the visual cortex [e.g. Singer, W. (1999), Curr. Opin. Neurobiol., 9, 189-194]. Hence, in our experiment, observers are unable to use temporal stimulus features with the precision required for these models.

  13. Pooling the ground: Understanding and coordination in collective sense making.

    Directory of Open Access Journals (Sweden)

    Joanna eRaczaszek-Leonardi

    2014-11-01

    Full Text Available Common ground is most often understood as the sum of mutually known beliefs, knowledge and suppositions among the participants in a conversation. It explains why participants do not mention things that should be obvious to both. In some accounts of communication, reaching a mutual understanding, i.e., broadening the common ground, is posed as the ultimate goal of linguistic interactions. Yet, congruent with the more pragmatic views of linguistic behavior, in which language is treated as social coordination, understanding each other is not the purpose (or not the sole purpose of linguistic interactions. This purpose is seen as at least twofold (e.g. Fusaroli, Rączaszek-Leonardi & Tylén, 2014: to maintain the systemic character of a conversing dyad and to organize it into a functional synergy in the face of tasks posed for a dyadic system as a whole. It seems that the notion of common ground may not be sufficient to address this dual character of interaction. In situated communication, in which meaning is created in the very process of interaction, both common (sameness and privileged (diversity information must be pooled task-dependently and across participants. In this paper, we analyze the definitions of common and privileged ground and propose extensions that may facilitate a theoretical account of agents that coordinate via linguistic communication. To illustrate the usefulness of this augmented framework, we apply it to one of the recurrent issues in psycholinguistic research, namely the problem of perspective-taking in dialogue, and draw conclusions for the broader problem of audience design.

  14. Background factors associated with problem avoidance behavior in healthy partners of breast cancer patients.

    Science.gov (United States)

    Shiozaki, Mariko; Sanjo, Makiko; Hirai, Kei

    2017-08-01

    We evaluated avoidance behaviors of healthy partners of breast cancer patients and sought to (1) describe men's perception of their own avoidance behavior and (2) identify the background factors associated with such behavior. An Internet-based survey was conducted, and analysis was performed on the responses of 368 male spouses of female breast cancer patients. Thirty to forty percent of spouses had some type of problem avoidance behavior toward their wives. There was a high correlation (r = 0.70, P problem avoidance behavior at the time of diagnosis and subsequent problem behavior (mean follow-up period after diagnosis: 1.3 + 1.1 years). The characteristics of spouses with avoidant behaviors included having wives with recurrence, having wives treated with anticancer drug therapy or total resection, and having their own experience of cancer. Covariance structure analysis revealed 2 factors related to the background of spouses with problem avoidance behavior: (1) having a sense of difficulty in coping (beta = 0.68, P problem avoidance behavior among healthy male partners of breast cancer patients is common and correlates with difficulty coping and a poor marital relationship. It is important to address both the problem avoidance behavior itself and to support couples early, before this behavior surfaces. Copyright © 2016 John Wiley & Sons, Ltd.

  15. Ground-based inhibition: Suppressive perceptual mechanisms interact with top-down attention to reduce distractor interference.

    Science.gov (United States)

    Wager, Erica; Peterson, Mary A; Folstein, Jonathan R; Scalf, Paige E

    2015-01-01

    Successful attentional function requires inhibition of distracting information (e.g., Deutsch & Deutsch, 1963). Similarly, perceptual segregation of the visual world into figure and ground entails ground suppression (e.g., Likova & Tyler, 2008; Peterson & Skow, 2008). Here, we ask whether the suppressive processes of attention and perception-distractor inhibition and ground suppression-interact to more effectively insulate task performance from interfering information. We used a variant of the Eriksen flanker paradigm to assess the efficacy of distractor inhibition. Participants indicated the right/left orientation of a central arrow, which could be flanked by congruent, neutral, or incongruent stimuli. We manipulated the degree to which the ground region of a display was suppressed and measured the influence of this manipulation on the efficacy with which participants could inhibit responses from incongruent flankers. Greater ground suppression reduced the influence on target identification of interfering, incongruent information, but not that of facilitative, congruent information. These data are the first to show that distractor inhibition interacts with ground suppression to improve attentional function.

  16. Highly Sensitive Temperature Sensors Based on Fiber-Optic PWM and Capacitance Variation Using Thermochromic Sensing Membrane

    Directory of Open Access Journals (Sweden)

    Md. Rajibur Rahaman Khan

    2016-07-01

    Full Text Available In this paper, we propose a temperature/thermal sensor that contains a Rhodamine-B sensing membrane. We applied two different sensing methods, namely, fiber-optic pulse width modulation (PWM and an interdigitated capacitor (IDC-based temperature sensor to measure the temperature from 5 °C to 100 °C. To the best of our knowledge, the fiber-optic PWM-based temperature sensor is reported for the first time in this study. The proposed fiber-optic PWM temperature sensor has good sensing ability; its sensitivity is ~3.733 mV/°C. The designed temperature-sensing system offers stable sensing responses over a wide dynamic range, good reproducibility properties with a relative standard deviation (RSD of ~0.021, and the capacity for a linear sensing response with a correlation coefficient of R2 ≈ 0.992 over a wide sensing range. In our study, we also developed an IDC temperature sensor that is based on the capacitance variation principle as the IDC sensing element is heated. We compared the performance of the proposed temperature-sensing systems with different fiber-optic temperature sensors (which are based on the fiber-optic wavelength shift method, the long grating fiber-optic Sagnac loop, and probe type fiber-optics in terms of sensitivity, dynamic range, and linearity. We observed that the proposed sensing systems have better sensing performance than the above-mentioned sensing system.

  17. Ontology-based classification of remote sensing images using spectral rules

    Science.gov (United States)

    Andrés, Samuel; Arvor, Damien; Mougenot, Isabelle; Libourel, Thérèse; Durieux, Laurent

    2017-05-01

    Earth Observation data is of great interest for a wide spectrum of scientific domain applications. An enhanced access to remote sensing images for "domain" experts thus represents a great advance since it allows users to interpret remote sensing images based on their domain expert knowledge. However, such an advantage can also turn into a major limitation if this knowledge is not formalized, and thus is difficult for it to be shared with and understood by other users. In this context, knowledge representation techniques such as ontologies should play a major role in the future of remote sensing applications. We implemented an ontology-based prototype to automatically classify Landsat images based on explicit spectral rules. The ontology is designed in a very modular way in order to achieve a generic and versatile representation of concepts we think of utmost importance in remote sensing. The prototype was tested on four subsets of Landsat images and the results confirmed the potential of ontologies to formalize expert knowledge and classify remote sensing images.

  18. The separation-combination method of linear structures in remote sensing image interpretation and its application

    International Nuclear Information System (INIS)

    Liu Linqin

    1991-01-01

    The separation-combination method a new kind of analysis method of linear structures in remote sensing image interpretation is introduced taking northwestern Fujian as the example, its practical application is examined. The practice shows that application results not only reflect intensities of linear structures in overall directions at different locations, but also contribute to the zonation of linear structures and display their space distribution laws. Based on analyses of linear structures, it can provide more information concerning remote sensing on studies of regional mineralization laws and the guide to ore-finding combining with mineralization

  19. 618-10 Burial Ground Trench Remediation and 618-10 and 618-11 Burial Ground Nonintrusive Characterization of Vertical Pipe Units Lessons Learned

    Energy Technology Data Exchange (ETDEWEB)

    Darby, J. W.

    2012-06-28

    A “lessons learned” is a noteworthy practice or innovative approach that is captured and shared to promote repeat application, or an adverse work practice/experience that is captured and shared to avoid reoccurrence. This document provides the lessons learned identified by the 618-10 Burial Ground trench remediation and the 618-10 and 618-11 Burial Ground nonintrusive characterization of the vertical pipe units (VPUs).

  20. Tracking morphological changes and slope instability using spaceborne and ground-based SAR data

    Science.gov (United States)

    Di Traglia, Federico; Nolesini, Teresa; Ciampalini, Andrea; Solari, Lorenzo; Frodella, William; Bellotti, Fernando; Fumagalli, Alfio; De Rosa, Giuseppe; Casagli, Nicola

    2018-01-01

    Stromboli (Aeolian Archipelago, Italy) is an active volcano that is frequently affected by moderate to large mass wasting, which has occasionally triggered tsunamis. With the aim of understanding the relationship between the geomorphologic evolution and slope instability of Stromboli, remote sensing information from space-born Synthetic Aperture Radar (SAR) change detection and interferometry (InSAR) () and Ground Based InSAR (GBInSAR) was compared with field observations and morphological analyses. Ground reflectivity and SqueeSAR™ (an InSAR algorithm for surface deformation monitoring) displacement measurements from X-band COSMO-SkyMed satellites (CSK) were analysed together with displacement measurements from a permanent-sited, Ku-band GBInSAR system. Remote sensing results were compared with a preliminary morphological analysis of the Sciara del Fuoco (SdF) steep volcanic flank, which was carried out using a high-resolution Digital Elevation Model (DEM). Finally, field observations, supported by infrared thermographic surveys (IRT), allowed the interpretation and validation of remote sensing data. The analysis of the entire dataset (collected between January 2010 and December 2014) covers a period characterized by a low intensity of Strombolian activity. This period was punctuated by the occurrence of lava overflows, occurring from the crater terrace evolving downslope toward SdF, and flank eruptions, such as the 2014 event. The amplitude of the CSK images collected between February 22nd, 2010, and December 18th, 2014, highlights that during periods characterized by low-intensity Strombolian activity, the production of materials ejected from the crater terrace towards the SdF is generally low, and erosion is the prevailing process mainly affecting the central sector of the SdF. CSK-SqueeSAR™ and GBInSAR data allowed the identification of low displacements in the SdF, except for high displacement rates (up to 1.5 mm/h) that were measured following both lava

  1. The Impact of Integrated Maneuver Guidance Information on UAS Pilots Performing the Detect and Avoid Task

    Science.gov (United States)

    Rorie, Conrad; Fern, Lisa

    2015-01-01

    The integrated human-in-the-loop (iHITL) simulation examined the effect of four different Detect-and-Avoid (DAA) display concepts on unmanned aircraft system (UAS) pilots' ability to maintain safe separation. The displays varied in the type and amount of guidance they provided to pilots. The study's background and methodology are discussed, followed by the 'measured response' data (i.e., pilots' end-to-end response time in reacting to traffic alerts on their DAA display). Results indicate that display type had a significant impact on how long pilot's spent interacting with the interface (i.e., edit times).

  2. Developments in Earth Observation data reception, dissemination and archival at National Remote Sensing Agency

    Science.gov (United States)

    Radhakrishnan, K.; Manjunath, A. S.; Kumar, Anil

    2009-10-01

    With the rapid advancement in remote sensing technology and corresponding applications, the Earth Observation Ground Segment has undergone a significant change at NRSA. From dedicated data acquisition and processing systems, we have realized multi-mission data acquisition quick look and browse systems and also multi-mission integrated information management systems. Front end of data reception station has been upgraded to handle wider bandwidth and data rates up to 320 Mbps for near future missions such as the Radar Imaging Satellite (RISAT). Antenna, feed, down converters and RF chain have been upgraded. To cater to multi-mission scenario mission independent, fully configurable demodulator/bit synchs have been deployed. For handling data acquisition in multi-satellite scenario where in data from 5 to 6 remote sensing satellites are to be received almost simultaneously, automation of operations has been incorporated towards station configuration to avoid manual errors. From media-based data handling, there has been a shift towards net centric data handling among the various work centers such as user order processing, data processing systems, special processing systems, data quality evaluation, and product quality control work centers. The turn around time for dissemination of user desired data products has been improved from two weeks to one day. Presently a state of the art integrated environment has been envisaged which will bring down the turn around time for the supply of data products significantly. Automation has been incorporated at both data acquisition and data processing to improve the product throughput. Presently NRSA is catering to a demand of about 30,000 data products per annum and in the next two years it is aimed to reach a level of 50,000 products per annum by realizing the integrated multi-mission ground system for earth observation (IMGEOS). This will significantly modify the entire data production and dissemination chain so that data can be

  3. Monitoring of "all-weather" evapotranspiration using optical and passive microwave remote sensing imagery over the River Source Region in Southwest China

    Science.gov (United States)

    Ma, Y.; Liu, S.

    2017-12-01

    Accurate estimation of surface evapotranspiration (ET) with high quality is one of the biggest obstacles for routine applications of remote sensing in eco-hydrological studies and water resource management at basin scale. However, many aspects urgently need to deeply research, such as the applicability of the ET models, the parameterization schemes optimization at the regional scale, the temporal upscaling, the selecting and developing of the spatiotemporal data fusion method and ground-based validation over heterogeneous land surfaces. This project is based on the theoretically robust surface energy balance system (SEBS) model, which the model mechanism need further investigation, including the applicability and the influencing factors, such as local environment, and heterogeneity of the landscape, for improving estimation accuracy. Due to technical and budget limitations, so far, optical remote sensing data is missing due to frequent cloud contamination and other poor atmospheric conditions in Southwest China. Here, a multi-source remote sensing data fusion method (ESTARFM: Enhanced Spatial and Temporal Adaptive Reflectance Fusion Model) method will be proposed through blending multi-source remote sensing data acquired by optical, and passive microwave remote sensors on board polar satellite platforms. The accurate "all-weather" ET estimation will be carried out for daily ET of the River Source Region in Southwest China, and then the remotely sensed ET results are overlapped with the footprint-weighted images of EC (eddy correlation) for ground-based validation.

  4. Information Display: Considerations for Designing Modern Computer-Based Display Systems

    International Nuclear Information System (INIS)

    O'Hara, J.; Pirus, D.; Beltracchi, L.

    2003-01-01

    OAK- B135 To help nuclear utilities and suppliers design and implement plant information management systems and displays that provide accurate and timely information and require minimal navigation and interface management

  5. Remotely Sensed Active Layer Thickness (ReSALT at Barrow, Alaska Using Interferometric Synthetic Aperture Radar

    Directory of Open Access Journals (Sweden)

    Kevin Schaefer

    2015-03-01

    Full Text Available Active layer thickness (ALT is a critical parameter for monitoring the status of permafrost that is typically measured at specific locations using probing, in situ temperature sensors, or other ground-based observations. Here we evaluated the Remotely Sensed Active Layer Thickness (ReSALT product that uses the Interferometric Synthetic Aperture Radar technique to measure seasonal surface subsidence and infer ALT around Barrow, Alaska. We compared ReSALT with ground-based ALT obtained using probing and calibrated, 500 MHz Ground Penetrating Radar at multiple sites around Barrow. ReSALT accurately reproduced observed ALT within uncertainty of the GPR and probing data in ~76% of the study area. However, ReSALT was less than observed ALT in ~22% of the study area with well-drained soils and in ~1% of the area where soils contained gravel. ReSALT was greater than observed ALT in some drained thermokarst lake basins representing ~1% of the area. These results indicate remote sensing techniques based on InSAR could be an effective way to measure and monitor ALT over large areas on the Arctic coastal plain.

  6. Dynamic Obstacle Avoidance for Unmanned Underwater Vehicles Based on an Improved Velocity Obstacle Method

    Directory of Open Access Journals (Sweden)

    Wei Zhang

    2017-11-01

    Full Text Available In view of a dynamic obstacle environment with motion uncertainty, we present a dynamic collision avoidance method based on the collision risk assessment and improved velocity obstacle method. First, through the fusion optimization of forward-looking sonar data, the redundancy of the data is reduced and the position, size and velocity information of the obstacles are obtained, which can provide an accurate decision-making basis for next-step collision avoidance. Second, according to minimum meeting time and the minimum distance between the obstacle and unmanned underwater vehicle (UUV, this paper establishes the collision risk assessment model, and screens key obstacles to avoid collision. Finally, the optimization objective function is established based on the improved velocity obstacle method, and a UUV motion characteristic is used to calculate the reachable velocity sets. The optimal collision speed of UUV is searched in velocity space. The corresponding heading and speed commands are calculated, and outputted to the motion control module. The above is the complete dynamic obstacle avoidance process. The simulation results show that the proposed method can obtain a better collision avoidance effect in the dynamic environment, and has good adaptability to the unknown dynamic environment.

  7. Remote sensing image segmentation based on Hadoop cloud platform

    Science.gov (United States)

    Li, Jie; Zhu, Lingling; Cao, Fubin

    2018-01-01

    To solve the problem that the remote sensing image segmentation speed is slow and the real-time performance is poor, this paper studies the method of remote sensing image segmentation based on Hadoop platform. On the basis of analyzing the structural characteristics of Hadoop cloud platform and its component MapReduce programming, this paper proposes a method of image segmentation based on the combination of OpenCV and Hadoop cloud platform. Firstly, the MapReduce image processing model of Hadoop cloud platform is designed, the input and output of image are customized and the segmentation method of the data file is rewritten. Then the Mean Shift image segmentation algorithm is implemented. Finally, this paper makes a segmentation experiment on remote sensing image, and uses MATLAB to realize the Mean Shift image segmentation algorithm to compare the same image segmentation experiment. The experimental results show that under the premise of ensuring good effect, the segmentation rate of remote sensing image segmentation based on Hadoop cloud Platform has been greatly improved compared with the single MATLAB image segmentation, and there is a great improvement in the effectiveness of image segmentation.

  8. Dual sensing-actuation artificial muscle based on polypyrrole-carbon nanotube composite

    Science.gov (United States)

    Schumacher, J.; Otero, Toribio F.; Pascual, Victor H.

    2017-04-01

    Dual sensing artificial muscles based on conducting polymer are faradaic motors driven by electrochemical reactions, which announce the development of proprioceptive devices. The applicability of different composites has been investigated with the aim to improve the performance. Addition of carbon nanotubes may reduce irreversible reactions. We present the testing of a dual sensing artificial muscle based on a conducting polymer and carbon nanotubes composite. Large bending motions (up to 127 degrees) in aqueous solution and simultaneously sensing abilities of the operation conditions are recorded. The sensing and actuation equations are derived for incorporation into a control system.

  9. Three-Dimensional Inverse Transport Solver Based on Compressive Sensing Technique

    Science.gov (United States)

    Cheng, Yuxiong; Wu, Hongchun; Cao, Liangzhi; Zheng, Youqi

    2013-09-01

    According to the direct exposure measurements from flash radiographic image, a compressive sensing-based method for three-dimensional inverse transport problem is presented. The linear absorption coefficients and interface locations of objects are reconstructed directly at the same time. It is always very expensive to obtain enough measurements. With limited measurements, compressive sensing sparse reconstruction technique orthogonal matching pursuit is applied to obtain the sparse coefficients by solving an optimization problem. A three-dimensional inverse transport solver is developed based on a compressive sensing-based technique. There are three features in this solver: (1) AutoCAD is employed as a geometry preprocessor due to its powerful capacity in graphic. (2) The forward projection matrix rather than Gauss matrix is constructed by the visualization tool generator. (3) Fourier transform and Daubechies wavelet transform are adopted to convert an underdetermined system to a well-posed system in the algorithm. Simulations are performed and numerical results in pseudo-sine absorption problem, two-cube problem and two-cylinder problem when using compressive sensing-based solver agree well with the reference value.

  10. Changing implicit attitudes toward smoking: results from a web-based approach-avoidance practice intervention.

    Science.gov (United States)

    Macy, Jonathan T; Chassin, Laurie; Presson, Clark C; Sherman, Jeffrey W

    2015-02-01

    Implicit attitudes have been shown to predict smoking behaviors. Therefore, an important goal is the development of interventions to change these attitudes. This study assessed the effects of a web-based intervention on implicit attitudes toward smoking and receptivity to smoking-related information. Smokers (N = 284) were recruited to a two-session web-based study. In the first session, baseline data were collected. Session two contained the intervention, which consisted of assignment to the experimental or control version of an approach-avoidance task and assignment to an anti-smoking or control public service announcement (PSA), and post-intervention measures. Among smokers with less education and with plans to quit, implicit attitudes were more negative for those who completed the approach-avoidance task. Smokers with more education who viewed the anti-smoking PSA and completed the approach-avoidance task spent more time reading smoking-related information. An approach-avoidance task is a potentially feasible strategy for changing implicit attitudes toward smoking and increasing receptivity to smoking-related information.

  11. Surface Properties and Characteristics of Mars Landing Sites from Remote Sensing Data and Ground Truth

    Science.gov (United States)

    Golombek, M. P.; Haldemann, A. F.; Simpson, R. A.; Furgason, R. L.; Putzig, N. E.; Huertas, A.; Arvidson, R. E.; Heet, T.; Bell, J. F.; Mellon, M. T.; McEwen, A. S.

    2008-12-01

    Surface characteristics at the six sites where spacecraft have successfully landed on Mars can be related favorably to their signatures in remotely sensed data from orbit and from the Earth. Comparisons of the rock abundance, types and coverage of soils (and their physical properties), thermal inertia, albedo, and topographic slope all agree with orbital remote sensing estimates and show that the materials at the landing sites can be used as ground truth for the materials that make up most of the equatorial and mid- to moderately high-latitude regions of Mars. The six landing sites sample two of the three dominant global thermal inertia and albedo units that cover ~80% of the surface of Mars. The Viking, Spirit, Mars Pathfinder, and Phoenix landing sites are representative of the moderate to high thermal inertia and intermediate to high albedo unit that is dominated by crusty, cloddy, blocky or frozen soils (duricrust that may be layered) with various abundances of rocks and bright dust. The Opportunity landing site is representative of the moderate to high thermal inertia and low albedo surface unit that is relatively dust free and composed of dark eolian sand and/or increased abundance of rocks. Rock abundance derived from orbital thermal differencing techniques in the equatorial regions agrees with that determined from rock counts at the surface and varies from ~3-20% at the landing sites. The size-frequency distributions of rocks >1.5 m diameter fully resolvable in HiRISE images of the landing sites follow exponential models developed from lander measurements of smaller rocks and are continuous with these rock distributions indicating both are part of the same population. Interpretation of radar data confirms the presence of load bearing, relatively dense surfaces controlled by the soil type at the landing sites, regional rock populations from diffuse scattering similar to those observed directly at the sites, and root-mean-squared slopes that compare favorably

  12. Construction of three lanthanide metal-organic frameworks: Synthesis, structure, magnetic properties and highly selective sensing of metal ions

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Xiu-Mei, E-mail: zhangxiumeilb@126.com; Li, Peng; Gao, Wei; Liu, Feng; Liu, Jie-Ping

    2016-12-15

    Three lanthanide metal-organic frameworks (Ln-MOFs), [Ln(TZI)(H{sub 2}O){sub 4}]·3H{sub 2}O (Ln=Gd (1) and Tb (2) and Dy (3), H{sub 3}TZI=5-(1H-tetrazol-5-yl)isophthalic acid), have been synthesized under hydrothermal conditions. Single crystal X-ray diffraction reveals that 1–3 are isostructural and display a 1D double chain based on dinuclear motifs with (μ-COO){sub 2} double bridges. Magnetic studies indicate antiferromagnetic interactions in 1, ferromagnetic interactions in 2 and 3. Furthermore, compound 3 displays a slow relaxation behavior. Compound 2 exhibits intense characteristic green emission of Tb(III) ions in the solid state, which can be observed by the naked eye under UV light. Interestingly, 2 can selectively sense Pb{sup 2+} and Fe{sup 3+} ions through luminescence enhancement and quenching, respectively. The luminescence quenching mechanisms have been investigated in detail. The study on luminescence Ln-MOFs as a probe for sensing Pb{sup 2+} and Fe{sup 3+} ions is exceedingly rare example. - Graphical abstract: Three Ln-MOFs were successfully synthesized using a 5-(1H-tetrazol-5-yl)isophthalic acid ligand. They displays different magnetic behavior. Especially, the Dy(III) compound slow relaxation behavior. Interestingly, the Tb(III) compound can selectively sense Pb{sup 2+} and Fe{sup 3+} ions through luminescence enhancement and quenching, respectively. - Highlights: • Three Ln-MOFs with tetrazolate dicarboxylate ligand. • Dy(III) compound displays slow relaxation behavior. • The Tb(III) compound shows highly selective luminescence sensing of the Fe{sup 3+} and Pb{sup 2+} ions.

  13. Real-Time Obstacle Avoidance for Telerobotic Systems Based on Equipotential Surface

    Directory of Open Access Journals (Sweden)

    Xin Li

    2012-09-01

    Full Text Available Redundant manipulators offer a dual advantage of flexibility and dexterity and can be used in many civilian and military areas. However, operating such systems by teleoperation is challenging because of the redundancy and unstructured task environment, which result in the human operator suffering a huge burden when telemanipulator is facing the complicated obstacles. The existing methods usually use some off-line algorithms to solve the problem of obstacle avoidance. It is difficult for them to meet the requirements of real-time teleoperation in some unknown environment. This paper presents an on-line method for a telerobotic system to take advantage of redundancy to avoid obstacle, which is based on real-time sensor information. With this method, the human operator can focus attention on the end-effector operation regardless of the obstacle avoidance of other parts. The effectiveness and advantage of the method are well demonstrated by experiments.

  14. The potential of remote sensing technology for the detection and ...

    African Journals Online (AJOL)

    Internationally, a number of studies have successfully used remote sensing technology to monitor forest damage. Remote sensing technology allows for instantaneous methods of assessments whereby ground assessments would be impossible on a regular basis. This paper provides an overview of how advances in ...

  15. Comparative VOCs sensing performance for conducting polymer and porphyrin functionalized carbon nanotubes based sensors

    Science.gov (United States)

    Datta, Kunal; Rushi, Arti; Ghosh, Prasanta; Shirsat, Mahendra

    2018-05-01

    We report sensors for detection of ethyl alcohol, a prominent volatile organic compound (VOC). Single walled carbon nanotubes were selected as main sensing backbone. As efficiency of sensor is dependent upon the choice of sensing materials, the performances of conducting polymer and porphyrin based sensors were compared. Chemiresistive sensing modality was adopted to observe the performance of sensors. It has been found that porphyrin based sensor shows higher affinity towards ethyl alcohol.

  16. The possibilities of compressed sensing based migration

    KAUST Repository

    Aldawood, Ali

    2013-09-22

    Linearized waveform inversion or Least-square migration helps reduce migration artifacts caused by limited acquisition aperture, coarse sampling of sources and receivers, and low subsurface illumination. However, leastsquare migration, based on L2-norm minimization of the misfit function, tends to produce a smeared (smoothed) depiction of the true subsurface reflectivity. Assuming that the subsurface reflectivity distribution is a sparse signal, we use a compressed-sensing (Basis Pursuit) algorithm to retrieve this sparse distribution from a small number of linear measurements. We applied a compressed-sensing algorithm to image a synthetic fault model using dense and sparse acquisition geometries. Tests on synthetic data demonstrate the ability of compressed-sensing to produce highly resolved migrated images. We, also, studied the robustness of the Basis Pursuit algorithm in the presence of Gaussian random noise.

  17. The possibilities of compressed sensing based migration

    KAUST Repository

    Aldawood, Ali; Hoteit, Ibrahim; Alkhalifah, Tariq Ali

    2013-01-01

    Linearized waveform inversion or Least-square migration helps reduce migration artifacts caused by limited acquisition aperture, coarse sampling of sources and receivers, and low subsurface illumination. However, leastsquare migration, based on L2-norm minimization of the misfit function, tends to produce a smeared (smoothed) depiction of the true subsurface reflectivity. Assuming that the subsurface reflectivity distribution is a sparse signal, we use a compressed-sensing (Basis Pursuit) algorithm to retrieve this sparse distribution from a small number of linear measurements. We applied a compressed-sensing algorithm to image a synthetic fault model using dense and sparse acquisition geometries. Tests on synthetic data demonstrate the ability of compressed-sensing to produce highly resolved migrated images. We, also, studied the robustness of the Basis Pursuit algorithm in the presence of Gaussian random noise.

  18. Validating MODIS and Sentinel-2 NDVI Products at a Temperate Deciduous Forest Site Using Two Independent Ground-Based Sensors.

    Science.gov (United States)

    Lange, Maximilian; Dechant, Benjamin; Rebmann, Corinna; Vohland, Michael; Cuntz, Matthias; Doktor, Daniel

    2017-08-11

    Quantifying the accuracy of remote sensing products is a timely endeavor given the rapid increase in Earth observation missions. A validation site for Sentinel-2 products was hence established in central Germany. Automatic multispectral and hyperspectral sensor systems were installed in parallel with an existing eddy covariance flux tower, providing spectral information of the vegetation present at high temporal resolution. Normalized Difference Vegetation Index (NDVI) values from ground-based hyperspectral and multispectral sensors were compared with NDVI products derived from Sentinel-2A and Moderate-resolution Imaging Spectroradiometer (MODIS). The influence of different spatial and temporal resolutions was assessed. High correlations and similar phenological patterns between in situ and satellite-based NDVI time series demonstrated the reliability of satellite-based phenological metrics. Sentinel-2-derived metrics showed better agreement with in situ measurements than MODIS-derived metrics. Dynamic filtering with the best index slope extraction algorithm was nevertheless beneficial for Sentinel-2 NDVI time series despite the availability of quality information from the atmospheric correction procedure.

  19. Ground System Architectures Workshop GMSEC SERVICES SUITE (GSS): an Agile Development Story

    Science.gov (United States)

    Ly, Vuong

    2017-01-01

    The GMSEC (Goddard Mission Services Evolution Center) Services Suite (GSS) is a collection of tools and software services along with a robust customizable web-based portal that enables the user to capture, monitor, report, and analyze system-wide GMSEC data. Given our plug-and-play architecture and the needs for rapid system development, we opted to follow the Scrum Agile Methodology for software development. Being one of the first few projects to implement the Agile methodology at NASA GSFC, in this presentation we will present our approaches, tools, successes, and challenges in implementing this methodology. The GMSEC architecture provides a scalable, extensible ground and flight system for existing and future missions. GMSEC comes with a robust Application Programming Interface (GMSEC API) and a core set of Java-based GMSEC components that facilitate the development of a GMSEC-based ground system. Over the past few years, we have seen an upbeat in the number of customers who are moving from a native desktop application environment to a web based environment particularly for data monitoring and analysis. We also see a need to provide separation of the business logic from the GUI display for our Java-based components and also to consolidate all the GUI displays into one interface. This combination of separation and consolidation brings immediate value to a GMSEC-based ground system through increased ease of data access via a uniform interface, built-in security measures, centralized configuration management, and ease of feature extensibility.

  20. An Effective Scheduling-Based RFID Reader Collision Avoidance Model and Its Resource Allocation via Artificial Immune Network

    OpenAIRE

    Wang, Shanjin; Li, Zhonghua; He, Chunhui; Li, Jianming

    2016-01-01

    Radio frequency identification, that is, RFID, is one of important technologies in Internet of Things. Reader collision does impair the tag identification efficiency of an RFID system. Many developed methods, for example, the scheduling-based series, that are used to avoid RFID reader collision, have been developed. For scheduling-based methods, communication resources, that is, time slots, channels, and power, are optimally assigned to readers. In this case, reader collision avoidance is equ...