Kalman Filters in Geotechnical Monitoring of Ground Subsidence Using Data from MEMS Sensors

Directory of Open Access Journals (Sweden)

Cheng Li

2016-07-01

Full Text Available The fast development of wireless sensor networks and MEMS make it possible to set up today real-time wireless geotechnical monitoring. To handle interferences and noises from the output data, Kalman filter can be selected as a method to achieve a more realistic estimate of the observations. In this paper, a one-day wireless measurement using accelerometers and inclinometers was deployed on top of a tunnel section under construction in order to monitor ground subsidence. The normal vectors of the sensors were firstly obtained with the help of rotation matrices, and then be projected to the plane of longitudinal section, by which the dip angles over time would be obtained via a trigonometric function. Finally, a centralized Kalman filter was applied to estimate the tilt angles of the sensor nodes based on the data from the embedded accelerometer and the inclinometer. Comparing the results from two sensor nodes deployed away and on the track respectively, the passing of the tunnel boring machine can be identified from unusual performances. Using this method, the ground settlement due to excavation can be measured and a real-time monitoring of ground subsidence can be realized.

Kalman Filters in Geotechnical Monitoring of Ground Subsidence Using Data from MEMS Sensors.

Science.gov (United States)

Li, Cheng; Azzam, Rafig; Fernández-Steeger, Tomás M

2016-07-19

The fast development of wireless sensor networks and MEMS make it possible to set up today real-time wireless geotechnical monitoring. To handle interferences and noises from the output data, Kalman filter can be selected as a method to achieve a more realistic estimate of the observations. In this paper, a one-day wireless measurement using accelerometers and inclinometers was deployed on top of a tunnel section under construction in order to monitor ground subsidence. The normal vectors of the sensors were firstly obtained with the help of rotation matrices, and then be projected to the plane of longitudinal section, by which the dip angles over time would be obtained via a trigonometric function. Finally, a centralized Kalman filter was applied to estimate the tilt angles of the sensor nodes based on the data from the embedded accelerometer and the inclinometer. Comparing the results from two sensor nodes deployed away and on the track respectively, the passing of the tunnel boring machine can be identified from unusual performances. Using this method, the ground settlement due to excavation can be measured and a real-time monitoring of ground subsidence can be realized.

Report on the Audit of Unattended Ground Sensor Systems

Science.gov (United States)

1991-02-26

This final report on the Audit of Unattended Ground Sensor Systems is for your information and use. Comments on the draft were considered in...preparing the final report and changes have been made where appropriate. We performed the audit from February through August 1990. The objective was to

Generation of binary holograms with a Kinect sensor for a high speed color holographic display

Science.gov (United States)

Leportier, Thibault; Park, Min-Chul; Yano, Sumio; Son, Jung-Young

2017-05-01

The Kinect sensor is a device that enables to capture a real scene with a camera and a depth sensor. A virtual model of the scene can then be obtained with a point cloud representation. A complex hologram can then be computed. However, complex data cannot be used directly because display devices cannot handle amplitude and phase modulation at the same time. Binary holograms are commonly used since they present several advantages. Among the methods that were proposed to convert holograms into a binary format, the direct-binary search (DBS) not only gives the best performance, it also offers the possibility to choose the display parameters of the binary hologram differently than the original complex hologram. Since wavelength and reconstruction distance can be modified, compensation of chromatic aberrations can be handled. In this study, we examine the potential of DBS for RGB holographic display.

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

The Rover Environmental Monitoring Station Ground Temperature Sensor: A Pyrometer for Measuring Ground Temperature on Mars

Directory of Open Access Journals (Sweden)

Miguel Ramos

2010-10-01

Full Text Available We describe the parameters that drive the design and modeling of the Rover Environmental Monitoring Station (REMS Ground Temperature Sensor (GTS, an instrument aboard NASA’s Mars Science Laboratory, and report preliminary test results. REMS GTS is a lightweight, low-power, and low cost pyrometer for measuring the Martian surface kinematic temperature. The sensor’s main feature is its innovative design, based on a simple mechanical structure with no moving parts. It includes an in-flight calibration system that permits sensor recalibration when sensor sensitivity has been degraded by deposition of dust over the optics. This paper provides the first results of a GTS engineering model working in a Martian-like, extreme environment.

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.

Solid state magnetic field sensors for micro unattended ground networks using spin dependent tunneling

Science.gov (United States)

Tondra, Mark; Nordman, Catherine A.; Lange, Erik H.; Reed, Daniel; Jander, Albrect; Akou, Seraphin; Daughton, James

2001-09-01

Micro Unattended Ground Sensor Networks will likely employ magnetic sensors, primarily for discrimination of objects as opposed to initial detection. These magnetic sensors, then, must fit within very small cost, size, and power budgets to be compatible with the envisioned sensor suites. Also, a high degree of sensitivity is required to minimize the number of sensor cells required to survey a given area in the field. Solid state magnetoresistive sensors, with their low cost, small size, and ease of integration, are excellent candidates for these applications assuming that their power and sensitivity performance are acceptable. SDT devices have been fabricated into prototype magnetic field sensors suitable for use in micro unattended ground sensor networks. They are housed in tiny SOIC 8-pin packages and mounted on a circuit board with required voltage regulation, signal amplification and conditioning, and sensor control and communications functions. The best sensitivity results to date are 289 pT/rt. Hz at 1 Hz, and and 7 pT/rt. Hz at f > 10 kHz. Expected near term improvements in performance would bring these levels to approximately 10 pT/rt Hz at 1 Hz and approximately 1 pT/rt. Hz at > 1 kHz.

Design and performance of an integrated ground and space sensor web for monitoring active volcanoes.

Science.gov (United States)

Lahusen, Richard; Song, Wenzhan; Kedar, Sharon; Shirazi, Behrooz; Chien, Steve; Doubleday, Joshua; Davies, Ashley; Webb, Frank; Dzurisin, Dan; Pallister, John

2010-05-01

An interdisciplinary team of computer, earth and space scientists collaborated to develop a sensor web system for rapid deployment at active volcanoes. The primary goals of this Optimized Autonomous Space In situ Sensorweb (OASIS) are to: 1) integrate complementary space and in situ (ground-based) elements into an interactive, autonomous sensor web; 2) advance sensor web power and communication resource management technology; and 3) enable scalability for seamless addition sensors and other satellites into the sensor web. This three-year project began with a rigorous multidisciplinary interchange that resulted in definition of system requirements to guide the design of the OASIS network and to achieve the stated project goals. Based on those guidelines, we have developed fully self-contained in situ nodes that integrate GPS, seismic, infrasonic and lightning (ash) detection sensors. The nodes in the wireless sensor network are linked to the ground control center through a mesh network that is highly optimized for remote geophysical monitoring. OASIS also features an autonomous bidirectional interaction between ground nodes and instruments on the EO-1 space platform through continuous analysis and messaging capabilities at the command and control center. Data from both the in situ sensors and satellite-borne hyperspectral imaging sensors stream into a common database for real-time visualization and analysis by earth scientists. We have successfully completed a field deployment of 15 nodes within the crater and on the flanks of Mount St. Helens, Washington. The demonstration that sensor web technology facilitates rapid network deployments and that we can achieve real-time continuous data acquisition. We are now optimizing component performance and improving user interaction for additional deployments at erupting volcanoes in 2010.

Soft, smart contact lenses with integrations of wireless circuits, glucose sensors, and displays.

Science.gov (United States)

Park, Jihun; Kim, Joohee; Kim, So-Yun; Cheong, Woon Hyung; Jang, Jiuk; Park, Young-Geun; Na, Kyungmin; Kim, Yun-Tae; Heo, Jun Hyuk; Lee, Chang Young; Lee, Jung Heon; Bien, Franklin; Park, Jang-Ung

2018-01-01

Recent advances in wearable electronics combined with wireless communications are essential to the realization of medical applications through health monitoring technologies. For example, a smart contact lens, which is capable of monitoring the physiological information of the eye and tear fluid, could provide real-time, noninvasive medical diagnostics. However, previous reports concerning the smart contact lens have indicated that opaque and brittle components have been used to enable the operation of the electronic device, and this could block the user's vision and potentially damage the eye. In addition, the use of expensive and bulky equipment to measure signals from the contact lens sensors could interfere with the user's external activities. Thus, we report an unconventional approach for the fabrication of a soft, smart contact lens in which glucose sensors, wireless power transfer circuits, and display pixels to visualize sensing signals in real time are fully integrated using transparent and stretchable nanostructures. The integration of this display into the smart lens eliminates the need for additional, bulky measurement equipment. This soft, smart contact lens can be transparent, providing a clear view by matching the refractive indices of its locally patterned areas. The resulting soft, smart contact lens provides real-time, wireless operation, and there are in vivo tests to monitor the glucose concentration in tears (suitable for determining the fasting glucose level in the tears of diabetic patients) and, simultaneously, to provide sensing results through the contact lens display.

Evaluation of chemical sensors for in situ ground-water monitoring at the Hanford Site

Energy Technology Data Exchange (ETDEWEB)

Murphy, E.M.; Hostetler, D.D.

1989-03-01

This report documents a preliminary review and evaluation of instrument systems and sensors that may be used to detect ground-water contaminants in situ at the Hanford Site. Three topics are covered in this report: (1) identification of a group of priority contaminants at Hanford that could be monitored in situ, (2) a review of current instrument systems and sensors for environmental monitoring, and (3) an evaluation of instrument systems that could be used to monitor Hanford contaminants. Thirteen priority contaminants were identified in Hanford ground water, including carbon tetrachloride and six related chlorinated hydrocarbons, cyanide, methyl ethyl ketone, chromium (VI), fluoride, nitrate, and uranium. Based on transduction principles, chemical sensors were divided into four classes, ten specific types of instrument systems were considered: fluorescence spectroscopy, surface-enhanced Raman spectroscopy (SERS), spark excitation-fiber optic spectrochemical emission sensor (FOSES), chemical optrodes, stripping voltammetry, catalytic surface-modified ion electrode immunoassay sensors, resistance/capacitance, quartz piezobalance and surface acoustic wave devices. Because the flow of heat is difficult to control, there are currently no environmental chemical sensors based on thermal transduction. The ability of these ten instrument systems to detect the thirteen priority contaminants at the Hanford Site at the required sensitivity was evaluated. In addition, all ten instrument systems were qualitatively evaluated for general selectivity, response time, reliability, and field operability. 45 refs., 23 figs., 7 tabs.

Evaluation of chemical sensors for in situ ground-water monitoring at the Hanford Site

International Nuclear Information System (INIS)

Murphy, E.M.; Hostetler, D.D.

1989-03-01

This report documents a preliminary review and evaluation of instrument systems and sensors that may be used to detect ground-water contaminants in situ at the Hanford Site. Three topics are covered in this report: (1) identification of a group of priority contaminants at Hanford that could be monitored in situ, (2) a review of current instrument systems and sensors for environmental monitoring, and (3) an evaluation of instrument systems that could be used to monitor Hanford contaminants. Thirteen priority contaminants were identified in Hanford ground water, including carbon tetrachloride and six related chlorinated hydrocarbons, cyanide, methyl ethyl ketone, chromium (VI), fluoride, nitrate, and uranium. Based on transduction principles, chemical sensors were divided into four classes, ten specific types of instrument systems were considered: fluorescence spectroscopy, surface-enhanced Raman spectroscopy (SERS), spark excitation-fiber optic spectrochemical emission sensor (FOSES), chemical optrodes, stripping voltammetry, catalytic surface-modified ion electrode immunoassay sensors, resistance/capacitance, quartz piezobalance and surface acoustic wave devices. Because the flow of heat is difficult to control, there are currently no environmental chemical sensors based on thermal transduction. The ability of these ten instrument systems to detect the thirteen priority contaminants at the Hanford Site at the required sensitivity was evaluated. In addition, all ten instrument systems were qualitatively evaluated for general selectivity, response time, reliability, and field operability. 45 refs., 23 figs., 7 tabs

Development of mine explosion ground truth smart sensors

Energy Technology Data Exchange (ETDEWEB)

Taylor, Steven R. [Rocky Mountain Geophysics, Inc., Los Alamos, NM (United States); Harben, Phillip E. [Rocky Mountain Geophysics, Inc., Los Alamos, NM (United States); Jarpe, Steve [Jarpe Data Solutions, Prescott, AZ (United States); Harris, David B. [Deschutes Signal Processing, Maupin, OR (United States)

2015-09-14

Accurate seismo-acoustic source location is one of the fundamental aspects of nuclear explosion monitoring. Critical to improved location is the compilation of ground truth data sets for which origin time and location are accurately known. Substantial effort by the National Laboratories and other seismic monitoring groups have been undertaken to acquire and develop ground truth catalogs that form the basis of location efforts (e.g. Sweeney, 1998; Bergmann et al., 2009; Waldhauser and Richards, 2004). In particular, more GT1 (Ground Truth 1 km) events are required to improve three-dimensional velocity models that are currently under development. Mine seismicity can form the basis of accurate ground truth datasets. Although the location of mining explosions can often be accurately determined using array methods (e.g. Harris, 1991) and from overhead observations (e.g. MacCarthy et al., 2008), accurate origin time estimation can be difficult. Occasionally, mine operators will share shot time, location, explosion size and even shot configuration, but this is rarely done, especially in foreign countries. Additionally, shot times provided by mine operators are often inaccurate. An inexpensive, ground truth event detector that could be mailed to a contact, placed in close proximity (< 5 km) to mining regions or earthquake aftershock regions that automatically transmits back ground-truth parameters, would greatly aid in development of ground truth datasets that could be used to improve nuclear explosion monitoring capabilities. We are developing an inexpensive, compact, lightweight smart sensor unit (or units) that could be used in the development of ground truth datasets for the purpose of improving nuclear explosion monitoring capabilities. The units must be easy to deploy, be able to operate autonomously for a significant period of time (> 6 months) and inexpensive enough to be discarded after useful operations have expired (although this may not be part of our business

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...

Development of an optochemical sensor for continuous reversible determination of nitrate in drinking water and ground water

International Nuclear Information System (INIS)

Lumpp, R.

1993-09-01

An optochemical sensor has been developed for continuous reversible determination of nitrate in drinking water and ground water. The sensor is based on the combination of the anion selective liquid ion exchanger Ni(II[bathophenanthroline] 3 2+ with phenolsulfonephtalein dyes in a polyvinylchloride membrane. (orig.) [de

Disposable Multi-Sensor Unattended Ground Sensor Systems for Detecting Personnel (Systemes de detection multi-capteurs terrestres autonome destines a detecter du personnel)

Science.gov (United States)

2015-02-01

the set of DCT coefficients for all the training data corresponding to the people. Then, the matrix ][ pX can be written as: ][][][ −+ −= ppp XXX ...deployed on two types of ground conditions. This included ARL multi-modal sensors, video and acoustic sensors from the Universities of Memphis and...Mississippi, SASNet from Canada, video from Night Vision Laboratory and Pearls of Wisdom system from Israel operated in conjunction with ARL personnel. This

Proposed evaluation framework for assessing operator performance with multisensor displays

Science.gov (United States)

Foyle, David C.

1992-01-01

Despite aggressive work on the development of sensor fusion algorithms and techniques, no formal evaluation procedures have been proposed. Based on existing integration models in the literature, an evaluation framework is developed to assess an operator's ability to use multisensor, or sensor fusion, displays. The proposed evaluation framework for evaluating the operator's ability to use such systems is a normative approach: The operator's performance with the sensor fusion display can be compared to the models' predictions based on the operator's performance when viewing the original sensor displays prior to fusion. This allows for the determination as to when a sensor fusion system leads to: 1) poorer performance than one of the original sensor displays (clearly an undesirable system in which the fused sensor system causes some distortion or interference); 2) better performance than with either single sensor system alone, but at a sub-optimal (compared to the model predictions) level; 3) optimal performance (compared to model predictions); or, 4) super-optimal performance, which may occur if the operator were able to use some highly diagnostic 'emergent features' in the sensor fusion display, which were unavailable in the original sensor displays. An experiment demonstrating the usefulness of the proposed evaluation framework is discussed.

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.

Toward High Altitude Airship Ground-Based Boresight Calibration of Hyperspectral Pushbroom Imaging Sensors

Directory of Open Access Journals (Sweden)

Aiwu Zhang

2015-12-01

Full Text Available The complexity of the single linear hyperspectral pushbroom imaging based on a high altitude airship (HAA without a three-axis stabilized platform is much more than that based on the spaceborne and airborne. Due to the effects of air pressure, temperature and airflow, the large pitch and roll angles tend to appear frequently that create pushbroom images highly characterized with severe geometric distortions. Thus, the in-flight calibration procedure is not appropriate to apply to the single linear pushbroom sensors on HAA having no three-axis stabilized platform. In order to address this problem, a new ground-based boresight calibration method is proposed. Firstly, a coordinate’s transformation model is developed for direct georeferencing (DG of the linear imaging sensor, and then the linear error equation is derived from it by using the Taylor expansion formula. Secondly, the boresight misalignments are worked out by using iterative least squares method with few ground control points (GCPs and ground-based side-scanning experiments. The proposed method is demonstrated by three sets of experiments: (i the stability and reliability of the method is verified through simulation-based experiments; (ii the boresight calibration is performed using ground-based experiments; and (iii the validation is done by applying on the orthorectification of the real hyperspectral pushbroom images from a HAA Earth observation payload system developed by our research team—“LanTianHao”. The test results show that the proposed boresight calibration approach significantly improves the quality of georeferencing by reducing the geometric distortions caused by boresight misalignments to the minimum level.

Estimation of ground reaction forces and joint moments on the basis on plantar pressure insoles and wearable sensors for joint angle measurement.

Science.gov (United States)

Ostaszewski, Michal; Pauk, Jolanta

2018-05-16

Gait analysis is a useful tool medical staff use to support clinical decision making. There is still an urgent need to develop low-cost and unobtrusive mobile health monitoring systems. The goal of this study was twofold. Firstly, a wearable sensor system composed of plantar pressure insoles and wearable sensors for joint angle measurement was developed. Secondly, the accuracy of the system in the measurement of ground reaction forces and joint moments was examined. The measurements included joint angles and plantar pressure distribution. To validate the wearable sensor system and examine the effectiveness of the proposed method for gait analysis, an experimental study on ten volunteer subjects was conducted. The accuracy of measurement of ground reaction forces and joint moments was validated against the results obtained from a reference motion capture system. Ground reaction forces and joint moments measured by the wearable sensor system showed a root mean square error of 1% for min. GRF and 27.3% for knee extension moment. The correlation coefficient was over 0.9, in comparison with the stationary motion capture system. The study suggests that the wearable sensor system could be recommended both for research and clinical applications outside a typical gait laboratory.

Nighttime Infrared radiative cooling and opacity inferred by REMS Ground Temperature Sensor Measurements

Science.gov (United States)

Martín-Torres, Javier; Paz Zorzano, María; Pla-García, Jorge; Rafkin, Scot; Lepinette, Alain; Sebastián, Eduardo; Gómez-Elvira, Javier; REMS Team

2013-04-01

Due to the low density of the Martian atmosphere, the temperature of the surface is controlled primarily by solar heating, and infrared cooling to the atmosphere and space, rather than heat exchange with the atmosphere. In the absence of solar radiation the infrared (IR) cooling, and then the nighttime surface temperatures, are directly controlled by soil termal inertia and atmospheric optical thickness (τ) at infrared wavelengths. Under non-wind conditions, and assuming no processes involving latent heat changes in the surface, for a particular site where the rover stands the main parameter controlling the IR cooling will be τ. The minimal ground temperature values at a fixed position may thus be used to detect local variations in the total dust/aerosols/cloud tickness. The Ground Temperature Sensor (GTS) and Air Temperature Sensor (ATS) in the Rover Environmental Monitoring Station (REMS) on board the Mars Science Laboratory (MSL) Curiosity rover provides hourly ground and air temperature measurements respectively. During the first 100 sols of operation of the rover, within the area of low thermal inertia, the minimal nightime ground temperatures reached values between 180 K and 190 K. For this season the expected frost point temperature is 200 K. Variations of up to 10 K have been observed associated with dust loading at Gale at the onset of the dust season. We will use these measurements together with line-by-line radiative transfer simulations using the Full Transfer By Optimized LINe-by-line (FUTBOLIN) code [Martín-Torres and Mlynczak, 2005] to estimate the IR atmospheric opacity and then dust/cloud coverage over the rover during the course of the MSL mission. Monitoring the dust loading and IR nightime cooling evolution during the dust season will allow for a better understanding of the influence of the atmosphere on the ground temperature and provide ground truth to models and orbiter measurements. References Martín-Torres, F. J. and M. G. Mlynczak

Forecasting Global Horizontal Irradiance Using the LETKF and a Combination of Advected Satellite Images and Sparse Ground Sensors

Science.gov (United States)

Harty, T. M.; Lorenzo, A.; Holmgren, W.; Morzfeld, M.

2017-12-01

The irradiance incident on a solar panel is the main factor in determining the power output of that panel. For this reason, accurate global horizontal irradiance (GHI) estimates and forecasts are critical when determining the optimal location for a solar power plant, forecasting utility scale solar power production, or forecasting distributed, behind the meter rooftop solar power production. Satellite images provide a basis for producing the GHI estimates needed to undertake these objectives. The focus of this work is to combine satellite derived GHI estimates with ground sensor measurements and an advection model. The idea is to use accurate but sparsely distributed ground sensors to improve satellite derived GHI estimates which can cover large areas (the size of a city or a region of the United States). We use a Bayesian framework to perform the data assimilation, which enables us to produce irradiance forecasts and associated uncertainties which incorporate both satellite and ground sensor data. Within this framework, we utilize satellite images taken from the GOES-15 geostationary satellite (available every 15-30 minutes) as well as ground data taken from irradiance sensors and rooftop solar arrays (available every 5 minutes). The advection model, driven by wind forecasts from a numerical weather model, simulates cloud motion between measurements. We use the Local Ensemble Transform Kalman Filter (LETKF) to perform the data assimilation. We present preliminary results towards making such a system useful in an operational context. We explain how localization and inflation in the LETKF, perturbations of wind-fields, and random perturbations of the advection model, affect the accuracy of our estimates and forecasts. We present experiments showing the accuracy of our forecasted GHI over forecast-horizons of 15 mins to 1 hr. The limitations of our approach and future improvements are also discussed.

Transparent Fingerprint Sensor System for Large Flat Panel Display.

Science.gov (United States)

Seo, Wonkuk; Pi, Jae-Eun; Cho, Sung Haeung; Kang, Seung-Youl; Ahn, Seong-Deok; Hwang, Chi-Sun; Jeon, Ho-Sik; Kim, Jong-Uk; Lee, Myunghee

2018-01-19

In this paper, we introduce a transparent fingerprint sensing system using a thin film transistor (TFT) sensor panel, based on a self-capacitive sensing scheme. An armorphousindium gallium zinc oxide (a-IGZO) TFT sensor array and associated custom Read-Out IC (ROIC) are implemented for the system. The sensor panel has a 200 × 200 pixel array and each pixel size is as small as 50 μm × 50 μm. The ROIC uses only eight analog front-end (AFE) amplifier stages along with a successive approximation analog-to-digital converter (SAR ADC). To get the fingerprint image data from the sensor array, the ROIC senses a capacitance, which is formed by a cover glass material between a human finger and an electrode of each pixel of the sensor array. Three methods are reviewed for estimating the self-capacitance. The measurement result demonstrates that the transparent fingerprint sensor system has an ability to differentiate a human finger's ridges and valleys through the fingerprint sensor array.

Transparent Fingerprint Sensor System for Large Flat Panel Display

Directory of Open Access Journals (Sweden)

Wonkuk Seo

2018-01-01

Full Text Available In this paper, we introduce a transparent fingerprint sensing system using a thin film transistor (TFT sensor panel, based on a self-capacitive sensing scheme. An armorphousindium gallium zinc oxide (a-IGZO TFT sensor array and associated custom Read-Out IC (ROIC are implemented for the system. The sensor panel has a 200 × 200 pixel array and each pixel size is as small as 50 μm × 50 μm. The ROIC uses only eight analog front-end (AFE amplifier stages along with a successive approximation analog-to-digital converter (SAR ADC. To get the fingerprint image data from the sensor array, the ROIC senses a capacitance, which is formed by a cover glass material between a human finger and an electrode of each pixel of the sensor array. Three methods are reviewed for estimating the self-capacitance. The measurement result demonstrates that the transparent fingerprint sensor system has an ability to differentiate a human finger’s ridges and valleys through the fingerprint sensor array.

Estimation of Vertical Ground Reaction Forces and Sagittal Knee Kinematics During Running Using Three Inertial Sensors

Directory of Open Access Journals (Sweden)

Frank J. Wouda

2018-03-01

Full Text Available Analysis of running mechanics has traditionally been limited to a gait laboratory using either force plates or an instrumented treadmill in combination with a full-body optical motion capture system. With the introduction of inertial motion capture systems, it becomes possible to measure kinematics in any environment. However, kinetic information could not be provided with such technology. Furthermore, numerous body-worn sensors are required for a full-body motion analysis. The aim of this study is to examine the validity of a method to estimate sagittal knee joint angles and vertical ground reaction forces during running using an ambulatory minimal body-worn sensor setup. Two concatenated artificial neural networks were trained (using data from eight healthy subjects to estimate the kinematics and kinetics of the runners. The first artificial neural network maps the information (orientation and acceleration of three inertial sensors (placed at the lower legs and pelvis to lower-body joint angles. The estimated joint angles in combination with measured vertical accelerations are input to a second artificial neural network that estimates vertical ground reaction forces. To validate our approach, estimated joint angles were compared to both inertial and optical references, while kinetic output was compared to measured vertical ground reaction forces from an instrumented treadmill. Performance was evaluated using two scenarios: training and evaluating on a single subject and training on multiple subjects and evaluating on a different subject. The estimated kinematics and kinetics of most subjects show excellent agreement (ρ>0.99 with the reference, for single subject training. Knee flexion/extension angles are estimated with a mean RMSE <5°. Ground reaction forces are estimated with a mean RMSE < 0.27 BW. Additionaly, peak vertical ground reaction force, loading rate and maximal knee flexion during stance were compared, however, no significant

Mobile Ground-Based Radar Sensor for Localization and Mapping: An Evaluation of two Approaches

Directory of Open Access Journals (Sweden)

Damien Vivet

2013-08-01

Full Text Available This paper is concerned with robotic applications using a ground-based radar sensor for simultaneous localization and mapping problems. In mobile robotics, radar technology is interesting because of its long range and the robustness of radar waves to atmospheric conditions, making these sensors well-suited for extended outdoor robotic applications. Two localization and mapping approaches using data obtained from a 360° field of view microwave radar sensor are presented and compared. The first method is a trajectory-oriented simultaneous localization and mapping technique, which makes no landmark assumptions and avoids the data association problem. The estimation of the ego-motion makes use of the Fourier-Mellin transform for registering radar images in a sequence, from which the rotation and translation of the sensor motion can be estimated. The second approach uses the consequence of using a rotating range sensor in high speed robotics. In such a situation, movement combinations create distortions in the collected data. Velocimetry is achieved here by explicitly analysing these measurement distortions. As a result, the trajectory of the vehicle and then the radar map of outdoor environments can be obtained. The evaluation of experimental results obtained by the two methods is presented on real-world data from a vehicle moving at 30 km/h over a 2.5 km course.

Design of smart home sensor visualizations for older adults.

Science.gov (United States)

Le, Thai; Reeder, Blaine; Chung, Jane; Thompson, Hilaire; Demiris, George

2014-07-24

Smart home sensor systems provide a valuable opportunity to continuously and unobtrusively monitor older adult wellness. However, the density of sensor data can be challenging to visualize, especially for an older adult consumer with distinct user needs. We describe the design of sensor visualizations informed by interviews with older adults. The goal of the visualizations is to present sensor activity data to an older adult consumer audience that supports both longitudinal detection of trends and on-demand display of activity details for any chosen day. The design process is grounded through participatory design with older adult interviews during a six-month pilot sensor study. Through a secondary analysis of interviews, we identified the visualization needs of older adults. We incorporated these needs with cognitive perceptual visualization guidelines and the emotional design principles of Norman to develop sensor visualizations. We present a design of sensor visualization that integrate both temporal and spatial components of information. The visualization supports longitudinal detection of trends while allowing the viewer to view activity within a specific date.CONCLUSIONS: Appropriately designed visualizations for older adults not only provide insight into health and wellness, but also are a valuable resource to promote engagement within care.

Design of smart home sensor visualizations for older adults.

Science.gov (United States)

Le, Thai; Reeder, Blaine; Chung, Jane; Thompson, Hilaire; Demiris, George

2014-01-01

Smart home sensor systems provide a valuable opportunity to continuously and unobtrusively monitor older adult wellness. However, the density of sensor data can be challenging to visualize, especially for an older adult consumer with distinct user needs. We describe the design of sensor visualizations informed by interviews with older adults. The goal of the visualizations is to present sensor activity data to an older adult consumer audience that supports both longitudinal detection of trends and on-demand display of activity details for any chosen day. The design process is grounded through participatory design with older adult interviews during a six-month pilot sensor study. Through a secondary analysis of interviews, we identified the visualization needs of older adults. We incorporated these needs with cognitive perceptual visualization guidelines and the emotional design principles of Norman to develop sensor visualizations. We present a design of sensor visualization that integrate both temporal and spatial components of information. The visualization supports longitudinal detection of trends while allowing the viewer to view activity within a specific date. Appropriately designed visualizations for older adults not only provide insight into health and wellness, but also are a valuable resource to promote engagement within care.

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.

Obstacle negotiation control for a mobile robot suspended on overhead ground wires by optoelectronic sensors

Science.gov (United States)

Zheng, Li; Yi, Ruan

2009-11-01

Power line inspection and maintenance already benefit from developments in mobile robotics. This paper presents mobile robots capable of crossing obstacles on overhead ground wires. A teleoperated robot realizes inspection and maintenance tasks on power transmission line equipment. The inspection robot is driven by 11 motor with two arms, two wheels and two claws. The inspection robot is designed to realize the function of observation, grasp, walk, rolling, turn, rise, and decline. This paper is oriented toward 100% reliable obstacle detection and identification, and sensor fusion to increase the autonomy level. An embedded computer based on PC/104 bus is chosen as the core of control system. Visible light camera and thermal infrared Camera are both installed in a programmable pan-and-tilt camera (PPTC) unit. High-quality visual feedback rapidly becomes crucial for human-in-the-loop control and effective teleoperation. The communication system between the robot and the ground station is based on Mesh wireless networks by 700 MHz bands. An expert system programmed with Visual C++ is developed to implement the automatic control. Optoelectronic laser sensors and laser range scanner were installed in robot for obstacle-navigation control to grasp the overhead ground wires. A novel prototype with careful considerations on mobility was designed to inspect the 500KV power transmission lines. Results of experiments demonstrate that the robot can be applied to execute the navigation and inspection tasks.

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.

Attention Sensor

NARCIS (Netherlands)

Börner, Dirk; Kalz, Marco; Specht, Marcus

2014-01-01

This software sketch was used in the context of an experiment for the PhD project “Ambient Learning Displays”. The sketch comprises a custom-built attention sensor. The sensor measured (during the experiment) whether a participant looked at and thus attended a public display. The sensor was built

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...

Tracking and Interception of Ground-Based RF Sources Using Autonomous Guided Munitions with Passive Bearings-Only Sensors and Tracking Algorithms

National Research Council Canada - National Science Library

Ezal, Kenan; Agate, Craig

2006-01-01

This paper considers the problem of tracking and intercepting a potentially moving ground-based RF source with an autonomous guided munition that has a passive bearings-only sensor located on its nose...

A low-noise MEMS accelerometer for unattended ground sensor applications

Science.gov (United States)

Speller, Kevin E.; Yu, Duli

2004-09-01

A low-noise micro-machined servo accelerometer has been developed for use in Unattended Ground Sensors (UGS). Compared to conventional coil-and-magnet based velocity transducers, this Micro-Electro-Mechanical System (MEMS) accelerometer offers several key benefits for battlefield monitoring. Many UGS require a compass to determine deployment orientation with respect to magnetic North. This orientation information is critical for determining the bearing of incoming signals. Conventional sensors with sensing technology based on a permanent magnet can cause interference with a compass when used in close proximity. This problem is solved with a MEMS accelerometer which does not require any magnetic materials. Frequency information below 10 Hz is valuable for identification of signal sources. Conventional seismometers used in UGS are typically limited in frequency response from 20 to 200 Hz. The MEMS accelerometer has a flat frequency response from DC to 5 kHz. The wider spectrum of signals received improves detection, classification and monitoring on the battlefield. The DC-coupled output of the MEMS accelerometer also has the added benefit of providing tilt orientation data for the deployed UGS. Other performance parameters of the MEMS accelerometer that are important to UGS such as size, weight, shock survivability, phase response, distortion, and cross-axis rejection will be discussed. Additionally, field test data from human footsteps recorded with the MEMS accelerometer will be presented.

Evaluation of event-based algorithms for optical flow with ground-truth from inertial measurement sensor

Directory of Open Access Journals (Sweden)

Bodo eRückauer

2016-04-01

Full Text Available In this study we compare nine optical flow algorithms that locally measure the flow normal to edges according to accuracy and computation cost. In contrast to conventional, frame-based motion flow algorithms, our open-source implementations compute optical flow based on address-events from a neuromorphic Dynamic Vision Sensor (DVS. For this benchmarking we created a dataset of two synthesized and three real samples recorded from a 240x180 pixel Dynamic and Active-pixel Vision Sensor (DAVIS. This dataset contains events from the DVS as well as conventional frames to support testing state-of-the-art frame-based methods. We introduce a new source for the ground truth: In the special case that the perceived motion stems solely from a rotation of the vision sensor around its three camera axes, the true optical flow can be estimated using gyro data from the inertial measurement unit integrated with the DAVIS camera. This provides a ground-truth to which we can compare algorithms that measure optical flow by means of motion cues. An analysis of error sources led to the use of a refractory period, more accurate numerical derivatives and a Savitzky-Golay filter to achieve significant improvements in accuracy. Our pure Java implementations of two recently published algorithms reduce computational cost by up to 29% compared to the original implementations. Two of the algorithms introduced in this paper further speed up processing by a factor of 10 compared with the original implementations, at equal or better accuracy. On a desktop PC, they run in real-time on dense natural input recorded by a DAVIS camera.

Optical Communication System for Remote Monitoring and Adaptive Control of Distributed Ground Sensors Exhibiting Collective Intelligence

Energy Technology Data Exchange (ETDEWEB)

Cameron, S.M.; Stantz, K.M.; Trahan, M.W.; Wagner, J.S.

1998-11-01

Comprehensive management of the battle-space has created new requirements in information management, communication, and interoperability as they effect surveillance and situational awareness. The objective of this proposal is to expand intelligent controls theory to produce a uniquely powerful implementation of distributed ground-based measurement incorporating both local collective behavior, and interoperative global optimization for sensor fusion and mission oversight. By using a layered hierarchal control architecture to orchestrate adaptive reconfiguration of autonomous robotic agents, we can improve overall robustness and functionality in dynamic tactical environments without information bottlenecks. In this concept, each sensor is equipped with a miniaturized optical reflectance modulator which is interactively monitored as a remote transponder using a covert laser communication protocol from a remote mothership or operative. Robot data-sharing at the ground level can be leveraged with global evaluation criteria, including terrain overlays and remote imaging data. Information sharing and distributed intelli- gence opens up a new class of remote-sensing applications in which small single-function autono- mous observers at the local level can collectively optimize and measure large scale ground-level signals. AS the need for coverage and the number of agents grows to improve spatial resolution, cooperative behavior orchestrated by a global situational awareness umbrella will be an essential ingredient to offset increasing bandwidth requirements within the net. A system of the type described in this proposal will be capable of sensitively detecting, tracking, and mapping spatial distributions of measurement signatures which are non-stationary or obscured by clutter and inter- fering obstacles by virtue of adaptive reconfiguration. This methodology could be used, for example, to field an adaptive ground-penetrating radar for detection of underground structures in

On-irrigator pasture soil moisture sensor

International Nuclear Information System (INIS)

Tan, Adrian Eng-Choon; Richards, Sean; Platt, Ian; Woodhead, Ian

2017-01-01

In this paper, we presented the development of a proximal soil moisture sensor that measured the soil moisture content of dairy pasture directly from the boom of an irrigator. The proposed sensor was capable of soil moisture measurements at an accuracy of  ±5% volumetric moisture content, and at meter scale ground area resolutions. The sensor adopted techniques from the ultra-wideband radar to enable measurements of ground reflection at resolutions that are smaller than the antenna beamwidth of the sensor. An experimental prototype was developed for field measurements. Extensive field measurements using the developed prototype were conducted on grass pasture at different ground conditions to validate the accuracy of the sensor in performing soil moisture measurements. (paper)

Digital Image Processing Overview For Helmet Mounted Displays

Science.gov (United States)

Parise, Michael J.

1989-09-01

Digital image processing provides a means to manipulate an image and presents a user with a variety of display formats that are not available in the analog image processing environment. When performed in real time and presented on a Helmet Mounted Display, system capability and flexibility are greatly enhanced. The information content of a display can be increased by the addition of real time insets and static windows from secondary sensor sources, near real time 3-D imaging from a single sensor can be achieved, graphical information can be added, and enhancement techniques can be employed. Such increased functionality is generating a considerable amount of interest in the military and commercial markets. This paper discusses some of these image processing techniques and their applications.

Development of Mine Explosion Ground Truth Smart Sensors

Science.gov (United States)

2011-09-01

interest. The two candidates are the GS11-D by Oyo Geospace that is used extensively in seismic monitoring of geothermal fields and the Sensor Nederland SM...Technologies 853 Figure 4. Our preferred sensors and processor for the GTMS. (a) Sensor Nederland SM-6 geophone with emplacement spike. (b

Reconfigurable Auditory-Visual Display

Science.gov (United States)

Begault, Durand R. (Inventor); Anderson, Mark R. (Inventor); McClain, Bryan (Inventor); Miller, Joel D. (Inventor)

2008-01-01

System and method for visual and audible communication between a central operator and N mobile communicators (N greater than or equal to 2), including an operator transceiver and interface, configured to receive and display, for the operator, visually perceptible and audibly perceptible signals from each of the mobile communicators. The interface (1) presents an audible signal from each communicator as if the audible signal is received from a different location relative to the operator and (2) allows the operator to select, to assign priority to, and to display, the visual signals and the audible signals received from a specified communicator. Each communicator has an associated signal transmitter that is configured to transmit at least one of the visual signals and the audio signal associated with the communicator, where at least one of the signal transmitters includes at least one sensor that senses and transmits a sensor value representing a selected environmental or physiological parameter associated with the communicator.

Water-Cut Sensor System

KAUST Repository

Karimi, Muhammad Akram

2018-01-11

Provided in some embodiments is a method of manufacturing a pipe conformable water-cut sensors system. Provided in some embodiments is method for manufacturing a water-cut sensor system that includes providing a helical T-resonator, a helical ground conductor, and a separator at an exterior of a cylindrical pipe. The helical T-resonator including a feed line, and a helical open shunt stub conductively coupled to the feed line. The helical ground conductor including a helical ground plane opposite the helical open shunt stub and a ground ring conductively coupled to the helical ground plane. The feed line overlapping at least a portion of the ground ring, and the separator disposed between the feed line and the portion of the ground ring overlapped by the feed line to electrically isolate the helical T-resonator from the helical ground conductor.

Role of computer graphics in space telerobotics - Preview and predictive displays

Science.gov (United States)

Bejczy, Antal K.; Venema, Steven; Kim, Won S.

1991-01-01

The application of computer graphics in space telerobotics research and development work is briefly reviewed and illustrated by specific examples implemented in real time operation. The applications are discussed under the following four major categories: preview displays, predictive displays, sensor data displays, and control system status displays.

Integrated active fire retrievals and biomass burning emissions using complementary near-coincident ground, airborne and spaceborne sensor data

Science.gov (United States)

Wilfrid Schroeder; Evan Ellicott; Charles Ichoku; Luke Ellison; Matthew B. Dickinson; Roger D. Ottmar; Craig Clements; Dianne Hall; Vincent Ambrosia; Robert. Kremens

2013-01-01

Ground, airborne and spaceborne data were collected for a 450 ha prescribed fire implemented on 18 October 2011 at the Henry W. Coe State Park in California. The integration of various data elements allowed near-coincident active fire retrievals to be estimated. The Autonomous Modular Sensor-Wildfire (AMS) airborne multispectral imaging system was used as a bridge...

Three-Dimensional Sensor Common Operating Picture (3-D Sensor COP)

Science.gov (United States)

2017-01-01

DEMs that have been computed from the point clouds . Additionally, Fusion3D can also display 3-D data created using photogrammetry software...Picture (3-D Sensor COP). To test the 3-D Sensor COP, we took advantage of a sensor network that had been deployed for the Enterprise Challenge 2016 at...took advantage of a sensor network that had been deployed for the Enterprise Challenge 2016 (EC16) at Fort Huachuca in Sierra Vista, Arizona. The

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.

Display technologies for augmented reality

Science.gov (United States)

Lee, Byoungho; Lee, Seungjae; Jang, Changwon; Hong, Jong-Young; Li, Gang

2018-02-01

With the virtue of rapid progress in optics, sensors, and computer science, we are witnessing that commercial products or prototypes for augmented reality (AR) are penetrating into the consumer markets. AR is spotlighted as expected to provide much more immersive and realistic experience than ordinary displays. However, there are several barriers to be overcome for successful commercialization of AR. Here, we explore challenging and important topics for AR such as image combiners, enhancement of display performance, and focus cue reproduction. Image combiners are essential to integrate virtual images with real-world. Display performance (e.g. field of view and resolution) is important for more immersive experience and focus cue reproduction may mitigate visual fatigue caused by vergence-accommodation conflict. We also demonstrate emerging technologies to overcome these issues: index-matched anisotropic crystal lens (IMACL), retinal projection displays, and 3D display with focus cues. For image combiners, a novel optical element called IMACL provides relatively wide field of view. Retinal projection displays may enhance field of view and resolution of AR displays. Focus cues could be reconstructed via multi-layer displays and holographic displays. Experimental results of our prototypes are explained.

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.

Distributed cluster management techniques for unattended ground sensor networks

Science.gov (United States)

Essawy, Magdi A.; Stelzig, Chad A.; Bevington, James E.; Minor, Sharon

2005-05-01

Smart Sensor Networks are becoming important target detection and tracking tools. The challenging problems in such networks include the sensor fusion, data management and communication schemes. This work discusses techniques used to distribute sensor management and multi-target tracking responsibilities across an ad hoc, self-healing cluster of sensor nodes. Although miniaturized computing resources possess the ability to host complex tracking and data fusion algorithms, there still exist inherent bandwidth constraints on the RF channel. Therefore, special attention is placed on the reduction of node-to-node communications within the cluster by minimizing unsolicited messaging, and distributing the sensor fusion and tracking tasks onto local portions of the network. Several challenging problems are addressed in this work including track initialization and conflict resolution, track ownership handling, and communication control optimization. Emphasis is also placed on increasing the overall robustness of the sensor cluster through independent decision capabilities on all sensor nodes. Track initiation is performed using collaborative sensing within a neighborhood of sensor nodes, allowing each node to independently determine if initial track ownership should be assumed. This autonomous track initiation prevents the formation of duplicate tracks while eliminating the need for a central "management" node to assign tracking responsibilities. Track update is performed as an ownership node requests sensor reports from neighboring nodes based on track error covariance and the neighboring nodes geo-positional location. Track ownership is periodically recomputed using propagated track states to determine which sensing node provides the desired coverage characteristics. High fidelity multi-target simulation results are presented, indicating the distribution of sensor management and tracking capabilities to not only reduce communication bandwidth consumption, but to also

Simulation of olive grove gross primary production by the combination of ground and multi-sensor satellite data

Science.gov (United States)

Brilli, L.; Chiesi, M.; Maselli, F.; Moriondo, M.; Gioli, B.; Toscano, P.; Zaldei, A.; Bindi, M.

2013-08-01

We developed and tested a methodology to estimate olive (Olea europaea L.) gross primary production (GPP) combining ground and multi-sensor satellite data. An eddy-covariance station placed in an olive grove in central Italy provided carbon and water fluxes over two years (2010-2011), which were used as reference to evaluate the performance of a GPP estimation methodology based on a Monteith type model (modified C-Fix) and driven by meteorological and satellite (NDVI) data. A major issue was related to the consideration of the two main olive grove components, i.e. olive trees and inter-tree ground vegetation: this issue was addressed by the separate simulation of carbon fluxes within the two ecosystem layers, followed by their recombination. In this way the eddy covariance GPP measurements were successfully reproduced, with the exception of two periods that followed tillage operations. For these periods measured GPP could be approximated by considering synthetic NDVI values which simulated the expected response of inter-tree ground vegetation to tillages.

Measuring Radiant Emissions from Entire Prescribed Fires with Ground, Airborne and Satellite Sensors RxCADRE 2012

Science.gov (United States)

Dickinson, Matthew B.; Hudak, Andrew T.; Zajkowski, Thomas; Loudermilk, E. Louise; Schroeder, Wilfrid; Ellison, Luke; Kremens, Robert L.; Holley, William; Martinez, Otto; Paxton, Alexander;

Data displays for multi-detector monitoring systems

International Nuclear Information System (INIS)

Barnes, R.C.M.

1978-03-01

Extensive installations of sensors are used for environmental surveillance of radiological hazards, fire, etc. The data from such arrays of detectors can be collected by data processing systems which generate appropriate supervisory displays and records. This paper reviews facilities and physical configurations of computer-based display systems, with particular reference to radiological protection schemes. The general principles are relevant to other fields of application. (author)

A Smart Spoofing Face Detector by Display Features Analysis

Directory of Open Access Journals (Sweden)

ChinLun Lai

2016-07-01

Full Text Available In this paper, a smart face liveness detector is proposed to prevent the biometric system from being “deceived” by the video or picture of a valid user that the counterfeiter took with a high definition handheld device (e.g., iPad with retina display. By analyzing the characteristics of the display platform and using an expert decision-making core, we can effectively detect whether a spoofing action comes from a fake face displayed in the high definition display by verifying the chromaticity regions in the captured face. That is, a live or spoof face can be distinguished precisely by the designed optical image sensor. To sum up, by the proposed method/system, a normal optical image sensor can be upgraded to a powerful version to detect the spoofing actions. The experimental results prove that the proposed detection system can achieve very high detection rate compared to the existing methods and thus be practical to implement directly in the authentication systems.

A Smart Spoofing Face Detector by Display Features Analysis.

Science.gov (United States)

Lai, ChinLun; Tai, ChiuYuan

2016-07-21

In this paper, a smart face liveness detector is proposed to prevent the biometric system from being "deceived" by the video or picture of a valid user that the counterfeiter took with a high definition handheld device (e.g., iPad with retina display). By analyzing the characteristics of the display platform and using an expert decision-making core, we can effectively detect whether a spoofing action comes from a fake face displayed in the high definition display by verifying the chromaticity regions in the captured face. That is, a live or spoof face can be distinguished precisely by the designed optical image sensor. To sum up, by the proposed method/system, a normal optical image sensor can be upgraded to a powerful version to detect the spoofing actions. The experimental results prove that the proposed detection system can achieve very high detection rate compared to the existing methods and thus be practical to implement directly in the authentication systems.

On-chip electrochromic micro display for a disposable bio-sensor chip

Science.gov (United States)

Zhu, Yanjun; Tsukamoto, Takashiro; Tanaka, Shuji

2017-12-01

This paper reports an on-chip electrochromic micro display made of polyaniline (PANi) which can be easily made on a CMOS chip. Micro-patterned PANi thin films were selectively deposited on pre-patterned microelectrodes by using electrodeposition. The optimum conditions for deposition and electrochromism were investigated. An 8-pixel on-chip micro display was made on a Si chip. The color of each PANi film could be independently but simultaneously controlled, which means any 1-byte digital data could be displayed on the display. The PANi display had a response time as fast as about 100 ms, which means the transfer data rate was as fast as 80 bits per second.

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.

Fringe effect of electrical capacitance and resistance tomography sensors

International Nuclear Information System (INIS)

Sun, Jiangtao; Yang, Wuqiang

2013-01-01

Because of the ‘soft-field’ nature, all electrical tomography sensors suffer from electric field distortion, i.e. the fringe effect. In electrical resistance tomography (ERT) sensors, small pin electrodes are commonly used. It is well known that the pin electrodes result in severe electric field distortion or the fringe effect, and the sensing region of such an ERT sensor spreads out of the pin electrode plane to a large volume. This is also true for electrical capacitance tomography (ECT) sensors, even though it is less severe because of larger electrodes and grounded end guards used. However, when the length of electrodes in an ECT sensor without guards is reduced to almost the same dimension as those in an ERT sensor, the fringe effect is equally obvious. To investigate the fringe effect of ERT and ECT sensors with and without guards, simulations were carried out with different length of electrodes and the results are compared with the corresponding 2D simulation. It is concluded that ECT and ERT sensors with longer electrodes have less fringe effect. Because grounded end guards are effective in reducing the fringe effect of ECT sensors, we propose to apply grounded guards in ERT sensors and integrate ECT and ERT sensors together. Simulation results reveal that ERT sensors with grounded guards have less fringe effect. While commonly current excitation is used with ERT sensors, we propose voltage excitation instead to apply the grounded guards. The feasibility of this approach has been verified by experiment. Finally, a common structure for reducing the fringe effect is proposed for ECT and ERT sensors for the first time to simplify the sensor structure and reduce the mutual interference in ECT/ERT dual-modality measurements. (paper)

Geospace Science from Ground-based Magnetometer Arrays: Advances in Sensors, Data Collection, and Data Integration

Science.gov (United States)

Mann, Ian; Chi, Peter

2016-07-01

Networks of ground-based magnetometers now provide the basis for the diagnosis of magnetic disturbances associated with solar wind-magnetosphere-ionosphere coupling on a truly global scale. Advances in sensor and digitisation technologies offer increases in sensitivity in fluxgate, induction coil, and new micro-sensor technologies - including the promise of hybrid sensors. Similarly, advances in remote connectivity provide the capacity for truly real-time monitoring of global dynamics at cadences sufficient for monitoring and in many cases resolving system level spatio-temporal ambiguities especially in combination with conjugate satellite measurements. A wide variety of the plasmaphysical processes active in driving geospace dynamics can be monitored based on the response of the electrical current system, including those associated with changes in global convection, magnetospheric substorms and nightside tail flows, as well as due to solar wind changes in both dynamic pressure and in response to rotations of the direction of the IMF. Significantly, any changes to the dynamical system must be communicated by the propagation of long-period Alfven and/or compressional waves. These wave populations hence provide diagnostics for not only the energy transport by the wave fields themselves, but also provide a mechanism for diagnosing the structure of the background plasma medium through which the waves propagate. Ultra-low frequency (ULF) waves are especially significant in offering a monitor for mass density profiles, often invisible to particle detectors because of their very low energy, through the application of a variety of magneto-seismology and cross-phase techniques. Renewed scientific interest in the plasma waves associated with near-Earth substorm dynamics, including magnetosphere-ionosphere coupling at substorm onset and their relation to magnetotail flows, as well the importance of global scale ultra-low frequency waves for the energisation, transport

Porous Silicon Sensors- Elusive and Erudite

OpenAIRE

H. Saha, Prof.

2017-01-01

Porous Silicon Sensors have been fabricated and tested successfully over the last few years as humidity sensors, vapour sensors, gas sensors, piezoresistive pressure sensors and bio- sensors. In each case it has displayed remarkably sensitivity, relatively low temperature operation and ease of fabrication. Brief description of fabrication and properties of all these types of different sensors is reported in this paper. The barriers of porous silicon like contact, non- uniformity, instability ...

OLED Display For Real Time Vision System

Directory of Open Access Journals (Sweden)

Sandhyalakshmi Narayanan

2015-08-01

Full Text Available This innovative glass design will carry an OLED based display controlled via nano Ardiuno board having Bluetooth connectivity with a Smartphone to exchange information along with onboard accelerometer. We are using a tilt angle sensor for detecting if the driver is feeling drowsy. An alcohol sensor has been used to promote the safe driving habit. The glasses will be getting latest updates about the current speed of the vehicle navigation directions nearby or approaching sign broads or services like petrol pumps. Itll also display information like incoming calls or received messages. All this information will be obtained through a Smartphone connected via Bluetooth. Also the car mileage can be monitored with help of fuel sensor as the consumption of fuel is directly related to it. Abnormalities if detected will be immediately notified in the glasses. Also the angle of the tilt angle sensor can be defined and set by the user according to his needs. Also the main idea of using OLED glasses is that it is organic thereby helps in reducing the carbon footprint and is quite slim. Therefore it can be easily mounted on the specs without making it heavy. Also they higher level of flexibility and have low power drain and energy consumption

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

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.

Electric field sensor studies

International Nuclear Information System (INIS)

Griffith, R.D.; Parks, S.

1977-01-01

Above-ground intrusion sensors are reviewed briefly. Buried wire sensors are next considered; feasibility studies were conducted. A triangular system of an overhead transmitter wire exciting two buried sensor wires was developed and tested. It failed sometimes to detect a man making a broad jump. A differential receiver was developed to solve this problem

OLED Display For Real Time Vision System

OpenAIRE

Sandhyalakshmi Narayanan; Sanjana Sridhar; Neha Deshpande; Ashwini Gaikwad

2015-01-01

This innovative glass design will carry an OLED based display controlled via nano Ardiuno board having Bluetooth connectivity with a Smartphone to exchange information along with onboard accelerometer. We are using a tilt angle sensor for detecting if the driver is feeling drowsy. An alcohol sensor has been used to promote the safe driving habit. The glasses will be getting latest updates about the current speed of the vehicle navigation directions nearby or approaching sign broads or service...

Demonstration of MPV Sensor at Yuma Proving Ground, AZ

Science.gov (United States)

2011-06-01

test plot in Ashland, OR, where magnetic soils have shown to have a significant effect on EMI sensors ( Pasion et al., 2008). The recorded signal...sensors was also investigated during that survey as part of SERDP MM-1573 (PI: Len Pasion , Sky Research). The MPV offers possibilities to defeat...of magnetic soils (Lhomme et al., 2008; Pasion et al., 2008). The MPV response due to sensor motion and topography over magnetic soil is predicable

A Tilt, Soil Moisture, and Pore Water Pressure Sensor System for Slope Monitoring Applications

Directory of Open Access Journals (Sweden)

Rosanno de Dios

2009-06-01

Full Text Available This paper describes the design, implementation and characterization of a sensor network intended for monitoring of slope deformation and potential failures. The sensor network system consists of a tilt and moisture sensor column, a pore water pressure sensor column and a personal computer for data storage and processing. The tilt sensor column consists of several pipe segments containing tri-axial accelerometers and signal processing electronics. Each segment is joined together by flexible joints to allow for the column to deform and subsequently track underground movement. Capacitive-type sensors for soil moisture measurement are also included in the sensor column, which are used to measure the soil moisture at different depths. The measurements at each segment are transferred via a Controller Area Network (CAN bus, where the CAN master node is located at the top of the column above ground. The CAN master node transmits the collected data from the slave nodes via a wireless connection to a personal computer that performs data storage, processing and display via a Python-based graphical user interface (GUI. The entire system was deployed and characterized on a small-scale slope model. Slope failure was induced via water seepage and the system was demonstrated to ably measure the inclination and soil moisture content throughout the landslide event.

Water-Cut Sensor System

KAUST Repository

Karimi, Muhammad Akram; Shamim, Atif; Arsalan, Muhammad

2018-01-01

Provided in some embodiments is a method of manufacturing a pipe conformable water-cut sensors system. Provided in some embodiments is method for manufacturing a water-cut sensor system that includes providing a helical T-resonator, a helical ground

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.

Networked sensors for the combat forces

Science.gov (United States)

Klager, Gene

2004-11-01

Real-time and detailed information is critical to the success of ground combat forces. Current manned reconnaissance, surveillance, and target acquisition (RSTA) capabilities are not sufficient to cover battlefield intelligence gaps, provide Beyond-Line-of-Sight (BLOS) targeting, and the ambush avoidance information necessary for combat forces operating in hostile situations, complex terrain, and conducting military operations in urban terrain. This paper describes a current US Army program developing advanced networked unmanned/unattended sensor systems to survey these gaps and provide the Commander with real-time, pertinent information. Networked Sensors for the Combat Forces plans to develop and demonstrate a new generation of low cost distributed unmanned sensor systems organic to the RSTA Element. Networked unmanned sensors will provide remote monitoring of gaps, will increase a unit"s area of coverage, and will provide the commander organic assets to complete his Battlefield Situational Awareness (BSA) picture for direct and indirect fire weapons, early warning, and threat avoidance. Current efforts include developing sensor packages for unmanned ground vehicles, small unmanned aerial vehicles, and unattended ground sensors using advanced sensor technologies. These sensors will be integrated with robust networked communications and Battle Command tools for mission planning, intelligence "reachback", and sensor data management. The network architecture design is based on a model that identifies a three-part modular design: 1) standardized sensor message protocols, 2) Sensor Data Management, and 3) Service Oriented Architecture. This simple model provides maximum flexibility for data exchange, information management and distribution. Products include: Sensor suites optimized for unmanned platforms, stationary and mobile versions of the Sensor Data Management Center, Battle Command planning tools, networked communications, and sensor management software. Details

Two and three dimensional core power distribution monitor and display

International Nuclear Information System (INIS)

Impink, A.J. Jr.; Grobmyer, L.R.

1988-01-01

This patent describes a sensor monitoring system for displaying a profile of fractional deviations in relative coolant enthalpy rise over a defined area comprising at least a part of a core of a nuclear reactor, which system comprises: core exit coolant temperature sensors positioned to monitor at least a portion of the defined area; an inlet temperature sensor outside the core which monitors the temperature of core coolant at an inlet to the reactor means, responsive to the outputs from both the core exit temperature sensors and the inlet temperature sensor, for generating corresponding representative values of actual coolant enthalpy rise and corresponding values of relative enthalpy rise at each location in the defined area at which a core exit coolant temperature sensor is available; means, responsive to the generated values of relative enthalpy rise and to reference values of relative enthalpy rise at corresponding locations in the defined area, for generating values of the fractional deviation of the measured values of relative enthalpy rise from the corresponding values; means for interpolating the generated values of fractional deviation in relative enthalpy rise to provide interpolated values of fractional deviation in relative enthalpy rise at locations in the defined area of the core other than those at which core exit coolant temperature sensors are available; and means for multidimensionally displaying the generated and interpolated values

Process Simulation and Characterization of Substrate Engineered Silicon Thin Film Transistor for Display Sensors and Large Area Electronics

International Nuclear Information System (INIS)

Hashmi, S M; Ahmed, S

2013-01-01

Design, simulation, fabrication and post-process qualification of substrate-engineered Thin Film Transistors (TFTs) are carried out to suggest an alternate manufacturing process step focused on display sensors and large area electronics applications. Damage created by ion implantation of Helium and Silicon ions into single-crystalline n-type silicon substrate provides an alternate route to create an amorphized region responsible for the fabrication of TFT structures with controllable and application-specific output parameters. The post-process qualification of starting material and full-cycle devices using Rutherford Backscattering Spectrometry (RBS) and Proton or Particle induced X-ray Emission (PIXE) techniques also provide an insight to optimize the process protocols as well as their applicability in the manufacturing cycle

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

Airfield Ground Safety

National Research Council Canada - National Science Library

Petrescu, Jon

2000-01-01

.... The system developed under AGS, called the Ground Safety Tracking and Reporting System, uses multisensor data fusion from in-pavement inductive loop sensors to address a critical problem affecting out nation's airports: runway incursions...

Intelligent sensor networks the integration of sensor networks, signal processing and machine learning

CERN Document Server

Hu, Fei

2012-01-01

Although governments worldwide have invested significantly in intelligent sensor network research and applications, few books cover intelligent sensor networks from a machine learning and signal processing perspective. Filling this void, Intelligent Sensor Networks: The Integration of Sensor Networks, Signal Processing and Machine Learning focuses on the close integration of sensing, networking, and smart signal processing via machine learning. Based on the world-class research of award-winning authors, the book provides a firm grounding in the fundamentals of intelligent sensor networks, incl

Innovative characterization techniques and decision support systems for ground water contamination projects

International Nuclear Information System (INIS)

Hoffman, F.

1992-07-01

Ground water contamination projects throughout the world must be approached as individual and unique problems. Many traditional investigation techniques require modification to meet the needs of site-specific situations. Because the age of the science of contaminant hydrogeology can be measured only in a few decades, the field is ripe for innovation. This paper describes the following new technologies: At Lawrence Livermore National Laboratory (LLNL), we have developed a new drilling and sampling method, which allows the evaluation of the vertical extent of contamination in a single borehole. We are also using new fiber-optic-based chemical analytical sensors that promise to greatly increase the case of obtaining chemical analyses in the subsurface while greatly reducing costs. Because ground water investigations are data intensive, we need the best decision support system information tools to proceed with investigation and cleanup. These tools have three components: a relational database, data analysis tools, and tools for data display

Biomimetic virus-based colourimetric sensors

Science.gov (United States)

Oh, Jin-Woo; Chung, Woo-Jae; Heo, Kwang; Jin, Hyo-Eon; Lee, Byung Yang; Wang, Eddie; Zueger, Chris; Wong, Winnie; Meyer, Joel; Kim, Chuntae; Lee, So-Young; Kim, Won-Geun; Zemla, Marcin; Auer, Manfred; Hexemer, Alexander; Lee, Seung-Wuk

2014-01-01

Many materials in nature change colours in response to stimuli, making them attractive for use as sensor platform. However, both natural materials and their synthetic analogues lack selectivity towards specific chemicals, and introducing such selectivity remains a challenge. Here we report the self-assembly of genetically engineered viruses (M13 phage) into target-specific, colourimetric biosensors. The sensors are composed of phage-bundle nanostructures and exhibit viewing-angle independent colour, similar to collagen structures in turkey skin. On exposure to various volatile organic chemicals, the structures rapidly swell and undergo distinct colour changes. Furthermore, sensors composed of phage displaying trinitrotoluene (TNT)-binding peptide motifs identified from a phage display selectively distinguish TNT down to 300 p.p.b. over similarly structured chemicals. Our tunable, colourimetric sensors can be useful for the detection of a variety of harmful toxicants and pathogens to protect human health and national security.

Flight Test Result for the Ground-Based Radio Navigation System Sensor with an Unmanned Air Vehicle.

Science.gov (United States)

Jang, Jaegyu; Ahn, Woo-Guen; Seo, Seungwoo; Lee, Jang Yong; Park, Jun-Pyo

2015-11-11

The Ground-based Radio Navigation System (GRNS) is an alternative/backup navigation system based on time synchronized pseudolites. It has been studied for some years due to the potential vulnerability issue of satellite navigation systems (e.g., GPS or Galileo). In the framework of our study, a periodic pulsed sequence was used instead of the randomized pulse sequence recommended as the RTCM (radio technical commission for maritime services) SC (special committee)-104 pseudolite signal, as a randomized pulse sequence with a long dwell time is not suitable for applications requiring high dynamics. This paper introduces a mathematical model of the post-correlation output in a navigation sensor, showing that the aliasing caused by the additional frequency term of a periodic pulsed signal leads to a false lock (i.e., Doppler frequency bias) during the signal acquisition process or in the carrier tracking loop of the navigation sensor. We suggest algorithms to resolve the frequency false lock issue in this paper, relying on the use of a multi-correlator. A flight test with an unmanned helicopter was conducted to verify the implemented navigation sensor. The results of this analysis show that there were no false locks during the flight test and that outliers stem from bad dilution of precision (DOP) or fluctuations in the received signal quality.

Ground Monitoring Neotropical Dry Forests: A Sensor Network for Forest and Microclimate Dynamics in Semi-Arid Environments (Enviro-Net°)

Science.gov (United States)

Rankine, C. J.; Sánchez-Azofeifa, G.

2011-12-01

In the face of unprecedented global change driven by anthropogenic pressure on natural systems it has become imperative to monitor and better understand potential shifts in ecosystem functioning and services from local to global scales. The utilization of automated sensors technologies offers numerous advantages over traditional on-site ecosystem surveying techniques and, as a result, sensor networks are becoming a powerful tool in environmental monitoring programs. Tropical forests, renowned for their biodiversity, are important regulators of land-atmosphere fluxes yet the seasonally dry tropical forests, which account for 40% of forested ecosystems in the American tropics, have been severely degraded over the past several decades and not much is known of their capacity to recover. With less than 1% of these forests protected, our ability to monitor the dynamics and quantify changes in the remaining primary and recovering secondary tropical dry forests is vital to understanding mechanisms of ecosystem stress responses and climate feedback with respect to annual productivity and desertification processes in the tropics. The remote sensing component of the Tropi-Dry: Human and Biophysical Dimensions of Tropical Dry Forests in the Americas research network supports a network of long-term tropical ecosystem monitoring platforms which focus on the dynamics of seasonally dry tropical forests in the Americas. With over 25 sensor station deployments operating across a latitudinal gradient in Mexico, Costa Rica, Brazil, and Argentina continuously collecting hyper-temporal sensory input based on standardized deployment parameters, this monitoring system is unique among tropical environments. Technologies used in the network include optical canopy phenology towers, understory wireless sensing networks, above and below ground microclimate stations, and digital cameras. Sensory data streams are uploaded to a cyber-infrastructure initiative, denominated Enviro-Net°, for data

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.

Feasibility Study of Haptic Display for Rotation Tasks of Wrist Work

OpenAIRE

曽根, 順治; 岩井, 秀樹; 山田, 勝実; 陳, 軍; 徳山, 喜政; 今野, 晃市; Sone, Junji; Iwai, Hideki; Yamada, Katsumi; Chen, Jun; Tokuyama, Yoshimasa; Konno, Kouichi

2011-01-01

We have developed a haptic display for rotational tasks that involve functions of the human wrist. We represent the torque using a motor and a brake. Reference torque curves are obtained by the measuring torque required for each actual task using a torque sensor. The brake represents the stop condition. We have confirmed the effectiveness of the display by comparing the actual tasks with the haptic display experiment.

Autonomous Aerial Refueling Ground Test Demonstration—A Sensor-in-the-Loop, Non-Tracking Method

Directory of Open Access Journals (Sweden)

Chao-I Chen

2015-05-01

Full Text Available An essential capability for an unmanned aerial vehicle (UAV to extend its airborne duration without increasing the size of the aircraft is called the autonomous aerial refueling (AAR. This paper proposes a sensor-in-the-loop, non-tracking method for probe-and-drogue style autonomous aerial refueling tasks by combining sensitivity adjustments of a 3D Flash LIDAR camera with computer vision based image-processing techniques. The method overcomes the inherit ambiguity issues when reconstructing 3D information from traditional 2D images by taking advantage of ready to use 3D point cloud data from the camera, followed by well-established computer vision techniques. These techniques include curve fitting algorithms and outlier removal with the random sample consensus (RANSAC algorithm to reliably estimate the drogue center in 3D space, as well as to establish the relative position between the probe and the drogue. To demonstrate the feasibility of the proposed method on a real system, a ground navigation robot was designed and fabricated. Results presented in the paper show that using images acquired from a 3D Flash LIDAR camera as real time visual feedback, the ground robot is able to track a moving simulated drogue and continuously narrow the gap between the robot and the target autonomously.

Implications of sensor design for coral reef detection: Upscaling ground hyperspectral imagery in spatial and spectral scales

Science.gov (United States)

Caras, Tamir; Hedley, John; Karnieli, Arnon

2017-12-01

Remote sensing offers a potential tool for large scale environmental surveying and monitoring. However, remote observations of coral reefs are difficult especially due to the spatial and spectral complexity of the target compared to sensor specifications as well as the environmental implications of the water medium above. The development of sensors is driven by technological advances and the desired products. Currently, spaceborne systems are technologically limited to a choice between high spectral resolution and high spatial resolution, but not both. The current study explores the dilemma of whether future sensor design for marine monitoring should prioritise on improving their spatial or spectral resolution. To address this question, a spatially and spectrally resampled ground-level hyperspectral image was used to test two classification elements: (1) how the tradeoff between spatial and spectral resolutions affects classification; and (2) how a noise reduction by majority filter might improve classification accuracy. The studied reef, in the Gulf of Aqaba (Eilat), Israel, is heterogeneous and complex so the local substrate patches are generally finer than currently available imagery. Therefore, the tested spatial resolution was broadly divided into four scale categories from five millimeters to one meter. Spectral resolution resampling aimed to mimic currently available and forthcoming spaceborne sensors such as (1) Environmental Mapping and Analysis Program (EnMAP) that is characterized by 25 bands of 6.5 nm width; (2) VENμS with 12 narrow bands; and (3) the WorldView series with broadband multispectral resolution. Results suggest that spatial resolution should generally be prioritized for coral reef classification because the finer spatial scale tested (pixel size mind, while the focus in this study was on the technologically limited spaceborne design, aerial sensors may presently provide an opportunity to implement the suggested setup.

Coincident Observation of Lightning using Spaceborne Spectrophotometer and Ground-Level Electromagnetic Sensors

Science.gov (United States)

Adachi, Toru; Cohen, Morris; Li, Jingbo; Cummer, Steve; Blakeslee, Richard; Marshall, THomas; Stolzenberg, Maribeth; Karunarathne, Sumedhe; Hsu, Rue-Ron; Su, Han-Tzong;

Wireless Sensor Node for Autonomous Monitoring and Alerts in Remote Environments

Science.gov (United States)

Monacos, Steve P. (Inventor); Panangadan, Anand V. (Inventor)

2015-01-01

A method, apparatus, system, and computer program products provides personal alert and tracking capabilities using one or more nodes. Each node includes radio transceiver chips operating at different frequency ranges, a power amplifier, sensors, a display, and embedded software. The chips enable the node to operate as either a mobile sensor node or a relay base station node while providing a long distance relay link between nodes. The power amplifier enables a line-of-sight communication between the one or more nodes. The sensors provide a GPS signal, temperature, and accelerometer information (used to trigger an alert condition). The embedded software captures and processes the sensor information, provides a multi-hop packet routing protocol to relay the sensor information to and receive alert information from a command center, and to display the alert information on the display.

Ambulatory Measurement of Ground Reaction Forces

NARCIS (Netherlands)

Veltink, Peter H.; Liedtke, Christian; Droog, Ed

2004-01-01

The measurement of ground reaction forces is important in the biomechanical analysis of gait and other motor activities. It is the purpose of this study to show the feasibility of ambulatory measurement of ground reaction forces using two six degrees of freedom sensors mounted under the shoe. One

A New Proxy Measurement Algorithm with Application to the Estimation of Vertical Ground Reaction Forces Using Wearable Sensors.

Science.gov (United States)

Guo, Yuzhu; Storm, Fabio; Zhao, Yifan; Billings, Stephen A; Pavic, Aleksandar; Mazzà, Claudia; Guo, Ling-Zhong

2017-09-22

Measurement of the ground reaction forces (GRF) during walking is typically limited to laboratory settings, and only short observations using wearable pressure insoles have been reported so far. In this study, a new proxy measurement method is proposed to estimate the vertical component of the GRF (vGRF) from wearable accelerometer signals. The accelerations are used as the proxy variable. An orthogonal forward regression algorithm (OFR) is employed to identify the dynamic relationships between the proxy variables and the measured vGRF using pressure-sensing insoles. The obtained model, which represents the connection between the proxy variable and the vGRF, is then used to predict the latter. The results have been validated using pressure insoles data collected from nine healthy individuals under two outdoor walking tasks in non-laboratory settings. The results show that the vGRFs can be reconstructed with high accuracy (with an average prediction error of less than 5.0%) using only one wearable sensor mounted at the waist (L5, fifth lumbar vertebra). Proxy measures with different sensor positions are also discussed. Results show that the waist acceleration-based proxy measurement is more stable with less inter-task and inter-subject variability than the proxy measures based on forehead level accelerations. The proposed proxy measure provides a promising low-cost method for monitoring ground reaction forces in real-life settings and introduces a novel generic approach for replacing the direct determination of difficult to measure variables in many applications.

A New Proxy Measurement Algorithm with Application to the Estimation of Vertical Ground Reaction Forces Using Wearable Sensors

Directory of Open Access Journals (Sweden)

Yuzhu Guo

2017-09-01

Full Text Available Measurement of the ground reaction forces (GRF during walking is typically limited to laboratory settings, and only short observations using wearable pressure insoles have been reported so far. In this study, a new proxy measurement method is proposed to estimate the vertical component of the GRF (vGRF from wearable accelerometer signals. The accelerations are used as the proxy variable. An orthogonal forward regression algorithm (OFR is employed to identify the dynamic relationships between the proxy variables and the measured vGRF using pressure-sensing insoles. The obtained model, which represents the connection between the proxy variable and the vGRF, is then used to predict the latter. The results have been validated using pressure insoles data collected from nine healthy individuals under two outdoor walking tasks in non-laboratory settings. The results show that the vGRFs can be reconstructed with high accuracy (with an average prediction error of less than 5.0% using only one wearable sensor mounted at the waist (L5, fifth lumbar vertebra. Proxy measures with different sensor positions are also discussed. Results show that the waist acceleration-based proxy measurement is more stable with less inter-task and inter-subject variability than the proxy measures based on forehead level accelerations. The proposed proxy measure provides a promising low-cost method for monitoring ground reaction forces in real-life settings and introduces a novel generic approach for replacing the direct determination of difficult to measure variables in many applications.

Humpback whale song and foraging behavior on an antarctic feeding ground.

Directory of Open Access Journals (Sweden)

Alison K Stimpert

Full Text Available Reports of humpback whale (Megaptera novaeangliae song chorusing occurring outside the breeding grounds are becoming more common, but song structure and underwater behavior of individual singers on feeding grounds and migration routes remain unknown. Here, ten humpback whales in the Western Antarctic Peninsula were tagged in May 2010 with non-invasive, suction-cup attached tags to study foraging ecology and acoustic behavior. Background song was identified on all ten records, but additionally, acoustic records of two whales showed intense and continuous singing, with a level of organization and structure approaching that of typical breeding ground song. The songs, produced either by the tagged animals or close associates, shared phrase types and theme structure with one another, and some song bouts lasted close to an hour. Dive behavior of tagged animals during the time of sound production showed song occurring during periods of active diving, sometimes to depths greater than 100 m. One tag record also contained song in the presence of feeding lunges identified from the behavioral sensors, indicating that mating displays occur in areas worthy of foraging. These data show behavioral flexibility as the humpbacks manage competing needs to continue to feed and to prepare for the breeding season during late fall. This may also signify an ability to engage in breeding activities outside of the traditional, warm water breeding ground locations.

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.

Augmenting digital displays with computation

Science.gov (United States)

Liu, Jing

rate for traditional displays is not enough for some computational displays that show complex image patterns. The study focuses on displays with hidden channels, and their application to 3D+2D TV. By taking advantage of the fast growing power of computation and sensors, these four novel display setups - in combination with display algorithms - advance the frontier of computational display research.

Multi-Sensor Mud Detection

Science.gov (United States)

Rankin, Arturo L.; Matthies, Larry H.

2010-01-01

Robust mud detection is a critical perception requirement for Unmanned Ground Vehicle (UGV) autonomous offroad navigation. A military UGV stuck in a mud body during a mission may have to be sacrificed or rescued, both of which are unattractive options. There are several characteristics of mud that may be detectable with appropriate UGV-mounted sensors. For example, mud only occurs on the ground surface, is cooler than surrounding dry soil during the daytime under nominal weather conditions, is generally darker than surrounding dry soil in visible imagery, and is highly polarized. However, none of these cues are definitive on their own. Dry soil also occurs on the ground surface, shadows, snow, ice, and water can also be cooler than surrounding dry soil, shadows are also darker than surrounding dry soil in visible imagery, and cars, water, and some vegetation are also highly polarized. Shadows, snow, ice, water, cars, and vegetation can all be disambiguated from mud by using a suite of sensors that span multiple bands in the electromagnetic spectrum. Because there are military operations when it is imperative for UGV's to operate without emitting strong, detectable electromagnetic signals, passive sensors are desirable. JPL has developed a daytime mud detection capability using multiple passive imaging sensors. Cues for mud from multiple passive imaging sensors are fused into a single mud detection image using a rule base, and the resultant mud detection is localized in a terrain map using range data generated from a stereo pair of color cameras.

AGSM Intelligent Devices/Smart Sensors Project

Science.gov (United States)

Harp, Janicce Leshay

2014-01-01

This project provides development and qualification of Smart Sensors capable of self-diagnosis and assessment of their capability/readiness to support operations. These sensors will provide pressure and temperature measurements to use in ground systems.

Optimized autonomous space in-situ sensor web for volcano monitoring

Science.gov (United States)

Song, W.-Z.; Shirazi, B.; Huang, R.; Xu, M.; Peterson, N.; LaHusen, R.; Pallister, J.; Dzurisin, D.; Moran, S.; Lisowski, M.; Kedar, S.; Chien, S.; Webb, F.; Kiely, A.; Doubleday, J.; Davies, A.; Pieri, D.

2010-01-01

In response to NASA's announced requirement for Earth hazard monitoring sensor-web technology, a multidisciplinary team involving sensor-network experts (Washington State University), space scientists (JPL), and Earth scientists (USGS Cascade Volcano Observatory (CVO)), have developed a prototype of dynamic and scalable hazard monitoring sensor-web and applied it to volcano monitoring. The combined Optimized Autonomous Space In-situ Sensor-web (OASIS) has two-way communication capability between ground and space assets, uses both space and ground data for optimal allocation of limited bandwidth resources on the ground, and uses smart management of competing demands for limited space assets. It also enables scalability and seamless infusion of future space and in-situ assets into the sensor-web. The space and in-situ control components of the system are integrated such that each element is capable of autonomously tasking the other. The ground in-situ was deployed into the craters and around the flanks of Mount St. Helens in July 2009, and linked to the command and control of the Earth Observing One (EO-1) satellite. ?? 2010 IEEE.

Urodynamic pressure sensor

Science.gov (United States)

Moore, Thomas

1991-01-01

A transducer system was developed for measuring the closing pressure profile along the female urethra, which provides up to five sensors within the functional length of the urethra. This new development is an improvement over an earlier measurement method that has a smaller sensor area and was unable to respond to transient events. Three sensors were constructed; one of them was subjected to approximately eight hours of use in a clinical setting during which 576 data points were obtained. The complete instrument system, including the signal conditioning electronics, data acquisition unit, and the computer with its display and printer is described and illustrated.

A New User Interface for On-Demand Customizable Data Products for Sensors in a SensorWeb

Science.gov (United States)

Mandl, Daniel; Cappelaere, Pat; Frye, Stuart; Sohlberg, Rob; Ly, Vuong; Chien, Steve; Sullivan, Don

2011-01-01

A SensorWeb is a set of sensors, which can consist of ground, airborne and space-based sensors interoperating in an automated or autonomous collaborative manner. The NASA SensorWeb toolbox, developed at NASA/GSFC in collaboration with NASA/JPL, NASA/Ames and other partners, is a set of software and standards that (1) enables users to create virtual private networks of sensors over open networks; (2) provides the capability to orchestrate their actions; (3) provides the capability to customize the output data products and (4) enables automated delivery of the data products to the users desktop. A recent addition to the SensorWeb Toolbox is a new user interface, together with web services co-resident with the sensors, to enable rapid creation, loading and execution of new algorithms for processing sensor data. The web service along with the user interface follows the Open Geospatial Consortium (OGC) standard called Web Coverage Processing Service (WCPS). This presentation will detail the prototype that was built and how the WCPS was tested against a HyspIRI flight testbed and an elastic computation cloud on the ground with EO-1 data. HyspIRI is a future NASA decadal mission. The elastic computation cloud stores EO-1 data and runs software similar to Amazon online shopping.

Unattended Ground Sensors for Expeditionary Force 21 Intelligence Collections

Science.gov (United States)

2015-06-01

little impact on modern intelligence collections. This thesis analyzes and compares the units and individual Marine skillsets that employ UGS, and the...the sensor employment planning cycle, and the socialization of this plan through the proper chain-of-command [4]. Figure 8 depicts the Sensor...the use of newly developed cellphone based technologies and emerging UGS capabilities to assist in Listening Post/ Observation Post (LP/OP

Autonomous Mission Operations for Sensor Webs

Science.gov (United States)

Underbrink, A.; Witt, K.; Stanley, J.; Mandl, D.

2008-12-01

We present interim results of a 2005 ROSES AIST project entitled, "Using Intelligent Agents to Form a Sensor Web for Autonomous Mission Operations", or SWAMO. The goal of the SWAMO project is to shift the control of spacecraft missions from a ground-based, centrally controlled architecture to a collaborative, distributed set of intelligent agents. The network of intelligent agents intends to reduce management requirements by utilizing model-based system prediction and autonomic model/agent collaboration. SWAMO agents are distributed throughout the Sensor Web environment, which may include multiple spacecraft, aircraft, ground systems, and ocean systems, as well as manned operations centers. The agents monitor and manage sensor platforms, Earth sensing systems, and Earth sensing models and processes. The SWAMO agents form a Sensor Web of agents via peer-to-peer coordination. Some of the intelligent agents are mobile and able to traverse between on-orbit and ground-based systems. Other agents in the network are responsible for encapsulating system models to perform prediction of future behavior of the modeled subsystems and components to which they are assigned. The software agents use semantic web technologies to enable improved information sharing among the operational entities of the Sensor Web. The semantics include ontological conceptualizations of the Sensor Web environment, plus conceptualizations of the SWAMO agents themselves. By conceptualizations of the agents, we mean knowledge of their state, operational capabilities, current operational capacities, Web Service search and discovery results, agent collaboration rules, etc. The need for ontological conceptualizations over the agents is to enable autonomous and autonomic operations of the Sensor Web. The SWAMO ontology enables automated decision making and responses to the dynamic Sensor Web environment and to end user science requests. The current ontology is compatible with Open Geospatial Consortium (OGC

Bio-inspired approach for intelligent unattended ground sensors

Science.gov (United States)

Hueber, Nicolas; Raymond, Pierre; Hennequin, Christophe; Pichler, Alexander; Perrot, Maxime; Voisin, Philippe; Moeglin, Jean-Pierre

2015-05-01

Improving the surveillance capacity over wide zones requires a set of smart battery-powered Unattended Ground Sensors capable of issuing an alarm to a decision-making center. Only high-level information has to be sent when a relevant suspicious situation occurs. In this paper we propose an innovative bio-inspired approach that mimics the human bi-modal vision mechanism and the parallel processing ability of the human brain. The designed prototype exploits two levels of analysis: a low-level panoramic motion analysis, the peripheral vision, and a high-level event-focused analysis, the foveal vision. By tracking moving objects and fusing multiple criteria (size, speed, trajectory, etc.), the peripheral vision module acts as a fast relevant event detector. The foveal vision module focuses on the detected events to extract more detailed features (texture, color, shape, etc.) in order to improve the recognition efficiency. The implemented recognition core is able to acquire human knowledge and to classify in real-time a huge amount of heterogeneous data thanks to its natively parallel hardware structure. This UGS prototype validates our system approach under laboratory tests. The peripheral analysis module demonstrates a low false alarm rate whereas the foveal vision correctly focuses on the detected events. A parallel FPGA implementation of the recognition core succeeds in fulfilling the embedded application requirements. These results are paving the way of future reconfigurable virtual field agents. By locally processing the data and sending only high-level information, their energy requirements and electromagnetic signature are optimized. Moreover, the embedded Artificial Intelligence core enables these bio-inspired systems to recognize and learn new significant events. By duplicating human expertise in potentially hazardous places, our miniature visual event detector will allow early warning and contribute to better human decision making.

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.

Ground Motion Analysis of Co-Located DAS and Seismometer Sensors

Science.gov (United States)

Wang, H. F.; Fratta, D.; Lord, N. E.; Lancelle, C.; Thurber, C. H.; Zeng, X.; Parker, L.; Chalari, A.; Miller, D.; Feigl, K. L.; Team, P.

2016-12-01

The PoroTomo research team deployed 8700-meters of Distributed Acoustic Sensing (DAS) cable in a shallow trench and 400-meters in a borehole at Brady Hot Springs, Nevada in March 2016 together with an array of 246, three-component geophones. The seismic sensors occupied a natural laboratory 1500 x 500 x 400 meters overlying the Brady geothermal field. The DAS cable was laid out in three parallel zig-zag lines with line segments approximately 100-meters in length and geophones were spaced at approximately 50-m intervals. In several line segments, geophones were co-located within one meter of the DAS cable. Both DAS and the conventional geophones recorded continuously over 15 days. A large Vibroseis truck (T-Rex) provided the seismic source at approximately 250 locations outside and within the array. The Vibroseis protocol called for excitation in one vertical and two orthogonal horizontal directions at each location. For each mode, three, 5-to-80-Hz upsweeps were made over 20 seconds. In addition, a moderate-sized earthquake with a local magnitude of 4.3 was recorded on March 21, 2016. Its epicenter was approximately 150-km away. Several DAS line segments with co-located geophone stations were used to test relationships between the strain rate recorded by DAS and ground velocity recorded by the geophones.

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.

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.

Response of a Zn2TiO4 Gas Sensor to Propanol at Room Temperature

Directory of Open Access Journals (Sweden)

Ibrahim Gaidan

2017-08-01

Full Text Available In this study, three different compositions of ZnO and TiO2 powders were cold compressed and then heated at 1250 °C for five hours. The samples were ground to powder form. The powders were mixed with 5 wt % of polyvinyl butyral (PVB as binder and 1.5 wt % carbon black and ethylene-glyco-lmono-butyl-ether as a solvent to form screen-printed pastes. The prepared pastes were screen printed on the top of alumina substrates containing arrays of three copper electrodes. The three fabricated sensors were tested to detect propanol at room temperature at two different concentration ranges. The first concentration range was from 500 to 3000 ppm while the second concentration range was from 2500 to 5000 ppm, with testing taking place in steps of 500 ppm. The response of the sensors was found to increase monotonically in response to the increment in the propanol concentration. The surface morphology and chemical composition of the prepared samples were characterized by Scanning Electron Microscopy (SEM and X-Ray Diffraction (XRD. The sensors displayed good sensitivity to propanol vapors at room temperature. Operation under room-temperature conditions make these sensors novel, as other metal oxide sensors operate only at high temperature.

Design and development of DC high current sensor using Hall-Effect method

Science.gov (United States)

Dewi, Sasti Dwi Tungga; Panatarani, C.; Joni, I. Made

2016-02-01

This paper report a newly developed high DC current sensor by using a Hall effect method and also the measurement system. The Hall effect sensor receive the magnetic field generated by a current carrying conductor wire. The SS49E (Honeywell) magnetoresistive sensor was employed to sense the magnetic field from the field concentrator. The voltage received from SS49E then converted into digital by using analog to digital converter (ADC-10 bit). The digital data then processed in the microcontroller to be displayed as the value of the electric current in the LCD display. In addition the measurement was interfaced into Personal Computer (PC) using the communication protocols of RS232 which was finally displayed in real-time graphical form on the PC display. The performance test on the range ± 40 Ampere showed that the maximum relative error is 5.26%. It is concluded that the sensors and the measurement system worked properly according to the design with acceptable accuracy.

Organic Thin-Film Transistor (OTFT-Based Sensors

Directory of Open Access Journals (Sweden)

Daniel Elkington

2014-04-01

Full Text Available Organic thin film transistors have been a popular research topic in recent decades and have found applications from flexible displays to disposable sensors. In this review, we present an overview of some notable articles reporting sensing applications for organic transistors with a focus on the most recent publications. In particular, we concentrate on three main types of organic transistor-based sensors: biosensors, pressure sensors and “e-nose”/vapour sensors.

3D display considerations for rugged airborne environments

Science.gov (United States)

Barnidge, Tracy J.; Tchon, Joseph L.

2015-05-01

The KC-46 is the next generation, multi-role, aerial refueling tanker aircraft being developed by Boeing for the United States Air Force. Rockwell Collins has developed the Remote Vision System (RVS) that supports aerial refueling operations under a variety of conditions. The system utilizes large-area, high-resolution 3D displays linked with remote sensors to enhance the operator's visual acuity for precise aerial refueling control. This paper reviews the design considerations, trade-offs, and other factors related to the selection and ruggedization of the 3D display technology for this military application.

Ground water and earthquakes

Energy Technology Data Exchange (ETDEWEB)

Ts' ai, T H

1977-11-01

Chinese folk wisdom has long seen a relationship between ground water and earthquakes. Before an earthquake there is often an unusual change in the ground water level and volume of flow. Changes in the amount of particulate matter in ground water as well as changes in color, bubbling, gas emission, and noises and geysers are also often observed before earthquakes. Analysis of these features can help predict earthquakes. Other factors unrelated to earthquakes can cause some of these changes, too. As a first step it is necessary to find sites which are sensitive to changes in ground stress to be used as sensor points for predicting earthquakes. The necessary features are described. Recording of seismic waves of earthquake aftershocks is also an important part of earthquake predictions.

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.

Preparatory research to develop an operational method to calibrate airborne sensor data using a network of ground calibration sites

International Nuclear Information System (INIS)

Milton, E.J.; Smith, G.M.; Lawless, K.P.

1996-01-01

The objective of the research is to develop an operational method to convert airborne spectral radiance data to reflectance using a number of well-characterized ground calibration sites located around the UK. The study is in three phases. First, a pilot study has been conducted at a disused airfield in southern England to test the feasibility of the open-quote empirical line close-quote method of sensor calibration. The second phase is developing methods to predict temporal changes in the bidirectional reflectance of ground calibration sites. The final phase of the project will look at methods to extend such calibrations spatially. This paper presents some results from the first phase of this study. The viability of the empirical line method of correction is shown to depend upon the use of ground targets whose in-band reflectance encompasses that of the targets of interest in the spectral band(s) concerned. The experimental design for the second phase of the study, in which methods to predict temporal trends in the bidirectional reflectance of these sites will be developed, is discussed. Finally, it is planned to develop an automated method of searching through Landsat TM data for the UK to identify a number of candidate ground calibration sites for which the model can be tested. 11 refs., 5 figs., 5 tabs

Evaluation of ground water nutrient loading to Priest Lake, Bonner County, Idaho

International Nuclear Information System (INIS)

Freeman, K.M.; Ralston, D.R.

1994-01-01

The quality of water of Idaho lakes is of increasing concern, particularly when related to waste disposal and land use practices within the watersheds. This study investigates the Kalispell Bay and Granite Creek areas. Conclusions are as follows: Both areas demonstrate direction of ground water towards Priest Lake. The Kalispell Bay area displays horizontal ground water flow throughout the entire area with an upward hydraulic gradient over a portion of the area. The Granite Creek Area displays strictly horizontal flow; both study areas contain particular sub-areas which display nutrient enrichment, particulary nitrogen, of ground water; the granite Creek study area contains a sub-area displaying both elevated nitrogen concentrations and positive tests for E. coli bacteria. 2 figs., 2 tabs

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

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.

Applications of pressure-sensitive dielectric elastomer sensors

Science.gov (United States)

Böse, Holger; Ocak, Deniz; Ehrlich, Johannes

2016-04-01

Dielectric elastomer sensors for the measurement of compression loads with high sensitivity are described. The basic design of the sensors exhibits two profiled surfaces between which an elastomer film is confined. All components of the sensor were prepared with silicone whose stiffness can be varied in a wide range. Depending on details of the sensor design, various effects contribute to the enhancement of the capacitance. The intermediate elastomer film is stretched upon compression and electrode layers on the elastomer profiles and in the elastomer film approach each other. Different designs of the pressure sensor give rise to very different sensor characteristics in terms of the dependence of electric capacitance on compression force. Due to their inherent flexibility, the pressure sensors can be used on compliant substrates such as seats or beds or on the human body. This gives rise to numerous possible applications. The contribution describes also some examples of possible sensor applications. A glove was equipped with various sensors positioned at the finger tips. When grabbing an object with the glove, the sensors can detect the gripping forces of the individual fingers with high sensitivity. In a demonstrator of the glove equipped with seven sensors, the capacitances representing the gripping forces are recorded on a display. In another application example, a lower limb prosthesis was equipped with a pressure sensor to detect the load on the remaining part of the leg and the load is displayed in terms of the measured capacitance. The benefit of such sensors is to detect an eventual overload in order to prevent possible pressure sores. A third example introduces a seat load sensor system based on four extended pressure sensor mats. The sensor system detects the load distribution of a person on the seat. The examples emphasize the high performance of the new pressure sensor technology.

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.

Cow biological type affects ground beef colour stability.

Science.gov (United States)

Raines, Christopher R; Hunt, Melvin C; Unruh, John A

2009-12-01

To determine the effects of cow biological type on colour stability of ground beef, M. semimembranosus from beef-type (BSM) and dairy-type (DSM) cows was obtained 5d postmortem. Three blends (100% BSM, 50% BSM+50% DSM, 100% DSM) were adjusted to 90% and 80% lean points using either young beef trim (YBT) or beef cow trim (BCT), then packaged in high oxygen (High-O(2); 80% O(2)) modified atmosphere (MAP). The BSM+YBT patties had the brightest colour initially, but discoloured rapidly. Although DSM+BCT patties had the darkest colour initially, they discoloured least during display. Metmyoglobin reducing ability of ground DSM was up to fivefold greater than ground BSM, and TBARS values of BSM was twofold greater than DSM by the end of display (4d). Though initially darker than beef cow lean, dairy cow lean has a longer display colour life and may be advantageous to retailers using High-O(2) MAP.

Track classification within wireless sensor network

Science.gov (United States)

Doumerc, Robin; Pannetier, Benjamin; Moras, Julien; Dezert, Jean; Canevet, Loic

2017-05-01

In this paper, we present our study on track classification by taking into account environmental information and target estimated states. The tracker uses several motion model adapted to different target dynamics (pedestrian, ground vehicle and SUAV, i.e. small unmanned aerial vehicle) and works in centralized architecture. The main idea is to explore both: classification given by heterogeneous sensors and classification obtained with our fusion module. The fusion module, presented in his paper, provides a class on each track according to track location, velocity and associated uncertainty. To model the likelihood on each class, a fuzzy approach is used considering constraints on target capability to move in the environment. Then the evidential reasoning approach based on Dempster-Shafer Theory (DST) is used to perform a time integration of this classifier output. The fusion rules are tested and compared on real data obtained with our wireless sensor network.In order to handle realistic ground target tracking scenarios, we use an autonomous smart computer deposited in the surveillance area. After the calibration step of the heterogeneous sensor network, our system is able to handle real data from a wireless ground sensor network. The performance of this system is evaluated in a real exercise for intelligence operation ("hunter hunt" scenario).

Lower region: a new cue for figure-ground assignment.

Science.gov (United States)

Vecera, Shaun P; Vogel, Edward K; Woodman, Geoffrey F

2002-06-01

Figure-ground assignment is an important visual process; humans recognize, attend to, and act on figures, not backgrounds. There are many visual cues for figure-ground assignment. A new cue to figure-ground assignment, called lower region, is presented: Regions in the lower portion of a stimulus array appear more figurelike than regions in the upper portion of the display. This phenomenon was explored, and it was demonstrated that the lower-region preference is not influenced by contrast, eye movements, or voluntary spatial attention. It was found that the lower region is defined relative to the stimulus display, linking the lower-region preference to pictorial depth perception cues. The results are discussed in terms of the environmental regularities that this new figure-ground cue may reflect.

Bioinspired optical sensors for unmanned aerial systems

Science.gov (United States)

Chahl, Javaan; Rosser, Kent; Mizutani, Akiko

2011-04-01

Insects are dependant on the spatial, spectral and temporal distributions of light in the environment for flight control and navigation. This paper reports on flight trials of implementations of insect inspired behaviors on unmanned aerial vehicles. Optical flow methods for maintaining a constant height above ground and a constant course have been demonstrated to provide navigation capabilities that are impossible using conventional avionics sensors. Precision control of height above ground and ground course were achieved over long distances. Other vision based techniques demonstrated include a biomimetic stabilization sensor that uses the ultraviolet and green bands of the spectrum, and a sky polarization compass. Both of these sensors were tested over long trajectories in different directions, in each case showing performance similar to low cost inertial heading and attitude systems. The behaviors demonstrate some of the core functionality found in the lower levels of the sensorimotor system of flying insects and shows promise for more integrated solutions in the future.

Thermophysical Properties Along Curiosity's Traverse in Gale Crater, Mars, Derived from the REMS Ground Temperature Sensor

Science.gov (United States)

Vasavada, Ashwin R.; Piqueux, Sylvain; Lewis, Kevin W.; Lemmon, Mark T.; Smith, Michael Doyle

2016-01-01

The REMS instrument onboard the Mars Science Laboratory rover, Curiosity, has measured ground temperature nearly continuously at hourly intervals for two Mars years. Coverage of the entire diurnal cycle at 1 Hz is available every few martian days. We compare these measurements with predictions of surface atmosphere thermal models to derive the apparent thermal inertia and thermally derived albedo along the rovers traverse after accounting for the radiative effects of atmospheric water ice during fall and winter, as is necessary to match the measured seasonal trend. The REMS measurements can distinguish between active sand, other loose materials, mudstone, and sandstone based on their thermophysical properties. However, the apparent thermal inertias of bedrock dominated surfaces [approx. 350-550 J m(exp. -2) K(exp. -1 s(exp. -1/2 )] are lower than expected. We use rover imagery and the detailed shape of the diurnal ground temperature curve to explore whether lateral or vertical heterogeneity in the surface materials within the sensor footprint might explain the low inertias. We find that the bedrock component of the surface can have a thermal inertia as high as 650-1700 J m(exp. -2) K(exp. -1) s(exp. -1/2) for mudstone sites and approx. 700 J m(exp. -2) K(exp. -1) s(exp. - 1/2) for sandstone sites in models runs that include lateral and vertical mixing. Although the results of our forward modeling approach may be non-unique, they demonstrate the potential to extract information about lateral and vertical variations in thermophysical properties from temporally resolved measurements of ground temperature.

Retina-like sensor image coordinates transformation and display

Science.gov (United States)

Cao, Fengmei; Cao, Nan; Bai, Tingzhu; Song, Shengyu

2015-03-01

For a new kind of retina-like senor camera, the image acquisition, coordinates transformation and interpolation need to be realized. Both of the coordinates transformation and interpolation are computed in polar coordinate due to the sensor's particular pixels distribution. The image interpolation is based on sub-pixel interpolation and its relative weights are got in polar coordinates. The hardware platform is composed of retina-like senor camera, image grabber and PC. Combined the MIL and OpenCV library, the software program is composed in VC++ on VS 2010. Experience results show that the system can realizes the real-time image acquisition, coordinate transformation and interpolation.

Microstrip Patch Sensor for Salinity Determination.

Science.gov (United States)

Lee, Kibae; Hassan, Arshad; Lee, Chong Hyun; Bae, Jinho

2017-12-18

In this paper, a compact microstrip feed inset patch sensor is proposed for measuring the salinities in seawater. The working principle of the proposed sensor depends on the fact that different salinities in liquid have different relative permittivities and cause different resonance frequencies. The proposed sensor can obtain better sensitivity to salinity changes than common sensors using conductivity change, since the relative permittivity change to salinity is 2.5 times more sensitive than the conductivity change. The patch and ground plane of the proposed sensor are fabricated by conductive copper spray coating on the masks made by 3D printer. The fabricated patch and the ground plane are bonded to a commercial silicon substrate and then attached to 5 mm-high chamber made by 3D printer so that it contains only 1 mL seawater. For easy fabrication and testing, the maximum resonance frequency was selected under 3 GHz and to cover salinities in real seawater, it was assumed that the salinity changes from 20 to 35 ppt. The sensor was designed by the finite element method-based ANSYS high-frequency structure simulator (HFSS), and it can detect the salinity with 0.01 ppt resolution. The designed sensor has a resonance frequency separation of 37.9 kHz and reflection coefficients under -20 dB at the resonant frequencies. The fabricated sensor showed better performance with average frequency separation of 48 kHz and maximum reflection coefficient of -35 dB. By comparing with the existing sensors, the proposed compact and low-cost sensor showed a better detection capability. Therefore, the proposed patch sensor can be utilized in radio frequency (RF) tunable sensors for salinity determination.

Seismic Target Classification Using a Wavelet Packet Manifold in Unattended Ground Sensors Systems

Directory of Open Access Journals (Sweden)

Enliang Song

2013-07-01

Full Text Available One of the most challenging problems in target classification is the extraction of a robust feature, which can effectively represent a specific type of targets. The use of seismic signals in unattended ground sensor (UGS systems makes this problem more complicated, because the seismic target signal is non-stationary, geology-dependent and with high-dimensional feature space. This paper proposes a new feature extraction algorithm, called wavelet packet manifold (WPM, by addressing the neighborhood preserving embedding (NPE algorithm of manifold learning on the wavelet packet node energy (WPNE of seismic signals. By combining non-stationary information and low-dimensional manifold information, WPM provides a more robust representation for seismic target classification. By using a K nearest neighbors classifier on the WPM signature, the algorithm of wavelet packet manifold classification (WPMC is proposed. Experimental results show that the proposed WPMC can not only reduce feature dimensionality, but also improve the classification accuracy up to 95.03%. Moreover, compared with state-of-the-art methods, WPMC is more suitable for UGS in terms of recognition ratio and computational complexity.

Tethered Pyrotechnic Apparatus for Acquiring a Ground Sample

Science.gov (United States)

Jones, Jack; Zimmerman, Wayne; Wu, Jiunn Jenq; Badescu, Mircea; Sherrit, Stewart

2009-01-01

A proposed alternative design for the balloon-borne ground-sampling system described in the immediately preceding article would not rely on free fall to drive a harpoonlike sample-collecting device into the ground. Instead, the harpoon-like sample-collecting device would be a pyrotechnically driven, tethered projectile. The apparatus would include a tripod that would be tethered to the gondola. A gun for shooting the projectile into the ground would be mounted at the apex of the tripod. The gun would include an electronic trigger circuit, a chamber at the breech end containing a pyrotechnic charge, and a barrel. A sabot would be placed in the barrel just below the pyrotechnic charge, and the tethered projectile would be placed in the barrel just below the sabot. The tripod feet would be equipped with contact sensors connected to the trigger circuit. In operation, the tripod would be lowered to the ground on its tether. Once contact with the ground was detected by the sensors on all three tripod feet, the trigger circuit would fire the pyrotechnic charge to drive the projectile into the ground. (Requiring contact among all three tripod feet and the ground would ensure that the projectile would be fired into the ground, rather than up toward the gondola or the balloon.) The tethered projectile would then be reeled back up to the gondola for analysis of the sample.

An examination of OLED display application to military equipment

Science.gov (United States)

Thomas, J.; Lorimer, S.

2010-04-01

OLED display technology has developed sufficiently to support small format commercial applications such as cell-phone main display functions. Revenues seem sufficient to finance both performance improvements and to develop new applications. The situation signifies the possibility that OLED technology is on the threshold of credibility for military applications. This paper will examine both performance and some possible applications for the military ground mobile environment, identifying the advantages and disadvantages of this promising new technology.

Application of Optical Flow Sensors for Dead Reckoning, Heading Reference, Obstacle Detection, and Obstacle Avoidance

Science.gov (United States)

2015-09-01

motion tracking and one sensor for object detection in association with an Arduino microcontroller , we built an indoor ground robot capable of...one sensor for motion tracking and one sensor for object detection in association with an Arduino microcontroller , we built an indoor ground robot...the vehicle from the generated data delivered by the optical sensor to an Arduino microcontroller . The microcontroller controls the speed, heading

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.

Microstrip Patch Sensor for Salinity Determination

Directory of Open Access Journals (Sweden)

Kibae Lee

2017-12-01

Full Text Available In this paper, a compact microstrip feed inset patch sensor is proposed for measuring the salinities in seawater. The working principle of the proposed sensor depends on the fact that different salinities in liquid have different relative permittivities and cause different resonance frequencies. The proposed sensor can obtain better sensitivity to salinity changes than common sensors using conductivity change, since the relative permittivity change to salinity is 2.5 times more sensitive than the conductivity change. The patch and ground plane of the proposed sensor are fabricated by conductive copper spray coating on the masks made by 3D printer. The fabricated patch and the ground plane are bonded to a commercial silicon substrate and then attached to 5 mm-high chamber made by 3D printer so that it contains only 1 mL seawater. For easy fabrication and testing, the maximum resonance frequency was selected under 3 GHz and to cover salinities in real seawater, it was assumed that the salinity changes from 20 to 35 ppt. The sensor was designed by the finite element method-based ANSYS high-frequency structure simulator (HFSS, and it can detect the salinity with 0.01 ppt resolution. The designed sensor has a resonance frequency separation of 37.9 kHz and reflection coefficients under −20 dB at the resonant frequencies. The fabricated sensor showed better performance with average frequency separation of 48 kHz and maximum reflection coefficient of −35 dB. By comparing with the existing sensors, the proposed compact and low-cost sensor showed a better detection capability. Therefore, the proposed patch sensor can be utilized in radio frequency (RF tunable sensors for salinity determination.

Low Power and High Sensitivity MOSFET-Based Pressure Sensor

International Nuclear Information System (INIS)

Zhang Zhao-Hua; Ren Tian-Ling; Zhang Yan-Hong; Han Rui-Rui; Liu Li-Tian

2012-01-01

Based on the metal-oxide-semiconductor field effect transistor (MOSFET) stress sensitive phenomenon, a low power MOSFET pressure sensor is proposed. Compared with the traditional piezoresistive pressure sensor, the present pressure sensor displays high performances on sensitivity and power consumption. The sensitivity of the MOSFET sensor is raised by 87%, meanwhile the power consumption is decreased by 20%. (cross-disciplinary physics and related areas of science and technology)

Spacesuit Data Display and Management System

Science.gov (United States)

Hall, David G.; Sells, Aaron; Shah, Hemal

2009-01-01

A prototype embedded avionics system has been designed for the next generation of NASA extra-vehicular-activity (EVA) spacesuits. The system performs biomedical and other sensor monitoring, image capture, data display, and data transmission. An existing NASA Phase I and II award winning design for an embedded computing system (ZIN vMetrics - BioWATCH) has been modified. The unit has a reliable, compact form factor with flexible packaging options. These innovations are significant, because current state-of-the-art EVA spacesuits do not provide capability for data displays or embedded data acquisition and management. The Phase 1 effort achieved Technology Readiness Level 4 (high fidelity breadboard demonstration). The breadboard uses a commercial-grade field-programmable gate array (FPGA) with embedded processor core that can be upgraded to a space-rated device for future revisions.

Optimized Autonomous Space In-situ Sensor-Web for volcano monitoring

Science.gov (United States)

Song, W.-Z.; Shirazi, B.; Kedar, S.; Chien, S.; Webb, F.; Tran, D.; Davis, A.; Pieri, D.; LaHusen, R.; Pallister, J.; Dzurisin, D.; Moran, S.; Lisowski, M.

2008-01-01

In response to NASA's announced requirement for Earth hazard monitoring sensor-web technology, a multidisciplinary team involving sensor-network experts (Washington State University), space scientists (JPL), and Earth scientists (USGS Cascade Volcano Observatory (CVO)), is developing a prototype dynamic and scaleable hazard monitoring sensor-web and applying it to volcano monitoring. The combined Optimized Autonomous Space -In-situ Sensor-web (OASIS) will have two-way communication capability between ground and space assets, use both space and ground data for optimal allocation of limited power and bandwidth resources on the ground, and use smart management of competing demands for limited space assets. It will also enable scalability and seamless infusion of future space and in-situ assets into the sensor-web. The prototype will be focused on volcano hazard monitoring at Mount St. Helens, which has been active since October 2004. The system is designed to be flexible and easily configurable for many other applications as well. The primary goals of the project are: 1) integrating complementary space (i.e., Earth Observing One (EO-1) satellite) and in-situ (ground-based) elements into an interactive, autonomous sensor-web; 2) advancing sensor-web power and communication resource management technology; and 3) enabling scalability for seamless infusion of future space and in-situ assets into the sensor-web. To meet these goals, we are developing: 1) a test-bed in-situ array with smart sensor nodes capable of making autonomous data acquisition decisions; 2) efficient self-organization algorithm of sensor-web topology to support efficient data communication and command control; 3) smart bandwidth allocation algorithms in which sensor nodes autonomously determine packet priorities based on mission needs and local bandwidth information in real-time; and 4) remote network management and reprogramming tools. The space and in-situ control components of the system will be

Advancing Unmanned Aircraft Sensor Collection and Communication Capabilities with Optical Communications

Science.gov (United States)

Lukaczyk, T.

2015-12-01

Unmanned aircraft systems (UAS) are now being used for monitoring climate change over both land and seas. Their uses include monitoring of cloud conditions and atmospheric composition of chemicals and aerosols due to pollution, dust storms, fires, volcanic activity and air-sea fluxes. Additional studies of carbon flux are important for various ecosystem studies of both marine and terrestrial environments specifically, and can be related to climate change dynamics. Many measurements are becoming more complex as additional sensors become small enough to operate on more widely available small UAS. These include interferometric radars as well as scanning and fan-beam lidar systems which produce data streams even greater than those of high resolution video. These can be used to precisely map surfaces of the earth, ocean or ice features that are important for a variety of earth system studies. As these additional sensor capabilities are added to UAS the ability to transmit data back to ground or ship monitoring sites is limited by traditional wireless communication protocols. We describe results of tests of optical communication systems that provide significantly greater communication bandwidths for UAS, and discuss both the bandwidth and effective range of these systems, as well as their power and weight requirements both for systems on UAS, as well as those of ground-based receiver stations. We justify our additional use of Delay and Disruption Tolerant Networking (DTN) communication protocols with optical communication methods to ensure security and continuity of command and control operations. Finally, we discuss the implications for receiving, geo-referencing, archiving and displaying data streams from sensors communicated via optical communication to better enable real-time anomaly detection and adaptive sampling capabilities using multiple UAS or other unmanned or manned systems.

Distributed sensor management for space situational awareness via a negotiation game

Science.gov (United States)

Jia, Bin; Shen, Dan; Pham, Khanh; Blasch, Erik; Chen, Genshe

2015-05-01

Space situational awareness (SSA) is critical to many space missions serving weather analysis, communications, and navigation. However, the number of sensors used in space situational awareness is limited which hinders collision avoidance prediction, debris assessment, and efficient routing. Hence, it is critical to use such sensor resources efficiently. In addition, it is desired to develop the SSA sensor management algorithm in a distributed manner. In this paper, a distributed sensor management approach using the negotiation game (NG-DSM) is proposed for the SSA. Specifically, the proposed negotiation game is played by each sensor and its neighboring sensors. The bargaining strategies are developed for each sensor based on negotiating for accurately tracking desired targets (e.g., satellite, debris, etc.) . The proposed NG-DSM method is tested in a scenario which includes eight space objects and three different sensor modalities which include a space based optical sensor, a ground radar, or a ground Electro-Optic sensor. The geometric relation between the sensor, the Sun, and the space object is also considered. The simulation results demonstrate the effectiveness of the proposed NG-DSM sensor management methods, which facilitates an application of multiple-sensor multiple-target tracking for space situational awareness.

The Contribution of GIS to Display and Analyze the Water Quality Data Collected by a Wireless Sensor Network: Case of Bouregreg Catchment, Morocco

Science.gov (United States)

Boubakri, S.; Rhinane, H.

2017-11-01

The monitoring of water quality is, in most cases, managed in the laboratory and not on real time bases. Besides this process being lengthy, it doesn't provide the required specifications to describe the evolution of the quality parameters that are of interest. This study presents the integration of Geographic Information Systems (GIS) with wireless sensor networks (WSN) aiming to create a system able to detect the parameters like temperature, salinity and conductivity in a Moroccan catchment scale and transmit information to the support station. This Information is displayed and evaluated in a GIS using maps and spatial dashboard to monitor the water quality in real time.

THE CONTRIBUTION OF GIS TO DISPLAY AND ANALYZE THE WATER QUALITY DATA COLLECTED BY A WIRELESS SENSOR NETWORK: CASE OF BOUREGREG CATCHMENT, MOROCCO

Directory of Open Access Journals (Sweden)

S. Boubakri

2017-11-01

Full Text Available The monitoring of water quality is, in most cases, managed in the laboratory and not on real time bases. Besides this process being lengthy, it doesn’t provide the required specifications to describe the evolution of the quality parameters that are of interest. This study presents the integration of Geographic Information Systems (GIS with wireless sensor networks (WSN aiming to create a system able to detect the parameters like temperature, salinity and conductivity in a Moroccan catchment scale and transmit information to the support station. This Information is displayed and evaluated in a GIS using maps and spatial dashboard to monitor the water quality in real time.

Autonomous Sensors for Large Scale Data Collection

Science.gov (United States)

Noto, J.; Kerr, R.; Riccobono, J.; Kapali, S.; Migliozzi, M. A.; Goenka, C.

2017-12-01

Presented here is a novel implementation of a "Doppler imager" which remotely measures winds and temperatures of the neutral background atmosphere at ionospheric altitudes of 87-300Km and possibly above. Incorporating both recent optical manufacturing developments, modern network awareness and the application of machine learning techniques for intelligent self-monitoring and data classification. This system achieves cost savings in manufacturing, deployment and lifetime operating costs. Deployed in both ground and space-based modalities, this cost-disruptive technology will allow computer models of, ionospheric variability and other space weather models to operate with higher precision. Other sensors can be folded into the data collection and analysis architecture easily creating autonomous virtual observatories. A prototype version of this sensor has recently been deployed in Trivandrum India for the Indian Government. This Doppler imager is capable of operation, even within the restricted CubeSat environment. The CubeSat bus offers a very challenging environment, even for small instruments. The lack of SWaP and the challenging thermal environment demand development of a new generation of instruments; the Doppler imager presented is well suited to this environment. Concurrent with this CubeSat development is the development and construction of ground based arrays of inexpensive sensors using the proposed technology. This instrument could be flown inexpensively on one or more CubeSats to provide valuable data to space weather forecasters and ionospheric scientists. Arrays of magnetometers have been deployed for the last 20 years [Alabi, 2005]. Other examples of ground based arrays include an array of white-light all sky imagers (THEMIS) deployed across Canada [Donovan et al., 2006], oceans sensors on buoys [McPhaden et al., 2010], and arrays of seismic sensors [Schweitzer et al., 2002]. A comparable array of Doppler imagers can be constructed and deployed on the

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.

Low-Cost Ground Sensor Network for Intrusion Detection

Science.gov (United States)

2017-09-01

their suitability to our research. 1. Wireless Sensor Networks The backend network infrastructure forms the communication links for the network...were not ideal as they were perpetually turned on. Our research considered the backend communication infrastructure and its power requirements when...7 3. Border Patrol— Mobile Situation Awareness Tool (MSAT

Integrated multimodal human-computer interface and augmented reality for interactive display applications

Science.gov (United States)

Vassiliou, Marius S.; Sundareswaran, Venkataraman; Chen, S.; Behringer, Reinhold; Tam, Clement K.; Chan, M.; Bangayan, Phil T.; McGee, Joshua H.

2000-08-01

We describe new systems for improved integrated multimodal human-computer interaction and augmented reality for a diverse array of applications, including future advanced cockpits, tactical operations centers, and others. We have developed an integrated display system featuring: speech recognition of multiple concurrent users equipped with both standard air- coupled microphones and novel throat-coupled sensors (developed at Army Research Labs for increased noise immunity); lip reading for improving speech recognition accuracy in noisy environments, three-dimensional spatialized audio for improved display of warnings, alerts, and other information; wireless, coordinated handheld-PC control of a large display; real-time display of data and inferences from wireless integrated networked sensors with on-board signal processing and discrimination; gesture control with disambiguated point-and-speak capability; head- and eye- tracking coupled with speech recognition for 'look-and-speak' interaction; and integrated tetherless augmented reality on a wearable computer. The various interaction modalities (speech recognition, 3D audio, eyetracking, etc.) are implemented a 'modality servers' in an Internet-based client-server architecture. Each modality server encapsulates and exposes commercial and research software packages, presenting a socket network interface that is abstracted to a high-level interface, minimizing both vendor dependencies and required changes on the client side as the server's technology improves.

The role of unattended ground sensors (UGS) in regional confidence building and arms control

Energy Technology Data Exchange (ETDEWEB)

Vannoni, M.; Duggan, R.

1997-03-01

Although the Cold War has ended, the world has not become more peaceful. Without the stability provided by an international system dominated by two super-powers, local conflicts are more likely to escalate. Agreements to counter destabilizing pressures in regional conflicts can benefit from the use of cooperative monitoring. Cooperative monitoring is the collecting, analyzing, and sharing of information among parties to an agreement. Ground sensor technologies can contribute to the collection of relevant information. If implemented with consideration for local conditions, cooperative monitoring can build confidence, strengthen existing agreements, and set the stage for continued progress. This presentation describes two examples: the Israeli-Egyptian Sinai agreements of the 1970s and a conceptual example for the contemporary Korean Peninsula. The Sinai was a precedent for the successful use of UGS within the context of cooperative monitoring. The Korean Peninsula is the world`s largest military confrontation. Future confidence building measures that address the security needs of both countries could decrease the danger of conflict and help create an environment for a peace agreement.

Detection of premature browning in ground beef with an integrated optical-fibre based sensor using reflection spectroscopy and fibre Bragg grating technology

International Nuclear Information System (INIS)

O'Farrell, M; Sheridan, C; Lewis, E

2007-01-01

This paper reports on an optical fibre based sensor system to detect the occurrence of premature browning in ground beef. Premature browning (PMB) occurs when, at a temperature below the pasteurisation temperature of 71 deg. C, there are no traces of pink meat left in the patty. PMB is more frequent if poorer quality beef or beef that has been stored under imperfect conditions. The experimental work pertaining to this paper involved cooking fresh meat and meat that has been stored in a freezer for, 1 week, 1 month and 3 months and recording the reflected spectra and temperature at the core of the product, during the cooking process, in order to develop a classifier based on the spectral response and using a Self-Organising Map (SOM) to classify the patties into one of four categories, based on their colour. Further tests were also carried out on developing an all-optical fibre sensor for measuring both the temperature and colour in a single integrated probe. The integrated probe contains two different sensor concepts, one to monitor temperature, based on Fibre Bragg Grating (FBG) technology and a second for meat quality, based on reflection spectroscopy in the visible wavelength range

Graded effects in hierarchical figure-ground organization: reply to Peterson (1999).

Science.gov (United States)

Vecera, S P; O'Reilly, R C

2000-06-01

An important issue in vision research concerns the order of visual processing. S. P. Vecera and R. C. O'Reilly (1998) presented an interactive, hierarchical model that placed figure-ground segregation prior to object recognition. M. A. Peterson (1999) critiqued this model, arguing that because it used ambiguous stimulus displays, figure-ground processing did not precede object processing. In the current article, the authors respond to Peterson's (1999) interpretation of ambiguity in the model and her interpretation of what it means for figure-ground processing to come before object recognition. The authors argue that complete stimulus ambiguity is not critical to the model and that figure-ground precedes object recognition architecturally in the model. The arguments are supported with additional simulation results and an experiment, demonstrating that top-down inputs can influence figure-ground organization in displays that contain stimulus cues.

Hydrogen Leak Detection Sensor Database

Science.gov (United States)

Baker, Barton D.

2010-01-01

This slide presentation reviews the characteristics of the Hydrogen Sensor database. The database is the result of NASA's continuing interest in and improvement of its ability to detect and assess gas leaks in space applications. The database specifics and a snapshot of an entry in the database are reviewed. Attempts were made to determine the applicability of each of the 65 sensors for ground and/or vehicle use.

Generation of Ground Truth Datasets for the Analysis of 3d Point Clouds in Urban Scenes Acquired via Different Sensors

Science.gov (United States)

Xu, Y.; Sun, Z.; Boerner, R.; Koch, T.; Hoegner, L.; Stilla, U.

2018-04-01

In this work, we report a novel way of generating ground truth dataset for analyzing point cloud from different sensors and the validation of algorithms. Instead of directly labeling large amount of 3D points requiring time consuming manual work, a multi-resolution 3D voxel grid for the testing site is generated. Then, with the help of a set of basic labeled points from the reference dataset, we can generate a 3D labeled space of the entire testing site with different resolutions. Specifically, an octree-based voxel structure is applied to voxelize the annotated reference point cloud, by which all the points are organized by 3D grids of multi-resolutions. When automatically annotating the new testing point clouds, a voting based approach is adopted to the labeled points within multiple resolution voxels, in order to assign a semantic label to the 3D space represented by the voxel. Lastly, robust line- and plane-based fast registration methods are developed for aligning point clouds obtained via various sensors. Benefiting from the labeled 3D spatial information, we can easily create new annotated 3D point clouds of different sensors of the same scene directly by considering the corresponding labels of 3D space the points located, which would be convenient for the validation and evaluation of algorithms related to point cloud interpretation and semantic segmentation.

Networked Sensor Arrays

International Nuclear Information System (INIS)

Tighe, R. J.

2002-01-01

A set of independent radiation sensors, coupled with real-time data telemetry, offers the opportunity to run correlation algorithms for the sensor array as well as to incorporate non-radiological data into the system. This may enhance the overall sensitivity of the sensors and provide an opportunity to project the location of a source within the array. In collaboration with Lawrence Livermore National Laboratory (LLNL) and Sandia National Laboratories (SNL), we have conducted field experiments to test a prototype system. Combining the outputs of a set of distributed sensors permits the correlation that the independent sensor outputs. Combined with additional information such as traffic patterns and velocities, this can reduce random/false detections and enhance detection capability. The principle components of such a system include: (1) A set of radiation sensors. These may be of varying type and complexity, including gamma and/or neutron detectors, gross count and spectral-capable sensors, and low to high energy-resolution sensors. (2) A set of non-radiation sensors. These may include sensors such as vehicle presence and imaging sensors. (3) A communications architecture for near real-time telemetry. Depending upon existing infrastructure and bandwidth requirements, this may be a radio or hard-wire based system. (4) A central command console to pole the sensors, correlate their output, and display the data in a meaningful form to the system operator. Both sensitivity and selectivity are important considerations when evaluating the performance of a detection system. Depending on the application, the optimization of sensitivity as well as the rejection of ''nuisance'' radioactive sources may or may not be critical

Satellite and Ground-Based Sensors for the Urban Heat Island Analysis in the City of Rome

Directory of Open Access Journals (Sweden)

Roberto Fabrizi

2010-05-01

Full Text Available 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 to the layer of air closest to the surface. UHI spatial characteristics have been assessed using air temperatures measured by both weather stations and brightness temperature maps from the Advanced Along Track Scanning Radiometer (AATSR on board ENVISAT polar-orbiting satellite. In total, 634 daytime 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.

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.

On-Board Mining in the Sensor Web

Science.gov (United States)

Tanner, S.; Conover, H.; Graves, S.; Ramachandran, R.; Rushing, J.

2004-12-01

On-board data mining can contribute to many research and engineering applications, including natural hazard detection and prediction, intelligent sensor control, and the generation of customized data products for direct distribution to users. The ability to mine sensor data in real time can also be a critical component of autonomous operations, supporting deep space missions, unmanned aerial and ground-based vehicles (UAVs, UGVs), and a wide range of sensor meshes, webs and grids. On-board processing is expected to play a significant role in the next generation of NASA, Homeland Security, Department of Defense and civilian programs, providing for greater flexibility and versatility in measurements of physical systems. In addition, the use of UAV and UGV systems is increasing in military, emergency response and industrial applications. As research into the autonomy of these vehicles progresses, especially in fleet or web configurations, the applicability of on-board data mining is expected to increase significantly. Data mining in real time on board sensor platforms presents unique challenges. Most notably, the data to be mined is a continuous stream, rather than a fixed store such as a database. This means that the data mining algorithms must be modified to make only a single pass through the data. In addition, the on-board environment requires real time processing with limited computing resources, thus the algorithms must use fixed and relatively small amounts of processing time and memory. The University of Alabama in Huntsville is developing an innovative processing framework for the on-board data and information environment. The Environment for On-Board Processing (EVE) and the Adaptive On-board Data Processing (AODP) projects serve as proofs-of-concept of advanced information systems for remote sensing platforms. The EVE real-time processing infrastructure will upload, schedule and control the execution of processing plans on board remote sensors. These plans

Paradigm for expert display systems in nuclear plant and elsewhere

International Nuclear Information System (INIS)

Gabriel, J.R.

1986-02-01

Display of relevant data concerning plant operation has been a concern of the nuclear industry from its beginnings. Since the incident at Three Mile Island, this matter has had much careful scrutiny. L. Beltracchi, in particular, has originated a sequence of important steps to improve the operator's ability to recognize plant states and their changes. In the early 1980's, Beltracchi (1983, 1984) proposed a display based on the Rankine cycle for light water reactors. More recently, in an unpublished work (1986b), he described an extension that includes a small, rule-based system in the display program, drawing inferences about plant operation from sensor readings, and displaying those inferences on the Rankine display. Our paper examines Beltracchi's rule-based display from the perspective of knowledge bases. Earlier (Gabriel, 1983) we noted that analytical models of system behavior are just as much a knowledge base as are the rules of a conventional expert system. The problem of finding useful displays for a complex plant is discussed from this perspective. We then present a paradigm for developing designs with properties similar to those in Beltracchi's Rankine cycle display. Finally, to clarify the issue, we give a small example from an imaginary plant

Wireless Sensor Applications in Extreme Aeronautical Environments

Science.gov (United States)

Wilson, William C.; Atkinson, Gary M.

2013-01-01

NASA aeronautical programs require rigorous ground and flight testing. Many of the testing environments can be extremely harsh. These environments include cryogenic temperatures and high temperatures (greater than 1500 C). Temperature, pressure, vibration, ionizing radiation, and chemical exposure may all be part of the harsh environment found in testing. This paper presents a survey of research opportunities for universities and industry to develop new wireless sensors that address anticipated structural health monitoring (SHM) and testing needs for aeronautical vehicles. Potential applications of passive wireless sensors for ground testing and high altitude aircraft operations are presented. Some of the challenges and issues of the technology are also presented.

Discussing the theological grounds of moral principles.

Science.gov (United States)

Heller, Jan C

2005-01-01

Discussing the theological beliefs that ground Catholic moral principles can make some people uncomfortable, even while others will appreciate it. But these reactions will sometimes be revealed not as the emotions they are, but as objections to the relative independence or dependence of morality on foundational beliefs. In the end, context should dictate whether one displays the theological beliefs that ground Catholic moral principles.

Integrated Active Fire Retrievals and Biomass Burning Emissions Using Complementary Near-Coincident Ground, Airborne and Spaceborne Sensor Data

Science.gov (United States)

Schroeder, Wilfrid; Ellicott, Evan; Ichoku, Charles; Ellison, Luke; Dickinson, Matthew B.; Ottmar, Roger D.; Clements, Craig; Hall, Dianne; Ambrosia, Vincent; Kremens, Robert

2013-01-01

Ground, airborne and spaceborne data were collected for a 450 ha prescribed fire implemented on 18 October 2011 at the Henry W. Coe State Park in California. The integration of various data elements allowed near coincident active fire retrievals to be estimated. The Autonomous Modular Sensor-Wildfire (AMS) airborne multispectral imaging system was used as a bridge between ground and spaceborne data sets providing high quality reference information to support satellite fire retrieval error analyses and fire emissions estimates. We found excellent agreement between peak fire radiant heat flux data (less than 1% error) derived from near-coincident ground radiometers and AMS. Both MODIS and GOES imager active fire products were negatively influenced by the presence of thick smoke, which was misclassified as cloud by their algorithms, leading to the omission of fire pixels beneath the smoke, and resulting in the underestimation of their retrieved fire radiative power (FRP) values for the burn plot, compared to the reference airborne data. Agreement between airborne and spaceborne FRP data improved significantly after correction for omission errors and atmospheric attenuation, resulting in as low as 5 difference between AquaMODIS and AMS. Use of in situ fuel and fire energy estimates in combination with a collection of AMS, MODIS, and GOES FRP retrievals provided a fuel consumption factor of 0.261 kg per MJ, total energy release of 14.5 x 10(exp 6) MJ, and total fuel consumption of 3.8 x 10(exp 6) kg. Fire emissions were calculated using two separate techniques, resulting in as low as 15 difference for various species

Virtual Sensor Test Instrumentation, Phase II

Data.gov (United States)

National Aeronautics and Space Administration — Mobitrum has started the development of virtual sensor test instrumentation in Phase I for characterization and measurement of ground testing of propulsion systems....

On the ground state of Yang-Mills theory

OpenAIRE

Bakry, Ahmed S.; Leinweber, Derek B.; Williams, Anthony G.

2011-01-01

We investigate the overlap of the ground state meson potential with sets of mesonic-trial wave functions corresponding to different gluonic distributions. We probe the transverse structure of the flux tube through the creation of non-uniform smearing profiles for the string of glue connecting two color sources in Wilson loop operator. The non-uniformly UV-regulated flux-tube operators are found to optimize the overlap with the ground state and display interesting features in the ground state ...

On the ground state of Yang-Mills theory

Science.gov (United States)

Bakry, Ahmed S.; Leinweber, Derek B.; Williams, Anthony G.

2011-08-01

We investigate the overlap of the ground state meson potential with sets of mesonic-trial wave functions corresponding to different gluonic distributions. We probe the transverse structure of the flux tube through the creation of non-uniform smearing profiles for the string of glue connecting two color sources in Wilson loop operator. The non-uniformly UV-regulated flux-tube operators are found to optimize the overlap with the ground state and display interesting features in the ground state overlap.

The parameters of a sensor

International Nuclear Information System (INIS)

Neacsu, A.; Ciucu, C.

2004-01-01

The development of electronics and technology led to the development of high precision sensors. Generally all sensors are based on the inertia of a suspended mass which remains stationary with respect to the ground's movement. In the case of electromagnetic instruments, a coil is linked to the mass of a pendulum that moves in a magnetic field, creating an electric tension. In the case of this sensor, there is no need for a damper mechanism due to the fact that the damping force is produced by the currents induced in a copper plate oscillating in a strong magnetic field. In the experiment we determined the inner oscillating frequency and the damping factor of a sensor based on a mobile coil. (authors)

Wireless interrogation of passive antenna sensors

International Nuclear Information System (INIS)

Deshmukh, S; Huang, H

2010-01-01

Recently, we discovered that the resonant frequency of a microstrip patch antenna is sensitive to mechanical strains or crack presence in the ground plane. Based on this principle, antenna sensors have been demonstrated to measure strain and detect crack in metallic structures. This paper presents a wireless method to remotely interrogate a dual-frequency antenna sensor. An interrogation horn antenna was used to irradiate the antenna sensor with a linear chirp microwave signal. By implementing a light-activated switch at the sensor node and performing signal processing of the backscattered signals, the resonant frequencies of the antenna sensor along both polarizations can be measured remotely. Since the antenna sensor does not need a local power source and can be interrogated wirelessly, electric wiring can be eliminated. The sensor implementation, the signal processing and the experimental setup that validate the remote interrogation of the antenna sensor are presented. A power budget model has also been established to estimate the maximum interrogation range

Optimizing placements of ground-based snow sensors for areal snow cover estimation using a machine-learning algorithm and melt-season snow-LiDAR data

Science.gov (United States)

Oroza, C.; Zheng, Z.; Glaser, S. D.; Bales, R. C.; Conklin, M. H.

2016-12-01

We present a structured, analytical approach to optimize ground-sensor placements based on time-series remotely sensed (LiDAR) data and machine-learning algorithms. We focused on catchments within the Merced and Tuolumne river basins, covered by the JPL Airborne Snow Observatory LiDAR program. First, we used a Gaussian mixture model to identify representative sensor locations in the space of independent variables for each catchment. Multiple independent variables that govern the distribution of snow depth were used, including elevation, slope, and aspect. Second, we used a Gaussian process to estimate the areal distribution of snow depth from the initial set of measurements. This is a covariance-based model that also estimates the areal distribution of model uncertainty based on the independent variable weights and autocorrelation. The uncertainty raster was used to strategically add sensors to minimize model uncertainty. We assessed the temporal accuracy of the method using LiDAR-derived snow-depth rasters collected in water-year 2014. In each area, optimal sensor placements were determined using the first available snow raster for the year. The accuracy in the remaining LiDAR surveys was compared to 100 configurations of sensors selected at random. We found the accuracy of the model from the proposed placements to be higher and more consistent in each remaining survey than the average random configuration. We found that a relatively small number of sensors can be used to accurately reproduce the spatial patterns of snow depth across the basins, when placed using spatial snow data. Our approach also simplifies sensor placement. At present, field surveys are required to identify representative locations for such networks, a process that is labor intensive and provides limited guarantees on the networks' representation of catchment independent variables.

Downhole Applications of Magnetic Sensors.

Science.gov (United States)

Gooneratne, Chinthaka P; Li, Bodong; Moellendick, Timothy E

2017-10-19

In this paper we present a review of the application of two types of magnetic sensors-fluxgate magnetometers and nuclear magnetic resonance (NMR) sensors-in the oil/gas industry. These magnetic sensors play a critical role in drilling wells safely, accurately and efficiently into a target reservoir zone by providing directional data of the well and acquiring information about the surrounding geological formations. Research into magnetic sensors for oil/gas drilling has not been explored by researchers to the same extent as other applications, such as biomedical, magnetic storage and automotive/aerospace applications. Therefore, this paper aims to serve as an opportunity for researchers to truly understand how magnetic sensors can be used in a downhole environment and to provide fertile ground for research and development in this area. A look ahead, discussing other magnetic sensor technologies that can potentially be used in the oil/gas industry is presented, and what is still needed in order deploy them in the field is also addressed.

Advanced Sensors for Airborne Magnetic Measurements

National Research Council Canada - National Science Library

Bobb, L

2001-01-01

Numerous ground tests and platform tests were conducted to evaluate platform integration issues and the performance of the POLATOMIC 2000 magnetometer, a laser-pumped helium-4 total magnetic field sensor...

Small battery operated unattended radar sensor for security systems

Science.gov (United States)

Plummer, Thomas J.; Brady, Stephen; Raines, Robert

2013-06-01

McQ has developed, tested, and is supplying to Unattended Ground Sensor (UGS) customers a new radar sensor. This radar sensor is designed for short range target detection and classification. The design emphasis was to have low power consumption, totally automated operation, a very high probability of detection coupled with a very low false alarm rate, be able to locate and track targets, and have a price compatible with the UGS market. The radar sensor complements traditional UGS sensors by providing solutions for scenarios that are difficult for UGS. The design of this radar sensor and the testing are presented in this paper.

Sensors and Microsystems : AISEM 2011 Proceedings

CERN Document Server

Natale, Corrado; Mosiello, Lucia; Zappa, Giovanna

2012-01-01

This book contains a selection of papers presented at the 16th AISEM (“Associazione Italiana Sensori e Microsistemi”) National Conference on Sensors and Microsystems, held in Rome 7-9 February 2011. The conference highlighted updated results from both theoretical and applied research in the field of sensors and microsystems. This book presents material in an interdisciplinary approach, covering many aspects of the disciplines related to sensors and microsystems, including physics, chemistry, materials science, biology and applications. Provides a selection of the best papers from the most recent AISEM conference; Covers a broad range of topics relating to sensors and microsystems, including physics, chemistry, materials science, biology and applications; Offers interdisciplinary coverage, aimed at defining a common ground for sensors beyond the specific differences among the different particular implementation of sensors.              

A screen-printed flexible flow sensor

International Nuclear Information System (INIS)

Moschos, A; Kaltsas, G; Syrovy, T; Syrova, L

2017-01-01

A thermal flow sensor was printed on a flexible plastic substrate using exclusively screen-printing techniques. The presented device was implemented with custom made screen-printed thermistors, which allows simple, cost-efficient production on a variety of flexible substrates while maintaining the typical advantages of thermal flow sensors. Evaluation was performed for both static (zero flow) and dynamic conditions using a combination of electrical measurements and IR imaging techniques in order to determine important characteristics, such as temperature response, output repeatability, etc. The flow sensor was characterized utilizing the hot-wire and calorimetric principles of operation, while the preliminary results appear to be very promising, since the sensor was successfully evaluated and displayed adequate sensitivity in a relatively wide flow range. (paper)

Implicit memory for novel figure-ground displays includes a history of cross-border competition.

Science.gov (United States)

Peterson, Mary A; Lampignano, Daniel W

2003-08-01

When configural cues specify that a figure lies on opposite sides of a repeated border in prime andprobe shapes, probe latencies are longer than when prime and probe borders are unrelated. Do such results reflect negative priming for the shape of the prime ground or cross-border competition from figure memory? The present study tested these alternatives by adding partial closure as a competing cue and reducing the similarity between the prime ground and the shape of the probe. Results supported the cross-border competition interpretation. Additional findings were that partial closure is a configural cue and that response effects can emerge from the potential shape on the ground side of a border. One prior experience was sufficient for these effects.

Universal Smart Sensor Interface, Phase I

Data.gov (United States)

National Aeronautics and Space Administration — Ground testing of propulsion systems requires highly accurate and precise sensor systems. Setting up such systems can be more time consuming than the test. The...

1st National Conference on Sensors

CERN Document Server

D’Amico, Arnaldo; Natale, Corrado; Siciliano, Pietro; Seeber, Renato; Stefano, Luca; Bizzarri, Ranieri; Andò, Bruno

2014-01-01

This book contains a selection of papers presented at the First National Conference on Sensors held in Rome 15-17 February 2011. The conference highlighted state-of-the-art results from both theoretical and applied research in the field of sensors and related technologies. This book presents material in an interdisciplinary approach, covering many aspects of the disciplines related to sensors, including physics, chemistry, materials science, biology and applications.   ·         Provides a selection of the best papers from the First Italian National Conference on Sensors; ·         Covers a broad range of topics relating to sensors and microsystems, including physics, chemistry, materials science, biology and applications;       ·        Offers interdisciplinary coverage, aimed at defining a common ground for sensors beyond the specific differences among the different particular implementation of sensors.

2nd National Conference on Sensors

CERN Document Server

Baldini, Francesco; Natale, Corrado; Betta, Giovanni; Siciliano, Pietro

2015-01-01

This book contains a selection of papers presented at the Second National Conference on Sensors held in Rome 19-21 February 2014. The conference highlighted state-of-the-art results from both theoretical and applied research in the field of sensors and related technologies. This book presents material in an interdisciplinary approach, covering many aspects of the disciplines related to sensors, including physics, chemistry, materials science, biology and applications. ·         Provides a selection of the best papers from the Second Italian National Conference on Sensors; ·         Covers a broad range of topics relating to sensors and microsystems, including physics, chemistry, materials science, biology and applications; ·         Offers interdisciplinary coverage, aimed at defining a common ground for sensors beyond the specific differences among the different particular implementation of sensors.

Artificial intelligence enhancements to safety parameter display systems

International Nuclear Information System (INIS)

Hajek, B.K.; Hashemi, S.; Sharma, D.; Chandrasekaran, B.; Miller, D.W.

1986-01-01

Two prototype knowledge based systems have been developed at The Ohio State University to be the basis of an operator aid that can be attached to an existing nuclear power plant Safety Parameter Display System. The first system uses improved sensor validation techniques to provide input to a fault diagnosis process. The second system would use the diagnostic system output to synthesize corrective procedures to aid the control room licensed operator in plant recovery

Piezoresistive Soft Condensed Matter Sensor for Body-Mounted Vital Function Applications

Directory of Open Access Journals (Sweden)

Mark Melnykowycz

2016-03-01

Full Text Available A soft condensed matter sensor (SCMS designed to measure strains on the human body is presented. The hybrid material based on carbon black (CB and a thermoplastic elastomer (TPE was bonded to a textile elastic band and used as a sensor on the human wrist to measure hand motion by detecting the movement of tendons in the wrist. Additionally it was able to track the blood pulse wave of a person, allowing for the determination of pulse wave peaks corresponding to the systole and diastole blood pressures in order to calculate the heart rate. Sensor characterization was done using mechanical cycle testing, and the band sensor achieved a gauge factor of 4–6.3 while displaying low signal relaxation when held at a strain levels. Near-linear signal performance was displayed when loading to successively higher strain levels up to 50% strain.

A new pyrazoline-based fluorescent sensor for Al3+ in aqueous solution.

Science.gov (United States)

Hu, Shengli; Song, Jingjing; Wu, Gongying; Cheng, Cuixia; Gao, Qing

2015-02-05

A new pyrazoline-based fluorescent sensor was synthesized and the structure was confirmed by single crystal X-ray diffraction. The sensor responds to Al(3+) with high selectivity among a series of cations in aqueous methanol. This sensor forms a 1:1 complex with Al(3+) and displays fluorescent quenching. Copyright © 2014 Elsevier B.V. All rights reserved.

Emerging Needs for Pervasive Passive Wireless Sensor Networks on Aerospace Vehicles

Science.gov (United States)

Wilson, William C.; Juarez, Peter D.

2014-01-01

NASA is investigating passive wireless sensor technology to reduce instrumentation mass and volume in ground testing, air flight, and space exploration applications. Vehicle health monitoring systems (VHMS) are desired on all aerospace programs to ensure the safety of the crew and the vehicles. Pervasive passive wireless sensor networks facilitate VHMS on aerospace vehicles. Future wireless sensor networks on board aerospace vehicles will be heterogeneous and will require active and passive network systems. Since much has been published on active wireless sensor networks, this work will focus on the need for passive wireless sensor networks on aerospace vehicles. Several passive wireless technologies such as microelectromechanical systems MEMS, SAW, backscatter, and chipless RFID techniques, have all shown potential to meet the pervasive sensing needs for aerospace VHMS applications. A SAW VHMS application will be presented. In addition, application areas including ground testing, hypersonic aircraft and spacecraft will be explored along with some of the harsh environments found in aerospace applications.

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.

MicroSensors Systems: detection of a dismounted threat

Science.gov (United States)

Davis, Bill; Berglund, Victor; Falkofske, Dwight; Krantz, Brian

2005-05-01

The Micro Sensor System (MSS) is a layered sensor network with the goal of detecting dismounted threats approaching high value assets. A low power unattended ground sensor network is dependant on a network protocol for efficiency in order to minimize data transmissions after network establishment. The reduction of network 'chattiness' is a primary driver for minimizing power consumption and is a factor in establishing a low probability of detection and interception. The MSS has developed a unique protocol to meet these challenges. Unattended ground sensor systems are most likely dependant on batteries for power which due to size determines the ability of the sensor to be concealed after placement. To minimize power requirements, overcome size limitations, and maintain a low system cost the MSS utilizes advanced manufacturing processes know as Fluidic Self-Assembly and Chip Scale Packaging. The type of sensing element and the ability to sense various phenomenologies (particularly magnetic) at ranges greater than a few meters limits the effectiveness of a system. The MicroSensor System will overcome these limitations by deploying large numbers of low cost sensors, which is made possible by the advanced manufacturing process used in production of the sensors. The MSS program will provide unprecedented levels of real-time battlefield information which greatly enhances combat situational awareness when integrated with the existing Command, Control, Communications, Computers, Intelligence, Surveillance and Reconnaissance (C4ISR) infrastructure. This system will provide an important boost to realizing the information dominant, network-centric objective of Joint Vision 2020.

Shape Biased Low Power Spin Dependent Tunneling Magnetic Field Sensors

Science.gov (United States)

Tondra, Mark; Qian, Zhenghong; Wang, Dexin; Nordman, Cathy; Anderson, John

2001-10-01

Spin Dependent Tunneling (SDT) devices are leading candidates for inclusion in a number of Unattended Ground Sensor applications. Continued progress at NVE has pushed their performance to 1OOs of pT I rt. Hz 1 Hz. However, these sensors were designed to use an applied field from an on-chip coil to create an appropriate magnetic sensing configuration. The power required to generate this field (^100mW) is significantly greater than the power budget (^lmW) for a magnetic sensor in an Unattended Ground Sensor (UGS) application. Consequently, a new approach to creating an ideal sensing environment is required. One approach being used at NVE is "shape biasing." This means that the physical layout of the SDT sensing elements is such that the magnetization of the sensing film is correct even when no biasing field is applied. Sensors have been fabricated using this technique and show reasonable promise for UGS applications. Some performance trade-offs exist. The power is easily tinder 1 MW, but the sensitivity is typically lower by a factor of 10. This talk will discuss some of the design details of these sensors as well as their expected ultimate performance.

Lightning Sensors for Observing, Tracking and Nowcasting Severe Weather

Directory of Open Access Journals (Sweden)

Colin Price

2008-01-01

Full Text Available Severe and extreme weather is a major natural hazard all over the world, oftenresulting in major natural disasters such as hail storms, tornados, wind storms, flash floods,forest fires and lightning damages. While precipitation, wind, hail, tornados, turbulence,etc. can only be observed at close distances, lightning activity in these damaging stormscan be monitored at all spatial scales, from local (using very high frequency [VHF]sensors, to regional (using very low frequency [VLF] sensors, and even global scales(using extremely low frequency [ELF] sensors. Using sensors that detect the radio wavesemitted by each lightning discharge, it is now possible to observe and track continuouslydistant thunderstorms using ground networks of sensors. In addition to the number oflightning discharges, these sensors can also provide information on lightningcharacteristics such as the ratio between intra-cloud and cloud-to-ground lightning, thepolarity of the lightning discharge, peak currents, charge removal, etc. It has been shownthat changes in some of these lightning characteristics during thunderstorms are oftenrelated to changes in the severity of the storms. In this paper different lightning observingsystems are described, and a few examples are provided showing how lightning may beused to monitor storm hazards around the globe, while also providing the possibility ofsupplying short term forecasts, called nowcasting.

Calibration-free optical chemical sensors

Science.gov (United States)

DeGrandpre, Michael D.

2006-04-11

An apparatus and method for taking absorbance-based chemical measurements are described. In a specific embodiment, an indicator-based pCO2 (partial pressure of CO2) sensor displays sensor-to-sensor reproducibility and measurement stability. These qualities are achieved by: 1) renewing the sensing solution, 2) allowing the sensing solution to reach equilibrium with the analyte, and 3) calculating the response from a ratio of the indicator solution absorbances which are determined relative to a blank solution. Careful solution preparation, wavelength calibration, and stray light rejection also contribute to this calibration-free system. Three pCO2 sensors were calibrated and each had response curves which were essentially identical within the uncertainty of the calibration. Long-term laboratory and field studies showed the response had no drift over extended periods (months). The theoretical response, determined from thermodynamic characterization of the indicator solution, also predicted the observed calibration-free performance.

JERS-1 Workshop on the Ground Station for ASEAN

Science.gov (United States)

Peanvijarnpong, Chanchai

1990-11-01

Presented in viewgraph format, the present status of the ground station and future plan for utilizing earth observation satellites in Thailand is outlined. Topics addressed include: data acquisition system; operation status of LANDSAT, SPOT, and MOS-1 (Marine Observation Satellite-1); remote sensors of satellites; data output form; data correction level; data system in Thailand; ground station for MOS-1 satellite in Thailand; and future plan.

Graphene Chemical Sensor for Heliophysics Applications

Science.gov (United States)

Sultana, Mahmooda; Herrero, Fred; Khazanov, George

2013-01-01

Graphene is a single layer of carbon atoms that offer a unique set of advantages as a chemical sensor due to a number of its inherent properties. Graphene has been explored as a gas sensor for a variety of gases, and molecular sensitivity has been demonstrated by measuring the change in electrical properties due to the adsorption of target species. In this paper, we discuss the development of an array of chemical sensors based on graphene and its relevance to plasma physics due to its sensitivity to radical species such as oxonium, hydron and the corresponding neutrals. We briefly discuss the great impact such sensors will have on a number of heliophysics applications such as ground-based manifestations of space weather.

A 2.5D Map-Based Mobile Robot Localization via Cooperation of Aerial and Ground Robots.

Science.gov (United States)

Nam, Tae Hyeon; Shim, Jae Hong; Cho, Young Im

2017-11-25

Recently, there has been increasing interest in studying the task coordination of aerial and ground robots. When a robot begins navigation in an unknown area, it has no information about the surrounding environment. Accordingly, for robots to perform tasks based on location information, they need a simultaneous localization and mapping (SLAM) process that uses sensor information to draw a map of the environment, while simultaneously estimating the current location of the robot on the map. This paper aims to present a localization method based in cooperation between aerial and ground robots in an indoor environment. The proposed method allows a ground robot to reach accurate destination by using a 2.5D elevation map built by a low-cost RGB-D (Red Green and Blue-Depth) sensor and 2D Laser sensor attached onto an aerial robot. A 2.5D elevation map is formed by projecting height information of an obstacle using depth information obtained by the RGB-D sensor onto a grid map, which is generated by using the 2D Laser sensor and scan matching. Experimental results demonstrate the effectiveness of the proposed method for its accuracy in location recognition and computing speed.

A 2.5D Map-Based Mobile Robot Localization via Cooperation of Aerial and Ground Robots

Directory of Open Access Journals (Sweden)

Tae Hyeon Nam

2017-11-01

Full Text Available Recently, there has been increasing interest in studying the task coordination of aerial and ground robots. When a robot begins navigation in an unknown area, it has no information about the surrounding environment. Accordingly, for robots to perform tasks based on location information, they need a simultaneous localization and mapping (SLAM process that uses sensor information to draw a map of the environment, while simultaneously estimating the current location of the robot on the map. This paper aims to present a localization method based in cooperation between aerial and ground robots in an indoor environment. The proposed method allows a ground robot to reach accurate destination by using a 2.5D elevation map built by a low-cost RGB-D (Red Green and Blue-Depth sensor and 2D Laser sensor attached onto an aerial robot. A 2.5D elevation map is formed by projecting height information of an obstacle using depth information obtained by the RGB-D sensor onto a grid map, which is generated by using the 2D Laser sensor and scan matching. Experimental results demonstrate the effectiveness of the proposed method for its accuracy in location recognition and computing speed.

Robust site security using smart seismic array technology and multi-sensor data fusion

Science.gov (United States)

Hellickson, Dean; Richards, Paul; Reynolds, Zane; Keener, Joshua

2010-04-01

Traditional site security systems are susceptible to high individual sensor nuisance alarm rates that reduce the overall system effectiveness. Visual assessment of intrusions can be intensive and manually difficult as cameras are slewed by the system to non intrusion areas or as operators respond to nuisance alarms. Very little system intrusion performance data are available other than discrete sensor alarm indications that provide no real value. This paper discusses the system architecture, integration and display of a multi-sensor data fused system for wide area surveillance, local site intrusion detection and intrusion classification. The incorporation of a novel seismic array of smart sensors using FK Beamforming processing that greatly enhances the overall system detection and classification performance of the system is discussed. Recent test data demonstrates the performance of the seismic array within several different installations and its ability to classify and track moving targets at significant standoff distances with exceptional immunity to background clutter and noise. Multi-sensor data fusion is applied across a suite of complimentary sensors eliminating almost all nuisance alarms while integrating within a geographical information system to feed a visual-fusion display of the area being secured. Real-time sensor detection and intrusion classification data is presented within a visual-fusion display providing greatly enhanced situational awareness, system performance information and real-time assessment of intrusions and situations of interest with limited security operator involvement. This approach scales from a small local perimeter to very large geographical area and can be used across multiple sites controlled at a single command and control station.

Electrochemical Glucose Biosensor Based on Glucose Oxidase Displayed on Yeast Surface.

Science.gov (United States)

Wang, Hongwei; Lang, Qiaolin; Liang, Bo; Liu, Aihua

2015-01-01

The conventional enzyme-based biosensor requires chemical or physical immobilization of purified enzymes on electrode surface, which often results in loss of enzyme activity and/or fractions immobilized over time. It is also costly. A major advantage of yeast surface display is that it enables the direct utilization of whole cell catalysts with eukaryote-produced proteins being displayed on the cell surface, providing an economic alternative to traditional production of purified enzymes. Herein, we describe the details of the display of glucose oxidase (GOx) on yeast cell surface and its application in the development of electrochemical glucose sensor. In order to achieve a direct electrochemistry of GOx, the entire cell catalyst (yeast-GOx) was immobilized together with multiwalled carbon nanotubes on the electrode, which allowed sensitive and selective glucose detection.

Illuminant-adaptive color reproduction for mobile display

Science.gov (United States)

Kim, Jong-Man; Park, Kee-Hyon; Kwon, Oh-Seol; Cho, Yang-Ho; Ha, Yeong-Ho

2006-01-01

This paper proposes an illuminant-adaptive reproduction method using light adaptation and flare conditions for a mobile display. Mobile displays, such as PDAs and cellular phones, are viewed under various lighting conditions. In particular, images displayed in daylight are perceived as quite dark due to the light adaptation of the human visual system, as the luminance of a mobile display is considerably lower than that of an outdoor environment. In addition, flare phenomena decrease the color gamut of a mobile display by increasing the luminance of dark areas and de-saturating the chroma. Therefore, this paper presents an enhancement method composed of lightness enhancement and chroma compensation. First, the ambient light intensity is measured using a lux-sensor, then the flare is calculated based on the reflection ratio of the display device and the ambient light intensity. The relative cone response is nonlinear to the input luminance. This is also changed by the ambient light intensity. Thus, to improve the perceived image, the displayed luminance is enhanced by lightness linearization. In this paper, the image's luminance is transformed by linearization of the response to the input luminance according to the ambient light intensity. Next, the displayed image is compensated according to the physically reduced chroma, resulting from flare phenomena. The reduced chroma value is calculated according to the flare for each intensity. The chroma compensation method to maintain the original image's chroma is applied differently for each hue plane, as the flare affects each hue plane differently. At this time, the enhanced chroma also considers the gamut boundary. Based on experimental observations, the outer luminance-intensity generally ranges from 1,000 lux to 30,000 lux. Thus, in the case of an outdoor environment, i.e. greater than 1,000 lux, this study presents a color reproduction method based on an inverse cone response curve and flare condition. Consequently

On the ground state of Yang-Mills theory

International Nuclear Information System (INIS)

Bakry, Ahmed S.; Leinweber, Derek B.; Williams, Anthony G.

2011-01-01

Highlights: → The ground state overlap for sets of meson potential trial states is measured. → Non-uniform gluonic distributions are probed via Wilson loop operator. → The locally UV-regulated flux-tube operators can optimize the ground state overlap. - Abstract: We investigate the overlap of the ground state meson potential with sets of mesonic-trial wave functions corresponding to different gluonic distributions. We probe the transverse structure of the flux tube through the creation of non-uniform smearing profiles for the string of glue connecting two color sources in Wilson loop operator. The non-uniformly UV-regulated flux-tube operators are found to optimize the overlap with the ground state and display interesting features in the ground state overlap.

Infrared processing and sensor fusion for anti-personnel land-mine detection

NARCIS (Netherlands)

Schavemaker, J.G.M.; Cremer, F.; Schutte, K.; Breejen, E. den

2000-01-01

In this paper we present the results of infrared processing and sensor fusion obtained within the European research project GEODE (Ground Explosive Ordnance DEtection) that strives for the realization of a vehicle-mounted, multi-sensor anti-personnel land-mine detection system for humanitarian

Simulated monitor display for CCTV

International Nuclear Information System (INIS)

Steele, B.J.

1982-01-01

Two computer programs have been developed which generate a two-dimensional graphic perspective of the video output produced by a Closed Circuit Television (CCTV) camera. Both programs were primarily written to produce a graphic display simulating the field-of-view (FOV) of a perimeter assessment system as seen on a CCTV monitor. The original program was developed for use on a Tektronix 4054 desktop computer; however, the usefulness of this graphic display program led to the development of a similar program for a Hewlett-Packard 9845B desktop computer. After entry of various input parameters, such as, camera lens and orientation, the programs automatically calculate and graphically plot the locations of various items, e.g., fences, an assessment zone, running men, and intrusion detection sensors. Numerous special effects can be generated to simulate such things as roads, interior walls, or sides of buildings. Other objects can be digitized and entered into permanent memory similar to the running men. With this type of simulated monitor perspective, proposed camera locations with respect to fences and a particular assessment zone can be rapidly evaluated without the costly time delays and expenditures associated with field evaluation

The Rendezvous Monitoring Display Capabilities of the Rendezvous and Proximity Operations Program

Science.gov (United States)

Brazzel, Jack; Spehar, Pete; Clark, Fred; Foster, Chris; Eldridge, Erin

2013-01-01

The Rendezvous and Proximity Operations Program (RPOP) is a laptop computer- based relative navigation tool and piloting aid that was developed during the Space Shuttle program. RPOP displays a graphical representation of the relative motion between the target and chaser vehicles in a rendezvous, proximity operations and capture scenario. After being used in over 60 Shuttle rendezvous missions, some of the RPOP display concepts have become recognized as a minimum standard for cockpit displays for monitoring the rendezvous task. To support International Space Station (ISS) based crews in monitoring incoming visiting vehicles, RPOP has been modified to allow crews to compare the Cygnus visiting vehicle s onboard navigated state to processed range measurements from an ISS-based, crew-operated Hand Held Lidar sensor. This paper will discuss the display concepts of RPOP that have proven useful in performing and monitoring rendezvous and proximity operations.

Optical sensors for earth observation. Chikyu kansokuyo kogaku sensor

Energy Technology Data Exchange (ETDEWEB)

Ono, A [National Research Laboratory of Metrology, Tsukuba (Japan)

1991-10-10

Developments are made on an optical imager (ASTER) used to collect mainly images of land areas and an infrared sounder (IMG) to measure vertical air temperature distribution and vertical concentration distribution of specific gases, as satellite mounted sensors for earth observation. All the sensor characteristics of the ASTER comprising a visible near infrared radiometer, short wave infrared radiometer and thermal infrared radiometer are required to be capable of providing measurement, evaluation and assurance at the required accuracies during the entire life time. A problem to be solved is how to combine the on-ground calibration prior to launching, on-satellite calibration, and calibration between the test site and the sensors. The IMG is a Fourier transform spectroscopic infrared sounder, which is demanded of a high wave resolution over extended periods of time as well as a high radiation measuring capability. Also required are the level elevation of analysis algorithms to solve inverse problems from the observed radiation spectra, and the data base with high accuracy. 19 refs., 4 figs., 4 tabs.

An Assessment of Alternative Synthetic Aperture Radar Display Formats: Orientation and Situational Awareness

National Research Council Canada - National Science Library

Kuperman, Gilbert

1998-01-01

...) display of SAR overlaid on corresponding DTM data. Eight imagery analysts (IAs), assigned to the Israeli Ground Corps Command Imagery Analysis Unit and to the Israel Air Force, and two weapon system officers (WSOs...

Presentation of Various Tactile Sensations Using Micro-Needle Electrotactile Display.

Directory of Open Access Journals (Sweden)

Mayuko Tezuka

Full Text Available Tactile displays provoke tactile sensations by artificially stimulating tactile receptors. While many types of tactile displays have been developed, electrotactile displays that exploit electric stimulation can be designed to be thin, light, flexible and thus, wearable. However, the high voltages required to stimulate tactile receptors and limited varieties of possible sensations pose problems. In our previous work, we developed an electrotactile display using a micro-needle electrode array that can drastically reduce the required voltage by penetrating through the high-impedance stratum corneum painlessly, but displaying various tactile sensations was still a challenge. In this work, we demonstrate presentation of tactile sensation of different roughness to the subjects, which is enabled by the arrangement of the electrodes; the needle electrodes are on the fingertip and the ground electrode is on the fingernail. With this arrangement, the display can stimulate the tactile receptors that are located not only in the shallow regions of the finger but also those in the deep regions. It was experimentally revealed that the required voltage was further reduced compared to previous devices and that the roughness presented by the display was controlled by the pulse frequency and the switching time, or the stimulation flow rate. The proposed electrotactile display is readily applicable as a new wearable haptic device for advanced information communication technology.

Miniaturized optical sensors based on lens arrays

DEFF Research Database (Denmark)

Hanson, Steen Grüner; Jakobsen, M.L.; Larsen, H.E.

2005-01-01

A suite of optical sensors based on the use of lenticular arrays for probing mechanical deflections will be displayed. The optical systems are well suited for miniaturization, and utilize speckles as the information-carriers. This implementation allows for acquiring directional information...

Explosive Infrasonic Events: Sensor Comparison Experiment (SCE)

Energy Technology Data Exchange (ETDEWEB)

Schnurr, J. M. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Garces, M. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Rodgers, A. J. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

2017-02-06

SCE (sensor comparison experiment) 1 through 4 consists of a series of four controlled above-ground explosions designed to provide new data for overpressure propagation. Infrasound data were collected by LLNL iPhones and other sensors. Origin times, locations HOB, and yields are not being released at this time and are therefore not included in this report. This preliminary report will be updated as access to additional data changes, or instrument responses are determined.

Infrasound Sensor and Porous-Hose Filter Characterization Results

Science.gov (United States)

Hart, D. M.; Harris, J. M.

2008-12-01

The Ground-Based Nuclear Explosion Monitoring Research and Development (GNEM R&D) program at Sandia National Laboratories (SNL) is regarded as the primary center for unbiased expertise in testing and evaluation of geophysical sensors and instrumentation for nuclear explosion monitoring. Over the past year much of our work has focused in the area of infrasound sensor characterization through the continuing development of an infrasound sensor characterization test-bed. Our main areas of focus have been in new sensor characterization and understanding the effects of porous-hose filters for reducing acoustic background signals. Three infrasound sensors were evaluated for characteristics of instrument response, linearity and self-noise. The sensors tested were Chaparral Physics model 2.5 low-gain, New Mexico Tech All-Sensor and the Inter-Mountain Labs model SS avalanche sensor. For the infrasound sensors tested, the test results allow us to conclude that two of the three sensors had sufficiently quiet noise floor to be at or below the Acoustic low-noise model from 0.1 to 7 Hz, which make those sensors suitable to explosion monitoring. The other area of focus has been to understand the characteristics of porous-hose filters used at some monitoring sites. For this, an experiment was designed in which two infrasound sensors were co- located. One sensor was connected to a typical porous-hose spatial filter consisting of eight individual hoses covering a 30m aperture and the second sensor was left open to unimpeded acoustic input. Data were collected for several days, power spectrum computed for two-hour windows and the relative gain of the porous-hose filters were estimated by dividing the power spectrum. The porous-hose filter appears to attenuate less than 3 dB (rel 1 Pa**2/Hz) below 0.1 Hz and as much as 25 dB at 1 Hz and between 20 to 10 dB above 10 Hz. Several more experiments will be designed to address the effects of different characteristics of the individual porous

Time management displays for shuttle countdown

Science.gov (United States)

Beller, Arthur E.; Hadaller, H. Greg; Ricci, Mark J.

1992-01-01

The Intelligent Launch Decision Support System project is developing a Time Management System (TMS) for the NASA Test Director (NTD) to use for time management during Shuttle terminal countdown. TMS is being developed in three phases: an information phase; a tool phase; and an advisor phase. The information phase is an integrated display (TMID) of firing room clocks, of graphic timelines with Ground Launch Sequencer events, and of constraints. The tool phase is a what-if spreadsheet (TMWI) for devising plans for resuming from unplanned hold situations. It is tied to information in TMID, propagates constraints forward and backward to complete unspecified values, and checks the plan against constraints. The advisor phase is a situation advisor (TMSA), which proactively suggests tactics. A concept prototype for TMSA is under development. The TMID is currently undergoing field testing. Displays for TMID and TMWI are described. Descriptions include organization, rationale for organization, implementation choices and constraints, and use by NTD.

A Sentinel Sensor Network for Hydrogen Sensing

Directory of Open Access Journals (Sweden)

Andrew J. Mason

2003-02-01

Full Text Available A wireless sensor network is presented for in-situ monitoring of atmospheric hydrogen concentration. The hydrogen sensor network consists of multiple sensor nodes, equipped with titania nanotube hydrogen sensors, distributed throughout the area of interest; each node is both sensor, and data-relay station that enables extended wide area monitoring without a consequent increase of node power and thus node size. The hydrogen sensor is fabricated from a sheet of highly ordered titania nanotubes, made by anodization of a titanium thick film, to which platinum electrodes are connected. The electrical resistance of the hydrogen sensor varies from 245 Ω at 500 ppm hydrogen, to 10.23 kΩ at 0 ppm hydrogen (pure nitrogen environment. The measured resistance is converted to voltage, 0.049 V at 500 ppm to 2.046 V at 0 ppm, by interface circuitry. The microcontroller of the sensor node digitizes the voltage and transmits the digital information, using intermediate nodes as relays, to a host node that downloads measurement data to a computer for display. This paper describes the design and operation of the sensor network, the titania nanotube hydrogen sensors with an apparent low level resolution of approximately 0.05 ppm, and their integration in one widely useful device.

iShake: Mobile Phones as Seismic Sensors (Invited)

Science.gov (United States)

Dashti, S.; Reilly, J.; Bray, J. D.; Bayen, A. M.; Glaser, S. D.; Mari, E.

2010-12-01

Emergency responders must “see” the effects of an earthquake clearly and rapidly so that they can respond effectively to the damage it has produced. Great strides have been made recently in developing methodologies that deliver rapid and accurate post-earthquake information. However, shortcomings still exist. The iShake project is an innovative use of cell phones and information technology to bridge the gap between the high quality, but sparse, ground motion instrument data that are used to help develop ShakeMap and the low quality, but large quantity, human observational data collected to construct a “Did You Feel It?” (DYFI)-based map. Rather than using people as measurement “devices” as is being done through DYFI, the iShake project is using their cell phones to measure ground motion intensity parameters and automatically deliver the data to the U.S. Geological Survey (USGS) for processing and dissemination. In this participatory sensing paradigm, quantitative shaking data from numerous cellular phones will enable the USGS to produce shaking intensity maps more accurately than presently possible. The phone sensor, however, is an imperfect device with performance variations among phones of a given model as well as between models. The sensor is the entire phone, not just the micro-machined transducer inside. A series of 1-D and 3-D shaking table tests were performed at UC San Diego and UC Berkeley, respectively, to evaluate the performance of a class of cell phones. In these tests, seven iPhones and iPod Touch devices that were mounted at different orientations were subjected to 124 earthquake ground motions to characterize their response and reliability as seismic sensors. The testing also provided insight into the seismic response of unsecured and falling instruments. The cell phones measured seismic parameters such as peak ground acceleration (PGA), peak ground velocity (PGV), peak ground displacement (PGD), and 5% damped spectral accelerations well

Optical stimulator for vision-based sensors

DEFF Research Database (Denmark)

Rössler, Dirk; Pedersen, David Arge Klevang; Benn, Mathias

2014-01-01

We have developed an optical stimulator system for vision-based sensors. The stimulator is an efficient tool for stimulating a camera during on-ground testing with scenes representative of spacecraft flights. Such scenes include starry sky, planetary objects, and other spacecraft. The optical...

Flexible Sensors for Pressure Therapy: Effect of Substrate Curvature and Stiffness on Sensor Performance.

Science.gov (United States)

Khodasevych, Iryna; Parmar, Suresh; Troynikov, Olga

2017-10-20

Flexible pressure sensors are increasingly being used in medical and non-medical applications, and particularly in innovative health monitoring. Their efficacy in medical applications such as compression therapy depends on the accuracy and repeatability of their output, which in turn depend on factors such as sensor type, shape, pressure range, and conformability of the sensor to the body surface. Numerous researchers have examined the effects of sensor type and shape, but little information is available on the effect of human body parameters such as support surfaces' curvature and the stiffness of soft tissues on pressure sensing performance. We investigated the effects of body parameters on the performance of pressure sensors using a custom-made human-leg-like test setup. Pressure sensing parameters such as accuracy, drift and repeatability were determined in both static (eight hours continuous pressure) and dynamic (10 cycles of pressure application of 30 s duration) testing conditions. The testing was performed with a focus on compression therapy application for venous leg ulcer treatments, and was conducted in a low-pressure range of 20-70 mmHg. Commercially available sensors manufactured by Peratech and Sensitronics were used under various loading conditions to determine the influence of stiffness and curvature. Flat rigid, flat soft silicone and three cylindrical silicone surfaces of radii of curvature of 3.5 cm, 5.5 cm and 6.5 cm were used as substrates under the sensors. The Peratech sensor averaged 94% accuracy for both static and dynamic measurements on all substrates; the Sensitronics sensor averaged 88% accuracy. The Peratech sensor displayed moderate variations and the Sensitronics sensor large variations in output pressure readings depending on the underlying test surface, both of which were reduced markedly by individual pressure calibration for surface type. Sensor choice and need for calibration to surface type are important considerations for

REAL-TIME MONITORING SYSTEM USING UNMANNED AERIAL VEHICLE INTEGRATED WITH SENSOR OBSERVATION SERVICE

Directory of Open Access Journals (Sweden)

A. Witayangkurn

2012-09-01

Full Text Available The Unmanned Aerial Vehicle (UAV is an emerging technology being adapted for a wide range of applications. Real-time monitoring is essential to enhance the effectiveness of UAV applications. Sensor networks are networks constructed from various sensor nodes. International standard such as OGC's SOS (Sensor Observation Service makes it possible to share sensor data with other systems as well as to provide accessibility to globally distributed users. In this paper, we propose a system combining UAV technology and sensor network technology to use an UAV as a mobile node of sensor network so that the sensor data from UAV is published and shared real-time. A UAV can extend the observation range of a sensor network to remote areas where it is usually difficult to access such as disaster area. We constructed a UAV system using remote-controlled helicopter and various sensors such as GPS, gyrocompass, laser range finder, Digital camera and Thermometer. Furthermore, we extended the Sensor Observation Service (SOS and Sensor Service Grid (SSG to support mobile sensor nodes. Then, we conducted experiments of flying the helicopter over an area of the interest. During the flight, the system measured environmental data using its sensors and captured images of the ground. The data was sent to a SOS node as the ground station via Wi-Fi which was published using SSG to give real- time access to globally distributed users.

"Head up and eyes out" advances in head mounted displays capabilities

Science.gov (United States)

Cameron, Alex

2013-06-01

There are a host of helmet and head mounted displays, flooding the market place with displays which provide what is essentially a mobile computer display. What sets aviators HMDs apart is that they provide the user with accurate conformal information embedded in the pilots real world view (see through display) where the information presented is intuitive and easy to use because it overlays the real world (mix of sensor imagery, symbolic information and synthetic imagery) and enables them to stay head up, eyes out, - improving their effectiveness, reducing workload and improving safety. Such systems are an enabling technology in the provision of enhanced Situation Awareness (SA) and reducing user workload in high intensity situations. Safety Is Key; so the addition of these HMD functions cannot detract from the aircrew protection functions of conventional aircrew helmets which also include life support and audio communications. These capabilities are finding much wider application in new types of compact man mounted audio/visual products enabled by the emergence of new families of micro displays, novel optical concepts and ultra-compact low power processing solutions. This papers attempts to capture the key drivers and needs for future head mounted systems for aviation applications.

Estimating solar radiation using NOAA/AVHRR and ground measurement data

Science.gov (United States)

Fallahi, Somayeh; Amanollahi, Jamil; Tzanis, Chris G.; Ramli, Mohammad Firuz

2018-01-01

Solar radiation (SR) data are commonly used in different areas of renewable energy research. Researchers are often compelled to predict SR at ground stations for areas with no proper equipment. The objective of this study was to test the accuracy of the artificial neural network (ANN) and multiple linear regression (MLR) models for estimating monthly average SR over Kurdistan Province, Iran. Input data of the models were two data series with similar longitude, latitude, altitude, and month (number of months) data, but there were differences between the monthly mean temperatures in the first data series obtained from AVHRR sensor of NOAA satellite (DS1) and in the second data series measured at ground stations (DS2). In order to retrieve land surface temperature (LST) from AVHRR sensor, emissivity of the area was considered and for that purpose normalized vegetation difference index (NDVI) calculated from channels 1 and 2 of AVHRR sensor was utilized. The acquired results showed that the ANN model with DS1 data input with R2 = 0.96, RMSE = 1.04, MAE = 1.1 in the training phase and R2 = 0.96, RMSE = 1.06, MAE = 1.15 in the testing phase achieved more satisfactory performance compared with MLR model. It can be concluded that ANN model with remote sensing data has the potential to predict SR in locations with no ground measurement stations.

An Arduino project to record ground motion and to learn on earthquake hazard at high school

Science.gov (United States)

Saraò, Angela; Barnaba, Carla; Clocchiatti, Marco; Zuliani, David

2015-04-01

Through a multidisciplinary work that integrates Technology education with Earth Sciences, we implemented an educational program to raise the students' awareness of seismic hazard and to disseminate good practices of earthquake safety. Using free software and low-cost open hardware, the students of a senior class of the high school Liceo Paschini in Tolmezzo (NE Italy) implemented a seismograph using the Arduino open-source electronics platform and the ADXL345 sensors to emulate a low cost seismometer (e.g. O-NAVI sensor of the Quake-Catcher Network, http://qcn.stanford.edu). To accomplish their task the students were addressed to use the web resources for technical support and troubleshooting. Shell scripts, running on local computers under Linux OS, controlled the process of recording and display data. The main part of the experiment was documented using the DokuWiki style. Some propaedeutic lessons in computer sciences and electronics were needed to build up the necessary skills of the students and to fill in the gap of their background knowledge. In addition lectures by seismologists and laboratory activity allowed the class to exploit different aspects of the physics of the earthquake and particularly of the seismic waves, and to become familiar with the topics of seismic hazard through an inquiry-based learning. The Arduino seismograph achieved can be used for educational purposes and it can display tremors on the local network of the school. For sure it can record the ground motion due to a seismic event that can occur in the area, but further improvements are necessary for a quantitative analysis of the recorded signals.

Communications for unattended sensor networks

Science.gov (United States)

Nemeroff, Jay L.; Angelini, Paul; Orpilla, Mont; Garcia, Luis; DiPierro, Stefano

2004-07-01

The future model of the US Army's Future Combat Systems (FCS) and the Future Force reflects a combat force that utilizes lighter armor protection than the current standard. Survival on the future battlefield will be increased by the use of advanced situational awareness provided by unattended tactical and urban sensors that detect, identify, and track enemy targets and threats. Successful implementation of these critical sensor fields requires the development of advanced sensors, sensor and data-fusion processors, and a specialized communications network. To ensure warfighter and asset survivability, the communications must be capable of near real-time dissemination of the sensor data using robust, secure, stealthy, and jam resistant links so that the proper and decisive action can be taken. Communications will be provided to a wide-array of mission-specific sensors that are capable of processing data from acoustic, magnetic, seismic, and/or Chemical, Biological, Radiological, and Nuclear (CBRN) sensors. Other, more powerful, sensor node configurations will be capable of fusing sensor data and intelligently collect and process data images from infrared or visual imaging cameras. The radio waveform and networking protocols being developed under the Soldier Level Integrated Communications Environment (SLICE) Soldier Radio Waveform (SRW) and the Networked Sensors for the Future Force Advanced Technology Demonstration are part of an effort to develop a common waveform family which will operate across multiple tactical domains including dismounted soldiers, ground sensor, munitions, missiles and robotics. These waveform technologies will ultimately be transitioned to the JTRS library, specifically the Cluster 5 requirement.

Lightning-Sensor Data Help In Understanding Thunderstorms

Science.gov (United States)

Goodman, Steven J.

1992-01-01

NASA technical memorandum discusses research on use of data from network of ground-based magnetic direction-finding ground-strike lightning sensors to diagnose and predict occurrence and evolution of thunderstorms. Purposes of study to explore applicability and limitations of extrapolation techniques used to generate forecasts from data; to examine physically-based, nonlinear mathematical models for applicability to lightning-forecast problem; and to determine valid extrapolation ranges of such models for various weather scenarios.

Downhole Applications of Magnetic Sensors

Directory of Open Access Journals (Sweden)

Chinthaka P. Gooneratne

2017-10-01

Full Text Available In this paper we present a review of the application of two types of magnetic sensors—fluxgate magnetometers and nuclear magnetic resonance (NMR sensors—in the oil/gas industry. These magnetic sensors play a critical role in drilling wells safely, accurately and efficiently into a target reservoir zone by providing directional data of the well and acquiring information about the surrounding geological formations. Research into magnetic sensors for oil/gas drilling has not been explored by researchers to the same extent as other applications, such as biomedical, magnetic storage and automotive/aerospace applications. Therefore, this paper aims to serve as an opportunity for researchers to truly understand how magnetic sensors can be used in a downhole environment and to provide fertile ground for research and development in this area. A look ahead, discussing other magnetic sensor technologies that can potentially be used in the oil/gas industry is presented, and what is still needed in order deploy them in the field is also addressed.

System for recording and displaying two-phase flow topographies

International Nuclear Information System (INIS)

Cary, C.N.; Block, J.A.

1979-01-01

A system of hardware and software has been developed and used to record and display in various forms details of the countercurrent flow topographies occurring in a scaled Pressurized Water Reactor downcomer annulus. An array of 288 conductivity sensors was mounted in a 1/15 scale PWR annulus. At each moment in time, the state of each probe indicates the presence or absence of water in this immediate vicinity. An electronic data acquisition system records the states of all probes 108 times per second on magnetic tape; software routines retrieve the data and reconstruct visual analogs of the flow topographies. The instantaneous two-phase state of the annulus at each instant can be displayed on a hard copy plotter or on a CRT screen. By synchronizing a camera drive with the CRT display, 16mm films have been made recreating the flow process at full speed and at various slow motion rates. All data obtained are stored in computer files in numerical form and can be subjected to various types of quantitative analysis to assist in advanced code development and verification

Lighting Control System for Premises with Display Screen Equipment

Science.gov (United States)

Kudryashov, A. V.

2017-11-01

The use of Display Screen Equipment (DSE) at enterprises allows one to increase the productivity and safety of production, minimize the number of personnel and leads to the simplification of the work of specialists, but on the other side, changes usual working conditions. If the personnel works with displays, visual fatigue develops more quickly which contributes to the emergence of nervous tension, stress and possible erroneous actions. Low interest of the lighting control system developers towards the rooms with displays is dictated by special requirements for coverage by sanitary and hygienic standards (limiting excess workplace illumination). We decided to create a combined lighting system which works considering daylight illumination and artificial light sources. The brightness adjustment of the LED lamps is carried out according to the DALI protocol, adjustment of the natural illumination by means of smart glasses. The technical requirements for a lighting control system, the structural-functional scheme and the algorithm for controlling the operation of the system have been developed. The elements of control units, sensors and actuators have been selected.

Infrasound from ground to space

Science.gov (United States)

Bowman, Daniel Charles

Acoustic detector networks are usually located on the Earth's surface. However, these networks suffer from shortcomings such as poor detection range and pervasive wind noise. An alternative is to deploy acoustic sensors on high altitude balloons. In theory, such platforms can resolve signals arriving from great distances, acquire others that never reach the surface at all, and avoid wind noise entirely. This dissertation focuses on scientific advances, instrumentation, and analytical techniques resulting from the development of such sensor arrays. Results from infrasound microphones deployed on balloon flights in the middle stratosphere are described, and acoustic sources such as the ocean microbarom and building ventilation systems are discussed. Electromagnetic noise originating from the balloon, flight system, and other payloads is shown to be a pervasive issue. An experiment investigating acoustic sensor calibration at low pressures is presented, and implications for high altitude recording are considered. Outstanding challenges and opportunities in sound measurement using sensors embedded in the free atmosphere are outlined. Acoustic signals from field scale explosions designed to emulate volcanic eruptions are described, and their generation mechanisms modeled. Wave forms recorded on sensors suspended from tethered helium balloons are compared with those detected on ground stations during the experiment. Finally, the Hilbert-Huang transform, a high time resolution spectral analysis method for nonstationary and nonlinear time series, is presented.

Quality status display for a vibration welding process

Science.gov (United States)

Spicer, John Patrick; Abell, Jeffrey A.; Wincek, Michael Anthony; Chakraborty, Debejyo; Bracey, Jennifer; Wang, Hui; Tavora, Peter W.; Davis, Jeffrey S.; Hutchinson, Daniel C.; Reardon, Ronald L.; Utz, Shawn

2017-11-28

A method includes receiving, during a vibration welding process, a set of sensory signals from a collection of sensors positioned with respect to a work piece during formation of a weld on or within the work piece. The method also includes receiving control signals from a welding controller during the process, with the control signals causing the welding horn to vibrate at a calibrated frequency, and processing the received sensory and control signals using a host machine. Additionally, the method includes displaying a predicted weld quality status on a surface of the work piece using a status projector. The method may include identifying and display a quality status of a suspect weld. The laser projector may project a laser beam directly onto or immediately adjacent to the suspect welds, e.g., as a red, green, blue laser or a gas laser having a switched color filter.

Ground Source Heat Pump in Heating System with Electronics Monitoring

Directory of Open Access Journals (Sweden)

NEAMŢU Ovidiu

2013-10-01

Full Text Available The monitoring system is implemented for a ground coupled heat pump in heating/ system. The borehole heat exchangers – which are 150 m long - are filled with a mixture of water and ethilene glycol calledbrine. Metering and monitoring energy consumption is achieved for: heat pump, circulation pumps, additional electrical heating, hot air ventilation systems, control systems with sensors: analog and smart sensors. Instantaneous values are stored in a local computer.

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

Enhanced chemical weapon warning via sensor fusion

Science.gov (United States)

Flaherty, Michael; Pritchett, Daniel; Cothren, Brian; Schwaiger, James

2011-05-01

Torch Technologies Inc., is actively involved in chemical sensor networking and data fusion via multi-year efforts with Dugway Proving Ground (DPG) and the Defense Threat Reduction Agency (DTRA). The objective of these efforts is to develop innovative concepts and advanced algorithms that enhance our national Chemical Warfare (CW) test and warning capabilities via the fusion of traditional and non-traditional CW sensor data. Under Phase I, II, and III Small Business Innovative Research (SBIR) contracts with DPG, Torch developed the Advanced Chemical Release Evaluation System (ACRES) software to support non real-time CW sensor data fusion. Under Phase I and II SBIRs with DTRA in conjunction with the Edgewood Chemical Biological Center (ECBC), Torch is using the DPG ACRES CW sensor data fuser as a framework from which to develop the Cloud state Estimation in a Networked Sensor Environment (CENSE) data fusion system. Torch is currently developing CENSE to implement and test innovative real-time sensor network based data fusion concepts using CW and non-CW ancillary sensor data to improve CW warning and detection in tactical scenarios.

Recce NG: from Recce sensor to image intelligence (IMINT)

Science.gov (United States)

Larroque, Serge

2001-12-01

Recce NG (Reconnaissance New Generation) is presented as a complete and optimized Tactical Reconnaissance System. Based on a new generation Pod integrating high resolution Dual Band sensors, the system has been designed with the operational lessons learnt from the last Peace Keeping Operations in Bosnia and Kosovo. The technical solutions retained as component modules of a full IMINT acquisition system, take benefit of the state of art in the following key technologies: Advanced Mission Planning System for long range stand-off Manned Recce, Aircraft and/or Pod tasking, operating sophisticated back-up software tools, high resolution 3D geo data and improved/combat proven MMI to reduce planning delays, Mature Dual Band sensors technology to achieve the Day and Night Recce Mission, including advanced automatic operational functions, as azimuth and roll tracking capabilities, low risk in Pod integration and in carrier avionics, controls and displays upgrades, to save time in operational turn over and maintenance, High rate Imagery Down Link, for Real Time or Near Real Time transmission, fully compatible with STANAG 7085 requirements, Advanced IMINT Exploitation Ground Segment, combat proven, NATO interoperable (STANAG 7023), integrating high value software tools for accurate location, improved radiometric image processing and open link to the C4ISR systems. The choice of an industrial Prime contractor mastering across the full system, all the prior listed key products and technologies, is mandatory to a successful delivery in terms of low Cost, Risk and Time Schedule.

Design and Evaluation of a Wireless Sensor Network Based Aircraft Strength Testing System

Science.gov (United States)

Wu, Jian; Yuan, Shenfang; Zhou, Genyuan; Ji, Sai; Wang, Zilong; Wang, Yang

2009-01-01

The verification of aerospace structures, including full-scale fatigue and static test programs, is essential for structure strength design and evaluation. However, the current overall ground strength testing systems employ a large number of wires for communication among sensors and data acquisition facilities. The centralized data processing makes test programs lack efficiency and intelligence. Wireless sensor network (WSN) technology might be expected to address the limitations of cable-based aeronautical ground testing systems. This paper presents a wireless sensor network based aircraft strength testing (AST) system design and its evaluation on a real aircraft specimen. In this paper, a miniature, high-precision, and shock-proof wireless sensor node is designed for multi-channel strain gauge signal conditioning and monitoring. A cluster-star network topology protocol and application layer interface are designed in detail. To verify the functionality of the designed wireless sensor network for strength testing capability, a multi-point WSN based AST system is developed for static testing of a real aircraft undercarriage. Based on the designed wireless sensor nodes, the wireless sensor network is deployed to gather, process, and transmit strain gauge signals and monitor results under different static test loads. This paper shows the efficiency of the wireless sensor network based AST system, compared to a conventional AST system. PMID:22408521

Design and evaluation of a wireless sensor network based aircraft strength testing system.

Science.gov (United States)

Wu, Jian; Yuan, Shenfang; Zhou, Genyuan; Ji, Sai; Wang, Zilong; Wang, Yang

2009-01-01

The verification of aerospace structures, including full-scale fatigue and static test programs, is essential for structure strength design and evaluation. However, the current overall ground strength testing systems employ a large number of wires for communication among sensors and data acquisition facilities. The centralized data processing makes test programs lack efficiency and intelligence. Wireless sensor network (WSN) technology might be expected to address the limitations of cable-based aeronautical ground testing systems. This paper presents a wireless sensor network based aircraft strength testing (AST) system design and its evaluation on a real aircraft specimen. In this paper, a miniature, high-precision, and shock-proof wireless sensor node is designed for multi-channel strain gauge signal conditioning and monitoring. A cluster-star network topology protocol and application layer interface are designed in detail. To verify the functionality of the designed wireless sensor network for strength testing capability, a multi-point WSN based AST system is developed for static testing of a real aircraft undercarriage. Based on the designed wireless sensor nodes, the wireless sensor network is deployed to gather, process, and transmit strain gauge signals and monitor results under different static test loads. This paper shows the efficiency of the wireless sensor network based AST system, compared to a conventional AST system.

Customer Avionics Interface Development and Analysis (CAIDA) Lab DEWESoft Display Creation

Science.gov (United States)

Coffey, Connor

2015-01-01

The Customer Avionics Interface Development and Analysis (CAIDA) Lab supports the testing of the Launch Control System (LCS), NASA's command and control system for the Space Launch System (SLS), Orion Multi-Purpose Crew Vehicle (MPCV), and ground support equipment. The objectives of the year-long internship were to support day-to-day operations of the CAIDA Lab, create prelaunch and tracking displays for Orion's Exploration Flight Test 1 (EFT-1), and create a program to automate the creation of displays for SLS and MPCV to be used by CAIDA and the Record and Playback Subsystem (RPS).

Ground Control System Description Document

International Nuclear Information System (INIS)

Eric Loros

2001-01-01

The Ground Control System contributes to the safe construction and operation of the subsurface facility, including accesses and waste emplacement drifts, by maintaining the configuration and stability of the openings during construction, development, emplacement, and caretaker modes for the duration of preclosure repository life. The Ground Control System consists of ground support structures installed within the subsurface excavated openings, any reinforcement made to the rock surrounding the opening, and inverts if designed as an integral part of the system. The Ground Control System maintains stability for the range of geologic conditions expected at the repository and for all expected loading conditions, including in situ rock, construction, operation, thermal, and seismic loads. The system maintains the size and geometry of operating envelopes for all openings, including alcoves, accesses, and emplacement drifts. The system provides for the installation and operation of sensors and equipment for any required inspection and monitoring. In addition, the Ground Control System provides protection against rockfall for all subsurface personnel, equipment, and the engineered barrier system, including the waste package during the preclosure period. The Ground Control System uses materials that are sufficiently maintainable and that retain the necessary engineering properties for the anticipated conditions of the preclosure service life. These materials are also compatible with postclosure waste isolation performance requirements of the repository. The Ground Control System interfaces with the Subsurface Facility System for operating envelopes, drift orientation, and excavated opening dimensions, Emplacement Drift System for material compatibility, Monitored Geologic Repository Operations Monitoring and Control System for ground control instrument readings, Waste Emplacement/Retrieval System to support waste emplacement operations, and the Subsurface Excavation System

RuO2 pH Sensor with Super-Glue-Inspired Reference Electrode

OpenAIRE

Lonsdale, Wade; Wajrak, Magdalena; Alameh, Kamal

2017-01-01

A pH-sensitive RuO2 electrode coated in a commercial cyanoacrylate adhesive typically exhibits very low pH sensitivity, and could be paired with a RuO2 working electrode as a differential type pH sensor. However, such sensors display poor performance in real sample matrices. A pH sensor employing a RuO2 pH-sensitive working electrode and a SiO2-PVB junction-modified RuO2 reference electrode is developed as an alternative high-performance solution. This sensor exhibits a performance similar to...

System-in Package of Integrated Humidity Sensor Using CMOS-MEMS Technology.

Science.gov (United States)

Lee, Sung Pil

2015-10-01

Temperature/humidity microchips with micropump were fabricated using a CMOS-MEMS process and combined with ZigBee modules to implement a sensor system in package (SIP) for a ubiquitous sensor network (USN) and/or a wireless communication system. The current of a diode temperature sensor to temperature and a normalized current of FET humidity sensor to relative humidity showed linear characteristics, respectively, and the use of the micropump has enabled a faster response. A wireless reception module using the same protocol as that in transmission systems processed the received data within 10 m and showed temperature and humidity values in the display.

A comparison of decision-level sensor-fusion methods for anti-personnel landmine detection.

NARCIS (Netherlands)

Schutte, K.; Schavemaker, J.G.M.; Cremer, F.; Breejen, E. den

2001-01-01

We present the sensor-fusion results obtained from measurements within the European research project ground explosive ordinance detection (GEODE) system that strives for the realisation of a vehicle-mounted, multi-sensor, anti-personnel landmine-detection system for humanitarian de-mining. The

Calibrated infrared ground/air radiometric spectrometer

Science.gov (United States)

Silk, J. K.; Schildkraut, Elliot Robert; Bauldree, Russell S.; Goodrich, Shawn M.

1996-06-01

The calibrated infrared ground/air radiometric spectrometer (CIGARS) is a new high performance, multi-purpose, multi- platform Fourier transform spectrometer (FPS) sensor. It covers the waveband from 0.2 to 12 micrometer, has spectral resolution as fine as 0.3 cm-1, and records over 100 spectra per second. Two CIGARS units are being used for observations of target signatures in the air or on the ground from fixed or moving platforms, including high performance jet aircraft. In this paper we describe the characteristics and capabilities of the CIGARS sensor, which uses four interchangeable detector modules (Si, InGaAs, InSb, and HgCdTe) and two optics modules, with internal calibration. The data recording electronics support observations of transient events, even without precise information on the timing of the event. We present test and calibration data on the sensitivity, spectral resolution, stability, and spectral rate of CIGARS, and examples of in- flight observations of real targets. We also discuss plans for adapting CIGARS for imaging spectroscopy observations, with simultaneous spectral and spatial data, by replacing the existing detectors with a focal plane array (FPA).

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.

Wearable sensor glove based on conducting fabric using electrodermal activity and pulse-wave sensors for e-health application.

Science.gov (United States)

Lee, Youngbum; Lee, Byungwoo; Lee, Myoungho

2010-03-01

Improvement of the quality and efficiency of health in medicine, both at home and the hospital, calls for improved sensors that might be included in a common carrier such as a wearable sensor device to measure various biosignals and provide healthcare services that use e-health technology. Designed to be user-friendly, smart clothes and gloves respond well to the end users for health monitoring. This study describes a wearable sensor glove that is equipped with an electrodermal activity (EDA) sensor, pulse-wave sensor, conducting fabric, and an embedded system. The EDA sensor utilizes the relationship between drowsiness and the EDA signal. The EDA sensors were made using a conducting fabric instead of silver chloride electrodes, as a more practical and practically wearable device. The pulse-wave sensor measurement system, which is widely applied in oriental medicinal practices, is also a strong element in e-health monitoring systems. The EDA and pulse-wave signal acquisition module was constructed by connecting the sensor to the glove via a conductive fabric. The signal acquisition module is then connected to a personal computer that displays the results of the EDA and pulse-wave signal processing analysis and gives accurate feedback to the user. This system is designed for a number of applications for the e-health services, including drowsiness detection and oriental medicine.

A pilot project combining multispectral proximal sensors and digital cameras for monitoring tropical pastures

Science.gov (United States)

Handcock, Rebecca N.; Gobbett, D. L.; González, Luciano A.; Bishop-Hurley, Greg J.; McGavin, Sharon L.

2016-08-01

Timely and accurate monitoring of pasture biomass and ground cover is necessary in livestock production systems to ensure productive and sustainable management. Interest in the use of proximal sensors for monitoring pasture status in grazing systems has increased, since data can be returned in near real time. Proximal sensors have the potential for deployment on large properties where remote sensing may not be suitable due to issues such as spatial scale or cloud cover. There are unresolved challenges in gathering reliable sensor data and in calibrating raw sensor data to values such as pasture biomass or vegetation ground cover, which allow meaningful interpretation of sensor data by livestock producers. Our goal was to assess whether a combination of proximal sensors could be reliably deployed to monitor tropical pasture status in an operational beef production system, as a precursor to designing a full sensor deployment. We use this pilot project to (1) illustrate practical issues around sensor deployment, (2) develop the methods necessary for the quality control of the sensor data, and (3) assess the strength of the relationships between vegetation indices derived from the proximal sensors and field observations across the wet and dry seasons. Proximal sensors were deployed at two sites in a tropical pasture on a beef production property near Townsville, Australia. Each site was monitored by a Skye SKR-four-band multispectral sensor (every 1 min), a digital camera (every 30 min), and a soil moisture sensor (every 1 min), each of which were operated over 18 months. Raw data from each sensor was processed to calculate multispectral vegetation indices. The data capture from the digital cameras was more reliable than the multispectral sensors, which had up to 67 % of data discarded after data cleaning and quality control for technical issues related to the sensor design, as well as environmental issues such as water incursion and insect infestations. We recommend

Real-time display of flow-pressure-volume loops.

Science.gov (United States)

Morozoff, P E; Evans, R W

1992-01-01

Graphic display of respiratory waveforms can be valuable for monitoring the progress of ventilated patients. A system has been developed that can display flow-pressure-volume loops as derived from a patient's respiratory circuit in real time. It can also display, store, print, and retrieve ventilatory waveforms. Five loops can be displayed at once: current, previous, reference, "ideal," and previously saved. Two components, the data-display device (DDD) and the data-collection device (DCD), comprise the system. An IBM 286/386 computer with a graphics card (VGA) and bidirectional parallel port is used for the DDD; an eight-bit microprocessor card and an A/D convertor card make up the DCD. A real-time multitasking operating system was written to control the DDD, while the DCD operates from in-line assembly code. The DCD samples the pressure and flow sensors at 100 Hz and looks for a complete flow waveform pattern based on flow slope. These waveforms are then passed to the DDD via the mutual parallel port. Within the DDD a process integrates the flow to create a volume signal and performs a multilinear regression on the pressure, flow, and volume data to calculate the elastance, resistance, pressure offset, and coefficient of determination. Elastance, resistance, and offset are used to calculate Pr and Pc where: Pr[k] = P[k]-offset-(elastance.V[k]) and Pc[k] = P[k]-offset-(resistance.F[k]). Volume vs. Pc and flow vs. Pr can be displayed in real time. Patient data from previous clinical tests were loaded into the device to verify the software calculations. An analog waveform generator was used to simulate flow and pressure waveforms that validated the system.(ABSTRACT TRUNCATED AT 250 WORDS)

Design of power cable grounding wire anti-theft monitoring system

Science.gov (United States)

An, Xisheng; Lu, Peng; Wei, Niansheng; Hong, Gang

2018-01-01

In order to prevent the serious consequences of the power grid failure caused by the power cable grounding wire theft, this paper presents a GPRS based power cable grounding wire anti-theft monitoring device system, which includes a camera module, a sensor module, a micro processing system module, and a data monitoring center module, a mobile terminal module. Our design utilize two kinds of methods for detecting and reporting comprehensive image, it can effectively solve the problem of power and cable grounding wire box theft problem, timely follow-up grounded cable theft events, prevent the occurrence of electric field of high voltage transmission line fault, improve the reliability of the safe operation of power grid.

The ground support computer and in-orbit survey data analysis program for the SEEP experiment

International Nuclear Information System (INIS)

Voss, H.D.; Datlowe, D.W.; Mobilia, J.; Roselle, S.N.

1985-01-01

The ground support computer equipment (GSE) and production survey plot and analysis software are described for the Stimulated Emissions of Energetic Particles (SEEP) experiment on the S81-1 satellite. A general purpose satellite data acquisition circuit was developed based on a Z-80 portable microcomputer. By simply changing instrument control software and electrical connectors, automatic testing and control of the various SEEP instruments was accomplished. A new feature incorporated into the SEEP data analysis phase was the development of a correlative data base for all of the SEEP instruments. A CPU efficient survey plot program (with ephemeris) was developed to display the approximate 3100 hours of data, with a time resolution of 0.5 sec, from the ten instrument sensors. The details of the general purpose multigraph algorithms and plot formats are presented. For the first time new associations are being investigated of simultaneous particle, X-ray, optical and plasma density satellite measurements

Preliminary data for the 20 May 1974, simultaneous evaluation of remote sensors experiment. [water pollution monitoring

Science.gov (United States)

Johnson, R. W.; Batten, C. E.; Bowker, D. E.; Bressette, W. E.; Grew, G. W.

1975-01-01

Several remote sensors were simultaneously used to collect data over the tidal James River from Hopewell to Norfolk, Virginia. Sensors evaluated included the Multichannel-Ocean Color Sensor, multispectral scanners, and multispectral photography. Ground truth measurements and remotely sensed data are given. Preliminary analysis indicates that suspended sediment and concentrated industrial effluent are observable from all sensors.

Absolute Position Sensing Based on a Robust Differential Capacitive Sensor with a Grounded Shield Window

Directory of Open Access Journals (Sweden)

Yang Bai

2016-05-01

Full Text Available A simple differential capacitive sensor is provided in this paper to measure the absolute positions of length measuring systems. By utilizing a shield window inside the differential capacitor, the measurement range and linearity range of the sensor can reach several millimeters. What is more interesting is that this differential capacitive sensor is only sensitive to one translational degree of freedom (DOF movement, and immune to the vibration along the other two translational DOFs. In the experiment, we used a novel circuit based on an AC capacitance bridge to directly measure the differential capacitance value. The experimental result shows that this differential capacitive sensor has a sensitivity of 2 × 10−4 pF/μm with 0.08 μm resolution. The measurement range of this differential capacitive sensor is 6 mm, and the linearity error are less than 0.01% over the whole absolute position measurement range.

FlyTact : A tactile display improves a helicopter pilot's landing performance in degraded visual environments

NARCIS (Netherlands)

Jansen, C.; Wennemers, A.S.; Vos, W.K.; Groen, E.L.

2008-01-01

Helicopter landings are more challenging in 'brownout' conditions, in which sand and dust is stirred up by the rotary wing aircraft, obscuring visibility. Safe brownout landings require new sensor and display technologies to provide the pilot with information on helicopter motion. In this respect

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.

Sensors and sensor systems for guidance and navigation II; Proceedings of the Meeting, Orlando, FL, Apr. 22, 23, 1992

Science.gov (United States)

Welch, Sharon S.

Topics discussed in this volume include aircraft guidance and navigation, optics for visual guidance of aircraft, spacecraft and missile guidance and navigation, lidar and ladar systems, microdevices, gyroscopes, cockpit displays, and automotive displays. Papers are presented on optical processing for range and attitude determination, aircraft collision avoidance using a statistical decision theory, a scanning laser aircraft surveillance system for carrier flight operations, star sensor simulation for astroinertial guidance and navigation, autonomous millimeter-wave radar guidance systems, and a 1.32-micron long-range solid state imaging ladar. Attention is also given to a microfabricated magnetometer using Young's modulus changes in magnetoelastic materials, an integrated microgyroscope, a pulsed diode ring laser gyroscope, self-scanned polysilicon active-matrix liquid-crystal displays, the history and development of coated contrast enhancement filters for cockpit displays, and the effect of the display configuration on the attentional sampling performance. (For individual items see A93-28152 to A93-28176, A93-28178 to A93-28180)

Tracking heat flux sensors for concentrating solar applications

Science.gov (United States)

Andraka, Charles E; Diver, Jr., Richard B

2013-06-11

Innovative tracking heat flux sensors located at or near the solar collector's focus for centering the concentrated image on a receiver assembly. With flux sensors mounted near a receiver's aperture, the flux gradient near the focus of a dish or trough collector can be used to precisely position the focused solar flux on the receiver. The heat flux sensors comprise two closely-coupled thermocouple junctions with opposing electrical polarity that are separated by a thermal resistor. This arrangement creates an electrical signal proportional to heat flux intensity, and largely independent of temperature. The sensors are thermally grounded to allow a temperature difference to develop across the thermal resistor, and are cooled by a heat sink to maintain an acceptable operating temperature.

Doppler lidar sensor for precision navigation in GPS-deprived environment

Science.gov (United States)

Amzajerdian, F.; Pierrottet, D. F.; Hines, G. D.; Petway, L. B.; Barnes, B. W.

2013-05-01

Landing mission concepts that are being developed for exploration of solar system bodies are increasingly ambitious in their implementations and objectives. Most of these missions require accurate position and velocity data during their descent phase in order to ensure safe, soft landing at the pre-designated sites. Data from the vehicle's Inertial Measurement Unit will not be sufficient due to significant drift error after extended travel time in space. Therefore, an onboard sensor is required to provide the necessary data for landing in the GPS-deprived environment of space. For this reason, NASA Langley Research Center has been developing an advanced Doppler lidar sensor capable of providing accurate and reliable data suitable for operation in the highly constrained environment of space. The Doppler lidar transmits three laser beams in different directions toward the ground. The signal from each beam provides the platform velocity and range to the ground along the laser line-of-sight (LOS). The six LOS measurements are then combined in order to determine the three components of the vehicle velocity vector, and to accurately measure altitude and attitude angles relative to the local ground. These measurements are used by an autonomous Guidance, Navigation, and Control system to accurately navigate the vehicle from a few kilometers above the ground to the designated location and to execute a gentle touchdown. A prototype version of our lidar sensor has been completed for a closed-loop demonstration onboard a rocket-powered terrestrial free-flyer vehicle.

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.

Circular displays: control/display arrangements and stereotype strength with eight different display locations.

Science.gov (United States)

Chan, Alan H S; Hoffmann, Errol R

2015-01-01

Two experiments are reported that were designed to investigate control/display arrangements having high stereotype strengths when using circular displays. Eight display locations relative to the operator and control were tested with rotational and translational controls situated on different planes according to the Frame of Reference Transformation Tool (FORT) model of Wickens et al. (2010). (Left. No, Right! Development of the Frame of Reference Transformation Tool (FORT), Proceedings of the Human Factors and Ergonomics Society 54th Annual Meeting, 54: 1022-1026). In many cases, there was little effect of display locations, indicating the importance of the Worringham and Beringer (1998. Directional stimulus-response compatibility: a test of three alternative principles. Ergonomics, 41(6), 864-880) Visual Field principle and an extension of this principle for rotary controls (Hoffmann and Chan (2013). The Worringham and Beringer 'visual field' principle for rotary controls. Ergonomics, 56(10), 1620-1624). The initial indicator position (12, 3, 6 and 9 o'clock) had a major effect on control/display stereotype strength for many of the six controls tested. Best display/control arrangements are listed for each of the different control types (rotational and translational) and for the planes on which they are mounted. Data have application where a circular display is used due to limited display panel space and applies to space-craft, robotics operators, hospital equipment and home appliances. Practitioner Summary: Circular displays are often used when there is limited space available on a control panel. Display/control arrangements having high stereotype strength are listed for four initial indicator positions. These arrangements are best for design purposes.

17th National Conference on Sensors and Microsystems

CERN Document Server

Ferrari, Vittorio; Ponzoni, Andrea; Sberveglieri, Giorgio; Ferrari, Marco

2014-01-01

This book contains a selection of papers presented at the 17th AISEM (“Associazione Italiana Sensori e Microsistemi”) National Conference on Sensors and Microsystems, held in Brescia, 5-7 February, 2013. The conference highlighted state-of-the-art results from both theoretical and applied research in the field of sensors and related technologies. This book presents material in an interdisciplinary approach, covering many aspects of the disciplines related to sensors, including physics, chemistry, materials science, biology and applications.  ·         Provides a selection of the best papers from the 17th National Conference on Sensors and Microsystems; ·         Covers a broad range of topics relating to sensors and microsystems, including physics, chemistry, materials science, biology and applications; ·         Offers interdisciplinary coverage, aimed at defining a common ground for sensors beyond the specific differences among the different particular implementation of senso...

Evaluation of a HDR image sensor with logarithmic response for mobile video-based applications

Science.gov (United States)

Tektonidis, Marco; Pietrzak, Mateusz; Monnin, David

2017-10-01

The performance of mobile video-based applications using conventional LDR (Low Dynamic Range) image sensors highly depends on the illumination conditions. As an alternative, HDR (High Dynamic Range) image sensors with logarithmic response are capable to acquire illumination-invariant HDR images in a single shot. We have implemented a complete image processing framework for a HDR sensor, including preprocessing methods (nonuniformity correction (NUC), cross-talk correction (CTC), and demosaicing) as well as tone mapping (TM). We have evaluated the HDR sensor for video-based applications w.r.t. the display of images and w.r.t. image analysis techniques. Regarding the display we have investigated the image intensity statistics over time, and regarding image analysis we assessed the number of feature correspondences between consecutive frames of temporal image sequences. For the evaluation we used HDR image data recorded from a vehicle on outdoor or combined outdoor/indoor itineraries, and we performed a comparison with corresponding conventional LDR image data.

Block ground interaction of rockfalls

Science.gov (United States)

Volkwein, Axel; Gerber, Werner; Kummer, Peter

2016-04-01

During a rockfall the interaction of the falling block with the ground is one of the most important factors that define the evolution of a rockfall trajectory. It steers the rebound, the rotational movement, possibly brake effects, friction losses and damping effects. Therefore, if most reliable rockfall /trajectory simulation software is sought a good understanding of the block ground interaction is necessary. Today's rockfall codes enable the simulation of a fully 3D modelled block within a full 3D surface . However, the details during the contact, i.e. the contact duration, the penetration depth or the dimension of the marks in the ground are usually not part of the simulation. Recent field tests with rocks between 20 and 80 kg have been conducted on a grassy slope in 2014 [1]. A special rockfall sensor [2] within the blocks measured the rotational velocity and the acting accelerations during the tests. External video records and a so-called LocalPositioningSystem deliver information on the travel velocity. With these data not only the flight phases of the trajectories but also the contacts with the ground can be analysed. During the single jumps of a block the flight time, jump length, the velocity, and the rotation are known. During the single impacts their duration and the acting accelerations are visible. Further, the changes of rotational and translational velocity influence the next jump of the block. The change of the rotational velocity over the whole trajectory nicely visualizes the different phases of a rockfall regarding general acceleration and deceleration in respect to the inclination and the topography of the field. References: [1] Volkwein A, Krummenacher B, Gerber W, Lardon J, Gees F, Brügger L, Ott T (2015) Repeated controlled rockfall trajectory testing. [Abstract] Geophys. Res. Abstr. 17: EGU2015-9779. [2] Volkwein A, Klette J (2014) Semi-Automatic Determination of Rockfall Trajectories. Sensors 14: 18187-18210.

Utilization of biosensors and chemical sensors for space applications

Science.gov (United States)

Bonting, S. L.

1992-01-01

There will be a need for a wide array of chemical sensors for biomedical experimentation and for the monitoring of water and air recycling processes on Space Station Freedom. The infrequent logistics flights of the Space Shuttle will necessitate onboard analysis. The advantages of biosensors and chemical sensors over conventional analysis onboard spacecraft are manifold. They require less crew time, space, and power. Sample treatment is not needed. Real time or near-real time monitoring is possible, in some cases on a continuous basis. Sensor signals in digitized form can be transmitted to the ground. Types and requirements for chemical sensors to be used in biomedical experimentation and monitoring of water recycling during long-term space missions are discussed.

Performance of an Advanced Stirling Convertor Based on Heat Flux Sensor Measurements

Science.gov (United States)

Wilson, Dcott D.

2012-01-01

The U.S. Department of Energy (DOE) and Lockheed Martin Space Systems Company (LMSSC) have been developing the Advanced Stirling Radioisotope Generator (ASRG) for use as a power system for space science missions. This generator would use two highefficiency Advanced Stirling Convertors (ASCs), developed by Sunpower, Inc., and NASA Glenn Research Center. The ASCs convert thermal energy from a radioisotope heat source into electricity. As part of ground testing of these ASCs, different operating conditions are used to simulate expected mission conditions. These conditions require achieving a particular operating frequency, hot-end and cold-end temperatures, and specified electrical power output for a given heat input. It is difficult to measure heat input to Stirling convertors due to the complex geometries of the hot components, temperature limits of sensor materials, and invasive integration of sensors. A thin-film heat flux sensor was used to directly measure heat input to an ASC. The effort succeeded in designing and fabricating unique sensors, which were integrated into a Stirling convertor ground test and exposed to test temperatures exceeding 700 C in air for 10,000 hr. Sensor measurements were used to calculate thermal efficiency for ASC-E (Engineering Unit) #1 and #4. The post-disassembly condition of the sensors is also discussed.

Catalog of physical protection equipment. Book 3: Volume VII. General purpose display components

International Nuclear Information System (INIS)

1977-06-01

A catalog of commercially available physical protection equipment has been prepared under MITRE contract AT(49-24)-0376 for use by the U. S. Nuclear Regulatory Commission (NRC). Included is information on barrier structures and equipment, interior and exterior intrusion detection sensors, entry (access) control devices, surveillance and alarm assessment equipment, contraband detection sensors, automated response equipment, general purpose displays and general purpose communications, with one volume devoted to each of these eight areas. For each item of equipment the information included consists of performance, physical, cost and supply/logistics data. The entire catalog is contained in three notebooks for ease in its use by licensing and inspection staff at NRC

Nighttime Aerosol Optical Depth Measurements Using a Ground-based Lunar Photometer

Science.gov (United States)

Berkoff, Tim; Omar, Ali; Haggard, Charles; Pippin, Margaret; Tasaddaq, Aasam; Stone, Tom; Rodriguez, Jon; Slutsker, Ilya; Eck, Tom; Holben, Brent;

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.

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.

Multipoint sensor based on fiber Bragg gratings

International Nuclear Information System (INIS)

Mendez-Zepeda, O; Munoz-Aguirre, S; Beltran-Perez, G; Castillo-Mixcoatl, J

2011-01-01

In some control and industrial measurement systems of physical variables (pressure, temperature, flow, etc) it is necessary one system and one sensor to control each process. On the other hand, there are systems such as PLC (Programmable Logic Control), which can process several signals simultaneously. However it is still necessary to use one sensor for each variable. Therefore, in the present work the use of a multipoint sensor to solve such problem has been proposed. The sensor consists of an optical fiber laser with two Fabry-Perot cavities constructed using fiber Bragg gratings (FBG). In the same system is possible to measure changes in two variables by detecting the intermodal separation frequency of each cavity and evaluate their amplitudes. The intermodal separation frequency depends on each cavity length. The sensor signals are monitored through an oscilloscope or a PCI card and after that acquired by PC, where they are analyzed and displayed. Results of the evaluation of the intermodal frequency separation peak amplitude behavior with FBG stretching are presented.

800 C Silicon Carbide (SiC) Pressure Sensors for Engine Ground Testing

Science.gov (United States)

Okojie, Robert S.

2016-01-01

MEMS-based 4H-SiC piezoresistive pressure sensors have been demonstrated at 800 C, leading to the discovery of strain sensitivity recovery with increasing temperatures above 400 C, eventually achieving up to, or near, 100 recovery of the room temperature values at 800 C. This result will allow the insertion of highly sensitive pressure sensors closer to jet, rocket, and hypersonic engine combustion chambers to improve the quantification accuracy of combustor dynamics, performance, and increase safety margin. Also, by operating at higher temperature and locating closer to the combustion chamber, reduction of the length (weight) of pressure tubes that are currently used will be achieved. This will result in reduced costlb to access space.

Multi-sensor image fusion and its applications

CERN Document Server

Blum, Rick S

2005-01-01

Taking another lesson from nature, the latest advances in image processing technology seek to combine image data from several diverse types of sensors in order to obtain a more accurate view of the scene: very much the same as we rely on our five senses. Multi-Sensor Image Fusion and Its Applications is the first text dedicated to the theory and practice of the registration and fusion of image data, covering such approaches as statistical methods, color-related techniques, model-based methods, and visual information display strategies.After a review of state-of-the-art image fusion techniques,

Remotely Piloted Aircraft Systems and a Wireless Sensors Network for Radiological Accidents

Directory of Open Access Journals (Sweden)

A. Reyes-Muñoz

2016-01-01

Full Text Available In critical radiological situations, the real time information that we could get from the disaster area becomes of great importance. However, communication systems could be affected after a radiological accident. The proposed network in this research consists of distributed sensors in charge of collecting radiological data and ground vehicles that are sent to the nuclear plant at the moment of the accident to sense environmental and radiological information. Afterwards, data would be analyzed in the control center. Collected data by sensors and ground vehicles would be delivered to a control center using Remotely Piloted Aircraft Systems (RPAS as a message carrier. We analyze the pairwise contacts, as well as visiting times, data collection, capacity of the links, size of the transmission window of the sensors, and so forth. All this calculus was made analytically and compared via network simulations.

Design of multi-function sensor detection system in coal mine based on ARM

Science.gov (United States)

Ge, Yan-Xiang; Zhang, Quan-Zhu; Deng, Yong-Hong

2017-06-01

The traditional coal mine sensor in the specific measurement points, the number and type of channel will be greater than or less than the number of monitoring points, resulting in a waste of resources or cannot meet the application requirements, in order to enable the sensor to adapt to the needs of different occasions and reduce the cost, a kind of multi-functional intelligent sensor multiple sensors and ARM11 the S3C6410 processor is used to design and realize the dust, gas, temperature and humidity sensor functions together, and has storage, display, voice, pictures, data query, alarm and other new functions.

The effect of display movement angle, indicator type and display location on control/display stereotype strength.

Science.gov (United States)

Hoffmann, Errol R; Chan, Alan H S

2017-08-01

Much research on stereotype strength relating display and control movements for displays moving in the vertical or horizontal directions has been reported. Here we report effects of display movement angle, where the display moves at angles (relative to the vertical) of between 0° and 180°. The experiment used six different controls, four display locations relative to the operator and three types of indicator. Indicator types were included because of the strong effects of the 'scale-side principle' that are variable with display angle. A directional indicator had higher stereotype strength than a neutral indicator, and showed an apparent reversal in control/display stereotype direction beyond an angle of 90°. However, with a neutral indicator this control reversal was not present. Practitioner Summary: The effects of display moving at angles other than the four cardinal directions, types of control, location of display and types of indicator are investigated. Indicator types (directional and neutral) have an effect on stereotype strength and may cause an apparent control reversal with change of display movement angle.

A Forest Fire Sensor Web Concept with UAVSAR

Science.gov (United States)

Lou, Y.; Chien, S.; Clark, D.; Doubleday, J.; Muellerschoen, R.; Zheng, Y.

2008-12-01

We developed a forest fire sensor web concept with a UAVSAR-based smart sensor and onboard automated response capability that will allow us to monitor fire progression based on coarse initial information provided by an external source. This autonomous disturbance detection and monitoring system combines the unique capabilities of imaging radar with high throughput onboard processing technology and onboard automated response capability based on specific science algorithms. In this forest fire sensor web scenario, a fire is initially located by MODIS/RapidFire or a ground-based fire observer. This information is transmitted to the UAVSAR onboard automated response system (CASPER). CASPER generates a flight plan to cover the alerted fire area and executes the flight plan. The onboard processor generates the fuel load map from raw radar data, used with wind and elevation information, predicts the likely fire progression. CASPER then autonomously alters the flight plan to track the fire progression, providing this information to the fire fighting team on the ground. We can also relay the precise fire location to other remote sensing assets with autonomous response capability such as Earth Observation-1 (EO-1)'s hyper-spectral imager to acquire the fire data.

Microfluidic EBG Sensor Based on Phase-Shift Method Realized Using 3D Printing Technology.

Science.gov (United States)

Radonić, Vasa; Birgermajer, Slobodan; Kitić, Goran

2017-04-18

In this article, we propose a novel microfluidic microstrip electromagnetic band gap (EBG) sensor realized using cost-effective 3D printing technology. Microstrip sensor allows monitoring of the fluid properties flowing in the microchannel embedded between the microstrip line and ground plane. The sensor's operating principle is based on the phase-shift method, which allows the characterization at a single operating frequency of 6 GHz. The defected electromagnetic band gap (EBG) structure is realized as a pattern in the microstrip ground plane to improve sensor sensitivity. The designed microfluidic channel is fabricated using a fused deposition modelling (FDM) 3D printing process without additional supporting layers, while the conductive layers are realized using sticky aluminium tape. The measurement results show that the change of permittivity of the fluid in the microfluidic channel from 1 to 80 results in the phase-shift difference of almost 90°. The potential application is demonstrated through the implementation of a proposed sensor for the detection of toluene concentration in toluene-methanol mixture where various concentrations of toluene were analysed.

Highly sensitive strain sensors based on fragmentized carbon nanotube/polydimethylsiloxane composites.

Science.gov (United States)

Gao, Yang; Fang, Xiaoliang; Tan, Jianping; Lu, Ting; Pan, Likun; Xuan, Fuzhen

2018-06-08

Wearable strain sensors based on nanomaterial/elastomer composites have potential applications in flexible electronic skin, human motion detection, human-machine interfaces, etc. In this research, a type of high performance strain sensors has been developed using fragmentized carbon nanotube/polydimethylsiloxane (CNT/PDMS) composites. The CNT/PDMS composites were ground into fragments, and a liquid-induced densification method was used to fabricate the strain sensors. The strain sensors showed high sensitivity with gauge factors (GFs) larger than 200 and a broad strain detection range up to 80%, much higher than those strain sensors based on unfragmentized CNT/PDMS composites (GF sensors is ascribed to the sliding of individual fragmentized-CNT/PDMS-composite particles during mechanical deformation, which causes significant resistance change in the strain sensors. The strain sensors can differentiate mechanical stimuli and monitor various human body motions, such as bending of the fingers, human breathing, and blood pulsing.

Highly sensitive strain sensors based on fragmentized carbon nanotube/polydimethylsiloxane composites

Science.gov (United States)

Gao, Yang; Fang, Xiaoliang; Tan, Jianping; Lu, Ting; Pan, Likun; Xuan, Fuzhen

2018-06-01

Wearable strain sensors based on nanomaterial/elastomer composites have potential applications in flexible electronic skin, human motion detection, human–machine interfaces, etc. In this research, a type of high performance strain sensors has been developed using fragmentized carbon nanotube/polydimethylsiloxane (CNT/PDMS) composites. The CNT/PDMS composites were ground into fragments, and a liquid-induced densification method was used to fabricate the strain sensors. The strain sensors showed high sensitivity with gauge factors (GFs) larger than 200 and a broad strain detection range up to 80%, much higher than those strain sensors based on unfragmentized CNT/PDMS composites (GF composite particles during mechanical deformation, which causes significant resistance change in the strain sensors. The strain sensors can differentiate mechanical stimuli and monitor various human body motions, such as bending of the fingers, human breathing, and blood pulsing.

Near-IR Two-Photon Fluorescent Sensor for K(+) Imaging in Live Cells.

Science.gov (United States)

Sui, Binglin; Yue, Xiling; Kim, Bosung; Belfield, Kevin D

2015-08-19

A new two-photon excited fluorescent K(+) sensor is reported. The sensor comprises three moieties, a highly selective K(+) chelator as the K(+) recognition unit, a boron-dipyrromethene (BODIPY) derivative modified with phenylethynyl groups as the fluorophore, and two polyethylene glycol chains to afford water solubility. The sensor displays very high selectivity (>52-fold) in detecting K(+) over other physiological metal cations. Upon binding K(+), the sensor switches from nonfluorescent to highly fluorescent, emitting red to near-IR (NIR) fluorescence. The sensor exhibited a good two-photon absorption cross section, 500 GM at 940 nm. Moreover, it is not sensitive to pH in the physiological pH range. Time-dependent cell imaging studies via both one- and two-photon fluorescence microscopy demonstrate that the sensor is suitable for dynamic K(+) sensing in living cells.

The Thermal Infrared Sensor onboard NASA's Mars 2020 Mission

Science.gov (United States)

Martinez, G.; Perez-Izquierdo, J.; Sebastian, E.; Ramos, M.; Bravo, A.; Mazo, M.; Rodriguez-Manfredi, J. A.

2017-12-01

NASA's Mars 2020 rover mission is scheduled for launch in July/August 2020 and will address key questions about the potential for life on Mars. The Mars Environmental Dynamics Analyzer (MEDA) is one of the seven instruments onboard the rover [1] and has been designed to assess the environmental conditions across the rover traverse. MEDA will extend the current record of in-situ meteorological measurements at the surface [2] to other locations on Mars. The Thermal InfraRed Sensor (TIRS) [3] is one of the six sensors comprising MEDA. TIRS will use three downward-looking channels to measure (1) the surface skin temperature (with high heritage from the Rover Environmental Monitoring Station onboard the Mars Science Laboratory mission [4]), (2) the upwelling thermal infrared radiation from the surface and (3) the reflected solar radiation at the surface, and two upward-looking channels to measure the (4) downwelling thermal infrared radiation at the surface and (5) the atmospheric temperature. In combination with other MEDA's sensors, TIRS will allow the quantification of the surface energy budget [5] and the determination of key geophysical properties of the terrain such as the albedo and thermal inertia with an unprecedented spatial resolution. Here we present a general description of the TIRS, with focus on its scientific requirements and results from field campaigns showing the performance of the different channels. References:[1] Rodríguez-Manfredi, J. A. et al. (2014), MEDA: An environmental and meteorological package for Mars 2020, LPSC, 45, 2837. [2] Martínez, G.M. et al. (2017), The Modern Near-Surface Martian Climate: A Review of In-situ Meteorological Data from Viking to Curiosity, Space Science Reviews, 1-44. [3] Pérez-Izquierdo, J. et al. (2017), The Thermal Infrared Sensor (TIRS) of the Mars Environmental Dynamics Analyzer (MEDA) Instrument onboard Mars 2020, IEEE. [4] Sebastián, E. et al. (2010), The Rover Environmental Monitoring Station Ground

Alignment and Calibration of Optical and Inertial Sensors Using Stellar Observations

National Research Council Canada - National Science Library

Veth, Mike; Raquet, John

2007-01-01

Aircraft navigation information (position, velocity, and attitude) can be determined using optical measurements from an imaging sensor pointed toward the ground combined with an inertial navigation system...

Airborne and satellite remote sensors for precision agriculture

Science.gov (United States)

Remote sensing provides an important source of information to characterize soil and crop variability for both within-season and after-season management despite the availability of numerous ground-based soil and crop sensors. Remote sensing applications in precision agriculture have been steadily inc...

A Review: Carbon Nanotube-Based Piezoresistive Strain Sensors

Directory of Open Access Journals (Sweden)

Waris Obitayo

2012-01-01

Full Text Available The use of carbon nanotubes for piezoresistive strain sensors has acquired significant attention due to its unique electromechanical properties. In this comprehensive review paper, we discussed some important aspects of carbon nanotubes for strain sensing at both the nanoscale and macroscale. Carbon nanotubes undergo changes in their band structures when subjected to mechanical deformations. This phenomenon makes them applicable for strain sensing applications. This paper signifies the type of carbon nanotubes best suitable for piezoresistive strain sensors. The electrical resistivities of carbon nanotube thin film increase linearly with strain, making it an ideal material for a piezoresistive strain sensor. Carbon nanotube composite films, which are usually fabricated by mixing small amounts of single-walled or multiwalled carbon nanotubes with selected polymers, have shown promising characteristics of piezoresistive strain sensors. Studies also show that carbon nanotubes display a stable and predictable voltage response as a function of temperature.

Data fusion for target tracking and classification with wireless sensor network

Science.gov (United States)

Pannetier, Benjamin; Doumerc, Robin; Moras, Julien; Dezert, Jean; Canevet, Loic

2016-10-01

In this paper, we address the problem of multiple ground target tracking and classification with information obtained from a unattended wireless sensor network. A multiple target tracking (MTT) algorithm, taking into account road and vegetation information, is proposed based on a centralized architecture. One of the key issue is how to adapt classical MTT approach to satisfy embedded processing. Based on track statistics, the classification algorithm uses estimated location, velocity and acceleration to help to classify targets. The algorithms enables tracking human and vehicles driving both on and off road. We integrate road or trail width and vegetation cover, as constraints in target motion models to improve performance of tracking under constraint with classification fusion. Our algorithm also presents different dynamic models, to palliate the maneuvers of targets. The tracking and classification algorithms are integrated into an operational platform (the fusion node). In order to handle realistic ground target tracking scenarios, we use an autonomous smart computer deposited in the surveillance area. After the calibration step of the heterogeneous sensor network, our system is able to handle real data from a wireless ground sensor network. The performance of system is evaluated in a real exercise for intelligence operation ("hunter hunt" scenario).

Molecular Sensors for Moisture Detection by Moessbauer Spectroscopy

International Nuclear Information System (INIS)

Renz, F.; Souza, P. A. de; Klingelhoefer, G.; Goodwin, H. A.

2002-01-01

A parameter of importance in various industrial and commercial applications is sensitivity to moisture. A new class of molecular sensors which enable the qualitative and quantitative determination of air moisture (high selectivity and sensitivity) by application of Moessbauer spectroscopy as the probe technique has been investigated. The electronic properties of the iron-containing sensor depend upon the presence of moisture which is taken up by it and this process is accompanied by a change in electronic spin ground state which can be detected by Moessbauer spectroscopy. The sensor is suitable for in-field and industrial application using the recently developed Moessbauer spectrometer MIMOS II. Possible suitability for the detection of moisture in extraterrestrial environments is considered.

Three-Axis Ground Reaction Force Distribution during Straight Walking.

Science.gov (United States)

Hori, Masataka; Nakai, Akihito; Shimoyama, Isao

2017-10-24

We measured the three-axis ground reaction force (GRF) distribution during straight walking. Small three-axis force sensors composed of rubber and sensor chips were fabricated and calibrated. After sensor calibration, 16 force sensors were attached to the left shoe. The three-axis force distribution during straight walking was measured, and the local features of the three-axis force under the sole of the shoe were analyzed. The heel area played a role in receiving the braking force, the base area of the fourth and fifth toes applied little vertical or shear force, the base area of the second and third toes generated a portion of the propulsive force and received a large vertical force, and the base area of the big toe helped move the body's center of mass to the other foot. The results demonstrate that measuring the three-axis GRF distribution is useful for a detailed analysis of bipedal locomotion.

Multiparametric methane sensor for environmental monitoring

Science.gov (United States)

Borecki, M.; Duk, M.; Kociubiński, A.; Korwin-Pawlowski, M. L.

2016-12-01

Today, methane sensors find applications mostly in safety alarm installations, gas parameters detection and air pollution classification. Such sensors and sensors elements exists for industry and home use. Under development area of methane sensors application is dedicated to ground gases monitoring. Proper monitoring of soil gases requires reliable and maintenance-free semi-constant and longtime examination at relatively low cost of equipment. The sensors for soil monitoring have to work on soil probe. Therefore, sensor is exposed to environment conditions, as a wide range of temperatures and a full scale of humidity changes, as well as rain, snow and wind, that are not specified for classical methane sensors. Development of such sensor is presented in this paper. The presented sensor construction consists of five commercial non dispersive infra-red (NDIR) methane sensing units, a set of temperature and humidity sensing units, a gas chamber equipped with a micro-fan, automated gas valves and also a microcontroller that controls the measuring procedure. The electronics part of sensor was installed into customized 3D printed housing equipped with self-developed gas valves. The main development of proposed sensor is on the side of experimental evaluation of construction reliability and results of data processing included safety procedures and function for hardware error correction. Redundant methane sensor units are used providing measurement error correction as well as improved measurement accuracy. The humidity and temperature sensors are used for internal compensation of methane measurements as well as for cutting-off the sensor from the environment when the conditions exceed allowable parameters. Results obtained during environment sensing prove that the gas concentration readings are not sensitive to gas chamber vertical or horizontal position. It is important as vertical sensor installation on soil probe is simpler that horizontal one. Data acquired during six

Integrated multi sensors and camera video sequence application for performance monitoring in archery

Science.gov (United States)

Taha, Zahari; Arif Mat-Jizat, Jessnor; Amirul Abdullah, Muhammad; Muazu Musa, Rabiu; Razali Abdullah, Mohamad; Fauzi Ibrahim, Mohamad; Hanafiah Shaharudin, Mohd Ali

2018-03-01

This paper explains the development of a comprehensive archery performance monitoring software which consisted of three camera views and five body sensors. The five body sensors evaluate biomechanical related variables of flexor and extensor muscle activity, heart rate, postural sway and bow movement during archery performance. The three camera views with the five body sensors are integrated into a single computer application which enables the user to view all the data in a single user interface. The five body sensors’ data are displayed in a numerical and graphical form in real-time. The information transmitted by the body sensors are computed with an embedded algorithm that automatically transforms the summary of the athlete’s biomechanical performance and displays in the application interface. This performance will be later compared to the pre-computed psycho-fitness performance from the prefilled data into the application. All the data; camera views, body sensors; performance-computations; are recorded for further analysis by a sports scientist. Our developed application serves as a powerful tool for assisting the coach and athletes to observe and identify any wrong technique employ during training which gives room for correction and re-evaluation to improve overall performance in the sport of archery.

RuO₂ pH Sensor with Super-Glue-Inspired Reference Electrode.

Science.gov (United States)

Lonsdale, Wade; Wajrak, Magdalena; Alameh, Kamal

2017-09-06

A pH-sensitive RuO₂ electrode coated in a commercial cyanoacrylate adhesive typically exhibits very low pH sensitivity, and could be paired with a RuO₂ working electrode as a differential type pH sensor. However, such sensors display poor performance in real sample matrices. A pH sensor employing a RuO₂ pH-sensitive working electrode and a SiO₂-PVB junction-modified RuO₂ reference electrode is developed as an alternative high-performance solution. This sensor exhibits a performance similar to that of a commercial glass pH sensor in some common sample matrices, particularly, an excellent pH sensitivity of 55.7 mV/pH, a hysteresis as low as 2.7 mV, and a drift below 2.2 mV/h. The developed sensor structure opens the way towards the development of a simple, cost effective, and robust pH sensor for pH analysis in various sample matrices.

Edge-assignment and figure-ground segmentation in short-term visual matching.

Science.gov (United States)

Driver, J; Baylis, G C

1996-12-01

Eight experiments examined the role of edge-assignment in a contour matching task. Subjects judged whether the jagged vertical edge of a probe shape matched the jagged edge that divided two adjoining shapes in an immediately preceding figure-ground display. Segmentation factors biased assignment of this dividing edge toward a figural shape on just one of its sides. Subjects were faster and more accurate at matching when the probe edge had a corresponding assignment. The rapid emergence of this effect provides an on-line analog of the long-term memory advantage for figures over grounds which Rubin (1915/1958) reported. The present on-line advantage was found when figures were defined by relative contrast and size, or by symmetry, and could not be explained solely by the automatic drawing of attention toward the location of the figural region. However, deliberate attention to one region of an otherwise ambiguous figure-ground display did produce the advantage. We propose that one-sided assignment of dividing edges may be obligatory in vision.

Ground robotic measurement of aeolian processes

Science.gov (United States)

Qian, Feifei; Jerolmack, Douglas; Lancaster, Nicholas; Nikolich, George; Reverdy, Paul; Roberts, Sonia; Shipley, Thomas; Van Pelt, R. Scott; Zobeck, Ted M.; Koditschek, Daniel E.

2017-08-01

Models of aeolian processes rely on accurate measurements of the rates of sediment transport by wind, and careful evaluation of the environmental controls of these processes. Existing field approaches typically require intensive, event-based experiments involving dense arrays of instruments. These devices are often cumbersome and logistically difficult to set up and maintain, especially near steep or vegetated dune surfaces. Significant advances in instrumentation are needed to provide the datasets that are required to validate and improve mechanistic models of aeolian sediment transport. Recent advances in robotics show great promise for assisting and amplifying scientists' efforts to increase the spatial and temporal resolution of many environmental measurements governing sediment transport. The emergence of cheap, agile, human-scale robotic platforms endowed with increasingly sophisticated sensor and motor suites opens up the prospect of deploying programmable, reactive sensor payloads across complex terrain in the service of aeolian science. This paper surveys the need and assesses the opportunities and challenges for amassing novel, highly resolved spatiotemporal datasets for aeolian research using partially-automated ground mobility. We review the limitations of existing measurement approaches for aeolian processes, and discuss how they may be transformed by ground-based robotic platforms, using examples from our initial field experiments. We then review how the need to traverse challenging aeolian terrains and simultaneously make high-resolution measurements of critical variables requires enhanced robotic capability. Finally, we conclude with a look to the future, in which robotic platforms may operate with increasing autonomy in harsh conditions. Besides expanding the completeness of terrestrial datasets, bringing ground-based robots to the aeolian research community may lead to unexpected discoveries that generate new hypotheses to expand the science

Status report on active stabilisation of a linear collider final focus quadrupole mock-up

International Nuclear Information System (INIS)

Lottin, J.; Brunetti, L.; Formosa, F.; Adloff, C.; Bastian, Y.; Bolzon, B.; Cadoux, F.; Geffroy, N.; Girard, C.; Jeremie, A.; Karyotakis, Y.; Peltier, F.

2006-01-01

The measurements done with the sensors available in our laboratories used for ground motion analysis are presented. The first sensors studied are seismic sensors measuring ground velocity, other sensors are accelerometers available for measuring ground acceleration. The first step has been to characterize the sensors, the second step has been to model and simulate the acceleration in order to identify Eigen frequencies and to display mode shapes. The third step has been to assess the performances of a new algorithm for disturbance rejection. In order to facilitate the analysis, a reduced-size mock-up has been used. The goal was to eliminate or at least to reduce as much as possible the main frequencies of the disturbance. A new mock-up is currently being developed that will have a geometry closer to a final focus quadrupole. Measurements will be done to validate the whole system in view of active stabilization for a future linear collider

Status report on active stabilisation of a linear collider final focus quadrupole mock-up

Energy Technology Data Exchange (ETDEWEB)

Lottin, J.; Brunetti, L.; Formosa, F. [Universite de Savoie, ESIA, 74 - Annecy (France); Adloff, C.; Bastian, Y.; Bolzon, B.; Cadoux, F.; Geffroy, N.; Girard, C.; Jeremie, A.; Karyotakis, Y.; Peltier, F. [LAPP-IN2P3-CNRS, 74 - Annecy-le-Vieux (France)

2006-07-01

The measurements done with the sensors available in our laboratories used for ground motion analysis are presented. The first sensors studied are seismic sensors measuring ground velocity, other sensors are accelerometers available for measuring ground acceleration. The first step has been to characterize the sensors, the second step has been to model and simulate the acceleration in order to identify Eigen frequencies and to display mode shapes. The third step has been to assess the performances of a new algorithm for disturbance rejection. In order to facilitate the analysis, a reduced-size mock-up has been used. The goal was to eliminate or at least to reduce as much as possible the main frequencies of the disturbance. A new mock-up is currently being developed that will have a geometry closer to a final focus quadrupole. Measurements will be done to validate the whole system in view of active stabilization for a future linear collider.

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.

Sensor integration and testing in an airborne environment

Science.gov (United States)

Ricks, Timothy P.; Streling, Julie T.; Williams, Kirk W.

2005-11-01

The U.S. Army Redstone Technical Test Center (RTTC) has been supporting captive flight testing of missile sensors and seekers since the 1980's. Successful integration and test of sensors in an airborne environment requires attention to a broad range of disciplines. Data collection requirements drive instrumentation and flight profile configurations, which along with cost and airframe performance factors influence the choice of test aircraft. Installation methods used for instrumentation must take into consideration environmental and airworthiness factors. In addition, integration of test equipment into the aircraft will require an airworthiness release; procedures vary between the government for military aircraft, and the Federal Aviation Administration (FAA) for the use of private, commercial, or experimental aircraft. Sensor mounting methods will depend on the type of sensor being used, both for sensor performance and crew safety concerns. Pilots will require navigation input to permit the execution of accurate and repeatable flight profiles. Some tests may require profiles that are not supported by standard navigation displays, requiring the use of custom hardware/software. Test locations must also be considered in their effect on successful data collection. Restricted airspace may also be required, depending on sensor emissions and flight profiles.

A below-ground herbivore shapes root defensive chemistry in natural plant populations

OpenAIRE

Huber, Meret; Bont, Zoe; Fricke, Julia; Brillatz, Th?o; Aziz, Zohra; Gershenzon, Jonathan; Erb, Matthias

2016-01-01

Plants display extensive intraspecific variation in secondary metabolites. However, the selective forces shaping this diversity remain often unknown, especially below ground. Using Taraxacum officinale and its major native insect root herbivore Melolontha melolontha, we tested whether below-ground herbivores drive intraspecific variation in root secondary metabolites. We found that high M. melolontha infestation levels over recent decades are associated with high concentrations of major root ...

Grounded Object and Grasp Representations in a Cognitive Architecture

DEFF Research Database (Denmark)

Kraft, Dirk

developed. This work presents a system that is able to learn autonomously about objects and applicable grasps in an unknown environment through exploratory manipulation and to then use this grounded knowledge in a planning setup to address complex tasks. A set of different subsystems is needed to achieve....... The topics are ordered so that we proceed from the more general integration works towards the works describing the individual components. The first chapter gives an overview over the system that is able to learn a grounded visual object representation and a grounded grasp representation. In the following...... part, we describe how this grounding procedures can be embedded in a three cognitive level architecture. Our initial work to use a tactile sensor to enrichen the object representations as well as allow for more complex actions is presented here as well. Since our system is concerned with learning about...

Development of TGS2611 methane sensor and SHT11 humidity and temperature sensor for measuring greenhouse gas on peatlands in south kalimantan, indonesia

Science.gov (United States)

Sugriwan, I.; Soesanto, O.

2017-05-01

The research was focused on development of data acquisition system to monitor the content of methane, relative humidity and temperature on peatlands in South Kalimantan, Indonesia. Methane is one of greenhouse gases that emitted from peatlands; while humidity and temperature are important parameters of microclimate on peatlands. The content of methane, humidity and temperature are three parameters were monitored digitally, real time, continuously and automatically record by data acquisition systems that interfaced to the personal computer. The hardware of data acquisition system consists of power supply unit, TGS2611 methane gas sensor, SHT11 humidity and temperature sensors, voltage follower, ATMega8535 microcontroller, 16 × 2 LCD character and personal computer. ATMega8535 module is a device to manage all part in measuring instrument. The software which is responsible to take sensor data, calculate characteristic equation and send data to 16 × 2 LCD character are Basic Compiler. To interface between measuring instrument and personal computer is maintained by Delphi 7. The result of data acquisition showed on 16 × 2 LCD characters, PC monitor and database with developed by XAMPP. Methane, humidity, and temperature which release from peatlands are trapped by Closed-Chamber Measurement with dimension 60 × 50 × 40 cm3. TGS2611 methane gas sensor and SHT11 humidity and temperature sensor are calibrated to determine transfer function used to data communication between sensors and microcontroller and integrated into ATMega8535 Microcontroller. Calculation of RS and RL of TGS2611 methane gas sensor refer to data sheet and obtained respectively 1360 ohm and 905 ohm. The characteristic equation of TGS2611 satisfies equation VRL = 0.561 ln n - 2.2641 volt, with n is a various concentrations and VRL in volt. The microcontroller maintained the voltage signal than interfaced it to liquid crystal displays and personal computer (laptop) to display result of the measurement

Development of TGS2611 methane sensor and SHT11 humidity and temperature sensor for measuring greenhouse gas on peatlands in South Kalimantan, indonesia

International Nuclear Information System (INIS)

Sugriwan, I; Soesanto, O

2017-01-01

The research was focused on development of data acquisition system to monitor the content of methane, relative humidity and temperature on peatlands in South Kalimantan, Indonesia. Methane is one of greenhouse gases that emitted from peatlands; while humidity and temperature are important parameters of microclimate on peatlands. The content of methane, humidity and temperature are three parameters were monitored digitally, real time, continuously and automatically record by data acquisition systems that interfaced to the personal computer. The hardware of data acquisition system consists of power supply unit, TGS2611 methane gas sensor, SHT11 humidity and temperature sensors, voltage follower, ATMega8535 microcontroller, 16 × 2 LCD character and personal computer. ATMega8535 module is a device to manage all part in measuring instrument. The software which is responsible to take sensor data, calculate characteristic equation and send data to 16 × 2 LCD character are Basic Compiler. To interface between measuring instrument and personal computer is maintained by Delphi 7. The result of data acquisition showed on 16 × 2 LCD characters, PC monitor and database with developed by XAMPP. Methane, humidity, and temperature which release from peatlands are trapped by Closed-Chamber Measurement with dimension 60 × 50 × 40 cm 3 . TGS2611 methane gas sensor and SHT11 humidity and temperature sensor are calibrated to determine transfer function used to data communication between sensors and microcontroller and integrated into ATMega8535 Microcontroller. Calculation of RS and RL of TGS2611 methane gas sensor refer to data sheet and obtained respectively 1360 ohm and 905 ohm. The characteristic equation of TGS2611 satisfies equation V RL = 0.561 ln n – 2.2641 volt, with n is a various concentrations and V RL in volt. The microcontroller maintained the voltage signal than interfaced it to liquid crystal displays and personal computer (laptop) to display result of the

Electro-optic architecture for servicing sensors and actuators in advanced aircraft propulsion systems

Science.gov (United States)

Poppel, G. L.; Glasheen, W. M.

1989-01-01

A detailed design of a fiber optic propulsion control system, integrating favored sensors and electro-optics architecture is presented. Layouts, schematics, and sensor lists describe an advanced fighter engine system model. Components and attributes of candidate fiber optic sensors are identified, and evaluation criteria are used in a trade study resulting in favored sensors for each measurand. System architectural ground rules were applied to accomplish an electro-optics architecture for the favored sensors. A key result was a considerable reduction in signal conductors. Drawings, schematics, specifications, and printed circuit board layouts describe the detailed system design, including application of a planar optical waveguide interface.

IR Sensor Synchronizing Active Shutter Glasses for 3D HDTV with Flexible Liquid Crystal Lenses

Directory of Open Access Journals (Sweden)

Jeong In Han

2013-12-01

Full Text Available IR sensor synchronizing active shutter glasses for three-dimensional high definition television (3D HDTV were developed using a flexible liquid crystal (FLC lens. The FLC lens was made on a polycarbonate (PC substrate using conventional liquid crystal display (LCD processes. The flexible liquid crystal lens displayed a maximum transmission of 32% and total response time of 2.56 ms. The transmittance, the contrast ratio and the response time of the flexible liquid crystal lens were superior to those of glass liquid crystal lenses. Microcontroller unit and drivers were developed as part of a reception module with power supply for the IR sensor synchronizing active shutter glasses with the flexible liquid crystal lens prototypes. IR sensor synchronizing active shutter glasses for 3D HDTV with flexible liquid crystal lenses produced excellent 3D images viewing characteristics.

Application of parallelized software architecture to an autonomous ground vehicle

Science.gov (United States)

Shakya, Rahul; Wright, Adam; Shin, Young Ho; Momin, Orko; Petkovsek, Steven; Wortman, Paul; Gautam, Prasanna; Norton, Adam

2011-01-01

This paper presents improvements made to Q, an autonomous ground vehicle designed to participate in the Intelligent Ground Vehicle Competition (IGVC). For the 2010 IGVC, Q was upgraded with a new parallelized software architecture and a new vision processor. Improvements were made to the power system reducing the number of batteries required for operation from six to one. In previous years, a single state machine was used to execute the bulk of processing activities including sensor interfacing, data processing, path planning, navigation algorithms and motor control. This inefficient approach led to poor software performance and made it difficult to maintain or modify. For IGVC 2010, the team implemented a modular parallel architecture using the National Instruments (NI) LabVIEW programming language. The new architecture divides all the necessary tasks - motor control, navigation, sensor data collection, etc. into well-organized components that execute in parallel, providing considerable flexibility and facilitating efficient use of processing power. Computer vision is used to detect white lines on the ground and determine their location relative to the robot. With the new vision processor and some optimization of the image processing algorithm used last year, two frames can be acquired and processed in 70ms. With all these improvements, Q placed 2nd in the autonomous challenge.

Fiber-optic sensors for rapid, inexpensive characterization of soil and ground water contamination

International Nuclear Information System (INIS)

Milanovich, F.P.; Yow, J.L. Jr.

1994-08-01

The extent and complexity of worldwide environmental contamination are great enough that characterization, remediation, and performance monitoring will be extremely costly and lengthy. Characterization techniques that are rapid, inexpensive, and simple and that do not generate waste are urgently needed. Towards this end LLNL is developing a fiber-optic chemical sensor technology for use in groundwater and vadose-zone monitoring. We use a colorimetric detection technique, based on an irreversible chemical reaction between a specific reagent and the target compound. The accuracy and sensitivity of the sensor (<5 ppb by weight in water, determined by comparison with gas chromatographic standard measurements) are sufficient for environmental monitoring of trichloroethylene (TCE) and chloroform

Monitoring System for Slope Stability under Rainfall by using MEMS Acceleration Sensor IC tags

International Nuclear Information System (INIS)

Murakami, S; Dairaku, A; Komine, H; Saito, O; Sakai, N; Isizawa, T; Maruyama, I

2013-01-01

Real-time warning system for slope failure under rainfall is available to disaster prevention and mitigation. Monitoring of multi-point and wireless measurements is effective because it is difficult to conclude the most dangerous part in a slope. The purpose of this study is to propose a method of monitoring system with multi-point and wireless measurements for a slope stability using MEMS acceleration sensor IC tags. MEMS acceleration sensor IC tag is an acceleration sensor microminiaturized by a technology of Micro Electro Mechanical Systems on board IC tag. Especially, low cost of the sensor will yield to the realization of the system. In order to investigate the applicability of the proposed system, a large-scale model test of artificial slope subjected to rainfall has been performed. MEMS acceleration sensor IC tags has been located on the slope and ground acceleration caused by forced vibration has been measured until the model slope collapses. The experimental results show that the MEMS acceleration sensor IC tag is comfortably available under rainfall, the characteristics of ground accelerations varies with changing the condition of the slope subjected to rainfall, and the proposed method can be applied to a real-time monitoring system for slope failure under rainfall.

Quinoline group based fluorescent sensor for detecting zinc ions in aqueous media and its logic gate behaviour

International Nuclear Information System (INIS)

Dong, Zhengping; Guo, Yueping; Tian, Xin; Ma, Jiantai

2013-01-01

A highly sensitive method for quantitative determination of Zn 2+ in water has been developed by using a novel fluorescent sensor NQA: (N-Quinolin-8-yl-2-[(quinolin-8-ylcarbamoylmethyl)-amino]-acetamide). The sensor displays great selectivity for Zn 2+ in the presence of other metal ions in aqueous solution and possesses an excellent sensitivity of about 2×10 −8 M for Zn 2+ . The binding stoichiometry, binding affinity, and pH sensitivity of the sensor have also been studied. Furthermore, the fluorescent changes of NQA upon the addition of cations (Cu 2+ and Zn 2+ ) are utilized to construct an INHIBIT logic gate at the molecular level, using Cu 2+ and Zn 2+ as chemical inputs and the fluorescence intensity as output. NQA has ideal chemical and spectroscopic properties that satisfy the criteria for further biological and environmental applications. - Highlights: ► A novel fluorescent sensor for Zn 2+ in water has been synthesized. ► The sensor displays high selectivity for Zn 2+ in the presence of other ions. ► The sensor exhibits excellent sensing ability under the physiological pH window. ► The sensor can be utilized as an INHIBIT logic gate at the molecular level.

Application of Open Garden Sensor on Hydroponic Maintenance Management

Science.gov (United States)

Nasution, S.; Siregar, B.; Kurniawan, M.; Pranoto, H.; Andayani, U.; Fahmi, F.

2018-03-01

Hydroponic farming system is an agricultural system that uses direct water as a nutrient without using soil as a planting medium. This system allows smallholder farmers to have the opportunity to develop their crop production with less capital. In addition, hydroponic planting has also been widely adapted by individuals as a personal hobby. Application of technology has penetrated various fields including agricultural fields. One of the technologies that can be applied in a hydroponic farming system is the sensor. Sensors are devices that used to convert a physical quantity into a quantity of electricity so that it can be analyse with a certain electrical circuit. In this study, the technology to be applied is wireless sensor technology applied in human life to help get information quickly and accurately. Sensors to be used in this study are pH sensors, conductivity sensors, temperature sensors and humidity. In addition to sensors, the study also involved Arduino technology. Arduino is a microcontroller board that is used to interact with the environment based on programs that have been made. The final results of the application testing show that the system success to display diagram in real-time in an environment from Arduino board to database and web server.

Programmable System-on-Chip (PSoC) Embedded Readout Designs for Liquid Helium Level Sensors.

Science.gov (United States)

Parasakthi, C; Gireesan, K; Usha Rani, R; Sheela, O K; Janawadkar, M P

2014-08-01

This article reports the development of programmable system-on-chip (PSoC)-based embedded readout designs for liquid helium level sensors using resistive liquid vapor discriminators. The system has been built for the measurement of liquid helium level in a concave-bottomed, helmet-shaped, fiber-reinforced plastic cryostat for magnetoencephalography. This design incorporates three carbon resistors as cost-effective sensors, which are mounted at desired heights inside the cryostat and were used to infer the liquid helium level by measuring their temperature-dependent resistance. Localized electrical heating of the carbon resistors was used to discriminate whether the resistor is immersed in liquid helium or its vapor by exploiting the difference in the heat transfer rates in the two environments. This report describes a single PSoC chip for the design and development of a constant current source to drive the three carbon resistors, a multiplexer to route the sensor outputs to the analog-to-digital converter (ADC), a buffer to avoid loading of the sensors, an ADC for digitizing the data, and a display using liquid crystal display cum light-emitting diode modules. The level sensor readout designed with a single PSoC chip enables cost-effective and reliable measurement system design. © 2014 Society for Laboratory Automation and Screening.

Pioneer Venus Star Sensor. [active despin control application

Science.gov (United States)

Gutshall, R. L.; Thomas, G.

1979-01-01

The design predictions and orbital performance verification of the solid state star scanner used in the Onboard Attitude Control of the Pioneer Venus Orbiter and Multiprobe are presented. The star sensor extended the scanner use to active despin control, and it differs from previous sensors in solid state detection, redundant electronics for reliability, larger field of view, and large dynamic spin range. The star scanner hardware and design performance based on the ability to predict all noise sources, signal magnitudes, and expected detection probability are discussed. In-flight data collected to verify sensor ground calibration are tabulated and plotted in predicted accuracy curves. It is concluded that the Pioneer Venus Star Sensor has demonstrated predictable star calibration in the range of .1 magnitude uncertainties and usable star catalogs of 100 stars with very high probabilities of detection, which were much better than expected and well within the mission requirements.

Design of Early Warning System Based on Wireless Sensor Network

Directory of Open Access Journals (Sweden)

Gan Bo

2018-01-01

Full Text Available In order to solve the shortcomings of the landslide monitoring technology method, a set of landslides monitoring and early warning system is designed. It can achieve real-time sensor data acquisition, remote transmission and query display. In addition, aiming at the harsh environment of landslide monitoring and the performance requirements of the monitoring system, an improved minimum hop routing protocol is proposed. It can reduce network energy consumption, enhance network robustness, and improve node layout and networking flexibility. In order to realize the remote transmission of data, GPRS wireless communication is used to transmit monitoring data. Combined with remote monitoring center, real-time data display, query, preservation and landslide warning and prediction are realized. The results show that the sensor data acquisition system is accurate, the system is stable, and the node network is flexible. Therefore, the monitoring system has a good use value.

Novel Magnetic and Chemical Micro Sensors for In-situ, Real-time, and Unattended Use

International Nuclear Information System (INIS)

Datskou, I.

2001-01-01

There exists a need to develop novel, advanced, unattended magnetic and chemical micro-sensor systems for successful detection, localization, classification and tracking of ground time critical targets of interest. Consistent with the underlying long-term objectives of the development of unattended ground sensors (UGS) program they have investigated the use of a new planted ground sensor platform based on Micro-Electro-Mechanical Systems (MEMS) that can offer magnetic, chemical and possibly acoustic detection. The envisioned micro-system will be low-power and low-cost and will be built around a single type of microstructure element integrating a monolithic optical system and electronics package. This micro sensor can also incorporate burst telemetry to transmit the information, a renewable power source and will be capable of operating under field conditions, with sufficient sensitivity to permit high detection rates, and with sufficient chemical selectivity to prevent high false alarm rates. Preliminary studies, initial designs, and key predicted performance parameters will be presented. Possible applications of such a system include sensitive perimeter monitoring such as minefields and military/nuclear bases, vehicle detection, and aircraft navigation systems, and drug enforcement operations. The results of the present work demonstrate that the microcalorimetric spectroscopy technique can be applied to detect and identify chemicals in the ppm level and the studied microcantilever-based magnetometer can provide sensitivities in the order of 1(micro)T

Biased figure-ground assignment affects conscious object recognition in spatial neglect.

Science.gov (United States)

Eramudugolla, Ranmalee; Driver, Jon; Mattingley, Jason B

2010-09-01

Unilateral spatial neglect is a disorder of attention and spatial representation, in which early visual processes such as figure-ground segmentation have been assumed to be largely intact. There is evidence, however, that the spatial attention bias underlying neglect can bias the segmentation of a figural region from its background. Relatively few studies have explicitly examined the effect of spatial neglect on processing the figures that result from such scene segmentation. Here, we show that a neglect patient's bias in figure-ground segmentation directly influences his conscious recognition of these figures. By varying the relative salience of figural and background regions in static, two-dimensional displays, we show that competition between elements in such displays can modulate a neglect patient's ability to recognise parsed figures in a scene. The findings provide insight into the interaction between scene segmentation, explicit object recognition, and attention.

RuO2 pH Sensor with Super-Glue-Inspired Reference Electrode

Directory of Open Access Journals (Sweden)

Wade Lonsdale

2017-09-01

Full Text Available A pH-sensitive RuO2 electrode coated in a commercial cyanoacrylate adhesive typically exhibits very low pH sensitivity, and could be paired with a RuO2 working electrode as a differential type pH sensor. However, such sensors display poor performance in real sample matrices. A pH sensor employing a RuO2 pH-sensitive working electrode and a SiO2-PVB junction-modified RuO2 reference electrode is developed as an alternative high-performance solution. This sensor exhibits a performance similar to that of a commercial glass pH sensor in some common sample matrices, particularly, an excellent pH sensitivity of 55.7 mV/pH, a hysteresis as low as 2.7 mV, and a drift below 2.2 mV/h. The developed sensor structure opens the way towards the development of a simple, cost effective, and robust pH sensor for pH analysis in various sample matrices.

RuO2 pH Sensor with Super-Glue-Inspired Reference Electrode

Science.gov (United States)

Wajrak, Magdalena; Alameh, Kamal

2017-01-01

A pH-sensitive RuO2 electrode coated in a commercial cyanoacrylate adhesive typically exhibits very low pH sensitivity, and could be paired with a RuO2 working electrode as a differential type pH sensor. However, such sensors display poor performance in real sample matrices. A pH sensor employing a RuO2 pH-sensitive working electrode and a SiO2-PVB junction-modified RuO2 reference electrode is developed as an alternative high-performance solution. This sensor exhibits a performance similar to that of a commercial glass pH sensor in some common sample matrices, particularly, an excellent pH sensitivity of 55.7 mV/pH, a hysteresis as low as 2.7 mV, and a drift below 2.2 mV/h. The developed sensor structure opens the way towards the development of a simple, cost effective, and robust pH sensor for pH analysis in various sample matrices. PMID:28878182

Development of an Intelligent Capacitive Mass Sensor Based on Co-axial Cylindrical Capacitor

Directory of Open Access Journals (Sweden)

Amir ABU AL AISH

2009-06-01

Full Text Available The paper presents a linear, robust and intelligent capacitive mass sensor made of a co-axial cylindrical capacitor. It is designed such that the mass under measurement is directly proportional to the capacitance of the sensor. The average value of the output voltage of a capacitance to voltage converter is proportional to the capacitance of the sensor. The output of the converter is measured and displayed, as mass, with the help of microcontroller. The results are free from the effect of stray capacitances which cause errors at low values of capacitances. Developed sensor is linear, free from errors due to temperature and highly flexible in design. The proto-type of the mass sensor can weigh up to 4 kilogram only.

Hyperspectral Sensors Final Report CRADA No. TC02173.0

Energy Technology Data Exchange (ETDEWEB)

Priest, R. E. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Sauvageau, J. E. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

2017-08-30

This was a collaborative effort between Lawrence Livermore National Security, LLC as manager and operator of Lawrence Livermore National Laboratory (LLNL) and Science Applications International Corporation (SAIC), National Security Space Operations/SRBU, to develop longwave infrared (LWIR) hyperspectral imaging (HSI) sensors for airborne and potentially ground and space, platforms. LLNL has designed and developed LWIR HSI sensors since 1995. The current generation of these sensors has applications to users within the U.S. Department of Defense and the Intelligence Community. User needs are for multiple copies provided by commercial industry. To gain the most benefit from the U.S. Government’s prior investments in LWIR HSI sensors developed at LLNL, transfer of technology and know-how from LLNL HSI experts to commercial industry was needed. The overarching purpose of the CRADA project was to facilitate the transfer of the necessary technology from LLNL to SAIC thereby allowing the U.S. Government to procure LWIR HSI sensors from this company.

Microwave Metamaterial-Based Sensor for Dielectric Characterization of Liquids.

Science.gov (United States)

Soffiatti, André; Max, Yuri; G Silva, Sandro; M de Mendonça, Laércio

2018-05-11

This article proposed to build a system founded on metamaterial sensor antennas, which can be used to evaluate impurities in aqueous substances according to the quality of transmission between the sensor antennas. In order to do this, a dedicated setup with tests in several frequencies was deployed so as to monitor the behavior of transmission variation between sensors. These sensors are microstrip antennas with a ground plane of resonant cleaved metallic rings; the substrate functions as a metamaterial for the irradiating element. In this study, an analysis was made of transmission between the sensors, looking for variation in angles of incidence of signal and of distance between the antennas. The sensor was tested at various operating frequencies, as such 1.8 GHz, 2.4 GHz, 3.4 GHz and 4.1 GHz, resulting in different values of sensitivity. The prototypes were constructed and tested so as to analyze the dielectric effects of the impurities on NaCl and C₂H₄O₂ substances. The research aims to use these control systems of impurities in industrial premises.

CONCEPTUAL DESIGN OF MONITORING AND CONTROL SUBSYSTEM FOR GNSS GROUND STATION

Directory of Open Access Journals (Sweden)

Seongkyun Jeong

2007-12-01

Full Text Available The Global Navigation Satellite System (GNSS becomes more important and is applied to various systems. Recently, the Galileo navigation system is being developed in Europe. Also, other countries like China, Japan and India are developing the global/regional navigation satellite system. As various global/regional navigation satellite systems are used, the navigation ground system gets more important for using the navigation system reasonably and efficiently. According to this trend, the technology of GNSS Ground Station (GGS is developing in many fields. The one of purposes for this study is to develop the high precision receiver for GNSS sensor station and to provide ground infrastructure for better performance services on navigation system. In this study, we consider the configuration of GNSS Ground Station and analyze function of Monitoring and Control subsystem which is a part of GNSS Ground Station. We propose Monitoring and Control subsystem which contains the navigation software for GNSS Ground System to monitor and control equipments in GNSS Ground Station, to spread the applied field of navigation system, and to provide improved navigation information to user.

The role of shape recognition in figure/ground perception in infancy.

Science.gov (United States)

White, Hannah; Jubran, Rachel; Heck, Alison; Chroust, Alyson; Bhatt, Ramesh S

2018-04-30

In this study we sought to determine whether infants, like adults, utilize previous experience to guide figure/ground processing. After familiarization to a shape, 5-month-olds preferentially attended to the side of an ambiguous figure/ground test stimulus corresponding to that shape, suggesting that they were viewing that portion as the figure. Infants' failure to exhibit this preference in a control condition in which both sides of the test stimulus were displayed as figures indicated that the results in the experimental condition were not due to a preference between two figure shapes. These findings demonstrate for the first time that figure/ground processing in infancy is sensitive to top-down influence. Thus, a critical aspect of figure/ground processing is functional early in life.

Correlating Multimodal Physical Sensor Information with Biological Analysis in Ultra Endurance Cycling

Directory of Open Access Journals (Sweden)

Giles D.Warrington

2010-07-01

Full Text Available The sporting domain has traditionally been used as a testing ground for new technologies which subsequently make their way into the public domain. This includes sensors. In this article a range of physical and biological sensors deployed in a 64 hour ultra-endurance non-stop cycling race are described. A novel algorithm to estimate the energy expenditure while cycling and resting during the event are outlined. Initial analysis in this noisy domain of “sensors in the field” are very encouraging and represent a first with respect to cycling.

A miniature sensor for electrical field measurements in dusty planetary atmospheres

International Nuclear Information System (INIS)

Renno, N O; Rogacki, S; Kok, J F; Kirkham, H

2008-01-01

Dusty phenomena such as regular wind-blown dust, dust storms, and dust devils are the most important, currently active, geological processes on Mars. Electric fields larger than 100 kV/m have been measured in terrestrial dusty phenomena. Theoretical calculations predict that, close to the surface, the bulk electric fields in martian dusty phenomena reach the breakdown value of the isolating properties of thin martian air of about a few 10 kV/m. The fact that martian dusty phenomena are electrically active has important implications for dust lifting and atmospheric chemistry. Electric field sensors are usually grounded and distort the electric fields in their vicinity. Grounded sensors also produce large errors when subject to ion currents or impacts from clouds of charged particles. Moreover, they are incapable of providing information about the direction of the electric field, an important quantity. Finally, typical sensors with more than 10 cm of diameter are not capable of measuring electric fields at distances as small as a few cm from the surface. Measurements this close to the surface are necessary for studies of the effects of electric fields on dust lifting. To overcome these shortcomings, we developed the miniature electric-field sensor described in this article.

MEMS based Low Cost Piezoresistive Microcantilever Force Sensor and Sensor Module.

Science.gov (United States)

Pandya, H J; Kim, Hyun Tae; Roy, Rajarshi; Desai, Jaydev P

2014-03-01

In the present work, we report fabrication and characterization of a low-cost MEMS based piezoresistive micro-force sensor with SU-8 tip using laboratory made silicon-on-insulator (SOI) substrate. To prepare SOI wafer, silicon film (0.8 µm thick) was deposited on an oxidized silicon wafer using RF magnetron sputtering technique. The films were deposited in Argon (Ar) ambient without external substrate heating. The material characteristics of the sputtered deposited silicon film and silicon film annealed at different temperatures (400-1050°C) were studied using atomic force microscopy (AFM) and X-ray diffraction (XRD) techniques. The residual stress of the films was measured as a function of annealing temperature. The stress of the as-deposited films was observed to be compressive and annealing the film above 1050°C resulted in a tensile stress. The stress of the film decreased gradually with increase in annealing temperature. The fabricated cantilevers were 130 µm in length, 40 µm wide and 1.0 µm thick. A series of force-displacement curves were obtained using fabricated microcantilever with commercial AFM setup and the data were analyzed to get the spring constant and the sensitivity of the fabricated microcantilever. The measured spring constant and sensitivity of the sensor was 0.1488N/m and 2.7mV/N. The microcantilever force sensor was integrated with an electronic module that detects the change in resistance of the sensor with respect to the applied force and displays it on the computer screen.

Planar location of the simulative acoustic source based on fiber optic sensor array

Science.gov (United States)

Liang, Yi-Jun; Liu, Jun-feng; Zhang, Qiao-ping; Mu, Lin-lin

2010-06-01

A fiber optic sensor array which is structured by four Sagnac fiber optic sensors is proposed to detect and locate a simulative source of acoustic emission (AE). The sensing loops of Sagnac interferometer (SI) are regarded as point sensors as their small size. Based on the derived output light intensity expression of SI, the optimum work condition of the Sagnac fiber optic sensor is discussed through the simulation of MATLAB. Four sensors are respectively placed on a steel plate to structure the sensor array and the location algorithms are expatiated. When an impact is generated by an artificial AE source at any position of the plate, the AE signal will be detected by four sensors at different times. With the help of a single chip microcomputer (SCM) which can calculate the position of the AE source and display it on LED, we have implemented an intelligent detection and location.

Soil chemical sensor and precision agricultural chemical delivery system and method

Science.gov (United States)

Colburn, Jr., John W.

1991-01-01

A real time soil chemical sensor and precision agricultural chemical delivery system includes a plurality of ground-engaging tools in association with individual soil sensors which measure soil chemical levels. The system includes the addition of a solvent which rapidly saturates the soil/tool interface to form a conductive solution of chemicals leached from the soil. A multivalent electrode, positioned within a multivalent frame of the ground-engaging tool, applies a voltage or impresses a current between the electrode and the tool frame. A real-time soil chemical sensor and controller senses the electrochemical reaction resulting from the application of the voltage or current to the leachate, measures it by resistivity methods, and compares it against pre-set resistivity levels for substances leached by the solvent. Still greater precision is obtained by calibrating for the secondary current impressed through solvent-less soil. The appropriate concentration is then found and the servo-controlled delivery system applies the appropriate amount of fertilizer or agricultural chemicals substantially in the location from which the soil measurement was taken.

A new selectophore for gadolinium selective sensor

International Nuclear Information System (INIS)

Zamani, Hassan Ali; Faridbod, Farnoush; Ganjali, Mohammad Reza

2014-01-01

Based on a selective complexation of N′-(2-oxo-1,2-di(pyridin-2-yl)ethylidene)furan-2-carbohydrazide (L) with Gd(III) ions, it was used as a selectophore in construction of a Gd(III) selective PVC membrane sensor. Different compositions for the membrane were tested. The o-nitrophenyloctyl ether (NPOE) was used as suitable plasticizer, and a mixture of sodium tetraphenyl borate (NaTPB) and oleic acid (OA) as anion excluders. The proposed sensor displayed a Nernstian behavior with the slope of 19.9 ± 0.6 mV decade −1 in concentration range of 1.0 × 10 −6 to 1.0 × 10 −2 mol L −1 . Detection limit was 4.2 × 10 −7 mol L −1 and response time was ∼ 10 s. Applicable pH range of the electrode was 4.2–8.0. Lifetime of the sensor is at least 10 weeks. Analysis of certified reference materials confirmed the accuracy of the proposed electrode. - Highlights: • This work reports design of membrane sensor for monitoring of Gd3+ ions. • The novelty of this work is the high affinity of the ionophore toward the Gd3+ ions. • The sensor is superior to the formerly reported Gd3+ sensors in terms of selectivity

Fabrication and Evaluation of a Graphene Oxide-Based Capacitive Humidity Sensor.

Science.gov (United States)

Feng, Jinfeng; Kang, Xiaoxu; Zuo, Qingyun; Yuan, Chao; Wang, Weijun; Zhao, Yuhang; Zhu, Limin; Lu, Hanwei; Chen, Juying

2016-03-01

In this study, a CMOS compatible capacitive humidity sensor structure was designed and fabricated on a 200 mm CMOS BEOL Line. A top Al interconnect layer was used as an electrode with a comb/serpent structure, and graphene oxide (GO) was used as sensing material. XRD analysis was done which shows that GO sensing material has a strong and sharp (002) peak at about 10.278°, whereas graphite has (002) peak at about 26°. Device level CV and IV curves were measured in mini-environments at different relative humidity (RH) level, and saturated salt solutions were used to build these mini-environments. To evaluate the potential value of GO material in humidity sensor applications, a prototype humidity sensor was designed and fabricated by integrating the sensor with a dedicated readout ASIC and display/calibration module. Measurements in different mini-environments show that the GO-based humidity sensor has higher sensitivity, faster recovery time and good linearity performance. Compared with a standard humidity sensor, the measured RH data of our prototype humidity sensor can match well that of the standard product.

Microfluidic EBG Sensor Based on Phase-Shift Method Realized Using 3D Printing Technology

Directory of Open Access Journals (Sweden)

Vasa Radonić

2017-04-01

Full Text Available In this article, we propose a novel microfluidic microstrip electromagnetic band gap (EBG sensor realized using cost-effective 3D printing technology. Microstrip sensor allows monitoring of the fluid properties flowing in the microchannel embedded between the microstrip line and ground plane. The sensor’s operating principle is based on the phase-shift method, which allows the characterization at a single operating frequency of 6 GHz. The defected electromagnetic band gap (EBG structure is realized as a pattern in the microstrip ground plane to improve sensor sensitivity. The designed microfluidic channel is fabricated using a fused deposition modelling (FDM 3D printing process without additional supporting layers, while the conductive layers are realized using sticky aluminium tape. The measurement results show that the change of permittivity of the fluid in the microfluidic channel from 1 to 80 results in the phase-shift difference of almost 90°. The potential application is demonstrated through the implementation of a proposed sensor for the detection of toluene concentration in toluene–methanol mixture where various concentrations of toluene were analysed.

Upper Limb Kinematics Using Inertial and Magnetic Sensors: Comparison of Sensor-to-Segment Calibrations

Directory of Open Access Journals (Sweden)

Brice Bouvier

2015-07-01

Full Text Available Magneto-Inertial Measurement Unit sensors (MIMU display high potential for the quantitative evaluation of upper limb kinematics, as they allow monitoring ambulatory measurements. The sensor-to-segment calibration step, consisting of establishing the relation between MIMU sensors and human segments, plays an important role in the global accuracy of joint angles. The aim of this study was to compare sensor-to-segment calibrations for the MIMU-based estimation of wrist, elbow, and shoulder joint angles, by examining trueness (“close to the reference” and precision (reproducibility validity criteria. Ten subjects performed five sessions with three different operators. Three classes of calibrations were studied: segment axes equal to technical MIMU axes (TECH, segment axes generated during a static pose (STATIC, and those generated during functional movements (FUNCT. The calibrations were compared during the maximal uniaxial movements of each joint, plus an extra multi-joint movement. Generally, joint angles presented good trueness and very good precision in the range 5°–10°. Only small discrepancy between calibrations was highlighted, with the exception of a few cases. The very good overall accuracy (trueness and precision of MIMU-based joint angle data seems to be more dependent on the level of rigor of the experimental procedure (operator training than on the choice of calibration itself.

Audio-Haptic Simulation of Walking on Virtual Ground Surfaces to Enhance Realism

DEFF Research Database (Denmark)

Nilsson, Niels Christian; Nordahl, Rolf; Turchet, Luca

2012-01-01

on a platform overlooking a canyon. Subjects were asked to visit the environment wearing an head-mounted display and a custom made pair of sandals enhanced with sensors and actuators. A 12-channels surround sound system delivered a soundscape which was consistent with the visual environment. In the first...

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.

Planar sensors for the upgrade of the CMS pixel detector

International Nuclear Information System (INIS)

Rohe, T.; Bean, A.; Radicci, V.; Sibille, J.

2011-01-01

A replacement of the present CMS pixel detector with a better performing light weight four-layer system is foreseen in 2016. In the lifetime of this new system the LHC will reach and exceed its nominal luminosity of 10 34 cm -2 s -1 . Therefore the radiation hardness of all parts of the pixel system has to be reviewed. For the construction of the much larger four-layer pixel system, the replacement of the present double sided sensors by much cheaper single sided ones is considered. However, the construction of pixel modules with such sensors is challenging due to the small geometrical distance of the sensor high voltage and the ground of the readout electronics. This small distance limits the sensor bias to about 500 V in the tested samples.

Fluxgate vector magnetometers: Compensated multi-sensor devices for ground, UAV and airborne magnetic survey for various application in near surface geophysics

Science.gov (United States)

Gavazzi, Bruno; Le Maire, Pauline; Munschy, Marc; Dechamp, Aline

2017-04-01

Fluxgate 3-components magnetometer is the kind of magnetometer which offers the lightest weight and lowest power consumption for the measurement of the intensity of the magnetic field. Moreover, vector measurements make it the only kind of magnetometer allowing compensation of magnetic perturbations due to the equipment carried with it. Unfortunately, Fluxgate magnetometers are quite uncommon in near surface geophysics due to the difficulty to calibrate them precisely. The recent advances in calibration of the sensors and magnetic compensation of the devices from a simple process on the field led Institut de Physique du Globe de Strasbourg to develop instruments for georeferenced magnetic measurements at different scales - from submetric measurements on the ground to aircraft-conducted acquisition through the wide range offered by unmanned aerial vehicles (UAVs) - with a precision in the order of 1 nT. Such equipment is used for different kind of application: structural geology, pipes and UXO detection, archaeology.

European display scene

Science.gov (United States)

Bartlett, Christopher T.

2000-08-01

The manufacture of Flat Panel Displays (FPDs) is dominated by Far Eastern sources, particularly in Active Matrix Liquid Crystal Displays (AMLCD) and Plasma. The United States has a very powerful capability in micro-displays. It is not well known that Europe has a very active research capability which has lead to many innovations in display technology. In addition there is a capability in display manufacturing of organic technologies as well as the licensed build of Japanese or Korean designs. Finally, Europe has a display systems capability in military products which is world class.

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.

Voludensitometry. Three dimensional display of medical objects

International Nuclear Information System (INIS)

Darier, P.; Garderet, P.; Grangeat, P.; Matte, P.; Tournier, E.; Villafana, R.

1984-05-01

In order to study the volumic cartography of material density (X-rays imaging), of proton density (RMN imaging) or of specific activity of a marker (γ or β + imaging) a set of calculation results (called voxels) is reconstructed from sensor data collection. Voxels are identified by a triplet of space coordinates and they represent a local estimation of the parameter to be studied. The concepts for representation there upon developed can be extended for any parameter for which additivity is meaningful. The operator has to govern a software in order to work out the documents leading himself to a mental representation of the object. On a display these documents will be either graphics, images or image sequences. The elementary process for elaboration of one image includes: - conditionning the volume: definition of absolute coordinates (geometrical transformations), interactive extraction (surgery) or automation extraction (segmentation) of sub-volumes, contextual organization (sub-volumes ordering, dissolution); - reduction to two dimensions of the information either by spatial integration (radiography), or by surface representation (morphoscopy). This contribution introduces these different concepts showing the way to the design of an interactive display console. Video recorded sequences that have been realised using an experimental software will illustrate the preliminary results [fr

Identifying performance gaps in hydrogen safety sensor technology for automotive and stationary applications

International Nuclear Information System (INIS)

Boon-Brett, L.; Bousek, J.; Black, G.; Moretto, P.; Castello, P.; Huebert, T.; Banach, U.

2010-01-01

A market survey has been performed of commercially available hydrogen safety sensors, resulting in a total sample size of 53 sensors from 21 manufacturers. The technical specifications, as provided by the manufacturer, have been collated and are displayed herein as a function of sensor working principle. These specifications comprise measuring range, response and recovery times, ambient temperature, pressure and relative humidity, power consumption and lifetime. These are then compared against known performance targets for both automotive and stationary applications in order to establish in how far current technology satisfies current requirements of sensor end users. Gaps in the performance of hydrogen sensing technologies are thus identified and areas recommended for future research and development. (author)

Laser display system for multi-depth screen projection scenarios.

Science.gov (United States)

La Torre, J Pablo; Mayes, Nathan; Riza, Nabeel A

2017-11-10

Proposed is a laser projection display system that uses an electronically controlled variable focus lens (ECVFL) to achieve sharp and in-focus image projection over multi-distance three-dimensional (3D) conformal screens. The system also functions as an embedded distance sensor that enables 3D mapping of the multi-level screen platform before the desired laser scanned beam focused/defocused projected spot sizes are matched to the different localized screen distances on the 3D screen. Compared to conventional laser scanning and spatial light modulator (SLM) based projection systems, the proposed design offers in-focus non-distorted projection over a multi-distance screen zone with varying depths. An experimental projection system for a screen depth variation of 65 cm is demonstrated using a 633 nm laser beam, 3 KHz scan speed galvo-scanning mirrors, and a liquid-based ECVFL. As a basic demonstration, an in-house developed MATLAB based graphic user interface is deployed to work along with the laser projection display, enabling user inputs like text strings or predefined image projection. The user can specify projection screen distance, scanned laser linewidth, projected text font size, projected image dimensions, and laser scanning rate. Projected images are shown highlighting the 3D control capabilities of the display, including the production of a non-distorted image onto two-depths versus a distorted image via dominant prior-art projection methods.

Displays in scintigraphy

International Nuclear Information System (INIS)

Todd-Pokropek, A.E.; Pizer, S.M.

1977-01-01

Displays have several functions: to transmit images, to permit interaction, to quantitate features and to provide records. The main characteristics of displays used for image transmission are their resolution, dynamic range, signal-to-noise ratio and uniformity. Considerations of visual acuity suggest that the display element size should be much less than the data element size, and in current practice at least 256X256 for a gamma camera image. The dynamic range for image transmission should be such that at least 64 levels of grey (or equivalent) are displayed. Scanner displays are also considered, and in particular, the requirements of a whole-body camera are examined. A number of display systems and devices are presented including a 'new' heated object colour display system. Interaction with displays is considered, including background subtraction, contrast enhancement, position indication and region-of-interest generation. Such systems lead to methods of quantitation, which imply knowledge of the expected distributions. Methods for intercomparing displays are considered. Polaroid displays, which have for so long dominated the field, are in the process of being replaced by stored image displays, now that large cheap memories exist which give an equivalent image quality. The impact of this in nuclear medicine is yet to be seen, but a major effect will be to enable true quantitation. (author)

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.

Functionalised zinc oxide nanowire gas sensors: Enhanced NO(2) gas sensor response by chemical modification of nanowire surfaces.

Science.gov (United States)

Waclawik, Eric R; Chang, Jin; Ponzoni, Andrea; Concina, Isabella; Zappa, Dario; Comini, Elisabetta; Motta, Nunzio; Faglia, Guido; Sberveglieri, Giorgio

2012-01-01

Surface coating with an organic self-assembled monolayer (SAM) can enhance surface reactions or the absorption of specific gases and hence improve the response of a metal oxide (MOx) sensor toward particular target gases in the environment. In this study the effect of an adsorbed organic layer on the dynamic response of zinc oxide nanowire gas sensors was investigated. The effect of ZnO surface functionalisation by two different organic molecules, tris(hydroxymethyl)aminomethane (THMA) and dodecanethiol (DT), was studied. The response towards ammonia, nitrous oxide and nitrogen dioxide was investigated for three sensor configurations, namely pure ZnO nanowires, organic-coated ZnO nanowires and ZnO nanowires covered with a sparse layer of organic-coated ZnO nanoparticles. Exposure of the nanowire sensors to the oxidising gas NO(2) produced a significant and reproducible response. ZnO and THMA-coated ZnO nanowire sensors both readily detected NO(2) down to a concentration in the very low ppm range. Notably, the THMA-coated nanowires consistently displayed a small, enhanced response to NO(2) compared to uncoated ZnO nanowire sensors. At the lower concentration levels tested, ZnO nanowire sensors that were coated with THMA-capped ZnO nanoparticles were found to exhibit the greatest enhanced response. ΔR/R was two times greater than that for the as-prepared ZnO nanowire sensors. It is proposed that the ΔR/R enhancement in this case originates from the changes induced in the depletion-layer width of the ZnO nanoparticles that bridge ZnO nanowires resulting from THMA ligand binding to the surface of the particle coating. The heightened response and selectivity to the NO(2) target are positive results arising from the coating of these ZnO nanowire sensors with organic-SAM-functionalised ZnO nanoparticles.

Airborne Laser Polarization Sensor

Science.gov (United States)

Kalshoven, James, Jr.; Dabney, Philip

1991-01-01

Instrument measures polarization characteristics of Earth at three wavelengths. Airborne Laser Polarization Sensor (ALPS) measures optical polarization characteristics of land surface. Designed to be flown at altitudes of approximately 300 m to minimize any polarizing or depolarizing effects of intervening atmosphere and to look along nadir to minimize any effects depending on look angle. Data from measurements used in conjunction with data from ground surveys and aircraft-mounted video recorders to refine mathematical models used in interpretation of higher-altitude polarimetric measurements of reflected sunlight.

Remote Software Application and Display Development

Science.gov (United States)

Sanders, Brandon T.

2014-01-01

The era of the shuttle program has come to an end, but only to give rise to newer and more exciting projects. Now is the time of the Orion spacecraft, a work of art designed to exceed all previous endeavors of man. NASA is exiting the time of exploration and is entering a new period, a period of pioneering. With this new mission, many of NASAs organizations must undergo a great deal of change and development to support the Orion missions. The Spaceport Command and Control System (SCCS) is the new system that will provide NASA the ability to launch rockets into orbit and thus control Orion and other spacecraft as the goal of populating Mars becomes ever increasingly tangible. Since the previous control system, Launch Processing System (LPS), was primarily designed to launch the shuttles, SCCS was needed as Kennedy Space Center (KSC) reorganized to a multiuser spaceport for commercial flights, providing a more versatile control over rockets. Within SCCS, is the Launch Control System (LCS), which is the remote software behind the command and monitoring of flight and ground system hardware. This internship at KSC has involved two main components in LCS, including Remote Software Application and Display development. The display environment provides a graphical user interface for an operator to view and see if any cautions are raised, while the remote applications are the backbone that communicate with hardware, and then relay the data back to the displays. These elements go hand in hand as they provide monitoring and control over hardware and software alike from the safety of the Launch Control Center. The remote software applications are written in Application Control Language (ACL), which must undergo unit testing to ensure data integrity. This paper describes both the implementation and writing of unit tests in ACL code for remote software applications, as well as the building of remote displays to be used in the Launch Control Center (LCC).

Assessing sensor accuracy for non-adjunct use of continuous glucose monitoring.

Science.gov (United States)

Kovatchev, Boris P; Patek, Stephen D; Ortiz, Edward Andrew; Breton, Marc D

2015-03-01

The level of continuous glucose monitoring (CGM) accuracy needed for insulin dosing using sensor values (i.e., the level of accuracy permitting non-adjunct CGM use) is a topic of ongoing debate. Assessment of this level in clinical experiments is virtually impossible because the magnitude of CGM errors cannot be manipulated and related prospectively to clinical outcomes. A combination of archival data (parallel CGM, insulin pump, self-monitoring of blood glucose [SMBG] records, and meals for 56 pump users with type 1 diabetes) and in silico experiments was used to "replay" real-life treatment scenarios and relate sensor error to glycemic outcomes. Nominal blood glucose (BG) traces were extracted using a mathematical model, yielding 2,082 BG segments each initiated by insulin bolus and confirmed by SMBG. These segments were replayed at seven sensor accuracy levels (mean absolute relative differences [MARDs] of 3-22%) testing six scenarios: insulin dosing using sensor values, threshold, and predictive alarms, each without or with considering CGM trend arrows. In all six scenarios, the occurrence of hypoglycemia (frequency of BG levels ≤50 mg/dL and BG levels ≤39 mg/dL) increased with sensor error, displaying an abrupt slope change at MARD =10%. Similarly, hyperglycemia (frequency of BG levels ≥250 mg/dL and BG levels ≥400 mg/dL) increased and displayed an abrupt slope change at MARD=10%. When added to insulin dosing decisions, information from CGM trend arrows, threshold, and predictive alarms resulted in improvement in average glycemia by 1.86, 8.17, and 8.88 mg/dL, respectively. Using CGM for insulin dosing decisions is feasible below a certain level of sensor error, estimated in silico at MARD=10%. In our experiments, further accuracy improvement did not contribute substantively to better glycemic outcomes.

Rapid response sensor to monitor the temperature and flow of liquid metals

International Nuclear Information System (INIS)

McCann, J.D.

1980-01-01

Two forms of a sensor capable of simultaneously monitoring the temperature and flow of liquid metal coolants within a reactor are described. They operate by measuring the coupling impedances between the sensor and the surrounding electrically conductive coolant. Since the system utilises electrical rather than thermal properties, the response to perturbations is rapid, typically displaying the changed conditions within a few milliseconds. The first form of the sensor was designed to operate whilst protected by a thick walled service tube positioned in the reactor coolant. Providing bends in the tube had a radius greater than 70 cm, the sensor could be removed for inspection and maintenance if necessary. The second sensor was fitted inside a streamlined NaK proof capsule. This was inserted directly into the coolant outlet stream of a fuel pin assembly in the Dounreay Fast Reactor. In this form the sensor successfully monitored flow, entrained gas and temperature excursions during the final operating cycle of D.F.R. (author)

Aerial Measuring System Sensor Modeling

International Nuclear Information System (INIS)

Detwiler, R.S.

2002-01-01

This project deals with the modeling the Aerial Measuring System (AMS) fixed-wing and rotary-wing sensor systems, which are critical U.S. Department of Energy's National Nuclear Security Administration (NNSA) Consequence Management assets. The fixed-wing system is critical in detecting lost or stolen radiography or medical sources, or mixed fission products as from a commercial power plant release at high flying altitudes. The helicopter is typically used at lower altitudes to determine ground contamination, such as in measuring americium from a plutonium ground dispersal during a cleanup. Since the sensitivity of these instruments as a function of altitude is crucial in estimating detection limits of various ground contaminations and necessary count times, a characterization of their sensitivity as a function of altitude and energy is needed. Experimental data at altitude as well as laboratory benchmarks is important to insure that the strong effects of air attenuation are modeled correctly. The modeling presented here is the first attempt at such a characterization of the equipment for flying altitudes. The sodium iodide (NaI) sensors utilized with these systems were characterized using the Monte Carlo N-Particle code (MCNP) developed at Los Alamos National Laboratory. For the fixed wing system, calculations modeled the spectral response for the 3-element NaI detector pod and High-Purity Germanium (HPGe) detector, in the relevant energy range of 50 keV to 3 MeV. NaI detector responses were simulated for both point and distributed surface sources as a function of gamma energy and flying altitude. For point sources, photopeak efficiencies were calculated for a zero radial distance and an offset equal to the altitude. For distributed sources approximating an infinite plane, gross count efficiencies were calculated and normalized to a uniform surface deposition of 1 microCi/m 2 . The helicopter calculations modeled the transport of americium-241 ( 241 Am) as this is

Adaptive Multi-Sensor Perception for Driving Automation in Outdoor Contexts

Directory of Open Access Journals (Sweden)

Annalisa Milella

2014-08-01

Full Text Available In this research, adaptive perception for driving automation is discussed so as to enable a vehicle to automatically detect driveable areas and obstacles in the scene. It is especially designed for outdoor contexts where conventional perception systems that rely on a priori knowledge of the terrain's geometric properties, appearance properties, or both, is prone to fail, due to the variability in the terrain properties and environmental conditions. In contrast, the proposed framework uses a self-learning approach to build a model of the ground class that is continuously adjusted online to reflect the latest ground appearance. The system also features high flexibility, as it can work using a single sensor modality or a multi-sensor combination. In the context of this research, different embodiments have been demonstrated using range data coming from either a radar or a stereo camera, and adopting self-supervised strategies where monocular vision is automatically trained by radar or stereo vision. A comprehensive set of experimental results, obtained with different ground vehicles operating in the field, are presented to validate and assess the performance of the system.

Monocular display unit for 3D display with correct depth perception

Science.gov (United States)

Sakamoto, Kunio; Hosomi, Takashi

2009-11-01

A study of virtual-reality system has been popular and its technology has been applied to medical engineering, educational engineering, a CAD/CAM system and so on. The 3D imaging display system has two types in the presentation method; one is a 3-D display system using a special glasses and the other is the monitor system requiring no special glasses. A liquid crystal display (LCD) recently comes into common use. It is possible for this display unit to provide the same size of displaying area as the image screen on the panel. A display system requiring no special glasses is useful for a 3D TV monitor, but this system has demerit such that the size of a monitor restricts the visual field for displaying images. Thus the conventional display can show only one screen, but it is impossible to enlarge the size of a screen, for example twice. To enlarge the display area, the authors have developed an enlarging method of display area using a mirror. Our extension method enables the observers to show the virtual image plane and to enlarge a screen area twice. In the developed display unit, we made use of an image separating technique using polarized glasses, a parallax barrier or a lenticular lens screen for 3D imaging. The mirror can generate the virtual image plane and it enlarges a screen area twice. Meanwhile the 3D display system using special glasses can also display virtual images over a wide area. In this paper, we present a monocular 3D vision system with accommodation mechanism, which is useful function for perceiving depth.

Smart Sensors' Role in Integrated System Health Management

Science.gov (United States)

Perotti, Jose M.; Mata, Carlos

2005-01-01

During the last decade, there has been a major effort in the aerospace industry to reduce the cost per pond of payload and become competitive in the international market. Competition from Europe, Japan, and China has reduced this cost to almost a third from 1990 to 2000. This cost has leveled in recent years to an average price of around $12,000/pound of payload. One of NASA's goals is to promote the development of technologies to reduce this cost by a factor of 10 or more Exploration of space, specially manned exploration missions, involves very complex launch and flight vehicles, associated ground support systems, and extensive human support during all phases of the mission. When considering the Space Shuttle Program, we can see that vehicle and ground support systems' processing, operation, and maintenance represent a large percentage of the program cost and time. Reducing operating, processing and maintenance costs will greatly reduce the cost of Exploration programs. The Integrated System Health Management (ISHM) concept is one of the technologies that will help reduce these operating, processing and maintenance costs. ISHM is an integrated health monitoring system applicable to both flight and ground systems. It automatically and autonomously acquires information from sensors and actuators and processes that information using the ISHM-embedded knowledge. As a result, it establishes the health of the system based on the acquired information and its prior knowledge. When this concept is fully implemented, ISHM systems shall be able to perform failure prediction and remediation before actual hard failures occurs, preventing its costly consequences. Data sources, sensors, and their associated data acquisition systems, constitute the foundation of the system. A smart sensing architecture is required to support the acquisition of reliable, high quality data, required by the ISHM. A thorough definition of the smart sensor architectures, their embedded diagnostic

Conformal flight path symbology for head-up displays: Defining the distribution of visual attention in three-dimensional space

Science.gov (United States)

Ververs, Patricia May

An extensive investigation of the format for head-up display (HUD) instrumentation was conducted in a two-part experiment. First, a pilot's information requirements for the tasks of approach, landing, and taxi were determined through a survey administered to professional commercial pilots via the world wide web. The results of the survey were applied in the development of two symbology sets, one set for flight navigation and the second for ground navigation. Second, twenty pilots from the University of Illinois at Urbana-Champaign were recruited to participate in a 3-day experiment. The study was designed to investigate the format for symbology on HUDs and the performance effects of using conformal and partially conformal symbology to support the pilots' tasks. In addition, two different methods were investigated for supporting the pilots' transition between the task of flying and the task of landing. A seamless transition used visual momentum techniques to smoothly guide the pilots' cognitive transition between the serial displays and the associated tasks. A seamed approach employed an abrupt change between the displays to alert the pilots of the task switch. The results indicate that incorporating a virtually conformal, tunnel-in-the-sky symbology into a complete HUD instrumentation set offers promising pilot performance effects. Pilots easily navigated the complex curved approaches with little to no deviation from the flight path (approximately 10 feet), while performing the secondary tasks of the scanning their instruments and the environment. The seamless transition between the flight and ground symbology offered the pilots a preview of the upcoming landing task, thereby preparing them for the task switch. On the ground, the perspective (scene-linked) symbology set supported landing and taxi navigation tasks with the equal efficiency to the plan view display but with much greater precision. Theories of allocation of attention were used to interpret the

Miniaturized membrane sensors for potentiometric determination of metoprolol tartrate and hydrochlorothiazide.

Science.gov (United States)

Ramadan, Nesrin K; Mohamed, Heba M; Mostafa, Azza A

2012-06-01

Four microsized graphite and platinum wire poly(vinyl chloride) matrix membrane electrodes responsive to some drugs affecting cardiovascular system, Metoprolol tartrate (MT) and Hydrochlorothiazide (HZ) were developed, described and characterized. These sensors were constructed by using (2-Hydroxypropyl)-β-cyclodextrin (2HP β-CD) as an ionophore which has a significant influence on increasing both membrane sensitivity and selectivity. The four sensors were fabricated in a polymeric matrix of carboxylated polyvinyl chloride (PVC-COOH) and dioctylphthalate (DOP) as a plasticizer, based on the interaction between the drugs and the dissociated COOH groups in the PVC-COOH. Fast and stable Nernstian responses of 1.0 × 10-6-1.0 × 10-2 M for MT (sensors 1 and 2) and of 1.0 × 10-7-1.0 × 10-3 M for HZ (sensors 3 and 4) over pH range 3.0-9.0 and 3.0-7.0 for the MT and HZ sensors respectively were obtained. Nernstian slopes of 56.2, 54.6, 19.0 and 20.8 mV/decade for electrodes 1-4 respectively were observed. The proposed method displayed useful analytical characteristics for the determination of MT and HZ in their pure powder forms with average recoveries of 99.11 ± 0.357, 99.21 ± 0.389, 100.08 ± 0.459 and 100.28 ± 0.438% for sensors 1-4 respectively. The lower limit of detection (LOD) were 5.5 × 10-6, 4.5 × 10-6, 4.8 × 10-8 and 5.0 × 10-8 M for sensors 1-4 respectively indicated high sensitivity. The four sensors displayed a good stability over a period of 6 weeks. The selectivity coefficients of the developed sensors indicated excellent selectivity. Results obtained by the four electrodes revealed the performance characteristics of these electrodes which evaluated according to IUPAC recommendations. The method was successively applied for the determination of MT and HZ in presence of each other, in presence of Salamide (SA), the main degradation product of HZ, in their pharmaceutical formulations and in human plasma samples. Statistical comparison between the

A new ground-penetrating radar system for remote site characterization

International Nuclear Information System (INIS)

Davis, K.C.; Sandness, G.A.

1994-08-01

The cleanup of waste burial sites and military bombing ranges involves the risk of exposing field personnel to toxic chemicals, radioactive materials, or unexploded munitions. Time-consuming and costly measures are required to provide protection from those hazards. Therefore, there is a growing interest in developing remotely controlled sensors and sensor platforms that can be employed in site characterization surveys. A specialized ground-penetrating radar has been developed to operate on a remotely controlled vehicle for the non-intrusive subsurface characterization of buried waste sites. Improved radar circuits provide enhanced performance, and an embedded microprocessor dynamically optimizes operation. The radar unit is packaged to survive chemical contamination and decontamination

An experimental investigation on ground heat flow balance issue for a GCHP

OpenAIRE

Jiufa Chen; Hongqi Zheng; Qin Xue; Erming An; Weilai Qiao

2010-01-01

For a ground-coupled heat pump (GCHP), it is vital to keep the ground heat flow balanced in order to achieve sustainable energy-saving operation. However, the importance of this issue has not been well studied. Focused on the heat flow balance issue, this paper made an exclusive experimental study using a newly installed GCHP system with the designed cooling capacity 1960 kW and heating capacity 1590 kW. The GCHP system was equipped with a data acquisition system and had temperature sensors i...

Novel rf power sensor based on capacitive MEMS technology

NARCIS (Netherlands)

Fernandez, L.J.; Visser, Eelke; Sesé, J.; Jansen, Henricus V.; Wiegerink, Remco J.; Flokstra, Jakob

2003-01-01

We present the theory, design, fabrication of and first measurements on a novel power for radio frequency (rf) signals, based on capacitive measurements. The novelty of this sensor is thtat it measures the force that is created between the rf signal and a grounded membrande suspended above the line

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

Electrochemical sensors based on gold nanoparticles modified with rhodamine B hydrazide to sensitively detect Cu(II)

Energy Technology Data Exchange (ETDEWEB)

Peng, Donglai; Hu, Bin; Kang, Mengmeng [Henan Provincial Key Laboratory of Surface and Interface Science, Zhengzhou University of Light Industry, No. 136, Science Avenue, Zhengzhou 450001 (China); Wang, Minghua [Henan Collaborative Innovation Center of Environmental Pollution Control and Ecological Restoration, Zhengzhou University of Light Industry, No.136, Science Avenue, Zhengzhou 450001 (China); He, Linghao [Henan Provincial Key Laboratory of Surface and Interface Science, Zhengzhou University of Light Industry, No. 136, Science Avenue, Zhengzhou 450001 (China); Zhang, Zhihong, E-mail: mainzhh@163.com [Henan Provincial Key Laboratory of Surface and Interface Science, Zhengzhou University of Light Industry, No. 136, Science Avenue, Zhengzhou 450001 (China); Henan Collaborative Innovation Center of Environmental Pollution Control and Ecological Restoration, Zhengzhou University of Light Industry, No.136, Science Avenue, Zhengzhou 450001 (China); Fang, Shaoming, E-mail: mingfang@zzuli.edu.cn [Henan Provincial Key Laboratory of Surface and Interface Science, Zhengzhou University of Light Industry, No. 136, Science Avenue, Zhengzhou 450001 (China); Henan Collaborative Innovation Center of Environmental Pollution Control and Ecological Restoration, Zhengzhou University of Light Industry, No.136, Science Avenue, Zhengzhou 450001 (China)

2016-12-30

Highlights: • An electrochemical sensor based on gold nanoparticles modified with rhodamine B hydrazide (AuNPs-RBH) was developed. • The sensor was applied in the highly sensitive and selective detection of Cu{sup 2+} in water. • The electrochemical sensor displays excellent regeneration, stability, and practicability for Cu{sup 2+} detection. • EIS was used to determine Cu{sup 2+} ions in an aqueous solution with the developed AuNPs-RBH-based electrochemical sensor. - Abstract: An electrochemical sensor based on gold nanoparticles (Au NPs) modified with rhodamine B hydrazide (RBH) (AuNPs-RBH) was developed and applied in the highly sensitive and selective detection of Cu{sup 2+} in water. RBH molecules were bounded onto the surface of AuNPs via the strong interaction between the amino groups and Au NPs. The chemical structure variations were characterized by X-ray photoelectron spectroscopy and fluoresence spectroscopy. Additionally, electrochemical impedance spectroscopy was used to determine Cu{sup 2+} ions in an aqueous solution with the developed AuNPs-RBH-based electrochemical sensor. Results show that the fabricated sensor exhibits good electrochemical performance because of the presence of Au NPs and high affinity with the Cu{sup 2+} resulting from the strong coordination chemistry between Cu{sup 2+} and RBH. The as-developed sensor towards detecting Cu{sup 2+} has a detection limitation of 12.5 fM within the concentration range of 0.1 pM–1 nM by using the electrochemical impedance technique. It also displays excellent selectivity, regeneration, stability, and practicability for Cu{sup 2+} detection. Therefore, the new strategy of the RBH-based electrochemical sensor exhibits great potential application in environment treatment and protection.

ANALYSIS OF SPECTRAL CHARACTERISTICS AMONG DIFFERENT SENSORS BY USE OF SIMULATED RS IMAGES

Institute of Scientific and Technical Information of China (English)

无

2000-01-01

This research, by use of RS image-simulating method, simulated apparent reflectance images at sensor level and ground-reflectance images of SPOT-HRV,CBERS-CCD,Landsat-TM and NOAA14-AVHRR' s corresponding bands. These images were used to analyze sensor's differences caused by spectral sensitivity and atmospheric impacts. The differences were analyzed on Normalized Difference Vegetation Index(NDVI). The results showed that the differences of sensors' spectral characteristics cause changes of their NDVI and reflectance. When multiple sensors' data are applied to digital analysis, the error should be taken into account. Atmospheric effect makes NDVI smaller, and atn~pheric correction has the tendency of increasing NDVI values. The reflectance and their NDVIs of different sensors can be used to analyze the differences among sensor' s features. The spectral analysis method based on RS simulated images can provide a new way to design the spectral characteristics of new sensors.

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

Proteus - A Free and Open Source Sensor Observation Service (SOS) Client

Science.gov (United States)

Henriksson, J.; Satapathy, G.; Bermudez, L. E.

2013-12-01

The Earth's 'electronic skin' is becoming ever more sophisticated with a growing number of sensors measuring everything from seawater salinity levels to atmospheric pressure. To further the scientific application of this data collection effort, it is important to make the data easily available to anyone who wants to use it. Making Earth Science data readily available will allow the data to be used in new and potentially groundbreaking ways. The US National Science and Technology Council made this clear in its most recent National Strategy for Civil Earth Observations report, when it remarked that Earth observations 'are often found to be useful for additional purposes not foreseen during the development of the observation system'. On the road to this goal the Open Geospatial Consortium (OGC) is defining uniform data formats and service interfaces to facilitate the discovery and access of sensor data. This is being done through the Sensor Web Enablement (SWE) stack of standards, which include the Sensor Observation Service (SOS), Sensor Model Language (SensorML), Observations & Measurements (O&M) and Catalog Service for the Web (CSW). End-users do not have to use these standards directly, but can use smart tools that leverage and implement them. We have developed such a tool named Proteus. Proteus is an open-source sensor data discovery client. The goal of Proteus is to be a general-purpose client that can be used by anyone for discovering and accessing sensor data via OGC-based services. Proteus is a desktop client and supports a straightforward workflow for finding sensor data. The workflow takes the user through the process of selecting appropriate services, bounding boxes, observed properties, time periods and other search facets. NASA World Wind is used to display the matching sensor offerings on a map. Data from any sensor offering can be previewed in a time series. The user can download data from a single sensor offering, or download data in bulk from all

Direction Finding Using Multiple MEMS Acoustic Sensors

Science.gov (United States)

2015-09-01

Technologies Boomerang Warrior-X. A shoulder-mounted device detects incoming fire and provides visual and/or audio announcement via speaker , earpiece or...panel, which is located inside the vehicle, alerts soldiers through an LED 12-hour clock image display panel and speaker mounted inside the vehicle...sensor was operated at the bending frequency due to its large amplitude of vibration . Because the bending mode is excited by the pressure gradient of

Sistem Monitoring Parkir Mobil menggunakan Sensor Infrared berbasis RASPBERRY PI

Directory of Open Access Journals (Sweden)

DECY NATALIANA

2016-02-01

Full Text Available ABSTRAK Masalah yang selalu timbul dalam sistem perparkiran adalah kurangnya informasi mengenai status ketersediaan lahan parkir, untuk itu diperlukan sebuah sistem monitoring parkir. Tujuan penelitian ini adalah merancang dan merealisasikan model sistem monitoring perparkiran dengan fasilitas pemilihan area parkir dengan berbasiskan Raspberry Pi serta pemanfaatan infrared sebagai sensor. Sistem ini mampu menampilkan status ketersediaan dari area parkir yang ditampilkan pada display serta dilengkapi dengan perhitungan tarif parkir. Pada sistem yang dirancang dilengkapi dengan tombol untuk memilih area parkir, 2 buah sensor pada masing-masing area parkir untuk mendeteksi kendaraan, kamera untuk kemanan dan lampu LED sebagai indikator ketersediaan area parkir. Perangkat lunak yang digunakan pada sistem ini dirancang dengan menggunakan bahasa Python 2 dan untuk sistem database digunakan SQLite3. Pengujian dilakukan secara simulasi pada miniatur perparkiran. Hasil pengujian model sistem perparkiran dapat menampilkan kondisi dari masing-masing area parkir yang ditampilkan pada display. Kedua buah LED berhasil menjadi indikator ada tidaknya lahan parkir yang masih kosong. Untuk sistem perhitungan tarif parkir telah sesuai dengan perhitungan lamanya parkir. Kata kunci : Parkir, Raspberry Pi , Infrared, Python 2, Monitoring. ABSTRACT The problem which always happens in parking system is the lack of information about the parking area. That’s why we need parking monitoring system. The purposes of this project are to devise and create parking monitoring system which has fitur for ordering parking area. The system based on Raspberry Pi. The system use infra red as sensor. Beside show the availability status of parking area in a display, this system also calculates the price of using the parking area. The System equipped with button for ordering parking area, 2 infrared sensors for each area, web camera for security and 2 LED lamps for availability

Younger and older adults' perception of the Wundt-Hering illusion as a function of display illumination and reflectance contrast.

Science.gov (United States)

Astor-Stetson, E; Lane, S

1991-08-01

Reflectance contrast (i.e., black as compared to grey figures on white ground) and display illumination were manipulated to vary the brightness contrast of Wundt-Hering figures. 16 college students and 16 older adults were presented with high, medium, and low reflectance contrast figures. For half the participants, display illumination was manipulated by covering the figures with a .5 yellow neutral density filter. Magnitude of the illusion increased significantly with increased reflectance contrast for college students, and college students were significantly more susceptible to the high contrast figures than were older adults. Display illumination had no effect on the performance of either group.

Application of electrosynthesized poly(aniline-co-p-aminophenol) as a catechol sensor

International Nuclear Information System (INIS)

Chen Chuanxiang; Sun Cheng; Gao Yuhua

2009-01-01

Poly(aniline-co-p-aminophenol) (copolymer) film was used as a sensor to determine the presence of catechol, taking advantage of the ability of the film to effectively catalyze the oxidation of catechol. The copolymer served as an electron transfer mediator between the electrode surface and catechol in the solution. The response current of the catechol sensor depended on the applied potential, pH and temperature at a given concentration of catechol. At optimum conditions, the catechol sensor displayed an excellent electrocatalytic response to the detection of catechol in a concentration range from 5 to 500 μM with a detection limit of 0.8 μM. The effects of selected organic compounds on the response of the catechol sensor were studied. Together, these findings show that the catechol sensor exhibits a better selectivity towards interfering species and a better operational and storage stability

Development of advanced direct perception displays for nuclear power plants to enhance monitoring, control and fault management

International Nuclear Information System (INIS)

Jones, B.; Shaheen, S.; Moray, N.; Sanderson, P.; Reising, D.V.

1993-01-01

With recent theoretical and empirical research in basic and applied psychology, human factors, and engineering, it is now sufficient to define an integrated approach to the deign of advanced displays for present and future nuclear power plants. Traditionally, the conventional displays have shown operators the individual variables on gauges, meters, strip charts, etc. This design approach requires the operators to mentally integrate the separately displayed variables and determine the implications for the plant state. This traditional approach has been known as the single-sensor-single-indicator display design and it places an intolerable amount of mental workload on operators during transients and abnormal conditions. This report discusses a new alternative approach which is the use of direct perception interfaces. Direct perception a interfaces display the underlying physical and system constraints of the situation in a directly perceptual way, such that the viewer need not reason about what is seen to identify system states, but can identify the state of the system perceptually. It is expected that displays which show the dynamics of fundamental physical laws should better support operator decisions and diagnoses of plant states. The purpose of this research project is to develop a suite of direct perception displays for PWR nuclear power plant operations

Tactile feedback display with spatial and temporal resolutions.

Science.gov (United States)

Vishniakou, Siarhei; Lewis, Brian W; Niu, Xiaofan; Kargar, Alireza; Sun, Ke; Kalajian, Michael; Park, Namseok; Yang, Muchuan; Jing, Yi; Brochu, Paul; Sun, Zhelin; Li, Chun; Nguyen, Truong; Pei, Qibing; Wang, Deli

2013-01-01

We report the electronic recording of the touch contact and pressure using an active matrix pressure sensor array made of transparent zinc oxide thin-film transistors and tactile feedback display using an array of diaphragm actuators made of an interpenetrating polymer elastomer network. Digital replay, editing and manipulation of the recorded touch events were demonstrated with both spatial and temporal resolutions. Analog reproduction of the force is also shown possible using the polymer actuators, despite of the high driving voltage. The ability to record, store, edit, and replay touch information adds an additional dimension to digital technologies and extends the capabilities of modern information exchange with the potential to revolutionize physical learning, social networking, e-commerce, robotics, gaming, medical and military applications.

Tactile Feedback Display with Spatial and Temporal Resolutions

Science.gov (United States)

Vishniakou, Siarhei; Lewis, Brian W.; Niu, Xiaofan; Kargar, Alireza; Sun, Ke; Kalajian, Michael; Park, Namseok; Yang, Muchuan; Jing, Yi; Brochu, Paul; Sun, Zhelin; Li, Chun; Nguyen, Truong; Pei, Qibing; Wang, Deli

2013-08-01

We report the electronic recording of the touch contact and pressure using an active matrix pressure sensor array made of transparent zinc oxide thin-film transistors and tactile feedback display using an array of diaphragm actuators made of an interpenetrating polymer elastomer network. Digital replay, editing and manipulation of the recorded touch events were demonstrated with both spatial and temporal resolutions. Analog reproduction of the force is also shown possible using the polymer actuators, despite of the high driving voltage. The ability to record, store, edit, and replay touch information adds an additional dimension to digital technologies and extends the capabilities of modern information exchange with the potential to revolutionize physical learning, social networking, e-commerce, robotics, gaming, medical and military applications.

Pressure-Sensor Assembly Technique

Science.gov (United States)

Pruzan, Daniel A.

2003-01-01

Nielsen Engineering & Research (NEAR) recently developed an ultrathin data acquisition system for use in turbomachinery testing at NASA Glenn Research Center. This system integrates a microelectromechanical- systems- (MEMS-) based absolute pressure sensor [0 to 50 psia (0 to 345 kPa)], temperature sensor, signal-conditioning application-specific integrated circuit (ASIC), microprocessor, and digital memory into a package which is roughly 2.8 in. (7.1 cm) long by 0.75 in. (1.9 cm) wide. Each of these components is flip-chip attached to a thin, flexible circuit board and subsequently ground and polished to achieve a total system thickness of 0.006 in. (0.15 mm). Because this instrument is so thin, it can be quickly adhered to any surface of interest where data can be collected without disrupting the flow being investigated. One issue in the development of the ultrathin data acquisition system was how to attach the MEMS pressure sensor to the circuit board in a manner which allowed the sensor s diaphragm to communicate with the ambient fluid while providing enough support for the chip to survive the grinding and polishing operations. The technique, developed by NEAR and Jabil Technology Services Group (San Jose, CA), is described below. In the approach developed, the sensor is attached to the specially designed circuit board, see Figure 1, using a modified flip-chip technique. The circular diaphragm on the left side of the sensor is used to actively measure the ambient pressure, while the diaphragm on the right is used to compensate for changes in output due to temperature variations. The circuit board is fabricated with an access hole through it so that when the completed system is installed onto a wind tunnel model (chip side down), the active diaphragm is exposed to the environment. After the sensor is flip-chip attached to the circuit board, the die is underfilled to support the chip during the subsequent grinding and polishing operations. To prevent this

Fabrication and Evaluation of a Graphene Oxide-Based Capacitive Humidity Sensor

Directory of Open Access Journals (Sweden)

Jinfeng Feng

2016-03-01

Full Text Available In this study, a CMOS compatible capacitive humidity sensor structure was designed and fabricated on a 200 mm CMOS BEOL Line. A top Al interconnect layer was used as an electrode with a comb/serpent structure, and graphene oxide (GO was used as sensing material. XRD analysis was done which shows that GO sensing material has a strong and sharp (002 peak at about 10.278°, whereas graphite has (002 peak at about 26°. Device level CV and IV curves were measured in mini-environments at different relative humidity (RH level, and saturated salt solutions were used to build these mini-environments. To evaluate the potential value of GO material in humidity sensor applications, a prototype humidity sensor was designed and fabricated by integrating the sensor with a dedicated readout ASIC and display/calibration module. Measurements in different mini-environments show that the GO-based humidity sensor has higher sensitivity, faster recovery time and good linearity performance. Compared with a standard humidity sensor, the measured RH data of our prototype humidity sensor can match well that of the standard product.

Neuromorphic vision sensors and preprocessors in system applications

Science.gov (United States)

Kramer, Joerg; Indiveri, Giacomo

1998-09-01

A partial review of neuromorphic vision sensors that are suitable for use in autonomous systems is presented. Interfaces are being developed to multiplex the high- dimensional output signals of arrays of such sensors and to communicate them in standard formats to off-chip devices for higher-level processing, actuation, storage and display. Alternatively, on-chip processing stages may be implemented to extract sparse image parameters, thereby obviating the need for multiplexing. Autonomous robots are used to test neuromorphic vision chips in real-world environments and to explore the possibilities of data fusion from different sensing modalities. Examples of autonomous mobile systems that use neuromorphic vision chips for line tracking and optical flow matching are described.

A Vehicle-mounted Crop Detector with Wireless Sensor Network

Directory of Open Access Journals (Sweden)

Zhenjiang ZHONG

2014-03-01

Full Text Available In order to detect crop chlorophyll content in real-time, a new vehicle-mounted detector for measuring crop canopy spectral characteristics was developed. It was designed to work as a wireless sensor network with several optical sensor nodes and one control unit. All the optical sensor nodes were mounted on an on-board mechanical structure so that they could collect the canopy spectral data while in mobile condition. Each optical sensor node was designed to contain four optical channels, which allowed it work at the wavebands of 550, 650, 766 and 850 nm. The control unit included a PDA (Personal Digital Assistant device with a ZigBee wireless network coordinator and a GPRS module. It was used to receive, display, store all the data sent from optical sensor nodes and send data to the server through GPRS module. The calibration tests verified the stability of the wireless network and the measurement precision of the sensors. Both stationary and moving field experiments were also conducted in a winter wheat experimental field. Results showed that the correlation between chlorophyll content and vegetation index had high significance with the highest R2 of 0.6824. Those results showed the potential of the detector for field application.

Perceptual multistability in figure-ground segregation using motion stimuli.

Science.gov (United States)

Gori, Simone; Giora, Enrico; Pedersini, Riccardo

2008-11-01

In a series of experiments using ambiguous stimuli, we investigate the effects of displaying ordered, discrete series of images on the dynamics of figure-ground segregation. For low frame presentation speeds, the series were perceived as a sequence of discontinuous, static images, while for high speeds they were perceived as continuous. We conclude that using stimuli varying continuously along one parameter results in stronger hysteresis and reduces spontaneous switching compared to matched static stimuli with discontinuous parameter changes. The additional evidence that the size of the hysteresis effects depended on trial duration is consistent with the stochastic nature of the dynamics governing figure-ground segregation. The results showed that for continuously changing stimuli, alternative figure-ground organizations are resolved via low-level, dynamical competition. A second series of experiments confirmed these results with an ambiguous stimulus based on Petter's effect.

Can earthquake source inversion benefit from rotational ground motion observations?

Science.gov (United States)

Igel, H.; Donner, S.; Reinwald, M.; Bernauer, M.; Wassermann, J. M.; Fichtner, A.

2015-12-01

With the prospects of instruments to observe rotational ground motions in a wide frequency and amplitude range in the near future we engage in the question how this type of ground motion observation can be used to solve seismic inverse problems. Here, we focus on the question, whether point or finite source inversions can benefit from additional observations of rotational motions. In an attempt to be fair we compare observations from a surface seismic network with N 3-component translational sensors (classic seismometers) with those obtained with N/2 6-component sensors (with additional colocated 3-component rotational motions). Thus we keep the overall number of traces constant. Synthetic seismograms are calculated for known point- or finite-source properties. The corresponding inverse problem is posed in a probabilistic way using the Shannon information content as a measure how the observations constrain the seismic source properties. The results show that with the 6-C subnetworks the source properties are not only equally well recovered (even that would be benefitial because of the substantially reduced logistics installing N/2 sensors) but statistically significant some source properties are almost always better resolved. We assume that this can be attributed to the fact the (in particular vertical) gradient information is contained in the additional rotational motion components. We compare these effects for strike-slip and normal-faulting type sources. Thus the answer to the question raised is a definite "yes". The challenge now is to demonstrate these effects on real data.

Ground Control Point - Wireless System Network for UAV-based environmental monitoring applications

Science.gov (United States)

Mejia-Aguilar, Abraham

2016-04-01

In recent years, Unmanned Aerial Vehicles (UAV) have seen widespread civil applications including usage for survey and monitoring services in areas such as agriculture, construction and civil engineering, private surveillance and reconnaissance services and cultural heritage management. Most aerial monitoring services require the integration of information acquired during the flight (such as imagery) with ground-based information (such as GPS information or others) for improved ground truth validation. For example, to obtain an accurate 3D and Digital Elevation Model based on aerial imagery, it is necessary to include ground-based information of coordinate points, which are normally acquired with surveying methods based on Global Position Systems (GPS). However, GPS surveys are very time consuming and especially for longer time series of monitoring data repeated GPS surveys are necessary. In order to improve speed of data collection and integration, this work presents an autonomous system based on Waspmote technologies build on single nodes interlinked in a Wireless Sensor Network (WSN) star-topology for ground based information collection and later integration with surveying data obtained by UAV. Nodes are designed to be visible from the air, to resist extreme weather conditions with low-power consumption. Besides, nodes are equipped with GPS as well as Inertial Measurement Unit (IMU), accelerometer, temperature and soil moisture sensors and thus provide significant advantages in a broad range of applications for environmental monitoring. For our purpose, the WSN transmits the environmental data with 3G/GPRS to a database on a regular time basis. This project provides a detailed case study and implementation of a Ground Control Point System Network for UAV-based vegetation monitoring of dry mountain grassland in the Matsch valley, Italy.

Invisible Display in Aluminum

DEFF Research Database (Denmark)

Prichystal, Jan Phuklin; Hansen, Hans Nørgaard; Bladt, Henrik Henriksen

2005-01-01

Bang & Olufsen a/s has been working with ideas for invisible integration of displays in metal surfaces. Invisible integration of information displays traditionally has been possible by placing displays behind transparent or semitransparent materials such as plastic or glass. The wish for an integ......Bang & Olufsen a/s has been working with ideas for invisible integration of displays in metal surfaces. Invisible integration of information displays traditionally has been possible by placing displays behind transparent or semitransparent materials such as plastic or glass. The wish...... for an integrated display in a metal surface is often ruled by design and functionality of a product. The integration of displays in metal surfaces requires metal removal in order to clear the area of the display to some extent. The idea behind an invisible display in Aluminum concerns the processing of a metal...

Modern developments for ground-based monitoring of fire behavior and effects

Science.gov (United States)

Colin C. Hardy; Robert Kremens; Matthew B. Dickinson

2010-01-01

Advances in electronic technology over the last several decades have been staggering. The cost of electronics continues to decrease while system performance increases seemingly without limit. We have applied modern techniques in sensors, electronics and instrumentation to create a suite of ground based diagnostics that can be used in laboratory (~ 1 m2), field scale...

Correlator optical wavefront sensor COWS

Science.gov (United States)

1991-02-01

This report documents the significant upgrades and improvements made to the correlator optical wavefront sensor (COWS) optical bench during this phase of the program. Software for the experiment was reviewed and documented. Flowcharts showing the program flow are included as well as documentation for programs which were written to calculate and display Zernike polynomials. The system was calibrated and aligned and a series of experiments to determine the optimum settings for the input and output MOSLM polarizers were conducted. In addition, design of a simple aberration generation is included.

Wireless Sensor Network Handles Image Data

Science.gov (United States)

2008-01-01

To relay data from remote locations for NASA s Earth sciences research, Goddard Space Flight Center contributed to the development of "microservers" (wireless sensor network nodes), which are now used commercially as a quick and affordable means to capture and distribute geographical information, including rich sets of aerial and street-level imagery. NASA began this work out of a necessity for real-time recovery of remote sensor data. These microservers work much like a wireless office network, relaying information between devices. The key difference, however, is that instead of linking workstations within one office, the interconnected microservers operate miles away from one another. This attribute traces back to the technology s original use: The microservers were originally designed for seismology on remote glaciers and ice streams in Alaska, Greenland, and Antarctica-acquiring, storing, and relaying data wirelessly between ground sensors. The microservers boast three key attributes. First, a researcher in the field can establish a "managed network" of microservers and rapidly see the data streams (recovered wirelessly) on a field computer. This rapid feedback permits the researcher to reconfigure the network for different purposes over the course of a field campaign. Second, through careful power management, the microservers can dwell unsupervised in the field for up to 2 years, collecting tremendous amounts of data at a research location. The third attribute is the exciting potential to deploy a microserver network that works in synchrony with robotic explorers (e.g., providing ground truth validation for satellites, supporting rovers as they traverse the local environment). Managed networks of remote microservers that relay data unsupervised for up to 2 years can drastically reduce the costs of field instrumentation and data rec

Phase 1 report on sensor technology, data fusion and data interpretation for site characterization

International Nuclear Information System (INIS)

Beckerman, M.

1991-10-01

In this report we discuss sensor technology, data fusion and data interpretation approaches of possible maximal usefulness for subsurface imaging and characterization of land-fill waste sites. Two sensor technologies, terrain conductivity using electromagnetic induction and ground penetrating radar, are described and the literature on the subject is reviewed. We identify the maximum entropy stochastic method as one providing a rigorously justifiable framework for fusing the sensor data, briefly summarize work done by us in this area, and examine some of the outstanding issues with regard to data fusion and interpretation. 25 refs., 17 figs

Personnel and Vehicle Data Collection at Aberdeen Proving Ground (APG) and its Distribution for Research

Science.gov (United States)

2015-10-01

28 Magnetometer Applied Physics Model 1540-digital 3-axis fluxgate 5 Amplifiers Alligator Technologies USBPGF-S1 programmable instrumentation...Acoustic, Seismic, magnetic, footstep, vehicle, magnetometer , geophone, unattended ground sensor (UGS) 16. SECURITY CLASSIFICATION OF: 17. LIMITATION

Vector-Sensor MUSIC for Polarized Seismic Sources Localization

Directory of Open Access Journals (Sweden)

Jérôme I. Mars

2005-01-01

Full Text Available This paper addresses the problem of high-resolution polarized source detection and introduces a new eigenstructure-based algorithm that yields direction of arrival (DOA and polarization estimates using a vector-sensor (or multicomponent-sensor array. This method is based on separation of the observation space into signal and noise subspaces using fourth-order tensor decomposition. In geophysics, in particular for reservoir acquisition and monitoring, a set of Nx-multicomponent sensors is laid on the ground with constant distance Δx between them. Such a data acquisition scheme has intrinsically three modes: time, distance, and components. The proposed method needs multilinear algebra in order to preserve data structure and avoid reorganization. The data is thus stored in tridimensional arrays rather than matrices. Higher-order eigenvalue decomposition (HOEVD for fourth-order tensors is considered to achieve subspaces estimation and to compute the eigenelements. We propose a tensorial version of the MUSIC algorithm for a vector-sensor array allowing a joint estimation of DOA and signal polarization estimation. Performances of the proposed algorithm are evaluated.

Low Cost and Pipe Conformable Microwave-Based Water-Cut Sensor

KAUST Repository

Karimi, Muhammad Akram

2016-08-11

Efficient oil production and refining processes require the precise measurement of water content in oil. This paper presents a novel planar microwave sensor for entirely non-intrusive in situ water cut (WC) sensing over the full range of operation, i.e., 0%-100%. A planar configuration has enabled the direct implementation of WC sensor on the pipe surface using low cost method, i.e., screen printing using 3D printed mask. Modified ground plane-based T-resonator design makes this WC sensor usable for the wide range of pipe sizes present in the oil industry. The viability of this sensor has been confirmed through electromagnetic simulations as well as through a prototype characterization. Two cases of oil and water mixtures, namely, separate phases and homogeneous mix, have been studied. Measurements performed over two independently built prototypes show the root mean square variation in results of only 0.1%.

Modeling ground vehicle acoustic signatures for analysis and synthesis

International Nuclear Information System (INIS)

Haschke, G.; Stanfield, R.

1995-01-01

Security and weapon systems use acoustic sensor signals to classify and identify moving ground vehicles. Developing robust signal processing algorithms for this is expensive, particularly in presence of acoustic clutter or countermeasures. This paper proposes a parametric ground vehicle acoustic signature model to aid the system designer in understanding which signature features are important, developing corresponding feature extraction algorithms and generating low-cost, high-fidelity synthetic signatures for testing. The authors have proposed computer-generated acoustic signatures of armored, tracked ground vehicles to deceive acoustic-sensored smart munitions. They have developed quantitative measures of how accurately a synthetic acoustic signature matches those produced by actual vehicles. This paper describes parameters of the model used to generate these synthetic signatures and suggests methods for extracting these parameters from signatures of valid vehicle encounters. The model incorporates wide-bandwidth and narrow- bandwidth components that are modulated in a pseudo-random fashion to mimic the time dynamics of valid vehicle signatures. Narrow- bandwidth feature extraction techniques estimate frequency, amplitude and phase information contained in a single set of narrow frequency- band harmonics. Wide-bandwidth feature extraction techniques estimate parameters of a correlated-noise-floor model. Finally, the authors propose a method of modeling the time dynamics of the harmonic amplitudes as a means adding necessary time-varying features to the narrow-bandwidth signal components. The authors present results of applying this modeling technique to acoustic signatures recorded during encounters with one armored, tracked vehicle. Similar modeling techniques can be applied to security systems

White balance tester with color sensor for industrial applications

Science.gov (United States)

Chen, Jiasheng; Zhu, XiaoSong

1996-12-01

The white balance tester is an instrument that adjusts the white balance for color TVs, monitors, and PC displays. We have designed a new white balance tester for use directly at the production line. It picks up the R (Red), G (Green), and B (Blue) signals for the screen using color sensors, compares the signals with the data previously stored in the internal memory, displays their differences with LED bars in the compare mode or displays x y Y, u v Y, JND (just noticeable difference) as well as correlated color temperature in the numerical mode. A built-in TV signal generator sets the luminance of the adjusting screen to the brightness of the reference white screen automatically. A 16-bit single chip microcomputer processes the measured values and controls the output levels of the TV signal generator.

Whole body interaction with public displays

CERN Document Server

Walter, Robert

2017-01-01

This book develops valuable new approaches to digital out-of-home media and digital signage in urban environments. It offers solutions for communicating interactive features of digital signage to passers-by. Digital out-of-home media and digital signage screens are becoming increasingly interactive thanks to touch input technology and gesture recognition. To optimize their conversion rate, interactive public displays must 1) attract attention, 2) communicate to passers-by that they are interactive, 3) explain the interaction, and 4) provide a motivation for passers-by to interact. This book highlights solutions to problems 2 and 3 above. The focus is on whole-body interaction, where the positions and orientations of users and their individual body parts are captured by specialized sensors (e.g., depth cameras). The book presents revealing findings from a field study on communicating interactivity, a laboratory on analysing visual attention, a field study on mid-air gestures, and a field study on using mid-air...

Sensor-Only System Identification for Structural Health Monitoring of Advanced Aircraft

Science.gov (United States)

Kukreja, Sunil L.; Bernstein, Dennis S.

2012-01-01

Environmental conditions, cyclic loading, and aging contribute to structural wear and degradation, and thus potentially catastrophic events. The challenge of health monitoring technology is to determine incipient changes accurately and efficiently. This project addresses this challenge by developing health monitoring techniques that depend only on sensor measurements. Since actively controlled excitation is not needed, sensor-to-sensor identification (S2SID) provides an in-flight diagnostic tool that exploits ambient excitation to provide advance warning of significant changes. S2SID can subsequently be followed up by ground testing to localize and quantify structural changes. The conceptual foundation of S2SID is the notion of a pseudo-transfer function, where one sensor is viewed as the pseudo-input and another is viewed as the pseudo-output, is approach is less restrictive than transmissibility identification and operational modal analysis since no assumption is made about the locations of the sensors relative to the excitation.

Experimental Insights into Ground-State Selection of Quantum XY Pyrochlores

Science.gov (United States)

Hallas, Alannah M.; Gaudet, Jonathan; Gaulin, Bruce D.

2018-03-01

Extensive experimental investigations of the magnetic structures and excitations in the XY pyrochlores have been carried out over the past decade. Three families of XY pyrochlores have emerged: Yb2B2O7, Er2B2O7, and, most recently, [Formula: see text]Co2F7. In each case, the magnetic cation (either Yb, Er, or Co) exhibits XY anisotropy within the local pyrochlore coordinates, a consequence of crystal field effects. Materials in these families display rich phase behavior and are candidates for exotic ground states, such as quantum spin ice, and exotic ground-state selection via order-by-disorder mechanisms. In this review, we present an experimental summary of the ground-state properties of the XY pyrochlores, including evidence that they are strongly influenced by phase competition. We empirically demonstrate the signatures for phase competition in a frustrated magnet: multiple heat capacity anomalies, suppressed TN or TC, sample- and pressure-dependent ground states, and unconventional spin dynamics.

Advanced Colorimetry of Display Systems: Tetra-Chroma3 Display Unit

Directory of Open Access Journals (Sweden)

J. Kaiser

2005-06-01

Full Text Available High-fidelity color image reproduction is one of the key issues invisual telecommunication systems, for electronic commerce,telemedicine, digital museum and so on. All colorimetric standards ofdisplay systems are up to the present day trichromatic. But, from theshape of a horseshoe-area of all existing colors in the CIE xychromaticity diagram it follows that with three real reproductivelights, the stated area in the CIE xy chromaticity diagram cannot beoverlaid. The expansion of the color gamut of a display device ispossible in a few ways. In this paper, the way of increasing the numberof primaries is studied. The fourth cyan primary is added to threeconventional ones to enlarge the color gamut of reproduction towardscyans and yellow-oranges. The original method of color management forthis new display unit is introduced. In addition, the color gamut ofthe designed additive-based display is successfully compared with thecolor gamut of a modern subtractive-based system. A display with morethan three primary colors is called a multiprimary color display. Thevery advantageous property of such display is the possibility todisplay metameric colors.

Applications of FBG sensors on telecom satellites

Science.gov (United States)

Abad, S.; Araújo, F. M.; Ferreira, L. A.; Pedersen, F.; Esteban, M. A.; McKenzie, I.; Karafolas, N.

2017-11-01

Monitoring needs of spacecraft are rapidly increasing due to new and more challenging missions, along with demands to reduce launching costs by minimizing the manufacture, assembly, integration and test time and employing new low weight materials balanced by the need for maximizing system lifetime while maintaining good reliability. Conventional electronic sensors are characterized by their low multiplexing capability and their EMI/RF susceptibility and it is in this scenario that Fiber Optic Sensors (FOS) in general, and more specifically Fiber Bragg Grating (FBG) technology offers important benefits, improving in various ways the already deployed sensing subsystems (e.g. reducing the weight associated with sensor cabling, increasing the number of sensing points) and enabling new monitoring applications that were not possible by using conventional sensing technologies. This work presents the activities performed and the lessons learnt in the frame of ESA's ARTES-5 project "Fiber Optic Sensing Subsystem for Spacecraft Health Monitoring in Telecommunication Satellites". This project finished in July 2009, with the implementation and testing of two different demonstrators employing FBG sensor technology: FBG sensors for temperature monitoring in high voltage environments, and in particular in several parts of electric propulsion subsystems [1], and FBG sensors for thermal monitoring of array-antennas during RF testing [2]. In addition, the contacts performed with different actors within the space community allowed the identification of a special area of interest for the substitution of regular thermocouple instrumentation by FBG technology for thermal vacuum ground testing of satellites.

Air launch wireless sensor nodes (ALSN) for battle damage assessment (BDA)

Science.gov (United States)

Back, Jason M.; Beck, Steven D.; Frank, Mark A.; Hoenes, Eric

2006-05-01

This paper summarizes the Defense Threat Reduction Agency (DTRA) sponsored development and demonstration of an Air Launched Sensor Node (ALSN) system designed to fill DTRA's immediate need to support the Global Strike requirement of weapon-borne deliverable sensors for Battle Damage Assessment (BDA). Unattended ground sensors were integrated into a CBU-103 Tactical Munitions Dispenser (TMD), and flight test demonstrated with the 46 th Test Wing at Eglin AFB, FL. The objectives of the ALSN program were to repackage an existing multi-sensor node system to conform to the payload envelope and deployment configuration design; to integrate this payload into the CBU-103 TMD; and to conduct a combined payload flight test demonstration. The final sensor node included multiple sensors a microphone, a geophone, and multiple directional Passive Infrared (PIR) detectors with processing electronics, a low power wireless communications 802.15.4 mesh network, GPS (Global Positioning System), and power integrated into a form-fit BLU-97 munitions deployable package. This paper will present and discuss the flight test, results, and ALSN performance.

Kelvin probe microscopy and electronic transport measurements in reduced graphene oxide chemical sensors

Science.gov (United States)

Kehayias, Christopher E.; MacNaughton, Samuel; Sonkusale, Sameer; Staii, Cristian

2013-06-01

Reduced graphene oxide (RGO) is an electronically hybrid material that displays remarkable chemical sensing properties. Here, we present a quantitative analysis of the chemical gating effects in RGO-based chemical sensors. The gas sensing devices are patterned in a field-effect transistor geometry, by dielectrophoretic assembly of RGO platelets between gold electrodes deposited on SiO2/Si substrates. We show that these sensors display highly selective and reversible responses to the measured analytes, as well as fast response and recovery times (tens of seconds). We use combined electronic transport/Kelvin probe microscopy measurements to quantify the amount of charge transferred to RGO due to chemical doping when the device is exposed to electron-acceptor (acetone) and electron-donor (ammonia) analytes. We demonstrate that this method allows us to obtain high-resolution maps of the surface potential and local charge distribution both before and after chemical doping, to identify local gate-susceptible areas on the RGO surface, and to directly extract the contact resistance between the RGO and the metallic electrodes. The method presented is general, suggesting that these results have important implications for building graphene and other nanomaterial-based chemical sensors.

Kelvin probe microscopy and electronic transport measurements in reduced graphene oxide chemical sensors.

Science.gov (United States)

Kehayias, Christopher E; MacNaughton, Samuel; Sonkusale, Sameer; Staii, Cristian

2013-06-21

Reduced graphene oxide (RGO) is an electronically hybrid material that displays remarkable chemical sensing properties. Here, we present a quantitative analysis of the chemical gating effects in RGO-based chemical sensors. The gas sensing devices are patterned in a field-effect transistor geometry, by dielectrophoretic assembly of RGO platelets between gold electrodes deposited on SiO2/Si substrates. We show that these sensors display highly selective and reversible responses to the measured analytes, as well as fast response and recovery times (tens of seconds). We use combined electronic transport/Kelvin probe microscopy measurements to quantify the amount of charge transferred to RGO due to chemical doping when the device is exposed to electron-acceptor (acetone) and electron-donor (ammonia) analytes. We demonstrate that this method allows us to obtain high-resolution maps of the surface potential and local charge distribution both before and after chemical doping, to identify local gate-susceptible areas on the RGO surface, and to directly extract the contact resistance between the RGO and the metallic electrodes. The method presented is general, suggesting that these results have important implications for building graphene and other nanomaterial-based chemical sensors.

Perancangan Alat Ukur Kadar Alkohol Menggunakan Sensor Mq-3 Berbasis Mikrokontroler Atmega16

Directory of Open Access Journals (Sweden)

I Gede Surya Merta

2017-09-01

Full Text Available It has been successfully designed an alcohol levels measuring instrument using MQ-3 sensor. The detected alcohol levels processed to be displayed on GUI Visual Basic 6.0 through several circuits, the sensor circuit, the Atmega16 microcontroller minimum system, 5V voltage regulator circuits, CH340 serial communication module and GUI Visual Basic 6.0. The entire circuit is powered by 5VDC regulator circuit. The measurement range of this instrument measures alcohol level in the range 0% to 70%, the levels measured by the instrument will be classified according to the regulations sets by Indonesian government. The instrument works by employing the characteristics of the MQ-3 sensor which has proportional voltage change with alcohol levels that is detected. The Atmega16 circuit is the main unit for data processing, the microcontroller performs the analog to digital data conversion and estimates this digital data into matching alcohol levels. Alcohol content data that processed is displayed on the GUI Visual Basic 6.0 through serial communication module CH340. Detected alcohol levels by this instrument compared with the alcohol levels of sample is match by 99.57%.

Perancangan Alat Ukur Kadar Alkohol Menggunakan Sensor Mq-3 Berbasis Mikrokontroler Atmega16

OpenAIRE

I Gede Surya Merta; I Gusti Agung Widagda; Ida Bagus Alit Paramarta

2017-01-01

It has been successfully designed an alcohol levels measuring instrument using MQ-3 sensor. The detected alcohol levels processed to be displayed on GUI Visual Basic 6.0 through several circuits, the sensor circuit, the Atmega16 microcontroller minimum system, 5V voltage regulator circuits, CH340 serial communication module and GUI Visual Basic 6.0. The entire circuit is powered by 5VDC regulator circuit. The measurement range of this instrument measures alcohol level in the range 0% to 70%, ...

GEARS: An Enterprise Architecture Based On Common Ground Services

Science.gov (United States)

Petersen, S.

2014-12-01

Earth observation satellites collect a broad variety of data used in applications that range from weather forecasting to climate monitoring. Within NOAA the National Environmental Satellite Data and Information Service (NESDIS) supports these applications by operating satellites in both geosynchronous and polar orbits. Traditionally NESDIS has acquired and operated its satellites as stand-alone systems with their own command and control, mission management, processing, and distribution systems. As the volume, velocity, veracity, and variety of sensor data and products produced by these systems continues to increase, NESDIS is migrating to a new concept of operation in which it will operate and sustain the ground infrastructure as an integrated Enterprise. Based on a series of common ground services, the Ground Enterprise Architecture System (GEARS) approach promises greater agility, flexibility, and efficiency at reduced cost. This talk describes the new architecture and associated development activities, and presents the results of initial efforts to improve product processing and distribution.

AWARE: Platform for Autonomous self-deploying and operation of Wireless sensor-actuator networks cooperating with unmanned AeRial vehiclEs

NARCIS (Netherlands)

Ollero, Anibal; Bernard, Markus; La Civita, Marco; van Hoesel, L.F.W.; Marron, Pedro J.; Lepley, Jason; de Andres, Eduardo

This paper presents the AWARE platform that seeks to enable the cooperation of autonomous aerial vehicles with ground wireless sensor-actuator networks comprising both static and mobile nodes carried by vehicles or people. Particularly, the paper presents the middleware, the wireless sensor network,

Firework displays as sources of particles similar to gunshot residue.

Science.gov (United States)

Grima, Matthew; Butler, Mark; Hanson, Robert; Mohameden, Ahmed

2012-03-01

In light of past research being targeted to find specific particles which may be similar to gunshot residue (GSR), this project was formulated to detect any possible particulate by random particle fallout onto substrates at firework displays and to assess the impact this may have on GSR evidence. Firework residue was collected at a display site, from amongst spectators as well as from the author's hair 90min after the display. SEM-EDX analysis has detected such particulate in all three scenarios, with the firework particle population at large providing a solid ground for discrimination from GSR. Wind dispersal was found to decrease the particle population and subsequently, the latter's discriminatory power. Some particles, if treated individually were found to be indistinguishable from GSR. Findings also include residues which may mimic strontium based GSR as well as GSR which may be mixed with that from previous firings. The continuous changes made to primer and propellant compositions by manufacturers also call for greater consideration when classifying particles as originating from pyrotechnic devices. Furthermore, authorities such as police forces should be made more aware about the incidence of such particle transfer in firework related periods. Copyright © 2011 Forensic Science Society. Published by Elsevier Ireland Ltd. All rights reserved.

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.

Circuit Design for Sensor Detection Signal Conditioner Nitrate Content

Directory of Open Access Journals (Sweden)

Robeth Manurung

2011-09-01

Full Text Available Nitrate is one of macro nutrients very important for agriculture. The availability of nitrate in soil is limited because it is very easy to leaching by rain, therefore nitrate could be contaminated ground water by  over-process of fertilizer. This process could also produce inefficiency in agriculture if it happened continuesly without pre-analysis of farm field. The answer those problems, it is need to develop the ion sensor system to measure concentrations of nitrat in soil. The system is consist of nitrate ion sensor device, signal conditioning and data acquisition circuit. The design and fabrications of signal conditioning circuit which integrated into ion nitrate sensor system and will apply for agriculture. This sensor has been used amperometric with three electrodes configuration: working, reference  and auxiliarry; the ion senstive membrane has use conductive polymer. The screen printing technique has been choosen to fabricate electrodes and deposition technique for ion sensitive membrane is electropolymerization. The characterization of sensor has been conducted using nitrate standard solution with range of concentration between 1 µM–1 mM. The characterization has shown that sensor has a good response with cureent output between 2.8–4.71 µA, liniearity factor is 99.65% and time response 250 second.

The Effect of a Monocular Helmet-Mounted Display on Aircrew Health: A Longitudinal Cohort Study of Apache AH Mk 1 Pilots -(Vision and Handedness)

Science.gov (United States)

2015-05-19

the day, night, and in adverse weather through the use of nose-mounted, forward-looking infrared (FLIR) pilotage and targeting sensors that provide a...sensor video and/or symbology to each crewmember via a helmet display unit (HDU). The HDU contains a 1-inch (in.) diameter cathode ray tube (CRT...American Association for Pediatric Ophthalmology and Strabismus, 12(4): 365–369. Sale, D. F., and Lund, G. J. 1993. AH-64 Apache program update

A novel low-power fluxgate sensor using a macroscale optimisation technique for space physics instrumentation

Science.gov (United States)

Dekoulis, G.; Honary, F.

2007-05-01

This paper describes the design of a novel low-power single-axis fluxgate sensor. Several soft magnetic alloy materials have been considered and the choice was based on the balance between maximum permeability and minimum saturation flux density values. The sensor has been modelled using the Finite Integration Theory (FIT) method. The sensor was imposed to a custom macroscale optimisation technique that significantly reduced the power consumption by a factor of 16. The results of the sensor's optimisation technique will be used, subsequently, in the development of a cutting-edge ground based magnetometer for the study of the complex solar wind-magnetospheric-ionospheric system.

Boronic acid based imprinted electrochemical sensor for rutin recognition and detection.

Science.gov (United States)

Wang, Chunlei; Wang, Qi; Zhong, Min; Kan, Xianwen

2016-10-21

Multi-walled carbon nanotubes (MWNTs) and boronic acid based molecular imprinting polymer (MIP) were successively modified on a glassy carbon electrode surface to fabricate a novel electrochemical sensor for rutin recognition and detection. 3-Aminophenylboronic acid (APBA) was chosen as a monomer for the electropolymerization of MIP film in the presence of rutin. In addition to the imprinted cavities in MIP film to complement the template molecule in shape and functional groups, the high affinity between the boronic acid group of APBA and vicinal diols of rutin also enhanced the selectivity of the sensor, which made the sensor display a good selectivity to rutin. Moreover, the modified MWNTs improved the sensitivity of the sensor for rutin detection. The mole ratios of rutin and APBA, electropolymerized scan cycles and rates, and pH value of the detection solution were optimized. Under optimal conditions, the sensor was used to detect rutin in a linear range from 4.0 × 10 -7 to 1.0 × 10 -5 mol L -1 with a detection limit of 1.1 × 10 -7 mol L -1 . The sensor has also been applied to assay rutin in tablets with satisfactory results.

Production Rule Systems as an Approach to Interpretation of Ground Sensor Information.

Science.gov (United States)

1980-06-01

Z_4 1. Overview . . .......... . .. 4 2. tesin of the Prototype Knowledee -based "?roluc tior System ..................... 4 I V ’?>NA...operated by the sensor control and management platoon (SCAMP). One SCAMP is allocated per division; each SCAMP functions under the coRnizance of the 414...apprnach. Sienal understandin- tasks, of which the problem under consideration in this thesis is a member, seem well suited to the application of knowlede

Underwater detection by using ultrasonic sensor

Science.gov (United States)

Bakar, S. A. A.; Ong, N. R.; Aziz, M. H. A.; Alcain, J. B.; Haimi, W. M. W. N.; Sauli, Z.

2017-09-01

This paper described the low cost implementation of hardware and software in developing the system of ultrasonic which can visualize the feedback of sound in the form of measured distance through mobile phone and monitoring the frequency of detection by using real time graph of Java application. A single waterproof transducer of JSN-SR04T had been used to determine the distance of an object based on operation of the classic pulse echo detection method underwater. In this experiment, the system was tested by placing the housing which consisted of Arduino UNO, Bluetooth module of HC-06, ultrasonic sensor and LEDs at the top of the box and the transducer was immersed in the water. The system which had been tested for detection in vertical form was found to be capable of reporting through the use of colored LEDs as indicator to the relative proximity of object distance underwater form the sensor. As a conclusion, the system can detect the presence of an object underwater within the range of ultrasonic sensor and display the measured distance onto the mobile phone and the real time graph had been successfully generated.

A novel chalcone-analogue as an optical sensor based on ground and excited states intramolecular charge transfer: A combined experimental and theoretical study

International Nuclear Information System (INIS)

Fayed, Tarek A.

2006-01-01

Steady-state absorption and emission spectroscopic techniques as well as semiempirical quantum calculations at the AM1 and ZINDO/S levels have been used to investigate the intramolecular charge transfer (ICT) behaviour of a novel chalcone namely; 1-(2-pyridyl)-5-(4-dimethylaminophenyl)-penta-2,4-diene-1-one, DMAC. The ground state DMAC has a significant ICT character and a great sensitivity to the hydrogen bond donating ability of the medium as reflected from the change of the absorption spectra in pure and mixed organic solvents. On the other hand, its excited singlet state exhibits high ICT characters as manifested by the drastic solvatochromic effects. These results are consistent with the data of charge density calculations in both the ground and excited state, which indicates enhancement of the charge transfer from the dimethyl-amino group to the carbonyl oxygen upon excitation. Also, the dipole moment calculations indicates a highly dipolar excited singlet state (Δμ eg = 15.5 D). The solvent dependence of the fluorescence quantum yield of DMAC was interpreted on the basis of positive and negative solvatokinetic as well as the hydrogen bonding effects. Incorporation of the 2-pyridyl group in the chemical structure of the present DMAC led to design of a potential optical sensor for probing acidity of the medium and metal cations such as Zn 2+ , Cd 2+ and Hg 2+ . This was concluded from the high acidochromic and metallochromic behaviour of DMAC on adding such cations to its acetonitrile solutions

A multi-sensor study of the impact of ground-based glaciogenic seeding on orogrpahic clouds and precipitation

Science.gov (United States)

Pokharel, Binod

in individual WCR reflectivity transects downwind of the silver iodide (AgI) generators, and that the natural trends in the precipitation over short timescales can easily overwhelm any seeding-induced change. Therefore the ASCII experimental design included a control region, upwind of the AgI generators. The three case studies generally show an increase in surface snow particle concentration in the target region during the seeding period. Frequency-by-altitude displays of all WCR reflectivity data collected during the flights show slightly higher reflectivity values during seeding near the ground, at least when compared to the control region, in all three cases. This also applies to the two other radar systems (MRR and DOW), both with their own sampling strategy and target/control regions. An examination of all ASCII cases combined (the "composite" analysis) also shows a positive trend in low-level reflectivity relative to the control region, both in convective and in stratiform cases. Also, convective cells sampled at flight level downwind of the AgI generators contain a higher concentration of small ice crystals during seeding. A word of caution is warranted: both the magnitude and the sign of the change in the target region, compared to that in the control region, varies from case to case in the composite, and amongst the three radar systems (WCR, DOW and MRR). We speculate that this variation is only partly driven by different responses of orographic clouds to glaciogenic seeding, related to factors such as cloud base and cloud top temperature, cloud liquid water content, and snow growth mechanism. Instead, most of this variation probably relates to non-homogenous natural trends across the mountain range, and/or to sample unrepresentativeness, especially for the (relative small) control region, in other words to the sampling methods. The impact of natural variability and sampling aliasing can only be overcome by a storm sample size much larger than that collected

Online vehicle and atmospheric pollution monitoring using GIS and wireless sensor networks

International Nuclear Information System (INIS)

Cordova-Lopez, L E; Mason, A; Cullen, J D; Shaw, A; Al-Shamma'a, A I

2007-01-01

A Geographical Information System (GIS) is a computer system designed to integrate, store, edit, analyse, share and display geographically referenced data. A wireless sensor network (WSN) is a wireless network of spatially distributed autonomous devices using sensors to monitor physical or environmental conditions. This paper presents the integration of these two technologies to create a system able to detect measure and transmit information regarding the presence and quantities of internal combustion derived pollution and the geographical location in real time with the aim of creating pollution maps in urban environments

A radar-enabled collaborative sensor network integrating COTS technology for surveillance and tracking.

Science.gov (United States)

Kozma, Robert; Wang, Lan; Iftekharuddin, Khan; McCracken, Ernest; Khan, Muhammad; Islam, Khandakar; Bhurtel, Sushil R; Demirer, R Murat

2012-01-01

The feasibility of using Commercial Off-The-Shelf (COTS) sensor nodes is studied in a distributed network, aiming at dynamic surveillance and tracking of ground targets. Data acquisition by low-cost (wireless mote is described. We demonstrate the detection, ranging and velocity estimation, classification and tracking capabilities of the mini-radar, and compare results to simulations and manual measurements. Furthermore, we supplement the radar output with other sensor modalities, such as acoustic and vibration sensors. This method provides innovative solutions for detecting, identifying, and tracking vehicles and dismounts over a wide area in noisy conditions. This study presents a step towards distributed intelligent decision support and demonstrates effectiveness of small cheap sensors, which can complement advanced technologies in certain real-life scenarios.

Impact of Soil Water Content on Landmine Detection Using Radar and Thermal Infrared Sensors

National Research Council Canada - National Science Library

Hong, Sung-ho

2001-01-01

.... The most important of these is water content since it directly influences the three other properties in this study, the ground penetrating radar and thermal infrared sensors were used to identify non...

Sensor equipment of the German earth scientific airplane program

Science.gov (United States)

Seige, P.

1975-01-01

The German airplane program for earth scientific research supports the work of a vast staff of earth scientists from universities and federal agencies. Due to their fields of interest, which are in oceanography, hydrology, geology, ecology, and forestry, five test areas were selected which are spread all over Germany. The sensor package, which was designed in accordance with the requirements of this group of scientists, will be installed in a DO 28 D2 type airplane. The sensor equipment consists of a series of 70-mm cameras having different film/filter combinations, a photogrammetric camera, an infrared radiometer, an 11-channel multispectral line scanner, a LANDSAT-compatible radiometer, and a complex avionic system. Along with the airplane, a truck will be equipped with a set of radiometers and other sensor devices for extensive ground-truth measurement; this also includes a cherry picker.

Algorithms exploiting ultrasonic sensors for subject classification

Science.gov (United States)

Desai, Sachi; Quoraishee, Shafik

2009-09-01

Proposed here is a series of techniques exploiting micro-Doppler ultrasonic sensors capable of characterizing various detected mammalian targets based on their physiological movements captured a series of robust features. Employed is a combination of unique and conventional digital signal processing techniques arranged in such a manner they become capable of classifying a series of walkers. These processes for feature extraction develops a robust feature space capable of providing discrimination of various movements generated from bipeds and quadrupeds and further subdivided into large or small. These movements can be exploited to provide specific information of a given signature dividing it in a series of subset signatures exploiting wavelets to generate start/stop times. After viewing a series spectrograms of the signature we are able to see distinct differences and utilizing kurtosis, we generate an envelope detector capable of isolating each of the corresponding step cycles generated during a walk. The walk cycle is defined as one complete sequence of walking/running from the foot pushing off the ground and concluding when returning to the ground. This time information segments the events that are readily seen in the spectrogram but obstructed in the temporal domain into individual walk sequences. This walking sequence is then subsequently translated into a three dimensional waterfall plot defining the expected energy value associated with the motion at particular instance of time and frequency. The value is capable of being repeatable for each particular class and employable to discriminate the events. Highly reliable classification is realized exploiting a classifier trained on a candidate sample space derived from the associated gyrations created by motion from actors of interest. The classifier developed herein provides a capability to classify events as an adult humans, children humans, horses, and dogs at potentially high rates based on the tested sample

Handbook of display technology

CERN Document Server

Castellano, Joseph A

1992-01-01

This book presents a comprehensive review of technical and commercial aspects of display technology. It provides design engineers with the information needed to select proper technology for new products. The book focuses on flat, thin displays such as light-emitting diodes, plasma display panels, and liquid crystal displays, but it also includes material on cathode ray tubes. Displays include a large number of products from televisions, auto dashboards, radios, and household appliances, to gasoline pumps, heart monitors, microwave ovens, and more.For more information on display tech

Ground Operations Autonomous Control and Integrated Health Management

Science.gov (United States)

Daniels, James

2014-01-01

The Ground Operations Autonomous Control and Integrated Health Management plays a key role for future ground operations at NASA. The software that is integrated into this system is called G2 2011 Gensym. The purpose of this report is to describe the Ground Operations Autonomous Control and Integrated Health Management with the use of the G2 Gensym software and the G2 NASA toolkit for Integrated System Health Management (ISHM) which is a Computer Software Configuration Item (CSCI). The decision rationale for the use of the G2 platform is to develop a modular capability for ISHM and AC. Toolkit modules include knowledge bases that are generic and can be applied in any application domain module. That way, there's a maximization of reusability, maintainability, and systematic evolution, portability, and scalability. Engine modules are generic, while application modules represent the domain model of a specific application. Furthermore, the NASA toolkit, developed since 2006 (a set of modules), makes it possible to create application domain models quickly, using pre-defined objects that include sensors and components libraries for typical fluid, electrical, and mechanical systems.

Sensor Fusion Based Model for Collision Free Mobile Robot Navigation

Science.gov (United States)

Almasri, Marwah; Elleithy, Khaled; Alajlan, Abrar

2015-01-01

Autonomous mobile robots have become a very popular and interesting topic in the last decade. Each of them are equipped with various types of sensors such as GPS, camera, infrared and ultrasonic sensors. These sensors are used to observe the surrounding environment. However, these sensors sometimes fail and have inaccurate readings. Therefore, the integration of sensor fusion will help to solve this dilemma and enhance the overall performance. This paper presents a collision free mobile robot navigation based on the fuzzy logic fusion model. Eight distance sensors and a range finder camera are used for the collision avoidance approach where three ground sensors are used for the line or path following approach. The fuzzy system is composed of nine inputs which are the eight distance sensors and the camera, two outputs which are the left and right velocities of the mobile robot’s wheels, and 24 fuzzy rules for the robot’s movement. Webots Pro simulator is used for modeling the environment and the robot. The proposed methodology, which includes the collision avoidance based on fuzzy logic fusion model and line following robot, has been implemented and tested through simulation and real time experiments. Various scenarios have been presented with static and dynamic obstacles using one robot and two robots while avoiding obstacles in different shapes and sizes. PMID:26712766

Sensor Fusion Based Model for Collision Free Mobile Robot Navigation

Directory of Open Access Journals (Sweden)

Marwah Almasri

2015-12-01

Full Text Available Autonomous mobile robots have become a very popular and interesting topic in the last decade. Each of them are equipped with various types of sensors such as GPS, camera, infrared and ultrasonic sensors. These sensors are used to observe the surrounding environment. However, these sensors sometimes fail and have inaccurate readings. Therefore, the integration of sensor fusion will help to solve this dilemma and enhance the overall performance. This paper presents a collision free mobile robot navigation based on the fuzzy logic fusion model. Eight distance sensors and a range finder camera are used for the collision avoidance approach where three ground sensors are used for the line or path following approach. The fuzzy system is composed of nine inputs which are the eight distance sensors and the camera, two outputs which are the left and right velocities of the mobile robot’s wheels, and 24 fuzzy rules for the robot’s movement. Webots Pro simulator is used for modeling the environment and the robot. The proposed methodology, which includes the collision avoidance based on fuzzy logic fusion model and line following robot, has been implemented and tested through simulation and real time experiments. Various scenarios have been presented with static and dynamic obstacles using one robot and two robots while avoiding obstacles in different shapes and sizes.

Opto-mechanical lab-on-fibre seismic sensors detected the Norcia earthquake.

Science.gov (United States)

Pisco, Marco; Bruno, Francesco Antonio; Galluzzo, Danilo; Nardone, Lucia; Gruca, Grzegorz; Rijnveld, Niek; Bianco, Francesca; Cutolo, Antonello; Cusano, Andrea

2018-04-27

We have designed and developed lab-on-fibre seismic sensors containing a micro-opto-mechanical cavity on the fibre tip. The mechanical cavity is designed as a double cantilever suspended on the fibre end facet and connected to a proof mass to tune its response. Ground acceleration leads to displacement of the cavity length, which in turn can be remotely detected using an interferometric interrogation technique. After the sensors characterization, an experimental validation was conducted at the Italian National Institute of Geophysics and Volcanology (INGV), which is responsible for seismic surveillance over the Italian country. The fabricated sensors have been continuously used for long periods to demonstrate their effectiveness as seismic accelerometer sensors. During the tests, fibre optic seismic accelerometers clearly detected the seismic sequence that culminated in the severe Mw6.5 Norcia earthquake that struck central Italy on October 30, 2016. The seismic data provided by the optical sensors were analysed by specialists at the INGV. The wave traces were compared with state-of-the-art traditional sensors typically incorporated into the INGV seismic networks. The comparison verifies the high fidelity of the optical sensors in seismic wave detection, indicating their suitability for a novel class of seismic sensors to be employed in practical scenarios.

Sense, decide, act, communicate (SDAC): next generation of smart sensor systems

Science.gov (United States)

Berry, Nina; Davis, Jesse; Ko, Teresa H.; Kyker, Ron; Pate, Ron; Stark, Doug; Stinnett, Regan; Baker, James; Cushner, Adam; Van Dyke, Colin; Kyckelhahn, Brian

2004-09-01

The recent war on terrorism and increased urban warfare has been a major catalysis for increased interest in the development of disposable unattended wireless ground sensors. While the application of these sensors to hostile domains has been generally governed by specific tasks, this research explores a unique paradigm capitalizing on the fundamental functionality related to sensor systems. This functionality includes a sensors ability to Sense - multi-modal sensing of environmental events, Decide - smart analysis of sensor data, Act - response to environmental events, and Communication - internal to system and external to humans (SDAC). The main concept behind SDAC sensor systems is to integrate the hardware, software, and networking to generate 'knowledge and not just data'. This research explores the usage of wireless SDAC units to collectively make up a sensor system capable of persistent, adaptive, and autonomous behavior. These systems are base on the evaluation of scenarios and existing systems covering various domains. This paper presents a promising view of sensor network characteristics, which will eventually yield smart (intelligent collectives) network arrays of SDAC sensing units generally applicable to multiple related domains. This paper will also discuss and evaluate the demonstration system developed to test the concepts related to SDAC systems.

Design and Fabrication of Vertically-Integrated CMOS Image Sensors

Science.gov (United States)

Skorka, Orit; Joseph, Dileepan

2011-01-01

Technologies to fabricate integrated circuits (IC) with 3D structures are an emerging trend in IC design. They are based on vertical stacking of active components to form heterogeneous microsystems. Electronic image sensors will benefit from these technologies because they allow increased pixel-level data processing and device optimization. This paper covers general principles in the design of vertically-integrated (VI) CMOS image sensors that are fabricated by flip-chip bonding. These sensors are composed of a CMOS die and a photodetector die. As a specific example, the paper presents a VI-CMOS image sensor that was designed at the University of Alberta, and fabricated with the help of CMC Microsystems and Micralyne Inc. To realize prototypes, CMOS dies with logarithmic active pixels were prepared in a commercial process, and photodetector dies with metal-semiconductor-metal devices were prepared in a custom process using hydrogenated amorphous silicon. The paper also describes a digital camera that was developed to test the prototype. In this camera, scenes captured by the image sensor are read using an FPGA board, and sent in real time to a PC over USB for data processing and display. Experimental results show that the VI-CMOS prototype has a higher dynamic range and a lower dark limit than conventional electronic image sensors. PMID:22163860

Figure and ground in the visual cortex: v2 combines stereoscopic cues with gestalt rules.

Science.gov (United States)

Qiu, Fangtu T; von der Heydt, Rüdiger

2005-07-07

Figure-ground organization is a process by which the visual system identifies some image regions as foreground and others as background, inferring 3D layout from 2D displays. A recent study reported that edge responses of neurons in area V2 are selective for side-of-figure, suggesting that figure-ground organization is encoded in the contour signals (border ownership coding). Here, we show that area V2 combines two strategies of computation, one that exploits binocular stereoscopic information for the definition of local depth order, and another that exploits the global configuration of contours (Gestalt factors). These are combined in single neurons so that the "near" side of the preferred 3D edge generally coincides with the preferred side-of-figure in 2D displays. Thus, area V2 represents the borders of 2D figures as edges of surfaces, as if the figures were objects in 3D space. Even in 3D displays, Gestalt factors influence the responses and can enhance or null the stereoscopic depth information.

Liquid crystal display

International Nuclear Information System (INIS)

Takami, K.

1981-01-01

An improved liquid crystal display device is described which can display letters, numerals and other necessary patterns in the night time using a minimized amount of radioactive material. To achieve this a self-luminous light source is placed in a limited region corresponding to a specific display area. (U.K.)

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

Adding Theoretical Grounding to Grounded Theory: Toward Multi-Grounded Theory

OpenAIRE

Göran Goldkuhl; Stefan Cronholm

2010-01-01

The purpose of this paper is to challenge some of the cornerstones of the grounded theory approach and propose an extended and alternative approach for data analysis and theory development, which the authors call multi-grounded theory (MGT). A multi-grounded theory is not only empirically grounded; it is also grounded in other ways. Three different grounding processes are acknowledged: theoretical, empirical, and internal grounding. The authors go beyond the pure inductivist approach in GT an...

Strategy of thunderstorm measurement with super dense ground-based observation network

Science.gov (United States)

Takahashi, Y.; Sato, M.

2014-12-01

It's not easy to understand the inside structure and developing process of thunderstorm only with existing meteorological instruments since its horizontal extent of the storm cell is sometimes smaller than an order of 10 km while one of the densest ground network in Japan, AMEDAS, consists of sites located every 17 km in average and the resolution of meteorological radar is 1-2 km in general. Even the X-band radar realizes the resolution of 250 m or larger. Here we suggest a new super dense observation network with simple and low cost sensors that can be used for measurement both of raindrop and vertical electric field change caused by cloud-to-ground lightning discharge. This sensor consists of two aluminum plates with a diameter of 10-20 cm. We carried out an observation campaign in summer of 2013 in the foothills of Mt. Yastugatake, Yamanashi and Nagano prefectures in Japan, installing 6 plate-type sensors at a distance of about 4 km. Horizontal location, height and charge amount of each lightning discharge are estimated successfully based on the information of electric field changes at several observing sites. Moreover, it was found that the thunderstorm has a very narrow structure well smaller than 300 m that cannot be measured by any other ways, counting the positive and negative pulses caused by attachment of raindrop to the sensor plate, respectively. We plan to construct a new super dense observation network in the north Kanto region, Japan, where the lightning activity is most prominent in summer Japan, distributing more than several tens of sensors at every 4 km or shorter, such as an order of 100 m at minimum. This kind of new type network will reveal the unknown fine structures of thunderstorms and open the door for constructing real time alert system of torrential rainfall and lightning stroke especially in the city area.

A hand-held sensor for analyses of local distributions of magnetic fields and losses

CERN Document Server

Krismanic, G; Baumgartinger, N

2000-01-01

The paper describes a novel sensor for non-destructive analyses of local field and loss distributions in laminated soft magnetic cores, such as transformer cores. It was designed for rapid information on comparative local degrees of inhomogeneity, e.g., for the estimation of local building factors. Similar to a magnifying glass with handle, the compact hand-held sensor contains extremely sharp needle electrodes for the detection of the induction vector B as well as double-field coils for the vector H. Losses P are derived from the Poynting law. Applied to inner -- or also outer -- core regions, the sensor yields instantaneous computer displays of local H, B, and P.

Portable equipment for determining ripeness in Hass avocado using a low cost color sensor

Science.gov (United States)

Toro, Jessica; Daza, Carolina; Vega, Fabio; Diaz, Leonardo; Torres, Cesar

2015-08-01

The avocado is a one climacteric fruit that not ripe on the tree because it produces a maturation inhibitor that passes the fruit through the pedicel, the ripening occurs naturally during storage or to be induced as required. In post-harvest ripening stage is basically determined by experience of the farmer or buyer. In this word us developed portable equipment for determining ripeness is hass avocado using a low cost sensor color sensor TC3200 and LCD for display result. The prototype read of RGB color frequencies of the sensor and estimates the stage of ripeness in fourth different stages in post-harvest ripening.

A Vision for an International Multi-Sensor Snow Observing Mission

Science.gov (United States)

Kim, Edward

2015-01-01

Discussions within the international snow remote sensing community over the past two years have led to encouraging consensus regarding the broad outlines of a dedicated snow observing mission. The primary consensus - that since no single sensor type is satisfactory across all snow types and across all confounding factors, a multi-sensor approach is required - naturally leads to questions about the exact mix of sensors, required accuracies, and so on. In short, the natural next step is to collect such multi-sensor snow observations (with detailed ground truth) to enable trade studies of various possible mission concepts. Such trade studies must assess the strengths and limitations of heritage as well as newer measurement techniques with an eye toward natural sensitivity to desired parameters such as snow depth and/or snow water equivalent (SWE) in spite of confounding factors like clouds, lack of solar illumination, forest cover, and topography, measurement accuracy, temporal and spatial coverage, technological maturity, and cost.

Acoustic-Seismic Coupling in Porous Ground - Measurements and Analysis for On-Site-Inspection Support

Science.gov (United States)

Liebsch, Mattes; Gorschlüter, Felix; Altmann, Jürgen

2014-05-01

During on-site inspections (OSI) of the Comprehensive Nuclear Test Ban Treaty Organisation (CTBTO) a local seismic network can be installed to measure seismic aftershock signals of an assumed underground nuclear explosion. These signals are caused by relaxation processes in and near the cavity created by the explosion and when detected can lead to a localisation of the cavity. This localisation is necessary to take gas samples from the ground which are analysed for radioactive noble gas isotopes to confirm or dismiss the suspicion of a nuclear test. The aftershock signals are of very low magnitude so they can be masked by different sources, in particular periodic disturbances caused by vehicles and aircraft in the inspection area. Vehicles and aircraft (mainly helicopters) will be used for the inspection activities themselves, e.g. for overhead imagery or magnetic-anomaly sensing. While vehicles in contact with the ground can excite soil vibrations directly, aircraft and vehicles alike emit acoustic waves which excite soil vibrations when hitting the ground. These disturbing signals are of periodic nature while the seismic aftershock signals are pulse-shaped, so their separation is possible. The understanding of the coupling of acoustic waves to the ground is yet incomplete, a better understanding is necessary to improve the performance of an OSI, e.g. to address potential consequences for the sensor placement, the helicopter trajectories etc. In a project funded by the Young Scientist Research Award of the CTBTO to one of us (ML), we investigated the acoustic-seismic coupling of airborne signals of jet aircraft and artificially induced ones by a speaker. During a measurement campaign several acoustic and seismic sensors were placed below the take-off trajectory of an airport at 4 km distance. Therefore taking off and landing jet aircraft passed nearly straightly above the setup. Microphones were placed close to the ground to record the sound pressure of incident

Markerless Augmented Reality via Stereo Video See-Through Head-Mounted Display Device

Directory of Open Access Journals (Sweden)

Chung-Hung Hsieh

2015-01-01

Full Text Available Conventionally, the camera localization for augmented reality (AR relies on detecting a known pattern within the captured images. In this study, a markerless AR scheme has been designed based on a Stereo Video See-Through Head-Mounted Display (HMD device. The proposed markerless AR scheme can be utilized for medical applications such as training, telementoring, or preoperative explanation. Firstly, a virtual model for AR visualization is aligned to the target in physical space by an improved Iterative Closest Point (ICP based surface registration algorithm, with the target surface structure reconstructed by a stereo camera pair; then, a markerless AR camera localization method is designed based on the Kanade-Lucas-Tomasi (KLT feature tracking algorithm and the Random Sample Consensus (RANSAC correction algorithm. Our AR camera localization method is shown to be better than the traditional marker-based and sensor-based AR environment. The demonstration system was evaluated with a plastic dummy head and the display result is satisfactory for a multiple-view observation.

Event-Based Color Segmentation With a High Dynamic Range Sensor

Directory of Open Access Journals (Sweden)

Alexandre Marcireau

2018-04-01

Full Text Available This paper introduces a color asynchronous neuromorphic event-based camera and a methodology to process color output from the device to perform color segmentation and tracking at the native temporal resolution of the sensor (down to one microsecond. Our color vision sensor prototype is a combination of three Asynchronous Time-based Image Sensors, sensitive to absolute color information. We devise a color processing algorithm leveraging this information. It is designed to be computationally cheap, thus showing how low level processing benefits from asynchronous acquisition and high temporal resolution data. The resulting color segmentation and tracking performance is assessed both with an indoor controlled scene and two outdoor uncontrolled scenes. The tracking's mean error to the ground truth for the objects of the outdoor scenes ranges from two to twenty pixels.

Pulse oximeter sensor application during neonatal resuscitation: a randomized controlled trial.

Science.gov (United States)

Louis, Deepak; Sundaram, Venkataseshan; Kumar, Praveen

2014-03-01

This study was done to compare 2 techniques of pulse oximeter sensor application during neonatal resuscitation for faster signal detection. Sensor to infant first (STIF) and then to oximeter was compared with sensor to oximeter first (STOF) and then to infant in ≥28 weeks gestations. The primary outcome was time from completion of sensor application to reliable signal, defined as stable display of heart rate and saturation. Time from birth to sensor application, time taken for sensor application, time from birth to reliable signal, and need to reapply sensor were secondary outcomes. An intention-to-treat analysis was done, and subgroup analysis was done for gestation and need for resuscitation. One hundred fifty neonates were randomized with 75 to each technique. The median (IQR) time from sensor application to detection of reliable signal was longer in STIF group compared with STOF group (16 [15-17] vs. 10 [6-18] seconds; P signal did not differ between the 2 methods (STIF: 61 [52-76] seconds; STOF: 58 [47-73] seconds [P = .09]). Time taken for signal acquisition was longer with STIF than with STOF in both subgroups. In the delivery room setting, the STOF method recognized saturation and heart rate faster than the STIF method. The time from birth to reliable signal was similar with the 2 methods.

Comparing distinct ground-based lightning location networks covering the Netherlands

Science.gov (United States)

de Vos, Lotte; Leijnse, Hidde; Schmeits, Maurice; Beekhuis, Hans; Poelman, Dieter; Evers, Läslo; Smets, Pieter

2015-04-01

Lightning can be detected using a ground-based sensor network. The Royal Netherlands Meteorological Institute (KNMI) monitors lightning activity in the Netherlands with the so-called FLITS-system; a network combining SAFIR-type sensors. This makes use of Very High Frequency (VHF) as well as Low Frequency (LF) sensors. KNMI has recently decided to replace FLITS by data from a sub-continental network operated by Météorage which makes use of LF sensors only (KNMI Lightning Detection Network, or KLDN). KLDN is compared to the FLITS system, as well as Met Office's long-range Arrival Time Difference (ATDnet), which measures Very Low Frequency (VLF). Special focus lies on the ability to detect Cloud to Ground (CG) and Cloud to Cloud (CC) lightning in the Netherlands. Relative detection efficiency of individual flashes and lightning activity in a more general sense are calculated over a period of almost 5 years. Additionally, the detection efficiency of each system is compared to a ground-truth that is constructed from flashes that are detected by both of the other datasets. Finally, infrasound data is used as a fourth lightning data source for several case studies. Relative performance is found to vary strongly with location and time. As expected, it is found that FLITS detects significantly more CC lightning (because of the strong aptitude of VHF antennas to detect CC), though KLDN and ATDnet detect more CG lightning. We analyze statistics computed over the entire 5-year period, where we look at CG as well as total lightning (CC and CG combined). Statistics that are considered are the Probability of Detection (POD) and the so-called Lightning Activity Detection (LAD). POD is defined as the percentage of reference flashes the system detects compared to the total detections in the reference. LAD is defined as the fraction of system recordings of one or more flashes in predefined area boxes over a certain time period given the fact that the reference detects at least one

Monitoring the long term stability of the IRS-P6 AWiFS sensor using the Sonoran and RVPN sites

Science.gov (United States)

Chander, Gyanesh; Sampath, Aparajithan; Angal, Amit; Choi, Taeyoung; Xiong, Xiaoxiong

2010-10-01

This paper focuses on radiometric and geometric assessment of the Indian Remote Sensing (IRS-P6) Advanced Wide Field Sensor (AWiFS) sensor using the Sonoran desert and Railroad Valley Playa, Nevada (RVPN) ground sites. Imageto- Image (I2I) accuracy and relative band-to-band (B2B) accuracy were measured. I2I accuracy of the AWiFS imagery was assessed by measuring the imagery against Landsat Global Land Survey (GLS) 2000. The AWiFS images were typically registered to within one pixel to the GLS 2000 mosaic images. The B2B process used the same concepts as the I2I, except instead of a reference image and a search image; the individual bands of a multispectral image are tested against each other. The B2B results showed that all the AWiFS multispectral bands are registered to sub-pixel accuracy. Using the limited amount of scenes available over these ground sites, the reflective bands of AWiFS sensor indicate a long-term drift in the top-of-atmosphere (TOA) reflectance. Because of the limited availability of AWiFS scenes over these ground sites, a comprehensive evaluation of the radiometric stability using these sites is not possible. In order to overcome this limitation, a cross-comparison between AWiFS and Landsat 7 (L7) Enhanced Thematic Mapper Plus (ETM+) was performed using image statistics based on large common areas observed by the sensors within 30 minutes. Regression curves and coefficients of determination for the TOA trends from these sensors were generated to quantify the uncertainty in these relationships and to provide an assessment of the calibration differences between these sensors.

AN/FSY-3 Space Fence System – Sensor Site One/Operations Center Integration Status and Sensor Site Two Planned Capability

Science.gov (United States)

Fonder, G. P.; Hack, P. J.; Hughes, M. R.

This paper covers two topics related to Space Fence System development: Sensor Site One / Operations Center construction and integration status including risk reduction integration and test efforts at the Moorestown, NJ Integrated Test Bed (ITB); and the planned capability of Sensor Site Two. The AN/FSY-3 Space Fence System is a ground-based system of S-band radars integrated with an Operations Center designed to greatly enhance the Air Force Space Surveillance network. The radar architecture is based on Digital Beam-forming. This capability permits tremendous user-defined flexibility to customize volume surveillance and track sectors instantaneously without impacting routine surveillance functions. Space Fence provides unprecedented sensitivity, coverage and tracking accuracy, and contributes to key mission threads with the ability to detect, track and catalog small objects in LEO, MEO and GEO. The system is net-centric and will seamlessly integrate into the existing Space Surveillance Network, providing services to external users—such as JSpOC—and coordinating handoffs to other SSN sites. Sensor Site One construction on the Kwajalein Atoll is in progress and nearing completion. The Operations Center in Huntsville, Alabama has been configured and will be integrated with Sensor Site One in the coming months. System hardware, firmware, and software is undergoing integration testing at the Mooretown, NJ ITB and will be deployed at Sensor Site One and the Operations Center. The preliminary design for Sensor Site Two is complete and will provide critical coverage, timeliness, and operational flexibility to the overall system.

Ground-atmosphere interactions at Gale

Science.gov (United States)

Renno, N. O.; Martinez, G.; Ramos, M.; Hallet, B.; Gómez, F. G.; Jun, I.; Fisk, M. R.; Gomez-Elvira, J.; Hamilton, V. E.; Mischna, M. A.; Sletten, R. S.; Martin-Torres, J.; De La Torre Juarez, M.; Vasavada, A. R.; Zorzano, M.

2013-12-01

We analyze variations in environmental parameters and regolith properties along Curiosity's track to determine the possible causes of an abrupt change in the thermal properties of the ground and the atmosphere observed around Sol 120, as the rover transitioned from an area of sandy soil (Rocknest) to an area of fractured bedrock terrain (Yellowknife). Curiosity is instrumented with the Rover Environmental Monitoring Station (REMS) and the Dynamic Albedo of Neutrons (DAN) sensors to measure the air temperature, the ground temperature, and the hydrogen content of the shallow subsurface along Curiosity's track. Analysis of the REMS data is used to estimate the regolith's heat budget. This analysis suggests that the abrupt decrease in the ground and atmosphere temperature and the difference between ground and air temperatures observed around Sol 120 is likely caused by an increase in the soil thermal inertia. The changes in thermal inertia have been known for some time so confirming this by the REMS package provides ground truthing. A new unexpected finding is that the regolith water content, as indicated by DAN's detection of hydrogen content, is higher in the Yellowknife soil. Another interesting finding at this site are the holes and other signs of recent geological activity in the area of fractured terrain that may reflect large volumetric variations and facilitate gas exchange between the ground and atmosphere. Near-surface volumetric changes in soil and bedrock could reflect changes in the volume of subsurface H2O, or in the partitioning of H2O among its three phases. Volume increases could also result from salt crystal growth in rock pores and soil pores associated with the adsorption of water vapor. Crystallization in pores is a significant weathering process on Earth; it could well be active on Mars. Salts also inhibits the exchange of moisture between the ground and the atmosphere, and cements the soils of arid places such as in the McMurdo Dry Valleys in

Ground motion modeling of Hayward fault scenario earthquakes II:Simulation of long-period and broadband ground motions

Energy Technology Data Exchange (ETDEWEB)

Aagaard, B T; Graves, R W; Rodgers, A; Brocher, T M; Simpson, R W; Dreger, D; Petersson, N A; Larsen, S C; Ma, S; Jachens, R C

2009-11-04

We simulate long-period (T > 1.0-2.0 s) and broadband (T > 0.1 s) ground motions for 39 scenarios earthquakes (Mw 6.7-7.2) involving the Hayward, Calaveras, and Rodgers Creek faults. For rupture on the Hayward fault we consider the effects of creep on coseismic slip using two different approaches, both of which reduce the ground motions compared with neglecting the influence of creep. Nevertheless, the scenario earthquakes generate strong shaking throughout the San Francisco Bay area with about 50% of the urban area experiencing MMI VII or greater for the magnitude 7.0 scenario events. Long-period simulations of the 2007 Mw 4.18 Oakland and 2007 Mw 4.5 Alum Rock earthquakes show that the USGS Bay Area Velocity Model version 08.3.0 permits simulation of the amplitude and duration of shaking throughout the San Francisco Bay area, with the greatest accuracy in the Santa Clara Valley (San Jose area). The ground motions exhibit a strong sensitivity to the rupture length (or magnitude), hypocenter (or rupture directivity), and slip distribution. The ground motions display a much weaker sensitivity to the rise time and rupture speed. Peak velocities, peak accelerations, and spectral accelerations from the synthetic broadband ground motions are, on average, slightly higher than the Next Generation Attenuation (NGA) ground-motion prediction equations. We attribute at least some of this difference to the relatively narrow width of the Hayward fault ruptures. The simulations suggest that the Spudich and Chiou (2008) directivity corrections to the NGA relations could be improved by including a dependence on the rupture speed and increasing the areal extent of rupture directivity with period. The simulations also indicate that the NGA relations may under-predict amplification in shallow sedimentary basins.

The advanced linked extended reconnaissance and targeting technology demonstration project

Science.gov (United States)

Cruickshank, James; de Villers, Yves; Maheux, Jean; Edwards, Mark; Gains, David; Rea, Terry; Banbury, Simon; Gauthier, Michelle

2007-06-01

The Advanced Linked Extended Reconnaissance & Targeting (ALERT) Technology Demonstration (TD) project is addressing key operational needs of the future Canadian Army's Surveillance and Reconnaissance forces by fusing multi-sensor and tactical data, developing automated processes, and integrating beyond line-of-sight sensing. We discuss concepts for displaying and fusing multi-sensor and tactical data within an Enhanced Operator Control Station (EOCS). The sensor data can originate from the Coyote's own visible-band and IR cameras, laser rangefinder, and ground-surveillance radar, as well as beyond line-of-sight systems such as a mini-UAV and unattended ground sensors. The authors address technical issues associated with the use of fully digital IR and day video cameras and discuss video-rate image processing developed to assist the operator to recognize poorly visible targets. Automatic target detection and recognition algorithms processing both IR and visible-band images have been investigated to draw the operator's attention to possible targets. The machine generated information display requirements are presented with the human factors engineering aspects of the user interface in this complex environment, with a view to establishing user trust in the automation. The paper concludes with a summary of achievements to date and steps to project completion.

GROUND SUBSIDENCE MONITORING WITH MT-InSAR AND MECHANISM INVERSION OVER XI’AN, CHINA

Directory of Open Access Journals (Sweden)

M. M. Peng

2018-04-01

Full Text Available The ancient Xi’an, China, has been suffering severe land subsidence and ground fissure hazards since the 1960s, which has affected the safety of Subways. Multi-sensor SAR data are conducted to monitor the latest complex ground deformation and its influence on subway line No.3 over Xi’an. Annual deformation rates have been retrieved to reveal the spatiotemporal evolution of ground subsidence in Xi’an city from 2013 to 2017. Meanwhile, the correlation between land subsidence and ground fissures are analyzed by retrieving the deformation differences in both sides of the fissures. Besides, the deformation along subway line No. 3 is analyzed, and the fast deformation section is quantitatively studied. Finally, a flat lying sill model with distributed contractions is implemented to model the InSAR deformation over YHZ subsidence center, which manifests that the ground deformation is mainly caused by groundwater withdrawal.

Robust Ground Target Detection by SAR and IR Sensor Fusion Using Adaboost-Based Feature Selection

Science.gov (United States)

Kim, Sungho; Song, Woo-Jin; Kim, So-Hyun

2016-01-01

Long-range ground targets are difficult to detect in a noisy cluttered environment using either synthetic aperture radar (SAR) images or infrared (IR) images. SAR-based detectors can provide a high detection rate with a high false alarm rate to background scatter noise. IR-based approaches can detect hot targets but are affected strongly by the weather conditions. This paper proposes a novel target detection method by decision-level SAR and IR fusion using an Adaboost-based machine learning scheme to achieve a high detection rate and low false alarm rate. The proposed method consists of individual detection, registration, and fusion architecture. This paper presents a single framework of a SAR and IR target detection method using modified Boolean map visual theory (modBMVT) and feature-selection based fusion. Previous methods applied different algorithms to detect SAR and IR targets because of the different physical image characteristics. One method that is optimized for IR target detection produces unsuccessful results in SAR target detection. This study examined the image characteristics and proposed a unified SAR and IR target detection method by inserting a median local average filter (MLAF, pre-filter) and an asymmetric morphological closing filter (AMCF, post-filter) into the BMVT. The original BMVT was optimized to detect small infrared targets. The proposed modBMVT can remove the thermal and scatter noise by the MLAF and detect extended targets by attaching the AMCF after the BMVT. Heterogeneous SAR and IR images were registered automatically using the proposed RANdom SAmple Region Consensus (RANSARC)-based homography optimization after a brute-force correspondence search using the detected target centers and regions. The final targets were detected by feature-selection based sensor fusion using Adaboost. The proposed method showed good SAR and IR target detection performance through feature selection-based decision fusion on a synthetic database generated

Robust Ground Target Detection by SAR and IR Sensor Fusion Using Adaboost-Based Feature Selection

Directory of Open Access Journals (Sweden)

Sungho Kim

2016-07-01

Full Text Available Long-range ground targets are difficult to detect in a noisy cluttered environment using either synthetic aperture radar (SAR images or infrared (IR images. SAR-based detectors can provide a high detection rate with a high false alarm rate to background scatter noise. IR-based approaches can detect hot targets but are affected strongly by the weather conditions. This paper proposes a novel target detection method by decision-level SAR and IR fusion using an Adaboost-based machine learning scheme to achieve a high detection rate and low false alarm rate. The proposed method consists of individual detection, registration, and fusion architecture. This paper presents a single framework of a SAR and IR target detection method using modified Boolean map visual theory (modBMVT and feature-selection based fusion. Previous methods applied different algorithms to detect SAR and IR targets because of the different physical image characteristics. One method that is optimized for IR target detection produces unsuccessful results in SAR target detection. This study examined the image characteristics and proposed a unified SAR and IR target detection method by inserting a median local average filter (MLAF, pre-filter and an asymmetric morphological closing filter (AMCF, post-filter into the BMVT. The original BMVT was optimized to detect small infrared targets. The proposed modBMVT can remove the thermal and scatter noise by the MLAF and detect extended targets by attaching the AMCF after the BMVT. Heterogeneous SAR and IR images were registered automatically using the proposed RANdom SAmple Region Consensus (RANSARC-based homography optimization after a brute-force correspondence search using the detected target centers and regions. The final targets were detected by feature-selection based sensor fusion using Adaboost. The proposed method showed good SAR and IR target detection performance through feature selection-based decision fusion on a synthetic

Ground System Extensibility Considerations

Science.gov (United States)

Miller, S. W.; Greene, E.

2017-12-01

The National Oceanic and Atmospheric Administration (NOAA) and National Aeronautics and Space Administration (NASA) are jointly acquiring the next-generation civilian weather and environmental satellite system: the Joint Polar Satellite System (JPSS). The Joint Polar Satellite System will replace the afternoon orbit component and ground processing system of the current Polar-orbiting Operational Environmental Satellites (POES) managed by NOAA. The JPSS satellites will carry a suite of sensors designed to collect meteorological, oceanographic, climatological and geophysical observations of the Earth. The ground processing system for JPSS is known as the JPSS Common Ground System (JPSS CGS). Developed and maintained by Raytheon Intelligence, Information and Services (IIS), the CGS is a multi-mission enterprise system serving NOAA, NASA and their national and international partners, such as NASA's Earth Observation System (EOS), NOAA's current POES, the Japan Aerospace Exploration Agency's (JAXA) Global Change Observation Mission - Water (GCOM-W1), and DoD's Defense Meteorological Satellite Program (DMSP). The CGS provides a wide range of support to a number of national and international missions, including command and control, mission management, data acquisition and routing, and environmental data processing and distribution. The current suite of CGS-supported missions has demonstrated the value of interagency and international partnerships to address global observation needs. With its established infrastructure and existing suite of missions, the CGS is extensible to a wider array of potential new missions. This paper will describe how the inherent scalability and extensibility of the CGS enables the addition of these new missions, with an eye on global enterprise needs in the 2020's and beyond.

Validation of Underwater Sensor Package Using Feature Based SLAM

Directory of Open Access Journals (Sweden)

Christopher Cain

2016-03-01

Full Text Available Robotic vehicles working in new, unexplored environments must be able to locate themselves in the environment while constructing a picture of the objects in the environment that could act as obstacles that would prevent the vehicles from completing their desired tasks. In enclosed environments, underwater range sensors based off of acoustics suffer performance issues due to reflections. Additionally, their relatively high cost make them less than ideal for usage on low cost vehicles designed to be used underwater. In this paper we propose a sensor package composed of a downward facing camera, which is used to perform feature tracking based visual odometry, and a custom vision-based two dimensional rangefinder that can be used on low cost underwater unmanned vehicles. In order to examine the performance of this sensor package in a SLAM framework, experimental tests are performed using an unmanned ground vehicle and two feature based SLAM algorithms, the extended Kalman filter based approach and the Rao-Blackwellized, particle filter based approach, to validate the sensor package.

Validation of Underwater Sensor Package Using Feature Based SLAM

Science.gov (United States)

Cain, Christopher; Leonessa, Alexander

2016-01-01

Robotic vehicles working in new, unexplored environments must be able to locate themselves in the environment while constructing a picture of the objects in the environment that could act as obstacles that would prevent the vehicles from completing their desired tasks. In enclosed environments, underwater range sensors based off of acoustics suffer performance issues due to reflections. Additionally, their relatively high cost make them less than ideal for usage on low cost vehicles designed to be used underwater. In this paper we propose a sensor package composed of a downward facing camera, which is used to perform feature tracking based visual odometry, and a custom vision-based two dimensional rangefinder that can be used on low cost underwater unmanned vehicles. In order to examine the performance of this sensor package in a SLAM framework, experimental tests are performed using an unmanned ground vehicle and two feature based SLAM algorithms, the extended Kalman filter based approach and the Rao-Blackwellized, particle filter based approach, to validate the sensor package. PMID:26999142

Pengembangan OSD (On Screen Display dengan Penambahan Menu untuk Aplikasi pada Semi Autonomous Mobile Robot dengan Lengan untuk Mengambil Objek

Directory of Open Access Journals (Sweden)

Muhammad Saiful Hak

2017-01-01

Full Text Available Tugas Akhir ini membahas pengembangan OSD (On Screen Display dengan sistem FPV (First Person View yang bertujuan untuk mendukung kinerja sebuah RC (Remote Control atau mobile robot dengan cara mengambil data pada RC atau mobile robot tersebut. Penggunaan sensor pad a modul OSD ini terbatas, sehingga dilakukan sebuah pengembangan dengan penambahan pengkabelan dan pemrograman menggunakan kompiler Arduino. Dalam sistem ini, OSD yang dipakai adalah dua buah minimOSD yang telah dirancang dengan penambahan beberapa fitur menu sensor. Pada minimOSD yang pertama data GPS (Global Positioning System berupa posisi lintang dan bujur didapat dari APM (ArduPilot Mega yang diprogram menggunakan minimOSD extra. Pada minimOSD yang kedua didapat data sensor ultrasonik dan posisi lengan robot yang dikirim oleh Arduino Mega pada mobile robot menggunakan pengiriman serial. Sensor suhu, level baterai dan data waktu diperoleh dari penambahan pengkabelan pada pin-pin ATMega328. Hasil olah data sensor pada minimOSD pertama dan kedua yang berupa data visual digabung dan dikirim menuju layar monitor FPV menggunakan video transmiter. Animasi data yang ditampilkan mempunyai batas sebesar 256 data karakter, sehingga posisi lengan robot dan sensor ultrasonik hanya bisa digambarkan berupa perbandingan skala tingkatan dan data teks, sedangkan data sensor yang lain ditampilkan sesuai hasil olah data sebenarnya.

Photonic crystal fiber interferometric pH sensor based on polyvinyl alcohol/polyacrylic acid hydrogel coating.

Science.gov (United States)

Hu, Pengbing; Dong, Xinyong; Wong, Wei Chang; Chen, Li Han; Ni, Kai; Chan, Chi Chiu

2015-04-01

We present a simple photonic crystal fiber interferometer (PCFI) that operates in reflection mode for pH measurement. The sensor is made by coating polyvinyl alcohol/polyacrylic acid (PVA/PAA) hydrogel onto the surface of the PCFI, constructed by splicing a stub of PCF at the distal end of a single-mode fiber with its free end airhole collapsed. The experimental results demonstrate a high average sensitivity of 0.9 nm/pH unit for the 11 wt.% PVA/PAA coated sensor in the pH range from 2.5 to 6.5. The sensor also displays high repeatability and stability and low cross-sensitivity to temperature. Fast, reversible rise and fall times of 12 s and 18 s, respectively, are achieved for the sensor time response.

Exploring the impact of big data in economic geology using cloud-based synthetic sensor networks

Science.gov (United States)

Klump, J. F.; Robertson, J.

2015-12-01

In a market demanding lower resource prices and increasing efficiencies, resources companies are increasingly looking to the realm of real-time, high-frequency data streams to better measure and manage their minerals processing chain, from pit to plant to port. Sensor streams can include real-time drilling engineering information, data streams from mining trucks, and on-stream sensors operating in the plant feeding back rich chemical information. There are also many opportunities to deploy new sensor streams - unlike environmental monitoring networks, the mine environment is not energy- or bandwidth-limited. Although the promised efficiency dividends are inviting, the path to achieving these is difficult to see for most companies. As well as knowing where to invest in new sensor technology and how to integrate the new data streams, companies must grapple with risk-laden changes to their established methods of control to achieve maximum gains. What is required is a sandbox data environment for the development of analysis and control strategies at scale, allowing companies to de-risk proposed changes before actually deploying them to a live mine environment. In this presentation we describe our approach to simulating real-time scaleable data streams in a mine environment. Our sandbox consists of three layers: (a) a ground-truth layer that contains geological models, which can be statistically based on historical operations data, (b) a measurement layer - a network of RESTful synthetic sensor microservices which can simulate measurements of ground-truth properties, and (c) a control layer, which integrates the sensor streams and drives the measurement and optimisation strategies. The control layer could be a new machine learner, or simply a company's existing data infrastructure. Containerisation allows rapid deployment of large numbers of sensors, as well as service discovery to form a dynamic network of thousands of sensors, at a far lower cost than physically

Miniaturized pH Sensors Based on Zinc Oxide Nanotubes/Nanorods

Directory of Open Access Journals (Sweden)

Magnus Willander

2009-11-01

Full Text Available ZnO nanotubes and nanorods grown on gold thin film were used to create pH sensor devices. The developed ZnO nanotube and nanorod pH sensors display good reproducibility, repeatability and long-term stability and exhibit a pH-dependent electrochemical potential difference versus an Ag/AgCl reference electrode over a large dynamic pH range. We found the ZnO nanotubes provide sensitivity as high as twice that of the ZnO nanorods, which can be ascribed to the fact that small dimensional ZnO nanotubes have a higher level of surface and subsurface oxygen vacancies and provide a larger effective surface area with higher surface-to-volume ratio as compared to ZnO nanorods, thus affording the ZnO nanotube pH sensor a higher sensitivity. Experimental results indicate ZnO nanotubes can be used in pH sensor applications with improved performance. Moreover, the ZnO nanotube arrays may find potential application as a novel material for measurements of intracellular biochemical species within single living cells.

Identification of Cyclin A Binders with a Fluorescent Peptide Sensor.

Science.gov (United States)

Pazos, Elena; Mascareñas, José L; Vázquez, M Eugenio

2016-01-01

A peptide sensor that integrates the 4-dimethylaminophthalimide (4-DMAP) fluorophore in a short cyclin A binding sequence displays a large fluorescence emission increase upon interacting with the cyclin A Binding Groove (CBG). Competitive displacement assays of this probe allow the straightforward identification of peptides that interact with the CBG, which could potentially block the recognition of CDK/cyclin A kinase substrates.