WorldWideScience

Sample records for ground based instruments

  1. Calibration of Ground-based Lidar instrument

    DEFF Research Database (Denmark)

    Villanueva, Héctor; Gómez Arranz, Paula

    This report presents the result of the lidar calibration performed for the given Ground-based Lidar at DTU’s test site for large wind turbines at Høvsøre, Denmark. Calibration is here understood as the establishment of a relation between the reference wind speed measurements with measurement unce...

  2. Calibration of Ground -based Lidar instrument

    DEFF Research Database (Denmark)

    Villanueva, Héctor; Yordanova, Ginka

    This report presents the result of the lidar calibration performed for the given Ground-based Lidar at DTU’s test site for large wind turbines at Høvsøre, Denmark. Calibration is here understood as the establishment of a relation between the reference wind speed measurements with measurement unce...

  3. Calibration of Ground-based Lidar instrument

    DEFF Research Database (Denmark)

    Yordanova, Ginka; Gómez Arranz, Paula

    This report presents the result of the lidar calibration performed for the given Ground-based Lidar at DTU’s test site for large wind turbines at Høvsøre, Denmark. Calibration is here understood as the establishment of a relation between the reference wind speed measurements with measurement...... uncertainties provided by measurement standard and corresponding lidar wind speed indications with associated measurement uncertainties. The lidar calibration concerns the 10 minute mean wind speed measurements. The comparison of the lidar measurements of the wind direction with that from wind vanes...

  4. Calibration of Ground-based Lidar instrument

    DEFF Research Database (Denmark)

    Yordanova, Ginka; Gómez Arranz, Paula

    This report presents the result of a test of a ground-based lidar of other type. The test was performed at DTU’s test site for large wind turbines at Høvsøre, Denmark. The result as an establishment of a relation between the reference wind speed measurements with measurement uncertainties provided...... by measurement standard and corresponding lidar wind speed indications with associated measurement uncertainties. The comparison of the lidar measurements of the wind direction with that from the wind vanes is also given....

  5. Calibration of Ground -based Lidar instrument

    DEFF Research Database (Denmark)

    Villanueva, Héctor; Yordanova, Ginka

    This report presents the result of the lidar calibration performed for the given Ground-based Lidar at DTU’s test site for large wind turbines at Høvsøre, Denmark. Calibration is here understood as the establishment of a relation between the reference wind speed measurements with measurement...... uncertainties provided by measurement standard and corresponding lidar wind speed indications with associated measurement uncertainties. The lidar calibration concerns the 10 minute mean wind speed measurements. The comparison of the lidar measurements of the wind direction with that from wind vanes...

  6. Calibration of Ground-based Lidar instrument

    DEFF Research Database (Denmark)

    Yordanova, Ginka; Gómez Arranz, Paula

    This report presents the result of the lidar calibration performed for the given Ground-based Lidar at DTU’s test site for large wind turbines at Høvsøre, Denmark. Calibration is here understood as the establishment of a relation between the reference wind speed measurements with measurement...... uncertainties provided by measurement standard and corresponding lidar wind speed indications with associated measurement uncertainties. The lidar calibration concerns the 10 minute mean wind speed measurements. The comparison of the lidar measurements of the wind direction with that from wind vanes...

  7. Calibration of Ground -based Lidar instrument

    DEFF Research Database (Denmark)

    Villanueva, Héctor; Georgieva Yankova, Ginka

    This report presents the result of the lidar calibration performed for the given Ground-based Lidar at DTU’s test site for large wind turbines at Høvsøre, Denmark. Calibration is here understood as the establishment of a relation between the reference wind speed measurements with measurement...... uncertainties provided by measurement standard and corresponding lidar wind speed indications with associated measurement uncertainties. The lidar calibration concerns the 10 minute mean wind speed measurements. The comparison of the lidar measurements of the wind direction with that from wind vanes...

  8. Project management for complex ground-based instruments: MEGARA plan

    Science.gov (United States)

    García-Vargas, María. Luisa; Pérez-Calpena, Ana; Gil de Paz, Armando; Gallego, Jesús; Carrasco, Esperanza; Cedazo, Raquel; Iglesias, Jorge

    2014-08-01

    The project management of complex instruments for ground-based large telescopes is a challenge itself. A good management is a clue for project success in terms of performance, schedule and budget. Being on time has become a strict requirement for two reasons: to assure the arrival at the telescope due to the pressure on demanding new instrumentation for this first world-class telescopes and to not fall in over-costs. The budget and cash-flow is not always the expected one and has to be properly handled from different administrative departments at the funding centers worldwide distributed. The complexity of the organizations, the technological and scientific return to the Consortium partners and the participation in the project of all kind of professional centers working in astronomical instrumentation: universities, research centers, small and large private companies, workshops and providers, etc. make the project management strategy, and the tools and procedures tuned to the project needs, crucial for success. MEGARA (Multi-Espectrógrafo en GTC de Alta Resolución para Astronomía) is a facility instrument of the 10.4m GTC (La Palma, Spain) working at optical wavelengths that provides both Integral-Field Unit (IFU) and Multi-Object Spectrograph (MOS) capabilities at resolutions in the range R=6,000-20,000. The project is an initiative led by Universidad Complutense de Madrid (Spain) in collaboration with INAOE (Mexico), IAA-CSIC (Spain) and Universidad Politécnica de Madrid (Spain). MEGARA is being developed under contract with GRANTECAN.

  9. Biosensors for EVA: Improved Instrumentation for Ground-based Studies

    Science.gov (United States)

    Soller, B.; Ellerby, G.; Zou, F.; Scott, P.; Jin, C.; Lee, S. M. C.; Coates, J.

    2010-01-01

    During lunar excursions in the EVA suit, real-time measurement of metabolic rate is required to manage consumables and guide activities to ensure safe return to the base. Metabolic rate, or oxygen consumption (VO2), is normally measured from pulmonary parameters but cannot be determined with standard techniques in the oxygen-rich environment of a spacesuit. Our group has developed novel near infrared spectroscopic (NIRS) methods to calculate muscle oxygen saturation (SmO 2), hematocrit, and pH, and we recently demonstrated that we can use our NIRS sensor to measure VO 2 on the leg during cycling. Our NSBRI project has 4 objectives: (1) increase the accuracy of the metabolic rate calculation through improved prediction of stroke volume; (2) investigate the relative contributions of calf and thigh oxygen consumption to metabolic rate calculation for walking and running; (3) demonstrate that the NIRS-based noninvasive metabolic rate methodology is sensitive enough to detect decrement in VO 2 in a space analog; and (4) improve instrumentation to allow testing within a spacesuit. Over the past year we have made progress on all four objectives, but the most significant progress was made in improving the instrumentation. The NIRS system currently in use at JSC is based on fiber optics technology. Optical fiber bundles are used to deliver light from a light source in the monitor to the patient, and light reflected back from the patient s muscle to the monitor for spectroscopic analysis. The fiber optic cables are large and fragile, and there is no way to get them in and out of the test spacesuit used for ground-based studies. With complimentary funding from the US Army, we undertook a complete redesign of the sensor and control electronics to build a novel system small enough to be used within the spacesuit and portable enough to be used by a combat medic. In the new system the filament lamp used in the fiber optic system was replaced with a novel broadband near infrared

  10. Biosensors for EVA: Improved Instrumentation for Ground-based Studies

    Science.gov (United States)

    Soller, B.; Ellerby, G.; Zou, F.; Scott, P.; Jin, C.; Lee, S. M. C.; Coates, J.

    2010-01-01

    During lunar excursions in the EVA suit, real-time measurement of metabolic rate is required to manage consumables and guide activities to ensure safe return to the base. Metabolic rate, or oxygen consumption (VO2), is normally measured from pulmonary parameters but cannot be determined with standard techniques in the oxygen-rich environment of a spacesuit. Our group has developed novel near infrared spectroscopic (NIRS) methods to calculate muscle oxygen saturation (SmO 2), hematocrit, and pH, and we recently demonstrated that we can use our NIRS sensor to measure VO 2 on the leg during cycling. Our NSBRI project has 4 objectives: (1) increase the accuracy of the metabolic rate calculation through improved prediction of stroke volume; (2) investigate the relative contributions of calf and thigh oxygen consumption to metabolic rate calculation for walking and running; (3) demonstrate that the NIRS-based noninvasive metabolic rate methodology is sensitive enough to detect decrement in VO 2 in a space analog; and (4) improve instrumentation to allow testing within a spacesuit. Over the past year we have made progress on all four objectives, but the most significant progress was made in improving the instrumentation. The NIRS system currently in use at JSC is based on fiber optics technology. Optical fiber bundles are used to deliver light from a light source in the monitor to the patient, and light reflected back from the patient s muscle to the monitor for spectroscopic analysis. The fiber optic cables are large and fragile, and there is no way to get them in and out of the test spacesuit used for ground-based studies. With complimentary funding from the US Army, we undertook a complete redesign of the sensor and control electronics to build a novel system small enough to be used within the spacesuit and portable enough to be used by a combat medic. In the new system the filament lamp used in the fiber optic system was replaced with a novel broadband near infrared

  11. VME-based remote instrument control without ground loops

    CERN Document Server

    Belleman, J; González, J L

    1997-01-01

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

  12. Ground-based astronomical instrument for planetary protection

    Science.gov (United States)

    Kendrick, Richard L.; Bennett, Dave; Bold, Matthew

    2014-07-01

    Planetary protection consists of the measurement and characterization of near-earth objects including earth threatening asteroids and earth orbiting debris. The Lockheed Martin STAR Labs in Palo Alto California is developing new astronomical instruments for use in planetary protection. The observation of asteroids is standard for astronomical facilities and there are available instruments designed with this specific science mission in mind. Orbital debris observation and characterization has a somewhat different set of requirements and includes large fields of view with simultaneous spectro-polarimetric data on multiple closely spaced objects. Orbital debris is comprised of spent rocket bodies, rocket fairing covers, paint chips, various satellite components, debris from satellite collisions and explosions and nonoperational satellites. The debris is present in all orbital planes from Low Earth orbit out to the geosynchronous graveyard orbit. We concentrate our effort on the geosynchronous and nearby orbits. This is because typical groundbased astronomical telescopes are built to track at sidereal rates and not at the 1 degree per second rates that are required to track low earth orbiting objects. The orbital debris materials include aluminum, mylar, solar cell materials, composite matrix material and other materials that are used in the fabrication of satellites and launch vehicles. These materials typically have spectral features in different wavebands than asteroids which are mostly composed of materials with molecular absorption bands such as in H2O. This will drive an orbital debris material identification instrument to wavebands and resolutions that are typically not used in asteroid observations.

  13. Spectrally selective surfaces for ground and space-based instrumentation: support for a resource base

    Science.gov (United States)

    McCall, Susan H.; Sinclair, R. Lawrence; Pompea, Stephen M.; Breault, Robert P.

    1993-11-01

    The performance of space telescopes, space instruments, and space radiator systems depends critically upon the selection of appropriate spectrally selective surfaces. Many space programs have suffered severe performance limitations, schedule setbacks, and spent hundreds of thousands of dollars in damage control because of a lack of readily-accessible, accurate data on the properties of spectrally selective surfaces, particularly black surfaces. A Canadian effort is underway to develop a resource base (database and support service) to help alleviate this problem. The assistance of the community is required to make the resource base comprehensive and useful to the end users. The paper aims to describe the objectives of this project. In addition, a request for information and support is made for various aspects of the project. The resource base will be useful for both ground and space-based instrumentation.

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

    Science.gov (United States)

    Papadopoulos, K.

    2014-12-01

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

  15. Plans of a test bed for ionospheric modelling based on Fennoscandian ground-based instrumentation

    Science.gov (United States)

    Kauristie, Kirsti; Kero, Antti; Verronen, Pekka T.; Aikio, Anita; Vierinen, Juha; Lehtinen, Markku; Turunen, Esa; Pulkkinen, Tuija; Virtanen, Ilkka; Norberg, Johannes; Vanhamäki, Heikki; Kallio, Esa; Kestilä, Antti; Partamies, Noora; Syrjäsuo, Mikko

    2016-07-01

    One of the recommendations for teaming among research groups in the COSPAR/ILWS roadmap is about building test beds in which coordinated observing supports model development. In the presentation we will describe a test bed initiative supporting research on ionosphere-thermosphere-magnetosphere interactions. The EISCAT incoherent scatter radars with their future extension, EISCAT3D, form the backbone of the proposed system. The EISCAT radars are surrounded by versatile and dense arrays of ground-based instrumentation: magnetometers and auroral cameras (the MIRACLE and IMAGE networks), ionospheric tomography receivers (the TomoScand network) and other novel technology for upper atmospheric probing with radio waves (e.g. the KAIRA facility, riometers and the ionosonde maintained by the Sodankylä Geophysical Observatory). As a new opening, close coordination with the Finnish national cubesat program is planned. We will investigate opportunities to establish a cost efficient nanosatellite program which would support the ground-based observations in a systematic and persistent manner. First experiences will be gathered with the Aalto-1 and Aalto-2 satellites, latter of which will be the Finnish contribution to the international QB50 mission. We envisage close collaboration also in the development of data analysis tools with the goal to integrate routines and models from different research groups to one system, where the different elements support each other. In the longer run we are aiming for a modelling framework with observational guidance which gives a holistic description on ionosphere-thermosphere processes and this way enables reliable forecasts on upper atmospheric space weather activity.

  16. CRRES/Ground-based multi-instrument observations of an interval of substorm activity

    Directory of Open Access Journals (Sweden)

    T. K. Yeoman

    Full Text Available Observations are presented of data taken during a 3-h interval in which five clear substorm onsets/intensifications took place. During this interval ground-based data from the EISCAT incoherent scatter radar, a digital CCD all sky camera, and an extensive array of magnetometers were recorded. In addition data from the CRRES and DMSP spacecraft, whose footprints passed over Scandinavia very close to most of the ground-based instrumentation, are available. The locations and movements of the substorm current system in latitude and longitude, determined from ground and spacecraft magnetic field data, have been correlated with the locations and propagation of increased particle precipitation in the E-region at EISCAT, increased particle fluxes measured by CRRES and DMSP, with auroral luminosity and with ionospheric convection velocities. The onsets and propagation of the injection of magnetospheric particle populations and auroral luminosity have been compared. CRRES was within or very close to the substorm expansion phase onset sector during the interval. The onset region was observed at low latitudes on the ground, and has been confirmed to map back to within L=7 in the magnetotail. The active region was then observed to propagate tailward and poleward. Delays between the magnetic signature of the substorm field aligned currents and field dipolarisation have been measured. The observations support a near-Earth plasma instability mechanism for substorm expansion phase onset.

  17. Unattended instruments for ground-based hyperspectral measurements: development and application for plant photosynthesis monitoring

    Science.gov (United States)

    Cogliati, S.; Rossini, M.; Meroni, M.; Barducci, A.; Julitta, T.; Colombo, R.

    2011-12-01

    The aim of the present work is the development of ground-based hyperspectral systems capable of collecting continuous and long-term hyperspectral measurements of the Earth-surface. The development of such instruments includes the optical design, the development of the data acquisition (Auto3S) and processing software as well as the definition of the calibration procedures. In particular an in-field calibration methodologie based on the comparison between field spectra and data modeled using Radiative Transfer (RT) approach has been proposed to regularly upgrade instrument calibration coefficients. Two different automatic spectrometric systems have been developed: the HyperSpectral Irradiometer (HSI) [Meroni et al., 2011] and the Multiplexer Radiometer Irradiometer (MRI) [Cogliati, 2011]. Both instruments are able to continuously measure: sun incoming irradiance (ETOT) and irradiance (ES, HSI)/radiance (LS, MRI) upwelling from the investigated surface. Both instruments employ two Ocean Optics HR4000 spectrometers sharing the same optical signal that allow to simultaneously collect "fine" (1 nm Full Width at Half Maximum, FWHM) spectra in the 400-1000 nm rangeand "ultra-fine" (0.1 nm FWHM) spectra within the 700-800 nm. The collected optical data allow to estimate biochemical/structural properties of vegetation (e.g. NDVI) as well as its photosynthetic efficiency through the Photochemical Reflectance Index (PRI) and the analysis of sun-induced chlorophyll Fluorescence in the O2-A Fraunhofer line (F@760). The automatic instruments were operated in coordination with eddy covariance flux tower measurements of carbon exchange in the framework of several field campaigns: HSI was employed in a subalpine pasture (2009-ongoing) (www.phenoalp.eu) while MRI was employed in 2009 in the Sen3Exp field survey promoted by the European Space Agency as consolidation study to the future mission Sentinel-3. Results show that the proposed instruments succeeded in collecting continuous

  18. Atmospheric aerosol characterization with a ground-based SPEX spectropolarimetric instrument

    Directory of Open Access Journals (Sweden)

    G. van Harten

    2014-06-01

    Full Text Available Characterization of atmospheric aerosols is important for understanding their impact on health and climate. A wealth of aerosol parameters can be retrieved from multi-angle, multi-wavelength radiance and polarization measurements of the clear sky. We developed a ground-based SPEX instrument (groundSPEX for accurate spectropolarimetry, based on the passive, robust, athermal and snapshot spectral polarization modulation technique, and hence ideal for field deployment. It samples the scattering phase function in the principal plane in an automated fashion, using a motorized pan/tilt unit and automatic exposure time detection. Extensive radiometric and polarimetric calibrations were performed, yielding values for both random noise and systematic uncertainties. The absolute polarimetric accuracy at low degrees of polarization is established to be ~ 5 × 10−3. About 70 measurement sequences have been performed throughout four clear-sky days at Cabauw, the Netherlands. Several aerosol parameters were retrieved: aerosol optical thickness, effective radius, and complex refractive index for fine and coarse mode. The results are in good agreement with the co-located AERONET products, with a correlation coefficient of ρ = 0.932 for the total aerosol optical thickness at 550 nm.

  19. Cloud and precipitation properties from ground-based remote sensing instruments in East Antarctica

    Directory of Open Access Journals (Sweden)

    I. V. Gorodetskaya

    2014-07-01

    Full Text Available A new comprehensive cloud-precipitation-meteorological observatory has been established at Princess Elisabeth base, located in the escarpment zone of Dronning Maud Land, East Antarctica. The observatory consists of a set of ground-based remote sensing instruments (ceilometer, infrared pyrometer and vertically profiling precipitation radar combined with automatic weather station measurements of near-surface meteorology, radiative fluxes, and snow accumulation. In this paper, the observatory is presented and the potential for studying the evolution of clouds and precipitating systems is illustrated by case studies. It is shown that the synergetic use of the set of instruments allows for distinguishing ice, mixed-phase and precipitating clouds, including some information on their vertical extent. In addition, wind-driven blowing snow events can be distinguished from deeper precipitating systems. Cloud properties largely affect the surface radiative fluxes, with liquid-containing clouds dominating the radiative impact. A statistical analysis of all measurements (in total 14 months mainly occurring in summer/autumn indicates that these liquid-containing clouds occur during as much as 20% of the cloudy periods. The cloud occurrence shows a strong bimodal distribution with clear sky conditions 51% of the time and complete overcast conditions 35% of the time. Snowfall occurred 17% of the cloudy periods with a predominance of light precipitation and only rare events with snowfall > 1 mm h−1 water equivalent (w.e.. Three of such intensive snowfall events occurred during 2011 contributing to anomalously large annual snow accumulation. This is the first deployment of a precipitation radar in Antarctica allowing to assess the contribution of the snowfall to the local surface mass balance. It is shown that on the one hand large accumulation events (>10 mm w.e. day−1 during the measurement period of 26 months were always associated with snowfall, but that

  20. Analysis of the substorm trigger phase using multiple ground-based instrumentation

    Energy Technology Data Exchange (ETDEWEB)

    Kauristie, K.; Pulkkinen, T.I.; Pellinen, R.J. [Finnish Meteorological Institute, Helsinki (Finland)] [and others

    1995-08-01

    The authors discuss in detail the observation of an event of auroral activity fading during the trigger, or growth phase of a magnetic storm. This event was observed by all-sky cameras, EISCAT radar and magnetometers, riometers, and pulsation magnetometers, from ground based stations in Finland and Scandanavia. Based on their detailed analysis, they present a possible cause for the observed fading.

  1. Comparing Aerosol Retrievals from Ground-Based Instruments at the Impact-Pm Field Campaign

    Science.gov (United States)

    Kupinski, M.; Bradley, C. L.; Kalashnikova, O. V.; Xu, F.; Diner, D. J.; Clements, C. B.; Camacho, C.

    2016-12-01

    Detection of aerosol types, components having different size and chemical composition, over urban areas is important for understanding their impact on health and climate. In particular, sustained contact with size-differentiated airborne particulate matter: PM10 and PM2.5 can lead to adverse health effects such as asthma attacks, heart and lung diseases, and premature mortality. Multi-angular polarimetric measurements have been advocated in recent years as an additional tool to better understand and retrieve the aerosol properties needed for improved predictions of aerosol impart on air quality and climate. We deployed the ground-based Multiangle SpectroPolarimetric Imager (GroundMSPI) for accurate spectropolarimetric and radiance measurements co-located with the AERONET CIMEL sun photometer and a Halo Doppler 18 m resolution lidar from San José State University at the Garland-Fresno Air Quality supersite in Fresno, CA on July 7 during the Imaging Polarimetric Assessment and Characterization of Tropospheric Particulate Matter (ImPACT-PM) field experiment. GroundMSPI sampled the atmospheric scattering phase function in and 90 degrees out of the principal plane every 15 minutes in an automated manner, utilizing the 2-axis gimbal mount in elevation and azimuth. The goal of this work is verify atmospheric measurement of GroundMSPI with the coincident CIMEL sun photometer and ground-based lidar. Diffuse-sky radiance measurements of GroundMSPI are compared with the CIMEL sun photometer throughout the day. AERONET aerosol parameters such as size, shape, and index of refraction as well as lidar aerosol extinction profiles will be used in a forward radiative transfer model to compare with GroundMSPI observations and optimize these parameters to best match GroundMSPI data.

  2. Determination of the Characteristics of Ground-Based IR Spectral Instrumentation for Environmental Monitoring of the Atmosphere

    Science.gov (United States)

    Makarova, M. V.; Poberovskii, A. V.; Hase, F.; Timofeyev, Yu. M.; Imhasin, Kh. Kh.

    2016-07-01

    This is a study of the spectral characteristics of a ground-based spectral system consisting of an original system for tracking the sun developed at St. Petersburg State University and a Bruker IFS125HR Fourier spectrometer. The importance of accounting for the actual instrument function of the spectral system during processing of ground-based IR spectra of direct solar radiation is illustrated by the example of determining the overall abundance of methane in the atmosphere. Spectral intervals are proposed for taking spectra of direct solar radiation with an HBr cell, which yield information on the parameters of the ground-based system, while simultaneously checking the alignment of the system for each spectrum of the atmosphere.

  3. Validation of ACE and OSIRIS ozone and NO2 measurements using ground-based instruments at 80° N

    Directory of Open Access Journals (Sweden)

    A. Pazmino

    2012-05-01

    Full Text Available The Optical Spectrograph and Infra-Red Imager System (OSIRIS and the Atmospheric Chemistry Experiment (ACE have been taking measurements from space since 2001 and 2003, respectively. This paper presents intercomparisons between ozone and NO2 measured by the ACE and OSIRIS satellite instruments and by ground-based instruments at the Polar Environment Atmospheric Research Laboratory (PEARL, which is located at Eureka, Canada (80° N, 86° W and is operated by the Canadian Network for the Detection of Atmospheric Change (CANDAC. The ground-based instruments included in this study are four zenith-sky differential optical absorption spectroscopy (DOAS instruments, one Bruker Fourier transform infrared spectrometer (FTIR and four Brewer spectrophotometers. Ozone total columns measured by the DOAS instruments were retrieved using new Network for the Detection of Atmospheric Composition Change (NDACC guidelines and agree to within 3.2%. The DOAS ozone columns agree with the Brewer spectrophotometers with mean relative differences that are smaller than 1.5%. This suggests that for these instruments the new NDACC data guidelines were successful in producing a homogenous and accurate ozone dataset at 80° N. Satellite 14–52 km ozone and 17–40 km NO2 partial columns within 500 km of PEARL were calculated for ACE-FTS Version 2.2 (v2.2 plus updates, ACE-FTS v3.0, ACE-MAESTRO (Measurements of Aerosol Extinction in the Stratosphere and Troposphere Retrieved by Occultation v1.2 and OSIRIS SaskMART v5.0x ozone and Optimal Estimation v3.0 NO2 data products. The new ACE-FTS v3.0 and the validated ACE-FTS v2.2 partial columns are nearly identical, with mean relative differences of 0.0 ± 0.2% and −0.2 ± 0.1% for v2.2 minus v3.0 ozone and NO2, respectively. Ozone columns were constructed from 14–52 km satellite and 0–14 km ozonesonde partial columns and compared with the ground-based total column measurements. The satellite-plus-sonde measurements agree

  4. Trend analysis of greenhouse gases over Europe measured by a network of ground-based remote FTIR instruments

    Directory of Open Access Journals (Sweden)

    T. Gardiner

    2008-11-01

    Full Text Available This paper describes the statistical analysis of annual trends in long term datasets of greenhouse gas measurements taken over ten or more years. The analysis technique employs a bootstrap resampling method to determine both the long-term and intra-annual variability of the datasets, together with the uncertainties on the trend values. The method has been applied to data from a European network of ground-based solar FTIR instruments to determine the trends in the tropospheric, stratospheric and total columns of ozone, nitrous oxide, carbon monoxide, methane, ethane and HCFC-22. The suitability of the method has been demonstrated through statistical validation of the technique, and comparison with ground-based in-situ measurements and 3-D atmospheric models.

  5. The UVscope instrument in the framework of ground-based cosmic ray fluorescence observatories

    Energy Technology Data Exchange (ETDEWEB)

    Maccarone, M.C., E-mail: Maccarone@ifc.inaf.i [Istituto di Astrofisica Spaziale e Fisica Cosmica di Palermo, IASF-PA/INAF, Via Ugo La Malfa 153, 90146 Palermo (Italy); Istituto Nazionale di Fisica Nucleare, INFN, Sez. Catania, Via Santa Sofia 64, 95123 Catania (Italy); Catalano, O.; La Rosa, G.; Segreto, A. [Istituto di Astrofisica Spaziale e Fisica Cosmica di Palermo, IASF-PA/INAF, Via Ugo La Malfa 153, 90146 Palermo (Italy); Istituto Nazionale di Fisica Nucleare, INFN, Sez. Catania, Via Santa Sofia 64, 95123 Catania (Italy); Caruso, R.; Insolia, A. [Istituto Nazionale di Fisica Nucleare, INFN, Sez. Catania, Via Santa Sofia 64, 95123 Catania (Italy); Dipartimento di Fisica e Astronomia, Universita di Catania, Via Santa Sofia 64, 95123 Catania (Italy)

    2009-05-15

    UVscope is a stand-alone portable photon detector developed at IASF-PA as experimental support activity in the high-energy cosmic rays field. The apparatus is designed to measure the sky transparency and the diffuse night sky background light in the UltraViolet wavelength range where the atmosphere fluorescence process mainly takes place. In particular, UVscope can measure the relative intensity of the main fluorescence lines with respect to the background light allowing us to explore for a possible correlation between their variations and the variations of the environmental conditions (atmospheric and geographical). Taking advantage of the comparative information coming from the fluorescence detectors and the monitoring facilities available on site, feasibility and significance of UVscope are being tested at the Pierre Auger Southern Observatory; if this investigation phase will be successful, UVscope could be used as a relatively simple and complementary instrumentation at the Northern site of the Pierre Auger Observatory, currently under definition. The present version of the UVscope instrument, with angular aperture of 6.5 deg., is based on a multi-anode photomultiplier: its absolute calibration with the Vega star and preliminary results from measurements 'on field' are here reported.

  6. Intercomparison of stratospheric nitrogen dioxide columns retrieved from ground-based DOAS and FTIR and satellite DOAS instruments over the subtropical Izana station

    OpenAIRE

    Robles-Gonzalez, Cristina; Navarro-Comas, Mónica; Puentedura, Olga; Schneider, Matthias; Hase, Frank; Garcia, Omaira; Blumenstock, Thomas; Gil-Ojeda, Manuel

    2016-01-01

    A 13-year analysis (2000–2012) of the NO2 vertical column densities derived from ground-based (GB) instruments and satellites has been carried out over the Izaña NDACC (Network for the Detection of the Atmospheric Composition Change) subtropical site. Ground-based DOAS (differential optical absorption spectroscopy) and FTIR (Fourier transform infrared spectroscopy) instruments are intercompared to test mutual consistency and then used for validation of stratospheric NO2 fro...

  7. A joint Cluster and ground-based instruments study of two magnetospheric substorm events on 1 September 2002

    Directory of Open Access Journals (Sweden)

    N. C. Draper

    2004-12-01

    Full Text Available We present a coordinated ground- and space-based multi-instrument study of two magnetospheric substorm events that occurred on 1 September 2002, during the interval from 18:00 UT to 24:00 UT. Data from the Cluster and Polar spacecraft are considered in combination with ground-based magnetometer and HF radar data. During the first substorm event the Cluster spacecraft, which were in the Northern Hemisphere lobe, are to the west of the main region affected by the expansion phase. Nevertheless, substorm signatures are seen by Cluster at 18:25 UT (just after the expansion phase onset as seen on the ground at 18:23 UT, despite the ~5 RE} distance of the spacecraft from the plasma sheet. The Cluster spacecraft then encounter an earthward-moving diamagnetic cavity at 19:10 UT, having just entered the plasma sheet boundary layer. The second substorm expansion phase is preceded by pseudobreakups at 22:40 and 22:56 UT, at which time thinning of the near-Earth, L=6.6, plasma sheet occurs. The expansion phase onset at 23:05 UT is seen simultaneously in the ground magnetic field, in the magnetotail and at Polar's near-Earth position. The response in the ionospheric flows occurs one minute later. The second substorm better fits the near-Earth neutral line model for substorm onset than the cross-field current instability model.

    Key words. Magnetospheric physics (Magnetosphereionosphere interactions; Magnetic reconnection; Auroral phenomenon

  8. Absolute calibration and beam reconstruction of MITO (a ground-based instrument in the millimetric region)

    CERN Document Server

    Savini, G; Battistelli, E S; De Petris, M; Lamagna, L; Luzzi, G; Palladino, E

    2003-01-01

    An efficient sky data reconstruction derives from a precise characterization of the observing instrument. Here we describe the reconstruction of performances of a single-pixel 4-band photometer installed at MITO (Millimeter and Infrared Testagrigia Observatory) focal plane. The strategy of differential sky observations at millimeter wavelengths, by scanning the field of view at constant elevation wobbling the subreflector, induces a good knowledge of beam profile and beam-throw amplitude, allowing efficient data recovery. The problems that arise estimating the detectors throughput by drift scanning on planets are shown. Atmospheric transmission, monitored by skydip technique, is considered for deriving final responsivities for the 4 channels using planets as primary calibrators.

  9. Precipitation and microphysical processes observed by three polarimetric X-band radars and ground-based instrumentation during HOPE

    Science.gov (United States)

    Xie, Xinxin; Evaristo, Raquel; Simmer, Clemens; Handwerker, Jan; Trömel, Silke

    2016-06-01

    This study presents a first analysis of precipitation and related microphysical processes observed by three polarimetric X-band Doppler radars (BoXPol, JuXPol and KiXPol) in conjunction with a ground-based network of disdrometers, rain gauges and vertically pointing micro rain radars (MRRs) during the High Definition Clouds and Precipitation for advancing Climate Prediction (HD(CP)2) Observational Prototype Experiment (HOPE) during April and May 2013 in Germany. While JuXPol and KiXPol were continuously observing the central HOPE area near Forschungszentrum Jülich at a close distance, BoXPol observed the area from a distance of about 48.5 km. MRRs were deployed in the central HOPE area and one MRR close to BoXPol in Bonn, Germany. Seven disdrometers and three rain gauges providing point precipitation observations were deployed at five locations within a 5 km × 5 km region, while three other disdrometers were collocated with the MRR in Bonn. The daily rainfall accumulation at each rain gauge/disdrometer location estimated from the three X-band polarimetric radar observations showed very good agreement. Accompanying microphysical processes during the evolution of precipitation systems were well captured by the polarimetric X-band radars and corroborated by independent observations from the other ground-based instruments.

  10. The Gaia spectrophotometric standard stars survey -II. Instrumental effects of six ground-based observing campaigns

    CERN Document Server

    Altavilla, G; Pancino, E; Galleti, S; Ragaini, S; Bellazzini, M; Cocozza, G; Bragaglia, A; Carrasco, J M; Castro, A; Di Fabrizio, L; Federici, L; Figueras, F; Gebran, M; Jordi, C; Masana, E; Schuster, W; Valentini, G; Voss, H

    2015-01-01

    The Gaia SpectroPhotometric Standard Stars (SPSS) survey started in 2006, it was awarded almost 450 observing nights, and accumulated almost 100,000 raw data frames, with both photometric and spectroscopic observations. Such large observational effort requires careful, homogeneous, and automated data reduction and quality control procedures. In this paper, we quantitatively evaluate instrumental effects that might have a significant (i.e.,$\\geq$1%) impact on the Gaia SPSS flux calibration. The measurements involve six different instruments, monitored over the eight years of observations dedicated to the Gaia flux standards campaigns: DOLORES@TNG in La Palma, EFOSC2@NTT and ROSS@REM in La Silla, CAFOS@2.2m in Calar Alto, BFOSC@Cassini in Loiano, and LaRuca@1.5m in San Pedro Martir. We examine and quantitatively evaluate the following effects: CCD linearity and shutter times, calibration frames stability, lamp flexures, second order contamination, light polarization, and fringing. We present methods to correct ...

  11. Instrumentation for Ground-Based Testing in Simulated Space and Planetary Conditions

    Science.gov (United States)

    Kleiman, Jacob; Horodetsky, Sergey; Issoupov, Vitali

    This paper is an overview of instrumentation developed and created by ITL Inc. for simulated testing and performance evaluation of spacecraft materials, structures, mechanisms, assemblies and components in different space and planetary environments. The LEO Space Environment Simulator allows simulation of the synergistic effect of ultra-high vacuum conditions, 5 eV neutral atomic oxygen beams, Vacuum-Ultraviolet (VUV) and Near-Ultraviolet (NUV) radiation, and temperature conditions. The simulated space environmental conditions can be controlled in-situ using a quadruple mass-spectrometer, Time-of-Flight technique, as well as Quartz Crystal Microbalance sensors. The new NUV System is capable of delivering an NUV power intensity of up to 10 Equivalent Suns. The design of the system uses horizontal orientation of the 5 kW Mercury lamp, focusing of NUV radiation is achieved due to a parabolic reflector. To address the Lunar/Martian surface environments, the Planetary Environmental Simulator/Test Facility has been developed and built to allow for physical evaluation of the effects of the Lunar/Martian dust environments in conjunction with other factors (ultra-high vacuum or planetary atmospheric conditions, VUV/NUV radiation, thermal cycling, and darkness). The ASTM E 595/ASTM E 1559 Outgassing Test Facility provides the means for the outgassing test of materials with the objective to select materials with low outgassing properties for spacecraft use and allows to determine the following outgassing parameters: Total Mass Loss, Collected Volatile Condensable Materials, and Water Vapor Regained.

  12. The CU Airborne MAX-DOAS instrument: ground based validation, and vertical profiling of aerosol extinction and trace gases

    Directory of Open Access Journals (Sweden)

    S. Baidar

    2012-09-01

    Full Text Available The University of Colorado Airborne Multi Axis Differential Optical Absorption Spectroscopy (CU AMAX-DOAS instrument uses solar stray light remote sensing to detect and quantify multiple trace gases, including nitrogen dioxide (NO2, glyoxal (CHOCHO, formaldehyde (HCHO, water vapor (H2O, nitrous acid (HONO, iodine monoxide (IO, bromine monoxide (BrO, and oxygen dimers (O4 at multiple wavelengths (360 nm, 477 nm, 577 nm and 632 nm simultaneously, and sensitively in the open atmosphere. The instrument is unique, in that it presents the first systematic implementation of MAX-DOAS on research aircraft, i.e. (1 includes measurements of solar stray light photons from nadir, zenith, and multiple elevation angles forward and below the plane by the same spectrometer/detector system, and (2 features a motion compensation system that decouples the telescope field of view (FOV from aircraft movements in real-time (< 0.35° accuracy. Sets of solar stray light spectra collected from nadir to zenith scans provide some vertical profile information within 2 km above and below the aircraft altitude, and the vertical column density (VCD below the aircraft is measured in nadir view. Maximum information about vertical profiles is derived simultaneously for trace gas concentrations and aerosol extinction coefficients over similar spatial scales and with a vertical resolution of typically 250 m during aircraft ascent/descent.

    The instrument is described, and data from flights over California during the CalNex and CARES air quality field campaigns is presented. Horizontal distributions of NO2 VCDs (below the aircraft maps are sampled with typically 1 km resolution, and show good agreement with two ground based CU MAX-DOAS instruments (slope 0.95 ± 0.09, R2 = 0.86. As a case study vertical profiles of NO2, CHOCHO, HCHO, and H2O mixing ratios and aerosol extinction coefficients

  13. Ozone columns obtained by ground-based remote sensing in Kiev for Aura Ozone Measuring Instrument validation

    Science.gov (United States)

    Shavrina, A. V.; Pavlenko, Y. V.; Veles, A.; Syniavskyi, I.; Kroon, M.

    2007-12-01

    Ground-based observations with a Fourier transform spectrometer in the infrared region (FTIR) were performed in Kiev (Ukraine) during the time frames August-October 2005 and June-October 2006 within the Ozone Monitoring Instrument (OMI) validation project 2907 entitled "OMI validation by ground based remote sensing: ozone columns and profiles" in the frame of the international European Space Agency/Netherlands Agency for Aerospace Programmes/Royal Dutch Meteorological Institute OMI Announcement of Opportunity effort. Ozone column data for 2005 were obtained by modeling the ozone spectral band at 9.6 μm with the radiative transfer code MODTRAN3.5. Our total ozone column values were found to be lower than OMI Differential Optical Absorption Spectroscopy (DOAS) total ozone column data by 8-10 Dobson units (DU, 1 DU = 0.001 atm cm) on average, while our observations have a relatively small standard error of about 2 DU. Improved modeling of the ozone spectral band, now based on HITRAN-2004 spectral data as calculated by us, moves our results toward better agreement with the OMI DOAS total ozone column data. The observations made during 2006 with a modernized FTIR spectrometer and higher signal-to-noise ratio were simulated by the MODTRAN4 model computations. For ozone column estimates the Aqua Atmospheric Infrared Sounder satellite water vapor and temperature profiles were combined with the Aura Microwave Limb Sounder stratospheric ozone profiles and Tropospheric Emission Monitoring Internet Service-Koninklijk Nederlands Meteorologisch Instituut climatological profiles to create a priori input files for spectral modeling. The MODTRAN4 estimates of ozone columns from the 2006 observations compare rather well with the OMI total ozone column data: standard errors are of 1.11 DU and 0.68 DU, standard deviation are of 8.77 DU and 5.37 DU for OMI DOAS and OMI Total Ozone Mapping Spectrometer, respectively.

  14. The CU Airborne MAX-DOAS instrument: ground based validation, and vertical profiling of aerosol extinction and trace gases

    Science.gov (United States)

    Baidar, S.; Oetjen, H.; Coburn, S.; Dix, B.; Ortega, I.; Sinreich, R.; Volkamer, R.

    2012-09-01

    The University of Colorado Airborne Multi Axis Differential Optical Absorption Spectroscopy (CU AMAX-DOAS) instrument uses solar stray light remote sensing to detect and quantify multiple trace gases, including nitrogen dioxide (NO2), glyoxal (CHOCHO), formaldehyde (HCHO), water vapor (H2O), nitrous acid (HONO), iodine monoxide (IO), bromine monoxide (BrO), and oxygen dimers (O4) at multiple wavelengths (360 nm, 477 nm, 577 nm and 632 nm) simultaneously, and sensitively in the open atmosphere. The instrument is unique, in that it presents the first systematic implementation of MAX-DOAS on research aircraft, i.e. (1) includes measurements of solar stray light photons from nadir, zenith, and multiple elevation angles forward and below the plane by the same spectrometer/detector system, and (2) features a motion compensation system that decouples the telescope field of view (FOV) from aircraft movements in real-time (CHOCHO, HCHO, and H2O mixing ratios and aerosol extinction coefficients, ɛ, at 477nm calculated from O4 measurements from a low approach at Brackett airfield inside the South Coast Air Basin (SCAB) are presented. These profiles contain ~ 12 degrees of freedom (DOF) over a 3.5 km altitude range, independent of signal-to-noise at which the trace gas is detected. The boundary layer NO2 concentration, and the integral aerosol extinction over height (aerosol optical depth, AOD) agrees well with nearby ground-based in-situ NO2 measurement, and AERONET station. The detection limits of NO2, CHOCHO, HCHO, ɛ360, ɛ477 from 30 s integration time spectra recorded forward of the plane are 5 ppt, 3 ppt, 100 ppt, 0.004 km-1, 0.002 km-1 in the free troposphere (FT), and 30 ppt, 16 ppt, 540 ppt, 0.012 km-1, 0.006 km-1 inside the boundary layer (BL), respectively. Mobile column observations of trace gases and aerosols are complimentary to in-situ observations, and help bridge the spatial scales probed by ground-based observations, satellites, and predicted by atmospheric

  15. Conjugate observations of a remarkable quasiperiodic event by the low-altitude DEMETER spacecraft and ground-based instruments

    Science.gov (United States)

    Němec, F.; Bezděková, B.; Manninen, J.; Parrot, M.; Santolík, O.; Hayosh, M.; Turunen, T.

    2016-09-01

    We present a detailed analysis of a long-lasting quasiperiodic (QP) event observed simultaneously by the low-altitude DEMETER spacecraft and on the ground by the instrumentation of the Sodankylä Geophysical Observatory, Finland. The event was observed on 26 February 2008. It lasted for several hours, and it was detected both in the Northern and Southern Hemispheres. The time intervals when the event was observed on board the satellite and/or on the ground provide us with an estimate of the event dimensions. When the event is detected simultaneously by the satellite and on the ground, the observed frequency-time structure is generally the same. However, the ratio of detected intensities varies significantly as a function of the spacecraft latitude, indicating the wave guiding along the plasmapause. Moreover, there is a delay as large as about 13 s between the times when individual QP elements are detected by the spacecraft and on the ground. This appears to be related to the azimuthal separation of the instruments, and it is highly relevant to the identification of a possible source mechanism. We suggest that it is due to an azimuthally propagating ULF wave which periodically modulates the azimuthally extended source region. Finally, we find that at the times when the intensity of the QP event suddenly increases, there is a distinct increase of the amplitude of Alfvénic ULF pulsations measured on the ground at high latitudes. This might indicate that the source region is located at L shells larger than about 7.1.

  16. Validation of satellite-based noontime UVI with NDACC ground-based instruments: influence of topography, environment and satellite overpass time

    Science.gov (United States)

    Brogniez, Colette; Auriol, Frédérique; Deroo, Christine; Arola, Antti; Kujanpää, Jukka; Sauvage, Béatrice; Kalakoski, Niilo; Riku Aleksi Pitkänen, Mikko; Catalfamo, Maxime; Metzger, Jean-Marc; Tournois, Guy; Da Conceicao, Pierre

    2016-12-01

    Spectral solar UV radiation measurements are performed in France using three spectroradiometers located at very different sites. One is installed in Villeneuve d'Ascq, in the north of France (VDA). It is an urban site in a topographically flat region. Another instrument is installed in Observatoire de Haute-Provence, located in the southern French Alps (OHP). It is a rural mountainous site. The third instrument is installed in Saint-Denis, Réunion Island (SDR). It is a coastal urban site on a small mountainous island in the southern tropics. The three instruments are affiliated with the Network for the Detection of Atmospheric Composition Change (NDACC) and carry out routine measurements to monitor the spectral solar UV radiation and enable derivation of UV index (UVI). The ground-based UVI values observed at solar noon are compared to similar quantities derived from the Ozone Monitoring Instrument (OMI, onboard the Aura satellite) and the second Global Ozone Monitoring Experiment (GOME-2, onboard the Metop-A satellite) measurements for validation of these satellite-based products. The present study concerns the period 2009-September 2012, date of the implementation of a new OMI processing tool. The new version (v1.3) introduces a correction for absorbing aerosols that were not considered in the old version (v1.2). Both versions of the OMI UVI products were available before September 2012 and are used to assess the improvement of the new processing tool. On average, estimates from satellite instruments always overestimate surface UVI at solar noon. Under cloudless conditions, the satellite-derived estimates of UVI compare satisfactorily with ground-based data: the median relative bias is less than 8 % at VDA and 4 % at SDR for both OMI v1.3 and GOME-2, and about 6 % for OMI v1.3 and 2 % for GOME-2 at OHP. The correlation between satellite-based and ground-based data is better at VDA and OHP (about 0.99) than at SDR (0.96) for both space-borne instruments. For all

  17. Comparison of ground-based FTIR and Brewer O3 total column with data from two different IASI algorithms and from OMI and GOME-2 satellite instruments

    OpenAIRE

    Blumenstock, T.; J.-M. Flaud; P. Chelin; Eremenko, M.; A. Redondas; Hase, F.; Schneider, M; C. Viatte; Orphal, J

    2011-01-01

    An intercomparison of ozone total column measurements derived from various platforms is presented in this work. Satellite data from Infrared Atmospheric Sounding Interferometer (IASI), Ozone Monitoring Instrument (OMI) and Global Ozone Monitoring Experiment (GOME-2) are compared with data from two ground-based spectrometers (Fourier Transform Infrared spectrometer FTIR and Brewer), located at the Network for Detection of Atmospheric Composition Change (NDACC) super-site of Izaña (Tenerife), m...

  18. Precipitation and microphysical processes observed by three polarimetric X-band radars and ground-based instrumentation during HOPE

    OpenAIRE

    Xie, Xinxin; Evaristo, Raquel; Simmer, Clemens; Handwerker, Jan; Trömel, Silke

    2016-01-01

    This study presents a first analysis of precipitation and related microphysical processes observed by three polarimetric X-band Doppler radars (BoXPol, JuXPol and KiXPol) in conjunction with a ground-based network of disdrometers, rain gauges and vertically pointing micro rain radars (MRRs) during the High Definition Clouds and Precipitation for advancing Climate Prediction (HD(CP)2) Observational Prototype Experiment (HOPE) during April and May 2013 in Germany. While JuXPol...

  19. Westward moving dynamic substorm features observed with the IMAGE magnetometer network and other ground-based instruments

    Directory of Open Access Journals (Sweden)

    H. Lühr

    Full Text Available We present the ground signatures of dynamic substorm features with particular emphasis on the event interpretation capabilities provided by the IMAGE magnetometer network. This array covers the high latitudes from the sub-auroral to the cusp/cleft region. An isolated substorm on 11 Oct. 1993 during the late evening hours exhibited many of well-known features such as the Harang discontinuity, westward travelling surge and poleward leap, but also discrete auroral forms, known as auroral streamers, appeared propagating westward along the centre of the electrojet. Besides the magnetic field measurements, there were auroral observations and plasma flow and conductivity measurements obtained by EISCAT. The data of all three sets of instruments are consistent with the notion of upward field-aligned currents associated with the moving auroral patches. A detailed analysis of the electrodynamic parameters in the ionosphere, however, reveals that they do not agree with the expectations resulting from commonly used simplifying approximations. For example, the westward moving auroral streamers which are associated with field-aligned current filaments, are not collocated with the centres of equivalent current vortices. Furthermore, there is a clear discrepancy between the measured plasma flow direction and the obtained equivalent current direction. All this suggests that steep conductivity gradients are associated with the transient auroral forms. Also self-induction effects in the ionosphere may play a role for the orientation of the plasma flows. This study stresses the importance of multi-instrument observation for a reliable interpretation of dynamic auroral processes.

    Keywords. Ionosphere (Auroral ionosphere; Electric fields and currents; Ionosphere-magnetosphere interactions.

  20. Intercomparison of stratospheric nitrogen dioxide columns retrieved from ground-based DOAS and FTIR and satellite DOAS instruments over the subtropical Izana station

    Science.gov (United States)

    Robles-Gonzalez, Cristina; Navarro-Comas, Mónica; Puentedura, Olga; Schneider, Matthias; Hase, Frank; Garcia, Omaira; Blumenstock, Thomas; Gil-Ojeda, Manuel

    2016-09-01

    A 13-year analysis (2000-2012) of the NO2 vertical column densities derived from ground-based (GB) instruments and satellites has been carried out over the Izaña NDACC (Network for the Detection of the Atmospheric Composition Change) subtropical site. Ground-based DOAS (differential optical absorption spectroscopy) and FTIR (Fourier transform infrared spectroscopy) instruments are intercompared to test mutual consistency and then used for validation of stratospheric NO2 from OMI (Ozone Monitoring Instrument) and SCIAMACHY (SCanning Imaging Absorption spectroMeter for Atmospheric CHartographY). The intercomparison has been carried out taking into account the various differences existing in instruments, namely temporal coincidence, collocation, sensitivity, field of view, etc. The paper highlights the importance of considering an "effective solar zenith angle" instead of the actual one when comparing direct-sun instruments with zenith sky ones for a proper photochemical correction. Results show that NO2 vertical column densities mean relative difference between FTIR and DOAS instruments is 2.8 ± 10.7 % for a.m. data. Both instruments properly reproduce the NO2 seasonal and the interannual variation. Mean relative difference of the stratospheric NO2 derived from OMI and DOAS is -0.2 ± 8.7 % and from OMI and FTIR is -1.6 ± 6.7 %. SCIAMACHY mean relative difference is of 3.7 ± 11.7 and -5.7 ± 11.0 % for DOAS and FTIR, respectively. Note that the days used for the intercomparison are not the same for all the pairs of instruments since it depends on the availability of data. The discrepancies are found to be seasonally dependent with largest differences in winter and excellent agreement in the spring months (AMJ). A preliminary analysis of NO2 trends has been carried out with the available data series. Results show increases in stratospheric NO2 columns in all instruments but larger values in those that are GB than that expected by nitrous oxide oxidation. The

  1. Comparison of ground-based FTIR and Brewer O3 total column with data from two different IASI algorithms and from OMI and GOME-2 satellite instruments

    Directory of Open Access Journals (Sweden)

    T. Blumenstock

    2011-03-01

    Full Text Available An intercomparison of ozone total column measurements derived from various platforms is presented in this work. Satellite data from Infrared Atmospheric Sounding Interferometer (IASI, Ozone Monitoring Instrument (OMI and Global Ozone Monitoring Experiment (GOME-2 are compared with data from two ground-based spectrometers (Fourier Transform Infrared spectrometer FTIR and Brewer, located at the Network for Detection of Atmospheric Composition Change (NDACC super-site of Izaña (Tenerife, measured during a campaign from March to June 2009. These ground-based observing systems have already been demonstrated to perform consistent, precise and accurate ozone total column measurements. An excellent agreement between ground-based and OMI/GOME-2 data is observed. Results from two different algorithms for deriving IASI ozone total column are also compared: the European Organisation for the Exploitation of Meteorological Satellites (EUMETSAT/ESA operational algorithm and the LISA (Laboratoire Inter-universitaire des Systèmes Atmosphériques algorithm. A better agreement was found with LISA's analytical approach based on an altitude-dependent Tikhonov-Philips regularization: correlations are 0.94 and 0.89 compared to FTIR and Brewer, respectively; while the operational IASI ozone columns (based on neural network analysis show correlations of 0.90 and 0.85, respectively, compared to the O3 columns obtained from FTIR and Brewer.

  2. Ground-based instrumentation for measurements of atmospheric conduction current and electric field at the South Pole

    Science.gov (United States)

    Byrne, G. J.; Benbrook, J. R.; Bering, E. A.; Few, A. A.; Morris, G. A.; Trabucco, W. J.; Paschal, E. W.

    1993-01-01

    Attention is given to instruments constructed to measure the atmospheric conduction current and the atmospheric electric field - two fundamental parameters of the global-electric circuit. The instruments were deployed at the Amundsen-Scott South Pole Station in January 1991 and are designed to operate continuously for up to one year without operator intervention. The atmospheric current flows into one hemisphere, through the electronics where it is measured, and out the other hemisphere. The electric field is measured by a field mill of the rotating dipole type. Sample data from the first days of operation at the South Pole indicate variations in the global circuit over time scales from minutes to hours to days.

  3. CO measurements from the ACE-FTS satellite instrument: data analysis and validation using ground-based, airborne and spaceborne observations

    Directory of Open Access Journals (Sweden)

    C. Clerbaux

    2007-10-01

    Full Text Available The Atmospheric Chemistry Experiment (ACE mission was launched in August 2003 to sound the atmosphere by solar occultation. Carbon monoxide (CO, a good tracer of pollution plumes and atmospheric dynamics, is one of the key species provided by the primary instrument, the ACE-Fourier Transform Spectrometer (ACE-FTS. This instrument performs measurements in both the CO 1-0 and 2-0 ro-vibrational bands, from which vertically resolved CO concentration profiles are retrieved, from the mid-troposphere to the thermosphere. This paper presents an updated description of the ACE-FTS version 2.2 CO data product, along with a comprehensive validation of these profiles using available observations (February 2004 to December 2006. We have compared the CO partial columns with ground-based measurements using Fourier transform infrared spectroscopy and millimeter wave radiometry, and the volume mixing ratio profiles with airborne (both high-altitude balloon flight and airplane observations. CO satellite observations provided by nadir-looking instruments (MOPITT and TES as well as limb-viewing remote sensors (MIPAS, SMR and MLS were also compared with the ACE-FTS CO products. We show that the ACE-FTS measurements provide CO profiles with small retrieval errors (better than 5% from the upper troposphere to 40 km, and better than 10% above. These observations agree well with the correlative measurements, considering the rather loose coincidence criteria in some cases. Based on the validation exercise we assess the following uncertainties to the ACE-FTS measurement data: better than 15% in the upper troposphere (8–12 km, than 30% in the lower stratosphere (12–30 km, and than 25% from 30 to 100 km.

  4. CO measurements from the ACE-FTS satellite instrument: data analysis and validation using ground-based, airborne and spaceborne observations

    Directory of Open Access Journals (Sweden)

    C. Clerbaux

    2008-05-01

    Full Text Available The Atmospheric Chemistry Experiment (ACE mission was launched in August 2003 to sound the atmosphere by solar occultation. Carbon monoxide (CO, a good tracer of pollution plumes and atmospheric dynamics, is one of the key species provided by the primary instrument, the ACE-Fourier Transform Spectrometer (ACE-FTS. This instrument performs measurements in both the CO 1-0 and 2-0 ro-vibrational bands, from which vertically resolved CO concentration profiles are retrieved, from the mid-troposphere to the thermosphere. This paper presents an updated description of the ACE-FTS version 2.2 CO data product, along with a comprehensive validation of these profiles using available observations (February 2004 to December 2006. We have compared the CO partial columns with ground-based measurements using Fourier transform infrared spectroscopy and millimeter wave radiometry, and the volume mixing ratio profiles with airborne (both high-altitude balloon flight and airplane observations. CO satellite observations provided by nadir-looking instruments (MOPITT and TES as well as limb-viewing remote sensors (MIPAS, SMR and MLS were also compared with the ACE-FTS CO products. We show that the ACE-FTS measurements provide CO profiles with small retrieval errors (better than 5% from the upper troposphere to 40 km, and better than 10% above. These observations agree well with the correlative measurements, considering the rather loose coincidence criteria in some cases. Based on the validation exercise we assess the following uncertainties to the ACE-FTS measurement data: better than 15% in the upper troposphere (8–12 km, than 30% in the lower stratosphere (12–30 km, and than 25% from 30 to 100 km.

  5. Ground-based Magnetometer Array Science for IHY: Opportunities for an Array in Africa within the UNBSS Developing Nations Small Instrument Program

    Science.gov (United States)

    Mann, I. R.; Milling, D. K.; Moldwin, M.; Yizengaw, E.

    2005-12-01

    Arrays of ground-based magnetometers provide the capability for the meso- and global-scale monitoring of current systems and waves in the coupled magnetosphere-ionosphere system. Recent advances in the processing of multiple time series magnetometer array data allows the inversion of standing Alfven eigenfrequencies for the purposes of monitoring density depletion and refilling dynamics in the plasmasphere, plasmapause and plasmatrough regions. In addition, mid-latitude magnetometer arrays can also allow the monitoring of the ULF waves which are implicated in the transport and acceleration of MeV energy electrons in the radiation belts, as well as monitoring the penetration of asymmetric ring current and substorm current systems to mid- and low-latitudes during storms. Fluxgate magnetometer technology is relatively inexpensive, and the data sets are small allowing relatively easy collection of data through the low-band-width internet connections. However, the accumulation of magnetometer data into nation-, continental- and global-scale array coverage provides a powerful tool for pursuing IHY science objectives. We present examples of how these concepts might be exploited through the UN Developing Nations Small Instrument program with the creation, coordination and operation of an IHY Magnetometer Array (IHYMag). The IHY science focus on storms also ensures that mid-latitude and even equatorial developing nations coverage would ensure IHYMag data is a valuable resource for IHY scientists. African locations offer a prime opportunity to expand the global magnetometer coverage into this region during IHY. Technology being developed for instrument development and data collection for the CARISMA formerly CANOPUS) magnetometer array expansion, including planned use of solar and/or wind turbine power at the remote BACK magnetometer site in the CARISMA array, might also form a basis for the hardware development which could be used to support a Developing Nations Small

  6. Technical Note: Validation of Odin/SMR limb observations of ozone, comparisons with OSIRIS, POAM III, ground-based and balloon-borne instruments

    Directory of Open Access Journals (Sweden)

    F. Jégou

    2008-01-01

    Full Text Available The Odin satellite carries two instruments capable of determining stratospheric ozone profiles by limb sounding: the Sub-Millimetre Radiometer (SMR and the UV-visible spectrograph of the OSIRIS (Optical Spectrograph and InfraRed Imager System instrument. A large number of ozone profiles measurements were performed during six years from November 2001 to present. This ozone dataset is here used to make quantitative comparisons with satellite measurements in order to assess the quality of the Odin/SMR ozone measurements. In a first step, we compare Swedish SMR retrievals version 2.1, French SMR ozone retrievals version 222 (both from the 501.8 GHz band, and the OSIRIS retrievals version 3.0, with the operational version 4.0 ozone product from POAM III (Polar Ozone Atmospheric Measurement. In a second step, we refine the Odin/SMR validation by comparisons with ground-based instruments and balloon-borne observations. We use observations carried out within the framework of the Network for Detection of Atmospheric Composition Change (NDACC and balloon flight missions conducted by the Canadian Space Agency (CSA, the Laboratoire de Physique et de Chimie de l'Environnement (LPCE, Orléans, France, and the Service d'Aéronomie (SA, Paris, France. Coincidence criteria were 5° in latitude x in 10° longitude, and 5 h in time in Odin/POAM III comparisons, 12 h in Odin/NDACC comparisons, and 72 h in Odin/balloons comparisons. An agreement is found with the POAM III experiment (10–60 km within −0.3±0.2 ppmv (bias±standard deviation for SMR (v222, v2.1 and within −0.5±0.2 ppmv for OSIRIS (v3.0. Odin ozone mixing ratio products are systematically slightly lower than the POAM III data and show an ozone maximum lower by 1–5 km in altitude. The comparisons with the NDACC data (10–34 km for ozonesonde, 10–50 km for lidar, 10–60 for microwave instruments yield a good agreement within −0.15±0.3 ppmv for the SMR data and −0.3±0.3 ppmv

  7. Technical note: Sensitivity of instrumental line shape monitoring for the ground-based high-resolution FTIR spectrometer with respect to different optical attenuators

    Science.gov (United States)

    Sun, Youwen; Palm, Mathias; Weinzierl, Christine; Petri, Christof; Notholt, Justus; Wang, Yuting; Liu, Cheng

    2017-03-01

    The TCCON (Total Carbon Column Observing Network) and most NDACC (Network for Detection of Atmospheric Composition Change) sites assume an ideal ILS (instrumental line shape) for analysis of the spectra. In order to adapt the radiant energy received by the detector, an attenuator or different sizes of field stop can be inserted in the light path. These processes may alter the alignment of a high-resolution FTIR (Fourier transform infrared) spectrometer, and may result in bias due to ILS drift. In this paper, we first investigated the sensitivity of the ILS monitoring with respect to application of different kinds of attenuators for ground-based high-resolution FTIR spectrometers within the TCCON and NDACC networks. Both lamp and sun cell measurements were conducted after the insertion of five different attenuators in front of and behind the interferometer. The ILS characteristics derived from lamp and sun spectra are in good agreement. ILSs deduced from all lamp cell measurements were compared. As a result, the disturbances to the ILS of a high-resolution FTIR spectrometer with respect to the insertion of different attenuators at different positions were quantified. A potential strategy to adapt the incident intensity of a detector was finally deduced.

  8. Improved instrumental line shape monitoring for the ground-based, high-resolution FTIR spectrometers of the Network for the Detection of Atmospheric Composition Change

    Directory of Open Access Journals (Sweden)

    F. Hase

    2012-03-01

    Full Text Available We propose an improved monitoring scheme for the instrumental line shape (ILS of high-resolution, ground-based FTIR (Fourier Transform InfraRed spectrometers used for chemical monitoring of the atmosphere by the Network for Detection of Atmospheric Composition Change (NDACC. Good ILS knowledge is required for the analysis of the recorded mid-infrared spectra. The new method applies a sequence of measurements using different gas cells instead of a single calibration cell. Three cells are used: cell C1 is a refillable cell offering 200 mm path length and equipped with a pressure gauge (filled with 100 Pa N2O, cells C2 and C3 are sealed cells offering 75 mm path length. C2 is filled with 5 Pa of pure N2O. Cell C3 is filled with 16 Pa N2O in 200 hPa technical air, so provides pressure-broadened N2O lines. We demonstrate that an ILS retrieval using C1 improves significantly the sensitivity of the ILS retrieval over the current calibration cells used in the network, because this cell provides narrow fully saturated N2O lines. The N2O columns derived from C2 and C3 allow the performance of a highly valuable closure experiment: adopting the ILS retrieved from C1, the N2O columns of C2 and C3 are derived. Because N2O is an inert gas, both columns should be constant on long timescales. Apparent changes in the columns would immediately attract attention and indicate either inconsistent ILS results or instrumental problems of other origin. Two different cells are applied for the closure experiment, because the NDACC spectrometers observe both stratospheric and tropospheric gases: C2 mimics signatures of stratospheric gases, whereas C3 mimics signatures of tropospheric gases.

  9. A case study of pollutants transported from HPCL (vishakhapatnam) accidental fire through synergy of flexpart model and ground-based instruments

    Science.gov (United States)

    Wankhede, Tushar

    Tushar Wankhede*, Harish Gadhavi, Amit K. Pandit National Atmospheric Research Laboratory (NARL), Gadanki-517112, Chittoor, A.P. *tushar1771@gmail.com, Mobile: +91-8297152481 A fire at Hindustan Petroleum Corporation Limited (HPCL) in Vishakhapatnam (17.70 ˚N, 83.24˚E) resulted from a gas leak in the salt water cooling tower system. This led to the release of various pollutants like hydrocarbons, black carbon, carbon mono-oxide and carbon dioxide etc(other gases) in just 44 min of fire in system a very huge amount of particles were emitted. The transport of these pollutants has been studied through FLEXPART which is a Lagrangian particle dispersion model having wide range of applications in atmospheric transport modeling. FLEXPART simulation of this accidental fire shows the direction and sensitivity of dispersed pollutants from its source. It was observed that the pollutants reached Gadanki, a rural site located at 13.45 ˚N, 79.18 ˚E in Southern-India. The concentration of pollutant obtained from FLEXPART output we are comparing with ground based instruments data collected at the observation site (Indian Climate Observatory Network-ICON, NARL Gadanki). This case-study provides significant information about the life-time of dispersed pollutants and their long-range transport pattern under the influence of small weather variability en-route from source to receptor. The detailed work of FLEXPART for the Long range transport of the particles will be presented later on in conference.

  10. HOLIMO II: a digital holographic instrument for ground-based in-situ observations of microphysical properties of mixed-phase clouds

    Directory of Open Access Journals (Sweden)

    J. Henneberger

    2013-05-01

    Full Text Available Measurements of the microphysical properties of mixed-phase clouds with high spatial resolution are important to understand the processes inside these clouds. This work describes the design and characterization of the newly developed ground-based field instrument HOLIMO II (HOLographic Imager for Microscopic Objects II. HOLIMO II uses digital in-line holography to in-situ image cloud particles in a well defined sample volume. By an automated algorithm, two-dimensional images of single cloud particles between 6 and 250 μm in diameter are obtained and the size spectrum, the concentration and water content of clouds are calculated. By testing the sizing algorithm with monosized beads a systematic overestimation near the resolution limit was found, which has been used to correct the measurements. Field measurements from the high altitude research station Jungfraujoch, Switzerland, are presented. The measured number size distributions are in good agreement with parallel measurements by a fog monitor (FM-100, DMT, Boulder USA. The field data shows that HOLIMO II is capable of measuring the number size distribution with a high spatial resolution and determines ice crystal shape, thus providing a method of quantifying variations in microphysical properties. A case study over a period of 8 h has been analyzed, exploring the transition from a liquid to a mixed-phase cloud, which is the longest observation of a cloud with a holographic device. During the measurement period, the cloud does not completely glaciate, contradicting earlier assumptions of the dominance of the Wegener–Bergeron–Findeisen (WBF process.

  11. Ground-based water vapor Raman lidar measurements up to the upper troposphere and lower stratosphere – Part 1: Instrument development, optimization, and validation

    Directory of Open Access Journals (Sweden)

    I. S. McDermid

    2011-08-01

    Full Text Available Recognizing the importance of water vapor in the upper troposphere and lower stratosphere (UT/LS and the scarcity of high-quality, long-term measurements, JPL began the development of a powerful Raman lidar in 2005 to try to meet these needs. This development was endorsed by the Network for the Detection of Atmospheric Composition Change (NDACC and the validation program for the EOS-Aura satellite. In this paper we review the stages in the instrumental development of the lidar and the conclusions from three validation campaigns: MOHAVE, MOHAVE-II, and MOHAVE 2009 (Measurements of Humidity in the Atmosphere and Validation Experiments. The data analysis, profile retrieval and calibration procedures, as well as additional results from MOHAVE-2009 are presented in detail in a companion paper (Leblanc et al., 2011a. Ultimately the lidar has demonstrated capability to measure water vapor profiles from ~1 km above the ground to the lower stratosphere, reaching 14 km for 1-h integrated profiles and 21 km for 6-h integrated profiles, with a precision of 10 % or better near 13 km and below, and an estimated accuracy of 5 %.

  12. Atmospheric turbulence measurements over desert site using ground-based instruments, kite/tethered-blimp platform, and aircraft relevant to optical communications and imaging systems: preliminary results

    Science.gov (United States)

    Majumdar, Arun K.; Eaton, Frank D.; Jensen, Michael L.; Kyrazis, Demos T.; Schumm, Bryce; Dierking, Matthew P.; Shoemake, Marjorie A.; Dexheimer, Dari; Ricklin, Jennifer C.

    2006-08-01

    New results of the (temperature) refractive index structure parameter (C T2), C n2 are presented from fast response sensor observations near the ground and also using a kite/tethered blimp platform and an aircraft, at the Edward Air Force Base in Mojave Desert, California. Additional optical measurements include near-ground scintillation observations over horizontal paths. Atmospheric turbidity were also calculated from direct beam solar radiation measurements using pyrheliometer. Comparisons were made of the observed profiles of refractive index structure parameters (C n2) with theoretical modeled profiles, and two derived quantities such as transverse coherence length (r 0) and isoplanatic angle (θ 0) for a slant path are discussed. All of these parameters are the major indicators of turbulence and are important to design an aircraft or space-craft-based free-space laser communication and high resolution optical synthetic-aperture imaging systems. Non-isotropic turbulence observations from some of the data will be pointed out. Probability density functions (PDF) of the distribution of C n2 will be described using histograms. Fundamental limits imposed by atmospheric effects in high data rate communication and optical synthetic-aperture imaging systems will be discussed.

  13. Observations of UV radiation and total ozone column using ground based instruments in Río Gallegos, Argentina (51° 36' S, 69° 19' W)

    Science.gov (United States)

    Salvador, Jacobo; Wolfram, Elian; Orte, Facundo; D'Elia, Raul; Bulnes, Daniela; Quel, Eduardo

    2013-05-01

    As a part of environmental studies in the southern hemisphere, the CEILAP Lidar Division with the financial support of JICA (Japan International Cooperation Agency) and the collaboration of IPSL France, mounted a ground based remote sensing site at Río Gallegos city (51° 36'S, 69° 19'W), at southern part of South America for the measurements of stratospheric ozone, with lidar remote sensing techniques and passive sensors to measure solar UV irradiance. The Patagonian region is characterized by high cloud cover during day changing strongly the distribution of UV radiation that reaches the ground surface. During the spring season some overpasses of ozone hole are masked by cloud cover avoiding the increase in UVB radiation. Solar UV radiation measured with multiband filter radiometer GUV-541 and Biometer manufactured by Biospherial Inc. San Diego and the Yankee Environmental Systems (YES) companies respectively. We present nine study days in the period 2007-2011 where total ozone column was below 250 DU focusing the impact that cloud cover had on the temporal evolution of these events.

  14. Cross-validation of two liquid water path retrieval algorithms applied to ground-based microwave radiation measurements by RPG-HATPRO instrument

    Science.gov (United States)

    Kostsov, Vladimir; Ionov, Dmitry; Biryukov, Egor; Zaitsev, Nikita

    2017-04-01

    A built-in operational regression algorithm (REA) of liquid water path (LWP) retrieval supplied by the manufacturer of the RPG-HATPRO microwave radiometer has been compared to a so-called physical algorithm (PHA) based on the inversion of the radiative transfer equation. The comparison has been performed for different scenarios of microwave observations by the RPG-HATPRO instrument that has been operating at St.Petersburg University since June 2012. The data for the scenarios have been collected within the time period December 2012 - December 2014. The estimations of bias and random error for both REA and PHA have been obtained. Special attention has been paid to the analysis of the quality of the LWP retrievals during and after rain events that have been detected by the built-in rain sensor. The estimation has been done of the time period after a rain event when the retrieval quality has to be considered as insufficient.

  15. EIT based on virtual instrument

    Directory of Open Access Journals (Sweden)

    Ma Jun

    2013-01-01

    Full Text Available Design of a electrical impedance tomography system based on virtual instrument, the author firstly introduced the virtual instrument into the electrical impedance imaging from the perspective of hardware and software. The system use DAQ of NI to simplify the hardware structure and improve the stability. Software of system combines the advantages of LABVIEW and MATLAB, and verify some algorithms. Using NI virtual instrument, the system has strong expansion and do good basis for enhancing the performance of electrical impedance imaging system.

  16. Five-day planetary waves in the middle atmosphere from Odin satellite data and ground-based instruments in Northern Hemisphere summer 2003, 2004, 2005 and 2007

    Directory of Open Access Journals (Sweden)

    A. Belova

    2008-11-01

    Full Text Available A number of studies have shown that 5-day planetary waves modulate noctilucent clouds and the closely related Polar Mesosphere Summer Echoes (PMSE at the summer mesopause. Summer stratospheric winds should inhibit wave propagation through the stratosphere and, although some numerical models (Geisler and Dickinson, 1976 do show a possibility for upward wave propagation, it has also been suggested that the upward propagation may in practice be confined to the winter hemisphere with horizontal propagation of the wave from the winter to the summer hemisphere at mesosphere heights causing the effects observed at the summer mesopause. It has further been proposed (Garcia et al., 2005 that 5-day planetary waves observed in the summer mesosphere could be excited in-situ by baroclinic instability in the upper mesosphere. In this study, we first extract and analyze 5-day planetary wave characteristics on a global scale in the middle atmosphere (up to 54 km in temperature, and up to 68 km in ozone concentration using measurements by the Odin satellite for selected days during northern hemisphere summer from 2003, 2004, 2005 and 2007. Second, we show that 5-day temperature fluctuations consistent with westward-traveling 5-day waves are present at the summer mesopause, using local ground-based meteor-radar observations. Finally we examine whether any of three possible sources of the detected temperature fluctuations at the summer mesopause can be excluded: upward propagation from the stratosphere in the summer-hemisphere, horizontal propagation from the winter-hemisphere or in-situ excitation as a result of the baroclinic instability. We find that in one case, far from solstice, the baroclinic instability is unlikely to be involved. In one further case, close to solstice, upward propagation in the same hemisphere seems to be ruled out. In all other cases, all or any of the three proposed mechanisms are consistent with the observations.

  17. Does an instrumented treadmill correctly measure the ground reaction forces?

    Directory of Open Access Journals (Sweden)

    Patrick A. Willems

    2013-11-01

    Since the 1990s, treadmills have been equipped with multi-axis force transducers to measure the three components of the ground reaction forces during walking and running. These measurements are correctly performed if the whole treadmill (including the motor is mounted on the transducers. In this case, the acceleration of the treadmill centre of mass relative to the reference frame of the laboratory is nil. The external forces exerted on one side of the treadmill are thus equal in magnitude and opposite in direction to the external forces exerted on the other side. However, uncertainty exists about the accuracy of these measures: due to friction between the belt and the tread-surface, due to the motor pulling the belt, some believe that it is not possible to correctly measure the horizontal components of the forces exerted by the feet on the belt. Here, we propose a simple model of an instrumented treadmill and we demonstrate (1 that the forces exerted by the subject moving on the upper part of the treadmill are accurately transmitted to the transducers placed under it and (2 that all internal forces – including friction – between the parts of the treadmill are cancelling each other.

  18. Coordinated Cluster, ground-based instrumentation and low-altitude satellite observations of transient poleward-moving events in the ionosphere and in the tail lobe

    Directory of Open Access Journals (Sweden)

    M. Lockwood

    Full Text Available During the interval between 8:00–9:30 on 14 January 2001, the four Cluster spacecraft were moving from the central magnetospheric lobe, through the dusk sector mantle, on their way towards intersecting the magnetopause near 15:00 MLT and 15:00 UT. Throughout this interval, the EISCAT Svalbard Radar (ESR at Longyearbyen observed a series of poleward-moving transient events of enhanced F-region plasma concentration ("polar cap patches", with a repetition period of the order of 10 min. Allowing for the estimated solar wind propagation delay of 75 ( ± 5 min, the interplanetary magnetic field (IMF had a southward component during most of the interval. The magnetic footprint of the Cluster spacecraft, mapped to the ionosphere using the Tsyganenko T96 model (with input conditions prevailing during this event, was to the east of the ESR beams. Around 09:05 UT, the DMSP-F12 satellite flew over the ESR and showed a sawtooth cusp ion dispersion signature that also extended into the electrons on the equatorward edge of the cusp, revealing a pulsed magnetopause reconnection. The consequent enhanced ionospheric flow events were imaged by the SuperDARN HF backscatter radars. The average convection patterns (derived using the AMIE technique on data from the magnetometers, the EISCAT and SuperDARN radars, and the DMSP satellites show that the associated poleward-moving events also convected over the predicted footprint of the Cluster spacecraft. Cluster observed enhancements in the fluxes of both electrons and ions. These events were found to be essentially identical at all four spacecraft, indicating that they had a much larger spatial scale than the satellite separation of the order of 600 km. Some of the events show a correspondence between the lowest energy magnetosheath electrons detected by the PEACE instrument on Cluster (10–20 eV and the topside ionospheric enhancements seen by the ESR (at 400–700 km. We suggest that a potential barrier at the

  19. Design of Onboard Instrument Based on Virtual Instrument Technology

    Institute of Scientific and Technical Information of China (English)

    TANG Baoping; ZHONG Yuanchang; QIU Jianwei

    2006-01-01

    After analyzing and comparing the traditional automobile instrument, the onboard instrument based on virtual instrument technology is designed in this paper. The PC/104 computer was employed as the core processing unit of the onboard instrument, and the several intelligent data acquisition nodes are set and connected by the CAN bus, through which the nodes can communicate with the core processing unit. The information of the vehicle's working condition can be displayed synthetically by adopting virtual instrument technology. When the working condition goes beyond its limit, the system can emit an alarm, record and storage the abnormal condition automatically, and suggest how to deal with the abnormity urgently. The development background and design idea of onboard information system were elaborated in the paper. The software, the hardware architecture and the principle of onboard information system were introduced in detail.

  20. Ground based materials science experiments

    Science.gov (United States)

    Meyer, M. B.; Johnston, J. C.; Glasgow, T. K.

    1988-01-01

    The facilities at the Microgravity Materials Science Laboratory (MMSL) at the Lewis Research Center, created to offer immediate and low-cost access to ground-based testing facilities for industrial, academic, and government researchers, are described. The equipment in the MMSL falls into three categories: (1) devices which emulate some aspect of low gravitational forces, (2) specialized capabilities for 1-g development and refinement of microgravity experiments, and (3) functional duplicates of flight hardware. Equipment diagrams are included.

  1. Ground based materials science experiments

    Science.gov (United States)

    Meyer, M. B.; Johnston, J. C.; Glasgow, T. K.

    1988-01-01

    The facilities at the Microgravity Materials Science Laboratory (MMSL) at the Lewis Research Center, created to offer immediate and low-cost access to ground-based testing facilities for industrial, academic, and government researchers, are described. The equipment in the MMSL falls into three categories: (1) devices which emulate some aspect of low gravitational forces, (2) specialized capabilities for 1-g development and refinement of microgravity experiments, and (3) functional duplicates of flight hardware. Equipment diagrams are included.

  2. Validation of ACE-FTS v2.2 measurements of HCl, HF, CCl3F and CCl2F2 using space-, balloon- and ground-based instrument observations

    Directory of Open Access Journals (Sweden)

    C. Servais

    2008-10-01

    Full Text Available Hydrogen chloride (HCl and hydrogen fluoride (HF are respectively the main chlorine and fluorine reservoirs in the Earth's stratosphere. Their buildup resulted from the intensive use of man-made halogenated source gases, in particular CFC-11 (CCl3F and CFC-12 (CCl2F2, during the second half of the 20th century. It is important to continue monitoring the evolution of these source gases and reservoirs, in support of the Montreal Protocol and also indirectly of the Kyoto Protocol. The Atmospheric Chemistry Experiment Fourier Transform Spectrometer (ACE-FTS is a space-based instrument that has been performing regular solar occultation measurements of over 30 atmospheric gases since early 2004. In this validation paper, the HCl, HF, CFC-11 and CFC-12 version 2.2 profile data products retrieved from ACE-FTS measurements are evaluated. Volume mixing ratio profiles have been compared to observations made from space by MLS and HALOE, and from stratospheric balloons by SPIRALE, FIRS-2 and Mark-IV. Partial columns derived from the ACE-FTS data were also compared to column measurements from ground-based Fourier transform instruments operated at 12 sites. ACE-FTS data recorded from March 2004 to August 2007 have been used for the comparisons. These data are representative of a variety of atmospheric and chemical situations, with sounded air masses extending from the winter vortex to summer sub-tropical conditions. Typically, the ACE-FTS products are available in the 10–50 km altitude range for HCl and HF, and in the 7–20 and 7–25 km ranges for CFC-11 and -12, respectively. For both reservoirs, comparison results indicate an agreement generally better than 5–10% above 20 km altitude, when accounting for the known offset affecting HALOE measurements of HCl and HF. Larger positive differences are however found for comparisons with single profiles from FIRS-2 and SPIRALE. For CFCs, the few coincident measurements available suggest that the differences

  3. Validation of ACE-FTS v2.2 measurements of HCl, HF, CCl3F and CCl2F2 using space-, balloon- and ground-based instrument observations

    Directory of Open Access Journals (Sweden)

    C. Tétard

    2008-02-01

    Full Text Available Hydrogen chloride (HCl and hydrogen fluoride (HF are respectively the main chlorine and fluorine reservoirs in the Earth's stratosphere. Their buildup resulted from the intensive use of man-made halogenated source gases, in particular CFC-11 (CCl3F and CFC-12 (CCl2F2, during the second half of the 20th century. It is important to continue monitoring the evolution of these source gases and reservoirs, in support of the Montreal Protocol and also indirectly of the Kyoto Protocol. The Atmospheric Chemistry Experiment Fourier Transform Spectrometer (ACE-FTS is a space-based instrument that has been performing regular solar occultation measurements of over 30 atmospheric gases since early 2004. In this validation paper, the HCl, HF, CFC-11 and CFC-12 version 2.2 profile data products retrieved from ACE-FTS measurements are evaluated. Volume mixing ratio profiles have been compared to observations made from space by MLS and HALOE, and from stratospheric balloons by SPIRALE, FIRS-2 and Mark-IV. Partial columns derived from the ACE-FTS data were also compared to column measurements from ground-based Fourier transform instruments operated at 12 sites. ACE-FTS data recorded from March 2004 to August 2007 have been used for the comparisons. These data are representative of a variety of atmospheric and chemical situations, with sounded air masses extending from the winter vortex to summer sub-tropical conditions. Typically, the ACE-FTS products are available in the 10–50 km altitude range for HCl and HF, and in the 7–20 and 7–25 km ranges for CFC-11 and CFC-12, respectively. For both reservoirs, comparison results indicate an agreement generally better than 5–10%, when accounting for the known offset affecting HALOE measurements of HCl and HF. Larger positive differences are however found for comparisons with single profiles from FIRS-2 and SPIRALE. For CFCs, the few coincident measurements available suggest that the differences probably remain

  4. Coherence between multi-instrument and multi-model atmospheric moisture retrievals and a ground-based Raman-lidar reference in the framework of the HyMeX SOP 1

    Science.gov (United States)

    Chazette, Patrick; Flamant, Cyrille; Totems, Julien; Shangt, Xiaoxia; Raut, Jean-Christophe; Boufies-Cloche, Sophie; Doerenbecher, Alexis; Ducrocq, Véronique

    2015-04-01

    The Mediterranean area is one of the main climate change hot spot regions where the water cycle needs to be better understood in order to make progress on the predictability of high-impact weather events and their evolution with global change. Characterizing the water vapour variability across the Mediterranean basin at hourly to synoptic timescales is of paramount importance to advance knowledge on the life cycle of heavy precipitation events and improve forecast in numerical weather prediction models. However, such a characterization based on a single instrument or model remains elusive and a multi-instrument, multi-model approach is needed to properly apprehend the water vapour variability at the relevant timescales, especially over data scarce regions such as oceans and seas. This approach has been undertaken during the Hydrological cycle in the Mediterranean eXperiment (HyMeX) in September and October 2012 during which part of observational effort has been established on Menorca to characterize the upwind marine low-level flow, essential to determine the strength, timing and precise location of the subsequent precipitation at the Mediterranean coastline. The ground-based Water vapor Raman Lidar (WALI), the airborne LEANDRE-2 DIAL water vapor lidar and boundary layer pressurized balloons were implemented during the first Special Observing Periods (SOP 1) and contributed to characterize water vapour variability in the vicinity of the Balearic Islands. Furthermore, analyses from regional and global numerical models (AROME-WMED, ECMWF and WRF) were also available over large domains encompassing part or the whole of the Western Mediterranean basin. We will present the comparisons of the water vapor mixing ratio profiles and water vapor integrated content derived from these different data sets and we will show that good agreements is found between them. This work is an essential step towards ensuring that the water vapour datasets (both measurements and simulations

  5. Ground-Based Calibration Of A Microwave Landing System

    Science.gov (United States)

    Kiriazes, John J.; Scott, Marshall M., Jr.; Willis, Alfred D.; Erdogan, Temel; Reyes, Rolando

    1996-01-01

    System of microwave instrumentation and data-processing equipment developed to enable ground-based calibration of microwave scanning-beam landing system (MSBLS) at distances of about 500 to 1,000 ft from MSBLS transmitting antenna. Ensures accuracy of MSBLS near touchdown point, without having to resort to expense and complex logistics of aircraft-based testing. Modified versions prove useful in calibrating aircraft instrument landing systems.

  6. Evolution of microcomputer-based medical instrumentation.

    Science.gov (United States)

    Tompkins, Willis J

    2009-01-01

    This paper provides a historical review of the evolution of the technologies that led to modern microcomputer-based medical instrumentation. I review the history of the microprocessor-based system because of the importance of the microprocessor in the design of modern medical instruments. I then give some examples of medical instruments in which the microprocessor has played a key role and in some cases has even empowered us to develop new instruments that were not possible before. I include a discussion of the role of the microprocessor-based personal computer in development of medical instruments.

  7. Market-based Economic Instruments

    DEFF Research Database (Denmark)

    Klemmensen, Børge

    2007-01-01

    Grundkategorien her er markedet som den optimale allokeringsmekanisme for de belastninger, som de økonomiske instrumenter / miljøskatterne påfører. Det mest omfattende og spektakulære eksempel på markedet som allokatorer af skatter er EU's børs for forureningstilladelser, dvs reelt CO-2 beskatnin...

  8. Multi-instrument observations of midlatitude summer nighttime anomaly from satellite and ground

    Science.gov (United States)

    Yamamoto, Mamoru; Thampi, Smitha V.; Liu, Huixin; Lin, Charles

    "Midlatitude Summer Nighttime Anomaly (MSNA)" is a phenomenon that the nighttime elec-tron densities exceed the daytime values on almost all days in summer over latitudes of 33-34N of more. We recently found the MSNA over the northeast Asian region from multi-instrument observations. The observations include the tomography analysis based on the chain of digital beacon receivers at Shionomisaki (33.45N, 135.8E), Shigaraki (34.85N, 136.1E), and Fukui (36.06N,136E), the ionosonde network over Japan (especially data from Wakkanai (45.4N, 141.7E)), ground-based GPS TEC observations using the GEONET. Also from satellites, CHAMP in situ electron density measurements, and Formosat3/COSMIC (F3/C) occultation measurements are useful to confirm the presence of MSNA over this region. In the presen-tation we show detailed features of the MSNA based on these multi-instrument, and discuss importance of the neutral atmosphere as a driver of the phenomenon.

  9. The 2006 SPIE Symposium on Astronomical Telescopes and Instrumentation ? Observing the Universe from Ground and Space

    Science.gov (United States)

    Moorwood, A.

    2006-06-01

    The most recent of these biennial SPIE (The International Society for Optical Engineering) Symposia was held from 24-31 May in the Orlando World Center Marriott Resort & Convention Center in Florida, USA. Over the last decade, these meetings have grown to become the main forum for presenting and discussing all aspects of ground-based, airborne and space telescopes and their instrumentation, including associated advances in technology, software, operations and even astronomical results. As a consequence the meetings are large and well attended by people at all levels in the process of initiating, approving, implementing and operating astronomical projects and facilities. This year there were ~ 1700 registered participants who presented ~ 1600 papers and posters in the following 12 parallel conferences which formed the heart of the meeting.

  10. VELA: A Microprocessor-Based Laboratory Instrument.

    Science.gov (United States)

    Lambert, Andrew

    1983-01-01

    Provides a general description of a preprogramed, microprocessor-based laboratory instrument, discussing its use in monitoring: (1) environmental changes; (2) distribution of count rates from a radioactive source, and (3) motion on an air tract. Includes list of the instrument's various capabilities: frequency meter, voltmeter, interval timer, and…

  11. The STACEE Ground-Based Gamma-ray Observatory

    Science.gov (United States)

    Ragan, Ken

    2002-04-01

    The Solar Tower Atmospheric Cherenkov Effect Experiment (STACEE) is a ground-based instrument designed to study astrophysical sources of gamma rays in the energy range from 50 to 500 GeV using an array of heliostat mirrors at the National Solar Thermal Test Facility in New Mexico. The mirrors collect Cherenkov light generated by gamma-ray air showers and concentrate it onto cameras composed of photomultiplier tubes. The STACEE instrument is now complete, and uses a total of 64 heliostats. Prototype instruments, using smaller numbers of heliostats, have previously detected gamma emission from both the Crab Nebula and the Active Galactic Nucleus Mrk421. The complete instrument has a lower threshold -- approximately 50 GeV -- than those prototypes due to superior triggering and electronics, including flash ADCs for every channel.We will discuss the performance of the complete instrument in its first full season of operation, and present preliminary results of selected observations.

  12. Space-based monitoring of ground deformation

    Science.gov (United States)

    Nobakht Ersi, Fereydoun; Safari, Abdolreza; Gamse, Sonja

    2016-07-01

    Ground deformation monitoring is valuable to understanding of the behaviour of natural phenomena. Space-Based measurement systems such as Global Positioning System are useful tools for continuous monitoring of ground deformation. Ground deformation analysis based on space geodetic techniques have provided a new, more accurate, and reliable source of information for geodetic positioning which is used to detect deformations of the Ground surface. This type of studies using displacement fields derived from repeated measurments of space-based geodetic networks indicates how crucial role the space geodetic methods play in geodynamics. The main scope of this contribution is to monitor of ground deformation by obtained measurements from GPS sites. We present ground deformation analysis in three steps: a global congruency test on daily coordinates of permanent GPS stations to specify in which epochs deformations occur, the localization of the deformed GPS sites and the determination of deformations.

  13. Ground-based observations of exoplanet atmospheres

    NARCIS (Netherlands)

    Mooij, Ernst Johan Walter de

    2011-01-01

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

  14. Ground-based observations of exoplanet atmospheres

    NARCIS (Netherlands)

    Mooij, Ernst Johan Walter de

    2011-01-01

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

  15. Current trends in ground based solar magnetometry

    Science.gov (United States)

    Gosain, Sanjay

    2016-07-01

    Continuous observations of the sun, over more than a century, have led to several important discoveries in solar astronomy. These include the discovery of the solar magnetism and its cyclic modulation, active region formation and decay and their role in energetic phenomena such as fares and coronal mass ejections (CMEs), fine structure and dynamics of the sunspots and small-scale organization of the magnetic flux in the form of flux tubes and so forth. In this article we give a brief overview of advancements in solar observational techniques in recent decades and the results obtained from the such observations. These include techniques to achieve high angular resolution, high spectral and polarimetric sensitivity and innovative new detectors. A wide range of spatial, temporal and spectral domains exploited by solar astronomers to understand the solar phenomena are discussed. Many new upcoming telescopes and instruments that are designed to address different aspects of solar physics problems are briefly described. Finally, we discuss the advantages of observing from the ground and how they can complement space-based observations.

  16. Fresnel zones for ground-based antennas

    DEFF Research Database (Denmark)

    Andersen, J. Bach

    1964-01-01

    The ordinary Fresnel zone concept is modified to include the influence of finite ground conductivity. This is important for ground-based antennas because the influence on the radiation pattern of irregularities near the antenna is determined by the amplitude and phase of the groundwave. A new...

  17. Ground tests with active neutron instrumentation for the planetary science missions

    Energy Technology Data Exchange (ETDEWEB)

    Litvak, M.L., E-mail: litvak@mx.iki.rssi.ru [Space Research Institute, RAS, Moscow 117997 (Russian Federation); Mitrofanov, I.G.; Sanin, A.B. [Space Research Institute, RAS, Moscow 117997 (Russian Federation); Jun, I. [Jet Propulsion Laboratory, Pasadena, CA USA (United States); Kozyrev, A.S. [Space Research Institute, RAS, Moscow 117997 (Russian Federation); Krylov, A.; Shvetsov, V.N.; Timoshenko, G.N. [Joint Institute for Nuclear Research, Dubna (Russian Federation); Starr, R. [Catholic University of America, Washington DC (United States); Zontikov, A. [Joint Institute for Nuclear Research, Dubna (Russian Federation)

    2015-07-11

    We present results of experimental work performed with a spare flight model of the DAN/MSL instrument in a newly built ground test facility at the Joint Institute for Nuclear Research. This instrument was selected for the tests as a flight prototype of an active neutron spectrometer applicable for future landed missions to various solid solar system bodies. In our experiment we have fabricated simplified samples of planetary material and tested the capability of neutron activation methods to detect thin layers of water/water ice lying on top of planetary dry regolith or buried within a dry regolith at different depths.

  18. LOAC: a small aerosol optical counter/sizer for ground-based and balloon measurements of the size distribution and nature of atmospheric particles - Part 1: Principle of measurements and instrument evaluation

    Science.gov (United States)

    Renard, J.-B.; Dulac, F.; Berthet, G.; Lurton, T.; Vignelles, D.; Jégou, F.; Tonnelier, T.; Thaury, C.; Jeannot, M.; Couté, B.; Akiki, R.; Verdier, N.; Mallet, M.; Gensdarmes, F.; Charpentier, P.; Duverger, V.; Dupont, J.-C.; Mesmin, S.; Elias, T.; Crenn, V.; Sciare, J.; Giacomoni, J.; Gobbi, M.; Hamonou, E.; Olafsson, H.; Dagsson-Waldhauserova, P.; Camy-Peyret, C.; Mazel, C.; Décamps, T.; Piringer, M.; Surcin, J.; Daugeron, D.

    2015-09-01

    The study of aerosols in the troposphere and in the stratosphere is of major importance both for climate and air quality studies. Among the numerous instruments available, aerosol particles counters provide the size distribution in diameter range from few hundreds of nm to few tens of μm. Most of them are very sensitive to the nature of aerosols, and this can result in significant biases in the retrieved size distribution. We describe here a new versatile optical particle/sizer counter (OPC) named LOAC (Light Optical Aerosol Counter), which is light and compact enough to perform measurements not only at the surface but under all kinds of balloons in the troposphere and in the stratosphere. LOAC is an original OPC performing observations at two scattering angles. The first one is around 12°, and is almost insensitive to the nature of the particles; the second one is around 60° and is strongly sensitive to the refractive index of the particles. By combining measurement at the two angles, it is possible to retrieve accurately the size distribution and to estimate the nature of the dominant particles (droplets, carbonaceous, salts and mineral particles) in several size classes. This topology is based on calibration charts obtained in the laboratory. Several campaigns of cross-comparison of LOAC with other particle counting instruments and remote sensing photometers have been conducted to validate both the size distribution derived by LOAC and the retrieved particle number density. The topology of the aerosols has been validated in well-defined conditions including urban pollution, desert dust episodes, fog, and cloud. Comparison with reference aerosol mass monitoring instruments also shows that the LOAC measurements can be successfully converted to mass concentrations. All these tests indicate that no bias is present in the LOAC measurements and in the corresponding data processing.

  19. LOAC: a small aerosol optical counter/sizer for ground-based and balloon measurements of the size distribution and nature of atmospheric particles – Part 1: Principle of measurements and instrument evaluation

    Directory of Open Access Journals (Sweden)

    J.-B. Renard

    2015-01-01

    Full Text Available The study of aerosols in the troposphere and in the stratosphere is of major importance both for climate and air quality studies. Among the numerous instruments available, aerosol particles counters provide the size distribution in diameter range from few hundreds of nm to few tens of μm. Most of them are very sensitive to the nature of aerosols, and this can result in significant biases in the retrieved size distribution. We describe here a new versatile optical particle/sizer counter (OPC named LOAC (Light Optical Aerosols Counter, which is light and compact enough to perform measurements not only at the surface but under all kinds of balloons in the troposphere and in the stratosphere. LOAC is an original OPC performing observations at two scattering angles. The first one is around 12°, and is almost insensitive to the nature of the particles; the second one is around 60° and is strongly sensitive to the refractive index of the particles. By combining measurement at the two angles, it is possible to retrieve accurately the size distribution and to estimate the nature of the dominant particles (droplets, carbonaceous, salts and mineral particles in several size classes. This speciation is based on calibration charts obtained in the laboratory. Several campaigns of cross-comparison of LOAC with other particle counting instruments and remote sensing photometers have been conducted to validate both the size distribution derived by LOAC and the retrieved particle number density. The speciation of the aerosols has been validated in well-defined conditions including urban pollution, desert dust episodes, fog, and cloud. Comparison with reference aerosol mass monitoring instruments also shows that the LOAC measurements can be successfully converted to mass concentrations. All these tests indicate that no bias is present in the LOAC measurements and in the corresponding data processing.

  20. Ground-based Infrared Observations of Water Vapor and Hydrogen Peroxide in the Atmosphere of Mars

    Science.gov (United States)

    Encrenaz, T.; Greathouse, T. K.; Bitner, M.; Kruger, A.; Richter, M. J.; Lacy, J. H.; Bézard, B.; Fouchet, T.; Lefevre, F.; Forget, F.; Atreya, S. K.

    2008-11-01

    Ground-based observations of water vapor and hydrogen peroxide have been obtained in the thermal infrared range, using the TEXES instrument at the NASA Infrared Telescope Facility, for different times of the seasonal cycle.

  1. Instrumented borehole drilling for interface identification in intricate weathered granite ground engineering

    Institute of Scientific and Technical Information of China (English)

    Zhuoying Tan; Meifeng Cai; Z.Q. Yue; L.G.Tham; C.F.Lee

    2007-01-01

    The successful application in drilling for HK simple weathered granite foundation has revealed its further use in instrumented drilling system as a ground investigation tool in the detection of other lithology formations, geohazards, underground water, and boundary of orebody. To expand the further use and test the accuracy in identification of formation, an R-20 rotary-hydraulic drill rig was instrumented with a digital drilling process monitoring system (DPM) for drilling in an intricate decomposed granite site.In this test ground, the boreholes revealed that the weathered granite alternately changes between moderate and strong. The qualitative and quantitative analysis of the penetrating parameters, indicates the effective thrust force, rotary speed, flushing pressure, penetrating rate, and displacement of the bit fluctuate at ground interfaces. It shows that the parameters get a good response with the change of rock strength at the interfaces, which can reveal the change of the intricate granite formation. Besides, a variable-slope method has been established, for identification of dominative and subsidiary interfaces in the granite site. The result from a t-test shows that the confidence of the instrumented drilling system in identification of the geotechnical interfaces is up to 99%.

  2. Review of Ground Characterization by Using Instrumented Drills for Underground Mining and Construction

    Science.gov (United States)

    Kahraman, Sair; Rostami, Jamal; Naeimipour, Ali

    2016-02-01

    In underground mining, many miners are injured or lose their lives because of roof/pillar instability each year, and this is a persistent safety risk. Characterization of overlying strata is important for the design of safe and cost-effective ground support systems. Entry roof characterization can be performed by geological back-mapping of the ground using various methods such as geophysical logging, borescoping, rock mass rating, and intelligent roof bolt drilling systems. This paper offers a brief review of mine roof characterization methods, followed by an introduction to and discussion of roof characterization methods using instrumented roof bolters. A brief overview of the various instrumentation systems developed for roof bolt drills is presented. The results of the preliminary study and initial testing indicate that, despite recent improvements in the area of ground characterization by instrumented drills, there are still several issues that must be addressed to improve the efficiency and accuracy of existing systems. A summary of suggested improvements is provided.

  3. Ground-based observations of Kepler asteroseismic targets

    CERN Document Server

    Uytterhoeven, K; Southworth, J; Randall, S; Ostensen, R; Molenda-Zakowicz, J; Marconi, M; Kurtz, D W; Kiss, L; Gutierrez-Soto, J; Frandsen, S; De Cat, P; Bruntt, H; Briquet, M; Zhang, X B; Telting, J H; Steslicki, M; Ripepi, V; Pigulski, A; Paparo, M; Oreiro, R; Choong, Ngeow Chow; Niemczura, E; Nemec, J; Narwid, A; Mathias, P; Martin-Ruiz, S; Lehman, H; Kopacki, G; Karoff, C; Jackiewicz, J; Henden, A A; Handler, G; Grigachene, A; Green, E M; Garrido, R; Machado, L Fox; Debosscher, J; Creevey, O L; Catanzaro, G; Bognar, Z; Biazzo, K; Bernabei, S

    2010-01-01

    We present the ground-based activities within the different working groups of the Kepler Asteroseismic Science Consortium (KASC). The activities aim at the systematic characterization of the 5000+ KASC targets, and at the collection of ground-based follow-up time-series data of selected promising Kepler pulsators. So far, 35 different instruments at 30 telescopes on 22 different observatories in 12 countries are in use, and a total of more than 530 observing nights has been awarded. (Based on observations made with the Isaac Newton Telescope, William Herschel Telescope, Nordic Optical Telescope, Telescopio Nazionale Galileo, Mercator Telescope (La Palma, Spain), and IAC-80 (Tenerife, Spain). Also based on observations taken at the observatories of Sierra Nevada, San Pedro Martir, Vienna, Xinglong, Apache Point, Lulin, Tautenburg, Loiano, Serra la Nave, Asiago, McDonald, Skinakas, Pic du Midi, Mauna Kea, Steward Observatory, Bialkow Observatory of the Wroclaw University, Piszkesteto Mountain Station, Observato...

  4. Instrument Display Visual Angles for Conventional Aircraft and the MQ-9 Ground Control Station

    Science.gov (United States)

    Bendrick, Gregg A.; Kamine, Tovy Haber

    2008-01-01

    Aircraft instrument panels should be designed such that primary displays are in optimal viewing location to minimize pilot perception and response time. Human Factors engineers define three zones (i.e. "cones") of visual location: 1) "Easy Eye Movement" (foveal vision); 2) "Maximum Eye Movement" (peripheral vision with saccades), and 3) "Head Movement" (head movement required). Instrument display visual angles were measured to determine how well conventional aircraft (T-34, T-38, F- 15B, F-16XL, F/A-18A, U-2D, ER-2, King Air, G-III, B-52H, DC-10, B747-SCA) and the MQ-9 ground control station (GCS) complied with these standards, and how they compared with each other. Methods: Selected instrument parameters included: attitude, pitch, bank, power, airspeed, altitude, vertical speed, heading, turn rate, slip/skid, AOA, flight path, latitude, longitude, course, bearing, range and time. Vertical and horizontal visual angles for each component were measured from the pilot s eye position in each system. Results: The vertical visual angles of displays in conventional aircraft lay within the cone of "Easy Eye Movement" for all but three of the parameters measured, and almost all of the horizontal visual angles fell within this range. All conventional vertical and horizontal visual angles lay within the cone of "Maximum Eye Movement". However, most instrument vertical visual angles of the MQ-9 GCS lay outside the cone of "Easy Eye Movement", though all were within the cone of "Maximum Eye Movement". All the horizontal visual angles for the MQ-9 GCS were within the cone of "Easy Eye Movement". Discussion: Most instrument displays in conventional aircraft lay within the cone of "Easy Eye Movement", though mission-critical instruments sometimes displaced less important instruments outside this area. Many of the MQ-9 GCS systems lay outside this area. Specific training for MQ-9 pilots may be needed to avoid increased response time and potential error during flight.

  5. Illumination compensation in ground based hyperspectral imaging

    Science.gov (United States)

    Wendel, Alexander; Underwood, James

    2017-07-01

    Hyperspectral imaging has emerged as an important tool for analysing vegetation data in agricultural applications. Recently, low altitude and ground based hyperspectral imaging solutions have come to the fore, providing very high resolution data for mapping and studying large areas of crops in detail. However, these platforms introduce a unique set of challenges that need to be overcome to ensure consistent, accurate and timely acquisition of data. One particular problem is dealing with changes in environmental illumination while operating with natural light under cloud cover, which can have considerable effects on spectral shape. In the past this has been commonly achieved by imaging known reference targets at the time of data acquisition, direct measurement of irradiance, or atmospheric modelling. While capturing a reference panel continuously or very frequently allows accurate compensation for illumination changes, this is often not practical with ground based platforms, and impossible in aerial applications. This paper examines the use of an autonomous unmanned ground vehicle (UGV) to gather high resolution hyperspectral imaging data of crops under natural illumination. A process of illumination compensation is performed to extract the inherent reflectance properties of the crops, despite variable illumination. This work adapts a previously developed subspace model approach to reflectance and illumination recovery. Though tested on a ground vehicle in this paper, it is applicable to low altitude unmanned aerial hyperspectral imagery also. The method uses occasional observations of reference panel training data from within the same or other datasets, which enables a practical field protocol that minimises in-field manual labour. This paper tests the new approach, comparing it against traditional methods. Several illumination compensation protocols for high volume ground based data collection are presented based on the results. The findings in this paper are

  6. Multipotenciostat System Based on Virtual Instrumentation

    Directory of Open Access Journals (Sweden)

    Arrieta-Almario Álvaro Angel

    2014-07-01

    Full Text Available To carry out this project an electronic multichannel system of electrochemical measurement or multipotenciostat was developed. It is based on the cyclic voltammetry measurement technique, controlled by a computer that monitors, by means of an electronic circuit, both the voltage generated from the Pc and supplied to an electrolytic cell, and the current that flows through the electrodes of it. To design the application software and the user interface, Virtual Instrumentation was used. On the other hand, to perform the communication between the multipotenciostat circuit and the designed software, the National Instruments NI9263 and NI9203 acquisition modules were used. The system was tested on a substance with a known REDOX property, as well as to discriminate and classify some samples of coffee.

  7. Ground based spectroscopy of hot Jupiters

    Science.gov (United States)

    Waldmann, Ingo

    2010-05-01

    It has been shown in recent years with great success that spectroscopy of exoplanetary atmospheres is feasible using space based observatories such as the HST and Spitzer. However, with the end of the Spitzer cold-phase, space based observations in the near to mid infra-red are limited, which will remain true until the the onset of the JWST. The importance of developing methods of ground based spectroscopic analysis of known hot Jupiters is therefore apparent. In the past, various groups have attempted exoplanetary spectroscopy using ground based facilities and various techniques. Here I will present results using a novel spectral retrieval method for near to mid infra-red emission and transmission spectra of exoplanetary atmospheres taken from the ground and discuss the feasibility of future ground-based spectroscopy in a broader context. My recently commenced PhD project is under the supervision of Giovanna Tinetti (University College London) and in collaboration with J. P. Beaulieu (Institut d'Astrophysique de Paris), Mark Swain and Pieter Deroo (Jet Propulsion Laboratory, Caltech).

  8. Using Model-Based Reasoning for Autonomous Instrument Operation

    Science.gov (United States)

    Johnson, Mike; Rilee, M.; Truszkowski, W.; Powers, Edward I. (Technical Monitor)

    2000-01-01

    Multiprobe missions are an important part of NASA's future: Cluster, Magnetospheric Multi Scale, Global Electrodynamics and Magnetospheric Constellation are representatives from the Sun-Earth Connections Theme. To make such missions robust, reliable, and affordable, ideally the many spacecraft of a constellation must be at least as easy to operate as one spacecraft is today. To support this need for scalability, science instrumentation must become increasingly easy to operate, even as this same instrumentation becomes more capable and advanced. Communication and control resources will be at a premium for future instruments. Many missions will be out of contact with ground operators for extended periods either to reduce operations cost or because of orbits that limit communication to weekly perigee transits. Autonomous capability is necessary if such missions are to effectively achieve their operational objectives. An autonomous system is one that acts given its situation in a mission appropriate manner without external direction to achieve mission goals. To achieve this capability autonomy must be built into the system through judicious design or through a built-in intelligence that recognizes system state and manages system response. To recognize desired or undesired system states, the system must have an implicit or explicit understanding of its expected states given its history and self observations. The systems we are concerned with, science instruments, can have stringent requirements for system state knowledge in addition to requirements driven by health and safety concerns. Without accurate knowledge of the system state, the usefulness of the science instrument may be severely limited. At the same time, health and safety concerns often lead to overly conservative instrument operations further reducing the effectiveness of the instrument. These requirements, coupled with overall mission requirements including lack of communication opportunities and tolerance

  9. Ground-Based Lidar for Atmospheric Boundary Layer Ozone Measurements

    Science.gov (United States)

    Kuang, Shi; Newchurch, Michael J.; Burris, John; Liu, Xiong

    2013-01-01

    Ground-based lidars are suitable for long-term ozone monitoring as a complement to satellite and ozonesonde measurements. However, current ground-based lidars are unable to consistently measure ozone below 500 m above ground level (AGL) due to both engineering issues and high retrieval sensitivity to various measurement errors. In this paper, we present our instrument design, retrieval techniques, and preliminary results that focus on the high-temporal profiling of ozone within the atmospheric boundary layer (ABL) achieved by the addition of an inexpensive and compact mini-receiver to the previous system. For the first time, to the best of our knowledge, the lowest, consistently achievable observation height has been extended down to 125 m AGL for a ground-based ozone lidar system. Both the analysis and preliminary measurements demonstrate that this lidar measures ozone with a precision generally better than 10% at a temporal resolution of 10 min and a vertical resolution from 150 m at the bottom of the ABL to 550 m at the top. A measurement example from summertime shows that inhomogeneous ozone aloft was affected by both surface emissions and the evolution of ABL structures.

  10. Ground-based lidar for atmospheric boundary layer ozone measurements.

    Science.gov (United States)

    Kuang, Shi; Newchurch, Michael J; Burris, John; Liu, Xiong

    2013-05-20

    Ground-based lidars are suitable for long-term ozone monitoring as a complement to satellite and ozonesonde measurements. However, current ground-based lidars are unable to consistently measure ozone below 500 m above ground level (AGL) due to both engineering issues and high retrieval sensitivity to various measurement errors. In this paper, we present our instrument design, retrieval techniques, and preliminary results that focus on the high-temporal profiling of ozone within the atmospheric boundary layer (ABL) achieved by the addition of an inexpensive and compact mini-receiver to the previous system. For the first time, to the best of our knowledge, the lowest, consistently achievable observation height has been extended down to 125 m AGL for a ground-based ozone lidar system. Both the analysis and preliminary measurements demonstrate that this lidar measures ozone with a precision generally better than ±10% at a temporal resolution of 10 min and a vertical resolution from 150 m at the bottom of the ABL to 550 m at the top. A measurement example from summertime shows that inhomogeneous ozone aloft was affected by both surface emissions and the evolution of ABL structures.

  11. Ontology Based Vocabulary Matching for Oceanographic Instruments

    Science.gov (United States)

    Chen, Yu; Shepherd, Adam; Chandler, Cyndy; Arko, Robert; Leadbetter, Adam

    2014-05-01

    Data integration act as the preliminary entry point as we enter the era of big data in many scientific domains. However the reusefulness of various dataset has met the hurdle due to different initial of interests of different parties, therefore different vocabularies in describing similar or semantically related concepts. In this scenario it is vital to devise an automatic or semi-supervised algorithm to facilitate the convergence of different vocabularies. The Ocean Data Interoperability Platform (ODIP) seeks to increase data sharing across scientific domains and international boundaries by providing a forum to harmonize diverse regional data systems. ODIP participants from the US include the Rolling Deck to Repository (R2R) program, whose mission is to capture, catalog, and describe the underway/environmental sensor data from US oceanographic research vessels and submit the data to public long-term archives. In an attempt to harmonize these regional data systems, especially vocabularies, R2R recognizes the value of the SeaDataNet vocabularies served by the NERC Vocabulary Server (NVS) hosted at the British Oceanographic Data Centre as a trusted, authoritative source for describing many oceanographic research concepts such as instrumentation. In this work, we make use of the semantic relations in the vocabularies served by NVS to build a Bayesian network and take advantage of the idea of entropy in evaluating the correlation between different concepts and keywords. The performance of the model is evaluated against matching instruments from R2R against the SeaDataNet instrument vocabularies based on calculated confidence scores in the instrument pairings. These pairings with their scores can then be analyzed for assertion growing the interoperability of the R2R vocabulary through its links to the SeaDataNet entities.

  12. Entropy-based Tuning of Musical Instruments

    CERN Document Server

    Hinrichsen, Haye

    2012-01-01

    The human sense of hearing perceives a combination of sounds 'in tune' if the corresponding harmonic spectra are correlated, meaning that the neuronal excitation pattern in the inner ear exhibits some kind of order. Based on this observation it is suggested that musical instruments such as pianos can be tuned by minimizing the Shannon entropy of suitably preprocessed Fourier spectra. This method reproduces not only the correct stretch curve but also similar pitch fluctuations as in the case of high-quality aural tuning.

  13. The optical performance of the PILOT instrument from ground end-to-end tests

    Science.gov (United States)

    Misawa, R.; Bernard, J.-Ph.; Longval, Y.; Ristorcelli, I.; Ade, P.; Alina, D.; André, Y.; Aumont, J.; Bautista, L.; de Bernardis, P.; Boulade, O.; Bousqet, F.; Bouzit, M.; Buttice, V.; Caillat, A.; Chaigneau, M.; Charra, M.; Crane, B.; Douchin, F.; Doumayrou, E.; Dubois, J. P.; Engel, C.; Griffin, M.; Foenard, G.; Grabarnik, S.; Hargrave, P.; Hughes, A.; Laureijs, R.; Leriche, B.; Maestre, S.; Maffei, B.; Marty, C.; Marty, W.; Masi, S.; Montel, J.; Montier, L.; Mot, B.; Narbonne, J.; Pajot, F.; Pérot, E.; Pimentao, J.; Pisano, G.; Ponthieu, N.; Rodriguez, L.; Roudil, G.; Salatino, M.; Savini, G.; Simonella, O.; Saccoccio, M.; Tauber, J.; Tucker, C.

    2017-06-01

    The Polarized Instrument for Long-wavelength Observation of the Tenuous interstellar medium ( PILOT) is a balloon-borne astronomy experiment designed to study the linear polarization of thermal dust emission in two photometric bands centred at wavelengths 240 μm (1.2 THz) and 550 μm (545 GHz), with an angular resolution of a few arcminutes. Several end-to-end tests of the instrument were performed on the ground between 2012 and 2014, in order to prepare for the first scientific flight of the experiment that took place in September 2015 from Timmins, Ontario, Canada. This paper presents the results of those tests, focussing on an evaluation of the instrument's optical performance. We quantify image quality across the extent of the focal plane, and describe the tests that we conducted to determine the focal plane geometry, the optimal focus position, and sources of internal straylight. We present estimates of the detector response, obtained using an internal calibration source, and estimates of the background intensity and background polarization.

  14. FGMOS Based Voltage-Controlled Grounded Resistor

    Directory of Open Access Journals (Sweden)

    R. Pandey

    2010-09-01

    Full Text Available This paper proposes a new floating gate MOSFET (FGMOS based voltage-controlled grounded resistor. In the proposed circuit FGMOS operating in the ohmic region is linearized by another conventional MOSFET operating in the saturation region. The major advantages of FGMOS based voltage-controlled grounded resistor (FGVCGR are simplicity, low total harmonic distortion (THD, and low power consumption. A simple application of this FGVCGR as a tunable high-pass filter is also suggested. The proposed circuits operate at the supply voltages of +/-0.75 V. The circuits are designed and simulated using SPICE in 0.25-µm CMOS technology. The simulation results of FGVCGR demonstrate a THD of 0.28% for the input signal 0.32 Vpp at 45 kHz, and a maximum power consumption of 254 µW.

  15. Space and Ground-Based Infrastructures

    Science.gov (United States)

    Weems, Jon; Zell, Martin

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

  16. Development of Ground-Based Plant Sentinels

    Science.gov (United States)

    2007-11-02

    plants in response to different strains of Pseudomonas syringae. Planta . 217:767-775. De Moraes CM, Schultz JC, Mescher MC, Tumlinson JH. (2004...09-30-2004 Final Technical _ April 2001 - April 2003 4. TITLE AND SUBTITLE 5a. CONTRACT NUMBER Developing Plants as Ground-based Sentinels 5b. GRANT...SUPPLEMENTARY NOTES 14. ABSTRACT 9 "Z Plants emit volatile mixes characteristic of exposure to both plant and animal (insect) pathogens (bacteria and fungi). The

  17. Ground-based Measurements of Next Generation Spectroradiometric Standard Stars

    Science.gov (United States)

    McGraw, John T.

    2013-01-01

    Accurate, radiometric standards are essential to the future of ground- and space-based astronomy and astrophysics. While astronomers tend to think of “standard stars” as available calibration sources, progress at NIST to accurately calibrate inexpensive, easy to use photodiode detectors as spectroradiometric standards from 200 nm to 1800 nm allows referencing astronomical measurements to these devices. Direction-, time-, and wavelength-dependent transmission of Earth’s atmosphere is the single largest source of error for ground-based radiometric measurement of astronomical objects. Measurements and impacts of atmospheric extinction - scattering and absorption - on imaging radiometric and spectroradiometric measurements are described. The conclusion is that accurate real-time measurement of extinction in the column of atmosphere through which standard star observations are made, over the spectral region being observed and over the field of view of the telescope are required. New techniques to directly and simultaneously measure extinction in the column of atmosphere through which observations are made are required. Our direct extinction measurement solution employs three small facility-class instruments working in parallel: a lidar to measure rapidly time variable transmission at three wavelengths with uncertainty of 0.25% per airmass, a spectrophotometer to measure rapidly wavelength variable extinction with sub-1% precision per nanometer resolution element from 350 to 1050nm, and a wide-field camera to measure angularly variable extinction over the field of view. These instruments and their operation will be described. We assert that application of atmospheric metadata provided by this instrument suite corrects for a significant fraction of systematic errors currently limiting radiometric precision, and provides a major step towards measurements that are provably dominated by random noise.

  18. Exploring the relationship between monitored ground-based and satellite aerosol measurements over the City of Johannesburg

    CSIR Research Space (South Africa)

    Garland, Rebecca M

    2012-09-01

    Full Text Available This project studied the relationship between aerosol optical depth (AOD) from the Multi-angle Imaging SpectroRadiometer (MISR) instrument on the Terra satellite, and ground-based monitored particulate matter (PM) mass concentrations measured...

  19. Instrumentation

    Institute of Scientific and Technical Information of China (English)

    2015-01-01

    Journal Scope:Instrumentation is a high quality open access peer reviewed research journal.Authors are solicited to contribute to these journals by submitting articles that illustrate most up-to-date research results,projects,surveying works and industrial experiences that describe significant advances in the instrumental science.The mission of the Instrumentation is

  20. Instrumentation

    Institute of Scientific and Technical Information of China (English)

    2016-01-01

    Journal Scope:Instrumentation is a high quality open access peer reviewed research journal.Authors are solicited to contribute to these journals by submitting articles that illustrate most up-to-date research results,projects,surveying works and industrial experiences that describe significant advances in the instrumental science.The mission of the Instrumentation is to provide a platform for the researchers,academicians,

  1. Atmospheric contamination for CMB ground-based observations

    CERN Document Server

    Errard, J; Akiba, Y; Arnold, K; Atlas, M; Baccigalupi, C; Barron, D; Boettger, D; Borrill, J; Chapman, S; Chinone, Y; Cukierman, A; Delabrouille, J; Dobbs, M; Ducout, A; Elleflot, T; Fabbian, G; Feng, C; Feeney, S; Gilbert, A; Goeckner-Wald, N; Halverson, N W; Hasegawa, M; Hattori, K; Hazumi, M; Hill, C; Holzapfel, W L; Hori, Y; Inoue, Y; Jaehnig, G C; Jaffe, A H; Jeong, O; Katayama, N; Kaufman, J; Keating, B; Kermish, Z; Keskitalo, R; Kisner, T; Jeune, M Le; Lee, A T; Leitch, E M; Leon, D; Linder, E; Matsuda, F; Matsumura, T; Miller, N J; Myers, M J; Navaroli, M; Nishino, H; Okamura, T; Paar, H; Peloton, J; Poletti, D; Puglisi, G; Rebeiz, G; Reichardt, C L; Richards, P L; Ross, C; Rotermund, K M; Schenck, D E; Sherwin, B D; Siritanasak, P; Smecher, G; Stebor, N; Steinbach, B; Stompor, R; Suzuki, A; Tajima, O; Takakura, S; Tikhomirov, A; Tomaru, T; Whitehorn, N; Wilson, B; Yadav, A; Zahn, O

    2015-01-01

    Atmosphere is one of the most important noise sources for ground-based Cosmic Microwave Background (CMB) experiments. By increasing optical loading on the detectors, it amplifies their effective noise, while its fluctuations introduce spatial and temporal correlations between detected signals. We present a physically motivated 3d-model of the atmosphere total intensity emission in the millimeter and sub-millimeter wavelengths. We derive an analytical estimate for the correlation between detectors time-ordered data as a function of the instrument and survey design, as well as several atmospheric parameters such as wind, relative humidity, temperature and turbulence characteristics. Using numerical computation, we examine the effect of each physical parameter on the correlations in the time series of a given experiment. We then use a parametric-likelihood approach to validate the modeling and estimate atmosphere parameters from the POLARBEAR-I project first season data set. We compare our results to previous st...

  2. Observational Selection Effects with Ground-based Gravitational Wave Detectors

    CERN Document Server

    Chen, Hsin-Yu; Vitale, Salvatore; Holz, Daniel E; Katsavounidis, Erik

    2016-01-01

    Ground-based interferometers are not perfectly all-sky instruments, and it is important to account for their behavior when considering the distribution of detected events. In particular, the LIGO detectors are most sensitive to sources above North America and the Indian Ocean and, as the Earth rotates, the sensitive regions are swept across the sky. However, because the detectors do not acquire data uniformly over time, there is a net bias on detectable sources' right ascensions. Both LIGO detectors preferentially collect data during their local night; it is more than twice as likely to be local midnight than noon when both detectors are operating. We discuss these selection effects and how they impact LIGO's observations and electromagnetic follow-up. Beyond galactic foregrounds associated with seasonal variations, we find that equatorial observatories can access over $80\\%$ of the localization probability, while mid-latitudes will access closer to $70\\%$. Facilities located near the two LIGO sites can obser...

  3. Progress in the ULTRA 1-m ground-based telescope

    Science.gov (United States)

    Romeo, Robert C.; Martin, Robert N.; Twarog, Bruce; Anthony-Twarog, Barbara; Taghavi, Ray; Hale, Rick; Etzel, Paul; Fesen, Rob; Shawl, Steve

    2006-06-01

    We present the technical status of the Ultra Lightweight Telescope for Research in Astronomy (ULTRA) program. The program is a 3-year Major Research Instrumentation (MRI) program funded by NSF. The MRI is a collaborative effort involving Composite Mirror Applications, Inc. (CMA), University of Kansas, San Diego State University and Dartmouth College. Objectives are to demonstrate the feasibility of carbon fiber reinforced plastic (CFRP) composite mirror technology for ground-based optical telescopes. CMA is spearheading the development of surface replication techniques to produce the optics, fabricating the 1m glass mandrel, and constructing the optical tube assembly (OTA). Presented will be an overview and status of the 1-m mandrel fabrication, optics development, telescope design and CFRP telescope fabrication by CMA for the ULTRA Telescope.

  4. Observational Selection Effects with Ground-based Gravitational Wave Detectors

    Science.gov (United States)

    Chen, Hsin-Yu; Essick, Reed; Vitale, Salvatore; Holz, Daniel; Katsavounidis, Erik

    2017-01-01

    Ground-based interferometers are not perfectly all-sky instruments, and it is important to account for their behavior when considering the distribution of detected events. In particular, the LIGO detectors are most sensitive to sources above North America and the Indian Ocean and, as the Earth rotates, the sensitive regions are swept across the sky. However, because the detectors do not acquire data uniformly over time, there is a net bias on detectable sources' right ascensions. Both LIGO detectors preferentially collect data during their local night; it is more than twice as likely to be local midnight than noon when both detectors are operating. We discuss these selection effects and how they impact LIGO's observations and electromagnetic follow-up. These effects can inform electromagnetic follow-up activities and optimization, including the possibility of directing observations even before gravitational-wave events occur.

  5. Ground Based Synoptic Instrumentation for Solar Observations (Postprint)

    Science.gov (United States)

    2012-03-05

    None are corrected for chromatic aberration . The system overall is diffraction limited for all wavelengths in the tunable range. The magnifier lens...simultaneously corrects for chromatic focus effects and maintains a constant solar diameter throughout the year. The magnifier lens is interchangeable

  6. Instrumentation

    Energy Technology Data Exchange (ETDEWEB)

    Decreton, M

    2001-04-01

    SCK-CEN's research and development programme on instrumentation involves the assessment and the development of sensitive measurement systems used within a radiation environment. Particular emphasis is on the assessment of optical fibre components and their adaptability to radiation environments. The evaluation of ageing processes of instrumentation in fission plants, the development of specific data evaluation strategies to compensate for ageing induced degradation of sensors and cable performance form part of these activities. In 2000, particular emphasis was on in-core reactor instrumentation applied to fusion, accelerator driven and water-cooled fission reactors. This involved the development of high performance instrumentation for irradiation experiments in the BR2 reactor in support of new instrumentation needs for MYRRHA, and for diagnostic systems for the ITER reactor.

  7. Ground-based remote sensing scheme for monitoring aerosol–cloud interactions (discussion)

    NARCIS (Netherlands)

    Sarna, K.; Russchenberg, H.W.J.

    2015-01-01

    A method for continuous observation of aerosol–cloud interactions with ground-based remote sensing instruments is presented. The main goal of this method is to enable the monitoring of cloud microphysical changes due to the changing aerosol concentration. We use high resolution measurements from lid

  8. Ground-based remote sensing scheme for monitoring aerosol-cloud interactions

    NARCIS (Netherlands)

    Sarna, K.; Russchenberg, H.W.J.

    2016-01-01

    A new method for continuous observation of aerosol–cloud interactions with ground-based remote sensing instruments is presented. The main goal of this method is to enable the monitoring of the change of the cloud droplet size due to the change in the aerosol concentration. We use high-resolution mea

  9. Instrumentation

    Energy Technology Data Exchange (ETDEWEB)

    Decreton, M

    2002-04-01

    SCK-CEN's R and D programme on instrumentation involves the development of advanced instrumentation systems for nuclear applications as well as the assessment of the performance of these instruments in a radiation environment. Particular emphasis is on the use of optical fibres as umbilincal links of a remote handling unit for use during maintanance of a fusion reacor, studies on the radiation hardening of plasma diagnostic systems; investigations on new instrumentation for the future MYRRHA accelerator driven system; space applications related to radiation-hardened lenses; the development of new approaches for dose, temperature and strain measurements; the assessment of radiation-hardened sensors and motors for remote handling tasks and studies of dose measurement systems including the use of optical fibres. Progress and achievements in these areas for 2001 are described.

  10. Instrumentation

    Energy Technology Data Exchange (ETDEWEB)

    Decreton, M

    2000-07-01

    SCK-CEN's research and development programme on instrumentation aims at evaluating the potentials of new instrumentation technologies under the severe constraints of a nuclear application. It focuses on the tolerance of sensors to high radiation doses, including optical fibre sensors, and on the related intelligent data processing needed to cope with the nuclear constraints. Main achievements in these domains in 1999 are summarised.

  11. Intercomparison of ground-based ozone and NO2 measurements during the MANTRA 2004 campaign

    Directory of Open Access Journals (Sweden)

    K. Strong

    2007-11-01

    Full Text Available The MANTRA (Middle Atmosphere Nitrogen TRend Assessment 2004 campaign took place in Vanscoy, Saskatchewan, Canada (52° N, 107° W from 3 August to 15 September, 2004. In support of the main balloon launch, a suite of five zenith-sky and direct-Sun-viewing UV-visible ground-based spectrometers was deployed, primarily measuring ozone and NO2 total columns. Three Fourier transform spectrometers (FTSs that were part of the balloon payload also performed ground-based measurements of several species, including ozone. Ground-based measurements of ozone and NO2 differential slant column densities from the zenith-viewing UV-visible instruments are presented herein. They are found to partially agree within NDACC (Network for the Detection of Atmospheric Composition Change standards for instruments certified for process studies and satellite validation. Vertical column densities of ozone from the zenith-sky UV-visible instruments, the FTSs, a Brewer spectrophotometer, and ozonesondes are compared, and found to agree within the combined error estimates of the instruments (15%. NO2 vertical column densities from two of the UV-visible instruments are compared, and are also found to agree within combined error (15%.

  12. Titan Ground Complex Permittivity at the HUYGENS Landing Site; the PWA-HASI and Other Instruments Data Revisited

    Science.gov (United States)

    Hamelin, M.; Lethuillier, A.; Le Gall, A. A.; Grard, R.; Ciarletti, V.; Béghin, C.; Schwingenschuh, K.; Lorenz, R. D.; Lopez-Moreno, J. J.; Jernej, I.; Brown, V.; Ferri, F.

    2014-12-01

    Ten years after the successful landing of the HUYGENS probe on the surface of Titan, we reassess the complex permittivity measurements of the surface materials performed by the PWA-HASI experiment (Permittivity, Waves and Altimetry - Huygens Atmospheric Structure Instrument). The complex permittivity is inferred from the mutual impedance of a classical quadrupolar probe, ie. the ratio of the voltage measured by a receiving dipole over the current emitted by another dipole. Using a simple model of the quadrupole configuration, the dielectric constant of the material at the landing site was first estimated to be of the order of 1.8. A more realistic numerical model that took into account the influence of the HUYGENS gondola yielded a dielectric constant in the range 2-3 and a conductivity in the range 0.4 - 0.8 nS/m. due to uncertainties about the system geometry ( Grard et al., 2006). However, a puzzling experimental fact remains to be explained, namely a sudden variation of the amplitude and phase of the received voltage 11 mn after landing that cannot be associated with any lander mechanical disturbance. Permittivity estimations were based on the first 11 mn sequence. The present analysis takes advantage of a recent analysis of the landing process that provided more realistic final position and attitude for the HUYGENS lander (Schroder et al., 2012). The new results lie within former estimated ranges and attention is paid to their sensitivity to geometry and to the reference measurements collected immediately before landing. This point is particularly critical for the estimation of the conductivity. The complete data set has been analysed, including the sequence collected after the first 11 mn. We consider various scenarios that may explain the observed phase and amplitude discontinuity. We tested two layers ground models in order to investigate the possibility that the upper layer may have experienced a fast physical change due to deliquescence or outgasing

  13. Simultaneous ground- and satellite-based observation of MF/HF auroral radio emissions

    Science.gov (United States)

    Sato, Yuka; Kumamoto, Atsushi; Katoh, Yuto; Shinbori, Atsuki; Kadokura, Akira; Ogawa, Yasunobu

    2016-05-01

    We report on the first simultaneous measurements of medium-high frequency (MF/HF) auroral radio emissions (above 1 MHz) by ground- and satellite-based instruments. Observational data were obtained by the ground-based passive receivers in Iceland and Svalbard, and by the Plasma Waves and Sounder experiment (PWS) mounted on the Akebono satellite. We observed two simultaneous appearance events, during which the frequencies of the auroral roar and MF bursts detected at ground level were different from those of the terrestrial hectometric radiation (THR) observed by the Akebono satellite passing over the ground-based stations. This frequency difference confirms that auroral roar and THR are generated at different altitudes across the F peak. We did not observe any simultaneous observations that indicated an identical generation region of auroral roar and THR. In most cases, MF/HF auroral radio emissions were observed only by the ground-based detector, or by the satellite-based detector, even when the satellite was passing directly over the ground-based stations. A higher detection rate was observed from space than from ground level. This can primarily be explained in terms of the idea that the Akebono satellite can detect THR emissions coming from a wider region, and because a considerable portion of auroral radio emissions generated in the bottomside F region are masked by ionospheric absorption and screening in the D/E regions associated with ionization which results from auroral electrons and solar UV radiation.

  14. Market-based instruments for environmental management: politics and institutions

    DEFF Research Database (Denmark)

    The contributors examine the role of political processes in designing, introducing and implementing green taxes and charges and analyse the extent to which political concerns complicate the approach favoured by environmental economists. The authors then focus on the implementation of market......-based instruments to achieve environmental objectives and offer an ex-post evaluation of different countries’ experiences with economic instruments....

  15. Instruments

    Energy Technology Data Exchange (ETDEWEB)

    Buehrer, W. [Paul Scherrer Inst. (PSI), Villigen (Switzerland)

    1996-12-31

    The present paper mediates a basic knowledge of the most commonly used experimental techniques. We discuss the principles and concepts necessary to understand what one is doing if one performs an experiment on a certain instrument. (author) 29 figs., 1 tab., refs.

  16. Instrumentation

    Institute of Scientific and Technical Information of China (English)

    2015-01-01

    Journal Scope:Instrumentation is a high quality open access peer reviewed research journal,Authors are solicited to contribute to these journals by submitting articles that illustrate most up-to-date research results,projects,surveying works and industrial

  17. Fast, real-time, DFT instrument based on VMEbus

    Science.gov (United States)

    Snell, Jay

    An emerging class of VMEbus-based test and measurement instruments is benchmarked by a recently introduced digital spectrum analyzer. The instrument performs real-time spectrum analysis in the DC-to-10 MHz range at 5000 spectrums per second. Its architecture is based on the VMEbus and is partly adapted for high-speed pipeline processing. The keyboard and color graphic displays suit basic spectrum analysis, as well as advanced analysis of amplitude vs. both frequency and time. The instrument provides a DSP (digital signal processing) programming environment when an RS232 terminal is attached. With addition of an RF spectrum analyzer, downconverter, and software, real-time analysis is extended to 21 GHz and beyond. Postprocessable spectral output makes the instrument suitable for use in a larger signal analysis or test system. This digital spectrum analyzer, which has 17 boards on the bus, is representative of an emerging class of filled-enclosure instruments.

  18. TOMS and Ground-based Measurements: Long-term Trends, Spatial Variability, Cloud Effects, and Data Quality.

    Science.gov (United States)

    Eide, H. A.; Dahlback, A.; Stamnes, K.; Høyskar, B.; Olsen, R.; Schmidlin, F.; Tsay, S.

    2003-12-01

    Ground-based measurements and TOMS measurements are mutually beneficial to each other. Ground-based measurements of UV radiation and total column ozone amounts are important for the validation of TOMS measurements. For example, it has been shown that TOMS measurements has a tendency to under-estimate ground UV exposure. Some of these effects can perhaps be ascribed to local cloud effects or choice of ozone profiles in the retrieval algorithm. More ground-based measurements are needed to establish the cause of these discrepancies. Recent technology advances have made ground-based measurements of UV doses and ozone column amounts with inexpensive multi-channel filter instruments not only possible, but also an attractive alternative to other more labor-intensive and weather dependent methods. Filter instruments can operate unattended for long periods of time, and it is possible to obtain accurate ozone column amounts even on cloudy days. We present results from extensive comparisons of the performance of several ground-based instruments (the NILU-UV and GUV filter instruments, as well as the Dobson and Brewer instruments) against the EP-TOMS instrument. The data used in the comparisons are from three different sites where we have had the opportunity to operate more than one type of UV instruments for extended periods of time. The sites include the University of Oslo, Norway, the NASA Goddard Space Flight Center facilities at Wallops Island, VA, and Greenbelt, MD and the University of Alaska, Fairbanks (during the TOMS3F campaign). Our results show that ozone column amounts obtained with current filter-type instruments are just as good as those obtained with the Dobson instrument, and might even out-perform the Dobson instrument on cloudy days. The TOMS measurements are shown to exhibit some more variability, but there is on average very good agreement with the ground- based measurements even for high solar zenith angles (SZA). Further more, our comparison shows that

  19. Calibration Base Lines for Electronic Distance Measuring Instruments (EDMI)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — A calibration base line (CBL) is a precisely measured, straight-line course of approximately 1,400 m used to calibrate Electronic Distance Measuring Instruments...

  20. Ground-based observations of Kepler asteroseismic targets

    DEFF Research Database (Denmark)

    Uyttterhoeven , K.; Karoff, Christoffer

    2010-01-01

    We present the ground-based activities within the different working groups of the Kepler Asteroseismic Science Consortium (KASC). The activities aim at the systematic characterization of the 5000+ KASC targets, and at the collection of ground-based follow-up time-series data of selected promising...

  1. Power Gating Based Ground Bounce Noise Reduction

    Directory of Open Access Journals (Sweden)

    M. Uma Maheswari

    2014-08-01

    Full Text Available As low power circuits are most popular the decrease in supply voltage leads to increase in leakage power with respect to the technology scaling. So for removing this kind of leakages and to provide a better power efficiency many power gating techniques are used. But the leakage due to ground connection to the active part of the circuit is very high rather than all other leakages. As it is mainly due to the back EMF of the ground connection it was called it as ground bounce noise. To reduce this noise different methodologies are designed. In this paper the design of such an efficient technique related to ground bounce noise reduction using power gating circuits and comparing the results using DSCH and Microwind low power tools. In this paper the analysis of adders such as full adders using different types of power gated circuits using low power VLSI design techniques and to present the comparison results between different power gating methods.

  2. Movable Ground Based Recovery System for Reuseable Space Flight Hardware

    Science.gov (United States)

    Sarver, George L. (Inventor)

    2013-01-01

    A reusable space flight launch system is configured to eliminate complex descent and landing systems from the space flight hardware and move them to maneuverable ground based systems. Precision landing of the reusable space flight hardware is enabled using a simple, light weight aerodynamic device on board the flight hardware such as a parachute, and one or more translating ground based vehicles such as a hovercraft that include active speed, orientation and directional control. The ground based vehicle maneuvers itself into position beneath the descending flight hardware, matching its speed and direction and captures the flight hardware. The ground based vehicle will contain propulsion, command and GN&C functionality as well as space flight hardware landing cushioning and retaining hardware. The ground based vehicle propulsion system enables longitudinal and transverse maneuverability independent of its physical heading.

  3. Avoidance-based human Pavlovian-to-instrumental transfer.

    Science.gov (United States)

    Lewis, Andrea H; Niznikiewicz, Michael A; Delamater, Andrew R; Delgado, Mauricio R

    2013-12-01

    The Pavlovian-to-instrumental transfer (PIT) paradigm probes the influence of Pavlovian cues over instrumentally learned behavior. The paradigm has been used extensively to probe basic cognitive and motivational processes in studies of animal learning. More recently, PIT and its underlying neural basis have been extended to investigations in humans. These initial neuroimaging studies of PIT have focused on the influence of appetitively conditioned stimuli on instrumental responses maintained by positive reinforcement, and highlight the involvement of the striatum. In the current study, we sought to understand the neural correlates of PIT in an aversive Pavlovian learning situation when instrumental responding was maintained through negative reinforcement. Participants exhibited specific PIT, wherein selective increases in instrumental responding to conditioned stimuli occurred when the stimulus signaled a specific aversive outcome whose omission negatively reinforced the instrumental response. Additionally, a general PIT effect was observed such that when a stimulus was associated with a different aversive outcome than was used to negatively reinforce instrumental behavior, the presence of that stimulus caused a non-selective increase in overall instrumental responding. Both specific and general PIT behavioral effects correlated with increased activation in corticostriatal circuitry, particularly in the striatum, a region involved in cognitive and motivational processes. These results suggest that avoidance-based PIT utilizes a similar neural mechanism to that seen with PIT in an appetitive context, which has implications for understanding mechanisms of drug-seeking behavior during addiction and relapse.

  4. Validation of Aura OMI by Aircraft and Ground-Based Measurements

    Science.gov (United States)

    McPeters, R. D.; Petropavlovskikh, I.; Kroon, M.

    2006-12-01

    Both aircraft-based and ground-based measurements have been used to validate ozone measurements by the OMI instrument on Aura. Three Aura Validation Experiment (AVE) flights have been conducted, in November 2004 and June 2005 with the NASA WB57, and in January/February 2005 with the NASA DC-8. On these flights, validation of OMI was primarily done using data from the CAFS (CCD Actinic Flux Spectroradiometer) instrument, which is used to measure total column ozone above the aircraft. These measurements are used to differentiate changes in stratospheric ozone from changes in total column ozone. Also, changes in ozone over high clouds measured by OMI were checked in a flight over tropical storm Arlene on a flight on June 11th. Ground-based measurements were made during the SAUNA campaign in Sodankyla, Finland, in March and April 2006. Both total column ozone and the ozone vertical distribution were validated.

  5. Estimation of above ground biomass in boreal forest using ground-based Lidar

    Science.gov (United States)

    Taheriazad, L.; Moghadas, H.; Sanchez-Azofeifa, A.

    2017-05-01

    Assessing above ground biomass of forest is important for carbon storage monitoring in boreal forest. In this study, a new model is developed to estimate the above ground biomass using ground based Lidar data. 21 trees were measured and scanned across the plot area study in boreal forests of Alberta, Canada. The study area was scanned in the summer season 2014 to quantify the green biomass. The average of total crown biomass and green biomass in this study was 377 kg (standard deviation, S.D. = 243 kg) and 6.42 kg (S.D. = 2.69 m), respectively.

  6. Ka-band bistatic ground-based SAR using noise signals

    Science.gov (United States)

    Lukin, K.; Mogyla, A.; Vyplavin, P.; Palamarchuk, V.; Zemlyaniy, O.; Tarasenko, V.; Zaets, N.; Skretsanov, V.; Shubniy, A.; Glamazdin, V.; Natarov, M.; Nechayev, O.

    2008-01-01

    Currently, one of the actual problems is remote monitoring of technical state of large objects. Different methods can be used for that purpose. The most promising of them relies on application of ground based synthetic aperture radars (SAR) and differential interferometry. We have designed and tested Ground Based Noise Waveform SAR based on noise radar technology [1] and synthetic aperture antennas [2]. It enabled to build an instrument for precise all-weather monitoring of large objects in real-time. We describe main performance of ground-based interferometric SAR which uses continuous Ka-band noise waveform as a probe signal. Besides, results of laboratory trials and evaluation of its main performance are presented as well.

  7. Calibration of Nacelle-based Lidar instrument

    DEFF Research Database (Denmark)

    Yordanova, Ginka; Courtney, Michael

    This report presents the result of the lidar calibration performed for a two-beam nacelle based lidar at DTU’s test site for large wind turbines at Høvsøre, Denmark. Calibration is here understood as the establishment of a relation between the reference wind speed measurements with measurement...... uncertainties provided by measurement standard and corresponding lidar wind speed indications with associated measurement uncertainties. The lidar calibration concerns the 10 minute mean wind speed measurements....

  8. Calibration of Nacelle-based Lidar instrument

    DEFF Research Database (Denmark)

    Georgieva Yankova, Ginka; Courtney, Michael

    This report presents the result of the lidar calibration performed for a four-beam nacelle based lidar at DTU’s test site for large wind turbines at Høvsøre, Denmark.Denmark. Calibration is here understood as the establishment of a relation between the reference wind speed measurements...... with measurement uncertainties provided by measurement standard and corresponding lidar wind speed indications with associated measurement uncertainties. The lidar calibration concerns the 10 minute mean wind speed measurements....

  9. NO2 DOAS measurements from ground and space: comparison of ground based measurements and OMI data in Mexico City

    Science.gov (United States)

    Rivera, C.; Stremme, W.; Grutter, M.

    2012-04-01

    The combination of satellite data and ground based measurements can provide valuable information about atmospheric chemistry and air quality. In this work we present a comparison between measured ground based NO2 differential columns at the Universidad Nacional Autónoma de México (UNAM) in Mexico City, using the Differential Optical Absorption Spectroscopy (DOAS) technique and NO2 total columns measured by the Ozone Monitoring Instrument (OMI) onboard the Aura satellite using the same measurement technique. From these data, distribution maps of average NO2 above the Mexico basin were constructed and hot spots inside the city could be identified. In addition, a clear footprint was detected from the Tula industrial area, ~50 km northwest of Mexico City, where a refinery, a power plant and other industries are located. A less defined footprint was identified in the Cuernavaca basin, South of Mexico City, and the nearby cities of Toluca and Puebla do not present strong enhancements in the NO2 total columns. With this study we expect to cross-validate space and ground measurements and provide useful information for future studies.

  10. Realization of OFCC based Transimpedance Mode Instrumentation Amplifier

    Directory of Open Access Journals (Sweden)

    Neeta Pandey

    2016-01-01

    Full Text Available The paper presents an instrumentation amplifier suitable for amplifying the current source transducer signals. It provides a voltage output. It has a high gain, common mode rejection ratio and gain independent bandwidth. It uses three Operational Floating Current Conveyors (OFCCs and four resistors. The effect of nonidealities of OFCC on performance of proposed transimpedance instrumentation amplifier (TIA is also analyzed. The proposal has been verified through SPICE simulations using CMOS based schematicThe paper presents an instrumentation amplifier suitable for amplifying the current source transducer signals. It provides a voltage output. It has a high gain, common mode rejection ratio and gain independent bandwidth. It uses three operational floating current conveyors (OFCCs and four resistors. The effect of nonidealities of OFCC on performance of proposed transimpedance instrumentation amplifier (TIA is also analyzed. The proposal has been verified through SPICE simulations using CMOS based schematic.

  11. Endoscopic vision-based tracking of multiple surgical instruments during robot-assisted surgery.

    Science.gov (United States)

    Ryu, Jiwon; Choi, Jaesoon; Kim, Hee Chan

    2013-01-01

    Robot-assisted minimally invasive surgery is effective for operations in limited space. Enhancing safety based on automatic tracking of surgical instrument position to prevent inadvertent harmful events such as tissue perforation or instrument collisions could be a meaningful augmentation to current robotic surgical systems. A vision-based instrument tracking scheme as a core algorithm to implement such functions was developed in this study. An automatic tracking scheme is proposed as a chain of computer vision techniques, including classification of metallic properties using k-means clustering and instrument movement tracking using similarity measures, Euclidean distance calculations, and a Kalman filter algorithm. The implemented system showed satisfactory performance in tests using actual robot-assisted surgery videos. Trajectory comparisons of automatically detected data and ground truth data obtained by manually locating the center of mass of each instrument were used to quantitatively validate the system. Instruments and collisions could be well tracked through the proposed methods. The developed collision warning system could provide valuable information to clinicians for safer procedures.

  12. Safeguards instrumentation: a computer-based catalog

    Energy Technology Data Exchange (ETDEWEB)

    Fishbone, L.G.; Keisch, B.

    1981-08-01

    The information contained in this catalog is needed to provide a data base for safeguards studies and to help establish criteria and procedures for international safeguards for nuclear materials and facilities. The catalog primarily presents information on new safeguards equipment. It also describes entire safeguards systems for certain facilities, but it does not describe the inspection procedures. Because IAEA safeguards do not include physical security, devices for physical protection (as opposed to containment and surveillance) are not included. An attempt has been made to list capital costs, annual maintenance costs, replacement costs, and useful lifetime for the equipment. For equipment which is commercially available, representative sources have been listed whenever available.

  13. A Sphere-Scanning Radiometer for Rapid Directional Measurements of Sky and Ground Radiance: the PARABOLA Field Instrument

    Science.gov (United States)

    Deering, D. W.; Leone, P.

    1984-01-01

    A unique field instrument, called the PARABOLA, a collapsable support boom, which is self contained and easily transportable to remote sites to enable the acquisition of radiance data for almost the complete (4 pi) sky and ground-looking hemispheres in only 11 seconds was designed. The PARABOLA samples in 15 deg instantaneous field of view sectors in three narrow bandpass spectral channels simultaneously. Field measurement on a variety of earth surface cover types using a truck boom, a specially designed pickup truck mounting system, and a hot air balloon were studied. The PARABOLA instrument has potential for climatological and other studies which require characterization of the distribution of diffuse solar radiation within the sky hemisphere.

  14. Ground tests of the Dynamic Albedo of Neutron instrument operation in the passive mode with a Martian soil model

    Science.gov (United States)

    Shvetsov, V. N.; Dubasov, P. V.; Golovin, D. V.; Kozyrev, A. S.; Krylov, A. R.; Krylov, V. A.; Litvak, M. L.; Malakhov, A. V.; Mitrofanov, I. G.; Mokrousov, M. I.; Sanin, A. B.; Timoshenko, G. N.; Vostrukhin, A. A.; Zontikov, A. O.

    2017-07-01

    The results of the Dynamic Albedo of Neutrons (DAN) instrument ground tests in the passive mode of operation are presented in comparison with the numerical calculations. These test series were conducted to support the current surface measurements of DAN onboard the MSL Curiosity rover. The instrument sensitivity to detect thin subsurface layers of water ice buried at different depths in the analog of Martian soil has been evaluated during these tests. The experiments have been done with a radioisotope Pu-Be neutron source (analog of the MMRTG neutron source onboard the Curiosity rover) and the Martian soil model assembled from silicon-rich window glass pane. Water ice layers were simulated with polyethylene sheets. All experiments have been performed at the test facility built at the Joint Institute for Nuclear Research (Dubna, Russia).

  15. Evaluation of instrumented shoes for ambulatory assessment of ground reaction forces

    NARCIS (Netherlands)

    Liedtke, Christian; Fokkenrood, Steven A.W.; Menger, Jasper T.; Kooij, van der Herman; Veltink, Peter H.

    2007-01-01

    Currently, force plates or pressure sensitive insoles are the standard tools to measure ground reaction forces and centre of pressure data during human gait. Force plates, however, impose constraints on foot placement, and the available pressure sensitive insoles measure only one component of force.

  16. Which future for electromagnetic Astronomy: Ground Based vs Space Borne Large Astrophysical Facilities

    Science.gov (United States)

    Ubertini, Pietro

    2015-08-01

    The combined use of large ground based facilities and large space observatories is playing a key role in the advance of astrophysics by providing access to the entire electromagnetic spectrum, allowing high sensitivity observations from the lower radio wavelength to the higher energy gamma rays.It is nowadays clear that a forward steps in the understanding of the Universe evolution and large scale structure formation is essential and only possible with the combined use of multiwavelength imaging and spectral high resolution instruments.The increasing size, complexity and cost of large ground and space observatories places a growing emphasis on international collaboration. If the present set of astronomical facilities is impressive and complete, with nicely complementary space and ground based telescopes, the scenario becomes worrisome and critical in the next two decades. In fact, only a few ‘Large’ main space missions are planned and there is a need to ensure proper ground facility coverage: the synergy Ground-Space is not escapable in the timeframe 2020-2030.The scope of this talk is to review the current astronomical instrumentation panorama also in view of the recent major national agencies and international bodies programmatic decisions.This Division B meeting give us a unique opportunity to review the current situation and discuss the future perspectives taking advantage of the large audience ensured by the IAU GA.

  17. Coordinated Ground- and Space-based Multispectral Campaign to Study Equatorial Spread-F Formation

    Science.gov (United States)

    Finn, S. C.; Geddes, G.; Aryal, S.; Stephan, A. W.; Budzien, S. A.; Duggirala, P. R.; Chakrabarti, S.; Valladares, C.

    2016-12-01

    We present a concept for a multispectral campaign using coordinated data from state-of-the-art instruments aboard the International Space Station (ISS) and multiple ground-based spectrometers and digisondes deployed at low-latitudes to study the formation and development of Equatorial Spread-F (ESF). This extended observational campaign utilizes ultraviolet, visible, and radio measurements to develop a predictive capability for ESF and to study the coupling of the ionosphere-thermosphere (I-T) system during geomagnetically quiet and disturbed times. The ground-based instruments will be deployed in carefully chosen locations in the American and Indian sectors while the space-based data will provide global coverage spanning all local times and longitudes within ±51° geographic latitudes. The campaign, over an extended period covering a range of geophysical conditions, will provide the extensive data base necessary to address the important science questions. The space-based instrument suite consists of the Limb-imaging Ionospheric and Thermospheric Extreme-ultraviolet Spectrograph (LITES) and the GPS Radio Occultation and Ultraviolet Photometry-Colocated (GROUP-C) instruments, scheduled to launch to the ISS in November 2016. LITES is a compact imaging spectrograph for remote sensing of the upper atmosphere and ionosphere from 60 to 140nm and GROUP-C has a nadir-viewing FUV photometer. The ground-based instruments to be deployed for this campaign are three high-resolution imaging spectrographs capable of continuous round-the-clock airglow observations: Multiwavelength Imaging Spectrograph using Echelle grating (MISE) in India and two High Throughput and Multi-slit Imaging Spectrographs (HiT&MIS) to be deployed in Colombia and Argentina, the Low-Latitude Ionosphere Sensor Network (LISN), and the Global Ionospheric Radio Observatory (GIRO) digisondes network. We present data from the ground-based instruments, initial results from the LITES and GROUP-C instruments on

  18. Ground-based Remote Sensing of Cloud Liquid Water Path

    Science.gov (United States)

    Crewell, S.; Loehnert, U.

    Within the BALTEX Cloud LIquid WAter NETwork (CLIWA-NET) measurements of cloud parameters were performed to improve/evaluate cloud parameterizations in numerical weather prediction and climate models. The key variable is the cloud liq- uid water path (LWP) which is measured by passive microwave radiometry from the ground during three two-month CLIWA-NET observational periods. Additionally to the high temporal resolution time series from the ground, LWP fields are derived from satellite measurements. During the first two campaigns a continental scale network consisting of 12 stations was established. Most stations included further cloud sen- sitive instruments like infrared radiometer and lidar ceilometer. The third campaign started with a two-week long microwave intercomparison campaign (MICAM) in Cabauw, The Netherlands, and proceeded with a regional network within a 100 by 100 km area. The presentation will focus on the accuracy of LWP derived from the ground by in- vestigating the accuracy of the microwave brightness temperature measurement and examining the LWP retrieval uncertainty. Up to now microwave radiometer are no standard instruments and the seven radiometer involved in MICAM differ in frequen- cies, bandwidths, angular resolution, integration time etc. The influence of this instru- ment specifications on the LWP retrieval will be discussed.

  19. HelixFlex: bioinspired maneuverable instrument for skull base surgery.

    Science.gov (United States)

    Gerboni, Giada; Henselmans, Paul W J; Arkenbout, Ewout A; van Furth, Wouter R; Breedveld, Paul

    2015-12-01

    Endoscopic endonasal surgery is currently regarded as the 'gold standard' for operating on pituitary gland tumors, and is becoming more and more accepted for treatment of other skull base lesions. However, endoscopic surgical treatment of most skull base pathologies, including certain pituitary tumors, is severely impaired by current instruments lack of maneuverability. Especially, gaining access to, and visibility of, difficult-to-reach anatomical corners without interference with surrounding neurovascular structures or other instruments, is a challenge. In this context there is the need for instruments that are able to provide a stable shaft position, while both the orientation and the position of the end-effector can be independently controlled. Current instruments that allow for this level of maneuverability are usually mechanically complex, and hence less suitable for mass production. This study therefore focuses on the development of a new actuation technique that allows for the required maneuverability while reducing the construction complexity. This actuation technique, referred to as multi-actuation, integrates multiple cable routings into a single steerable structure. Multi-actuation has been successfully integrated and tested in a handheld prototype instrument called HelixFlex. HelixFlex contains a 4 degrees of freedom maneuverable 5.8 mm (diameter) tip and shows promising results concerning its maneuverability and potential rigidity.

  20. Lifetime-based portable instrument for blood gas analysis

    Science.gov (United States)

    Kieslinger, Dietmar; Trznadel, Karolina; Oechs, Karin; Draxler, Sonja; Lippitsch, Max E.

    1997-06-01

    A portable, compact device for measuring blood gases by using the fluorescence decay time as the information carrier is presented. The instrument is based on solid state technology only, thus using LEDs for excitation and a photodiode as detector. A capillary coated on its inner surface with different sensing membranes serves as a sample compartment and an optical sensor element simultaneously. Furthermore, due to inhomogeneous waveguiding in the capillary walls, only the fluorescent light is guided. Technical details of the electronic circuit, the optical design and the instrumental performance will be discussed.

  1. Validation of Atmosphere/Ionosphere Signals Associated with Major Earthquakes by Multi-Instrument Space-Borne and Ground Observations

    Science.gov (United States)

    Ouzounov, Dimitar; Pulinets, Sergey; Hattori, Katsumi; Parrot, Michel; Liu, J. Y.; Yang, T. F.; Arellano-Baeza, Alonso; Kafatos, M.; Taylor, Patrick

    2012-01-01

    regions of the atmosphere and the modifications, by dc electric fields, in the ionosphere-atmosphere electric circuit. We retrospectively analyzed temporal and spatial variations of four different physical parameters (gas/radon counting rate, lineaments change, long-wave radiation transitions and ionospheric electron density/plasma variations) characterizing the state of the lithosphere/atmosphere coupling several days before the onset of the earthquakes. Validation processes consist in two phases: A. Case studies for seven recent major earthquakes: Japan (M9.0, 2011), China (M7.9, 2008), Italy (M6.3, 2009), Samoa (M7, 2009), Haiti (M7.0, 2010) and, Chile (M8.8, 2010) and B. A continuous retrospective analysis was preformed over two different regions with high seismicity- Taiwan and Japan for 2003-2009. Satellite, ground surface, and troposphere data were obtained from Terra/ASTER, Aqua/AIRS, POES and ionospheric variations from DEMETER and COSMIC-I data. Radon and GPS/TEC were obtaining from monitoring sites in Taiwan, Japan and Italy and from global ionosphere maps (GIM) respectively. Our analysis of ground and satellite data during the occurrence of 7 global earthquakes has shown the presence of anomalies in the atmosphere. Our results for Tohoku M9.0 earthquake show that on March 7th, 2011 (4 days before the main shock and 1 day before the M7.2 foreshock of March 8, 2011) a rapid increase of emitted infrared radiation was observed by the satellite data and an anomaly was developed near the epicenter. The GPS/TEC data indicate an increase and variation in electron density reaching a maximum value on March 8. From March 3 to 11 a large increase in electron concentration was recorded at all four Japanese ground-based ionosondes, which returned to normal after the main earthquake. Similar approach for analyzing atmospheric and ionospheric parameters has been applied for China (M7.9, 2008), Italy (M6.3, 2009), Samoa (M7, 2009), Haiti (M7.0, 2010) and Chile (M8.8, 2010

  2. Observational Selection Effects with Ground-based Gravitational Wave Detectors

    Science.gov (United States)

    Chen, Hsin-Yu; Essick, Reed; Vitale, Salvatore; Holz, Daniel E.; Katsavounidis, Erik

    2017-01-01

    Ground-based interferometers are not perfect all-sky instruments, and it is important to account for their behavior when considering the distribution of detected events. In particular, the LIGO detectors are most sensitive to sources above North America and the Indian Ocean, and as the Earth rotates, the sensitive regions are swept across the sky. However, because the detectors do not acquire data uniformly over time, there is a net bias on detectable sources’ right ascensions. Both LIGO detectors preferentially collect data during their local night; it is more than twice as likely to be local midnight than noon when both detectors are operating. We discuss these selection effects and how they impact LIGO’s observations and electromagnetic (EM) follow-up. Beyond galactic foregrounds associated with seasonal variations, we find that equatorial observatories can access over 80% of the localization probability, while mid-latitudes will access closer to 70%. Facilities located near the two LIGO sites can observe sources closer to their zenith than their analogs in the south, but the average observation will still be no closer than 44° from zenith. We also find that observatories in Africa or the South Atlantic will wait systematically longer before they can begin observing compared to the rest of the world though, there is a preference for longitudes near the LIGOs. These effects, along with knowledge of the LIGO antenna pattern, can inform EM follow-up activities and optimization, including the possibility of directing observations even before gravitational-wave events occur.

  3. Ozone profiles above Kiruna from two ground-based radiometers

    Science.gov (United States)

    Ryan, Niall J.; Walker, Kaley A.; Raffalski, Uwe; Kivi, Rigel; Gross, Jochen; Manney, Gloria L.

    2016-09-01

    This paper presents new atmospheric ozone concentration profiles retrieved from measurements made with two ground-based millimetre-wave radiometers in Kiruna, Sweden. The instruments are the Kiruna Microwave Radiometer (KIMRA) and the Millimeter wave Radiometer 2 (MIRA 2). The ozone concentration profiles are retrieved using an optimal estimation inversion technique, and they cover an altitude range of ˜ 16-54 km, with an altitude resolution of, at best, 8 km. The KIMRA and MIRA 2 measurements are compared to each other, to measurements from balloon-borne ozonesonde measurements at Sodankylä, Finland, and to measurements made by the Microwave Limb Sounder (MLS) aboard the Aura satellite. KIMRA has a correlation of 0.82, but shows a low bias, with respect to the ozonesonde data, and MIRA 2 shows a smaller magnitude low bias and a 0.98 correlation coefficient. Both radiometers are in general agreement with each other and with MLS data, showing high correlation coefficients, but there are differences between measurements that are not explained by random errors. An oscillatory bias with a peak of approximately ±1 ppmv is identified in the KIMRA ozone profiles over an altitude range of ˜ 18-35 km, and is believed to be due to baseline wave features that are present in the spectra. A time series analysis of KIMRA ozone for winters 2008-2013 shows the existence of a local wintertime minimum in the ozone profile above Kiruna. The measurements have been ongoing at Kiruna since 2002 and late 2012 for KIMRA and MIRA 2, respectively.

  4. A Quarter Active Suspension System Based Ground-Hook Controller

    OpenAIRE

    Turnip Arjon

    2016-01-01

    An alternative design technique for active suspension system of vehicle using a developved ground-hook damping system as a reference is proposed. The controller parameters are determined using Lyapunov method and can be tuned to precisely achieve the type of desired response which given by reference model. The simulation result show that the designed active suspension system based ground-hook reference model is able to significantly improve the ride comfort and the road holding compared with ...

  5. A miniaturized ASIC-based multichannel scaler instrument

    Energy Technology Data Exchange (ETDEWEB)

    Ericson, M.N.; Turner, G.W.; McMillan, D.E.; Hoffheins, B.S.; Todd, R.A. [Oak Ridge National Lab., TN (United States); Hiller, J.M. [Oak Ridge Y-12 Plant, TN (United States)

    1993-12-31

    A miniaturized multichannel scaler instrument has been developed to address size and operational constraints for data acquisition in a portable laser-induced luminescence system. The multichannel scaling (MCS) function is implemented as a programmable application specific integrated circuit (ASIC) with standard interfaces for control and data acquisition. The instrument is microcontroller-based with sufficient computing power for data manipulation and algorithmic processing. The unit includes electronics for laser control, and amplification and pulse height discrimination of PMT pulses. Modification of the instrument should allow use in nuclear, chemical, and spectroscopy related applications including Mossbauer experiments. Interfaces are incorporated allowing both computer-controlled and stand alone operation. Implementation of the MCS function as an ASIC and comparison with conventional implementations are discussed. Full characterization of the MCS is presented including differential non-linearity (DNL), bin dead time, and bandwidth measurements.

  6. A New Power Quality Instrument Based on Raspberry-Pi

    Directory of Open Access Journals (Sweden)

    Fabio Leccese

    2016-09-01

    Full Text Available This article describes a new instrument for power quality (PQ measurements based on the Raspberry-Pi. This is the latest step of a long study started by the Electric and Electronic Measurements Laboratory of “Roma Tre” University 12 years ago. During this time, the Laboratory developed and refined instrumentation for high accuracy power quality measurements. Through its own architecture, the new instrument allows the use of the Raspberry instead of a personal computer (PC. The data acquired and locally processed are then sent to a remote server where they can be shown to users. Imagines of the system and of the data prove the activity of the system.

  7. Deep Borehole Instrumentation Along San Francisco Bay Bridges: 1996 - 2003 and Strong Ground Motion Systhesis Along the San Francisco/Oakland Bay Bridge

    Energy Technology Data Exchange (ETDEWEB)

    Hutchings, L; Foxall, W; Kasameyer, P; larsen, S; Hayek, C; Tyler-Turpin, C; Aquilino, J; Long, L

    2005-04-22

    As a result of collaboration between the Berkeley Seismographic Station, Lawrence Livermore National Laboratory, and Caltrans, instrument packages have been placed in bedrock in six boreholes and two surface sites along the San Francisco/Oakland Bay Bridge. Since 1996 over 200 local earthquakes have been recorded. Prior to this study few seismic recording instruments existed in bed-rock in San Francisco Bay. We utilized the data to perform analysis of ground motion variability, wave passage, site response, and up-and down-hole wave propagation along the Bay Bridge. We also synthesized strong ground motion at nine locations along the Bay Bridge. Key to these studies is LLNL's effort to exploit the information available in weak ground motions (generally from earthquakes < M=4.0) to enhance predictions of seismic hazards. We found that Yerba Island has no apparent site response at the surface relative to a borehole site. The horizontal to vertical spectral ratio method best revealed no site response, while the complex signal spectral ratio method had the lowest variance for spectral ratios and best predicted surface recordings when the borehole recording was used as input. Both methods identified resonances at about the same frequencies. Regional attenuation results in a significant loss of high frequencies in both surface and borehole recordings. Records are band limited at near 3 Hz. Therefore a traditional rock outcrop site response, flat to high frequency in displacement, is not available. We applied a methodology to predict and synthesize strong ground motion along the San Francisco/Oakland Bay Bridge from a M=7.25 earthquake along the Hayward fault, about12 km distant. We synthesized for three-components and broad-band (0.0-25.0 Hz) ground motion accelerations, velocities, and displacements. We examined two different possible rupture scenarios, a ''mean'' and ''one standard deviation'' model. We combined the high

  8. An instrument for measuring scintillators efficiently based on silicon photomultipliers.

    Science.gov (United States)

    Yang, M J; Zhang, Z M; Wang, Y J; Li, D W; Zhou, W; Tang, H H; Liu, Y T; Chai, P; Shuai, L; Huang, X C; Liu, S Q; Zhu, M L; Jiang, X P; Zhang, Y W; Li, T; Ma, B; Sun, S F; Sun, L Y; Wang, Q; Lu, Z R; Zhang, T; Wei, L

    2016-11-01

    An instrument used for measuring multiple scintillators' light output and energy resolution was developed. The instrument consisted of a light sensor array which was composed of 64 discrete SiPMs (Silicon Photomultipliers), a corresponding individual channel readout electronics system, and a data processing algorithm. A Teflon grid and a large interval between adjacent SiPMs were employed to eliminate the optical cross talk among scintillators. The scintillators' light output was obtained by comparing with a reference sample with known light output. Given the SiPM temperature dependency and the difference among each SiPM, a temperature offset correction algorithm and a non-uniformity correction algorithm were added to the instrument. A positioning algorithm, based on nine points, was designed to evaluate the performance of a scintillator array. Tests were performed to evaluate the instrument's performance. The uniformity of 64 channels for light output measurement was better than 98%, the stability was better than 98% when temperature varied from 15 °C to 40 °C, and the nonlinearity under 511 keV was better than 2%. This instrument was capable of selecting scintillators and evaluating the packaging technology of scintillator arrays with high efficiency and accuracy.

  9. An instrument for measuring scintillators efficiently based on silicon photomultipliers

    Science.gov (United States)

    Yang, M. J.; Zhang, Z. M.; Wang, Y. J.; Li, D. W.; Zhou, W.; Tang, H. H.; Liu, Y. T.; Chai, P.; Shuai, L.; Huang, X. C.; Liu, S. Q.; Zhu, M. L.; Jiang, X. P.; Zhang, Y. W.; Li, T.; Ma, B.; Sun, S. F.; Sun, L. Y.; Wang, Q.; Lu, Z. R.; Zhang, T.; Wei, L.

    2016-11-01

    An instrument used for measuring multiple scintillators' light output and energy resolution was developed. The instrument consisted of a light sensor array which was composed of 64 discrete SiPMs (Silicon Photomultipliers), a corresponding individual channel readout electronics system, and a data processing algorithm. A Teflon grid and a large interval between adjacent SiPMs were employed to eliminate the optical cross talk among scintillators. The scintillators' light output was obtained by comparing with a reference sample with known light output. Given the SiPM temperature dependency and the difference among each SiPM, a temperature offset correction algorithm and a non-uniformity correction algorithm were added to the instrument. A positioning algorithm, based on nine points, was designed to evaluate the performance of a scintillator array. Tests were performed to evaluate the instrument's performance. The uniformity of 64 channels for light output measurement was better than 98%, the stability was better than 98% when temperature varied from 15 °C to 40 °C, and the nonlinearity under 511 keV was better than 2%. This instrument was capable of selecting scintillators and evaluating the packaging technology of scintillator arrays with high efficiency and accuracy.

  10. Engineering uses of physics-based ground motion simulations

    Science.gov (United States)

    Baker, Jack W.; Luco, Nicolas; Abrahamson, Norman A.; Graves, Robert W.; Maechling, Phillip J.; Olsen, Kim B.

    2014-01-01

    This paper summarizes validation methodologies focused on enabling ground motion simulations to be used with confidence in engineering applications such as seismic hazard analysis and dynmaic analysis of structural and geotechnical systems. Numberical simullation of ground motion from large erthquakes, utilizing physics-based models of earthquake rupture and wave propagation, is an area of active research in the earth science community. Refinement and validatoin of these models require collaboration between earthquake scientists and engineering users, and testing/rating methodolgies for simulated ground motions to be used with confidence in engineering applications. This paper provides an introduction to this field and an overview of current research activities being coordinated by the Souther California Earthquake Center (SCEC). These activities are related both to advancing the science and computational infrastructure needed to produce ground motion simulations, as well as to engineering validation procedures. Current research areas and anticipated future achievements are also discussed.

  11. Ground-Based VIS/NIR Reflectance Spectra of 25143 Itokawa: What Hayabusa will See and How Ground-Based Data can Augment Analyses

    Science.gov (United States)

    Vilas, Faith; Abell, P. A.; Jarvis, K. S.

    2004-01-01

    Planning for the arrival of the Hayabusa spacecraft at asteroid 25143 Itokawa includes consideration of the expected spectral information to be obtained using the AMICA and NIRS instruments. The rotationally-resolved spatial coverage the asteroid we have obtained with ground-based telescopic spectrophotometry in the visible and near-infrared can be utilized here to address expected spacecraft data. We use spectrophotometry to simulate the types of data that Hayabusa will receive with the NIRS and AMICA instruments, and will demonstrate them here. The NIRS will cover a wavelength range from 0.85 m, and have a dispersion per element of 250 Angstroms. Thus, we are limited in coverage of the 1.0 micrometer and 2.0 micrometer mafic silicate absorption features. The ground-based reflectance spectra of Itokawa show a large component of olivine in its surface material, and the 2.0 micrometer feature is shallow. Determining the olivine to pyroxene abundance ratio is critically dependent on the attributes of the 1.0- and 2.0 micrometer features. With a cut-off near 2,1 micrometer the longer edge of the 2.0- feature will not be obtained by NIRS. Reflectance spectra obtained using ground-based telescopes can be used to determine the regional composition around space-based spectral observations, and possibly augment the longer wavelength spectral attributes. Similarly, the shorter wavelength end of the 1.0 micrometer absorption feature will be partially lost to the NIRS. The AMICA filters mimic the ECAS filters, and have wavelength coverage overlapping with the NIRS spectral range. We demonstrate how merging photometry from AMICA will extend the spectral coverage of the NIRS. Lessons learned from earlier spacecraft to asteroids should be considered.

  12. Laser based bi-directional Gbit ground links with the Tesat transportable adaptive optical ground station

    Science.gov (United States)

    Heine, Frank; Saucke, Karen; Troendle, Daniel; Motzigemba, Matthias; Bischl, Hermann; Elser, Dominique; Marquardt, Christoph; Henninger, Hennes; Meyer, Rolf; Richter, Ines; Sodnik, Zoran

    2017-02-01

    Optical ground stations can be an alternative to radio frequency based transmit (forward) and receive (return) systems for data relay services and other applications including direct to earth optical communications from low earth orbit spacecrafts, deep space receivers, space based quantum key distribution systems and Tbps capacity feeder links to geostationary spacecrafts. The Tesat Transportable Adaptive Optical Ground Station is operational since September 2015 at the European Space Agency site in Tenerife, Spain.. This paper reports about the results of the 2016 experimental campaigns including the characterization of the optical channel from Tenerife for an optimized coding scheme, the performance of the T-AOGS under different atmospheric conditions and the first successful measurements of the suitability of the Alphasat LCT optical downlink performance for future continuous variable quantum key distribution systems.

  13. Synchronized observations by using the STEREO and the largest ground-based decametre radio telescope

    Science.gov (United States)

    Konovalenko, A. A.; Stanislavsky, A. A.; Rucker, H. O.; Lecacheux, A.; Mann, G.; Bougeret, J.-L.; Kaiser, M. L.; Briand, C.; Zarka, P.; Abranin, E. P.; Dorovsky, V. V.; Koval, A. A.; Mel'nik, V. N.; Mukha, D. V.; Panchenko, M.

    2013-08-01

    We consider the approach to simultaneous (synchronous) solar observations of radio emission by using the STEREO-WAVES instruments (frequency range 0.125-16 MHz) and the largest ground-based low-frequency radio telescope. We illustrate it by the UTR-2 radio telescope implementation (10-30 MHz). The antenna system of the radio telescope is a T-shape-like array of broadband dipoles and is located near the village Grakovo in the Kharkiv region (Ukraine). The third observation point on the ground in addition to two space-based ones improves the space-mission performance capabilities for the determination of radio-emission source directivity. The observational results from the high sensitivity antenna UTR-2 are particularly useful for analysis of STEREO data in the condition of weak event appearances during solar activity minima. In order to improve the accuracy of flux density measurements, we also provide simultaneous observations with a large part of the UTR-2 radio telescope array and its single dipole close to the STEREO-WAVES antennas in sensitivity. This concept has been studied by comparing the STEREO data with ground-based records from 2007-2011 and shown to be effective. The capabilities will be useful in the implementation of new instruments (LOFAR, LWA, MWA, etc.) and during the future Solar Orbiter mission.

  14. Ground point filtering of UAV-based photogrammetric point clouds

    Science.gov (United States)

    Anders, Niels; Seijmonsbergen, Arie; Masselink, Rens; Keesstra, Saskia

    2016-04-01

    Unmanned Aerial Vehicles (UAVs) have proved invaluable for generating high-resolution and multi-temporal imagery. Based on photographic surveys, 3D surface reconstructions can be derived photogrammetrically so producing point clouds, orthophotos and surface models. For geomorphological or ecological applications it may be necessary to separate ground points from vegetation points. Existing filtering methods are designed for point clouds derived using other methods, e.g. laser scanning. The purpose of this paper is to test three filtering algorithms for the extraction of ground points from point clouds derived from low-altitude aerial photography. Three subareas were selected from a single flight which represent different scenarios: 1) low relief, sparsely vegetated area, 2) low relief, moderately vegetated area, 3) medium relief and moderately vegetated area. The three filtering methods are used to classify ground points in different ways, based on 1) RGB color values from training samples, 2) TIN densification as implemented in LAStools, and 3) an iterative surface lowering algorithm. Ground points are then interpolated into a digital terrain model using inverse distance weighting. The results suggest that different landscapes require different filtering methods for optimal ground point extraction. While iterative surface lowering and TIN densification are fully automated, color-based classification require fine-tuning in order to optimize the filtering results. Finally, we conclude that filtering photogrammetric point clouds could provide a cheap alternative to laser scan surveys for creating digital terrain models in sparsely vegetated areas.

  15. OFCC based voltage and transadmittance mode instrumentation amplifier

    Science.gov (United States)

    Nand, Deva; Pandey, Neeta; Pandey, Rajeshwari; Tripathi, Prateek; Gola, Prashant

    2017-07-01

    The operational floating current conveyor (OFCC) is a versatile active block due to the availability of both low and high input and output impedance terminals. This paper addresses the realization of OFCC based voltage and transadmittance mode instrumentation amplifiers (VMIA and TAM IA). It employs three OFCCs and seven resistors. The transadmittance mode operation can easily be obtained by simply connecting an OFCC based voltage to current converter at the output. The effect of non-idealities of OFCC, in particular finite transimpedance and tracking error, on system performance is also dealt with and corresponding mathematical expressions are derived. The functional verification is performed through SPICE simulation using CMOS based implementation of OFCC.

  16. Psychometric instrumentation: reliability and validity of instruments used for clinical practice, evidence-based practice projects and research studies.

    Science.gov (United States)

    Mayo, Ann M

    2015-01-01

    It is important for CNSs and other APNs to consider the reliability and validity of instruments chosen for clinical practice, evidence-based practice projects, or research studies. Psychometric testing uses specific research methods to evaluate the amount of error associated with any particular instrument. Reliability estimates explain more about how well the instrument is designed, whereas validity estimates explain more about scores that are produced by the instrument. An instrument may be architecturally sound overall (reliable), but the same instrument may not be valid. For example, if a specific group does not understand certain well-constructed items, then the instrument does not produce valid scores when used with that group. Many instrument developers may conduct reliability testing only once, yet continue validity testing in different populations over many years. All CNSs should be advocating for the use of reliable instruments that produce valid results. Clinical nurse specialists may find themselves in situations where reliability and validity estimates for some instruments that are being utilized are unknown. In such cases, CNSs should engage key stakeholders to sponsor nursing researchers to pursue this most important work.

  17. GLAST and Ground-Based Gamma-Ray Astronomy

    Science.gov (United States)

    McEnery, Julie

    2008-01-01

    The launch of the Gamma-ray Large Area Space Telescope together with the advent of a new generation of ground-based gamma-ray detectors such as VERITAS, HESS, MAGIC and CANGAROO, will usher in a new era of high-energy gamma-ray astrophysics. GLAST and the ground based gamma-ray observatories will provide highly complementary capabilities for spectral, temporal and spatial studies of high energy gamma-ray sources. Joint observations will cover a huge energy range, from 20 MeV to over 20 TeV. The LAT will survey the entire sky every three hours, allowing it both to perform uniform, long-term monitoring of variable sources and to detect flaring sources promptly. Both functions complement the high-sensitivity pointed observations provided by ground-based detectors. Finally, the large field of view of GLAST will allow a study of gamma-ray emission on large angular scales and identify interesting regions of the sky for deeper studies at higher energies. In this poster, we will discuss the science returns that might result from joint GLAST/ground-based gamma-ray observations and illustrate them with detailed source simulations.

  18. GLAST and Ground-Based Gamma-Ray Astronomy

    Science.gov (United States)

    McEnery, Julie

    2008-01-01

    The launch of the Gamma-ray Large Area Space Telescope together with the advent of a new generation of ground-based gamma-ray detectors such as VERITAS, HESS, MAGIC and CANGAROO, will usher in a new era of high-energy gamma-ray astrophysics. GLAST and the ground based gamma-ray observatories will provide highly complementary capabilities for spectral, temporal and spatial studies of high energy gamma-ray sources. Joint observations will cover a huge energy range, from 20 MeV to over 20 TeV. The LAT will survey the entire sky every three hours, allowing it both to perform uniform, long-term monitoring of variable sources and to detect flaring sources promptly. Both functions complement the high-sensitivity pointed observations provided by ground-based detectors. Finally, the large field of view of GLAST will allow a study of gamma-ray emission on large angular scales and identify interesting regions of the sky for deeper studies at higher energies. In this poster, we will discuss the science returns that might result from joint GLAST/ground-based gamma-ray observations and illustrate them with detailed source simulations.

  19. A Quarter Active Suspension System Based Ground-Hook Controller

    Directory of Open Access Journals (Sweden)

    Turnip Arjon

    2016-01-01

    Full Text Available An alternative design technique for active suspension system of vehicle using a developved ground-hook damping system as a reference is proposed. The controller parameters are determined using Lyapunov method and can be tuned to precisely achieve the type of desired response which given by reference model. The simulation result show that the designed active suspension system based ground-hook reference model is able to significantly improve the ride comfort and the road holding compared with semi-active suspension.

  20. 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.

  1. Integrated Train Ground Radio Communication System Based TD-LTE

    Institute of Scientific and Technical Information of China (English)

    ZHAO Hongli; CAO Yuan; ZHU Li; XU Wei

    2016-01-01

    In existing metro systems, the train ground radio communication system for different applications are deployed independently. Investing and constructing the communication infrastructures repeatedly wastes substan-tial social resources, and it brings difficulties to maintain all these infrastructures. We present the communication Quality of service (QoS) requirement for different train ground radio applications. An integrated TD-LTE based train ground radio communication system for the metro system (LTE-M) is designed next. In order to test the LTE-M system performance, an indoor testing environment is set up. The channel simulator and programmable attenua-tors are used to simulate the real metro environment. Ex-tensive test results show that the designed LTE-M system performance satisfies metro communication requirements.

  2. Ultrasonic wave-based structural health monitoring embedded instrument

    Energy Technology Data Exchange (ETDEWEB)

    Aranguren, G.; Monje, P. M., E-mail: pedromaria.monje@ehu.es [Electronic Design Group, Faculty of Engineering of Bilbao, University of the Basque Country, Bilbao (Spain); Cokonaj, Valerijan [AERnnova Engineering Solutions Ibérica S.A., Madrid (Spain); Barrera, Eduardo; Ruiz, Mariano [Instrumentation and Applied Acoustic Research Group of the Technical University of Madrid, Madrid (Spain)

    2013-12-15

    Piezoelectric sensors and actuators are the bridge between electronic and mechanical systems in structures. This type of sensor is a key element in the integrity monitoring of aeronautic structures, bridges, pressure vessels, wind turbine blades, and gas pipelines. In this paper, an all-in-one system for Structural Health Monitoring (SHM) based on ultrasonic waves is presented, called Phased Array Monitoring for Enhanced Life Assessment. This integrated instrument is able to generate excitation signals that are sent through piezoelectric actuators, acquire the received signals in the piezoelectric sensors, and carry out signal processing to check the health of structures. To accomplish this task, the instrument uses a piezoelectric phased-array transducer that performs the actuation and sensing of the signals. The flexibility and strength of the instrument allow the user to develop and implement a substantial part of the SHM technique using Lamb waves. The entire system is controlled using configuration software and has been validated through functional, electrical loading, mechanical loading, and thermal loading resistance tests.

  3. Ultrasonic wave-based structural health monitoring embedded instrument.

    Science.gov (United States)

    Aranguren, G; Monje, P M; Cokonaj, Valerijan; Barrera, Eduardo; Ruiz, Mariano

    2013-12-01

    Piezoelectric sensors and actuators are the bridge between electronic and mechanical systems in structures. This type of sensor is a key element in the integrity monitoring of aeronautic structures, bridges, pressure vessels, wind turbine blades, and gas pipelines. In this paper, an all-in-one system for Structural Health Monitoring (SHM) based on ultrasonic waves is presented, called Phased Array Monitoring for Enhanced Life Assessment. This integrated instrument is able to generate excitation signals that are sent through piezoelectric actuators, acquire the received signals in the piezoelectric sensors, and carry out signal processing to check the health of structures. To accomplish this task, the instrument uses a piezoelectric phased-array transducer that performs the actuation and sensing of the signals. The flexibility and strength of the instrument allow the user to develop and implement a substantial part of the SHM technique using Lamb waves. The entire system is controlled using configuration software and has been validated through functional, electrical loading, mechanical loading, and thermal loading resistance tests.

  4. Validation of middle atmospheric campaign-based water vapour measured by the ground-based microwave radiometer MIAWARA-C

    Directory of Open Access Journals (Sweden)

    B. Tschanz

    2013-02-01

    Full Text Available Middle atmospheric water vapour can be used as a tracer for dynamical processes. It is mainly measured by satellite instruments and ground-based microwave radiometers. Ground-based instruments capable of measuring middle atmospheric water vapour are sparse but valuable as they complement satellite measurements, are relatively easy to maintain and have a long lifetime. MIAWARA-C is a ground-based microwave radiometer for middle atmospheric water vapour designed for use on measurement campaigns for both atmospheric case studies and instrument intercomparisons. MIAWARA-C's retrieval version 1.1 (v1.1 is set up in a way to provide a consistent data set even if the instrument is operated from different locations on a campaign basis. The sensitive altitude range for v1.1 extends from 4 hPa (37 km to 0.017 hPa (75 km. MIAWARA-C measures two polarisations of the incident radiation in separate receiver channels and can therefore provide two independent measurements of the same air mass. The standard deviation of the difference between the profiles obtained from the two polarisations is in excellent agreement with the estimated random error of v1.1. In this paper, the quality of v1.1 data is assessed during two measurement campaigns: (1 five months of measurements in the Arctic (Sodankylä, 67.37° N/26.63° E and (2 nine months of measurements at mid-latitudes (Zimmerwald, 46.88° N/7.46° E. For both campaigns MIAWARA-C's profiles are compared to measurements from the satellite experiments Aura MLS and MIPAS. In addition, comparisons to ACE-FTS and SOFIE are presented for the Arctic and to the ground-based radiometer MIAWARA for the mid-latitudinal campaign. In general all intercomparisons show high correlation coefficients, above 0.5 at altitudes above 45 km, confirming the ability of MIAWARA-C to monitor temporal variations on the order of days. The biases are generally below 10% and within the estimated systematic uncertainty of MIAWARA-C. No

  5. Systematic review of the psychometric properties and theoretical grounding of instruments evaluating self-care in people with type 2 diabetes mellitus.

    Science.gov (United States)

    Caro-Bautista, Jorge; Martín-Santos, Francisco Javier; Morales-Asencio, Jose Miguel

    2014-06-01

    To determine the psychometric properties and theoretical grounding of instruments that evaluate self-care behaviour or barriers in people with type 2 diabetes. There are many instruments designed to evaluate self-care behaviour or barriers in this population, but knowledge about their psychometric validation processes is lacking. Systematic review. We conducted a search for psychometric or validation studies published between January 1990-December 2012. We carried out searches in Pubmed, CINAHL, PsycINFO, ProQuolid, BibliPRO and Google SCHOLAR to identify instruments that evaluated self-care behaviours or barriers to diabetes self-care. We conducted a systematic review with the following inclusion criteria: Psychometric or clinimetric validation studies that included patients with type 2 diabetes (exclusively or partially) and which analysed self-care behaviour or barriers to self-care and proxies like self-efficacy or empowerment, from a multidimensional approach. Language: Spanish or English. Two authors independently assessed the quality of the studies and extracted data using Terwee's proposed criteria: psychometrics properties, dimensionality, theoretical ground and population used for validation through each included instrument. Sixteen instruments achieved the inclusion criteria for the review. We detected important methodological flaws in many of the selected instruments. Only the Self-management Profile for Type 2 Diabetes and Problem Areas in Diabetes Scale met half of Terwee's quality criteria. There are no instruments for identifying self-care behaviours or barriers elaborated with a strong validation process. Further research should be carried out to provide patients, clinicians and researchers with valid and reliable instruments that are methodologically solid and theoretically grounded. © 2013 John Wiley & Sons Ltd.

  6. Ground-based Nuclear Detonation Detection (GNDD) Technology Roadmap

    Energy Technology Data Exchange (ETDEWEB)

    Casey, Leslie A.

    2014-01-13

    This GNDD Technology Roadmap is intended to provide guidance to potential researchers and help management define research priorities to achieve technology advancements for ground-based nuclear explosion monitoring science being pursued by the Ground-based Nuclear Detonation Detection (GNDD) Team within the Office of Nuclear Detonation Detection in the National Nuclear Security Administration (NNSA) of the U.S. Department of Energy (DOE). Four science-based elements were selected to encompass the entire scope of nuclear monitoring research and development (R&D) necessary to facilitate breakthrough scientific results, as well as deliver impactful products. Promising future R&D is delineated including dual use associated with the Comprehensive Nuclear-Test-Ban Treaty (CTBT). Important research themes as well as associated metrics are identified along with a progression of accomplishments, represented by a selected bibliography, that are precursors to major improvements to nuclear explosion monitoring.

  7. Understanding the Longitudinal Variability of Equatorial Electrodynamics using integrated Ground- and Space-based Observations

    Science.gov (United States)

    Yizengaw, E.; Moldwin, M.; Zesta, E.

    2015-12-01

    The currently funded African Meridian B-Field Education and Research (AMBER) magnetometer array comprises more than thirteen magnetometers stationed globally in the vicinity of geomagnetic equator. One of the main objectives of AMBER network is to understand the longitudinal variability of equatorial electrodynamics as function of local time, magnetic activity, and season. While providing complete meridian observation in the region and filling the largest land-based gap in global magnetometer coverage, the AMBER array addresses two fundamental areas of space physics: first, the processes governing electrodynamics of the equatorial ionosphere as a function of latitude (or L-shell), local time, longitude, magnetic activity, and season, and second, ULF pulsation strength at low/mid-latitude regions and its connection with equatorial electrojet and density fluctuation. The global AMBER network can also be used to augment observations from space-based instruments, such us the triplet SWARM mission and the upcoming ICON missions. Thus, in coordination with space-based and other ground-based observations, the AMBER magnetometer network provides a great opportunity to understand the electrodynamics that governs equatorial ionosphere motions. In this paper we present the longitudinal variability of the equatorial electrodynamics using the combination of instruments onboard SWARM and C/NOFS satellites and ground-based AMBER network. Both ground- and pace-based observations show stronger dayside and evening sector equatorial electrodynamics in the American and Asian sectors compared to the African sector. On the other hand, the African sector is home to stronger and year-round ionospheric bubbles/irregularities compared to the American and Asian sectors. This raises the question if the evening sector equatorial electrodynamics (vertical drift), which is believed to be the main cause for the enhancement of Rayleigh-Taylor (RT) instability growth rate, is stronger in the

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2014-02-01

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

  9. A comparative study of satellite and ground-based phenology.

    Science.gov (United States)

    Studer, S; Stöckli, R; Appenzeller, C; Vidale, P L

    2007-05-01

    Long time series of ground-based plant phenology, as well as more than two decades of satellite-derived phenological metrics, are currently available to assess the impacts of climate variability and trends on terrestrial vegetation. Traditional plant phenology provides very accurate information on individual plant species, but with limited spatial coverage. Satellite phenology allows monitoring of terrestrial vegetation on a global scale and provides an integrative view at the landscape level. Linking the strengths of both methodologies has high potential value for climate impact studies. We compared a multispecies index from ground-observed spring phases with two types (maximum slope and threshold approach) of satellite-derived start-of-season (SOS) metrics. We focus on Switzerland from 1982 to 2001 and show that temporal and spatial variability of the multispecies index correspond well with the satellite-derived metrics. All phenological metrics correlate with temperature anomalies as expected. The slope approach proved to deviate strongly from the temporal development of the ground observations as well as from the threshold-defined SOS satellite measure. The slope spring indicator is considered to indicate a different stage in vegetation development and is therefore less suited as a SOS parameter for comparative studies in relation to ground-observed phenology. Satellite-derived metrics are, however, very susceptible to snow cover, and it is suggested that this snow cover should be better accounted for by the use of newer satellite sensors.

  10. Ground-based Space Weather Monitoring with LOFAR

    Science.gov (United States)

    Wise, Michael; van Haarlem, Michiel; Lawrence, Gareth; Reid, Simon; Bos, Andre; Rawlings, Steve; Salvini, Stef; Mitchell, Cathryn; Soleimani, Manuch; Amado, Sergio; Teresa, Vital

    As one of the first of a new generation of radio instruments, the International LOFAR Telescope (ILT) will provide a number of unique and novel capabilities for the astronomical community. These include remote configuration and operation, dynamic real-time processing and system response, and the ability to provide multiple simultaneous streams of data to a community whose scientific interests run the gamut from lighting in the atmospheres of distant planets to the origins of the universe itself. The LOFAR (LOw Frequency ARray) system is optimized for a frequency range from 30-240 MHz and consists of multiple antenna fields spread across Europe. In the Netherlands, a total 36 LOFAR stations are nearing completion with an initial 8 international stations currently being deployed in Germany, France, Sweden, and the UK. Digital beam-forming techniques make the LOFAR system agile and allow for rapid repointing of the telescope as well as the potential for multiple simultaneous observations. With its dense core array and long interferometric baselines, LOFAR has the potential to achieve unparalleled sensitivity and spatial resolution in the low frequency radio regime. LOFAR will also be one of the first radio observatories to feature automated processing pipelines to deliver fully calibrated science products to its user community. As we discuss in this presentation, the same capabilities that make LOFAR a powerful tool for radio astronomy also provide an excellent platform upon which to build a ground-based monitoring system for space weather events. For example, the ability to monitor Solar activity in near real-time is one of the key scientific capabilities being developed for LOFAR. With only a fraction of its total observing capacity, LOFAR will be able to provide continuous monitoring of the Solar spectrum over the entire 10-240 MHz band down to microsecond timescales. Autonomous routines will scan these incoming spectral data for evidence of Solar flares and be

  11. Advanced ESPI-based medical instruments for otolaryngology

    Science.gov (United States)

    Castracane, James; Conerty, M.; Cacace, Anthony T.; Gardner, Glendon M.; Miller, Mitchell B.; Parnes, Steven M.

    1993-05-01

    Optical fibers have long been used for visual inspection inside the human body for medical diagnoses and treatment. By making use of sophisticated optical interferometric and ultra- small imaging techniques, combined with automated image processing, it is possible to extract significantly increased information for more accurate medical diagnoses. With support from NIH under the SBIR program, we have been developing a range of such instruments. One of these supported by the NIDCD is capable of providing detailed spatial information on the vibratory response of the tympanic membrane (TM). This instrument involves the examination of the TM by means of high speed electronic speckle pattern interferometry (ESPI). This provides a real time view of the vibration patterns of the TM for clinical diagnosis. This Interferometric Otoscope consists of mode conserving fiber optics, miniature diode lasers and high speed solid state detector arrays. We present the current status of the research including holography and ESPI of TM models and excised temporal bone preparations. A second instrument, also developed with support from NIDCD, is for application to the larynx. This system is also ESPI based but will incorporate features for direct vocal cord (VC) examination. By careful examination of the vibratory response of the VC during phonation, the characteristics of the mucosal wave may be examined. Adynamic regions of the cords can signal the start of lesions or cysts. Results of surgery can be evaluated in a quantitative manner. The design of a clinical prototype and preliminary electro-optic experiments on excised larynges and VC models will be presented.

  12. MEMS Test System Based on Virtual Instrument Technology

    Institute of Scientific and Technical Information of China (English)

    HU Xiaodong; LI Dachao; GUO Tong; HU Chunguang; HU Xiaotang

    2007-01-01

    On account of the multiformity of MEMS devices, it is necessary to integrate with some optical measurement techniques for meeting static and dynamic unit test requirements. In this paper, an automated MEMS test system is built of some commercially available components and instruments based on virtual instrument technology. The system is integrated with stroboscopic imaging, computer micro-vision, microscopic Mirau phase shifting interferometry, and laser Doppler vibrometer, and is used for the measurement of full-view in-plane and out-of-plane geometric parameters and periodical motions and single spot out-of-plane transient motion. The system configuration and measurement methods are analyzed, and some applications of the measurement of in-plane and out-of-plane dimensions and motions were described. The measurement accuracy of in-plane dimensions and out-of-plane dimensional is better than 0.2 μm and 5 nm respectively. The resolution of measuring in-plane and out-of-plane motions is better than 15 nm and 22 nm respectively.

  13. Understanding the Laminar Distribution of Tropospheric Ozone from Ground-Based, Airborne, Spaceborne, and Modeling Perspectives

    Science.gov (United States)

    Newchurch, Mike; Johnson, Matthew S.; Huang, Guanyu; Kuang, Shi; Wang, Lihua; Chance, Kelly; Liu, Xiong

    2016-01-01

    Laminar ozone structure is a ubiquitous feature of tropospheric-ozone distributions resulting from dynamic and chemical atmospheric processes. Understanding the characteristics of these ozone laminae and the mechanisms responsible for producing them is important to outline the transport pathways of trace gases and to quantify the impact of different sources on tropospheric background ozone. In this study, we present a new method to detect ozone laminae to understand their climatological characteristics of occurrence frequency in terms of thickness and altitude. We employ both ground-based and airborne ozone lidar measurements and other synergistic observations and modeling to investigate the sources and mechanisms such as biomass burning transport, stratospheric intrusion, lightning-generated NOx, and nocturnal low-level jets that are responsible for depleted or enhanced tropospheric ozone layers. Spaceborne (e.g., OMI (Ozone Monitoring Instrument), TROPOMI (Tropospheric Monitoring Instrument), TEMPO (Tropospheric Emissions: Monitoring of Pollution)) measurements of these laminae will observe greater horizontal extent and lower vertical resolution than balloon-borne or lidar measurements will quantify. Using integrated ground-based, airborne, and spaceborne observations in a modeling framework affords insight into how to gain knowledge of both the vertical and horizontal evolution of these ubiquitous ozone laminae.

  14. Ground-based complex for checking the optical system

    Science.gov (United States)

    Grebenyuk, V.; Boreiko, V.; Dmitrotsa, A.; Gorbunov, N.; Khrenov, B.; Klimov, P.; Lavrova, M.; Popescu, E. M.; Sabirov, B.; Tkachenko, A.; Tkachev, L.; Volvach, A.; Yashin, I.

    2016-09-01

    The purpose TUS space experiment is to study cosmic rays of ultrahigh energies produced by extensive air showers from space. The concentrator is located on satellite, made in the form of the Fresnel mirror towards the earth's atmosphere, the focus of which is a photodetector. The angle of view of the mirror is ±4.5° that for a given height of the orbit corresponds to the area 80 × 80 km2 on ground. The ground complex consisting of a number of stations, to check the optical system of the experiment is created, (their location and the amount will be determined after the launch of the satellite based on its actual orbit).

  15. Ground extraction from airborne laser data based on wavelet analysis

    Science.gov (United States)

    Xu, Liang; Yang, Yan; Jiang, Bowen; Li, Jia

    2007-11-01

    With the advantages of high resolution and accuracy, airborne laser scanning data are widely used in topographic mapping. In order to generate a DTM, measurements from object features such as buildings, vehicles and vegetation have to be classified and removed. However, the automatic extraction of bare earth from point clouds acquired by airborne laser scanning equipment remains a problem in LIDAR data filtering nowadays. In this paper, a filter algorithm based on wavelet analysis is proposed. Relying on the capability of detecting discontinuities of continuous wavelet transform and the feature of multi-resolution analysis, the object points can be removed, while ground data are preserved. In order to evaluate the performance of this approach, we applied it to the data set used in the ISPRS filter test in 2003. 15 samples have been tested by the proposed approach. Results showed that it filtered most of the objects like vegetation and buildings, and extracted a well defined ground model.

  16. Network operability of ground-based microwave radiometers: Calibration and standardization efforts

    Science.gov (United States)

    Pospichal, Bernhard; Löhnert, Ulrich; Küchler, Nils; Czekala, Harald

    2017-04-01

    Ground-based microwave radiometers (MWR) are already widely used by national weather services and research institutions all around the world. Most of the instruments operate continuously and are beginning to be implemented into data assimilation for atmospheric models. Especially their potential for continuously observing boundary-layer temperature profiles as well as integrated water vapor and cloud liquid water path makes them valuable for improving short-term weather forecasts. However until now, most MWR have been operated as stand-alone instruments. In order to benefit from a network of these instruments, standardization of calibration, operation and data format is necessary. In the frame of TOPROF (COST Action ES1303) several efforts have been undertaken, such as uncertainty and bias assessment, or calibration intercomparison campaigns. The goal was to establish protocols for providing quality controlled (QC) MWR data and their uncertainties. To this end, standardized calibration procedures for MWR have been developed and recommendations for radiometer users compiled. Based on the results of the TOPROF campaigns, a new, high-accuracy liquid-nitrogen calibration load has been introduced for MWR manufactured by Radiometer Physics GmbH (RPG). The new load improves the accuracy of the measurements considerably and will lead to even more reliable atmospheric observations. Next to the recommendations for set-up, calibration and operation of ground-based MWR within a future network, we will present homogenized methods to determine the accuracy of a running calibration as well as means for automatic data quality control. This sets the stage for the planned microwave calibration center at JOYCE (Jülich Observatory for Cloud Evolution), which will be shortly introduced.

  17. Laser transmitter for space-based sodium lidar instrument

    Science.gov (United States)

    Yu, Anthony W.; Krainak, Michael A.; Janches, Diego; Konoplev, Oleg

    2016-05-01

    We are currently developing a laser transmitter to remotely measure Sodium (Na) by adapting existing lidar technology with space flight heritage. The developed instrumentation will serve as the core for the planning of a Heliophysics mission targeted to study the composition and dynamics of Earth's mesosphere based on a spaceborne lidar that will measure the mesospheric Na layer. We present performance results from our laser transmitter development effort with emphasis on wavelength tuning and power scaling of a diode-pumped Q-switched self-Raman c-cut Nd:YVO4 laser with intra-cavity frequency doubling that could produce multi-watt 589 nm wavelength output. We will review technologies that provide strong leverage for the sodium lidar laser system with strong heritage from past and current space flight missions.

  18. PhotoSpec - Ground-based Remote Sensing of Solar-Induced Chlorophyll Fluorescence: First Results

    Science.gov (United States)

    Grossmann, K.; Magney, T. S.; Frankenberg, C.; Seibt, U.; Pivovaroff, A. L.; Hurlock, S. C.; Stutz, J.

    2016-12-01

    Solar-Induced Chlorophyll Fluorescence (SIF) emitted from vegetation can be used as a proxy for photosynthetic activity and is observable on a global scale from space. However, many issues on a leaf-to-canopy scale remain poorly understood, such as influences on the SIF signal from environmental conditions, water stress, or radiation. We have developed a novel ground-based spectrometer system for measuring SIF from natural ecosystems. The instrumental set-up, requirements, and measurement technique are based on decades of experience using Differential Optical Absorption Spectroscopy (DOAS), an established method to measure atmospheric trace gases. The instrument consists of three thermally stabilized commercial spectrometers that are linked to a 2D scanning telescope unit via optical fiber bundles, and also includes a commercial photosynthetic active radiation (PAR) sensor. The spectrometers cover a SIF retrieval wavelength range at high spectral resolution (670 - 780 nm, 0.1 nm FWHM), and also provide moderate resolution spectra (400 - 800 nm, 1.5 nm FWHM) to retrieve vegetation indices and the photochemical reflectance index (PRI). We report on results of the first continuous field measurements of this novel system at Stunt Ranch Santa Monica Mountains UC Reserve, where the PhotoSpec instrument was monitoring SIF of four native Californian shrubland species with different adaptations to seasonal summer drought. We report on the correlation with CO2 fluxes over both the growing season and the hot summer period in 2016. We also show detailed measurements of the diurnal cycle of the SIF signal of single broad leaves, as well as dark-light transitions, under controlled experimental conditions. In addition to demonstrating the instrumental set-up, retrieval algorithm, and instrument performance, our results illustrate that SIF measurements at the leaf to ecosystem scale are needed to understand and interpret the SIF signals retrieved at larger scales.

  19. Improved ground-based remote-sensing systems help monitor plant response to climate and other changes

    Science.gov (United States)

    Dye, Dennis G.; Bogle, Rian C.

    2016-05-26

    Scientists at the U.S. Geological Survey are improving and developing new ground-based remote-sensing instruments and techniques to study how Earth’s vegetation responds to changing climates. Do seasonal grasslands and forests “green up” early (or late) and grow more (or less) during unusually warm years? How do changes in temperature and precipitation affect these patterns? Innovations in ground-based remote-sensing instrumentation can help us understand, assess, and mitigate the effects of climate change on vegetation and related land resources.

  20. Performance study of ground-based infrared Bracewell interferometers - Application to the detection of exozodiacal dust disks with GENIE

    CERN Document Server

    Absil, O; Gondoin, P; Fabry, P; Wilhelm, R; Gitton, P; Puech, F

    2005-01-01

    Nulling interferometry, a powerful technique for high-resolution imaging of the close neighbourhood of bright astrophysical objets, is currently considered for future space missions such as Darwin or the Terrestrial Planet Finder Interferometer (TPF-I), both aiming at Earth-like planet detection and characterization. Ground-based nulling interferometers are being studied for both technology demonstration and scientific preparation of the Darwin/TPF-I missions through a systematic survey of circumstellar dust disks around nearby stars. In this paper, we investigate the influence of atmospheric turbulence on the performance of ground-based nulling instruments, and deduce the major design guidelines for such instruments. End-to-end numerical simulations allow us to estimate the performance of the main subsystems and thereby the actual sensitivity of the nuller to faint exozodiacal disks. Particular attention is also given to the important question of stellar leakage calibration. This study is illustrated in the ...

  1. Ground penetrating detection using miniaturized radar system based on solid state microwave sensor.

    Science.gov (United States)

    Yao, B M; Fu, L; Chen, X S; Lu, W; Guo, H; Gui, Y S; Hu, C-M

    2013-12-01

    We propose a solid-state-sensor-based miniaturized microwave radar technique, which allows a rapid microwave phase detection for continuous wave operation using a lock-in amplifier rather than using expensive and complicated instruments such as vector network analyzers. To demonstrate the capability of this sensor-based imaging technique, the miniaturized system has been used to detect embedded targets in sand by measuring the reflection for broadband microwaves. Using the reconstruction algorithm, the imaging of the embedded target with a diameter less than 5 cm buried in the sands with a depth of 5 cm or greater is clearly detected. Therefore, the sensor-based approach emerges as an innovative and cost-effective way for ground penetrating detection.

  2. An evaluation of IASI-NH3 with ground-based Fourier transform infrared spectroscopy measurements

    Science.gov (United States)

    Dammers, Enrico; Palm, Mathias; Van Damme, Martin; Vigouroux, Corinne; Smale, Dan; Conway, Stephanie; Toon, Geoffrey C.; Jones, Nicholas; Nussbaumer, Eric; Warneke, Thorsten; Petri, Christof; Clarisse, Lieven; Clerbaux, Cathy; Hermans, Christian; Lutsch, Erik; Strong, Kim; Hannigan, James W.; Nakajima, Hideaki; Morino, Isamu; Herrera, Beatriz; Stremme, Wolfgang; Grutter, Michel; Schaap, Martijn; Wichink Kruit, Roy J.; Notholt, Justus; Coheur, Pierre-F.; Erisman, Jan Willem

    2016-08-01

    Global distributions of atmospheric ammonia (NH3) measured with satellite instruments such as the Infrared Atmospheric Sounding Interferometer (IASI) contain valuable information on NH3 concentrations and variability in regions not yet covered by ground-based instruments. Due to their large spatial coverage and (bi-)daily overpasses, the satellite observations have the potential to increase our knowledge of the distribution of NH3 emissions and associated seasonal cycles. However the observations remain poorly validated, with only a handful of available studies often using only surface measurements without any vertical information. In this study, we present the first validation of the IASI-NH3 product using ground-based Fourier transform infrared spectroscopy (FTIR) observations. Using a recently developed consistent retrieval strategy, NH3 concentration profiles have been retrieved using observations from nine Network for the Detection of Atmospheric Composition Change (NDACC) stations around the world between 2008 and 2015. We demonstrate the importance of strict spatio-temporal collocation criteria for the comparison. Large differences in the regression results are observed for changing intervals of spatial criteria, mostly due to terrain characteristics and the short lifetime of NH3 in the atmosphere. The seasonal variations of both datasets are consistent for most sites. Correlations are found to be high at sites in areas with considerable NH3 levels, whereas correlations are lower at sites with low atmospheric NH3 levels close to the detection limit of the IASI instrument. A combination of the observations from all sites (Nobs = 547) give a mean relative difference of -32.4 ± (56.3) %, a correlation r of 0.8 with a slope of 0.73. These results give an improved estimate of the IASI-NH3 product performance compared to the previous upper-bound estimates (-50 to +100 %).

  3. Virtual Instrument Based on GPIB Interface Bus1

    Institute of Scientific and Technical Information of China (English)

    Xiao,Ying; Qi,Hanhong

    2004-01-01

    In this paper, we introduced the technique of GPIB businterface. Through the controlling of the GPIB interface board,the computer controlled the current source and the voltmeter, both of which have GPIB bus interface, and a virtual instrument testing system for I~V curve was composed. The virtual instrument front panel and the background graphical control program in Labview environment accomplish virtual instrument testing task along with the hardware system.

  4. Augmenting WFIRST Microlensing with a Ground-Based Telescope Network

    Science.gov (United States)

    Zhu, Wei; Gould, Andrew

    2016-06-01

    Augmenting the Wide Field Infrared Survey Telescope (WFIRST) microlensing campaigns with intensive observations from a ground-based network of wide-field survey telescopes would have several major advantages. First, it would enable full two-dimensional (2-D) vector microlens parallax measurements for a substantial fraction of low-mass lenses as well as planetary and binary events that show caustic crossing features. For a significant fraction of the free-floating planet (FFP) events and all caustic-crossing planetary/binary events, these 2-D parallax measurements directly lead to complete solutions (mass, distance, transverse velocity) of the lens object (or lens system). For even more events, the complementary ground-based observations will yield 1-D parallax measurements. Together with the 1-D parallaxes from WFIRST alone, they can probe the entire mass range M > M_Earth. For luminous lenses, such 1-D parallax measurements can be promoted to complete solutions (mass, distance, transverse velocity) by high-resolution imaging. This would provide crucial information not only about the hosts of planets and other lenses, but also enable a much more precise Galactic model. Other benefits of such a survey include improved understanding of binaries (particularly with low mass primaries), and sensitivity to distant ice-giant and gas-giant companions of WFIRST lenses that cannot be detected by WFIRST itself due to its restricted observing windows. Existing ground-based microlensing surveys can be employed if WFIRST is pointed at lower-extinction fields than is currently envisaged. This would come at some cost to the event rate. Therefore the benefits of improved characterization of lenses must be weighed against these costs.

  5. Diamond color measurement instrument based on image processing

    Science.gov (United States)

    Takahashi, H.; Mandal, S.; Toosi, M.; Zeng, J.; Wang, W.

    2016-09-01

    Gemological Institute of America (GIA) has developed a diamond color measurement instrument that can provide accurate and reproducible color measurement results. The instrument uses uniform illumination by a daylight-approximating light source; observations from a high-resolution color-camera with nearly zero-distortion bi-telecentric lens, and image processing to calculate color parameters of diamonds. Experiments show the instrument can provide reproducible color measurement results and also identify subtle color differences in diamonds with high sensitivity. The experimental setup of the prototype instrument and the image processing method for calculating diamond color parameters are presented in this report.

  6. Robotic, MEMS-based Multi Utility Sample Preparation Instrument for ISS Biological Workstation Project

    Data.gov (United States)

    National Aeronautics and Space Administration — This project will develop a multi-functional, automated sample preparation instrument for biological wet-lab workstations on the ISS. The instrument is based on a...

  7. A LEKID-based CMB instrument design for large-scale observations in Greenland

    Science.gov (United States)

    Araujo, D. C.; Ade, P. A. R.; Bond, J. R.; Bradford, K. J.; Chapman, D.; Che, G.; Day, P. K.; Didier, J.; Doyle, S.; Eriksen, H. K.; Flanigan, D.; Groppi, C. E.; Hillbrand, Seth N.; Johnson, B. R.; Jones, G.; Limon, Michele; Miller, A. D.; Mauskopf, P.; McCarrick, H.; Mroczkowski, T.; Reichborn-Kjennerud, B.; Smiley, B.; Sobrin, Joshua; Wehus, I. K.; Zmuidzinas, J.

    2014-08-01

    We present the results of a feasibility study, which examined deployment of a ground-based millimeter-wave polarimeter, tailored for observing the cosmic microwave background (CMB), to Isi Station in Greenland. The instrument for this study is based on lumped-element kinetic inductance detectors (LEKIDs) and an F/2.4 catoptric, crossed-Dragone telescope with a 500 mm aperture. The telescope is mounted inside the receiver and cooled to Linearly polarized signals from the sky are modulated with a metal-mesh half-wave plate that is rotated at the aperture stop of the telescope with a hollow-shaft motor based on a superconducting magnetic bearing. The modular detector array design includes at least 2300 LEKIDs, and it can be configured for spectral bands centered on 150 GHz or greater. Our study considered configurations for observing in spectral bands centered on 150, 210 and 267 GHz. The entire polarimeter is mounted on a commercial precision rotary air bearing, which allows fast azimuth scan speeds with negligible vibration and mechanical wear over time. A slip ring provides power to the instrument, enabling circular scans (360 degrees of continuous rotation). This mount, when combined with sky rotation and the latitude of the observation site, produces a hypotrochoid scan pattern, which yields excellent cross-linking and enables 34% of the sky to be observed using a range of constant elevation scans. This scan pattern and sky coverage combined with the beam size (15 arcmin at 150 GHz) makes the instrument sensitive to 5 < ` < 1000 in the angular power spectra.

  8. The STACEE-32 Ground Based Gamma-ray Detector

    CERN Document Server

    Hanna, D S; Boone, L M; Chantell, M C; Conner, Z; Covault, C E; Dragovan, M; Fortin, P; Gregorich, D T; Hinton, J A; Mukherjee, R; Ong, R A; Oser, S; Ragan, K; Scalzo, R A; Schütte, D R; Theoret, C G; Tümer, T O; Williams, D A; Zweerink, J A

    2002-01-01

    We describe the design and performance of the Solar Tower Atmospheric Cherenkov Effect Experiment detector in its initial configuration (STACEE-32). STACEE is a new ground-based gamma ray detector using the atmospheric Cherenkov technique. In STACEE, the heliostats of a solar energy research array are used to collect and focus the Cherenkov photons produced in gamma-ray induced air showers. The large Cherenkov photon collection area of STACEE results in a gamma-ray energy threshold below that of previous detectors.

  9. The STACEE Ground-Based Gamma-Ray Detector

    CERN Document Server

    Gingrich, D M; Bramel, D; Carson, J; Covault, C E; Fortin, P; Hanna, D S; Hinton, J A; Jarvis, A; Kildea, J; Lindner, T; Müller, C; Mukherjee, R; Ong, R A; Ragan, K; Scalzo, R A; Theoret, C G; Williams, D A; Zweerink, J A

    2005-01-01

    We describe the design and performance of the Solar Tower Atmospheric Cherenkov Effect Experiment (STACEE) in its complete configuration. STACEE uses the heliostats of a solar energy research facility to collect and focus the Cherenkov photons produced in gamma-ray induced air showers. The light is concentrated onto an array of photomultiplier tubes located near the top of a tower. The large Cherenkov photon collection area of STACEE results in a gamma-ray energy threshold below that of previous ground-based detectors. STACEE is being used to observe pulsars, supernova remnants, active galactic nuclei, and gamma-ray bursts.

  10. Research on target accuracy for ground-based lidar

    Science.gov (United States)

    Zhu, Ling; Shi, Ruoming

    2009-05-01

    In ground based Lidar system, the targets are used in the process of registration, georeferencing for point cloud, and also can be used as check points. Generally, the accuracy of capturing the flat target center is influenced by scanning range and scanning angle. In this research, the experiments are designed to extract accuracy index of the target center with 0-90°scan angles and 100-195 meter scan ranges using a Leica HDS3000 laser scanner. The data of the experiments are listed in detail and the related results are analyzed.

  11. Ground-Based Global Positioning System (GPS) Meteorology Integrated Precipitable Water Vapor (IPW)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Ground-Based Global Positioning System (GPS) Meteorology Integrated Precipitable Water Vapor (IPW) data set measures atmospheric water vapor using ground-based...

  12. Applications of FBG-based sensors to ground stability monitoring

    Institute of Scientific and Technical Information of China (English)

    An-Bin Huang; Chien-Chih Wang; Jui-Ting Lee; Yen-Te Ho

    2016-01-01

    Over the past few decades, many optical fiber sensing techniques have been developed. Among these available sensing methods, optical fiber Bragg grating (FBG) is probably the most popular one. With its unique capabilities, FBG-based geotechnical sensors can be used as a sensor array for distributive (profile) measurements, deployed under water (submersible), for localized high resolution and/or dif-ferential measurements. The authors have developed a series of FBG-based transducers that include inclination, linear displacement and gauge/differential pore pressure sensors. Techniques that involve the field deployment of FBG inclination, extension and pore-pressure sensor arrays for automated slope stability and ground subsidence monitoring have been developed. The paper provides a background of FBG and the design concepts behind the FBG-based field monitoring sensors. Cases of field monitoring using the FBG sensor arrays are presented, and their practical implications are discussed.

  13. Data acquisition instrument for EEG based on embedded system

    Science.gov (United States)

    Toresano, La Ode Husein Z.; Wijaya, Sastra Kusuma; Prawito, Sudarmaji, Arief; Syakura, Abdan; Badri, Cholid

    2017-02-01

    An electroencephalogram (EEG) is a device for measuring and recording the electrical activity of brain. The EEG data of signal can be used as a source of analysis for human brain function. The purpose of this study was to design a portable multichannel EEG based on embedded system and ADS1299. The ADS1299 is an analog front-end to be used as an Analog to Digital Converter (ADC) to convert analog signal of electrical activity of brain, a filter of electrical signal to reduce the noise on low-frequency band and a data communication to the microcontroller. The system has been tested to capture brain signal within a range of 1-20 Hz using the NETECH EEG simulator 330. The developed system was relatively high accuracy of more than 82.5%. The EEG Instrument has been successfully implemented to acquire the brain signal activity using a PC (Personal Computer) connection for displaying the recorded data. The final result of data acquisition has been processed using OpenBCI GUI (Graphical User Interface) based through real-time process for 8-channel signal acquisition, brain-mapping and power spectral decomposition signal using the standard FFT (Fast Fourier Transform) algorithm.

  14. Microcomputer based instrument for measuring a novel pulmonary function test

    Science.gov (United States)

    Craine, Brian L.; Craine, Eric R.

    1996-08-01

    The design of a prototype instrument for measuring the end-tidal concentration of carbon monoxide during human respiration is presented. The instrument automatically samples the final sixty cubic centimeters of exhaled breath, from successive breathing cycles, by coordinating a pump and the breathing cycle with a set of vacuum and pressure sensors. The concentration of carbon monoxide is measured using a nondispersive infrared spectrophotometer. The amount of carbon monoxide present is measured relative to the source air concentration eliminating the need for calibrating the instrument. The testing protocol and measurements can be controlled by a microcomputer connected to the instrument through a standard RS-232 serial interface. When at equilibrium, the end-tidal concentration of CO can be measured in a simple and reproducible fashion. This simplified technology allows for the construction of a small, portable, easy to use instrument that will allow the application of this new pulmonary function test at the point of contact with patients.

  15. Petascale Computing for Ground-Based Solar Physics with the DKIST Data Center

    Science.gov (United States)

    Berukoff, Steven J.; Hays, Tony; Reardon, Kevin P.; Spiess, DJ; Watson, Fraser; Wiant, Scott

    2016-05-01

    When construction is complete in 2019, the Daniel K. Inouye Solar Telescope will be the most-capable large aperture, high-resolution, multi-instrument solar physics facility in the world. The telescope is designed as a four-meter off-axis Gregorian, with a rotating Coude laboratory designed to simultaneously house and support five first-light imaging and spectropolarimetric instruments. At current design, the facility and its instruments will generate data volumes of 3 PB per year, and produce 107-109 metadata elements.The DKIST Data Center is being designed to store, curate, and process this flood of information, while providing association of science data and metadata to its acquisition and processing provenance. The Data Center will produce quality-controlled calibrated data sets, and make them available freely and openly through modern search interfaces and APIs. Documented software and algorithms will also be made available through community repositories like Github for further collaboration and improvement.We discuss the current design and approach of the DKIST Data Center, describing the development cycle, early technology analysis and prototyping, and the roadmap ahead. We discuss our iterative development approach, the underappreciated challenges of calibrating ground-based solar data, the crucial integration of the Data Center within the larger Operations lifecycle, and how software and hardware support, intelligently deployed, will enable high-caliber solar physics research and community growth for the DKIST's 40-year lifespan.

  16. Statistical Studies of Ground-Based Optical Lightning Signatures

    Science.gov (United States)

    Hunt, C. R.; Nemzek, R. J.; Suszcynsky, D. M.

    2005-12-01

    Most extensive optical studies of lightning have been conducted from orbit, and the statistics of events collected from earth are relatively poorly documented. The time signatures of optical power measured in the presence of clouds are inevitably affected by scattering,which can distort the signatures by extending and delaying the amplitude profile in time. We have deployed two all-sky photodiode detectors, one in New Mexico and one in Oklahoma, which are gathering data alongside electric field change monitors as part of the LANL EDOTX Great Plains Array. Preliminary results show that the photodiode is sensitive to approximately 50% or more of RF events detected at ranges of up to 30 km, and still has some sensitivity at ranges in excess of 60 km (distances determined by the EDOTX field-change array). The shapes of events within this range were assessed, with focus on rise time, width, peak power, and their correlation to corresponding electric field signatures, and these are being compared with published on-orbit and ground-based data. Initial findings suggest a mean characteristic width (ratio of total detected optical energy to peak power) of 291 +/- 12 microseconds and a mean delay between the RF signal peak and optical peak of 121 +/- 17 microseconds. These values fall between prior ground-based measurements of direct return stroke emissions, and scattering-dominated on-orbit measurements. This work will promote better understanding of the correspondence between radio and optical measurements of lightning.

  17. Real-time Gaussian Markov random-field-based ground tracking for ground penetrating radar data

    Science.gov (United States)

    Bradbury, Kyle; Torrione, Peter A.; Collins, Leslie

    2009-05-01

    Current ground penetrating radar algorithms for landmine detection require accurate estimates of the location of the air/ground interface to maintain high levels of performance. However, the presence of surface clutter, natural soil roughness, and antenna motion lead to uncertainty in these estimates. Previous work on improving estimates of the location of the air/ground interface have focused on one-dimensional filtering techniques to localize the air/ground interface. In this work, we propose an algorithm for interface localization using a 2- D Gaussian Markov random field (GMRF). The GMRF provides a statistical model of the surface structure, which enables the application of statistical optimization techniques. In this work, the ground location is inferred using iterated conditional modes (ICM) optimization which maximizes the conditional pseudo-likelihood of the GMRF at a point, conditioned on its neighbors. To illustrate the efficacy of the proposed interface localization approach, pre-screener performance with and without the proposed ground localization algorithm is compared. We show that accurate localization of the air/ground interface provides the potential for future performance improvements.

  18. Assessment of NASA Airborne Laser Altimetry Data Using Ground-Based GPS Data near Summit Station, Greenland

    Science.gov (United States)

    Brunt, Kelly M.; Hawley, Robert L.; Lutz, Eric R.; Studinger, Michael; Sonntag, John G.; Hofton, Michelle A.; Andrews, Lauren C.; Neumann, Thomas A.

    2017-01-01

    A series of NASA airborne lidars have been used in support of satellite laser altimetry missions. These airbornelaser altimeters have been deployed for satellite instrument development, for spaceborne data validation, and to bridge the data gap between satellite missions. We used data from ground-based Global Positioning System (GPS) surveys of an 11 km long track near Summit Station, Greenland, to assess the surface elevation bias and measurement precision of three airborne laser altimeters including the Airborne Topographic Mapper (ATM), the Land, Vegetation, and Ice Sensor (LVIS), and the Multiple Altimeter Beam Experimental Lidar (MABEL). Ground-based GPS data from the monthly ground-based traverses, which commenced in 2006, allowed for the assessment of nine airborne lidar surveys associated with ATM and LVIS between 2007 and 2016. Surface elevation biases for these altimeters over the flat, ice-sheet interior are less than 0.12 m, while assessments of measurement precision are 0.09 m or better. Ground-based GPS positions determined both with and without differential post-processing techniques provided internally consistent solutions. Results from the analyses of ground-based and airborne data provide validation strategy guidance for the Ice, Cloud, and land Elevation Satellite 2 (ICESat-2) elevation and elevation-change data products.

  19. PCI express hotplug implementation for ATCA based instrumentation

    Energy Technology Data Exchange (ETDEWEB)

    Carvalho, Paulo F.; Santos, Bruno; Correia, Miguel; Combo, Álvaro M.; Rodrigues, António P. [Instituto Plasmas e Fusão Nuclear, Instituto Superior Técnico, Universidade Técnica de Lisboa, 1049-001 Lisboa (Portugal); Pereira, Rita C., E-mail: pricardofc@ipfn.ist.utl.pt [Instituto Plasmas e Fusão Nuclear, Instituto Superior Técnico, Universidade Técnica de Lisboa, 1049-001 Lisboa (Portugal); Fernandes, Ana; Cruz, Nuno; Sousa, Jorge; Carvalho, Bernardo B.; Batista, António J.N. [Instituto Plasmas e Fusão Nuclear, Instituto Superior Técnico, Universidade Técnica de Lisboa, 1049-001 Lisboa (Portugal); Correia, Carlos M.B.A. [Centro de Instrumentação, Departamento de Física, Universidade de Coimbra, 3004-516 Coimbra (Portugal); Gonçalves, Bruno [Instituto Plasmas e Fusão Nuclear, Instituto Superior Técnico, Universidade Técnica de Lisboa, 1049-001 Lisboa (Portugal)

    2015-10-15

    Highlights: • Hotplug capabilities are designed as an expected or graceful methodology in which the user is not permitted to install or remove a PCIe endpoint device without first notifying the system software. • Hotswap capabilities allow endpoints or PCIe switches with endpoints to be inserted or removed from a PCIe system gracefully or unexpectedly without special consideration. • ATCA, advanced telecommunication computer architecture is a new specification with high availability and high reliability key features which improves data acquisition systems. • Data acquisition systems are used almost everywhere and a demand in the nuclear fusion research field. • Nuclear fusion is a future alternative for power and energy resources generation for world humanity consumption. - Abstract: This paper describes a Peripheral Component Interconnect Express (PCIe) hotplug and hotswap capability implementation for advanced telecommunication computer architecture (ATCA) based instrumentation. PCIe hotplug provides card insertion and removal capability from a running PCIe-based platform without causing system damages and not requiring an entire system shutdown. PCIe hotswap allows endpoints or PCIe switches with endpoint cards to be inserted or removed from a PCIe system gracefully or unexpectedly without special considerations. Control and data acquisition (C&DAQ) cards need to be replaced from a system for fault-condition repair, hardware malfunction, firmware updates or upgrades and hardware reconfiguration. ATCA specification key features such as high reliability and high availability for C&DAQ systems strongly benefits from these capabilities taking advantage from Redhat Enterprise Linux, installed operating system, and corresponding kernel with built-in mechanisms and embedded software modules for hotplug and hotswap support. PCIe hotplug and hotswap implemented solutions in the ATCA-based prototype provides described capabilities to the C&DAQ and PCIe switch

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

    Science.gov (United States)

    Rödelsperger, Sabine; Meta, Adriano

    2014-10-01

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

  1. System-level view of geospace dynamics: Challenges for high-latitude ground-based observations

    Science.gov (United States)

    Donovan, E.

    2014-12-01

    Increasingly, research programs including GEM, CEDAR, GEMSIS, GO Canada, and others are focusing on how geospace works as a system. Coupling sits at the heart of system level dynamics. In all cases, coupling is accomplished via fundamental processes such as reconnection and plasma waves, and can be between regions, energy ranges, species, scales, and energy reservoirs. Three views of geospace are required to attack system level questions. First, we must observe the fundamental processes that accomplish the coupling. This "observatory view" requires in situ measurements by satellite-borne instruments or remote sensing from powerful well-instrumented ground-based observatories organized around, for example, Incoherent Scatter Radars. Second, we need to see how this coupling is controlled and what it accomplishes. This demands quantitative observations of the system elements that are being coupled. This "multi-scale view" is accomplished by networks of ground-based instruments, and by global imaging from space. Third, if we take geospace as a whole, the system is too complicated, so at the top level we need time series of simple quantities such as indices that capture important aspects of the system level dynamics. This requires a "key parameter view" that is typically provided through indices such as AE and DsT. With the launch of MMS, and ongoing missions such as THEMIS, Cluster, Swarm, RBSP, and ePOP, we are entering a-once-in-a-lifetime epoch with a remarkable fleet of satellites probing processes at key regions throughout geospace, so the observatory view is secure. With a few exceptions, our key parameter view provides what we need. The multi-scale view, however, is compromised by space/time scales that are important but under-sampled, combined extent of coverage and resolution that falls short of what we need, and inadequate conjugate observations. In this talk, I present an overview of what we need for taking system level research to its next level, and how

  2. Identification of rainy periods from ground based microwave radiometry

    Directory of Open Access Journals (Sweden)

    Ada Vittoria Bosisio

    2012-03-01

    Full Text Available In this paper the authors present the results of a study aiming at detecting rainy data in measurements collected by a dual band ground-based radiometer. The proposed criterion is based on the ratio of the brightness temperatures observed in the 20-30 GHz band without need of any ancillary information. A major result obtained from the probability density of the ratio computed over one month of data is the identification of threshold values between clear sky, cloudy sky and rainy sky, respectively. A linear fit performed by using radiometric data and concurrent rain gauge measurements shows a correlation coefficient equal to 0.56 between the temperature ratio and the observed precipitation.

  3. Unique cell culture systems for ground based research

    Science.gov (United States)

    Lewis, Marian L.

    1990-01-01

    The horizontally rotating fluid-filled, membrane oxygenated bioreactors developed at NASA Johnson for spacecraft applications provide a powerful tool for ground-based research. Three-dimensional aggregates formed by cells cultured on microcarrier beads are useful for study of cell-cell interactions and tissue development. By comparing electron micrographs of plant seedlings germinated during Shuttle flight 61-C and in an earth-based rotating bioreactor it is shown that some effects of microgravity are mimicked. Bioreactors used in the UAH Bioreactor Laboratory will make it possible to determine some of the effects of altered gravity at the cellular level. Bioreactors can be valuable for performing critical, preliminary-to-spaceflight experiments as well as medical investigations such as in vitro tumor cell growth and chemotherapeutic drug response; the enrichment of stem cells from bone marrow; and the effect of altered gravity on bone and muscle cell growth and function and immune response depression.

  4. Spatial-angular modeling of ground-based biaxial lidar

    Science.gov (United States)

    Agishev, Ravil R.

    1997-10-01

    Results of spatial-angular LIDAR modeling based on an efficiency criterion introduced are represented. Their analysis shows that a low spatial-angular efficiency of traditional VIS and NIR systems is a main cause of a low S/BR ratio at the photodetector input. It determines the considerable measurements errors and the following low accuracy of atmospheric optical parameters retrieval. As we have shown, the most effective protection against intensive sky background radiation for ground-based biaxial LIDAR's consist in forming of their angular field according to spatial-angular efficiency criterion G. Some effective approaches to high G-parameter value achievement to achieve the receiving system optimization are discussed.

  5. An Electron Beam Profile Instrument Based on FBGs

    Directory of Open Access Journals (Sweden)

    Dan Sporea

    2014-08-01

    Full Text Available Along with the dose rate and the total irradiation dose measurements, the knowledge of the beam localization and the beam profile/energy distribution in the beam are parameters of interest for charged particle accelerator installations when they are used in scientific investigations, industrial applications or medical treatments. The transverse profile of the beam, its position, its centroid location, and its focus or flatness depend on the instrument operating conditions or on the beam exit setup. Proof-of-concept of a new type of charged particle beam diagnostics based on fiber Bragg gratings (FBGs was demonstrated. Its operating principle relies on the measurement of the peak wavelength changes for an array of FBG sensors as function of the temperature following the exposure to an electron beam. Periodically, the sensor irradiation is stopped and the FBG are force cooled to a reference temperature with which the temperature influencing each sensor during beam exposure is compared. Commercially available FBGs, and FBGs written in radiation resistant optical fibers, were tested under electron beam irradiation in order to study their possible use in this application.

  6. Design of a TFT-LCD Based Digital Automobile Instrument

    Directory of Open Access Journals (Sweden)

    Yunsong Xu

    2014-01-01

    instrument and gives an introduction to the sampling circuits and interfaces related to these signals. Following this is the functional categorizing of the circuit modules, such as video buffer circuit, CAN bus interface circuit, and TFT-LCD drive circuit. Additionally, the external EEPROM stores information of the vehicle for history data query, and the external FLASH enables the display of high quality figures. On the whole, the accomplished automobile instrument meets the requirements of automobile instrument markets with its characters of low cost, favorable compatibility, friendly interfaces, and easy upgrading.

  7. High-precision ground-based photometry of exoplanets

    Directory of Open Access Journals (Sweden)

    de Mooij Ernst J.W.

    2013-04-01

    Full Text Available High-precision photometry of transiting exoplanet systems has contributed significantly to our understanding of the properties of their atmospheres. The best targets are the bright exoplanet systems, for which the high number of photons allow very high signal-to-noise ratios. Most of the current instruments are not optimised for these high-precision measurements, either they have a large read-out overhead to reduce the readnoise and/or their field-of-view is limited, preventing simultaneous observations of both the target and a reference star. Recently we have proposed a new wide-field imager for the Observatoir de Mont-Megantic optimised for these bright systems (PI: Jayawardhana. The instruments has a dual beam design and a field-of-view of 17' by 17'. The cameras have a read-out time of 2 seconds, significantly reducing read-out overheads. Over the past years we have obtained significant experience with how to reach the high precision required for the characterisation of exoplanet atmospheres. Based on our experience we provide the following advice: Get the best calibrations possible. In the case of bad weather, characterise the instrument (e.g. non-linearity, dome flats, bias level, this is vital for better understanding of the science data. Observe the target for as long as possible, the out-of-transit baseline is as important as the transit/eclipse itself. A short baseline can lead to improperly corrected systematic and mis-estimation of the red-noise. Keep everything (e.g. position on detector, exposure time as stable as possible. Take care that the defocus is not too strong. For a large defocus, the contribution of the total flux from the sky-background in the aperture could well exceed that of the target, resulting in very strict requirements on the precision at which the background is measured.

  8. DDCC-Based Quadrature Oscillator with Grounded Capacitors and Resistors

    Directory of Open Access Journals (Sweden)

    Montree Kumngern

    2009-01-01

    Full Text Available A new voltage-mode quadrature oscillator using two differential difference current conveyors (DDCCs, two grounded capacitors, and three grounded resistors is presented. The proposed oscillator provides the following advantages: the oscillation condition and oscillation frequency are orthogonally controlled; the oscillation frequency is controlled through a single grounded resistor; the use of only grounded capacitors and resistors makes the proposed circuit ideal for IC implementation; low passive and active sensitivities. Simulation results verifying the theoretical analysis are also included.

  9. Using Model-Based Reasoning for Autonomous Instrument Operation - Lessons Learned From IMAGE/LENA

    Science.gov (United States)

    Johnson, Michael A.; Rilee, Michael L.; Truszkowski, Walt; Bailin, Sidney C.

    2001-01-01

    Model-based reasoning has been applied as an autonomous control strategy on the Low Energy Neutral Atom (LENA) instrument currently flying on board the Imager for Magnetosphere-to-Aurora Global Exploration (IMAGE) spacecraft. Explicit models of instrument subsystem responses have been constructed and are used to dynamically adapt the instrument to the spacecraft's environment. These functions are cast as part of a Virtual Principal Investigator (VPI) that autonomously monitors and controls the instrument. In the VPI's current implementation, LENA's command uplink volume has been decreased significantly from its previous volume; typically, no uplinks are required for operations. This work demonstrates that a model-based approach can be used to enhance science instrument effectiveness. The components of LENA are common in space science instrumentation, and lessons learned by modeling this system may be applied to other instruments. Future work involves the extension of these methods to cover more aspects of LENA operation and the generalization to other space science instrumentation.

  10. Merging Old and New: An Instrumentation-Based Introductory Analytical Laboratory

    Science.gov (United States)

    Jensen, Mark B.

    2015-01-01

    An instrumentation-based laboratory curriculum combining traditional unknown analyses with student-designed projects has been developed for an introductory analytical chemistry course. In the first half of the course, students develop laboratory skills and instrumental proficiency by rotating through six different instruments performing…

  11. Coordinated studies of the geospace environment using Cluster, satellite and ground-based data: an interim review

    Directory of Open Access Journals (Sweden)

    O. Amm

    2005-09-01

    Full Text Available A little more than four years after its launch, the first magnetospheric, multi-satellite mission Cluster has already tremendously contributed to our understanding about the coupled solar wind - magnetosphere - ionosphere system. This is mostly due to its ability, for the first time, to provide instantaneous spatial views of structures in the system, to separate temporal and spatial variations, and to derive velocities and directions of moving structures. Ground-based data have an important complementary impact on Cluster-related research, as they provide a larger-scale context to put the spacecraft data in, allow to virtually enlarge the spacecrafts' field of view, and make it possible to study in detail the coupling between the magnetosphere and the ionosphere in a spatially extended domain. With this paper we present an interim review of cooperative research done with Cluster and ground-based instruments, including the support of other space-based data. We first give a short overview of the instrumentation used, and present some specific data analysis and modeling techniques that have been devised for the combined analysis of Cluster and ground-based data. Then we review highlighted results of the research using Cluster and ground-based data, ordered into dayside and nightside processes. Such highlights include, for example, the identification of the spatio-temporal signatures of the different modes of reconnection on the dayside, and the detailed analysis of the electrodynamic magnetosphere-ionosphere coupling of bursty bulk flows in the tail plasma sheet on the nightside. The aim of this paper is to provide a "sourcebook" for the Cluster and ground-based community that summarises the work that has been done in this field of research, and to identify open questions and possible directions for future studies.

    Keywords. Ionosphere (Auroral ionosphere – Magnetospheric physics (Magnetosphere-ionosphere interactions; General or

  12. Instrumentation for PSD-based neutron diffractometers at Dhruva reactor

    Indian Academy of Sciences (India)

    S S Pande; S P Borkar; S Prafulla; V D Srivastava; A Behare; P K Mukhopadhyay; M D Ghodgaonkar; S K Kataria

    2004-08-01

    Linear position sensitive detectors (PSDs) are widely used to configure neutron diffractometers and other instruments. Necessary front-end electronics and a data acquisition system [1] is developed to cater to such instruments built around the Dhruva research reactor in BARC. These include three diffractometers with multiple PSDs and four with single PSD. The front-end electronics consists of high voltage units, preamplifiers [2], shaping amplifiers, ratio ADCs (RDC) [3]. The data acquisition system consists of an interface card and software. Commercially available hardware like temperature controller or stepper motor controller connected over GPIB or RS232 are also integrated in the data acquisition system. The data acquisition is automated so that it can continue unattended for control parameter like temperature, thus enabling optimum utilization of available beam time. The instrumentation is scalable and can be easily configured for various instrumental requirements. The front-end electronics and the data acquisition system are described here.

  13. Modelling systematics of ground-based transit photometry I. Implications on transit timing variations

    CERN Document Server

    von Essen, C; Mallonn, M; Tingley, B; Marcussen, M

    2016-01-01

    The transit timing variation technique (TTV) has been widely used to detect and characterize multiple planetary systems. Due to the observational biases imposed mainly by the photometric conditions and instrumentation and the high signal-to-noise required to produce primary transit observations, ground-based data acquired using small telescopes limit the technique to the follow-up of hot Jupiters. However, space-based missions such as Kepler and CoRoT have already revealed that hot Jupiters are mainly found in single systems. Thus, it is natural to question ourselves if we are properly using the observing time at hand carrying out such follow-ups, or if the use of medium-to-low quality transit light curves, combined with current standard techniques of data analysis, could be playing a main role against exoplanetary search via TTVs. The purpose of this work is to investigate to what extent ground-based observations treated with current modelling techniques are reliable to detect and characterize additional pla...

  14. Ground-based and spacecraft observations of lightning activity on Saturn

    Science.gov (United States)

    Zakharenko, V.; Mylostna, C.; Konovalenko, A.; Zarka, P.; Fischer, G.; Grießmeier, J.-M.; Litvinenko, G.; Rucker, H.; Sidorchuk, M.; Ryabov, B.; Vavriv, D.; Ryabov, V.; Cecconi, B.; Coffre, A.; Denis, L.; Fabrice, C.; Pallier, L.; Schneider, J.; Kozhyn, R.; Vinogradov, V.; Mukha, D.; Weber, R.; Shevchenko, V.; Nikolaenko, V.

    2012-02-01

    In late 2007, Saturn electrostatic discharges (SED) were simultaneously observed at the radio telescope UTR-2 and with the Cassini spacecraft. Observations at UTR-2 were performed with a multichannel receiver in the frequency range 12-33 MHz, and those performed on Cassini-with a swept frequency receiver that is part of the RPWS (Radio and Plasma Wave Science) instrument in the frequency band 1.8-16 MHz. We got a very good coincidence between data of UTR-2 and Cassini. It is shown for the first time that ground-based radio astronomy lets us detect Saturn's lightning with a high degree of reliability despite terrestrial interferences. This is the necessary basis for further detailed study of the temporal and spectral characteristics of the SEDs with ground based radio telescopes. Based on six observation sessions, several parameters of SEDs were determined, in particularly a correlation of 0.77±0.15 between the average intensity of storms and the e-folding time.

  15. Instrument classification in polyphonic music based on timbre analysis

    Science.gov (United States)

    Zhang, Tong

    2001-07-01

    While most previous work on musical instrument recognition is focused on the classification of single notes in monophonic music, a scheme is proposed in this paper for the distinction of instruments in continuous music pieces which may contain one or more kinds of instruments. Highlights of the system include music segmentation into notes, harmonic partial estimation in polyphonic sound, note feature calculation and normalization, note classification using a set of neural networks, and music piece categorization with fuzzy logic principles. Example outputs of the system are `the music piece is 100% guitar (with 90% likelihood)' and `the music piece is 60% violin and 40% piano, thus a violin/piano duet'. The system has been tested with twelve kinds of musical instruments, and very promising experimental results have been obtained. An accuracy of about 80% is achieved, and the number can be raised to 90% if misindexings within the same instrument family are tolerated (e.g. cello, viola and violin). A demonstration system for musical instrument classification and music timbre retrieval is also presented.

  16. Comparison of OMI UV observations with ground-based measurements at high northern latitudes

    Directory of Open Access Journals (Sweden)

    G. Bernhard

    2015-03-01

    Full Text Available The Dutch-Finnish Ozone Monitoring Instrument (OMI on board NASA's Aura spacecraft provides estimates of erythemal (sunburning ultraviolet (UV dose rates and erythemal daily doses. These data were compared with ground-based measurements at 13 stations located throughout the Arctic and Scandinavia from 60 to 83° N. The study corroborates results from earlier work, but is based on a longer time series (eight vs. two years and considers additional data products, such as the erythemal dose rate at the time of the satellite overpass. Furthermore, systematic errors in satellite UV data resulting from inaccuracies in the surface albedo climatology used in the OMI UV algorithm are systematically assessed. At times when the surface albedo is correctly known, OMI data typically exceed ground-based measurements by 0–11%. When the OMI albedo climatology exceeds the actual albedo, OMI data may be biased high by as much as 55%. In turn, when the OMI albedo climatology is too low, OMI data can be biased low by up to 59%. Such large negative biases may occur when reflections from snow and ice, which increase downwelling UV irradiance, are misinterpreted as reflections from clouds, which decrease the UV flux at the surface. Results suggest that a better OMI albedo climatology would greatly improve the accuracy of OMI UV data products even if year-to-year differences of the actual albedo cannot be accounted for. A pathway for improving the OMI albedo climatology is discussed. Results also demonstrate that ground-based measurements from the center of Greenland, where high, homogenous surface albedo is observed year round, are ideally suited to detect systematic problems or temporal drifts in estimates of surface UV irradiance from space.

  17. Ground-based microwave measuring of middle atmosphere ozone and temperature profiles during sudden stratospheric warming

    Science.gov (United States)

    Feigin, A. M.; Shvetsov, A. A.; Krasilnikov, A. A.; Kulikov, M. Y.; Karashtin, D. A.; Mukhin, D.; Bolshakov, O. S.; Fedoseev, L. I.; Ryskin, V. G.; Belikovich, M. V.; Kukin, L. M.

    2012-12-01

    satellite data. However, in opposite to satellite measurements, ground-based instrument registers properly daily variations of ozone concentration above 50 km.

  18. Solar energy assessment in the Alpine area: satellite data and ground instruments integration for studying the radiative forcing of aerosols.

    Science.gov (United States)

    Castelli, M.; Petitta, M.; Emili, E.

    2012-04-01

    The primary objective of this work is to purpose an approach for estimating the effect of aerosols on surface incoming shortwave radiation (SIS) in the Alpine region, which is based on the integration of different instruments: we develop a GIS model, whose output is corrected by monthly atmospheric coefficients, and then we progressively add details by daily updated atmospheric information. The assessment of solar energy availability at the earth's surface over a specific geographic area is crucial for planning photovoltaic panels installation. When modeling SIS with GIS instruments or retrieving it from satellites measurements, we have to account for terrain shadowing and atmospheric extinction, both of which are difficult to describe in the Alpine area, because of the topographic complexity and the local atmospheric circulation influence on the atmospheric composition. While advanced methods were developed to carefully describe the effect of topography, the atmospheric attenuation was considered so far only through monthly turbidity values, and the question remains whether it be possible to develop a time-effective routine to model the atmospheric effect on SIS at daily scale. As a first step we produced a WebGIS for the town of Bressanone, Italy, showing a classification of the roofs of the buildings according to the yearly amount of global irradiance. Furthermore we provide the annual electricity production based on the efficiency of the most common PV technologies. At this stage clear sky irradiance was computed with a GIS based model, and afterwards monthly correction coefficients were applied to add real sky conditions to the merely geometrical computations, which were obtained from 20 years of measurement collected by the pyranometer in the closest meteorological station. As a second step we investigate the influence of aerosol optical properties on SIS by running the radiative transfer model libRadtran by using as input the aerosol model defined for the

  19. Ground-based optical observation system for LEO objects

    Science.gov (United States)

    Yanagisawa, T.; Kurosaki, H.; Oda, H.; Tagawa, M.

    2015-08-01

    We propose a ground-based optical observation system for monitoring LEO objects, which uses numerous optical sensors to cover a vast region of the sky. Its potential in terms of detection and orbital determination were examined. About 30 cm LEO objects at 1000 km altitude are detectable using an 18 cm telescope, a CCD camera and the analysis software developed. Simulations and a test observation showed that two longitudinally separate observation sites with arrays of optical sensors can identify the same objects from numerous data sets and determine their orbits precisely. The proposed system may complement or replace the current radar observation system for monitoring LEO objects, like space-situation awareness, in the near future.

  20. Optical vortex coronagraphs on ground-based telescopes

    CERN Document Server

    Jenkins, Charles

    2007-01-01

    The optical vortex coronagraph is potentially a remarkably effective device, at least for an ideal unobstructed telescope. Most ground-based telescopes however suffer from central obscuration and also have to operate through the aberrations of the turbulent atmosphere. This note analyzes the performance of the optical vortex in these circumstances and compares to some other designs, showing that it performs similarly in this situation. There is a large class of coronagraphs of this general type, and choosing between them in particular applications depends on details of performance at small off-axis distances and uniformity of response in the focal plane. Issues of manufacturability to the necessary tolerances are also likely to be important.

  1. Advanced instrumentation for acousto-ultrasonic based structural health monitoring

    Science.gov (United States)

    Smithard, Joel; Galea, Steve; van der Velden, Stephen; Powlesland, Ian; Jung, George; Rajic, Nik

    2016-04-01

    Structural health monitoring (SHM) systems using structurally-integrated sensors potentially allow the ability to inspect for damage in aircraft structures on-demand and could provide a basis for the development of condition-based maintenance approaches for airframes. These systems potentially offer both substantial cost savings and performance improvements over conventional nondestructive inspection (NDI). Acousto-ultrasonics (AU), using structurallyintegrated piezoelectric transducers, offers a promising basis for broad-field damage detection in aircraft structures. For these systems to be successfully applied in the field the hardware for AU excitation and interrogation needs to be easy to use, compact, portable, light and, electrically and mechanically robust. Highly flexible and inexpensive instrumentation for basic background laboratory investigations is also required to allow researchers to tackle the numerous scientific and engineering issues associated with AU based SHM. The Australian Defence Science and Technology Group (DST Group) has developed the Acousto Ultrasonic Structural health monitoring Array Module (AUSAM+), a compact device for AU excitation and interrogation. The module, which has the footprint of a typical current generation smart phone, provides autonomous control of four send and receive piezoelectric elements, which can operate in pitch-catch or pulse-echo modes and can undertake electro-mechanical impedance measurements for transducer and structural diagnostics. Modules are designed to operate synchronously with other units, via an optical link, to accommodate larger transducer arrays. The module also caters for fibre optic sensing of acoustic waves with four intensity-based optical inputs. Temperature and electrical resistance strain gauge inputs as well as external triggering functionality are also provided. The development of a Matlab hardware object allows users to easily access the full hardware functionality of the device and

  2. Concurrent aerial and ground-based optical turbulence measurements along a long elevated path

    Science.gov (United States)

    Nowlin, Scott R.; Hahn, Ila L.; Hugo, Ronald J.; Bishop, Kenneth P.

    1999-08-01

    We report concurrent ground-based scintillator/airborne constant-current anemometer (CCA) measurements made along a 51.4 km-long slant path between Salinas and North Oscura peaks, NM. Simultaneous path-averaged refractive index structure parameter (Cn2) measurements from the CCA and the scintillometer show good agreement, with deviations apparently due to localized effects of underlying topography and metrology. Statistics from both data sets are presented in the form of histograms and cumulative distribution functions. CCA Cn2 point measurements are compared to underlying surface topography. We discuss possible effects of instruments anomalies, analysis methods, and atmospheric velocity fluctuation levels. We present conclusions and made recommendations for future similar experimental efforts.

  3. Impact of particles on the Planck HFI detectors: Ground-based measurements and physical interpretation

    CERN Document Server

    Catalano, A; Atik, Y; Benoit, A; Bréele, E; Bock, J J; Camus, P; Chabot, M; Charra, M; Crill, B P; Coron, N; Coulais, A; Désert, F -X; Fauvet, L; Giraud-Héraud, Y; Guillaudin, O; Holmes, W; Jones, W C; Lamarre, J -M; Macías-Pérez, J; Martinez, M; Miniussi, A; Monfardini, A; Pajot, F; Patanchon, G; Pelissier, A; Piat, M; Puget, J -L; Renault, C; Rosset, C; Santos, D; Sauvé, A; Spencer, L D; Sudiwala, R

    2014-01-01

    The Planck High Frequency Instrument (HFI) surveyed the sky continuously from August 2009 to January 2012. Its noise and sensitivity performance were excellent, but the rate of cosmic ray impacts on the HFI detectors was unexpectedly high. Furthermore, collisions of cosmic rays with the focal plane produced transient signals in the data (glitches) with a wide range of characteristics. A study of cosmic ray impacts on the HFI detector modules has been undertaken to categorize and characterize the glitches, to correct the HFI time-ordered data, and understand the residual effects on Planck maps and data products. This paper presents an evaluation of the physical origins of glitches observed by the HFI detectors. In order to better understand the glitches observed by HFI in flight, several ground-based experiments were conducted with flight-spare HFI bolometer modules. The experiments were conducted between 2010 and 2013 with HFI test bolometers in different configurations using varying particles and impact ener...

  4. Future Ground-Based Solar System Research: a Prospective Workshop Summary

    Science.gov (United States)

    Boehnhardt, H.; Käufl, H. U.

    2009-09-01

    The article tries to provide a perspective summary of the planetary science to be performed with future extremely large telescopes (ELTs) as an outcome of the workshop on ‘Future Ground-based Solar System Research: Synergies between Space Probes and Space Telescopes’ held on 8-12 September 2008 in Portoferraio on Isola d’ Elba, Italy. It addresses science cases on solar system objects that might challenge the capabilities of ELTs and that provide a major step forward in the knowledge and understanding of planetary system objects per se and all populations. We also compile high-level requirements for such telescopes and their instrumentation that should enable successful ELT usage for research on objects in the Solar System, the ‘disturbing foreground to real astronomy’.

  5. Ground characterization and roof mapping:Online sensor signal-based change detection

    Institute of Scientific and Technical Information of China (English)

    Bahrampour Soheil; Rostami Jamal; Ray Asok; Naeimipour Ali; Collins Craig

    2015-01-01

    Measurement while drilling systems are becoming an important part of excavation operations for rock characterization and ground support design that require reliable information on rock strength and loca-tion&frequency of joints or voids. This paper focuses on improving rock characterization algorithms for instrumented roof-bolter systems. For this purpose, an improved void detection algorithm is proposed, where the underlying theory is built upon the concept of mean change detection based on the feed pressure signals. In addition, the application of acoustic sensing for void detection is examined and it is shown that the variance of the filtered acoustic signal is correlated to the strength of the material being drilled. The proposed algorithm has been validated on the data collected from full-scale drilling tests in various concrete and rock samples at the J. H. Fletcher facility.

  6. Relative Throughput of the Near-IR Science Instruments for the James Webb Space Telescope as Measured During Ground Testing the Integrated Science Instrument Module

    Science.gov (United States)

    Malumuth, Eliot; Birkmann, Stephan; Kelly, Douglas M.; Kimble, Randy A.; Lindler, Don; Martel, Andre; Ohl, Raymond G.; Rieke, Marcia J.; Rowlands, Neil; Te Plate, Maurice

    2016-01-01

    Data were obtained for the purpose of measuring the relative throughput of the Near-IR Science Instruments (SIs) of the James Webb Space Telescope (JWST) as part of the second and third cryogenic-vacuum tests (CV2CV3) of the Integrated Science Instrument Module (ISIM) conducted at the Goddard Space Flight Center (GSFC) in 2014 and 20152016, at the beginning and end of the environmental test program, respectively. This Poster focuses on data obtained as part of the Initial Optical Baseline and as part of the Final Performance test -- two epochs that roughly bracket the CV3 test. The purpose of the test is to trend relative throughput to monitor for any potential changes from gross problems such as contamination or degradation of an optical element. Point source data were taken at a variety of wavelengths for NIRCam Module A and Module B, NIRSpec, NIRISS, Guider 1 and Guider 2 using the Laser Diode (LD) 1.06 micron, LD 1.55 micron, 2.1 micron LED and 3.5 micron LED, as well as for NIRCam Mod A and B and NIRISS using a tungsten source and the F277W, and F480M filters. Spectra were taken using the G140M, G235M, and G395M gratings for NIRSpec, the GRISMR grism for NIRCam Mod A and B and the GR150C grism for NIRISS. The results of these measurements are compared to what would be expected given the efficiency of each of the optical elements in each SI. Although these data were taken as a check against gross problems, they can also be used to provide the first relative throughput estimate for each SI through the various filters source wavelengths measured in their flight-like configurations.

  7. A portable detection instrument based on DSP for beef marbling

    Science.gov (United States)

    Zhou, Tong; Peng, Yankun

    2014-05-01

    Beef marbling is one of the most important indices to assess beef quality. Beef marbling is graded by the measurement of the fat distribution density in the rib-eye region. However quality grades of beef in most of the beef slaughtering houses and businesses depend on trainees using their visual senses or comparing the beef slice to the Chinese standard sample cards. Manual grading demands not only great labor but it also lacks objectivity and accuracy. Aiming at the necessity of beef slaughtering houses and businesses, a beef marbling detection instrument was designed. The instrument employs Charge-coupled Device (CCD) imaging techniques, digital image processing, Digital Signal Processor (DSP) control and processing techniques and Liquid Crystal Display (LCD) screen display techniques. The TMS320DM642 digital signal processor of Texas Instruments (TI) is the core that combines high-speed data processing capabilities and real-time processing features. All processes such as image acquisition, data transmission, image processing algorithms and display were implemented on this instrument for a quick, efficient, and non-invasive detection of beef marbling. Structure of the system, working principle, hardware and software are introduced in detail. The device is compact and easy to transport. The instrument can determine the grade of beef marbling reliably and correctly.

  8. Automated Planning of Science Products Based on Nadir Overflights and Alerts for Onboard and Ground Processing

    Science.gov (United States)

    Chien, Steve A.; McLaren, David A.; Rabideau, Gregg R.; Mandl, Daniel; Hengemihle, Jerry

    2013-01-01

    A set of automated planning algorithms is the current operations baseline approach for the Intelligent Payload Module (IPM) of the proposed Hyper spectral Infrared Imager (HyspIRI) mission. For this operations concept, there are only local (e.g. non-depletable) operations constraints, such as real-time downlink and onboard memory, and the forward sweeping algorithm is optimal for determining which science products should be generated onboard and on ground based on geographical overflights, science priorities, alerts, requests, and onboard and ground processing constraints. This automated planning approach was developed for the HyspIRI IPM concept. The HyspIRI IPM is proposed to use an X-band Direct Broadcast (DB) capability that would enable data to be delivered to ground stations virtually as it is acquired. However, the HyspIRI VSWIR and TIR instruments will produce approximately 1 Gbps data, while the DB capability is 15 Mbps for a approx. =60X oversubscription. In order to address this mismatch, this innovation determines which data to downlink based on both the type of surface the spacecraft is overflying, and the onboard processing of data to detect events. For example, when the spacecraft is overflying Polar Regions, it might downlink a snow/ice product. Additionally, the onboard software will search for thermal signatures indicative of a volcanic event or wild fire and downlink summary information (extent, spectra) when detected, thereby reducing data volume. The planning system described above automatically generated the IPM mission plan based on requested products, the overflight regions, and available resources.

  9. Estimation of Antarctic ozone loss from Ground-based total column measurements

    Directory of Open Access Journals (Sweden)

    J. Kuttippurath

    2010-03-01

    Full Text Available The passive ozone method is used to estimate ozone loss from ground-based measurements in the Antarctic. A sensitivity study shows that the O3 loss can be estimated within an accuracy of ~4%. The method is then applied to the observations from Amundsen-Scott/South Pole, Arrival Heights, Belgrano, Concordia, Dumont d'Urville, Faraday, Halley, Marambio, Neumayer, Rothera, Syowa and Zhongshan for the diagnosis of ozone loss in the Antarctic. On average, the five-day running mean of the vortex averaged ozone column loss deduced from the ground-based stations shows about 53% in 2009, 59% in 2008, 55% in 2007, 56% in 2006 and 61% in 2005. The observed O3 loss and loss rates are in very good agreement with the satellite observations (Ozone Monitoring Instrument and Sciamachy and are well reproduced by the model (Reprobus and SLIMCAT calculations.

    The historical ground-based total ozone measurements show that the depletion started in the late 1970s, reached a maximum in the early 1990s, stabilising afterwards at this level until present, with the exception of 2002, the year of an early vortex break-up. There is no indication of significant recovery yet.

    At southern mid-latitudes, a total ozone reduction of 40–50% is observed at the newly installed station Rio Gallegos and 25–35% at Kerguelen in October–November of 2008–2009 and 2005–2009 (except 2008 respectively, and of 10–20% at Macquarie Island in July–August of 2006–2009. This illustrates the significance of measurements at the edges of Antarctica.

  10. Ground-Based Network and Supersite Observations to Complement and Enrich EOS Research

    Science.gov (United States)

    Tsay, Si-Chee; Holben, Brent N.; Welton, Ellsworth J.

    2011-01-01

    Since 1997 NASA has been successfully launching a series of satellites - the Earth Observing System (EOS) - to intensively study, and gain a better understanding of, the Earth as an integrated system. Space-borne remote sensing observations, however, are often plagued by contamination of surface signatures. Thus, ground-based in-situ and remote-sensing measurements, where signals come directly from atmospheric constituents, the sun, and/or the Earth-atmosphere interactions, provide additional information content for comparisons that confirm quantitatively the usefulness of the integrated surface, aircraft, and satellite datasets. Through numerous participations, particularly but not limited to the EOS remote-sensing/retrieval and validation projects over the years, NASA/GSFC has developed and continuously refined ground-based networks and mobile observatories that proved to be vital in providing high temporal measurements, which complement and enrich the satellite observations. These are: the AERO NET (AErosol RObotic NETwork) a federation of ground-based globally distributed network of spectral sun-sky photometers; the MPLNET (Micro-Pulse Lidar NETwork, a similarly organized network of micro-pulse lidar systems measuring aerosol and cloud vertical structure continuously; and the SMART-COMMIT (Surface-sensing Measurements for Atmospheric Radiative Transfer - Chemical, Optical & Microphysical Measurements of In-situ Troposphere, mobile observatories, a suite of spectral radiometers and in-situ probes acquiring supersite measurements. Most MPLNET sites are collocated with those of AERONET, and both networks always support the deployment of SMART-COMMIT worldwide. These data products follow the data structure of EOS conventions: Level-0, instrument archived raw data; Level-1 (or 1.5), real-time data with no (or limited) quality assurance; Level-2, not real high temporal and spectral resolutions. In this talk, we will present NASA/GSFC groundbased facilities, serving

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

    Science.gov (United States)

    Tsay, Si-Chee

    2008-01-01

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

  12. Mesospheric minor species determinations from rocket and ground-based i.r. measurements

    Science.gov (United States)

    Ulwick, J. C.; Baker, K. D.; Baker, D. J.; Steed, A. J.; Pendleton, W. R.; Grossmann, K.; Brückelmann, H. G.

    As part of the MAP/WINE campaign the infrared hydroxyl airglow layer was investigated at Kiruna, Sweden, by simultaneous measurements with rocket probes of OH ≠ and O2( a1Δg) infrared emissions and concentrations of odd oxygen species (O and O 3). Coordinated measurements of OH ≠ and O2( a1Δg) zenith radiance and emission spectra and their time histories were made from the ground. The rocket-borne Λ = 1.55 μm radiometer ( ΔΛ ≊ 0.23 μm) provided volume emission rates for OH for both rocket ascent and descent, showing a peak near 87 km with a maximum of nearly 10 6 photons sec -1 cm -3. The atomic oxygen distribution showed a concentration of about 10 11 cm -3 between 88 and 100 km, dropping off sharply below 85 km. The ground-based radiometer at Λ = 1.56 μm, which had a similar filter bandpass to the rocket-borne instrument, yielded an equivalent of 130 kR for the total OH Δv = 2 sequence, which is consistent with the zenith-corrected rocket-based sequence radiance value of ≌ 110 kR. The rotational temperature of the OH night airglow obtained from the rotational structure of the OH M (3,1) band observed by the ground-based interferometer was about 195K at the time of the rocket measurement. Atomic oxygen concentrations were calculated from the OH profile and show agreement with the directly measured values. Atomic hydrogen concentrations of a few times 10 7 cm -3 near 85 km were inferred from the data set.

  13. Ground-based observation of emission lines from the corona of a red-dwarf star.

    Science.gov (United States)

    Schmitt, J H; Wichmann, R

    2001-08-02

    All 'solar-like' stars are surrounded by coronae, which contain magnetically confined plasma at temperatures above 106 K. (Until now, only the Sun's corona could be observed in the optical-as a shimmering envelope during a total solar eclipse.) As the underlying stellar 'surfaces'-the photospheres-are much cooler, some non-radiative process must be responsible for heating the coronae. The heating mechanism is generally thought to be magnetic in origin, but is not yet understood even for the case of the Sun. Ultraviolet emission lines first led to the discovery of the enormous temperature of the Sun's corona, but thermal emission from the coronae of other stars has hitherto been detectable only from space, at X-ray wavelengths. Here we report the detection of emission from highly ionized iron (Fe XIII at 3,388.1 A) in the corona of the red-dwarf star CN Leonis, using a ground-based telescope. The X-ray flux inferred from our data is consistent with previously measured X-ray fluxes, and the non-thermal line width of 18.4 km s-1 indicates great similarities between solar and stellar coronal heating mechanisms. The accessibility and spectral resolution (45,000) of the ground-based instrument are much better than those of X-ray satellites, so a new window to the study of stellar coronae has been opened.

  14. De-mystifying earned value management for ground based astronomy projects, large and small

    Science.gov (United States)

    Norton, Timothy; Brennan, Patricia; Mueller, Mark

    2014-08-01

    The scale and complexity of today's ground based astronomy projects have justifiably required Principal Investigator's and their project teams to adopt more disciplined management processes and tools in order to achieve timely and accurate quantification of the progress and relative health of their projects. Earned Value Management (EVM) is one such tool. Developed decades ago and used extensively in the defense and construction industries, and now a requirement of NASA projects greater than $20M; EVM has gained a foothold in ground-based astronomy projects. The intent of this paper is to de-mystify EVM by discussing the fundamentals of project management, explaining how EVM fits with existing principles, and describing key concepts every project can use to implement their own EVM system. This paper also discusses pitfalls to avoid during implementation and obstacles to its success. The authors report on their organization's most recent experience implementing EVM for the GMT-Consortium Large Earth Finder (G-CLEF) project. G-CLEF is a fiber-fed, optical echelle spectrograph that has been selected as a first light instrument for the Giant Magellan Telescope (GMT), planned for construction at the Las Campanas Observatory in Chile's Atacama Desert region.

  15. Safeguards instrumentation: a computer-based catalog. Second edition

    Energy Technology Data Exchange (ETDEWEB)

    Auerbach, C.

    1985-04-01

    This catalog contains entries on new developments and on items listed in BNL 51450, which have either been carried over unchanged or been updated. More than 70 entries were deleted because of either obsolescence, insufficient interest in terms of safeguards, or lack of documentable development activities in recent years. Some old listings as well as new material was consolidated into more generic entries. As in the earlier document, the emphasis is on devices and instruments that are either in field use at this time or under active development. A few items such as NDA reference materials, instrument vans and certain shipping containers are included because they are important adjuncts to optimum utilization of safeguards instrumentation. This catalog does not include devices for physical protection. As was the case with its predecessor, most of the material in this catalog originated in the US and Canada; a few contributions came from member states of the European Community.

  16. Cooperation in environmental protection. The economics of green trade, market-based instruments and community involvement

    Energy Technology Data Exchange (ETDEWEB)

    Roettgers, Dirk

    2013-12-18

    The Millennium Development Goals (United Nations, 2000) and, by extension, such efforts as the Convention on Biological Diversity and the Kyoto Protocol (Kyoto Protocol, 1997), present mankind with a challenge that can only be overcome through cooperation. Cooperative policies are necessary from the highest level, i.e. international policies and treaties, to regional and national agreements, down to the local level, where policies are actually enacted. To close some gaps in the understanding of applicable policy instruments, this dissertation looks at a few key topics of environmental protection with implications for market-based instruments. The five different research areas are (1) EU bioenergy trade, (2) Clean Development Mechanism (CDM), (3) comparison of the effectiveness of product certification, ecosystem certification and offset mechanisms in wetland ecosystems, (4) international market-based instruments for African protected areas and (5) local stakeholder decision making in rural ecosystems of developing countries. Bioenergy consumption, production and trade have been increasing worldwide in the recent decade, mostly due to demand from EU countries and the USA. Taking the example of the EU, it is questionable if these trade flows are caused mainly by EU trade rules or targeted bioenergy policies. A sector-specific analysis taking industry patterns into consideration is necessary to evaluate the impact of these two policy areas on trade flows. A common way to analyze trade flows is the gravity model, which is employed here. This dissertation finds out why that is by using a gravity model to analyze flows of Certified Emission Reductions (CERs) between host and financier countries. The special roles of foreign direct investments (FDI), official development aid (ODA) and trade are scrutinized closely in this context. Findings show that FDI, ODA and trade have a positive influence on project attraction, even when holding determinants of these factors constant

  17. Validation of CALIPSO space-borne-derived attenuated backscatter coefficient profiles using a ground-based lidar in Athens, Greece

    Directory of Open Access Journals (Sweden)

    R. E. Mamouri

    2009-09-01

    Full Text Available We present initial aerosol validation results of the space-borne lidar CALIOP -onboard the CALIPSO satellite- Level 1 attenuated backscatter coefficient profiles, using coincident observations performed with a ground-based lidar in Athens, Greece (37.9° N, 23.6° E. A multi-wavelength ground-based backscatter/Raman lidar system is operating since 2000 at the National Technical University of Athens (NTUA in the framework of the European Aerosol Research LIdar NETwork (EARLINET, the first lidar network for tropospheric aerosol studies on a continental scale. Since July 2006, a total of 40 coincidental aerosol ground-based lidar measurements were performed over Athens during CALIPSO overpasses. The ground-based measurements were performed each time CALIPSO overpasses the station location within a maximum distance of 100 km. The duration of the ground–based lidar measurements was approximately two hours, centred on the satellite overpass time. From the analysis of the ground-based/satellite correlative lidar measurements, a mean bias of the order of 22% for daytime measurements and of 8% for nighttime measurements with respect to the CALIPSO profiles was found for altitudes between 3 and 10 km. The mean bias becomes much larger for altitudes lower that 3 km (of the order of 60% which is attributed to the increase of aerosol horizontal inhomogeneity within the Planetary Boundary Layer, resulting to the observation of possibly different air masses by the two instruments. In cases of aerosol layers underlying Cirrus clouds, comparison results for aerosol tropospheric profiles become worse. This is attributed to the significant multiple scattering effects in Cirrus clouds experienced by CALIPSO which result in an attenuation which is less than that measured by the ground-based lidar.

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

    Science.gov (United States)

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

    1993-01-01

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

  19. A LEKID-based CMB instrument design for large-scale observations in Greenland

    CERN Document Server

    Araujo, D C; Bond, J R; Bradford, K J; Chapman, D; Che, G; Day, P K; Didier, J; Doyle, S; Eriksen, H K; Flanigan, D; Groppi, C E; Hillbrand, S N; Johnson, B R; Jones, G; Limon, M; Miller, A D; Mauskopf, P; McCarrick, H; Mroczkowski, T; Reichborn-Kjennerud, B; Smiley, B; Sobrin, J; Wehus, I K; Zmuidzinas, J

    2014-01-01

    We present the results of a feasibility study, which examined deployment of a ground-based millimeter-wave polarimeter, tailored for observing the cosmic microwave background (CMB), to Isi Station in Greenland. The instrument for this study is based on lumped-element kinetic inductance detectors (LEKIDs) and an F/2.4 catoptric, crossed-Dragone telescope with a 500 mm aperture. The telescope is mounted inside the receiver and cooled to $<\\,4$ K by a closed-cycle $^4$He refrigerator to reduce background loading on the detectors. Linearly polarized signals from the sky are modulated with a metal-mesh half-wave plate that is rotated at the aperture stop of the telescope with a hollow-shaft motor based on a superconducting magnetic bearing. The modular detector array design includes at least 2300 LEKIDs, and it can be configured for spectral bands centered on 150~GHz or greater. Our study considered configurations for observing in spectral bands centered on 150, 210 and 267~GHz. The entire polarimeter is mounte...

  20. Comparison of the characteristic energy of precipitating electrons derived from ground-based and DMSP satellite data

    Directory of Open Access Journals (Sweden)

    M. Ashrafi

    2005-01-01

    Full Text Available Energy maps are important for ionosphere-magnetosphere coupling studies, because quantitative determination of field-aligned currents requires knowledge of the conductances and their spatial gradients. By combining imaging riometer absorption and all-sky auroral optical data it is possible to produce high temporal and spatial resolution maps of the Maxwellian characteristic energy of precipitating electrons within a 240240 common field of view. These data have been calibrated by inverting EISCAT electron density profiles into equivalent energy spectra. In this paper energy maps produced by ground-based instruments (optical and riometer are compared with DMSP satellite data during geomagnetic conjunctions. For the period 1995-2002, twelve satellite passes over the ground-based instruments' field of view for the cloud-free conditions have been considered. Four of the satellite conjunctions occurred during moderate geomagnetic, steady-state conditions and without any ion precipitation. In these cases with Maxwellian satellite spectra, there is 71% agreement between the characteristic energies derived from the satellite and the ground-based energy map method.

  1. Regaining the FORS: making optical ground-based transmission spectroscopy of exoplanets with VLT+FORS2 possible again

    CERN Document Server

    Boffin, Henri M J; Blanchard, Guillaume; Gonzalez, Oscar; Moehler, Sabine; Gibson, Neale; Ancker, Mario van den; Smoker, Jonathan; Anderson, Joseph; Hummel, Christian; Dobrzycka, Danuta; Smette, Alain; Rupprecht, Gero

    2016-01-01

    Transmission spectroscopy facilitates the detection of molecules and/or clouds in the atmospheres of exoplanets. Such studies rely heavily on space-based or large ground-based observatories, as one needs to perform time- resolved, high signal-to-noise spectroscopy. The FORS2 instrument at ESO's Very Large Telescope is the obvious choice for performing such studies, and was indeed pioneering the field in 2010. After that, however, it was shown to suffer from systematic errors caused by the Longitudinal Atmospheric Dispersion Corrector (LADC). This was successfully addressed, leading to a renewed interest for this instrument as shown by the number of proposals submitted to perform transmission spectroscopy of exoplanets. We present here the context, the problem and how we solved it, as well as the recent results obtained. We finish by providing tips for an optimum strategy to do transmission spectroscopy with FORS2, in the hope that FORS2 may become the instrument of choice for ground-based transmission spectro...

  2. Independet Component Analyses of Ground-based Exoplanetary Transits

    Science.gov (United States)

    Silva Martins-Filho, Walter; Griffith, Caitlin Ann; Pearson, Kyle; Waldmann, Ingo; Biddle, Lauren; Zellem, Robert Thomas; Alvarez-Candal, Alvaro

    2016-10-01

    Most observations of exoplanetary atmospheres are conducted when a "Hot Jupiter" exoplanet transits in front of its host star. These Jovian-sized planets have small orbital periods, on the order of days, and therefore a short transit time, making them more ameanable to observations. Measurements of Hot Jupiter transits must achieve a 10-4 level of accuracy in the flux to determine the spectral modulations of the exoplanetary atmosphere. In order to accomplish this level of precision, we need to extract systematic errors, and, for ground-based measurements, the effects of Earth's atmosphere, from the signal due to the exoplanet, which is several orders of magnitudes smaller. Currently, the effects of the terrestrial atmosphere and the some of the time-dependent systematic errors are treated by dividing the host star by a reference star at each wavelength and time step of the transit. More recently, Independent Component Analyses (ICA) have been used to remove systematic effects from the raw data of space-based observations (Waldmann 2014,2012; Morello et al.,2015,2016). ICA is a statistical method born from the ideas of the blind-source separation studies, which can be used to de-trend several independent source signals of a data set (Hyvarinen and Oja, 2000). One strength of this method is that it requires no additional prior knowledge of the system. Here, we present a study of the application of ICA to ground-based transit observations of extrasolar planets, which are affected by Earth's atmosphere. We analyze photometric data of two extrasolar planets, WASP-1b and GJ3470b, recorded by the 61" Kuiper Telescope at Stewart Observatory using the Harris B and U filters. The presentation will compare the light curve depths and their dispersions as derived from the ICA analysis to those derived by analyses that ratio of the host star to nearby reference stars.References: Waldmann, I.P. 2012 ApJ, 747, 12, Waldamann, I. P. 2014 ApJ, 780, 23; Morello G. 2015 ApJ, 806

  3. Design and Ground Calibration of the Helioseismic and Magnetic Imager (HMI) Instrument on the Solar Dynamics Observatory (SDO)

    Science.gov (United States)

    Schou, J.; Scherrer, P. H.; Bush, R. I.; Wachter, R.; Couvidat, S.; Rabello-Soares, M. C.; Bogart, R. S.; Hoeksema, J. T.; Liu, Y.; Duvall, T. L., Jr.; Akin, D. J.; Allard, B. A.; Miles, J. W.; Rairden, R.; Shine, R. A.; Tarbell, T. D.; Title, A. M.; Wolfson, C. J.; Elmore, D. F.; Norton, A. A..; Tomczyk, S.

    2012-01-01

    The Helioseismic and Magnetic Imager (HMI) investigation will study the solar interior using helioseismic techniques as well as the magnetic field near the solar surface. The HMI instrument is part of the Solar Dynamics Observatory (SDO) that was launched on 11 February 2010. The instrument is designed to measure the Doppler shift, intensity, and vector magnetic field at the solar photosphere using the 6173 Fe I absorption line. The instrument consists of a front-window filter, a telescope, a set of wave plates for polarimetry, an image-stabilization system, a blocking filter, a five-stage Lyot filter with one tunable element, two wide-field tunable Michelson interferometers, a pair of 4096(exo 2) pixel cameras with independent shutters, and associated electronics. Each camera takes a full-disk image roughly every 3.75 seconds giving an overall cadence of 45 seconds for the Doppler, intensity, and line-of-sight magnetic-field measurements and a slower cadence for the full vector magnetic field. This article describes the design of the HMI instrument and provides an overview of the pre-launch calibration efforts. Overviews of the investigation, details of the calibrations, data handling, and the science analysis are provided in accompanying articles.

  4. Comparison of aerosol optical depths from the Ozone Monitoring Instrument (OMI on Aura with results from airborne sunphotometry, other space and ground measurements during MILAGRO/INTEX-B

    Directory of Open Access Journals (Sweden)

    J. M. Livingston

    2009-09-01

    Full Text Available Airborne sunphotometer measurements are used to evaluate retrievals of extinction aerosol optical depth (AOD from spatially coincident and temporally near-coincident measurements by the Ozone Monitoring Instrument (OMI aboard the Aura satellite during the March 2006 Megacity Initiative-Local And Global Research Observations/Phase B of the Intercontinental Chemical Transport Experiment (MILAGRO/INTEX-B. The 14-channel NASA Ames Airborne Tracking Sunphotometer (AATS flew on nine missions over the Gulf of Mexico and four in or near the Mexico City area. Retrievals of AOD from near-coincident AATS and OMI measurements are compared for three flights over the Gulf of Mexico for flight segments when the aircraft flew at altitudes 60–70 m above sea level, and for one flight over the Mexico City area where the aircraft was restricted to altitudes ~320–800 m above ground level over the rural area and ~550–750 m over the city. OMI-measured top of atmosphere (TOA reflectances are routinely inverted to yield aerosol products such as AOD and aerosol absorption optical depth (AAOD using two different retrieval algorithms: a near-UV (OMAERUV and a multiwavelength (OMAERO technique. This study uses the archived Collection 3 data products from both algorithms. In particular, AATS and OMI AOD comparisons are presented for AATS data acquired in 20 OMAERUV retrieval pixels (15 over water and 19 OMAERO pixels (also 15 over water. At least four pixels for one of the over-water coincidences and all pixels for the over-land case were cloud-free. Coincident AOD retrievals from 17 pixels of the Moderate Resolution Imaging Spectroradiometer (MODIS aboard Aqua are available for two of the over-water flights and are shown to agree with AATS AODs to within root mean square (RMS differences of 0.00–0.06, depending on wavelength. Near-coincident ground-based AOD measurements from ground-based sun/sky radiometers operated as part of the Aerosol Robotic Network (AERONET

  5. Models of ionospheric VLF absorption of powerful ground based transmitters

    Science.gov (United States)

    Cohen, M. B.; Lehtinen, N. G.; Inan, U. S.

    2012-12-01

    Ground based Very Low Frequency (VLF, 3-30 kHz) radio transmitters play a role in precipitation of energetic Van Allen electrons. Initial analyses of the contribution of VLF transmitters to radiation belt losses were based on early models of trans-ionospheric propagation known as the Helliwell absorption curves, but some recent studies have found that the model overestimates (by 20-100 dB) the VLF energy reaching the magnetosphere. It was subsequently suggested that conversion of wave energy into electrostatic modes may be responsible for the error. We utilize a newly available extensive record of VLF transmitter energy reaching the magnetosphere, taken from the DEMETER satellite, and perform a direct comparison with a sophisticated full wave model of trans-ionospheric propagation. Although the model does not include the effect of ionospheric irregularities, it correctly predicts the average total power injected into the magnetosphere within several dB. The results, particularly at nighttime, appear to be robust against the variability of the ionospheric electron density. We conclude that the global effect of irregularity scattering on whistler mode conversion to quasi-electrostatic may be no larger than 6 dB.

  6. A review of instruments to measure interprofessional team-based primary care.

    Science.gov (United States)

    Shoemaker, Sarah J; Parchman, Michael L; Fuda, Kathleen Kerwin; Schaefer, Judith; Levin, Jessica; Hunt, Meaghan; Ricciardi, Richard

    2016-07-01

    Interprofessional team-based care is increasingly regarded as an important feature of delivery systems redesigned to provide more efficient and higher quality care, including primary care. Measurement of the functioning of such teams might enable improvement of team effectiveness and could facilitate research on team-based primary care. Our aims were to develop a conceptual framework of high-functioning primary care teams to identify and review instruments that measure the constructs identified in the framework, and to create a searchable, web-based atlas of such instruments (available at: http://primarycaremeasures.ahrq.gov/team-based-care/ ). Our conceptual framework was developed from existing frameworks, the teamwork literature, and expert input. The framework is based on an Input-Mediator-Output model and includes 12 constructs to which we mapped both instruments as a whole, and individual instrument items. Instruments were also reviewed for relevance to measuring team-based care, and characterized. Instruments were identified from peer-reviewed and grey literature, measure databases, and expert input. From nearly 200 instruments initially identified, we found 48 to be relevant to measuring team-based primary care. The majority of instruments were surveys (n = 44), and the remainder (n = 4) were observational checklists. Most instruments had been developed/tested in healthcare settings (n = 30) and addressed multiple constructs, most commonly communication (n = 42), heedful interrelating (n = 42), respectful interactions (n = 40), and shared explicit goals (n = 37). The majority of instruments had some reliability testing (n = 39) and over half included validity testing (n = 29). Currently available instruments offer promise to researchers and practitioners to assess teams' performance, but additional work is needed to adapt these instruments for primary care settings.

  7. ESPRESSO instrument control electronics: a PLC based distributed layout for a second generation instrument at ESO VLT

    Science.gov (United States)

    Baldini, V.; Cirami, R.; Coretti, I.; Cristiani, S.; Di Marcantonio, P.; Mannetta, M.; Santin, P.; Mégevand, D.; Zerbi, F.

    2014-07-01

    ESPRESSO is an ultra-stable fiber-fed spectrograph designed to combine incoherently the light coming from up to 4 Unit Telescopes of the ESO VLT. From the Nasmyth focus of each telescope the light, through an optical path, is fed by the Coudé Train subsystems to the Front End Unit placed in the Combined Coudé Laboratory. The Front End is composed by one arm for each telescope and its task is to convey the incoming light, after a calibration process, into the spectrograph fibers. To perform these operations a large number of functions are foreseen, like motorized stages, lamps, digital and analog sensors that, coupled with dedicated Technical CCDs (two per arms), allow to stabilize the incoming beam up to the level needed to exploit the ESPRESSO scientific requirements. The Instrument Control Electronics goal is to properly control all the functions in the Combined Coudé Laboratory and the spectrograph itself. It is fully based on a distributed PLC architecture, abandoning in this way the VME-based technology previously adopted for the ESO VLT instruments. In this paper we will describe the ESPRESSO Instrument Control Electronics architecture, focusing on the distributed layout and its interfaces with the other ESPRESSO subsystems.

  8. Reaching for the stars - New developments in ground-based astronomy

    CERN Document Server

    CERN. Geneva

    2015-01-01

    I will briefly review the state-of-the-art in ground-based astronomy - both on the telescope side and the instrument side. Interesting parallels can be drawn in cost, construction and operations with the particle physics facilities. I will then present some recent results in the two hottest topics in astronomy, driving the requests for more advanced facilities: exoplanets and the hunt for life beyond the solar system (calling for Extremely Large Telescope); and cosmology and the understanding of dark energy (calling for large survey telescopes). This will lead to a description of the latest telescope project developments on the ground: the on-going construction of the Large Synoptic Telescope on a quest to better understand dark energy, and the start of the construction of three Extremely Large Telescopes by European and US-led international consortia, hoping to find life on planets around nearby stars.   ATS Seminars Organisers: H. Burkhardt (BE), M. Modena (TE), T. Stora (EN) Coffee / tea will ...

  9. Ground Based Investigation of Electrostatic Accelerometer in HUST

    Science.gov (United States)

    Bai, Y.; Zhou, Z.

    2013-12-01

    High-precision electrostatic accelerometers with six degrees of freedom (DOF) acceleration measurement were successfully used in CHAMP, GRACE and GOCE missions which to measure the Earth's gravity field. In our group, space inertial sensor based on the capacitance transducer and electrostatic control technique has been investigated for test of equivalence principle (TEPO), searching non-Newtonian force in micrometer range, and satellite Earth's field recovery. The significant techniques of capacitive position sensor with the noise level at 2×10-7pF/Hz1/2 and the μV/Hz1/2 level electrostatic actuator are carried out and all the six servo loop controls by using a discrete PID algorithm are realized in a FPGA device. For testing on ground, in order to compensate one g earth's gravity, the fiber torsion pendulum facility is adopt to measure the parameters of the electrostatic controlled inertial sensor such as the resolution, and the electrostatic stiffness, the cross couple between different DOFs. A short distance and a simple double capsule equipment the valid duration about 0.5 second is set up in our lab for the free fall tests of the engineering model which can directly verify the function of six DOF control. Meanwhile, high voltage suspension method is also realized and preliminary results show that the horizontal axis of acceleration noise is about 10-8m/s2/Hz1/2 level which limited mainly by the seismic noise. Reference: [1] Fen Gao, Ze-Bing Zhou, Jun Luo, Feasibility for Testing the Equivalence Principle with Optical Readout in Space, Chin. Phys. Lett. 28(8) (2011) 080401. [2] Z. Zhu, Z. B. Zhou, L. Cai, Y. Z. Bai, J. Luo, Electrostatic gravity gradiometer design for the advanced GOCE mission, Adv. Sp. Res. 51 (2013) 2269-2276. [3] Z B Zhou, L Liu, H B Tu, Y Z Bai, J Luo, Seismic noise limit for ground-based performance measurements of an inertial sensor using a torsion balance, Class. Quantum Grav. 27 (2010) 175012. [4] H B Tu, Y Z Bai, Z B Zhou, L Liu, L

  10. Probing Pluto's Atmosphere Using Ground-Based Stellar Occultations

    Science.gov (United States)

    Sicardy, Bruno; Rio de Janeiro Occultation Team, Granada Team, International Occultation and Timing Association, Royal Astronomical Society New Zealand Occultation Section, Lucky Star associated Teams

    2016-10-01

    Over the last three decades, some twenty stellar occultations by Pluto have been monitored from Earth. They occur when the dwarf planet blocks the light from a star for a few minutes as it moves on the sky. Such events led to the hint of a Pluto's atmosphere in 1985, that was fully confirmed during another occultation in 1988, but it was only in 2002 that a new occultation could be recorded. From then on, the dwarf planet started to move in front of the galactic center, which amplified by a large factor the number of events observable per year.Pluto occultations are essentially refractive events during which the stellar rays are bent by the tenuous atmosphere, causing a gradual dimming of the star. This provides the density, pressure and temperature profiles of the atmosphere from a few kilometers above the surface up to about 250 km altitude, corresponding respectively to pressure levels of about 10 and 0.1 μbar. Moreover, the extremely fine spatial resolution (a few km) obtained through this technique allows the detection of atmospheric gravity waves, and permits in principle the detection of hazes, if present.Several aspects make Pluto stellar occultations quite special: first, they are the only way to probe Pluto's atmosphere in detail, as the dwarf planet is far too small on the sky and the atmosphere is far too tenuous to be directly imaged from Earth. Second, they are an excellent example of participative science, as many amateurs have been able to record those events worldwide with valuable scientific returns, in collaboration with professional astronomers. Third, they reveal Pluto's climatic changes on decade-scales and constrain the various seasonal models currently explored.Finally, those observations are fully complementary to space exploration, in particular with the New Horizons (NH) mission. I will show how ground-based occultations helped to better calibrate some NH profiles, and conversely, how NH results provide some key boundary conditions

  11. Ground-based analysis of volcanic ash plumes using a new multispectral thermal infrared camera approach

    Science.gov (United States)

    Williams, D.; Ramsey, M. S.

    2015-12-01

    Volcanic plumes are complex mixtures of mineral, lithic and glass fragments of varying size, together with multiple gas species. These plumes vary in size dependent on a number of factors, including vent diameter, magma composition and the quantity of volatiles within a melt. However, determining the chemical and mineralogical properties of a volcanic plume immediately after an eruption is a great challenge. Thermal infrared (TIR) satellite remote sensing of these plumes is routinely used to calculate the volcanic ash particle size variations and sulfur dioxide concentration. These analyses are commonly performed using high temporal, low spatial resolution satellites, which can only reveal large scale trends. What is lacking is a high spatial resolution study specifically of the properties of the proximal plumes. Using the emissive properties of volcanic ash, a new method has been developed to determine the plume's particle size and petrology in spaceborne and ground-based TIR data. A multispectral adaptation of a FLIR TIR camera has been developed that simulates the TIR channels found on several current orbital instruments. Using this instrument, data of volcanic plumes from Fuego and Santiaguito volcanoes in Guatemala were recently obtained Preliminary results indicate that the camera is capable of detecting silicate absorption features in the emissivity spectra over the TIR wavelength range, which can be linked to both mineral chemistry and particle size. It is hoped that this technique can be expanded to isolate different volcanic species within a plume, validate the orbital data, and ultimately to use the results to better inform eruption dynamics modelling.

  12. Seven years of middle-atmospheric CO in the Arctic by ground based radiometry

    Science.gov (United States)

    Ryan, Niall; Palm, Mathias; Raffalski, Uwe; Larsson, Richard; Notholt, Justus

    2016-04-01

    During polar winter, carbon monoxide (CO) is a well-suited tracer for middle atmospheric dynamics and for studying the polar vortex boundary: In polar night the chemical reactions involving atmospheric carbon monoxide are negligible due to the lack of sunlight and, as a result, the gas exhibits strong vertical and horizontal gradients in the stratosphere and mesosphere. Due to the upcoming likely gap in satellite profiling instruments, and in order to maintain a long-term global record of atmospheric trace gas concentrations, current and future satellite missions must be inter-calibrated using measurements from ground-based instruments around the globe. The Kiruna Microwave Radiometer (KIMRA), installed at the Swedish Institute of Space Physics, Kiruna, Sweden (67.8 N, 20.4 E), has been measuring microwave spectra of emissions from atmospheric CO since 2007. This contribution presents the CO concentration record which has been retrieved from KIMRA measurements using different temperature datasets: measurements from the Defense Meteorological Satellite Program - F18 and model output from the European Centre for Medium-Range Weather Forecasts. The concentration profiles, retrieved between 40 and 80 km altitude, are compared to data from the Microwave Limb Sounder on the Aura satellite and are used to examine the concentration gradient across the polar vortex edge.

  13. Assessment of the quality of OSIRIS mesospheric temperatures using satellite and ground-based measurements

    Directory of Open Access Journals (Sweden)

    P. E. Sheese

    2012-12-01

    Full Text Available The Optical Spectrograph and InfraRed Imaging System (OSIRIS on the Odin satellite is currently in its 12th year of observing the Earth's limb. For the first time, continuous temperature profiles extending from the stratopause to the upper mesosphere have been derived from OSIRIS measurements of Rayleigh-scattered sunlight. Through most of the mesosphere, OSIRIS temperatures are in good agreement with coincident temperature profiles derived from other satellite and ground-based measurements. In the altitude region of 55–80 km, OSIRIS temperatures are typically within 4–5 K of those from the SABER, ACE-FTS, and SOFIE instruments on the TIMED, SciSat-I, and AIM satellites, respectively. The mean differences between individual OSIRIS profiles and those of the other satellite instruments are typically within the combined uncertainties and previously reported biases. OSIRIS temperatures are typically within 2 K of those from the University of Western Ontario's Purple Crow Lidar in the altitude region of 52–79 km, where the mean differences are within combined uncertainties. Near 84 km, OSIRIS temperatures exhibit a cold bias of 10–15 K, which is due to a cold bias in OSIRIS O2 A-band temperatures at 85 km, the upper boundary of the Rayleigh-scatter derived temperatures; and near 48 km OSIRIS temperatures exhibit a cold bias of 5–15 K, which is likely due to multiple-scatter effects that are not taken into account in the retrieval.

  14. Combined ground-based optical support for the aurora (DELTA) sounding rocket campaign

    Science.gov (United States)

    Griffin, Eoghan; Kosch, Mike; Aruliah, Anasuya; Kavanagh, Andrew; McWhirter, Ian; Senior, Andrew; Ford, Elaina; Davis, Chris; Abe, Takumi; Kurihara, Junichi; Kauristie, Kirsti; Ogawa, Yasunobu

    2006-09-01

    The Japan Aerospace Exploration Agency (JAXA) DELTA rocket experiment, successfully launched from Andøya at 0033 UT on December 13, 2004, supported by ground based optical instruments, primarily 2 Fabry- Perot Interferometers (FPIs) located at Skibotn, Norway (69.3°N, 20.4°E) and the KEOPS Site, Esrange, Kiruna, Sweden (67.8°N, 20.4°E). Both these instruments sampled the 557.7 nm lower thermosphere atomic oxygen emission and provided neutral temperatures and line-of-sight wind velocities, with deduced vector wind patterns over each site. All sky cameras allow contextual auroral information to be acquired. The proximity of the sites provided overlapping fields of view, adjacent to the trajectory of the DELTA rocket. This allowed independent verification of the absolute temperatures in the relatively quiet conditions early in the night, especially important given the context provided by co-located EISCAT ion temperature measurements which allow investigation of the likely emission altitude of the passive FPI measurements. The results demonstrate that this altitude changes from 120 km pre-midnight to 115 km post-midnight. Within this large scale context the results from the FPIs also demonstrate smaller scale structure in neutral temperatures, winds and intensities consistent with localised heating. These results present a challenge to the representation of thermospheric variability for the existing models of the region.

  15. Improved ground-based FTS measurement for column abundance CO2 retrievals(Conference Presentation)

    Science.gov (United States)

    Goo, Tae-Young

    2016-10-01

    The National Institute of Meteorological Sciences has operated a ground-based Fourier Transform Spectrometer (FTS) at Anmyeondo, Korea since December 2012. Anmyeondo FTS site is a designated operational station of Total Carbon Column Observing Network (TCCON) and belongs to regional Global Atmosphere Watch observatory. A Bruker IFS-125HR model, which has a significantly high spectral resolution by 0.02 cm-1, is employed and instrument specification is almost same as the TCCON configuration. such as a spectrum range of 3,800 16,000 cm-1, a resolution of 1 cm-1, InGaAs and Si-Diode detectors and CaF2 beam splitter. It is found that measured spectra have a good agreement with simulated spectra. In order to improve the spectral accuracy and stability, The Operational Automatic System for Intensity of Sunray (OASIS) has been developed. The OASIS can provide consistent photon energy optimized to detector range by controlling the diameter of solar beam reflected from the mirror of suntracker. As a result, monthly modulation efficiency (ME), which indicates the spectral accuracy of FTS measurement, has been recorded the vicinity of 99.9% since Feb 2015. The ME of 98% is regarded as the error of 0.1% in the ground-based in-situ CO2 measurement. Total column abundances of CO2 and CH4 during 2015 are estimated by using GGG v14 and compared with ground-based in-situ CO2 and CH4 measurements at the height of 86 m above sea level. The seasonality of CO2 is well captured by both FTS and in-situ measurements while there is considerable difference on the amplitude of CO2 seasonal variation due to the insensitivity of column CO2 to the surface carbon cycle dynamics in nature as well as anthropogenic sources. Total column CO2 and CH4 approximately vary from 395 ppm to 405 ppm and from 1.82 ppm to 1.88 ppm, respectively. It should be noted that few measurements obtained in July to August because of a lot of cloud and fog. It is found that enhancement of CH4 from the FTS at Anmyeondo

  16. Instrumental Genesis in GeoGebra Based Board Game Design

    DEFF Research Database (Denmark)

    Misfeldt, Morten

    2013-01-01

    for teaching skills with GeoGebra, as well as an entrepreneurial attitude towards mathematics. Using the instrumental approach I discuss how open ended transdisciplinary design activities can support instrumental genesis, by considering the extent to which the pupils address mathematical knowledge......In this paper I address the use of digital tools (GeoGebra) in open ended design activities, with primary school children. I present results from the research and development project “Creative Digital Mathematics”, which aims to use the pupil’s development of mathematical board games as a vehicle...... in their work with GeoGebra and how they relate their work with GeoGebra and mathematics to fellow pupils and real life situations. The results show that pupils’ consider development of board games as meaningful mathematical activity, and that they develop skills with GeoGebra, furthermore the pupils considers...

  17. Musical Instrument Classification Based on Nonlinear Recurrence Analysis and Supervised Learning

    Directory of Open Access Journals (Sweden)

    R.Rui

    2013-04-01

    Full Text Available In this paper, the phase space reconstruction of time series produced by different instruments is discussed based on the nonlinear dynamic theory. The dense ratio, a novel quantitative recurrence parameter, is proposed to describe the difference of wind instruments, stringed instruments and keyboard instruments in the phase space by analyzing the recursive property of every instrument. Furthermore, a novel supervised learning algorithm for automatic classification of individual musical instrument signals is addressed deriving from the idea of supervised non-negative matrix factorization (NMF algorithm. In our approach, the orthogonal basis matrix could be obtained without updating the matrix iteratively, which NMF is unable to do. The experimental results indicate that the accuracy of the proposed method is improved by 3% comparing with the conventional features in the individual instrument classification.

  18. Ground Motion Prediction Trends For Eastern North America Based on the Next Generation Attenuation East Ground Motion Database

    Science.gov (United States)

    Cramer, C. H.; Kutliroff, J.; Dangkua, D.

    2010-12-01

    A five-year Next Generation Attenuation (NGA) East project to develop new ground motion prediction equations for stable continental regions (SCRs), including eastern North America (ENA), has begun at the Pacific Earthquake Engineering Research (PEER) Center funded by the Nuclear Regulatory Commission (NRC), the U.S. Geological Survey (USGS), the Electric Power Research Institute (EPRI), and the Department of Energy (DOE). The initial effort focused on database design and collection of appropriate M>4 ENA broadband and accelerograph records to populate the database. Ongoing work has focused on adding records from smaller ENA earthquakes and from other SCRs such as Europe, Australia, and India. Currently, over 6500 horizontal and vertical component records from 60 ENA earthquakes have been collected and prepared (instrument response removed, filtering to acceptable-signal band, determining peak and spectral parameter values, quality assurance, etc.) for the database. Geologic Survey of Canada (GSC) strong motion recordings, previously not available, have also been added to the NGA East database. The additional earthquakes increase the number of ground motion recordings in the 10 - 100 km range, particularly from the 2008 M5.2 Mt. Carmel, IL event, and the 2005 M4.7 Riviere du Loup and 2010 M5.0 Val des Bois earthquakes in Quebec, Canada. The goal is to complete the ENA database and make it available in 2011 followed by a SCR database in 2012. Comparisons of ground motion observations from four recent M5 ENA earthquakes with current ENA ground motion prediction equations (GMPEs) suggest that current GMPEs, as a group, reasonably agree with M5 observations at short periods, particularly at distances less than 200 km. However, at one second, current GMPEs over predict M5 ground motion observations. The 2001 M7.6 Bhuj, India, earthquake provides some constraint at large magnitudes, as geology and regional attenuation is analogous to ENA. Cramer and Kumar, 2003, have

  19. Space-borne detection of volcanic carbon dioxide anomalies: The importance of ground-based validation networks

    Science.gov (United States)

    Schwandner, F. M.; Carn, S. A.; Corradini, S.; Merucci, L.; Salerno, G.; La Spina, A.

    2012-04-01

    We have investigated the feasibility of space-borne detection of volcanic carbon dioxide (CO2) anomalies, and their integration with ground-based observations. Three goals provide motivation to their integration: (a) development of new volcano monitoring techniques, with better spatial and temporal coverage, because pre-eruptive volcanic CO2 emissions are potentially the earliest available indicators of volcanic unrest; (b) improvement the currently very poor global CO2 source strength inventory for volcanoes, and (c) use of volcanic CO2 emissions for high altitude strong point source emission and dispersion studies. (1) Feasibility of space-borne detection of volcanic CO2 anomalies. Volcanoes are highly variable but continuous CO2 emitters, distributed globally, and emissions often occur at high altitudes. To detect strong point sources of CO2 from space, several hurdles have to be overcome: orographic clouds, unknown dispersion behavior, a high CO2 background in the troposphere, and sparse data coverage from existing satellite sensors. These obstacles can be overcome by a small field of view, enhanced spectral resolving power, and by employing repeat target mode observation strategies. The Japanese GOSAT instrument has been operational since January 2009, producing CO2 total column measurements with a repeat cycle of 3 days and a field of view of 10km. GOSAT thus has the potential to provide spatially integrated data for entire volcanic edifices, especially in target mode. Since summer 2010 we have conducted repeated target mode observations of over 20 persistently active global volcanoes including Etna (Italy), Erta Ale (Ethiopia), and Ambrym (Vanuatu), using L2 GOSAT FTS SWIR data. One of our best-studied test cases is Mt. Etna on Sicily (Italy), which reawakened in 2011 after a period of quiescence and produced a sequence of eruptive activities including lava fountaining events, coinciding with target-mode GOSAT observations conducted there since 2010. For the

  20. Validation of five years (2003–2007 of SCIAMACHY CO total column measurements using ground-based spectrometer observations

    Directory of Open Access Journals (Sweden)

    A. M. Poberovskii

    2010-10-01

    Full Text Available This paper presents a validation study of SCanning Imaging Absorption spectroMeter for Atmospheric CHartographY (SCIAMACHY carbon monoxide (CO total column measurements from the Iterative Maximum Likelihood Method (IMLM algorithm using ground-based spectrometer observations from twenty surface stations for the five year time period of 2003–2007. Overall we find a good agreement between SCIAMACHY and ground-based observations for both mean values as well as seasonal variations. For high-latitude Northern Hemisphere stations absolute differences between SCIAMACHY and ground-based measurements are close to or fall within the SCIAMACHY CO 2σ precision of 0.2 × 1018 molecules/cm2 (∼10% indicating that SCIAMACHY can observe CO accurately at high Northern Hemisphere latitudes. For Northern Hemisphere mid-latitude stations the validation is complicated due to the vicinity of emission sources for almost all stations, leading to higher ground-based measurements compared to SCIAMACHY CO within its typical sampling area of 8° × 8°. Comparisons with Northern Hemisphere mountain stations are hampered by elevation effects. After accounting for these effects, the validation provides satisfactory results. At Southern Hemisphere mid- to high latitudes SCIAMACHY is systematically lower than the ground-based measurements for 2003 and 2004, but for 2005 and later years the differences between SCIAMACHY and ground-based measurements fall within the SCIAMACHY precision. The 2003–2004 bias is consistent with previously reported results although its origin remains under investigation. No other systematic spatial or temporal biases could be identified based on the validation presented in this paper. Validation results are robust with regard to the choices of the instrument-noise error filter, sampling area, and time averaging required for the validation of SCIAMACHY CO total column measurements. Finally, our results show that the spatial coverage of the ground-based

  1. Observing Tsunamis in the Ionosphere Using Ground Based GPS Measurements

    Science.gov (United States)

    Galvan, D. A.; Komjathy, A.; Song, Y. Tony; Stephens, P.; Hickey, M. P.; Foster, J.

    2011-01-01

    Ground-based Global Positioning System (GPS) measurements of ionospheric Total Electron Content (TEC) show variations consistent with atmospheric internal gravity waves caused by ocean tsunamis following recent seismic events, including the Tohoku tsunami of March 11, 2011. We observe fluctuations correlated in time, space, and wave properties with this tsunami in TEC estimates processed using JPL's Global Ionospheric Mapping Software. These TEC estimates were band-pass filtered to remove ionospheric TEC variations with periods outside the typical range of internal gravity waves caused by tsunamis. Observable variations in TEC appear correlated with the Tohoku tsunami near the epicenter, at Hawaii, and near the west coast of North America. Disturbance magnitudes are 1-10% of the background TEC value. Observations near the epicenter are compared to estimates of expected tsunami-driven TEC variations produced by Embry Riddle Aeronautical University's Spectral Full Wave Model, an atmosphere-ionosphere coupling model, and found to be in good agreement. The potential exists to apply these detection techniques to real-time GPS TEC data, providing estimates of tsunami speed and amplitude that may be useful for future early warning systems.

  2. Tissue Engineering of Cartilage on Ground-Based Facilities

    Science.gov (United States)

    Aleshcheva, Ganna; Bauer, Johann; Hemmersbach, Ruth; Egli, Marcel; Wehland, Markus; Grimm, Daniela

    2016-06-01

    Investigations under simulated microgravity offer the opportunity for a better understanding of the influence of altered gravity on cells and the scaffold-free three-dimensional (3D) tissue formation. To investigate the short-term influence, human chondrocytes were cultivated for 2 h, 4 h, 16 h, and 24 h on a 2D Fast-Rotating Clinostat (FRC) in DMEM/F-12 medium supplemented with 10 % FCS. We detected holes in the vimentin network, perinuclear accumulations of vimentin after 2 h, and changes in the chondrocytes shape visualised by F-actin staining after 4 h of FRC-exposure. Scaffold-free cultivation of chondrocytes for 7 d on the Random Positioning Machine (RPM), the FRC and the Rotating Wall Vessel (RWV) resulted in spheroid formation, a phenomenon already known from spaceflight experiments with chondrocytes (MIR Space Station) and thyroid cancer cells (SimBox/Shenzhou-8 space mission). The experiments enabled by the ESA-CORA-GBF programme gave us an optimal opportunity to study gravity-related cellular processes, validate ground-based facilities for our chosen cell system, and prepare long-term experiments under real microgravity conditions in space

  3. Theoretical validation of ground-based microwave ozone observations

    Directory of Open Access Journals (Sweden)

    P. Ricaud

    Full Text Available Ground-based microwave measurements of the diurnal and seasonal variations of ozoneat 42±4.5 and 55±8 km are validated by comparing with results from a zero-dimensional photochemical model and a two-dimensional (2D chemical/radiative/dynamical model, respectively. O3 diurnal amplitudes measured in Bordeaux are shown to be in agreement with theory to within 5%. For the seasonal analysis of O3 variation, at 42±4.5 km, the 2D model underestimates the yearly averaged ozone concentration compared with the measurements. A double maximum oscillation (~3.5% is measured in Bordeaux with an extended maximum in September and a maximum in February, whilst the 2D model predicts only a single large maximum (17% in August and a pronounced minimum in January. Evidence suggests that dynamical transport causes the winter O3 maximum by propagation of planetary waves, phenomena which are not explicitly reproduced by the 2D model. At 55±8 km, the modeled yearly averaged O3 concentration is in very good agreement with the measured yearly average. A strong annual oscillation is both measured and modeled with differences in the amplitude shown to be exclusively linked to temperature fields.

  4. Atmospheric Refraction Path Integrals in Ground-Based Interferometry

    CERN Document Server

    Mathar, R J

    2004-01-01

    The basic effect of the earth's atmospheric refraction on telescope operation is the reduction of the true zenith angle to the apparent zenith angle, associated with prismatic aberrations due to the dispersion in air. If one attempts coherent superposition of star images in ground-based interferometry, one is in addition interested in the optical path length associated with the refracted rays. In a model of a flat earth, the optical path difference between these is not concerned as the translational symmetry of the setup means no net effect remains. Here, I evaluate these interferometric integrals in the more realistic arrangement of two telescopes located on the surface of a common earth sphere and point to a star through an atmosphere which also possesses spherical symmetry. Some focus is put on working out series expansions in terms of the small ratio of the baseline over the earth radius, which allows to bypass some numerics which otherwise is challenged by strong cancellation effects in building the opti...

  5. Experiments on a Ground-Based Tomographic Synthetic Aperture Radar

    Directory of Open Access Journals (Sweden)

    Hoonyol Lee

    2016-08-01

    Full Text Available This paper presents the development and experiment of three-dimensional image formation by using a ground-based tomographic synthetic aperture radar (GB-TomoSAR system. GB-TomoSAR formulates two-dimensional synthetic aperture by the motion of antennae, both in azimuth and vertical directions. After range compression, three-dimensional image focusing is performed by applying Deramp-FFT (Fast Fourier Transform algorithms, both in azimuth and vertical directions. Geometric and radiometric calibrations were applied to make an image cube, which is then projected into range-azimuth and range-vertical cross-sections for visualization. An experiment with a C-band GB-TomoSAR system with a scan length of 2.49 m and 1.86 m in azimuth and vertical-direction, respectively, shows distinctive three-dimensional radar backscattering of stable buildings and roads with resolutions similar to the theoretical values. Unstable objects such as trees and moving cars generate severe noise due to decorrelation during the eight-hour image-acquisition time.

  6. Satellite Type Estination from Ground-based Photometric Observation

    Science.gov (United States)

    Endo, T.; Ono, H.; Suzuki, J.; Ando, T.; Takanezawa, T.

    2016-09-01

    The optical photometric observation is potentially a powerful tool for understanding of the Geostationary Earth Orbit (GEO) objects. At first, we measured in laboratory the surface reflectance of common satellite materials, for example, Multi-layer Insulation (MLI), mono-crystalline silicon cells, and Carbon Fiber Reinforced Plastic (CFRP). Next, we calculated visual magnitude of a satellite by simplified shape and albedo. In this calculation model, solar panels have dimensions of 2 by 8 meters, and the bus area is 2 meters squared with measured optical properties described above. Under these conditions, it clarified the brightness can change the range between 3 and 4 magnitudes in one night, but color index changes only from 1 to 2 magnitudes. Finally, we observed the color photometric data of several GEO satellites visible from Japan multiple times in August and September 2014. We obtained that light curves of GEO satellites recorded in the B and V bands (using Johnson filters) by a ground-base optical telescope. As a result, color index changed approximately from 0.5 to 1 magnitude in one night, and the order of magnitude was not changed in all cases. In this paper, we briefly discuss about satellite type estimation using the relation between brightness and color index obtained from the photometric observation.

  7. Ground-based measurements of UV Index (UVI at Helwan

    Directory of Open Access Journals (Sweden)

    H. Farouk

    2012-12-01

    Full Text Available On October 2010 UV Index (UVI ground-based measurements were carried out by weather station at solar laboratory in NRIAG. The daily variation has maximum values in spring and summer days, while minimum values in autumn and winter days. The low level of UVI between 2.55 and 2.825 was found in December, January and February. The moderate level of UVI between 3.075 and 5.6 was found in March, October and November. The high level of UVI between 6.7 and 7.65 was found in April, May and September. The very high level of UVI between 8 and 8.6 was found in June, July and August. High level of radiation over 6 months per year including 3 months with a very high level UVI. According to the equation {UVI=a[SZA]b} the UVI increases with decreasing SZA by 82% on a daily scale and 88% on a monthly scale. Helwan exposure to a high level of radiation over 6 months per year including 3 months with a very high level UVI, so it is advisable not to direct exposure to the sun from 11 am to 2:00 pm.

  8. Estimates of the Planet Yield from Ground-Based High-Contrast Imaging Observations as a Function of Stellar Mass

    CERN Document Server

    Crepp, Justin R

    2011-01-01

    We use Monte Carlo simulations to estimate the number of extrasolar planets that are directly detectable in the solar-neighborhood using current and forthcoming high-contrast imaging instruments. Our calculations take into account the important factors that govern the likelihood for imaging a planet, including the statistical properties of nearby stars, correlations between star and planet properties, observational effects, and selection criteria. We consider several different ground-based surveys and express the resulting yields as a function of stellar mass. Selecting targets based on their youth and visual brightness, we find that strong correlations between star mass and planet properties are required to reproduce high-contrast imaging results to date. Using the most recent empirical findings for the occurrence rate of planets from RV surveys, our simulations indicate that extrapolation of the Doppler planet population to separations accessible to high-contrast instruments provides excellent agreement bet...

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

    Science.gov (United States)

    Turner, Emma C.; Withington, Stafford; Newnham, David A.; Wadhams, Peter; Jones, Anna E.; Clancy, Robin

    2016-11-01

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

  10. Ground-based photometry of the 21-day Neptune HD 106315c

    Science.gov (United States)

    Lendl, M.; Ehrenreich, D.; Turner, O. D.; Bayliss, D.; Blanco-Cuaresma, S.; Giles, H.; Bouchy, F.; Marmier, M.; Udry, S.

    2017-07-01

    Space-based transit surveys such as K2 and the Transiting Exoplanets Survey Satellite (TESS) allow the detection of small transiting planets with orbital periods greater than 10 days. Few of these warm Neptunes are currently known around stars bright enough to allow for detailed follow-up observations dedicated to their atmospheric characterization. The 21-day period and 3.95 R⊕ planet HD 106315c has been discovered by K2 based on the observation of two of its transits. We observed HD 106315 using the 1.2 m Euler telescope equipped with the EulerCam camera on two occasions to confirm the transit using broadband photometry and refine the planetary period. Based on two observed transits of HD 106315c, we detect its 1 mmag transit and obtain a precise measurement of the planetary ephemerides, which are critical for planning further follow-up observations. We used the attained precision together with the predicted yield from the TESS mission to evaluate the potential for ground-based confirmation of Neptune-sized planets found by TESS. We find that one-meter class telescopes on the ground equipped with precise photometers could substantially contribute to the follow-up of 162 TESS candidates orbiting stars with magnitudes of V ≤ 14. Of these candidates, 74 planets orbit stars with V ≤ 12 and 12 planets orbit V ≤ 10, which makes them high-priority objects for atmospheric characterization with high-end instrumentation. The photometric time series data are only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (http://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/603/L5

  11. Ground-based monitoring of solar radiation in Moldova

    Science.gov (United States)

    Aculinin, Alexandr; Smicov, Vladimir

    2010-05-01

    Integrated measurements of solar radiation in Kishinev, Moldova have been started by Atmospheric Research Group (ARG) at the Institute of Applied Physics from 2003. Direct, diffuse and total components of solar and atmospheric long-wave radiation are measured by using of the radiometric complex at the ground-based solar radiation monitoring station. Measurements are fulfilled at the stationary and moving platforms equipped with the set of 9 broadband solar radiation sensors overlapping wavelength range from UV-B to IR. Detailed description of the station can be found at the site http://arg.phys.asm.md. Ground station is placed in an urban environment of Kishinev city (47.00N; 28.56E). Summary of observation data acquired at the station in the course of short-term period from 2004 to 2009 are presented below. Solar radiation measurements were fulfilled by using CM11(280-3000 nm) and CH1 sensors (Kipp&Zonen). In the course of a year maximum and minimum of monthly sums of total radiation was ~706.4 MJm-2 in June and ~82.1MJm-2 in December, respectively. Monthly sums of direct solar radiation (on horizontal plane) show the maximum and minimum values of the order ~456.9 MJm-2 in July and ~25.5MJm-2 in December, respectively. In an average, within a year should be marked the predominance of direct radiation over the scattered radiation, 51% and 49%, respectively. In the course of a year, the percentage contribution of the direct radiation into the total radiation is ~55-65% from May to September. In the remaining months, the percentage contribution decreases and takes the minimum value of ~ 28% in December. In an average, annual sum of total solar radiation is ~4679.9 MJm-2. For the period from April to September accounts for ~76% of the annual amount of total radiation. Annual sum of sunshine duration accounts for ~2149 hours, which is of ~ 48% from the possible sunshine duration. In an average, within a year maximum and minimum of sunshine duration is ~ 304 hours in

  12. Comparing multiple model-derived aerosol optical properties to spatially collocated ground-based and satellite measurements

    Science.gov (United States)

    Ocko, Ilissa B.; Ginoux, Paul A.

    2017-04-01

    Anthropogenic aerosols are a key factor governing Earth's climate and play a central role in human-caused climate change. However, because of aerosols' complex physical, optical, and dynamical properties, aerosols are one of the most uncertain aspects of climate modeling. Fortunately, aerosol measurement networks over the past few decades have led to the establishment of long-term observations for numerous locations worldwide. Further, the availability of datasets from several different measurement techniques (such as ground-based and satellite instruments) can help scientists increasingly improve modeling efforts. This study explores the value of evaluating several model-simulated aerosol properties with data from spatially collocated instruments. We compare aerosol optical depth (AOD; total, scattering, and absorption), single-scattering albedo (SSA), Ångström exponent (α), and extinction vertical profiles in two prominent global climate models (Geophysical Fluid Dynamics Laboratory, GFDL, CM2.1 and CM3) to seasonal observations from collocated instruments (AErosol RObotic NETwork, AERONET, and Cloud-Aerosol Lidar with Orthogonal Polarization, CALIOP) at seven polluted and biomass burning regions worldwide. We find that a multi-parameter evaluation provides key insights on model biases, data from collocated instruments can reveal underlying aerosol-governing physics, column properties wash out important vertical distinctions, and improved models does not mean all aspects are improved. We conclude that it is important to make use of all available data (parameters and instruments) when evaluating aerosol properties derived by models.

  13. Signal Processing Techniques for Silicon Drift Detector Based X-Ray Spectrometer for Planatary Instruments

    Science.gov (United States)

    Patel, A.; Shanmugam, M.; Ladiya, T.

    2016-10-01

    We are developing SDD based x-ray spectrometer using various pulse height analysis techniques. This study will help to identify the proper processing technique based on instrument specifications which can be used for future scientific missions.

  14. GVT-Based Ground Flutter Test without Wind Tunnel Project

    Data.gov (United States)

    National Aeronautics and Space Administration — ZONA Technology, Inc (ZONA) and Arizona State University (ASU) propose a R&D effort to develop a ground flutter testing system without wind tunnel, called the...

  15. GVT-Based Ground Flutter Test without Wind Tunnel Project

    Data.gov (United States)

    National Aeronautics and Space Administration — ZONA Technology, Inc (ZONA) and Arizona State University (ASU) propose a R&D effort to further develop the ground flutter testing system in place of a wind...

  16. System of gait analysis based on ground reaction force assessment

    Directory of Open Access Journals (Sweden)

    František Vaverka

    2015-12-01

    Full Text Available Background: Biomechanical analysis of gait employs various methods used in kinematic and kinetic analysis, EMG, and others. One of the most frequently used methods is kinetic analysis based on the assessment of the ground reaction forces (GRF recorded on two force plates. Objective: The aim of the study was to present a method of gait analysis based on the assessment of the GRF recorded during the stance phase of two steps. Methods: The GRF recorded with a force plate on one leg during stance phase has three components acting in directions: Fx - mediolateral, Fy - anteroposterior, and Fz - vertical. A custom-written MATLAB script was used for gait analysis in this study. This software displays instantaneous force data for both legs as Fx(t, Fy(t and Fz(t curves, automatically determines the extremes of functions and sets the visual markers defining the individual points of interest. Positions of these markers can be easily adjusted by the rater, which may be necessary if the GRF has an atypical pattern. The analysis is fully automated and analyzing one trial takes only 1-2 minutes. Results: The method allows quantification of temporal variables of the extremes of the Fx(t, Fy(t, Fz(t functions, durations of the braking and propulsive phase, duration of the double support phase, the magnitudes of reaction forces in extremes of measured functions, impulses of force, and indices of symmetry. The analysis results in a standardized set of 78 variables (temporal, force, indices of symmetry which can serve as a basis for further research and diagnostics. Conclusions: The resulting set of variable offers a wide choice for selecting a specific group of variables with consideration to a particular research topic. The advantage of this method is the standardization of the GRF analysis, low time requirements allowing rapid analysis of a large number of trials in a short time, and comparability of the variables obtained during different research measurements.

  17. Development and use of compact instruments for tropospheric investigations based on optical spectroscopy from mobile platforms

    OpenAIRE

    Merlaud, Alexis

    2013-01-01

    This thesis presents the development of four different remote-sensing instruments dedicated to atmospheric research and their use in field campaigns between 2008 and 2012. The instruments are based on uv-visible spectrometers and installed respectively on a scientific aircraft (Safire ATR-42), ultralight aircraft, and cars. One of the instruments is targeted to operate from an Unmanned Aerial Vehicle (UAV). The Differential Optical Absorption Spectroscopy (DOAS) technique is used to quantify ...

  18. LXI instrument development platform based on an open embedded operating system

    Institute of Scientific and Technical Information of China (English)

    Yu Wilson

    2007-01-01

    This paper introduces the architecture and components of LXI instrument development platform based on an open embedded operating system, which is a modular and configurable platform. The platform is a total solution to develop LXI instrument modules and systems. On the other hand, it also supports other types of instrument development. This is a generic and efficient platform. At the end, this paper addresses the technical tends,challenges, and recommends solutions.

  19. [Design and implementation of pulse instrument based on DSP].

    Science.gov (United States)

    Jiao, Qiyu; Pang, Chunying

    2013-03-01

    The Traditional Chinese Medical Pulse Instrument uses the HKG-07B infrared pulse sensor to get pulse signal from the body. It makes full use of the TMS320VC5402 chip to realize time-frequency domain parameters extracting, classification and identification of the pulse signal. The system can store a plenty of pulse signal and realize data communication with the PC via the USB interface. According to acquisition and classification of pulse signal experiments of 200 subjects, the results show that the recognition rate of pulse signal can reach to 87.4%. It is applicable to the clinical diagnosis and detection of the pulse signal and home healthcare.

  20. Evaluation of fault-normal/fault-parallel directions rotated ground motions for response history analysis of an instrumented six-story building

    Science.gov (United States)

    Kalkan, Erol; Kwong, Neal S.

    2012-01-01

    According to regulatory building codes in United States (for example, 2010 California Building Code), at least two horizontal ground-motion components are required for three-dimensional (3D) response history analysis (RHA) of buildings. For sites within 5 km of an active fault, these records should be rotated to fault-normal/fault-parallel (FN/FP) directions, and two RHA analyses should be performed separately (when FN and then FP are aligned with the transverse direction of the structural axes). It is assumed that this approach will lead to two sets of responses that envelope the range of possible responses over all nonredundant rotation angles. This assumption is examined here using a 3D computer model of a six-story reinforced-concrete instrumented building subjected to an ensemble of bidirectional near-fault ground motions. Peak responses of engineering demand parameters (EDPs) were obtained for rotation angles ranging from 0° through 180° for evaluating the FN/FP directions. It is demonstrated that rotating ground motions to FN/FP directions (1) does not always lead to the maximum responses over all angles, (2) does not always envelope the range of possible responses, and (3) does not provide maximum responses for all EDPs simultaneously even if it provides a maximum response for a specific EDP.

  1. Ground-based imaging remote sensing of ice clouds: uncertainties caused by sensor, method and atmosphere

    Science.gov (United States)

    Zinner, Tobias; Hausmann, Petra; Ewald, Florian; Bugliaro, Luca; Emde, Claudia; Mayer, Bernhard

    2016-09-01

    In this study a method is introduced for the retrieval of optical thickness and effective particle size of ice clouds over a wide range of optical thickness from ground-based transmitted radiance measurements. Low optical thickness of cirrus clouds and their complex microphysics present a challenge for cloud remote sensing. In transmittance, the relationship between optical depth and radiance is ambiguous. To resolve this ambiguity the retrieval utilizes the spectral slope of radiance between 485 and 560 nm in addition to the commonly employed combination of a visible and a short-wave infrared wavelength.An extensive test of retrieval sensitivity was conducted using synthetic test spectra in which all parameters introducing uncertainty into the retrieval were varied systematically: ice crystal habit and aerosol properties, instrument noise, calibration uncertainty and the interpolation in the lookup table required by the retrieval process. The most important source of errors identified are uncertainties due to habit assumption: Averaged over all test spectra, systematic biases in the effective radius retrieval of several micrometre can arise. The statistical uncertainties of any individual retrieval can easily exceed 10 µm. Optical thickness biases are mostly below 1, while statistical uncertainties are in the range of 1 to 2.5.For demonstration and comparison to satellite data the retrieval is applied to observations by the Munich hyperspectral imager specMACS (spectrometer of the Munich Aerosol and Cloud Scanner) at the Schneefernerhaus observatory (2650 m a.s.l.) during the ACRIDICON-Zugspitze campaign in September and October 2012. Results are compared to MODIS and SEVIRI satellite-based cirrus retrievals (ACRIDICON - Aerosol, Cloud, Precipitation, and Radiation Interactions and Dynamics of Convective Cloud Systems; MODIS - Moderate Resolution Imaging Spectroradiometer; SEVIRI - Spinning Enhanced Visible and Infrared Imager). Considering the identified

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

    Science.gov (United States)

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

    2014-12-01

    Stordalen mire is located at 68°21'N and 19°02'E in the Swedish subarctic. Climate monitoring has revealed a warming trend spanning the past 150 years affecting the mires ability to hold stable palsa/hummock mounds. The micro-topography of the landscape has begun to degrade into thaw ponds changing the vegetation cover from ombrothrophic to minerotrophic. Hummocks are ecologically important due to their ability to act as a carbon sinks. Thaw ponds and sphagnum rich transitional zones have been documented as sources of atmospheric CH4. An objective of this project is to determine if a high resolution three band camera (RGB) and a RGNIR camera could detect differences in vegetation over five different site types. Species composition was collected for 50 plots with ten repetitions for each site type: palsa/hummock, tall shrub, semi-wet, tall graminoid, and wet. Sites were differentiated based on dominating species and features consisting of open water presence, sphagnum spp. cover, graminoid spp. cover, or the presence of dry raised plateaus/mounds. A pole based camera mount was used to collect images at a height of ~2.44m from the ground. The images were cropped in post-processing to fit a one-square meter quadrat. Texture analysis was performed on all images, including entropy, lacunarity, and angular second momentum. Preliminary results suggested that site type influences the number of species present. The p-values for the ability to predict site type using a t-test range from <0.0001 to 0.0461. A stepwise discriminant analysis on site type vs. texture yielded a 10% misclassification rate. Through the use of a stepwise regression of texture variables, actual vs. predicted percent of vegetation coverage provided R squared values of 0.73, 0.71, 0.67, and 0.89 for C. bigelowii, R. chamaemorus, Sphagnum spp., and open water respectively. These data have provided some support to the notion that texture analyses can be used for classification of mire site types. Future

  3. Radioisotope instruments

    CERN Document Server

    Cameron, J F; Silverleaf, D J

    1971-01-01

    International Series of Monographs in Nuclear Energy, Volume 107: Radioisotope Instruments, Part 1 focuses on the design and applications of instruments based on the radiation released by radioactive substances. The book first offers information on the physical basis of radioisotope instruments; technical and economic advantages of radioisotope instruments; and radiation hazard. The manuscript then discusses commercial radioisotope instruments, including radiation sources and detectors, computing and control units, and measuring heads. The text describes the applications of radioisotop

  4. PC based PLCs and ethernet based fieldbus: the new standard platform for future VLT instrument control

    Science.gov (United States)

    Kiekebusch, Mario J.; Lucuix, Christian; Erm, Toomas M.; Chiozzi, Gianluca; Zamparelli, Michele; Kern, Lothar; Brast, Roland; Pirani, Werther; Reiss, Roland; Popovic, Dan; Knudstrup, Jens; Duchateau, Michel; Sandrock, Stefan; Di Lieto, Nicola

    2014-07-01

    ESO is currently in the final phase of the standardization process for PC-based Programmable Logical Controllers (PLCs) as the new platform for the development of control systems for future VLT/VLTI instruments. The standard solution used until now consists of a Local Control Unit (LCU), a VME-based system having a CPU and commercial and proprietary boards. This system includes several layers of software and many thousands of lines of code developed and maintained in house. LCUs have been used for several years as the interface to control instrument functions but now are being replaced by commercial off-the-shelf (COTS) systems based on BECKHOFF Embedded PCs and the EtherCAT fieldbus. ESO is working on the completion of the software framework that enables a seamless integration into the VLT control system in order to be ready to support upcoming instruments like ESPRESSO and ERIS, that will be the first fully VLT compliant instruments using the new standard. The technology evaluation and standardization process has been a long and combined effort of various engineering disciplines like electronics, control and software, working together to define a solution that meets the requirements and minimizes the impact on the observatory operations and maintenance. This paper presents the challenges of the standardization process and the steps involved in such a change. It provides a technical overview of how industrial standards like EtherCAT, OPC-UA, PLCOpen MC and TwinCAT can be used to replace LCU features in various areas like software engineering and programming languages, motion control, time synchronization and astronomical tracking.

  5. On-Board and Ground-Based Complexes for Operating the Science Payload of the CORONAS-F Space Mission

    Science.gov (United States)

    Stepanov, A. I.; Lisin, D. V.; Kuznetsov, V. D.; Afanas'ev, A. N.; Osin, A. I.; Schwarz, J.

    To ensure reliable operation of the science payload of the CORONAS-F satellite and to exercise its flexible control in the course of realization of the research program, an on-board and a specialized ground-based control complexes (GCCs) were designed and manufactured at the Pushkov Institute of Terrestrial Magnetism, Ionosphere, and Radio Wave Propagation (IZMIRAN). A demand for such systems arose because the service facilities of the satellite basic platform were unable to satisfy the requirements of the unique scientific experiments, i.e., an efficient on-line control of the variety of scientific instruments, managing large amounts of scientific information, etc.

  6. Comparison of aerosol optical depths from the Ozone Monitoring Instrument (OMI on Aura with results from airborne sunphotometry, other space and ground measurements during MILAGRO/INTEX-B

    Directory of Open Access Journals (Sweden)

    J. M. Livingston

    2009-04-01

    Full Text Available Airborne sunphotometer measurements are used to evaluate retrievals of extinction aerosol optical depth (AOD from spatially coincident and temporally near-coincident measurements by the Ozone Monitoring Instrument (OMI aboard the Aura satellite during the March 2006 Megacity Initiative-Local And Global Research Observations/Phase B of the Intercontinental Chemical Transport Experiment (MILAGRO/INTEX-B. The 14-channel NASA Ames Airborne Tracking Sunphotometer (AATS flew on nine missions over the Gulf of Mexico and four in or near the Mexico City area. Retrievals of AOD from near-coincident AATS and OMI measurements are compared for three flights over the Gulf of Mexico for flight segments when the aircraft flew at altitudes 60–70 m a.s.l., and for one flight over Mexico City when the aircraft flew ~420–590 m a.g.l. OMI-measured top of atmosphere (TOA reflectances are routinely inverted to yield aerosol products such as AOD and aerosol absorption optical depth (AAOD using two different retrieval algorithms: a near-UV (OMAERUV and a multiwavelength (OMAERO technique. This study uses the archived Collection 3 data products from both algorithms. In particular, AATS and OMI AOD comparisons are presented for AATS data acquired in 20 OMAERUV retrieval pixels (15 over water and 19 OMAERO pixels (also 15 over water. At least four pixels for one of the over-water coincidences and all pixels for the over-land case were cloud-free. Coincident AOD retrievals from 17 pixels of the Moderate Resolution Imaging Spectroradiometer (MODIS aboard Aqua are available for two of the over-water flights and are shown to agree with AATS AODs to within root mean square (RMS differences of 0.00–0.06, depending on wavelength. Near-coincident ground-based AOD measurements from ground-based sun/sky radiometers operated as part of the Aerosol Robotic Network (AERONET at three sites in and near Mexico City are also shown and are generally consistent with the AATS AODs

  7. The Domain Five Observation Instrument: A Competency-Based Coach Evaluation Tool

    Science.gov (United States)

    Shangraw, Rebecca

    2017-01-01

    The Domain Five Observation Instrument (DFOI) is a competency-based observation instrument recommended for sport leaders or researchers who wish to evaluate coaches' instructional behaviors. The DFOI includes 10 behavior categories and four timed categories that encompass 34 observable instructional benchmarks outlined in domain five of the…

  8. A coherency function model of ground motion at base rock corresponding to strike-slip fault

    Institute of Scientific and Technical Information of China (English)

    丁海平; 刘启方; 金星; 袁一凡

    2004-01-01

    At present, the method to study spatial variation of ground motions is statistic analysis based on dense array records such as SMART-1 array, etc. For lacking of information of ground motions, there is no coherency function model of base rock and different style site. Spatial variation of ground motions in elastic media is analyzed by deterministic method in this paper. Taking elastic half-space model with dislocation source of fault, near-field ground motions are simulated. This model takes strike-slip fault and earth media into account. A coherency function is proposed for base rock site.

  9. Optimization of Orchestral Layouts Based on Instrument Directivity Patterns

    Science.gov (United States)

    Stroud, Nathan Paul

    The experience of hearing an exceptional symphony orchestra perform in an excel- lent concert hall can be profound and moving, causing a level of excitement not often reached for listeners. Romantic period style orchestral music, recognized for validating the use of intense emotion for aesthetic pleasure, was the last significant development in the history of the orchestra. In an age where orchestral popularity is waning, the possibil- ity of evolving the orchestral sound in our modern era exists through the combination of our current understanding of instrument directivity patterns and their interaction with architectural acoustics. With the aid of wave field synthesis (WFS), newly proposed variations on orchestral layouts are tested virtually using a 64-channel WFS array. Each layout is objectively and subjectively compared for determination of which layout could optimize the sound of the orchestra and revitalize the excitement of the performance.

  10. An instrumental puzzle: the modular integration of AOLI

    CERN Document Server

    López, Roberto L; Colodro-Conde, Carlos; Valdivia, Juan J F; Puga, Marta; Oscoz, Alejandro; Rebolo, Rafael; Mackay, Craig; Pérez-Garrido, Antonio; Rodríguez-Ramos, Luis Fernando; Rodríguez-Ramos, José M; King, David; Labadie, Lucas; Muthusubramanian, Balaji; Rodríguez-Coira, Gustavo

    2016-01-01

    The Adaptive Optics Lucky Imager, AOLI, is an instrument developed to deliver the highest spatial resolution ever obtained in the visible, 20 mas, from ground-based telescopes. In AOLI a new philosophy of instrumental prototyping has been applied, based on the modularization of the subsystems. This modular concept offers maximum flexibility regarding the instrument, telescope or the addition of future developments.

  11. A ground-based near-infrared emission spectrum of the exoplanet HD 189733b.

    Science.gov (United States)

    Swain, Mark R; Deroo, Pieter; Griffith, Caitlin A; Tinetti, Giovanna; Thatte, Azam; Vasisht, Gautam; Chen, Pin; Bouwman, Jeroen; Crossfield, Ian J; Angerhausen, Daniel; Afonso, Cristina; Henning, Thomas

    2010-02-01

    Detection of molecules using infrared spectroscopy probes the conditions and compositions of exoplanet atmospheres. Water (H(2)O), methane (CH(4)), carbon dioxide (CO(2)), and carbon monoxide (CO) have been detected in two hot Jupiters. These previous results relied on space-based telescopes that do not provide spectroscopic capability in the 2.4-5.2 microm spectral region. Here we report ground-based observations of the dayside emission spectrum for HD 189733b between 2.0-2.4 microm and 3.1-4.1 microm, where we find a bright emission feature. Where overlap with space-based instruments exists, our results are in excellent agreement with previous measurements. A feature at approximately 3.25 microm is unexpected and difficult to explain with models that assume local thermodynamic equilibrium (LTE) conditions at the 1 bar to 1 x 10(-6) bar pressures typically sampled by infrared measurements. The most likely explanation for this feature is that it arises from non-LTE emission from CH(4), similar to what is seen in the atmospheres of planets in our own Solar System. These results suggest that non-LTE effects may need to be considered when interpreting measurements of strongly irradiated exoplanets.

  12. Simulated forecasts for primordial B -mode searches in ground-based experiments

    Science.gov (United States)

    Alonso, David; Dunkley, Joanna; Thorne, Ben; Næss, Sigurd

    2017-02-01

    Detecting the imprint of inflationary gravitational waves on the B -mode polarization of the cosmic microwave background (CMB) is one of the main science cases for current and next-generation CMB experiments. In this work we explore some of the challenges that ground-based facilities will have to face in order to carry out this measurement in the presence of galactic foregrounds and correlated atmospheric noise. We present forecasts for stage-3 (S3) and planned stage-4 (S4) experiments based on the analysis of simulated sky maps using a map-based Bayesian foreground-cleaning method. Our results thus consistently propagate the uncertainties on foreground parameters such as spatially varying spectral indices, as well as the bias on the measured tensor-to-scalar ratio r caused by an incorrect modeling of the foregrounds. We find that S3 and S4-like experiments should be able to put constraints on r of the order σ (r )=(0.5 - 1.0 )×10-2 and σ (r )=(0.5 - 1.0 )×10-3 respectively, assuming instrumental systematic effects are under control. We further study deviations from the fiducial foreground model, finding that, while the effects of a second polarized dust component would be minimal on both S3 and S4, a 2% polarized anomalous dust emission component would be clearly detectable by stage-4 experiments.

  13. A ground-based near-infrared emission spectrum of the exoplanet HD 189733b

    CERN Document Server

    Swain, Mark R; Griffith, Caitlin A; Tinetti, Giovanna; Thatte, Azam; Vasisht, Gautam; Chen, Pin; Bouwman, Jeroen; Crossfield, Ian J; Angerhausen, Daniel; Afonso, Cristina; Henning, Thomas

    2010-01-01

    Detection of molecules using infrared spectroscopy probes the conditions and compositions of exoplanet atmospheres. Water (H2O), methane (CH4), carbon dioxide (CO2), and carbon monoxide (CO) have been detected in two hot Jupiters. These previous results relied on space-based telescopes that do not provide spectroscopic capability in the 2.4 - 5.2 micron spectral region. Here we report ground-based observations of the dayside emission spectrum for HD 189733b between 2.0-2.4 micron and 3.1-4.1 micron, where we find a bright emission feature. Where overlap with space-based instruments exists, our results are in excellent agreement with previous measurements. A feature at ~3.25 micron is unexpected and difficult to explain with models that assume local thermodynamic equilibrium (LTE) conditions at the 1 bar to 1 x 10-6 bar pressures typically sampled by infrared measurements. The most likely explanation for this feature is that it arises from non-LTE emission from CH4, similar to what is seen in the atmospheres o...

  14. TEMIS UV product validation using NILU-UV ground-based measurements in Thessaloniki, Greece

    Science.gov (United States)

    Zempila, Melina-Maria; van Geffen, Jos H. G. M.; Taylor, Michael; Fountoulakis, Ilias; Koukouli, Maria-Elissavet; van Weele, Michiel; van der A, Ronald J.; Bais, Alkiviadis; Meleti, Charikleia; Balis, Dimitrios

    2017-06-01

    This study aims to cross-validate ground-based and satellite-based models of three photobiological UV effective dose products: the Commission Internationale de l'Éclairage (CIE) erythemal UV, the production of vitamin D in the skin, and DNA damage, using high-temporal-resolution surface-based measurements of solar UV spectral irradiances from a synergy of instruments and models. The satellite-based Tropospheric Emission Monitoring Internet Service (TEMIS; version 1.4) UV daily dose data products were evaluated over the period 2009 to 2014 with ground-based data from a Norsk Institutt for Luftforskning (NILU)-UV multifilter radiometer located at the northern midlatitude super-site of the Laboratory of Atmospheric Physics, Aristotle University of Thessaloniki (LAP/AUTh), in Greece. For the NILU-UV effective dose rates retrieval algorithm, a neural network (NN) was trained to learn the nonlinear functional relation between NILU-UV irradiances and collocated Brewer-based photobiological effective dose products. Then the algorithm was subjected to sensitivity analysis and validation. The correlation of the NN estimates with target outputs was high (r = 0. 988 to 0.990) and with a very low bias (0.000 to 0.011 in absolute units) proving the robustness of the NN algorithm. For further evaluation of the NILU NN-derived products, retrievals of the vitamin D and DNA-damage effective doses from a collocated Yankee Environmental Systems (YES) UVB-1 pyranometer were used. For cloud-free days, differences in the derived UV doses are better than 2 % for all UV dose products, revealing the reference quality of the ground-based UV doses at Thessaloniki from the NILU-UV NN retrievals. The TEMIS UV doses used in this study are derived from ozone measurements by the SCIAMACHY/Envisat and GOME2/MetOp-A satellite instruments, over the European domain in combination with SEVIRI/Meteosat-based diurnal cycle of the cloud cover fraction per 0. 5° × 0. 5° (lat × long) grid cells. TEMIS

  15. Cosmic ray measurements in the knee region: new perspectives for simultaneous air-borne and ground-based observations

    Energy Technology Data Exchange (ETDEWEB)

    Marrocchesi, P.S. [Physics Dept., Univ. of Siena and INFN, 56 via Roma, 53100 Siena (Italy)]. E-mail: marrocchesi@pi.infn.it

    2006-01-15

    Direct measurements of cosmic ray composition and energy spectra in the knee region (10{sup 15} to 10{sup 16} eV) represent a real challenge for balloon and space borne experiments due to their limited exposure. On the other hand, ground-based extensive air shower arrays (EAS) can provide a measurement of the primary particle energy but fail to identify unambiguously its nature. The possibility to couple a large area instrument in flight, dedicated to the charge identification of the primary nucleus, with a ground array is explored. This task is within the reach of today detector technologies but requires a formidable step in the current development of stratospheric airship platforms capable of maintaining a long-duration stationary position above the EAS array.

  16. Ground-based & satellite DOAS measurements integration for air quality evaluation/forecast management in the frame of QUITSAT Project.

    Science.gov (United States)

    Kostadinov, Ivan; Petritoli, Andrea; Giovanelli, Giorgio; Masieri, Samuele; Premuda, Margarita; Bortoli, Daniele; Ravegnani, Fabrizio; Palazzi, Elisa

    The observations of the Earth's atmosphere from space provide excellent opportunities for the exploration of the sophisticated physical-chemical processes on both global and regional scales. The major interest during the last three decades was focused mainly on the stratosphere and the ozone depletion. More recently the continuous improvements of satellite sensors have revealed new opportunities for larger applications of space observations, attracting scientific interest to the lower troposphere and air quality issues. The air quality depends strongly on the anthropogenic activity and therefore regional environmental agencies along with policy makers are in need of appropriate means for its continuous monitoring and control to ensure the adoption of the most appropriate actions. The goal of the pilot project QUITSAT, funded by the Italian Space Agency, is to develop algorithms and procedures for the evaluation and prediction of the air quality in Lombardia and Emilia-Romagna regions (Italy) by means of integrating satellite observations with ground-based in-situ and remote sensing measurements. This work presents dedicated Differential Optical Absorption Spectroscopy (DOAS) measurements performed during the summer of 2007 and the winter of 2008. One of the DOAS instruments operate at Mt.Cimone station (2165m a.s.l) and the other two instruments conducted measurements in/near Bologna (90 m. a.s.l). Different observational geometry was adopted (zenith-sky, multi-axis and long-path) aimed to provide tropospheric NO2 columns and O3, SO2 and HCHO concentrations at ground level as an input data for QUITSAT procedures. Details of the instruments, the radiative transfer model used and the algorithms for retrieving and calculation of the target gases concentrations are presented. The obtained experimental results are correlated with the corresponding ones retrieved from SCIAMACHY /ENVISAT observations during the overpasses above the ground-based instruments. The analysis

  17. An instrument for the assessment of diarrhoeal severity based on a longitudinal community-based study

    Science.gov (United States)

    Lee, Gwenyth; Peñataro Yori, Pablo; Paredes Olortegui, Maribel; Caulfield, Laura E; Sack, David A; Fischer-Walker, Christa; Black, Robert E; Kosek, Margaret

    2014-01-01

    Objective Diarrhoea is a significant contributer to morbidity and is among the leading causes of death of children living in poverty. As such, the incidence, duration and severity of diarrhoeal episodes in the household are often key variables of interest in a variety of community-based studies. However, there currently exists no means of defining diarrhoeal severity that are (A) specifically designed and adapted for community-based studies, (B) associated with poorer child outcomes and (C) agreed on by the majority of researchers. Clinical severity scores do exist and are used in healthcare settings, but these tend to focus on relatively moderate-to-severe dehydrating and dysenteric disease, require trained observation of the child and, given the variability of access and utilisation of healthcare, fail to sufficiently describe the spectrum of disease in the community setting. Design Longitudinal cohort study. Setting Santa Clara de Nanay, a rural community in the Northern Peruvian Amazon. Participants 442 infants and children 0–72 months of age. Main outcome measures Change in weight over 1-month intervals and change in length/height over 9-month intervals. Results Diarrhoeal episodes with symptoms of fever, anorexia, vomiting, greater number of liquid stools per day and greater number of total stools per day were associated with poorer weight gain compared with episodes without these symptoms. An instrument to measure the severity was constructed based on the duration of these symptoms over the course of a diarrhoeal episode. Conclusions In order to address limitations of existing diarrhoeal severity scores in the context of community-based studies, we propose an instrument comprised of diarrhoea-associated symptoms easily measured by community health workers and based on the association of these symptoms with poorer child growth. This instrument can be used to test the impact of interventions on the burden of diarrhoeal disease. PMID:24907244

  18. Scaling earthquake ground motions for performance-based assessment of buildings

    Science.gov (United States)

    Huang, Y.-N.; Whittaker, A.S.; Luco, N.; Hamburger, R.O.

    2011-01-01

    The impact of alternate ground-motion scaling procedures on the distribution of displacement responses in simplified structural systems is investigated. Recommendations are provided for selecting and scaling ground motions for performance-based assessment of buildings. Four scaling methods are studied, namely, (1)geometric-mean scaling of pairs of ground motions, (2)spectrum matching of ground motions, (3)first-mode-period scaling to a target spectral acceleration, and (4)scaling of ground motions per the distribution of spectral demands. Data were developed by nonlinear response-history analysis of a large family of nonlinear single degree-of-freedom (SDOF) oscillators that could represent fixed-base and base-isolated structures. The advantages and disadvantages of each scaling method are discussed. The relationship between spectral shape and a ground-motion randomness parameter, is presented. A scaling procedure that explicitly considers spectral shape is proposed. ?? 2011 American Society of Civil Engineers.

  19. Observation of TGFs onboard "Vernov" satellite and TGEs in ground-based experiments

    Science.gov (United States)

    Bogomolov, Vitaly; Panasyuk, Mikhail; Svertilov, Sergey; Garipov, Gali; Iyudin, Anatoly; Klimov, Pavel; Morozenko, Violetta; Maximov, Ivan; Mishieva, Tatiana; Klimov, Stanislav; Pozanenko, Alexey; Rothkaehl, Hanna

    2016-04-01

    "Vernov" satellite with RELEC experiment on-board was launched on 2014 July, 8 into a polar solar-synchronous orbit. The payload includes DRGE gamma-ray spectrometer providing measurements in 10-3000 keV energy range with four detectors directed to atmosphere. Total area of DRGE detectors is ~500 cm2. The data were recorded both in monitoring and gamma by gamma modes with timing accuracy ~15 us. Several TGF candidates with 10-40 gammas in a burst with duration instruments on-board "Vernov" satellite shows the absence of significant electromagnetic pulses around correspondent time moments. Comparison with WWLLN lightning network data base also indicates that there were no thunderstorms connected with most of detected TGF candidates. Possible connection of these flashes with electron precipitations is discussed. Ground-based experiments, with similar gamma-spectrometers were conducted, to study the spectral, temporal and spatial characteristics of TGEs in 20-3000 keV energy range, as well, as to search the fast hard X-ray and gamma-ray flashes possibly appearing at the moment of lightning. The time of each gamma-quantum interaction was recorded with an ~15 us s accuracy together with detailed spectral data. Measurements were done on the ground at Moscow region, and at mountain altitude in Armenia at Aragatz station. During the time interval covering spring, summer and autumn of 2015 a number of TGEs were detected. Measured low-energy gamma-ray spectra usually contain a set of lines that can be interpreted as radiation of Rn-222 daughter isotopes. The increase of Rn-222 radiation was detected during rainfalls with thunderstorm, as well, as during rainy weather without thunderstorms. Variations of Rn-222 radiation dominate at low energies (measure low energy gamma-radiation from the electrons accelerated in thunderclouds. There were no significant flashes with duration of ~1ms detected in coincidence with a nearby lightnings.

  20. Microwave signatures of ice hydrometeors from ground-based observations above Summit, Greenland

    Directory of Open Access Journals (Sweden)

    C. Pettersen

    2015-12-01

    Full Text Available Multi-instrument, ground-based measurements provide unique and comprehensive datasets of the atmosphere for a specific location over long periods of time and resulting data compliments past and existing global satellite observations. This paper explores the effect of ice hydrometeors on ground-based, high frequency passive microwave measurements and attempts to isolate an ice signature for summer seasons at Summit, Greenland from 2010–2013. Data from a combination of passive microwave, cloud radar, radiosonde, and ceilometer were examined to isolate the ice signature at microwave wavelengths. By limiting the study to a cloud liquid water path of 40 g m−2 or less, the cloud radar can identify cases where the precipitation was dominated by ice. These cases were examined using liquid water and gas microwave absorption models, and brightness temperatures were calculated for the high frequency microwave channels: 90, 150, and 225 GHz. By comparing the measured brightness temperatures from the microwave radiometers and the calculated brightness temperature using only gas and liquid contributions, any residual brightness temperature difference is due to emission and scattering of microwave radiation from the ice hydrometeors in the column. The ice signature in the 90, 150, and 225 GHz channels for the Summit Station summer months was isolated. This measured ice signature was then compared to an equivalent brightness temperature difference calculated with a radiative transfer model including microwave single scattering properties for several ice habits. Initial model results compare well against the four years of summer season isolated ice signature in the high-frequency microwave channels.

  1. Design concepts for the Cherenkov Telescope Array CTA: an advanced facility for ground-based high-energy gamma-ray astronomy

    OpenAIRE

    Actis, M.; Agnetta, G.; Aharonian, F.; Akhperjanian, A.; Aleksić, J.; Aliu, E.; Allan, D.; Allekotte, I.; Antico, F.; Antonelli, L.A.; Antoranz, P.; Aravantinos, A.; Arlen, T.; Arnaldi, H.; Artmann, S

    2011-01-01

    Ground-based gamma-ray astronomy has had a major breakthrough with the impressive results obtained using systems of imaging atmospheric Cherenkov telescopes. Ground-based gamma-ray astronomy has a huge potential in astrophysics, particle physics and cosmology. CTA is an international initiative to build the next generation instrument, with a factor of 5-10 improvement in sensitivity in the 100 GeV to 10 TeV range and the extension to energies well below 100 GeV and above 100 TeV. CTA will con...

  2. Ground-based gamma-ray telescopes as ground stations in deep-space lasercom

    CERN Document Server

    Carrasco-Casado, Alberto; Vergaz, Ricardo

    2016-01-01

    As the amount of information to be transmitted from deep-space rapidly increases, the radiofrequency technology has become a bottleneck in space communications. RF is already limiting the scientific outcome of deep-space missions and could be a significant obstacle in the developing of manned missions. Lasercom holds the promise to solve this problem, as it will considerably increase the data rate while decreasing the energy, mass and volume of onboard communication systems. In RF deep-space communications, where the received power is the main limitation, the traditional approach to boost the data throughput has been increasing the receiver's aperture, e.g. the 70-m antennas in the NASA's Deep Space Network. Optical communications also can benefit from this strategy, thus 10-m class telescopes have typically been suggested to support future deep-space links. However, the cost of big telescopes increase exponentially with their aperture, and new ideas are needed to optimize this ratio. Here, the use of ground-...

  3. The COnsensus-based Standards for the selection of health Measurement INstruments (COSMIN and how to select an outcome measurement instrument

    Directory of Open Access Journals (Sweden)

    Lidwine B. Mokkink

    2016-01-01

    Full Text Available Background: COSMIN (COnsensus-based Standards for the selection of health Measurement INstruments is an initiative of an international multidisciplinary team of researchers who aim to improve the selection of outcome measurement instruments both in research and in clinical practice by developing tools for selecting the most appropriate available instrument. Method: In this paper these tools are described, i.e. the COSMIN taxonomy and definition of measurement properties; the COSMIN checklist to evaluate the methodological quality of studies on measurement properties; a search filter for finding studies on measurement properties; a protocol for systematic reviews of outcome measurement instruments; a database of systematic reviews of outcome measurement instruments; and a guideline for selecting outcome measurement instruments for Core Outcome Sets in clinical trials. Currently, we are updating the COSMIN checklist, particularly the standards for content validity studies. Also new standards for studies using Item Response Theory methods will be developed. Additionally, in the future we want to develop standards for studies on the quality of non-patient reported outcome measures, such as clinician-reported outcomes and performance-based outcomes. Conclusions: In summary, we plea for more standardization in the use of outcome measurement instruments, for conducting high quality systematic reviews on measurement instruments in which the best available outcome measurement instrument is recommended, and for stopping the use of poor outcome measurement instruments.

  4. Ground-Based Observing Campaign of Briz-M Debris

    Science.gov (United States)

    Lederer, S. M.; Buckalew, B.; Frith, J.; Cowardin, H. M.; Hickson, P.; Matney, M.; Anz-Meador, P.

    2017-01-01

    In 2015, NASA's Orbital Debris Program Office (ODPO) completed the installation of the Meter Class Autonomous Telescope (MCAT) on Ascension Island. MCAT is a 1.3m optical telescope designed with a fast tracking capability for observing orbital debris at all orbital regimes (Low-Erath orbits to Geosyncronous (GEO) orbits) from a low latitude site. This new asset is dedicated year-round for debris observations, and its location fills a geographical gap in the Ground-based Electro Optical Space Surveillance (GEODSS) network. A commercial off the shelf (COTS) research grade 0.4m telescope (named the Benbrook telescope) will also be installed on Ascension at the end of 2016. This smaller version is controlled by the same master software, designed by Euclid Research, and can be tasked to work independently or in concert with MCAT. Like MCAT, it has a the same suite of filters, a similar field of view, and a fast-tracking Astelco mount, and is also capable of tracking debris at all orbital regimes. These assets are well suited for targeted campagins or surveys of debris. Since 2013, NASA's ODPO has also had extensive access to the 3.8m infrared UKIRT telescope, located on Mauna Kea. At nearly 14,000-ft, this site affords excellent conditions for collecting both photometery and spectroscopy at near-IR (0.9 - 2.5 micrometers SWIR) and thermal-IR (8 - 25 micrometers; LWIR) regimes, ideal for investigating material properties as well as thermal characteristics and sizes of debris. For the purposes of understanding orbital debris, taking data in both survey mode as well as targeting individual objects for more in-depth characterizations are desired. With the recent break-ups of Briz-M rocket bodies, we have collected a suite of data in the optical, near-infrared, and mid-infrared of in-tact objects as well as those classified as debris. A break-up at GEO of a Briz-M rocket occurred in January, 2016, well timed for the first remote observing survey-campaign with MCAT. Access to

  5. Overview and Initial Results from the DEEPWAVE Airborne and Ground-Based Measurement Program

    Science.gov (United States)

    Fritts, D. C.

    2015-12-01

    The deep-propagating gravity wave experiment (DEEPWAVE) was performed on and over New Zealand, the Tasman Sea, and the Southern Ocean with core airborne measurements extending from 5 June to 21 July 2014 and supporting ground-based measurements spanning a longer interval. The NSF/NCAR GV employed standard flight-level measurements and new airborne lidar and imaging measurements of gravity waves (GWs) from sources at lower altitudes throughout the stratosphere and into the mesosphere and lower thermosphere (MLT). The new GV lidars included a Rayleigh lidar measuring atmospheric density and temperature from ~20-60 km and a sodium resonance lidar measuring sodium density and temperature at ~75-105 km. An airborne Advanced Mesosphere Temperature Mapper (AMTM) and two IR "wing" cameras imaged the OH airglow temperature and/or intensity fields extending ~900 km across the GV flight track. The DLR Falcon was equipped with its standard flight-level instruments and an aerosol Doppler lidar measuring radial winds below the Falcon. DEEPWAVE also included extensive ground-based measurements in New Zealand, Tasmania, and Southern Ocean Islands. DEEPWAVE performed 26 GV flights and 13 Falcon flights, and ground-based measurements occurred whether or not the aircraft were flying. Collectively, many diverse cases of GW forcing, propagation, refraction, and dissipation spanning altitudes of 0-100 km were observed. Examples include strong mountain wave (MW) forcing and breaking in the lower and middle stratosphere, weak MW forcing yielding MW penetration into the MLT having very large amplitudes and momentum fluxes, MW scales at higher altitudes ranging from ~10-250 km, large-scale trailing waves from orography refracting into the polar vortex and extending to high altitudes, GW generation by deep convection, large-scale GWs arising from jet stream sources, and strong MWs in the MLT arising from strong surface flow over a small island. DEEPWAVE yielded a number of surprises, among

  6. Planetary Protection Plan for an Antibody based instrument proposed for Mars2020

    Science.gov (United States)

    Smith, Heather; Parro, Víctor

    The Signs Of Life Detector (SOLID) instrument is a high TRL level instrument proposed for the Mars 2020 instrument suite. In this presentation we describe the planetary protection instrument plan as if the instrument is classified as a life detection instrument compliant with Category IV(b) planetary protection mission requirements, NASA, ESA, and COSPAR policy. SOLID uses antibodies as a method for detecting organic and biomolecular components in soils. Due to the sensitive detection method, the scientific integrity of the instrument exceeds the planetary protection requirements. The instrument will be assembled and integrated in an ISO level 8 cleanroom or better (ISO 4 for the sample read out and fluidics components). Microbial reduction methods and assays employed are as follows: Wipe the outside and inside of the instrument with a mixture of isopropyl alcohol (70%) and water. Cell cultures will be the standard assay to determine enumeration of “viable” spores and other rapid assays such as LAL and ATP bioluminescence as secondary assays to verify the interior of the instrument is microbe free. SOLID’s design factors for contamination control include the following features: SOLID has the capability to heat the catchment tray to pyrolyze any Earth hitchhikers. There will also be an “air gap” of cm maintained between the sample acquisition device and the funnel inlet. This will prevent forward contamination of the sample collection device and reverse contamination of the detection unit. To mitigate false positives, SOLID will include anti-bodies for potential contaminants from organisms most commonly found in clean rooms. If selected for the Mars 2020 Rover, SOLID would be the first life detection instrument based on biomolecules sent by NASA, as such the planetary protection plan will set a precedence for future life detection instruments carrying biomolecules to other planetary bodies.

  7. Development of Novel, Optically-Based Instrumentation for Aircraft System Testing and Control Project

    Data.gov (United States)

    National Aeronautics and Space Administration — We propose to develop a compact, robust, optically-based sensor for making temperature and multi-species concentration measurements in aircraft system ground and...

  8. Seismic Responses of Asymmetric Base-Isolated Structures under Near-Fault Ground Motion

    Institute of Scientific and Technical Information of China (English)

    YE Kun; LI Li; FANG Qin-han

    2008-01-01

    An inter-story shear model of asymmetric base-isolated structures incorporating deformation of each isolation bearing was built, and a method to simultaneously simulate bi-directional near-fault and far-field ground motions was proposed. A comparative study on the dynamic responses of asymmetric base-isolated structures under near-fault and far-field ground motions were conducted to investigate the effects of eccentricity in the isolation system and in the superstructures, the ratio of the uncoupled torsional to lateral frequency of the superstructure and the pulse period of near-fault ground motions on the nonlinear seismic response of asymmetric base-isolated structures. Numerical results show that eccentricity in the isolation system makes asymmetric base-isolated structure more sensitive to near-fault ground motions, and the pulse period of near-fault ground motions plays an import role in governing the seismic responses of asymmetric base-isolated structures.

  9. Secure Web-based Ground System User Interfaces over the Open Internet

    Science.gov (United States)

    Langston, James H.; Murray, Henry L.; Hunt, Gary R.

    1998-01-01

    A prototype has been developed which makes use of commercially available products in conjunction with the Java programming language to provide a secure user interface for command and control over the open Internet. This paper reports successful demonstration of: (1) Security over the Internet, including encryption and certification; (2) Integration of Java applets with a COTS command and control product; (3) Remote spacecraft commanding using the Internet. The Java-based Spacecraft Web Interface to Telemetry and Command Handling (Jswitch) ground system prototype provides these capabilities. This activity demonstrates the use and integration of current technologies to enable a spacecraft engineer or flight operator to monitor and control a spacecraft from a user interface communicating over the open Internet using standard World Wide Web (WWW) protocols and commercial off-the-shelf (COTS) products. The core command and control functions are provided by the COTS Epoch 2000 product. The standard WWW tools and browsers are used in conjunction with the Java programming technology. Security is provided with the current encryption and certification technology. This system prototype is a step in the direction of giving scientist and flight operators Web-based access to instrument, payload, and spacecraft data.

  10. Characterization of absorbing aerosol types using ground and satellites based observations over an urban environment

    Science.gov (United States)

    Bibi, Samina; Alam, Khan; Chishtie, Farrukh; Bibi, Humera

    2017-02-01

    In this paper, for the first time, an effort has been made to seasonally characterize the absorbing aerosols into different types using ground and satellite based observations. For this purpose, optical properties of aerosol retrieved from AErosol RObotic NETwork (AERONET) and Ozone Monitoring Instrument (OMI) were utilized over Karachi for the period 2012 to 2014. Firstly, OMI AODabs was validated with AERONET AODabs and found to have a high degree of correlation. Then, based on this validation, characterization was conducted by analyzing aerosol Fine Mode Fraction (FMF), Angstrom Exponent (AE), Absorption Angstrom Exponent (AAE), Single Scattering Albedo (SSA) and Aerosol Index (AI) and their mutual correlation, to identify the absorbing aerosol types and also to examine the variability in seasonal distribution. The absorbing aerosols were characterized into Mostly Black Carbon (BC), Mostly Dust and Mixed BC & Dust. The results revealed that Mostly BC aerosols contributed dominantly during winter and postmonsoon whereas, Mostly Dust were dominant during summer and premonsoon. These types of absorbing aerosol were also confirmed with MODerate resolution Imaging Spectroradiometer (MODIS) and Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation (CALIPSO) observations.

  11. Ground-based remote sensing scheme for monitoring aerosol–cloud interactions

    Directory of Open Access Journals (Sweden)

    K. Sarna

    2015-11-01

    Full Text Available A method for continuous observation of aerosol–cloud interactions with ground-based remote sensing instruments is presented. The main goal of this method is to enable the monitoring of cloud microphysical changes due to the changing aerosol concentration. We use high resolution measurements from lidar, radar and radiometer which allow to collect and compare data continuously. This method is based on a standardised data format from Cloudnet and can be implemented at any observatory where the Cloudnet data set is available. Two example study cases were chosen from the Atmospheric Radiation Measurement (ARM Program deployment at Graciosa Island, Azores, Portugal in 2009 to present the method. We show the Pearson Product–Moment Correlation Coefficient, r, and the Coefficient of Determination, r2 for data divided into bins of LWP, each of 10 g m−2. We explain why the commonly used way of quantity aerosol cloud interactions by use of an ACI index (ACIr,τ = dln re,τ/dlnα is not the best way of quantifying aerosol–cloud interactions.

  12. Secure Web-based Ground System User Interfaces over the Open Internet

    Science.gov (United States)

    Langston, James H.; Murray, Henry L.; Hunt, Gary R.

    1998-01-01

    A prototype has been developed which makes use of commercially available products in conjunction with the Java programming language to provide a secure user interface for command and control over the open Internet. This paper reports successful demonstration of: (1) Security over the Internet, including encryption and certification; (2) Integration of Java applets with a COTS command and control product; (3) Remote spacecraft commanding using the Internet. The Java-based Spacecraft Web Interface to Telemetry and Command Handling (Jswitch) ground system prototype provides these capabilities. This activity demonstrates the use and integration of current technologies to enable a spacecraft engineer or flight operator to monitor and control a spacecraft from a user interface communicating over the open Internet using standard World Wide Web (WWW) protocols and commercial off-the-shelf (COTS) products. The core command and control functions are provided by the COTS Epoch 2000 product. The standard WWW tools and browsers are used in conjunction with the Java programming technology. Security is provided with the current encryption and certification technology. This system prototype is a step in the direction of giving scientist and flight operators Web-based access to instrument, payload, and spacecraft data.

  13. Developing evaluation instrument based on CIPP models on the implementation of portfolio assessment

    Science.gov (United States)

    Kurnia, Feni; Rosana, Dadan; Supahar

    2017-08-01

    This study aimed to develop an evaluation instrument constructed by CIPP model on the implementation of portfolio assessment in science learning. This study used research and development (R & D) method; adapting 4-D by the development of non-test instrument, and the evaluation instrument constructed by CIPP model. CIPP is the abbreviation of Context, Input, Process, and Product. The techniques of data collection were interviews, questionnaires, and observations. Data collection instruments were: 1) the interview guidelines for the analysis of the problems and the needs, 2) questionnaire to see level of accomplishment of portfolio assessment instrument, and 3) observation sheets for teacher and student to dig up responses to the portfolio assessment instrument. The data obtained was quantitative data obtained from several validators. The validators consist of two lecturers as the evaluation experts, two practitioners (science teachers), and three colleagues. This paper shows the results of content validity obtained from the validators and the analysis result of the data obtained by using Aikens' V formula. The results of this study shows that the evaluation instrument based on CIPP models is proper to evaluate the implementation of portfolio assessment instruments. Based on the experts' judgments, practitioners, and colleagues, the Aikens' V coefficient was between 0.86-1,00 which means that it is valid and can be used in the limited trial and operational field trial.

  14. Arduino-based laboratory instruments for an undergraduate laser cooling experiment

    Science.gov (United States)

    Ireland, Timothy; Tiber, Gage; Brooke, Robert W. A.; Gillis, Julie M.; Zaccagnini, Christopher A.; Corcovilos, Theodore A.

    2015-05-01

    Arduino is an inexpensive open-source microcontroller platform designed for quick development turn-around and easy interfacing, making it ideal for novice programmers and instrument designers. Based on Atmel ATMEGA microcontroller chips, the Arduino boards are programmed with standard C/C++ code and contain sufficient inputs and outputs (both digital and analog) for basic data acquisition and device control. Here we present home-built Arduino-based instruments commonly used in laser-cooling experiments, such as a wavelength meter and temperature controller. We describe the design and performance of these instruments.

  15. Analyses of Cryogenic Propellant Tank Pressurization based upon Ground Experiments

    OpenAIRE

    Ludwig, Carina; Dreyer, Michael

    2012-01-01

    The pressurization system of cryogenic propellant rockets requires on-board pressurant gas. The objective of this study was to analyze the influence of the pressurant gas temperature on the required pressurant gas mass in terms of lowering the launcher mass. First, ground experiments were performed in order to investigate the pressurization process with regard to the influence of the pressurant gas inlet temperature. Second, a system study for the cryogenic upper stage of a sma...

  16. Validation of MOPITT carbon monoxide using ground-based Fourier transform infrared spectrometer data from NDACC

    Science.gov (United States)

    Buchholz, Rebecca R.; Deeter, Merritt N.; Worden, Helen M.; Gille, John; Edwards, David P.; Hannigan, James W.; Jones, Nicholas B.; Paton-Walsh, Clare; Griffith, David W. T.; Smale, Dan; Robinson, John; Strong, Kimberly; Conway, Stephanie; Sussmann, Ralf; Hase, Frank; Blumenstock, Thomas; Mahieu, Emmanuel; Langerock, Bavo

    2017-06-01

    The Measurements of Pollution in the Troposphere (MOPITT) satellite instrument provides the longest continuous dataset of carbon monoxide (CO) from space. We perform the first validation of MOPITT version 6 retrievals using total column CO measurements from ground-based remote-sensing Fourier transform infrared spectrometers (FTSs). Validation uses data recorded at 14 stations, that span a wide range of latitudes (80° N to 78° S), in the Network for the Detection of Atmospheric Composition Change (NDACC). MOPITT measurements are spatially co-located with each station, and different vertical sensitivities between instruments are accounted for by using MOPITT averaging kernels (AKs). All three MOPITT retrieval types are analyzed: thermal infrared (TIR-only), joint thermal and near infrared (TIR-NIR), and near infrared (NIR-only). Generally, MOPITT measurements overestimate CO relative to FTS measurements, but the bias is typically less than 10 %. Mean bias is 2.4 % for TIR-only, 5.1 % for TIR-NIR, and 6.5 % for NIR-only. The TIR-NIR and NIR-only products consistently produce a larger bias and lower correlation than the TIR-only. Validation performance of MOPITT for TIR-only and TIR-NIR retrievals over land or water scenes is equivalent. The four MOPITT detector element pixels are validated separately to account for their different uncertainty characteristics. Pixel 1 produces the highest standard deviation and lowest correlation for all three MOPITT products. However, for TIR-only and TIR-NIR, the error-weighted average that includes all four pixels often provides the best correlation, indicating compensating pixel biases and well-captured error characteristics. We find that MOPITT bias does not depend on latitude but rather is influenced by the proximity to rapidly changing atmospheric CO. MOPITT bias drift has been bound geographically to within ±0.5 % yr-1 or lower at almost all locations.

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

    Directory of Open Access Journals (Sweden)

    M. Haeffelin

    2005-02-01

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

  18. Tentative detection of clear-air turbulence using a ground-based Rayleigh lidar.

    Science.gov (United States)

    Hauchecorne, Alain; Cot, Charles; Dalaudier, Francis; Porteneuve, Jacques; Gaudo, Thierry; Wilson, Richard; Cénac, Claire; Laqui, Christian; Keckhut, Philippe; Perrin, Jean-Marie; Dolfi, Agnès; Cézard, Nicolas; Lombard, Laurent; Besson, Claudine

    2016-05-01

    Atmospheric gravity waves and turbulence generate small-scale fluctuations of wind, pressure, density, and temperature in the atmosphere. These fluctuations represent a real hazard for commercial aircraft and are known by the generic name of clear-air turbulence (CAT). Numerical weather prediction models do not resolve CAT and therefore provide only a probability of occurrence. A ground-based Rayleigh lidar was designed and implemented to remotely detect and characterize the atmospheric variability induced by turbulence in vertical scales between 40 m and a few hundred meters. Field measurements were performed at Observatoire de Haute-Provence (OHP, France) on 8 December 2008 and 23 June 2009. The estimate of the mean squared amplitude of bidimensional fluctuations of lidar signal showed excess compared to the estimated contribution of the instrumental noise. This excess can be attributed to atmospheric turbulence with a 95% confidence level. During the first night, data from collocated stratosphere-troposphere (ST) radar were available. Altitudes of the turbulent layers detected by the lidar were roughly consistent with those of layers with enhanced radar echo. The derived values of turbulence parameters Cn2 or CT2 were in the range of those published in the literature using ST radar data. However, the detection was at the limit of the instrumental noise and additional measurement campaigns are highly desirable to confirm these initial results. This is to our knowledge the first successful attempt to detect CAT in the free troposphere using an incoherent Rayleigh lidar system. The built lidar device may serve as a test bed for the definition of embarked CAT detection lidar systems aboard airliners.

  19. Radiometric modeling and calibration of the Geostationary Imaging Fourier Transform Spectrometer (GIFTS) ground based measurement experiment

    Science.gov (United States)

    Tian, Jialin; Smith, William L.; Gazarik, Michael J.

    2008-12-01

    The ultimate remote sensing benefits of the high resolution Infrared radiance spectrometers will be realized with their geostationary satellite implementation in the form of imaging spectrometers. This will enable dynamic features of the atmosphere's thermodynamic fields and pollutant and greenhouse gas constituents to be observed for revolutionary improvements in weather forecasts and more accurate air quality and climate predictions. As an important step toward realizing this application objective, the Geostationary Imaging Fourier Transform Spectrometer (GIFTS) Engineering Demonstration Unit (EDU) was successfully developed under the NASA New Millennium Program, 2000-2006. The GIFTS-EDU instrument employs three focal plane arrays (FPAs), which gather measurements across the long-wave IR (LWIR), short/mid-wave IR (SMWIR), and visible spectral bands. The GIFTS calibration is achieved using internal blackbody calibration references at ambient (260 K) and hot (286 K) temperatures. In this paper, we introduce a refined calibration technique that utilizes Principle Component (PC) analysis to compensate for instrument distortions and artifacts, therefore, enhancing the absolute calibration accuracy. This method is applied to data collected during the GIFTS Ground Based Measurement (GBM) experiment, together with simultaneous observations by the accurately calibrated AERI (Atmospheric Emitted Radiance Interferometer), both simultaneously zenith viewing the sky through the same external scene mirror at ten-minute intervals throughout a cloudless day at Logan Utah on September 13, 2006. The accurately calibrated GIFTS radiances are produced using the first four PC scores in the GIFTS-AERI regression model. Temperature and moisture profiles retrieved from the PC-calibrated GIFTS radiances are verified against radiosonde measurements collected throughout the GIFTS sky measurement period. Using the GIFTS GBM calibration model, we compute the calibrated radiances from data

  20. A study of remotely sensed aerosol properties from ground-based sun and sky scanning radiometers

    Science.gov (United States)

    Giles, David M.

    . The sensitivity of absorption properties is evaluated and quantified with respect to aerosol retrieval uncertainty. Using clustering analysis, aerosol absorption and size relationships provide a simple method to classify aerosol mixing states and origins and potentially improve aerosol retrievals from ground-based and satellite-based instrumentation.

  1. Exploratory and Creative Properties of Physical-Modeling-based Musical Instruments

    DEFF Research Database (Denmark)

    Gelineck, Steven

    modeling. I investigate how various control elements such as explorability, mapping, intuitiveness, perceived causality, physicality, unpre- dictability, accuracy, connectivity, freedom and constraints can affect the overall cre- ative potential of a physical modeling based musical instrument. Initially......Digital musical instruments are developed to enable musicians to find new ways of expressing themselves. The development and evaluation of these instruments can be approached from many different perspectives depending on which capabilities one wants the musicians to have. This thesis attempts...... to approach development and evaluation of these instruments with the notion that instruments today are able to facilitate the creative process that is so crucial for creating music. The fundamental question pursued throughout the thesis is how creative work processes of composers of electronic music can...

  2. Comparison of total ozone and erythemal UV data from OMI with ground-based measurements at Rome station

    Directory of Open Access Journals (Sweden)

    I. Ialongo

    2008-02-01

    Full Text Available Ground-based total ozone and surface UV irradiance measurements have been collected since 1992 using Brewer spectrophotometer and Erythemal Dose Rates (EDRs have been determined by a broad-band radiometer (model YES UVB-1 operational since 2000 at Rome station. The methodology to retrieve the EDR and the Erythemal Daily Dose (EDD from the radiometer observations is described. Ground-based measurements were compared with satellite-derived total ozone and UV data from the Ozone Monitoring Instrument (OMI. OMI, onboard the NASA EOS Aura spacecraft, is a nadir viewing spectrometer that provides total ozone and surface UV retrievals. The results of the validation exercise showed satisfactory agreement between OMI and Brewer total ozone data, for both OMI-TOMS and OMI-DOAS ozone alghorithms (biases of −1.8% and −0.7%, respectively. Regarding UV data, OMI data overestimate ground-based erythemally weighted data retrieved from both Brewer and YES Radiometer (biases about 20%, probably because of the effect of absorbing aerosols in an urban site such as Rome.

  3. A CubeSat for Calibrating Ground-Based and Sub-Orbital Millimeter-Wave Polarimeters (CalSat)

    CERN Document Server

    Johnson, Bradley R; Drysdale, Timothy D; Kalman, Andrew; Fujikawa, Steve; Keating, Brian; Kaufman, Jon

    2015-01-01

    We describe a low-cost, open-access, CubeSat-based calibration instrument that is designed to support ground-based and sub-orbital experiments searching for various polarization signals in the cosmic microwave background (CMB). All modern CMB polarization experiments require a robust calibration program that will allow the effects of instrument-induced signals to be mitigated during data analysis. A bright, compact, and linearly polarized astrophysical source with polarization properties known to adequate precision does not exist. Therefore, we designed a space-based millimeter-wave calibration instrument, called CalSat, to serve as an open-access calibrator, and this paper describes the results of our design study. The calibration source on board CalSat is composed of five "tones" with one each at 47.1, 80.0, 140, 249 and 309 GHz. The five tones we chose are well matched to (i) the observation windows in the atmospheric transmittance spectra, (ii) the spectral bands commonly used in polarimeters by the CMB c...

  4. Further Studies of Forest Structure Parameter Retrievals Using the Echidna® Ground-Based Lidar

    Science.gov (United States)

    Strahler, A. H.; Yao, T.; Zhao, F.; Yang, X.; Schaaf, C.; Wang, Z.; Li, Z.; Woodcock, C. E.; Culvenor, D.; Jupp, D.; Newnham, G.; Lovell, J.

    2012-12-01

    Ongoing work with the Echidna® Validation Instrument (EVI), a full-waveform, ground-based scanning lidar (1064 nm) developed by Australia's CSIRO and deployed by Boston University in California conifers (2008) and New England hardwood and softwood (conifer) stands (2007, 2009, 2010), confirms the importance of slope correction in forest structural parameter retrieval; detects growth and disturbance over periods of 2-3 years; provides a new way to measure the between-crown clumping factor in leaf area index retrieval using lidar range; and retrieves foliage profiles with more lower-canopy detail than a large-footprint aircraft scanner (LVIS), while simulating LVIS foliage profiles accurately from a nadir viewpoint using a 3-D point cloud. Slope correction is important for accurate retrieval of forest canopy structural parameters, such as mean diameter at breast height (DBH), stem count density, basal area, and above-ground biomass. Topographic slope can induce errors in parameter retrievals because the horizontal plane of the instrument scan, which is used to identify, measure, and count tree trunks, will intersect trunks below breast height in the uphill direction and above breast height in the downhill direction. A test of three methods at southern Sierra Nevada conifer sites improved the range of correlations of these EVI-retrieved parameters with field measurements from 0.53-0.68 to 0.85-0.93 for the best method. EVI scans can detect change, including both growth and disturbance, in periods of two to three years. We revisited three New England forest sites scanned in 2007-2009 or 2007-2010. A shelterwood stand at the Howland Experimental Forest, Howland, Maine, showed increased mean DBH, above-ground biomass and leaf area index between 2007 and 2009. Two stands at the Harvard Forest, Petersham, Massachusetts, suffered reduced leaf area index and reduced stem count density as the result of an ice storm that damaged the stands. At one stand, broken tops were

  5. Spectral invariance hypothesis study of polarized reflectance with Ground-based Multiangle SpectroPolarimetric Imager (GroundMSPI)

    Science.gov (United States)

    Bradley, Christine L.; Kupinski, Meredith; Diner, David J.; Xu, Feng; Chipman, Russell A.

    2015-09-01

    Many models used to represent the boundary condition for the separation of atmospheric scattering from the surface reflectance in polarized remote sensing measurements assume that the polarized surface reflectance is spectrally neutral. The Spectral Invariance Hypothesis asserts that the magnitude and shape of the polarized bidirectional reflectance factor (pBRF) is equal for all wavelengths. In order to test this hypothesis, JPL's Ground-based Multiangle SpectroPolarimetric Imager (GroundMSPI) is used to measure polarization information of different outdoor surface types. GroundMSPI measures the linear polarization Stokes parameters (I, Q, U), at three wavelengths, 470 nm, 660 nm, and 865 nm. The camera is mounted on a two-axis gimbal to accurately select the view azimuth and elevation directions. On clear sky days we acquired day-long scans of scenes that contain various surface types such as grass, dirt, cement, brick, and asphalt and placed a Spectralon panel in the camera field of view to provide a reflectance reference. Over the course of each day, changing solar position in the sky provides a large range of scattering angles for this study. The polarized bidirectional reflectance factor (pBRF) is measured for the three wavelengths and the best fit slope of the spectral correlation is reported. This work reports the range of best fit slopes measured for five region types.

  6. Ground-based aerosol characterization during the South American Biomass Burning Analysis (SAMBBA) field experiment

    OpenAIRE

    De Brito, J.; Rizzo, L. V.; Morgan, W. T.; Coe, H.; Johnson, B; Haywood, J.; LONGO, K.; Freitas, S.; Andreae, M. O.; Artaxo, P.

    2014-01-01

    This paper investigates the physical and chemical characteristics of aerosols at ground level at a site heavily impacted by biomass burning. The site is located near Porto Velho, Rondônia, in the southwestern part of the Brazilian Amazon rainforest, and was selected for the deployment of a large suite of instruments, among them an Aerosol Chemical Speciation Monitor. Our measurements were made during the South American Biomass Burning Analysis (SAMBBA) field ...

  7. Response of base isolation system excited by spectrum compatible ground motions

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jung Han; Kim, Min Kyu; Choi, In Kil [KAERI, Daejeon (Korea, Republic of)

    2012-10-15

    Structures in a nuclear power system are designed to be elastic even under an earthquake excitation. However a structural component such as an isolator shows inelastic behavior inherently. For the seismic assessment of nonlinear structures, the response history analysis should be performed. Especially for the performance based design, where the failure probability of a system needs to be evaluated, the variation of response should be evaluated. In this study, the spectrum compatible ground motions, the artificial ground motion and the modified ground motion, were generated. Using these ground motions, the variations of seismic responses of a simplified isolation system were evaluated.

  8. Overview of the DACCIWA ground-based field campaign in southern West Africa

    Science.gov (United States)

    Lohou, Fabienne; Kalthoff, Norbert; Brooks, Barbara; Jegede, Gbenga; Adler, Bianca; Ajao, Adewale; Ayoola, Muritala; Babić, Karmen; Bessardon, Geoffrey; Delon, Claire; Dione, Cheikh; Handwerker, Jan; Jambert, Corinne; Kohler, Martin; Lothon, Marie; Pedruzo-Bagazgoitia, Xabier; Smith, Victoria; Sunmonu, Lukman; Wieser, Andreas; Derrien, Solène

    2017-04-01

    During June and July 2016, a ground-based field campaign took place in southern West Africa within the framework of the Dynamics-aerosol-chemistry-cloud interactions in West Africa (DACCIWA) project. In the investigated region, extended low-level stratus clouds form very frequently during night-time and persist long into the following day influencing the diurnal cycle of the atmospheric boundary layer and, hence, the regional climate. The motivation for the measurements was to identify the meteorological controls on the whole process chain from the formation of nocturnal stratus clouds, via the daytime transition to convective clouds and the formation of deep precipitating clouds. During the measurement period, extensive remote sensing and in-situ measurements were performed at three supersites in Kumasi (Ghana), Savè (Benin) and Ile-Ife (Nigeria). The gathered observations included the energy-balance components at the Earth's surface, the mean and turbulent conditions in the nocturnal and daytime ABL as well as the de- and entrainment processes between the ABL and the free troposphere. The meteorological measurements were supplemented by aerosol and air-chemistry observations. We will give an overview of the conducted measurements including instrument availability and strategy during intensive observation periods.

  9. Solar tower atmospheric Cherenkov effect experiment (STACEE) for ground based gamma ray astronomy

    Science.gov (United States)

    Bhattacharya, D.; Chantell, M. C.; Coppi, P.; Covault, C. E.; Dragovan, M.; Gregorich, D. T.; Hanna, D. S.; Mukherjee, R.; Ong, R. A.; Oser, S.; Ragan, K.; Tümer, O. T.; Williams, D. A.

    1997-05-01

    The STACEE experiment is being developed to study very high energy astrophysical gamma rays between 50 and 500 GeV. During the last few years this previously unexplored region has received much attention due to the detection of sources up to about 10 GeV by the EGRET instrument on board the CGRO. However, the paucity of detected sources at ~1 TeV indicates that fundamental processes working within these sources and/or in the intergalactic space are responsible for the cutoff in the photon spectra of the EGRET sources. The cutoff or the spectral change of these sources can be observed with ground-based Cherenkov detectors with a very low threshold. The use of large arrays of mirrors at solar power facilities is a promising way of lowering the threshold. Using this concept a series of tests were conducted at the National Solar Thermal Test Facility (NSTTF) at Sandia National Laboratories (Albuquerque, NM) with a full size prototype of the STACEE telescope system. The tests show that STACEE will be capable of meaningful exploration of the gamma-ray sky between 50 and 500 GeV with good sensitivity.

  10. Ground-based near-infrared observations of water vapour in the Venus troposphere

    CERN Document Server

    Chamberlain, S; Crisp, D; Meadows, V S; 10.1016/j.icarus.2012.11.014

    2012-01-01

    We present a study of water vapour in the Venus troposphere obtained by modelling specific water vapour absorption bands within the 1.18 \\mu m window. We compare the results with the normal technique of obtaining the abundance by matching the peak of the 1.18 \\mu m window. Ground-based infrared imaging spectroscopy of the night side of Venus was obtained with the Anglo-Australian Telescope and IRIS2 instrument with a spectral resolving power of R ~ 2400. The spectra have been fitted with modelled spectra simulated using the radiative transfer model VSTAR. We find a best fit abundance of 31 ppmv (-6 + 9 ppmv), which is in agreement with recent results by B\\'ezard et al. 2011 using VEX/SPICAV (R ~ 1700) and contrary to prior results by B\\'ezard et al. 2009 of 44 ppmv (+/-9 ppmv) using VEX/VIRTIS-M (R ~ 200) data analyses. Comparison studies are made between water vapour abundances determined from the peak of the 1.18 \\mu m window and abundances determined from different water vapour absorption features within t...

  11. CO2 Total Column Variability From Ground-Based FTIR Measurements Over Central Mexico

    Science.gov (United States)

    Baylon, J. L.; Stremme, W.; Plaza, E.; Bezanilla, A.; Grutter, M.; Hase, F.; Blumenstock, T.

    2014-12-01

    There are now several space missions dedicated to measure greenhouse gases in order to improve the understanding of the carbon cycle. Ground based measurement sites are of great value in the validation process, however there are only a few stations in tropical latitudes. We present measurements of solar-absorption infrared spectra recorded on two locations over Central Mexico: the High-Altitude Station Altzomoni (19.12 N, 98.65 W), located in the Izta-Popo National Park outside of Mexico City; and the UNAM's Atmospheric Observatory (19.32 N, 99.17 W) in Mexico City. These measurements were performed using a high resolution Fourier transform infrared spectrometer FTIR (Bruker, HR 120/5) at Altzomoni and a moderate resolution FTIR (Bruker, Vertex 80) within the city. In this work, we present the first results for total vertical columns of CO2 derived from near-infrared spectra recorded at both locations using the retrieval code PROFFIT. We present the seasonal cycle and variability from the measurements, as well as the full diagnostics of the retrieval in order assess its quality and discuss the differences of both instruments and locations (altitudes, urban vs remote). This work aims to contribute to generate high quality datasets for satellite validation.

  12. A Ground-Based Search for Thermal Emission from the Exoplanet TrES-1

    CERN Document Server

    Knutson, Heather A; Deming, Drake; Richardson, L Jeremy

    2007-01-01

    Eclipsing planetary systems give us an important window on extrasolar planet atmospheres. By measuring the depth of the secondary eclipse, when the planet moves behind the star, we can estimate the strength of the thermal emission from the day side of the planet. Attaining a ground-based detection of one of these eclipses has proven to be a significant challenge, as time-dependent variations in instrument throughput and atmospheric seeing and absorption overwhelm the small signal of the eclipse at infrared wavelengths. We gathered a series of simultaneous L grism spectra of the transiting planet system TrES-1 and a nearby comparison star of comparable brightness, allowing us to correct for these effects in principle. Combining the data from two eclipses, we demonstrate a detection sensitivity of 0.15% in the eclipse depth relative to the stellar flux. This approaches the sensitivity required to detect the planetary emission, which theoretical models predict should lie between 0.05-0.1% of the stellar flux in ...

  13. On the atmospheric limitations of ground-based submillimetre astronomy using array receivers

    CERN Document Server

    Archibald, E N; Holland, W S; Coulson, I M; Jessop, N E; Stevens, J A; Robson, E I; Tilanus, R P J; Duncan, W D; Lightfoot, J F

    2002-01-01

    The calibration of ground-based submillimetre observations has always been a difficult process. We discuss how to overcome the limitations imposed by the submillimetre atmosphere. Novel ways to improve line-of-sight opacity estimates are presented, resulting in tight relations between opacities at different wavelengths. The submillimetre camera SCUBA, mounted on the JCMT, is the first large-scale submillimetre array, and as such is ideal for combatting the effects of the atmosphere. For example, we find that the off-source pixels are crucial for removing sky-noise. Benefitting from several years of SCUBA operation, a database of deep SCUBA observations has been constructed to better understand the nature of sky-noise and the effects of the atmosphere on instrument sensitivity. This has revealed several results. Firstly, there is evidence for positive correlations between sky-noise and seeing and sky-noise and sky opacity. Furthermore, 850-micron and 450-micron sky-noise are clearly correlated, suggesting that...

  14. OPUS BBM: Its performance and early results of ground-based measurements

    Science.gov (United States)

    Kuze, A.; Shibasaki, K.; Sano, T.; Kawashima, T.; Miyamura, N.; Tange, Y.; Yui, Y.; Suzuki, M.; Ogawa, T.

    2003-04-01

    OPUS(Ozone and Pollution measuring Ultraviolet Spectrometer) is the satellite-borne instrument for future Japanese mission. Its scientific goal is to monitor the tropospheric urban and severely polluted chemical species such as SO2 and NO2 as well as total and tropospheric ozone. Now its BBM has been constructed and under performance check. Several checks are now being made on performances under thermal and vacum environments suffered in orbit. The OPUS BBM showed very stable perfomance as expected. The CMOS type array detector reveals very low noise and high quantum efficiency suitable for space use. In this paper we show the results of performance check of OPUS BBM. We also carried out the ground-based, zenith sky (scatter light) measurement for checking the S/N ratio of OPUS BBM as well as for demonstrating its ability to derive NO2 in the atmosphere. A preliminary analysis result is shown, and also shown is the result of algorithm study for space mission.

  15. Multi-component vertical profile retrievals for ground-based MAX-DOAS

    Science.gov (United States)

    Irie, Hitoshi; Kanaya, Yugo; Takashima, Hisahiro; van Roozendael, Michel; Wittrock, Folkard; Piters, Ankie

    2010-05-01

    We attempt to retrieve lower-tropospheric vertical profile information for 8 components from ground-based Multi-Axis Differential Optical Absorption Spectroscopy (MAX-DOAS) measurements. The components retrieved include aerosol extinction coefficients (AEC) at two wavelengths 357 and 476 nm, NO2, HCHO, CHOCHO, H2O, SO2, and O3 volume mixing ratios (VMRs). This method was applied to MAX-DOAS observations performed at Cabauw, the Netherlands (52.0°N, 4.9°E) in June-July 2009 during the Cabauw Intercomparison campaign of Nitrogen Dioxide measuring Instruments (CINDI) campaign. For the lowest layer of retrieved profiles at 0-1 km, two channels of AEC values reveal consistent variations. NO2 showed typical diurnal variations with maximum in early morning and minimum in the afternoon. Positive correlations between HCHO and CHOCHO were often seen. H2O VMR agreed well with that derived from NCEP surface data, and was used to judge cloudy cases after conversion to relative humidity. All these results support the capability of MAX-DOAS observations applicable to various air quality studies. Similar multi-component retrievals applied to observations in Japan are also presented in this talk.

  16. (Environmental investigation of ground water contamination at Wright-Patterson Air Force Base, Ohio)

    Energy Technology Data Exchange (ETDEWEB)

    1992-03-01

    This report presents information related to the sampling of ground water at the Wright-Patterson Air Force Base. It is part of an investigation into possible ground water contamination. Information concerns well drilling/construction; x-ray diffraction and sampling; soil boring logs; and chain-of-custody records.

  17. Polarimetry noise in fiber-based optical coherence tomography instrumentation

    Science.gov (United States)

    Zhang, Ellen Ziyi; Vakoc, Benjamin J.

    2011-01-01

    High noise levels in fiber-based polarization-sensitive optical coherence tomography (PS-OCT) have broadly limited its clinical utility. In this study we investigate contribution of polarization mode dispersion (PMD) to the polarimetry noise. We develop numerical models of the PS-OCT system including PMD and validate these models with empirical data. Using these models, we provide a framework for predicting noise levels, for processing signals to reduce noise, and for designing an optimized system. PMID:21935044

  18. A knowledge base system for ground control over abandoned mines

    Energy Technology Data Exchange (ETDEWEB)

    Nazimko, V.V.; Zviagilsky, E.L. [Donetsk State Technical University, Donetsk (Ukraine)

    1999-07-01

    The knowledge of engineering systems has been developed to choose optimal technology for subsidence prevention over abandoned mines. The expert system treats a specific case, maps consequences of actions and derives relevant technology (or a set of technologies) that should be used to prevent ground subsidence. Input parameters that characterise the case are treated using fuzzy logic and are then fed to a neural network. The network has been successfully trained by a backpropagation algorithm on the basis of three fuzzy rules. 5 refs., 2 figs., 3 tabs.

  19. Ground-based measurement of surface temperature and thermal emissivity

    Science.gov (United States)

    Owe, M.; Van De Griend, A. A.

    1994-01-01

    Motorized cable systems for transporting infrared thermometers have been used successfully during several international field campaigns. Systems may be configured with as many as four thermal sensors up to 9 m above the surface, and traverse a 30 m transect. Ground and canopy temperatures are important for solving the surface energy balance. The spatial variability of surface temperature is often great, so that averaged point measurements result in highly inaccurate areal estimates. The cable systems are ideal for quantifying both temporal and spatial variabilities. Thermal emissivity is also necessary for deriving the absolute physical temperature, and measurements may be made with a portable measuring box.

  20. Reflectances from a supercontinuum laser-based instrument: hyperspectral, polarimetric and angular measurements.

    Science.gov (United States)

    Ceolato, Romain; Riviere, Nicolas; Hespel, Laurent

    2012-12-31

    Recent developments of active hyperspectral systems require optical characterization of man-made materials for instrument calibration. This work presents an original supercontinuum laser-based instrument designed by Onera, The French Aerospace Lab, for fast hyperspectral polarimetric and angular reflectances measurements. The spectral range is from 480 nm to 1000 nm with a 1 nm spectral resolution. Different polarization configurations are made possible in whole spectrum. This paper reviews the design and the calibration of the instrument. Hyper-spectral polarimetric and angular reflectances are measured for reference and man-made materials such as paint coatings. Physical properties of reflectances as positivity, energy conservation and Helmholtz reciprocity are retrieved from measurements.

  1. Commercial off the Shelf Ground Control Supports Calibration and Conflation from Ground to Space Based Sensors

    Science.gov (United States)

    Danielová, M.; Hummel, P.

    2016-06-01

    The need for rapid deployment of aerial and satellite imagery in support of GIS and engineering integration projects require new sources of geodetic control to ensure the accuracy for geospatial projects. In the past, teams of surveyors would need to deploy to project areas to provide targeted or photo identifiable points that are used to provide data for orthorecificaion, QA/QC and calibration for multi-platform sensors. The challenge of integrating street view, UAS, airborne and Space based sensors to produce the common operational picture requires control to tie multiple sources together. Today commercial off the shelf delivery of existing photo identifiable control is increasing the speed of deployment of this data without having to revisit sites over and over again. The presentation will discuss the processes developed by CompassData to build a global library of 40,000 control points available today. International Organization for Standardization (ISO) based processes and initiatives ensure consistent quality of survey data, photo identifiable features selected and meta data to support photogrammetrist, engineers and GIS professionals to quickly deliver projects with better accuracy.

  2. Principle and Design of a Single-phase Inverter Based Grounding System for Neutral-to-ground Voltage Compensation in Distribution Networks

    DEFF Research Database (Denmark)

    Wang, Wen; Yan, Lingjie; Zeng, Xiangjun

    2017-01-01

    Neutral-to-ground overvoltage may occur in non-effectively grounded power systems because of the distributed parameters asymmetry and resonance between Petersen coil and distributed capacitances. Thus, the constraint of neutral-to-ground voltage is critical for the safety of distribution networks....... In this paper, an active grounding system based on single-phase inverter and its control parameter design method is proposed to achieve this objective. Relationship between its output current and neutral-to-ground voltage is derived to explain the principle of neutral-to-ground voltage compensation. Then...... margin subjecting to large range of load change. The PI method is taken as the comparative method and the performances of both control methods are presented in detail. Experimental results prove the effectiveness and novelty of the proposed grounding system and control method....

  3. Calibration of ground-based Lidar instrument WLS7-318

    DEFF Research Database (Denmark)

    Yordanova, Ginka; Gómez Arranz, Paula

    This report presents the result of the lidar calibration performed for the given WLS7 Windcube at DTU’s test site for large wind turbines at Høvsøre, Denmark. Calibration is here understood as the establishment of a relation between the reference wind speed measurements with measurement uncertain......This report presents the result of the lidar calibration performed for the given WLS7 Windcube at DTU’s test site for large wind turbines at Høvsøre, Denmark. Calibration is here understood as the establishment of a relation between the reference wind speed measurements with measurement...... uncertainties provided by measurement standard and corresponding lidar wind speed indications with associated measurement uncertainties. The lidar calibration concerns the 10 minute mean wind speed measurements. The comparison of the lidar measurements of the wind direction with that from wind vanes...

  4. Calibration of ground-based Lidar instrument WLS866-12

    DEFF Research Database (Denmark)

    Yordanova, Ginka; Gómez Arranz, Paula

    This report presents the result of the lidar calibration performed for the given WLS7 Windcube at DTU’s test site for large wind turbines at Høvsøre, Denmark. Calibration is here understood as the establishment of a relation between the reference wind speed measurements with measurement uncertain......This report presents the result of the lidar calibration performed for the given WLS7 Windcube at DTU’s test site for large wind turbines at Høvsøre, Denmark. Calibration is here understood as the establishment of a relation between the reference wind speed measurements with measurement...... uncertainties provided by measurement standard and corresponding lidar wind speed indications with associated measurement uncertainties. The lidar calibration concerns the 10 minute mean wind speed measurements. The comparison of the lidar measurements of the wind direction with that from wind vanes...

  5. Calibration of ground-based lidar instrument WLS7-218

    DEFF Research Database (Denmark)

    Gómez Arranz, Paula; Wagner, Rozenn

    This report presents the result of the lidar calibration performed for the given WLS7 Windcube at DTU’s test site for large wind turbine at Høvsøre, Denmark. Calibration is here understood as the establishment of a relation between the reference wind speed measurements with measurement uncertaint......This report presents the result of the lidar calibration performed for the given WLS7 Windcube at DTU’s test site for large wind turbine at Høvsøre, Denmark. Calibration is here understood as the establishment of a relation between the reference wind speed measurements with measurement...... uncertainties provided by measurement standard and corresponding lidar wind speed indications with associated measurement uncertainties. The lidar calibration concerns the 10 minute mean wind speed measurements. The comparison of the lidar measurements of the wind direction with that from wind vanes...

  6. Calibration of ground-based lidar instrument WLS7-99

    DEFF Research Database (Denmark)

    Gómez Arranz, Paula; Wagner, Rozenn

    This report presents the result of the lidar calibration performed for the given WLS7 Windcube at DTU’s test site for large wind turbine at Høvsøre, Denmark. Calibration is here understood as the establishment of a relation between the reference wind speed measurements with measurement uncertaint......This report presents the result of the lidar calibration performed for the given WLS7 Windcube at DTU’s test site for large wind turbine at Høvsøre, Denmark. Calibration is here understood as the establishment of a relation between the reference wind speed measurements with measurement...... uncertainties provided by measurement standard and corresponding lidar wind speed indications with associated measurement uncertainties. The lidar calibration concerns the 10 minute mean wind speed measurements. The comparison of the lidar measurements of the wind direction with that from wind vanes...

  7. Test of ground-based lidar instrument WLS7-159

    DEFF Research Database (Denmark)

    Gómez Arranz, Paula; Wagner, Rozenn

    This report presents the result of the test performed for the given Windcube at DTU’s test site for large wind turbine at Høvsøre, Denmark. The test aims at establishing a relation between the reference wind measurements and corresponding lidar wind indications, and evaluating a set of quality...

  8. Calibration of ground-based Lidar instrument WLS7-283

    DEFF Research Database (Denmark)

    Gómez Arranz, Paula; Courtney, Michael

    This report presents the result of the lidar calibration performed for the given WLS7 Windcube at DTU’s test site for large wind turbines at Høvsøre, Denmark. Calibration is here understood as the establishment of a relation between the reference wind speed measurements with measurement uncertain......This report presents the result of the lidar calibration performed for the given WLS7 Windcube at DTU’s test site for large wind turbines at Høvsøre, Denmark. Calibration is here understood as the establishment of a relation between the reference wind speed measurements with measurement...... uncertainties provided by measurement standard and corresponding lidar wind speed indications with associated measurement uncertainties. The lidar calibration concerns the 10 minute mean wind speed measurements. The comparison of the lidar measurements of the wind direction with that from wind vanes...

  9. Calibration of ground-based Lidar instrument WLS7-37

    DEFF Research Database (Denmark)

    Gómez Arranz, Paula; Courtney, Michael

    This report presents the result of the lidar calibration performed for the given WLS7 Windcube at DTU’s test site for large wind turbines at Høvsøre, Denmark. Calibration is here understood as the establishment of a relation between the reference wind speed measurements with measurement uncertain......This report presents the result of the lidar calibration performed for the given WLS7 Windcube at DTU’s test site for large wind turbines at Høvsøre, Denmark. Calibration is here understood as the establishment of a relation between the reference wind speed measurements with measurement...... uncertainties provided by measurement standard and corresponding lidar wind speed indications with associated measurement uncertainties. The lidar calibration concerns the 10 minute mean wind speed measurements. The comparison of the lidar measurements of the wind direction with that from wind vanes...

  10. Calibration of ground-based Lidar instrument WLS7-341

    DEFF Research Database (Denmark)

    Yordanova, Ginka; Gómez Arranz, Paula

    This report presents the result of the lidar calibration performed for the given WLS7 Windcube at DTU’s test site for large wind turbines at Høvsøre, Denmark. Calibration is here understood as the establishment of a relation between the reference wind speed measurements with measurement uncertain......This report presents the result of the lidar calibration performed for the given WLS7 Windcube at DTU’s test site for large wind turbines at Høvsøre, Denmark. Calibration is here understood as the establishment of a relation between the reference wind speed measurements with measurement...... uncertainties provided by measurement standard and corresponding lidar wind speed indications with associated measurement uncertainties. The lidar calibration concerns the 10 minute mean wind speed measurements. The comparison of the lidar measurements of the wind direction with that from wind vanes...

  11. Calibration of ground-based lidar instrument WLS7-219

    DEFF Research Database (Denmark)

    Gómez Arranz, Paula; Wagner, Rozenn

    This report presents the result of the lidar calibration performed for the given WLS7 Windcube at DTU’s test site for large wind turbine at Høvsøre, Denmark. Calibration is here understood as the establishment of a relation between the reference wind speed measurements with measurement uncertaint......This report presents the result of the lidar calibration performed for the given WLS7 Windcube at DTU’s test site for large wind turbine at Høvsøre, Denmark. Calibration is here understood as the establishment of a relation between the reference wind speed measurements with measurement...... uncertainties provided by measurement standard and corresponding lidar wind speed indications with associated measurement uncertainties. The lidar calibration concerns the 10 minute mean wind speed measurements. The comparison of the lidar measurements of the wind direction with that from wind vanes...

  12. Calibration of ground-based Lidar instrument WLS866-1

    DEFF Research Database (Denmark)

    Gómez Arranz, Paula; Courtney, Michael

    This report presents the result of the lidar calibration performed for the given WLS7 Windcube at DTU’s test site for large wind turbines at Høvsøre, Denmark. Calibration is here understood as the establishment of a relation between the reference wind speed measurements with measurement uncertain......This report presents the result of the lidar calibration performed for the given WLS7 Windcube at DTU’s test site for large wind turbines at Høvsøre, Denmark. Calibration is here understood as the establishment of a relation between the reference wind speed measurements with measurement...... uncertainties provided by measurement standard and corresponding lidar wind speed indications with associated measurement uncertainties. The lidar calibration concerns the 10 minute mean wind speed measurements. The comparison of the lidar measurements of the wind direction with that from wind vanes...

  13. Calibration of ground-based Lidar instrument WLS7-327

    DEFF Research Database (Denmark)

    Yordanova, Ginka; Gómez Arranz, Paula

    This report presents the result of the lidar calibration performed for the given WLS7 Windcube at DTU’s test site for large wind turbines at Høvsøre, Denmark. Calibration is here understood as the establishment of a relation between the reference wind speed measurements with measurement uncertain......This report presents the result of the lidar calibration performed for the given WLS7 Windcube at DTU’s test site for large wind turbines at Høvsøre, Denmark. Calibration is here understood as the establishment of a relation between the reference wind speed measurements with measurement...... uncertainties provided by measurement standard and corresponding lidar wind speed indications with associated measurement uncertainties. The lidar calibration concerns the 10 minute mean wind speed measurements. The comparison of the lidar measurements of the wind direction with that from wind vanes...

  14. Calibration of ground-based Lidar instrument WLS866-13

    DEFF Research Database (Denmark)

    Yordanova, Ginka; Gómez Arranz, Paula

    This report presents the result of the lidar calibration performed for the given WLS7 Windcube at DTU’s test site for large wind turbines at Høvsøre, Denmark. Calibration is here understood as the establishment of a relation between the reference wind speed measurements with measurement uncertain......This report presents the result of the lidar calibration performed for the given WLS7 Windcube at DTU’s test site for large wind turbines at Høvsøre, Denmark. Calibration is here understood as the establishment of a relation between the reference wind speed measurements with measurement...... uncertainties provided by measurement standard and corresponding lidar wind speed indications with associated measurement uncertainties. The lidar calibration concerns the 10 minute mean wind speed measurements. The comparison of the lidar measurements of the wind direction with that from wind vanes...

  15. Calibration of ground-based Lidar instrument WLS7-218

    DEFF Research Database (Denmark)

    Yordanova, Ginka; Gómez Arranz, Paula

    This report presents the result of the lidar calibration performed for the given WLS7 Windcube at DTU’s test site for large wind turbines at Høvsøre, Denmark. Calibration is here understood as the establishment of a relation between the reference wind speed measurements with measurement uncertain......This report presents the result of the lidar calibration performed for the given WLS7 Windcube at DTU’s test site for large wind turbines at Høvsøre, Denmark. Calibration is here understood as the establishment of a relation between the reference wind speed measurements with measurement...... uncertainties provided by measurement standard and corresponding lidar wind speed indications with associated measurement uncertainties. The lidar calibration concerns the 10 minute mean wind speed measurements. The comparison of the lidar measurements of the wind direction with that from wind vanes...

  16. Calibration of ground-based lidar instrument WLS7-213

    DEFF Research Database (Denmark)

    Gómez Arranz, Paula; Courtney, Michael

    This report presents the result of the lidar calibration performed for the given WLS7 Windcube at DTU’s test site for large wind turbine at Høvsøre, Denmark. Calibration is here understood as the establishment of a relation between the reference wind speed measurements with measurement uncertaint......This report presents the result of the lidar calibration performed for the given WLS7 Windcube at DTU’s test site for large wind turbine at Høvsøre, Denmark. Calibration is here understood as the establishment of a relation between the reference wind speed measurements with measurement...... uncertainties provided by measurement standard and corresponding lidar wind speed indications with associated measurement uncertainties. The lidar calibration concerns the 10 minute mean wind speed measurements. The comparison of the lidar measurements of the wind direction with that from wind vanes...

  17. Calibration of ground-based Lidar instrument WLS7-73

    DEFF Research Database (Denmark)

    Yordanova, Ginka; Gómez Arranz, Paula

    This report presents the result of the lidar calibration performed for the given WLS7 Windcube at DTU’s test site for large wind turbines at Høvsøre, Denmark. Calibration is here understood as the establishment of a relation between the reference wind speed measurements with measurement uncertain......This report presents the result of the lidar calibration performed for the given WLS7 Windcube at DTU’s test site for large wind turbines at Høvsøre, Denmark. Calibration is here understood as the establishment of a relation between the reference wind speed measurements with measurement...... uncertainties provided by measurement standard and corresponding lidar wind speed indications with associated measurement uncertainties. The lidar calibration concerns the 10 minute mean wind speed measurements. The comparison of the lidar measurements of the wind direction with that from wind vanes...

  18. Calibration of ground-based Lidar instrument WLS7-222

    DEFF Research Database (Denmark)

    Yordanova, Ginka; Gómez Arranz, Paula

    This report presents the result of the lidar calibration performed for the given WLS7 Windcube at DTU’s test site for large wind turbines at Høvsøre, Denmark. Calibration is here understood as the establishment of a relation between the reference wind speed measurements with measurement uncertain......This report presents the result of the lidar calibration performed for the given WLS7 Windcube at DTU’s test site for large wind turbines at Høvsøre, Denmark. Calibration is here understood as the establishment of a relation between the reference wind speed measurements with measurement...... uncertainties provided by measurement standard and corresponding lidar wind speed indications with associated measurement uncertainties. The lidar calibration concerns the 10 minute mean wind speed measurements. The comparison of the lidar measurements of the wind direction with that from wind vanes...

  19. Calibration of ground-based Lidar instrument WLS866-8

    DEFF Research Database (Denmark)

    Yordanova, Ginka; Gómez Arranz, Paula

    This report presents the result of the lidar calibration performed for the given WLS7 Windcube at DTU’s test site for large wind turbines at Høvsøre, Denmark. Calibration is here understood as the establishment of a relation between the reference wind speed measurements with measurement uncertain......This report presents the result of the lidar calibration performed for the given WLS7 Windcube at DTU’s test site for large wind turbines at Høvsøre, Denmark. Calibration is here understood as the establishment of a relation between the reference wind speed measurements with measurement...... uncertainties provided by measurement standard and corresponding lidar wind speed indications with associated measurement uncertainties. The lidar calibration concerns the 10 minute mean wind speed measurements. The comparison of the lidar measurements of the wind direction with that from wind vanes...

  20. Calibration of ground-based Lidar instrument WLS7-226

    DEFF Research Database (Denmark)

    Gómez Arranz, Paula; Wagner, Rozenn

    This report presents the result of the lidar calibration performed for the given WLS7 Windcube at DTU’s test site for large wind turbines at Høvsøre, Denmark. Calibration is here understood as the establishment of a relation between the reference wind speed measurements with measurement uncertain......This report presents the result of the lidar calibration performed for the given WLS7 Windcube at DTU’s test site for large wind turbines at Høvsøre, Denmark. Calibration is here understood as the establishment of a relation between the reference wind speed measurements with measurement...... uncertainties provided by measurement standard and corresponding lidar wind speed indications with associated measurement uncertainties. The lidar calibration concerns the 10 minute mean wind speed measurements. The comparison of the lidar measurements of the wind direction with that from wind vanes...

  1. Calibration of ground-based Lidar instrument WLS7-34

    DEFF Research Database (Denmark)

    Yordanova, Ginka; Gómez Arranz, Paula

    This report presents the result of the lidar calibration performed for the given WLS7 Windcube at DTU’s test site for large wind turbines at Høvsøre, Denmark. Calibration is here understood as the establishment of a relation between the reference wind speed measurements with measurement uncertain......This report presents the result of the lidar calibration performed for the given WLS7 Windcube at DTU’s test site for large wind turbines at Høvsøre, Denmark. Calibration is here understood as the establishment of a relation between the reference wind speed measurements with measurement...... uncertainties provided by measurement standard and corresponding lidar wind speed indications with associated measurement uncertainties. The lidar calibration concerns the 10 minute mean wind speed measurements. The comparison of the lidar measurements of the wind direction with that from wind vanes...

  2. Calibration of ground-based Lidar instrument WLS7-369

    DEFF Research Database (Denmark)

    Yordanova, Ginka; Gómez Arranz, Paula

    This report presents the result of the lidar calibration performed for the given WLS7 Windcube at DTU’s test site for large wind turbines at Høvsøre, Denmark. Calibration is here understood as the establishment of a relation between the reference wind speed measurements with measurement uncertain......This report presents the result of the lidar calibration performed for the given WLS7 Windcube at DTU’s test site for large wind turbines at Høvsøre, Denmark. Calibration is here understood as the establishment of a relation between the reference wind speed measurements with measurement...... uncertainties provided by measurement standard and corresponding lidar wind speed indications with associated measurement uncertainties. The lidar calibration concerns the 10 minute mean wind speed measurements. The comparison of the lidar measurements of the wind direction with that from wind vanes...

  3. Calibration of ground-based Lidar instrument WLS7-150

    DEFF Research Database (Denmark)

    Yordanova, Ginka; Gómez Arranz, Paula

    This report presents the result of the lidar calibration performed for the given WLS7 Windcube at DTU’s test site for large wind turbines at Høvsøre, Denmark. Calibration is here understood as the establishment of a relation between the reference wind speed measurements with measurement uncertain......This report presents the result of the lidar calibration performed for the given WLS7 Windcube at DTU’s test site for large wind turbines at Høvsøre, Denmark. Calibration is here understood as the establishment of a relation between the reference wind speed measurements with measurement...... uncertainties provided by measurement standard and corresponding lidar wind speed indications with associated measurement uncertainties. The lidar calibration concerns the 10 minute mean wind speed measurements. The comparison of the lidar measurements of the wind direction with that from wind vanes...

  4. Calibration of ground-based Lidar instrument WLS866-5

    DEFF Research Database (Denmark)

    Yordanova, Ginka; Gómez Arranz, Paula

    This report presents the result of the lidar calibration performed for the given WLS7 Windcube at DTU’s test site for large wind turbines at Høvsøre, Denmark. Calibration is here understood as the establishment of a relation between the reference wind speed measurements with measurement uncertain......This report presents the result of the lidar calibration performed for the given WLS7 Windcube at DTU’s test site for large wind turbines at Høvsøre, Denmark. Calibration is here understood as the establishment of a relation between the reference wind speed measurements with measurement...... uncertainties provided by measurement standard and corresponding lidar wind speed indications with associated measurement uncertainties. The lidar calibration concerns the 10 minute mean wind speed measurements. The comparison of the lidar measurements of the wind direction with that from wind vanes...

  5. Calibration of ground-based lidar instrument WLS7-151

    DEFF Research Database (Denmark)

    Gómez Arranz, Paula; Wagner, Rozenn

    This report presents the result of the lidar calibration performed for the given WLS7 Windcube at DTU’s test site for large wind turbine at Høvsøre, Denmark. Calibration is here understood as the establishment of a relation between the reference wind speed measurements with measurement uncertaint......This report presents the result of the lidar calibration performed for the given WLS7 Windcube at DTU’s test site for large wind turbine at Høvsøre, Denmark. Calibration is here understood as the establishment of a relation between the reference wind speed measurements with measurement...... uncertainties provided by measurement standard and corresponding lidar wind speed indications with associated measurement uncertainties. The lidar calibration concerns the 10 minute mean wind speed measurements. The comparison of the lidar measurements of the wind direction with that from wind vanes...

  6. Calibration of ground-based Lidar instrument WLS7-264

    DEFF Research Database (Denmark)

    Yordanova, Ginka; Gómez Arranz, Paula

    This report presents the result of the lidar calibration performed for the given WLS7 Windcube at DTU’s test site for large wind turbines at Høvsøre, Denmark. Calibration is here understood as the establishment of a relation between the reference wind speed measurements with measurement uncertain......This report presents the result of the lidar calibration performed for the given WLS7 Windcube at DTU’s test site for large wind turbines at Høvsøre, Denmark. Calibration is here understood as the establishment of a relation between the reference wind speed measurements with measurement...... uncertainties provided by measurement standard and corresponding lidar wind speed indications with associated measurement uncertainties. The lidar calibration concerns the 10 minute mean wind speed measurements. The comparison of the lidar measurements of the wind direction with that from wind vanes...

  7. Test of ground-based Lidar instrument WLS200S-10

    DEFF Research Database (Denmark)

    Gómez Arranz, Paula

    This report presents the result of the test performed for the given Windcube at DTU’s test site for large wind turbine at Høvsøre, Denmark. The test aims at establishing a relation between the reference wind measurements and corresponding lidar wind indications, and evaluating a set of quality...

  8. Calibration of ground-based lidar instrument WLS7-221

    DEFF Research Database (Denmark)

    Gómez Arranz, Paula; Wagner, Rozenn

    This report presents the result of the lidar calibration performed for the given WLS7 Windcube at DTU’s test site for large wind turbine at Høvsøre, Denmark. Calibration is here understood as the establishment of a relation between the reference wind speed measurements with measurement uncertaint......This report presents the result of the lidar calibration performed for the given WLS7 Windcube at DTU’s test site for large wind turbine at Høvsøre, Denmark. Calibration is here understood as the establishment of a relation between the reference wind speed measurements with measurement...... uncertainties provided by measurement standard and corresponding lidar wind speed indications with associated measurement uncertainties. The lidar calibration concerns the 10 minute mean wind speed measurements. The comparison of the lidar measurements of the wind direction with that from wind vanes...

  9. Calibration of ground-based Lidar instrument WLS7-91

    DEFF Research Database (Denmark)

    Yordanova, Ginka; Wagner, Rozenn

    This report presents the result of the lidar calibration performed for the given WLS7 Windcube at DTU’s test site for large wind turbines at Høvsøre, Denmark. Calibration is here understood as the establishment of a relation between the reference wind speed measurements with measurement uncertain......This report presents the result of the lidar calibration performed for the given WLS7 Windcube at DTU’s test site for large wind turbines at Høvsøre, Denmark. Calibration is here understood as the establishment of a relation between the reference wind speed measurements with measurement...... uncertainties provided by measurement standard and corresponding lidar wind speed indications with associated measurement uncertainties. The lidar calibration concerns the 10 minute mean wind speed measurements. The comparison of the lidar measurements of the wind direction with that from wind vanes...

  10. Calibration of ground-based Lidar instrument WLS7-66

    DEFF Research Database (Denmark)

    Yordanova, Ginka; Gómez Arranz, Paula

    This report presents the result of the lidar calibration performed for the given WLS7 Windcube at DTU’s test site for large wind turbines at Høvsøre, Denmark. Calibration is here understood as the establishment of a relation between the reference wind speed measurements with measurement uncertain......This report presents the result of the lidar calibration performed for the given WLS7 Windcube at DTU’s test site for large wind turbines at Høvsøre, Denmark. Calibration is here understood as the establishment of a relation between the reference wind speed measurements with measurement...... uncertainties provided by measurement standard and corresponding lidar wind speed indications with associated measurement uncertainties. The lidar calibration concerns the 10 minute mean wind speed measurements. The comparison of the lidar measurements of the wind direction with that from wind vanes...

  11. Calibration of ground-based Lidar instrument WLS7-284

    DEFF Research Database (Denmark)

    Yordanova, Ginka; Gómez Arranz, Paula

    This report presents the result of the lidar calibration performed for the given WLS7 Windcube at DTU’s test site for large wind turbines at Høvsøre, Denmark. Calibration is here understood as the establishment of a relation between the reference wind speed measurements with measurement uncertain......This report presents the result of the lidar calibration performed for the given WLS7 Windcube at DTU’s test site for large wind turbines at Høvsøre, Denmark. Calibration is here understood as the establishment of a relation between the reference wind speed measurements with measurement...... uncertainties provided by measurement standard and corresponding lidar wind speed indications with associated measurement uncertainties. The lidar calibration concerns the 10 minute mean wind speed measurements. The comparison of the lidar measurements of the wind direction with that from wind vanes...

  12. GENIE: a ground-based European nulling instrument at ESO very large telescope interferometer

    NARCIS (Netherlands)

    Gondoin, P.; Hartog, R. den; Fridlund, M.; Fabry, P.; Stankov, A.; Peacock, A.; Volonte, S.; Puech, F.; Delplancke, F.; Gitton, P.; Glindemann, A.; Paresce, F.; Richichi, A.; Barillot, M.; Absil, O.; Cassaing, F.; Foresto, V.C. du; Kervella, P.; Perrin, G.; Ruilier, C.; Flatscher, R.; Bokhove, H.; Ergenzinger, K.; Quirrenbach, A.; Wallner, O.; Alves, J.; Herbst, T.; Mourard, D.; Neuhäuser, R.; Ségransan, D.; Waters, R.; White, G.J.

    2008-01-01

    Darwin is one of the most challenging space projects ever considered by the European Space Agency (ESA). Its principal objectives are to detect Earth-like planets around nearby stars, to analyze the composition of their atmospheres and to assess their ability to sustain life as we know it. Darwin is

  13. Calibration of ground-based lidar instrument WLS7-202

    DEFF Research Database (Denmark)

    Gómez Arranz, Paula; Courtney, Michael

    This report presents the result of the lidar calibration performed for the given WLS7 Windcube at DTU’s test site for large wind turbine at Høvsøre, Denmark. Calibration is here understood as the establishment of a relation between the reference wind speed measurements with measurement uncertaint......This report presents the result of the lidar calibration performed for the given WLS7 Windcube at DTU’s test site for large wind turbine at Høvsøre, Denmark. Calibration is here understood as the establishment of a relation between the reference wind speed measurements with measurement...... uncertainties provided by measurement standard and corresponding lidar wind speed indications with associated measurement uncertainties. The lidar calibration concerns the 10 minute mean wind speed measurements. The comparison of the lidar measurements of the wind direction with that from wind vanes...

  14. Calibration of ground-based Lidar instrument WLS7-150

    DEFF Research Database (Denmark)

    Yordanova, Ginka; Gómez Arranz, Paula

    This report presents the result of the lidar calibration performed for the given WLS7 Windcube at DTU’s test site for large wind turbines at Høvsøre, Denmark. Calibration is here understood as the establishment of a relation between the reference wind speed measurements with measurement uncertain......This report presents the result of the lidar calibration performed for the given WLS7 Windcube at DTU’s test site for large wind turbines at Høvsøre, Denmark. Calibration is here understood as the establishment of a relation between the reference wind speed measurements with measurement...... uncertainties provided by measurement standard and corresponding lidar wind speed indications with associated measurement uncertainties. The lidar calibration concerns the 10 minute mean wind speed measurements. The comparison of the lidar measurements of the wind direction with that from wind vanes...

  15. Calibration of ground-based lidar instrument WLS7-204

    DEFF Research Database (Denmark)

    Gómez Arranz, Paula; Courtney, Michael

    This report presents the result of the lidar calibration performed for the given WLS7 Windcube at DTU’s test site for large wind turbine at Høvsøre, Denmark. Calibration is here understood as the establishment of a relation between the reference wind speed measurements with measurement uncertaint......This report presents the result of the lidar calibration performed for the given WLS7 Windcube at DTU’s test site for large wind turbine at Høvsøre, Denmark. Calibration is here understood as the establishment of a relation between the reference wind speed measurements with measurement...... uncertainties provided by measurement standard and corresponding lidar wind speed indications with associated measurement uncertainties. The lidar calibration concerns the 10 minute mean wind speed measurements. The comparison of the lidar measurements of the wind direction with that from wind vanes...

  16. High-contrast imaging of ɛ Eridani with ground-based instruments

    Science.gov (United States)

    Mizuki, T.; Yamada, T.; Carson, J. C.; Kuzuhara, M.; Nakagawa, T.; Nishikawa, J.; Sitko, M. L.; Kudo, T.; Kusakabe, N.; Hashimoto, J.; Abe, L.; Brander, W.; Brandt, T. D.; Egner, S.; Feldt, M.; Goto, M.; Grady, C. A.; Guyon, O.; Hayano, Y.; Hayashi, M.; Hayashi, S. S.; Henning, T.; Hodapp, K. W.; Ishii, M.; Iye, M.; Janson, M.; Kandori, R.; Knapp, G. R.; Kwon, J.; Matsuo, T.; McElwain, M. W.; Miyama, S.; Morino, J.; Moro-Martin, A.; Nishimura, T.; Pyo, T.; Serabyn, E.; Suenaga, T.; Suto, H.; Suzuki, R.; Takahashi, Y. H.; Takami, M.; Takato, N.; Terada, H.; Thalmann, C.; Turner, E. L.; Watanabe, M.; Wisniewski, J.; Takami, H.; Usuda, T.; Tamura, M.

    2016-11-01

    ɛ Eridani is one of the nearest solar-type stars. Its proximity and relatively young age allow high-contrast imaging observations to achieve sensitivities to planets at narrow separations down to an inner radius of 5 AU. Previous observational studies of the system report a dust disk with asymmetric morphology as well as a giant planet with large orbital eccentricity, which may require another massive companion to induce the peculiar morphology and to enhance the large orbital eccentricity. In this paper, we report results from deep high-contrastimaging observations to detect the previously reported planet and search for other unseen less massive companions with Subaru/HiCIAO, Gemini-South/NICI, and VLT/NACO. No positive detection was made, but high-contrast measurements with the CH4S narrow-band filter of HiCIAO achieved sensitivities at 14.7 mag differential magnitude level, at an angular separation of 1.0″. In terms of planetary mass, as determined by cooling evolutionary models, the highest sensitivities were achieved by the Lp broad-band filter of NACO, resulting in sensitivities corresponding to 1.8, 2.8, and 4.5 Mjup at the projected separation of 3 AU, if 200, 400, and 800 Myr is assumed for the age of the system, respectively. We also discuss origins of the dust disk from the detection sensitivity in the planetary mass and find that a less massive eccentric planet is preferred for disk stirring, which is consistent with the orbital parameters of ɛ Eri b claimed from the previous long-term radial velocity monitoring.

  17. Test of ground-based Lidar instrument WLS200S-11

    DEFF Research Database (Denmark)

    Gómez Arranz, Paula

    This report presents the result of the test performed for the given Windcube at DTU’s test site for large wind turbine at Høvsøre, Denmark. The test aims at establishing a relation between the reference wind measurements and corresponding lidar wind indications, and evaluating a set of quality...

  18. Calibration of ground-based Lidar instrument WLS866-4

    DEFF Research Database (Denmark)

    Yordanova, Ginka; Gómez Arranz, Paula

    This report presents the result of the lidar calibration performed for the given WLS7 Windcube at DTU’s test site for large wind turbines at Høvsøre, Denmark. Calibration is here understood as the establishment of a relation between the reference wind speed measurements with measurement uncertain......This report presents the result of the lidar calibration performed for the given WLS7 Windcube at DTU’s test site for large wind turbines at Høvsøre, Denmark. Calibration is here understood as the establishment of a relation between the reference wind speed measurements with measurement...... uncertainties provided by measurement standard and corresponding lidar wind speed indications with associated measurement uncertainties. The lidar calibration concerns the 10 minute mean wind speed measurements. The comparison of the lidar measurements of the wind direction with that from wind vanes...

  19. Calibration of ground-based Lidar instrument WLS7-343

    DEFF Research Database (Denmark)

    Yordanova, Ginka; Gómez Arranz, Paula

    This report presents the result of the lidar calibration performed for the given WLS7 Windcube at DTU’s test site for large wind turbines at Høvsøre, Denmark. Calibration is here understood as the establishment of a relation between the reference wind speed measurements with measurement uncertain......This report presents the result of the lidar calibration performed for the given WLS7 Windcube at DTU’s test site for large wind turbines at Høvsøre, Denmark. Calibration is here understood as the establishment of a relation between the reference wind speed measurements with measurement...... uncertainties provided by measurement standard and corresponding lidar wind speed indications with associated measurement uncertainties. The lidar calibration concerns the 10 minute mean wind speed measurements. The comparison of the lidar measurements of the wind direction with that from wind vanes...

  20. Calibration of ground-based Lidar instrument WLS7-377

    DEFF Research Database (Denmark)

    Yordanova, Ginka; Gómez Arranz, Paula

    This report presents the result of the lidar calibration performed for the given WLS7 Windcube at DTU’s test site for large wind turbines at Høvsøre, Denmark. Calibration is here understood as the establishment of a relation between the reference wind speed measurements with measurement uncertain......This report presents the result of the lidar calibration performed for the given WLS7 Windcube at DTU’s test site for large wind turbines at Høvsøre, Denmark. Calibration is here understood as the establishment of a relation between the reference wind speed measurements with measurement...... uncertainties provided by measurement standard and corresponding lidar wind speed indications with associated measurement uncertainties. The lidar calibration concerns the 10 minute mean wind speed measurements. The comparison of the lidar measurements of the wind direction with that from wind vanes...

  1. Calibration of ground-based Lidar instrument WLS7-219

    DEFF Research Database (Denmark)

    Yordanova, Ginka; Gómez Arranz, Paula

    This report presents the result of the lidar calibration performed for the given WLS7 Windcube at DTU’s test site for large wind turbines at Høvsøre, Denmark. Calibration is here understood as the establishment of a relation between the reference wind speed measurements with measurement uncertain......This report presents the result of the lidar calibration performed for the given WLS7 Windcube at DTU’s test site for large wind turbines at Høvsøre, Denmark. Calibration is here understood as the establishment of a relation between the reference wind speed measurements with measurement...... uncertainties provided by measurement standard and corresponding lidar wind speed indications with associated measurement uncertainties. The lidar calibration concerns the 10 minute mean wind speed measurements. The comparison of the lidar measurements of the wind direction with that from wind vanes...

  2. Calibration of ground-based lidar instrument WLS7-202

    DEFF Research Database (Denmark)

    Gómez Arranz, Paula; Courtney, Michael

    This report presents the result of the lidar calibration performed for the given WLS7 Windcube at DTU’s test site for large wind turbine at Høvsøre, Denmark. Calibration is here understood as the establishment of a relation between the reference wind speed measurements with measurement uncertaint......This report presents the result of the lidar calibration performed for the given WLS7 Windcube at DTU’s test site for large wind turbine at Høvsøre, Denmark. Calibration is here understood as the establishment of a relation between the reference wind speed measurements with measurement...... uncertainties provided by measurement standard and corresponding lidar wind speed indications with associated measurement uncertainties. The lidar calibration concerns the 10 minute mean wind speed measurements. The comparison of the lidar measurements of the wind direction with that from wind vanes...

  3. Calibration of ground-based Lidar instrument WLS866-3

    DEFF Research Database (Denmark)

    Yordanova, Ginka; Gómez Arranz, Paula

    This report presents the result of the lidar calibration performed for the given WLS7 Windcube at DTU’s test site for large wind turbines at Høvsøre, Denmark. Calibration is here understood as the establishment of a relation between the reference wind speed measurements with measurement uncertain......This report presents the result of the lidar calibration performed for the given WLS7 Windcube at DTU’s test site for large wind turbines at Høvsøre, Denmark. Calibration is here understood as the establishment of a relation between the reference wind speed measurements with measurement...... uncertainties provided by measurement standard and corresponding lidar wind speed indications with associated measurement uncertainties. The lidar calibration concerns the 10 minute mean wind speed measurements. The comparison of the lidar measurements of the wind direction with that from wind vanes...

  4. Calibration of ground-based Lidar instrument WLS866-9

    DEFF Research Database (Denmark)

    Yordanova, Ginka; Gómez Arranz, Paula

    This report presents the result of the lidar calibration performed for the given WLS7 Windcube at DTU’s test site for large wind turbines at Høvsøre, Denmark. Calibration is here understood as the establishment of a relation between the reference wind speed measurements with measurement uncertain......This report presents the result of the lidar calibration performed for the given WLS7 Windcube at DTU’s test site for large wind turbines at Høvsøre, Denmark. Calibration is here understood as the establishment of a relation between the reference wind speed measurements with measurement...... uncertainties provided by measurement standard and corresponding lidar wind speed indications with associated measurement uncertainties. The lidar calibration concerns the 10 minute mean wind speed measurements. The comparison of the lidar measurements of the wind direction with that from wind vanes...

  5. Calibration of ground-based lidar instrument WLS7-203

    DEFF Research Database (Denmark)

    Gómez Arranz, Paula; Courtney, Michael

    This report presents the result of the lidar calibration performed for the given WLS7 Windcube at DTU’s test site for large wind turbine at Høvsøre, Denmark. Calibration is here understood as the establishment of a relation between the reference wind speed measurements with measurement uncertaint......This report presents the result of the lidar calibration performed for the given WLS7 Windcube at DTU’s test site for large wind turbine at Høvsøre, Denmark. Calibration is here understood as the establishment of a relation between the reference wind speed measurements with measurement...... uncertainties provided by measurement standard and corresponding lidar wind speed indications with associated measurement uncertainties. The lidar calibration concerns the 10 minute mean wind speed measurements. The comparison of the lidar measurements of the wind direction with that from wind vanes...

  6. Calibration of ground-based lidar instrument WLS7-222

    DEFF Research Database (Denmark)

    Gómez Arranz, Paula; Wagner, Rozenn

    This report presents the result of the lidar calibration performed for the given WLS7 Windcube at DTU’s test site for large wind turbine at Høvsøre, Denmark. Calibration is here understood as the establishment of a relation between the reference wind speed measurements with measurement uncertaint......This report presents the result of the lidar calibration performed for the given WLS7 Windcube at DTU’s test site for large wind turbine at Høvsøre, Denmark. Calibration is here understood as the establishment of a relation between the reference wind speed measurements with measurement...... uncertainties provided by measurement standard and corresponding lidar wind speed indications with associated measurement uncertainties. The lidar calibration concerns the 10 minute mean wind speed measurements. The comparison of the lidar measurements of the wind direction with that from wind vanes...

  7. Calibration of ground-based Lidar instrument WLS7-9

    DEFF Research Database (Denmark)

    Yordanova, Ginka; Gómez Arranz, Paula

    This report presents the result of the lidar calibration performed for the given WLS7 Windcube at DTU’s test site for large wind turbines at Høvsøre, Denmark. Calibration is here understood as the establishment of a relation between the reference wind speed measurements with measurement uncertain......This report presents the result of the lidar calibration performed for the given WLS7 Windcube at DTU’s test site for large wind turbines at Høvsøre, Denmark. Calibration is here understood as the establishment of a relation between the reference wind speed measurements with measurement...... uncertainties provided by measurement standard and corresponding lidar wind speed indications with associated measurement uncertainties. The lidar calibration concerns the 10 minute mean wind speed measurements. The comparison of the lidar measurements of the wind direction with that from wind vanes...

  8. Calibration of ground-based lidar instrument WLS7-204

    DEFF Research Database (Denmark)

    Gómez Arranz, Paula; Courtney, Michael

    This report presents the result of the lidar calibration performed for the given WLS7 Windcube at DTU’s test site for large wind turbine at Høvsøre, Denmark. Calibration is here understood as the establishment of a relation between the reference wind speed measurements with measurement uncertaint......This report presents the result of the lidar calibration performed for the given WLS7 Windcube at DTU’s test site for large wind turbine at Høvsøre, Denmark. Calibration is here understood as the establishment of a relation between the reference wind speed measurements with measurement...... uncertainties provided by measurement standard and corresponding lidar wind speed indications with associated measurement uncertainties. The lidar calibration concerns the 10 minute mean wind speed measurements. The comparison of the lidar measurements of the wind direction with that from wind vanes...

  9. Calibration of ground-based Lidar instrument WLS7-269

    DEFF Research Database (Denmark)

    Gómez Arranz, Paula; Wagner, Rozenn

    This report presents the result of the lidar calibration performed for the given WLS7 Windcube at DTU’s test site for large wind turbines at Høvsøre, Denmark. Calibration is here understood as the establishment of a relation between the reference wind speed measurements with measurement uncertain......This report presents the result of the lidar calibration performed for the given WLS7 Windcube at DTU’s test site for large wind turbines at Høvsøre, Denmark. Calibration is here understood as the establishment of a relation between the reference wind speed measurements with measurement...... uncertainties provided by measurement standard and corresponding lidar wind speed indications with associated measurement uncertainties. The lidar calibration concerns the 10 minute mean wind speed measurements. The comparison of the lidar measurements of the wind direction with that from wind vanes...

  10. [Instrument to collect data for critical patients based on the theory of basic human needs].

    Science.gov (United States)

    Bordinhão, Rosaura Costa; Almeida, Miriam de Abreu

    2012-06-01

    This is an exploratory study based on qualitative approach that aimed to collectively construct an instrument to collect data for patients in the Intensive Care Unit (ICU), based on the Theory of Basic Human Needs (NHB). Data collection was through a focus group with four nurses from the ICU and four residents from the Nursing-Health Integrated Residency (RIS) program in seven meetings in 2009. The discussions produced in each session were analyzed as recommended by Horta. The instrument was divided into seven groups and 17 subgroups of needs. After testing and suggestions from participants, we elaborated the final version of the instrument and a guidance manualfor completing it, according to the need expressed by the group. Validation of the instrument and the manual and inclusion of teaching of the nursing process in the RIS activity program are suggested.

  11. Ground-based lidar and microwave radiometry synergy for high vertical resolution absolute humidity profiling

    Science.gov (United States)

    Barrera-Verdejo, María; Crewell, Susanne; Löhnert, Ulrich; Orlandi, Emiliano; Di Girolamo, Paolo

    2016-08-01

    Continuous monitoring of atmospheric humidity profiles is important for many applications, e.g., assessment of atmospheric stability and cloud formation. Nowadays there are a wide variety of ground-based sensors for atmospheric humidity profiling. Unfortunately there is no single instrument able to provide a measurement with complete vertical coverage, high vertical and temporal resolution and good performance under all weather conditions, simultaneously. For example, Raman lidar (RL) measurements can provide water vapor with a high vertical resolution, albeit with limited vertical coverage, due to sunlight contamination and the presence of clouds. Microwave radiometers (MWRs) receive water vapor information throughout the troposphere, though their vertical resolution is poor. In this work, we present an MWR and RL system synergy, which aims to overcome the specific sensor limitations. The retrieval algorithm combining these two instruments is an optimal estimation method (OEM), which allows for an uncertainty analysis of the retrieved profiles. The OEM combines measurements and a priori information, taking the uncertainty of both into account. The measurement vector consists of a set of MWR brightness temperatures and RL water vapor profiles. The method is applied to a 2-month field campaign around Jülich (Germany), focusing on clear sky periods. Different experiments are performed to analyze the improvements achieved via the synergy compared to the individual retrievals. When applying the combined retrieval, on average the theoretically determined absolute humidity uncertainty is reduced above the last usable lidar range by a factor of ˜ 2 with respect to the case where only RL measurements are used. The analysis in terms of degrees of freedom per signal reveal that most information is gained above the usable lidar range, especially important during daytime when the lidar vertical coverage is limited. The retrieved profiles are further evaluated using

  12. Determination of Cloud Thermodynamic Phase with Ground Based, Polarimetrically Sensitive, Passive Sky Radiometers

    Science.gov (United States)

    Knobelspiesse, K. D.; van Diedenhoven, B.; Marshak, A.; Dunagan, S. E.; Holben, B. N.; Slutsker, I.

    2015-12-01

    When observed from the ground, optically thick clouds minimally polarize light, while the linear polarization direction (angle) of optically thin clouds contains information about thermodynamic phase. For instruments such at the Cimel radiometers that comprise the AErosol RObotic NEtwork (AERONET), these properties can also be exploited to aid cloud optical property retrievals. Using vector radiative transfer simulations, we explore the conditions most favorable to cloud thermodynamic phase determination, then test with actual AERONET data. Results indicate that this technique may be appropriate for some, but not all, conditions, and motivate a deeper investigation about the polarization direction measurement capability of Cimel instruments, which to date have been primarily used to determine degree of polarization. Recent work explores these measurement issues using a newly installed instrument at the NASA Ames Research Center in Moffett Field, California.

  13. Space- and ground-based particle physics meet at CERN

    CERN Document Server

    CERN Bulletin

    2012-01-01

    The fourth international conference on Particle and Fundamental Physics in Space (SpacePart12) will take place at CERN from 5 to 7 November. The conference will bring together scientists working on particle and fundamental physics in space and on ground, as well as space policy makers from around the world.   One hundred years after Victor Hess discovered cosmic rays using hot air balloons, the experimental study of particle and fundamental physics is still being pursued today with extremely sophisticated techniques: on the ground, with state-of-the-art accelerators like the LHC; and in space, with powerful observatories that probe, with amazing accuracy, the various forms of cosmic radiation, charged and neutral, which are messengers of the most extreme conditions of matter and energy. SpacePart12 will be the opportunity for participants to exchange views on the progress of space-related science and technology programmes in the field of particle and fundamental physics in space. SpacePar...

  14. Ground-based Fourier transform infrared spectroscopy in central Mexico

    Science.gov (United States)

    Plaza, Eddy; Stremme, Wolfgang; Bezanilla, Alejandro; Baylon, Jorge; Grutter, Michel; Blumenstock, Thomas; Hase, Frank

    2014-05-01

    Altzomoni is a high altitude station in central Mexico (19.12 N, 98.65 W, 4000 m a.s.l.) for continuous measurements of various atmospheric parameters. It is located within the Izta-Popo National Park and is operated remotely from the UNAM campus. Since May 2012, high resolution solar absorption spectra have been recorded from this site using a FTIR from Bruker (HR120/5) equipped with MCT, InSb and InGaAs detectors and various optical filters. In this contribution we present a detailed description of the measurement site and the instrumental set-up including a record of the instrumental line-shapes (modulation efficiency and phase error) obtained from cell measurements and analyzed with the LINEFIT code. A preliminary analysis of almost two years of spectra recorded at the Altzomoni site resulting in profile retrievals of four NDACC gases O3, CO, HF and HCl is presented. The retrieval code PROFFIT is used and the Averaging Kernels and an error analysis are used to describe the quality of the measurements. The annual cycles in the time series of O3 and CO are presented and discussed, as well as some examples of anomalies due to volcanic gas emissions of HF and HCl are shown. The presented work is part of an effort to certify this station as part of the NDACC international network.

  15. [Design and implementation of medical instrument standard information retrieval system based on APS.NET].

    Science.gov (United States)

    Yu, Kaijun

    2010-07-01

    This paper Analys the design goals of Medical Instrumentation standard information retrieval system. Based on the B /S structure,we established a medical instrumentation standard retrieval system with ASP.NET C # programming language, IIS f Web server, SQL Server 2000 database, in the. NET environment. The paper also Introduces the system structure, retrieval system modules, system development environment and detailed design of the system.

  16. Measuring health literacy regarding infectious respiratory diseases: a new skills-based instrument.

    Directory of Open Access Journals (Sweden)

    Xinying Sun

    Full Text Available BACKGROUND: There is no special instrument to measure skills-based health literacy where it concerns infectious respiratory diseases. This study aimed to explore and evaluate a new skills-based instrument on health literacy regarding respiratory infectious diseases. METHODS: This instrument was designed to measure not only an individual's reading and numeracy ability, but also their oral communication ability and their ability to use the internet to seek information. Sixteen stimuli materials were selected to enable measurement of the skills, which were sourced from the WHO, China CDC, and Chinese Center of Health Education. The information involved the distribution of epidemics, immunization programs, early symptoms, means of disease prevention, individual's preventative behavior, use of medications and thermometers, treatment plans and the location of hospitals. Multi-stage stratified cluster sampling was employed to collect participants. Psychometric properties were used to evaluate the reliability and validity of the instrument. RESULTS: The overall degree of difficulty and discrimination of the instrument were 0.693 and 0.482 respectively. The instrument demonstrated good internal consistency reliability with a Cronbach's alpha of 0.864. As for validity, six factors were extracted from 30 items, which together explained 47.3% of the instrument's variance. And based on confirmatory factor analysis, the items were grouped into five subscales representing prose, document, quantitative, oral and internet based information seeking skills (χ(2 = 9.200, P>0.05, GFI = 0.998, TLI = 0.988, AGFI = 0.992, RMSEA = 0.028. CONCLUSION: The new instrument has good reliability and validity, and it could be used to assess the health literacy regarding respiratory infectious disease status of different groups.

  17. Electromechanical instrument collaborative sharing system based on A/S mode

    Institute of Scientific and Technical Information of China (English)

    ZHANG Ying; YANG Yu; XIE Qiu; YUAN Qianbin; LIU Fei

    2006-01-01

    In this paper, we put forward a collaborative mode based on A/S mode to solve existing problems in the process of developing electromechanical instrument collaborative sharing system (EICSS). The mode architecture, working pattern and development flow of this system were described. The prototype system developed was applied to Lambda 900 Spectrometer in Chongqing University to realize electromechanical instrument networked sharing, and demonstrated desirable expansibility and felxibility to satisfy diverse demands of customers.

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

    Directory of Open Access Journals (Sweden)

    E. Hirsch

    2011-01-01

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

  19. Ground-Based Lidar Measurements During the CALIPSO and Twilight Zone (CATZ) Campaign

    Science.gov (United States)

    Berkoff, Timothy; Qian, Li; Kleidman, Richard; Stewart, Sebastian; Welton, Ellsworth; Li, Zhu; Holbem, Brent

    2008-01-01

    The CALIPSO and Twilight Zone (CATZ) field campaign was carried out between June 26th and August 29th of 2007 in the multi-state Maryland-Virginia-Pennsylvania region of the U.S. to study aerosol properties and cloud-aerosol interactions during overpasses of the CALIPSO satellite. Field work was conducted on selected days when CALIPSO ground tracks occurred in the region. Ground-based measurements included data from multiple Cimel sunphotometers that were placed at intervals along a segment of the CALIPSO ground-track. These measurements provided sky radiance and AOD measurements to enable joints inversions and comparisons with CALIPSO retrievals. As part of this activity, four ground-based lidars provided backscatter measurements (at 523 nm) in the region. Lidars at University of Maryland Baltimore County (Catonsville, MD) and Goddard Space Flight Center (Greenbelt, MD) provided continuous data during the campaign, while two micro-pulse lidar (MPL) systems were temporarily stationed at various field locations directly on CALIPSO ground-tracks. As a result, thirteen on-track ground-based lidar observations were obtained from eight different locations in the region. In some cases, nighttime CALIPSO coincident measurements were also obtained. In most studies reported to date, ground-based lidar validation efforts for CALIPSO rely on systems that are at fixed locations some distance away from the satellite ground-track. The CATZ ground-based lidar data provide an opportunity to examine vertical structure properties of aerosols and clouds both on and off-track simultaneously during a CALIPSO overpass. A table of available ground-based lidar measurements during this campaign will be presented, along with example backscatter imagery for a number of coincident cases with CALIPSO. Results indicate that even for a ground-based measurements directly on-track, comparisons can still pose a challenge due to the differing spatio-temporal properties of the ground and satellite

  20. Improving the detection of explosive hazards with LIDAR-based ground plane estimation

    Science.gov (United States)

    Buck, A.; Keller, J. M.; Popescu, M.

    2016-05-01

    Three-dimensional point clouds generated by LIDAR offer the potential to build a more complete understanding of the environment in front of a moving vehicle. In particular, LIDAR data facilitates the development of a non-parametric ground plane model that can filter target predictions from other sensors into above-ground and below-ground sets. This allows for improved detection performance when, for example, a system designed to locate above-ground targets considers only the set of above-ground predictions. In this paper, we apply LIDAR-based ground plane filtering to a forward looking ground penetrating radar (FLGPR) sensor system and a side looking synthetic aperture acoustic (SAA) sensor system designed to detect explosive hazards along the side of a road. Additionally, we consider the value of the visual magnitude of the LIDAR return as a feature for identifying anomalies. The predictions from these sensors are evaluated independently with and without ground plane filtering and then fused to produce a combined prediction confidence. Sensor fusion is accomplished by interpolating the confidence scores of each sensor along the ground plane model to create a combined confidence vector at specified points in the environment. The methods are tested along an unpaved desert road at an arid U.S. Army test site.

  1. Microcontroller based ground weapon control system(Short Communication

    Directory of Open Access Journals (Sweden)

    M. Sankar Kishore

    2001-10-01

    Full Text Available Armoured vehicles and tanks generally consist of high resolution optical (both infrared and visible and display systems for recognition and identification of the targets. Different weapons/articles to engage the targets may be present. A fire control system (FCS controls all the above systems, monitors the status of the articles present and passes the information to the display system. Depending upon the health and availability of the articles, the FCS selects and fires the articles. Design and development of ground control unit which is the heart of the FCS, both in hardware and software, has been emphasised. The system has been developed using microcontroller and software developed in ASM 51 language. The system also has a facility to test all the systems and articles as initial power on condition. From the safety point of view, software and hardware interlocks have been provided in the critical operations, like firing sequence. "

  2. Subtropical and Polar Cirrus Clouds Characterized by Ground-Based Lidars and CALIPSO/CALIOP Observations

    Directory of Open Access Journals (Sweden)

    Córdoba-Jabonero Carmen

    2016-01-01

    Full Text Available Cirrus clouds are product of weather processes, and then their occurrence and macrophysical/optical properties can vary significantly over different regions of the world. Lidars can provide height-resolved measurements with a relatively good both vertical and temporal resolutions, making them the most suitable instrumentation for high-cloud observations. The aim of this work is to show the potential of lidar observations on Cirrus clouds detection in combination with a recently proposed methodology to retrieve the Cirrus clouds macrophysical and optical features. In this sense, a few case studies of cirrus clouds observed at both subtropical and polar latitudes are examined and compared to CALIPSO/CALIOP observations. Lidar measurements are carried out in two stations: the Metropolitan city of Sao Paulo (MSP, Brazil, 23.3°S 46.4°W, located at subtropical latitudes, and the Belgrano II base (BEL, Argentina, 78ºS 35ºW in the Antarctic continent. Optical (COD-cloud optical depth and LR-Lidar Ratio and macrophysical (top/base heights and thickness properties of both the subtropical and polar cirrus clouds are reported. In general, subtropical Cirrus clouds present lower LR values and are found at higher altitudes than those detected at polar latitudes. In general, Cirrus clouds are detected at similar altitudes by CALIOP. However, a poor agreement is achieved in the LR retrieved between ground-based lidars and space-borne CALIOP measurements, likely due to the use of a fixed (or low-variable LR value in CALIOP inversion procedures.

  3. Subtropical and Polar Cirrus Clouds Characterized by Ground-Based Lidars and CALIPSO/CALIOP Observations

    Science.gov (United States)

    Córdoba-Jabonero, Carmen; Lopes, Fabio J. S.; Landulfo, Eduardo; Ochoa, Héctor; Gil-Ojeda, Manuel

    2016-06-01

    Cirrus clouds are product of weather processes, and then their occurrence and macrophysical/optical properties can vary significantly over different regions of the world. Lidars can provide height-resolved measurements with a relatively good both vertical and temporal resolutions, making them the most suitable instrumentation for high-cloud observations. The aim of this work is to show the potential of lidar observations on Cirrus clouds detection in combination with a recently proposed methodology to retrieve the Cirrus clouds macrophysical and optical features. In this sense, a few case studies of cirrus clouds observed at both subtropical and polar latitudes are examined and compared to CALIPSO/CALIOP observations. Lidar measurements are carried out in two stations: the Metropolitan city of Sao Paulo (MSP, Brazil, 23.3°S 46.4°W), located at subtropical latitudes, and the Belgrano II base (BEL, Argentina, 78ºS 35ºW) in the Antarctic continent. Optical (COD-cloud optical depth and LR-Lidar Ratio) and macrophysical (top/base heights and thickness) properties of both the subtropical and polar cirrus clouds are reported. In general, subtropical Cirrus clouds present lower LR values and are found at higher altitudes than those detected at polar latitudes. In general, Cirrus clouds are detected at similar altitudes by CALIOP. However, a poor agreement is achieved in the LR retrieved between ground-based lidars and space-borne CALIOP measurements, likely due to the use of a fixed (or low-variable) LR value in CALIOP inversion procedures.

  4. Ground-based aerosol characterization during the South American Biomass Burning Analysis (SAMBBA) field experiment

    Science.gov (United States)

    Brito, J.; Rizzo, L. V.; Morgan, W. T.; Coe, H.; Johnson, B.; Haywood, J.; Longo, K.; Freitas, S.; Andreae, M. O.; Artaxo, P.

    2014-11-01

    This paper investigates the physical and chemical characteristics of aerosols at ground level at a site heavily impacted by biomass burning. The site is located near Porto Velho, Rondônia, in the southwestern part of the Brazilian Amazon rainforest, and was selected for the deployment of a large suite of instruments, among them an Aerosol Chemical Speciation Monitor. Our measurements were made during the South American Biomass Burning Analysis (SAMBBA) field experiment, which consisted of a combination of aircraft and ground-based measurements over Brazil, aimed to investigate the impacts of biomass burning emissions on climate, air quality, and numerical weather prediction over South America. The campaign took place during the dry season and the transition to the wet season in September/October 2012. During most of the campaign, the site was impacted by regional biomass burning pollution (average CO mixing ratio of 0.6 ppm), occasionally superimposed by intense (up to 2 ppm of CO), freshly emitted biomass burning plumes. Aerosol number concentrations ranged from ~1000 cm-3 to peaks of up to 35 000 cm-3 (during biomass burning (BB) events, corresponding to an average submicron mass mean concentrations of 13.7 μg m-3 and peak concentrations close to 100 μg m-3. Organic aerosol strongly dominated the submicron non-refractory composition, with an average concentration of 11.4 μg m-3. The inorganic species, NH4, SO4, NO3, and Cl, were observed, on average, at concentrations of 0.44, 0.34, 0.19, and 0.01 μg m-3, respectively. Equivalent black carbon (BCe) ranged from 0.2 to 5.5 μg m-3, with an average concentration of 1.3 μg m-3. During BB peaks, organics accounted for over 90% of total mass (submicron non-refractory plus BCe), among the highest values described in the literature. We examined the ageing of biomass burning organic aerosol (BBOA) using the changes in the H : C and O : C ratios, and found that throughout most of the aerosol processing (O : C ≅ 0

  5. Ground based aerosol characterization during the South American Biomass Burning Analysis (SAMBBA field experiment

    Directory of Open Access Journals (Sweden)

    J. Brito

    2014-05-01

    Full Text Available This paper investigates the physical and chemical characteristics of aerosols at ground level at a site heavily impacted by biomass burning. The site is located near Porto Velho, Rondônia, in the Southwestern part of the Brazilian Amazon forest, and was selected for the deployment of a large suite of instruments, among them an Aerosol Chemical Speciation Monitor. Our measurements were made during the South American Biomass Burning Analysis (SAMBBA field experiment, which consisted of a combination of aircraft and ground based measurements over Brazil, aiming to investigate the impacts of biomass burning emissions on climate, air quality, and numerical weather prediction over South America. The campaign took place during the dry season and the transition to the wet season in September/October 2012. During most of the campaign, the site was impacted by regional biomass burning pollution (average CO mixing ratio of 0.6 ppm, occasionally superimposed by intense (up to 2 ppm of CO, freshly emitted biomass burning plumes. Aerosol number concentrations ranged from ∼1000 cm−3 to peaks of up to 35 000 cm−3 during biomass burning (BB events, corresponding to an average submicron mass mean concentrations of 13.7 μg m−3 and peak concentrations close to 100 μg m−3. Organic aerosol strongly dominated the submicron non-refractory composition, with an average concentration of 11.4 μg m−3. The inorganic species, NH4, SO4, NO3, and Cl, were observed on average at concentrations of 0.44, 0.34, 0.19, and 0.01 μg m−3, respectively. Equivalent Black Carbon (BCe ranged from 0.2 to 5.5 μg m−3, with an average concentration of 1.3 μg m−3. During BB peaks, organics accounted for over 90% of total mass (submicron non-refractory plus BCe, among the highest values described in the literature. We examined the ageing of Biomass Burning Organic Aerosol (BBOA using the changes in the H : C and O : C ratios, and found that throughout most of the aerosol

  6. NASA's Newest Orbital Debris Ground-based Telescope Assets: MCAT and UKIRT

    Science.gov (United States)

    Lederer, S. M.; Frith, J. M.; Pace, L. F.; Cowardin, H. M.; Cowardin, H. M.; Hickson, P.; Glesne, T.; Maeda, R.; Buckalew, B.; Nishimoto, D.; hide

    2014-01-01

    NASA's Orbital Debris Program Office (ODPO) will break ground on Ascension Island in 2014 to build the newest optical (0.30 - 1.06 micrometers) ground-based telescope asset dedicated to the study of orbital debris. The Meter Class Autonomous Telescope (MCAT) is a 1.3m optical telescope designed to track objects in orbits ranging from Low Earth Orbit (LEO) to Geosynchronous Earth Orbit (GEO). Ascension Island is located in the South Atlantic Ocean, offering longitudinal sky coverage not afforded by the Ground-based Electro-Optical Deep Space Surveillance (GEODSS) network. With a fast-tracking dome, a suite of visible wide-band filters, and a time-delay integration (TDI) capable camera, MCAT is capable of multiple observing modes ranging from tracking cataloged debris targets to surveying the overall debris environment. Access to the United Kingdom Infrared Telescope (UKIRT) will extend our spectral coverage into the near- (0.8-5 micrometers) and mid- to far-infrared (8-25 micrometers) regime. UKIRT is a 3.8m telescope located on Mauna Kea on the Big Island of Hawaii. At nearly 14,000-feet and above the atmospheric inversion layer, this is one of the premier astronomical sites in the world and is an ideal setting for an infrared telescope. An unprecedented one-third of this telescope's time has been allocated to collect orbital debris data for NASA's ODPO over a 2-year period. UKIRT has several instruments available to obtain low-resolution spectroscopy in both the near-IR and the mid/far-IR. Infrared spectroscopy is ideal for constraining the material types, albedos and sizes of debris targets, and potentially gaining insight into reddening effects caused by space weathering. In addition, UKIRT will be used to acquire broadband photometric imaging at GEO with the Wide Field Camera (WFCAM) for studying known objects of interest as well as collecting data in survey-mode to discover new targets. Results from the first stage of the debris campaign will be presented. The

  7. Mesoscale ionospheric electrodynamics of omega bands determined from ground-based electromagnetic and satellite optical observations

    Directory of Open Access Journals (Sweden)

    O. Amm

    2005-02-01

    Full Text Available We present ground-based electromagnetic data from the MIRACLE and BEAR networks and satellite optical observations from the UVI and PIXIE instruments on the Polar satellite of an omega band event over Northern Scandinavia on 26 June 1998, which occured close to the morning side edge of a substorm auroral bulge. Our analysis of the data concentrates on one omega band period from 03:18-03:27 UT, for which we use the method of characteristics combined with an analysis of the UVI and PIXIE data to derive a time series of instantaneous, solely data-based distributions of the mesoscale ionospheric electrodynamic parameters with a 1-min time resolution. In addition, the AMIE method is used to derive global Hall conductance patterns. Our results show that zonally alternating regions of enhanced ionospheric conductances ("tongues" up to ~60S and low conductance regions are associated with the omega bands. The tongues have a poleward extension of ~400km from their base and a zonal extension of ~380km. While they are moving coherently eastward with a velocity of ~770ms-1, the structures are not strictly stationary. The current system of the omega band can be described as a superposition of two parts: one consists of anticlockwise rotating Hall currents around the tongues, along with Pedersen currents, with a negative divergence in their centers. The sign of this system is reversing in the low conductance areas. It causes the characteristic ground magnetic signature. The second part consists of zonally aligned current wedges of westward flowing Hall currents and is mostly magnetically invisible below the ionosphere. This system dominates the field-aligned current (FAC pattern and causes alternating upward and downward FAC at the flanks of the tongues with maximum upward FAC of ~25µA m-2. The total FAC of ~2MA are comparable to the ones diverted inside a westward traveling surge. Throughout the event, the overwhelming part of the FAC

  8. RTTOV-gb - adapting the fast radiative transfer model RTTOV for the assimilation of ground-based microwave radiometer observations

    Science.gov (United States)

    De Angelis, Francesco; Cimini, Domenico; Hocking, James; Martinet, Pauline; Kneifel, Stefan

    2016-08-01

    Ground-based microwave radiometers (MWRs) offer a new capability to provide continuous observations of the atmospheric thermodynamic state in the planetary boundary layer. Thus, they are potential candidates to supplement radiosonde network and satellite data to improve numerical weather prediction (NWP) models through a variational assimilation of their data. However in order to assimilate MWR observations, a fast radiative transfer model is required and such a model is not currently available. This is necessary for going from the model state vector space to the observation space at every observation point. The fast radiative transfer model RTTOV is well accepted in the NWP community, though it was developed to simulate satellite observations only. In this work, the RTTOV code has been modified to allow for simulations of ground-based upward-looking microwave sensors. In addition, the tangent linear, adjoint, and K-modules of RTTOV have been adapted to provide Jacobians (i.e., the sensitivity of observations to the atmospheric thermodynamical state) for ground-based geometry. These modules are necessary for the fast minimization of the cost function in a variational assimilation scheme. The proposed ground-based version of RTTOV, called RTTOV-gb, has been validated against accurate and less time-efficient line-by-line radiative transfer models. In the frequency range commonly used for temperature and humidity profiling (22-60 GHz), root-mean-square brightness temperature differences are smaller than typical MWR uncertainties (˜ 0.5 K) at all channels used in this analysis. Brightness temperatures (TBs) computed with RTTOV-gb from radiosonde profiles have been compared with nearly simultaneous and co-located ground-based MWR observations. Differences between simulated and measured TBs are below 0.5 K for all channels except for the water vapor band, where most of the uncertainty comes from instrumental errors. The Jacobians calculated with the K-module of RTTOV

  9. A Reliability and Validity of an Instrument to Evaluate the School-Based Assessment System: A Pilot Study

    Science.gov (United States)

    Ghazali, Nor Hasnida Md

    2016-01-01

    A valid, reliable and practical instrument is needed to evaluate the implementation of the school-based assessment (SBA) system. The aim of this study is to develop and assess the validity and reliability of an instrument to measure the perception of teachers towards the SBA implementation in schools. The instrument is developed based on a…

  10. (Environmental investigation of ground water contamination at Wright-Patterson Air Force Base, Ohio)

    Energy Technology Data Exchange (ETDEWEB)

    1991-10-01

    This report presents information concerning field procedures employed during the monitoring, well construction, well purging, sampling, and well logging at the Wright-Patterson Air Force Base. Activities were conducted in an effort to evaluate ground water contamination.

  11. Informing hydrological models with ground-based time-lapse relative gravimetry: potential and limitations

    DEFF Research Database (Denmark)

    Bauer-Gottwein, Peter; Christiansen, Lars; Rosbjerg, Dan

    2011-01-01

    Coupled hydrogeophysical inversion emerges as an attractive option to improve the calibration and predictive capability of hydrological models. Recently, ground-based time-lapse relative gravity (TLRG) measurements have attracted increasing interest because there is a direct relationship between ...

  12. Changes in ground-based solar ultraviolet radiation during fire episodes: a case study

    CSIR Research Space (South Africa)

    Wright, CY

    2013-09-01

    Full Text Available about the relationship between fires and solar UVR without local high-quality column or ground-based ambient air pollution (particulate matter in particular) data; however, the threat to public health from fires was acknowledged....

  13. A CubeSat for Calibrating Ground-Based and Sub-Orbital Millimeter-Wave Polarimeters (CalSat)

    Science.gov (United States)

    Johnson, Bradley R.; Vourch, Clement J.; Drysdale, Timothy D.; Kalman, Andrew; Fujikawa, Steve; Keating, Brian; Kaufman, Jon

    2015-10-01

    We describe a low-cost, open-access, CubeSat-based calibration instrument that is designed to support ground-based and sub-orbital experiments searching for various polarization signals in the cosmic microwave background (CMB). All modern CMB polarization experiments require a robust calibration program that will allow the effects of instrument-induced signals to be mitigated during data analysis. A bright, compact and linearly polarized astrophysical source with polarization properties known to adequate precision does not exist. Therefore, we designed a space-based millimeter-wave calibration instrument, called CalSat, to serve as an open-access calibrator, and this paper describes the results of our design study. The calibration source on board CalSat is composed of five “tones” with one each at 47.1, 80.0, 140, 249 and 309GHz. The five tones we chose are well matched to (i) the observation windows in the atmospheric transmittance spectra, (ii) the spectral bands commonly used in polarimeters by the CMB community and (iii) the Amateur Satellite Service bands in the Table of Frequency Allocations used by the Federal Communications Commission. CalSat would be placed in a polar orbit allowing visibility from observatories in the Northern Hemisphere, such as Mauna Kea in Hawaii and Summit Station in Greenland, and the Southern Hemisphere, such as the Atacama Desert in Chile and the South Pole. CalSat also would be observable by balloon-borne instruments launched from a range of locations around the world. This global visibility makes CalSat the only source that can be observed by all terrestrial and sub-orbital observatories, thereby providing a universal standard that permits comparison between experiments using appreciably different measurement approaches.

  14. A CubeSat for Calibrating Ground-Based and Sub-Orbital Millimeter-Wave Polarimeters

    Science.gov (United States)

    Johnson, Bradley

    2016-06-01

    We describe a low-cost, open-access, CubeSat-based calibration instrument that is designed to support ground-based and sub-orbital experiments searching for various polarization signals in the cosmic microwave background (CMB). All modern CMB polarization experiments require a robust calibration program that will allow the effects of instrument-induced signals to be mitigated during data analysis. A bright, compact, and linearly polarized astrophysical source with polarization properties known to adequate precision does not exist. Therefore, we designed a space-based millimeter-wave calibration instrument, called CalSat, to serve as an open-access calibrator, and this paper describes the results of our design study. The calibration source on board CalSat is composed of five "tones'" with one each at 47.1, 80.0, 140, 249 and 309 GHz. The five tones we chose are well matched to (i) the observation windows in the atmospheric transmittance spectra, (ii) the spectral bands commonly used in polarimeters by the CMB community, and (iii) The Amateur Satellite Service bands in the Table of Frequency Allocations used by the Federal Communications Commission. CalSat will be placed in a polar orbit allowing visibility from observatories in the Northern Hemisphere, such as Mauna~Kea in Hawaii and Summit Station in Greenland, and the Southern Hemisphere, such as the Atacama Desert in Chile and the South Pole. CalSat also will be observable by balloon-borne instruments launched from a range of locations around the world. This global visibility makes CalSat the only source that can be observed by all terrestrial and sub-orbital observatories, thereby providing a universal standard that permits comparison between experiments using appreciably different measurement approaches.

  15. Initial Results from the DEEPWAVE Airborne and Ground-Based Measurement Program in New Zealand in 2014

    Science.gov (United States)

    Fritts, Dave; Smith, Ron; Taylor, Mike; Doyle, Jim; Eckermann, Steve; Dörnbrack, Andreas; Rapp, Markus; Williams, Biff; Bossert, Katrina; Pautet, Dominique

    2015-04-01

    The deep-propagating gravity wave experiment (DEEPWAVE) was performed on and over New Zealand, Tasmania, the Tasman Sea, and the Southern Ocean with core airborne measurements extending from 5 June to 21 July 2014 and supporting ground-based measurements beginning in late May and extending beyond the airborne component. DEEPWAVE employed two aircraft, the NSF/NCAR GV and the German DLR Falcon. The GV carried the standard flight-level instruments, dropsondes, and the Microwave Temperature Profiler (MTP). It also hosted new airborne lidar and imaging instruments built specifically to allow quantification of gravity waves (GWs) from sources at lower altitudes (e.g., orography, convection, jet streams, fronts, and secondary GW generation) throughout the stratosphere and into the mesosphere and lower thermosphere (MLT). The new GV lidars included a Rayleigh lidar measuring atmospheric density and temperature from ~20-60 km and a sodium resonance lidar measuring sodium density and temperature at ~75-100 km. An airborne Advanced Mesosphere Temperature Mapper (AMTM) was also developed for the GV, and together with additional IR "wing" cameras, imaged the OH airglow temperature and/or intensity fields extending ~900 km across the GV flight track. The DLR Falcon was equipped with its standard flight-level instruments and an aerosol Doppler lidar able to measure radial winds below the Falcon where aerosol backscatter was sufficient. Additional ground-based instruments included a 449 MHz boundary layer radar, balloons at multiple sites, two ground-based Rayleigh lidars, a second ground-based AMTM, a Fabry Perot interferometer measuring winds and temperatures at ~87 and 95 km, and a meteor radar measuring winds from ~80-100 km. DEEPWAVE performed 26 GV flights, 13 Falcon flights, and an extensive series of ground-based measurements whether or not the aircraft were flying. Together, these observed many diverse cases of GW forcing, propagation, refraction, and dissipation

  16. Development and first applications of an OH reactivity instrument based on the Comparative Reactivity Method

    Science.gov (United States)

    Dusanter, S.; Michoud, V.; Hansen, R. F.; Leonardis, T.; Locoge, N.; Stevens, P. S.; Blocquet, M.; Schoemaecker, C.; Fittschen, C. M.; Zannoni, N.; Gros, V.; Sarda Esteve, R.; Sinha, V.

    2015-12-01

    Assessing the oxidative capacity of the atmosphere is important to address fundamental issues related to both air quality and climate change. However, recent measurements of total OH reactivity have highlighted an incomplete understanding of the hydroxyl radical (OH) budget, the main oxidizing agent in the atmosphere. This context has led to the development of several techniques for measuring total OH reactivity to better constrain atmospheric chemistry. This presentation will review the development of an OH reactivity instrument developed at Mines Douai, France. This instrument, based on the Comparative Reactivity Method (CRM), has been carefully characterized in the laboratory and has been compared to other OH reactivity instruments during two different field campaigns. These studies will be summarized to show that CRM instruments can perform reliable measurements in urban and remote areas providing that a few measurement artefacts are well characterized and accounted for during field campaigns.

  17. Motion control solution for new PLC-based standard development platform for VLT instrument control systems

    Science.gov (United States)

    Popovic, D.; Brast, R.; Di Lieto, N.; Kiekebusch, M.; Knudstrup, J.; Lucuix, C.

    2014-07-01

    More than a decade ago, due to obsolescence issues, ESO initiated the design and implementation of a custom-made CANbus based motion controller (CAN-RMC) to provide, together with a tailor-made software library (motor library), the motion control capabilities for the VME platform needed for the second generation VLT/VLTI instruments. The CAN-RMC controller has been successfully used in a number of VLT instruments but it has high production costs compared to the commercial off-the-shelf (COTS) industrial solutions available on the market today. In the scope of the selection of a new PLC-based platform for the VLT instrument control systems, ESO has evaluated motion control solutions from the company Beckhoff. This paper presents the investigation, implementation and testing of the PLC/TwinCAT/EtherCAT motion controllers for DC and stepper motors and their adaptation and integration into the VLT instrumentation framework. It reports functional and performance test results for the most typical use cases of astronomical instruments like initialization sequences, tracking, switch position detections, backslash compensation, brake handling, etc. In addition, it gives an overview of the main features of TwinCAT NC/PTP, PLCopen MC, EtherCAT motion control terminals and the engineering tools like TwinCAT Scope that are integrated into the development environment and simplify software development, testing and commissioning of motorized instrument functions.

  18. Evidence-based management of deep wound infection after spinal instrumentation.

    Science.gov (United States)

    Lall, Rishi R; Wong, Albert P; Lall, Rohan R; Lawton, Cort D; Smith, Zachary A; Dahdaleh, Nader S

    2015-02-01

    In this study, evidence-based medicine is used to assess optimal surgical and medical management of patients with post-operative deep wound infection following spinal instrumentation. A computerized literature search of the PubMed database was performed. Twenty pertinent studies were identified. Studies were separated into publications addressing instrumentation retention versus removal and publications addressing antibiotic therapy regimen. The findings were classified based on level of evidence (I-III) and findings were summarized into evidentiary tables. No level I or II evidence was identified. With regards to surgical management, five studies support instrumentation retention in the setting of early deep infection. In contrast, for delayed infection, the evidence favors removal of instrumentation at the time of initial debridement. Surgeons should be aware that for deformity patients, even if solid fusion is observed, removal of instrumentation may be associated with significant loss of correction. A course of intravenous antibiotics followed by long-term oral suppressive therapy should be pursued if instrumentation is retained. A shorter treatment course may be appropriate if hardware is removed.

  19. System Identification and Automatic Mass Balancing of Ground-Based Three-Axis Spacecraft Simulator

    Science.gov (United States)

    2006-08-01

    System Identification and Automatic Mass Balancing of Ground-Based Three-Axis Spacecraft Simulator Jae-Jun Kim∗ and Brij N. Agrawal † Department of...TITLE AND SUBTITLE System Identification and Automatic Mass Balancing of Ground-Based Three-Axis Spacecraft Simulator 5a. CONTRACT NUMBER 5b...and Dynamics, Vol. 20, No. 4, July-August 1997, pp. 625-632. 6Schwartz, J. L. and Hall, C. D., “ System Identification of a Spherical Air-Bearing

  20. Calibration and evaluation of CCD spectroradiometers for ground-based and airborne measurements of spectral actinic flux densities

    Science.gov (United States)

    Bohn, Birger; Lohse, Insa

    2017-09-01

    The properties and performance of charge-coupled device (CCD) array spectroradiometers for the measurement of atmospheric spectral actinic flux densities (280-650 nm) and photolysis frequencies were investigated. These instruments are widely used in atmospheric research and are suitable for aircraft applications because of high time resolutions and high sensitivities in the UV range. The laboratory characterization included instrument-specific properties like the wavelength accuracy, dark signal, dark noise and signal-to-noise ratio (SNR). Spectral sensitivities were derived from measurements with spectral irradiance standards. The calibration procedure is described in detail, and a straightforward method to minimize the influence of stray light on spectral sensitivities is introduced. From instrument dark noise, minimum detection limits ≈ 1 × 1010 cm-2 s-1 nm-1 were derived for spectral actinic flux densities at wavelengths around 300 nm (1 s integration time). As a prerequisite for the determination of stray light under field conditions, atmospheric cutoff wavelengths were defined using radiative transfer calculations as a function of the solar zenith angle (SZA) and total ozone column (TOC). The recommended analysis of field data relies on these cutoff wavelengths and is also described in detail taking data from a research flight on HALO (High Altitude and Long Range Research Aircraft) as an example. An evaluation of field data was performed by ground-based comparisons with a double-monochromator-based, highly sensitive reference spectroradiometer. Spectral actinic flux densities were compared as well as photolysis frequencies j(NO2) and j(O1D), representing UV-A and UV-B ranges, respectively. The spectra expectedly revealed increased daytime levels of stray-light-induced signals and noise below atmospheric cutoff wavelengths. The influence of instrument noise and stray-light-induced noise was found to be insignificant for j(NO2) and rather limited for j(O1D

  1. Metrology of ground-based satellite validation: co-location mismatch and smoothing issues of total ozone comparisons

    Directory of Open Access Journals (Sweden)

    T. Verhoelst

    2015-12-01

    Full Text Available Comparisons with ground-based correlative measurements constitute a key component in the validation of satellite data on atmospheric composition. The error budget of these comparisons contains not only the measurement errors but also several terms related to differences in sampling and smoothing of the inhomogeneous and variable atmospheric field. A versatile system for Observing System Simulation Experiments (OSSEs, named OSSSMOSE, is used here to quantify these terms. Based on the application of pragmatic observation operators onto high-resolution atmospheric fields, it allows a simulation of each individual measurement, and consequently, also of the differences to be expected from spatial and temporal field variations between both measurements making up a comparison pair. As a topical case study, the system is used to evaluate the error budget of total ozone column (TOC comparisons between GOME-type direct fitting (GODFITv3 satellite retrievals from GOME/ERS2, SCIAMACHY/Envisat, and GOME-2/MetOp-A, and ground-based direct-sun and zenith–sky reference measurements such as those from Dobsons, Brewers, and zenith-scattered light (ZSL-DOAS instruments, respectively. In particular, the focus is placed on the GODFITv3 reprocessed GOME-2A data record vs. the ground-based instruments contributing to the Network for the Detection of Atmospheric Composition Change (NDACC. The simulations are found to reproduce the actual measurements almost to within the measurement uncertainties, confirming that the OSSE approach and its technical implementation are appropriate. This work reveals that many features of the comparison spread and median difference can be understood as due to metrological differences, even when using strict co-location criteria. In particular, sampling difference errors exceed measurement uncertainties regularly at most mid- and high-latitude stations, with values up to 10 % and more in extreme cases. Smoothing difference errors only

  2. Metrology of ground-based satellite validation: co-location mismatch and smoothing issues of total ozone comparisons

    Science.gov (United States)

    Verhoelst, T.; Granville, J.; Hendrick, F.; Köhler, U.; Lerot, C.; Pommereau, J.-P.; Redondas, A.; Van Roozendael, M.; Lambert, J.-C.

    2015-12-01

    Comparisons with ground-based correlative measurements constitute a key component in the validation of satellite data on atmospheric composition. The error budget of these comparisons contains not only the measurement errors but also several terms related to differences in sampling and smoothing of the inhomogeneous and variable atmospheric field. A versatile system for Observing System Simulation Experiments (OSSEs), named OSSSMOSE, is used here to quantify these terms. Based on the application of pragmatic observation operators onto high-resolution atmospheric fields, it allows a simulation of each individual measurement, and consequently, also of the differences to be expected from spatial and temporal field variations between both measurements making up a comparison pair. As a topical case study, the system is used to evaluate the error budget of total ozone column (TOC) comparisons between GOME-type direct fitting (GODFITv3) satellite retrievals from GOME/ERS2, SCIAMACHY/Envisat, and GOME-2/MetOp-A, and ground-based direct-sun and zenith-sky reference measurements such as those from Dobsons, Brewers, and zenith-scattered light (ZSL-)DOAS instruments, respectively. In particular, the focus is placed on the GODFITv3 reprocessed GOME-2A data record vs. the ground-based instruments contributing to the Network for the Detection of Atmospheric Composition Change (NDACC). The simulations are found to reproduce the actual measurements almost to within the measurement uncertainties, confirming that the OSSE approach and its technical implementation are appropriate. This work reveals that many features of the comparison spread and median difference can be understood as due to metrological differences, even when using strict co-location criteria. In particular, sampling difference errors exceed measurement uncertainties regularly at most mid- and high-latitude stations, with values up to 10 % and more in extreme cases. Smoothing difference errors only play a role in the

  3. Evaluation of tropospheric and stratospheric ozone trends over Western Europe from ground-based FTIR network observations

    Directory of Open Access Journals (Sweden)

    C. Vigouroux

    2008-12-01

    Full Text Available Within the European project UFTIR (Time series of Upper Free Troposphere observations from an European ground-based FTIR network, six ground-based stations in Western Europe, from 79° N to 28° N, all equipped with Fourier Transform infrared (FTIR instruments and part of the Network for the Detection of Atmospheric Composition Change (NDACC, have joined their efforts to evaluate the trends of several direct and indirect greenhouse gases over the period 1995–2004. The retrievals of CO, CH4, C2H6, N2O, CHClF2, and O3 have been optimized. Using the optimal estimation method, some vertical information can be obtained in addition to total column amounts. A bootstrap resampling method has been implemented to determine annual partial and total column trends for the target gases. The present work focuses on the ozone results. The retrieved time series of partial and total ozone columns are validated with ground-based correlative data (Brewer, Dobson, UV-Vis, ozonesondes, and Lidar. The observed total column ozone trends are in agreement with previous studies: 1 no total column ozone trend is seen at the lowest latitude station Izaña (28° N; 2 slightly positive total column trends are seen at the two mid-latitude stations Zugspitze and Jungfraujoch (47° N, only one of them being significant; 3 the highest latitude stations Harestua (60° N, Kiruna (68° N and Ny-Ålesund (79° N show significant positive total column trends. Following the vertical information contained in the ozone FTIR retrievals, we provide partial columns trends for the layers: ground-10 km, 10–18 km, 18–27 km, and 27–42 km, which helps to distinguish the contributions from dynamical and chemical changes on the total column ozone trends. We obtain no statistically significant trends in the ground-10 km layer for five out of the six ground-based stations. We find significant positive trends for the lowermost

  4. Development and characterization of the CU ground MAX-DOAS instrument: lowering RMS noise and first measurements of BrO, IO, and CHOCHO near Pensacola, FL

    Science.gov (United States)

    Coburn, S.; Dix, B.; Sinreich, R.; Volkamer, R.

    2011-01-01

    We designed and assembled the University of Colorado Ground Multi AXis Differential Optical Absorption Spectroscopy (CU GMAX-DOAS) instrument to retrieve bromine oxide (BrO), iodine oxide (IO), formaldehyde (HCHO), glyoxal (CHOCHO), nitrogen dioxide (NO2) and the oxygen dimer O4 in the coastal atmosphere of the Gulf of Mexico. The detection sensitivity of DOAS measurements is directly proportional to the root mean square (RMS) of the residual spectrum that remains after all absorbers have been subtracted. Here we describe the CU GMAX-DOAS instrument and demonstrate that the hardware is capable of attaining RMS values of ~6 × 10-6 without apparent limitations other than photon shot noise. Laboratory tests revealed two factors that, in practice, limit the RMS: (1) detector non-linearity noise, RMSNLin, and (2) temperature fluctuations that cause variations in optical resolution (full width at half the maximum, FWHM, of atomic emission lines) and give rise to optical resolution noise, RMSFWHM. The non-linearity of our detector is low (~10-3) yet - unless actively controlled - is sufficiently large to create a RMSNLin limit of up to 1.4 × 10-4. The optical resolution is sensitive to temperature changes (0.03 detector pixels/°C at 334 nm), and temperature variations of 0.1 °C can cause residual RMSFWHM of ~1 × 10-4. Both factors were actively addressed in the design of the CU GMAX-DOAS instrument. The CU GMAX-DOAS was set up at a coastal site near Pensacola, FL, where we detected BrO, IO and CHOCHO in the marine boundary layer (MBL), with daytime average tropospheric vertical column densities, VCDs, of ~2 × 1013 molec cm-2, 8 × 1012 molec cm-2 and 4 × 1014 molec cm-2, respectively. HCHO and NO2 were also detected with typical MBL VCDs of 1 × 1016 and 3 × 1015. These are the first measurements of BrO, IO and CHOCHO over the Gulf of Mexico. The atmospheric implications of these observations for elevated mercury wet deposition rates in this area are briefly

  5. Reliability assessment of a peer evaluation instrument in a team-based learning course

    Directory of Open Access Journals (Sweden)

    Wahawisan J

    2016-03-01

    Full Text Available Objective: To evaluate the reliability of a peer evaluation instrument in a longitudinal team-based learning setting. Methods: Student pharmacists were instructed to evaluate the contributions of their peers. Evaluations were analyzed for the variance of the scores by identifying low, medium, and high scores. Agreement between performance ratings within each group of students was assessed via intra-class correlation coefficient (ICC. Results: We found little variation in the standard deviation (SD based on the score means among the high, medium, and low scores within each group. The lack of variation in SD of results between groups suggests that the peer evaluation instrument produces precise results. The ICC showed strong concordance among raters. Conclusions: Findings suggest that our student peer evaluation instrument provides a reliable method for peer assessment in team-based learning settings.

  6. Ground-based hyperspectral analysis of the urban nightscape

    Science.gov (United States)

    Alamús, Ramon; Bará, Salvador; Corbera, Jordi; Escofet, Jaume; Palà, Vicenç; Pipia, Luca; Tardà, Anna

    2017-02-01

    Airborne hyperspectral cameras provide the basic information to estimate the energy wasted skywards by outdoor lighting systems, as well as to locate and identify their sources. However, a complete characterization of the urban light pollution levels also requires evaluating these effects from the city dwellers standpoint, e.g. the energy waste associated to the excessive illuminance on walls and pavements, light trespass, or the luminance distributions causing potential glare, to mention but a few. On the other hand, the spectral irradiance at the entrance of the human eye is the primary input to evaluate the possible health effects associated with the exposure to artificial light at night, according to the more recent models available in the literature. In this work we demonstrate the possibility of using a hyperspectral imager (routinely used in airborne campaigns) to measure the ground-level spectral radiance of the urban nightscape and to retrieve several magnitudes of interest for light pollution studies. We also present the preliminary results from a field campaign carried out in the downtown of Barcelona.

  7. Figure-ground organization based on three-dimensional symmetry

    Science.gov (United States)

    Michaux, Aaron; Jayadevan, Vijai; Delp, Edward; Pizlo, Zygmunt

    2016-11-01

    We present an approach to figure/ground organization using mirror symmetry as a general purpose and biologically motivated prior. Psychophysical evidence suggests that the human visual system makes use of symmetry in producing three-dimensional (3-D) percepts of objects. 3-D symmetry aids in scene organization because (i) almost all objects exhibit symmetry, and (ii) configurations of objects are not likely to be symmetric unless they share some additional relationship. No general purpose approach is known for solving 3-D symmetry correspondence in two-dimensional (2-D) camera images, because few invariants exist. Therefore, we present a general purpose method for finding 3-D symmetry correspondence by pairing the problem with the two-view geometry of the binocular correspondence problem. Mirror symmetry is a spatially global property that is not likely to be lost in the spatially local noise of binocular depth maps. We tested our approach on a corpus of 180 images collected indoors with a stereo camera system. K-means clustering was used as a baseline for comparison. The informative nature of the symmetry prior makes it possible to cluster data without a priori knowledge of which objects may appear in the scene, and without knowing how many objects there are in the scene.

  8. A compact ground-based laser heterodyne radiometer for global column measurements of CO2 and CH4

    Science.gov (United States)

    Steel, Emily; Clarke, Gregory; Ramanathan, Anand; Mao, Jianping; Ott, Lesley; Duncan, Bryan; Melroy, Hilary; McLinden, Matthew; Holben, Brent; Houston Miller, J.

    2015-04-01

    Implementing effective global strategies to understand climate change is hindered by a lack of understanding of both anthropogenic emissions and land and ocean carbon reservoirs. Though in situ surface measurements and satellites provide valuable information for estimating carbon fluxes, areas not well covered by current observing systems (e.g. high latitude regions, tropical forests and wetlands) remain poorly understood. Deficiencies in understanding the processes governing carbon flux introduce considerable uncertainty to predictions of climate change over the coming century. Our vision is to enhance worldwide carbon monitoring by developing a low-cost ground network of miniaturized laser heterodyne radiometer (Mini-LHR) instruments that measure CO2 and CH4 in the atmospheric column. Ground-based remote sensing has the potential to fill gaps in the satellite data record while providing a complementary long-term observational record. This uninterrupted data record, would both bridge gaps in data sets and offer validation for key flight missions such as OCO-2, OCO-3 and ASCENDS. Mini-LHR instruments will be deployed as an accompaniment to AERONET. In addition to the complementary aerosol optical depth measurement, tandem operation with AERONET provides a clear pathway for the Mini-LHR to be expanded into a global monitoring network. AERONET has more than 500 instruments worldwide offering coverage in key arctic regions (not covered by OCO-2) where accelerated warming due to the release of CO2 and CH4 from thawing tundra and permafrost is a concern. Mini-LHR instruments at AERONET locations could also greatly improve data coverage in regions with large flux uncertainties such as North America and Western Europe, and under-sampled areas such as South America and Asia. Currently, the only ground global network that routinely measures multiple greenhouse gases in the atmospheric column is TCCON with 18 operational sites worldwide and two in the US. Cost and size of

  9. Validation of NH3 satellite observations by ground-based FTIR measurements

    Science.gov (United States)

    Dammers, Enrico; Palm, Mathias; Van Damme, Martin; Shephard, Mark; Cady-Pereira, Karen; Capps, Shannon; Clarisse, Lieven; Coheur, Pierre; Erisman, Jan Willem

    2016-04-01

    Global emissions of reactive nitrogen have been increasing to an unprecedented level due to human activities and are estimated to be a factor four larger than pre-industrial levels. Concentration levels of NOx are declining, but ammonia (NH3) levels are increasing around the globe. While NH3 at its current concentrations poses significant threats to the environment and human health, relatively little is known about the total budget and global distribution. Surface observations are sparse and mainly available for north-western Europe, the United States and China and are limited by the high costs and poor temporal and spatial resolution. Since the lifetime of atmospheric NH3 is short, on the order of hours to a few days, due to efficient deposition and fast conversion to particulate matter, the existing surface measurements are not sufficient to estimate global concentrations. Advanced space-based IR-sounders such as the Tropospheric Emission Spectrometer (TES), the Infrared Atmospheric Sounding Interferometer (IASI), and the Cross-track Infrared Sounder (CrIS) enable global observations of atmospheric NH3 that help overcome some of the limitations of surface observations. However, the satellite NH3 retrievals are complex requiring extensive validation. Presently there have only been a few dedicated satellite NH3 validation campaigns performed with limited spatial, vertical or temporal coverage. Recently a retrieval methodology was developed for ground-based Fourier Transform Infrared Spectroscopy (FTIR) instruments to obtain vertical concentration profiles of NH3. Here we show the applicability of retrieved columns from nine globally distributed stations with a range of NH3 pollution levels to validate satellite NH3 products.

  10. Ground-based and airborne measurements of volcanic gas emissions at White Island in New Zealand

    Science.gov (United States)

    Tirpitz, Jan-Lukas; Poehler, Denis; Bobrowski, Nicole; Christenson, Bruce; Platt, Ulrich

    2017-04-01

    Quantitative understanding of volcanic gas emissions has twofold relevance for nature and society: 1) Variation in gas emission and/or in emitted gas ratios are tracers of the dynamic processes in the volcano interior indicating its activity. 2) Volcanic degassing plays an important role for the Earth's climate, for local sometimes even regional air quality and atmospheric chemistry. In autumn 2015, a campaign to White Island Volcano in New Zealand was organized to perform ground-based as well as airborne in-situ and remote sensing gas measurements of sulfur dioxide (SO2), carbon dioxide (CO2) and bromine monoxide (BrO). For all three gases the ratios and total emission rates were determined in different plume types and ages. An overview over the data will be presented with focus on the two most notable outcomes: 1) The first determination of the BrO/SO2 ratio in the White Island plume and a minimum estimate of the volcano's bromine emission rate; two of many parameters, which are important to assess the impact of volcanic degassing on the atmospheric halogen chemistry. 2) In-situ SO2 data was very successfully recorded with the PITSA, a prototype of a portable and cost-effective optical instrument. It is based on the principle of non-dispersive UV absorption spectroscopy and features different advantages over the customary electrochemical sensors, including a sub second response time, negligible cross sensitivities to other gases, and inherent calibration. The campaign data demonstrates the capabilities and limitations of the PITSA and shows, that it can be well applied as substitute for conventional electrochemical systems.

  11. Ground based interferometric radar initial look at Longview, Blue Springs, Tuttle Creek, and Milford Dams

    Science.gov (United States)

    Deng, Huazeng

    Measuring millimeter and smaller deformation has been demonstrated in the literature using RADAR. To address in part the limitations in current commercial satellite-based SAR datasets, a University of Missouri (MU) team worked with GAMMA Remote Sensing to develop a specialized (dual-frequency, polarimetric, and interferometric) ground-based real-aperture RADAR (GBIR) instrument. The GBIR device is portable with its tripod system and control electronics. It can be deployed to obtain data with high spatial resolution (i.e. on the order of 1 meter) and high temporal resolution (i.e. on the order 1 minute). The high temporal resolution is well suited for measurements of rapid deformation. From the same geodetic position, the GBIR may collect dual frequency data set using C-band and Ku-band. The overall goal of this project is to measure the deformation from various scenarios by applying the GBIR system. Initial efforts have been focusing on testing the system performance on different types of targets. This thesis details a number of my efforts on experimental and processing activities at the start of the MU GBIR imaging project. For improved close range capability, a wideband dual polarized antenna option was produced and tested. For GBIR calibration, several trihedral corner reflectors were designed and fabricated. In addition to experimental activities and site selection, I participated in advanced data processing activities. I processed GBIR data in several ways including single-look-complex (SLC) image generation, imagery registration, and interferometric processing. A number of initial-processed GBIR image products are presented from four dams: Longview, Blue Springs, Tuttle Creek, and Milford. Excellent imaging performance of the MU GBIR has been observed for various target types such as riprap, concrete, soil, rock, metal, and vegetation. Strong coherence of the test scene has been observed in the initial interferograms.

  12. Comparison of Ground- and Space-based Longitudinal Magnetograms

    CERN Document Server

    Pietarila, A; Harvey, J W; Pevtsov, A A

    2012-01-01

    We compare photospheric line-of-sight magnetograms from the Synoptic Long-term Investigations of the Sun (SOLIS) vector spectromagnetograph (VSM) instrument with observations from the 150-foot Solar Tower at Mt. Wilson (MWO), Helioseismic and Magnetic Imager (HMI) on Solar Dynamics Observatory (SDO), and Michelson Doppler Imager (MDI) on Solar and Heliospheric Observatory (SOHO). We find very good agreement between VSM and the other data sources for both disk-averaged flux densities and pixel-by-pixel measurements. We show that the VSM mean flux density time series is of consistently high signal-to-noise with no significant zero-offsets. We discuss in detail some of the factors -spatial resolution, flux dependence and position on the solar disk- affecting the determination of scaling between VSM and SOHO/MDI or SDO/HMI magnetograms. The VSM flux densities agree well with spatially smoothed data from MDI and HMI, although the scaling factors show clear dependence on flux density. The factor to convert VSM to H...

  13. Ground-based NIR emission spectroscopy of HD189733b

    CERN Document Server

    Waldmann, I P; Tinetti, G; Griffith, C A; Swain, M R; Deroo, P

    2011-01-01

    Spectroscopic observations of transiting exoplanets are providing an unprecedented view of the atmospheres of planets around nearby stars. As we learn more about the atmospheres of these remote bodies, we begin to build up a clearer picture of their composition and thermal structure. Here we investigate the case of K and L band emissions of the hot-Jupiter HD 189733b. Using the SpeX instrument on the NASA IRTF, we obtained three nights of secondary eclipse data using equivalent settings for all nights. Our sample includes one night previously presented by Swain et al. (2010) which allows for comparability of results. In this publication we present and discuss in detail a greatly improved data-reduction and analysis routine. This, in conjunction with more data, allows us to increase the spectral resolution of our planetary spectrum (R ~ 170-180), leading to a better identifiability of the features present. We confirm the existence of a strong emission at ~3.3 microns which is inconsistent with LTE simulations ...

  14. The CU ground MAX-DOAS instrument: characterization of RMS noise limitations and first measurements near Pensacola, FL of BrO, IO, and CHOCHO

    Directory of Open Access Journals (Sweden)

    S. Coburn

    2011-11-01

    Full Text Available We designed and assembled the University of Colorado Ground Multi AXis Differential Optical Absorption Spectroscopy (CU GMAX-DOAS instrument to retrieve bromine oxide (BrO, iodine oxide (IO, formaldehyde (HCHO, glyoxal (CHOCHO, nitrogen dioxide (NO2 and the oxygen dimer (O4 in the coastal atmosphere of the Gulf of Mexico. The detection sensitivity of DOAS measurements is proportional to the root mean square (RMS of the residual spectrum that remains after all absorbers have been subtracted. Here we describe the CU GMAX-DOAS instrument and demonstrate that the hardware is capable of attaining RMS of ∼6 × 10−6 from solar stray light noise tests using high photon count spectra (compatible within a factor of two with photon shot noise.

    Laboratory tests revealed two critical instrument properties that, in practice, can limit the RMS: (1 detector non-linearity noise, RMSNLin, and (2 temperature fluctuations that cause variations in optical resolution (full width at half the maximum, FWHM, of atomic emission lines and give rise to optical resolution noise, RMSFWHM. The non-linearity of our detector is low (∼10−2 yet – unless actively controlled – is sufficiently large to create RMSNLin of up to 2 × 10−4. The optical resolution is sensitive to temperature changes (0.03 detector pixels °C−1 at 334 nm, and temperature variations of 0.1°C can cause RMSFWHM of ~1 × 10−4. Both factors were actively addressed in the design of the CU GMAX-DOAS instrument. With an integration time of 60 s the instrument can reach RMS noise of 3 × 10−5, and typical RMS in field measurements ranged from 6 × 10−5 to 1.4 × 10−4.

    The CU GMAX-DOAS was set up at a coastal site near Pensacola, Florida, where we detected BrO, IO and CHOCHO in the marine boundary layer (MBL, with daytime

  15. The CU ground MAX-DOAS instrument: characterization of RMS noise limitations and first measurements near Pensacola, FL of BrO, IO, and CHOCHO

    Science.gov (United States)

    Coburn, S.; Dix, B.; Sinreich, R.; Volkamer, R.

    2011-11-01

    We designed and assembled the University of Colorado Ground Multi AXis Differential Optical Absorption Spectroscopy (CU GMAX-DOAS) instrument to retrieve bromine oxide (BrO), iodine oxide (IO), formaldehyde (HCHO), glyoxal (CHOCHO), nitrogen dioxide (NO2) and the oxygen dimer (O4) in the coastal atmosphere of the Gulf of Mexico. The detection sensitivity of DOAS measurements is proportional to the root mean square (RMS) of the residual spectrum that remains after all absorbers have been subtracted. Here we describe the CU GMAX-DOAS instrument and demonstrate that the hardware is capable of attaining RMS of ∼6 × 10-6 from solar stray light noise tests using high photon count spectra (compatible within a factor of two with photon shot noise). Laboratory tests revealed two critical instrument properties that, in practice, can limit the RMS: (1) detector non-linearity noise, RMSNLin, and (2) temperature fluctuations that cause variations in optical resolution (full width at half the maximum, FWHM, of atomic emission lines) and give rise to optical resolution noise, RMSFWHM. The non-linearity of our detector is low (∼10-2) yet - unless actively controlled - is sufficiently large to create RMSNLin of up to 2 × 10-4. The optical resolution is sensitive to temperature changes (0.03 detector pixels °C-1 at 334 nm), and temperature variations of 0.1°C can cause RMSFWHM of ~1 × 10-4. Both factors were actively addressed in the design of the CU GMAX-DOAS instrument. With an integration time of 60 s the instrument can reach RMS noise of 3 × 10-5, and typical RMS in field measurements ranged from 6 × 10-5 to 1.4 × 10-4. The CU GMAX-DOAS was set up at a coastal site near Pensacola, Florida, where we detected BrO, IO and CHOCHO in the marine boundary layer (MBL), with daytime average tropospheric vertical column densities (average of data above the detection limit), VCDs, of ∼2 × 1013 molec cm-2, 8 × 1012 molec cm-2 and 4 × 1014 molec cm-2, respectively. HCHO and

  16. DATA PROCESSING AND ANALYSIS TOOLS BASED ON GROUND-BASED SYNTHETIC APERTURE RADAR IMAGERY

    Directory of Open Access Journals (Sweden)

    M. Crosetto

    2017-09-01

    Full Text Available The Ground-Based SAR (GBSAR is a terrestrial remote sensing technique used to measure and monitor deformation. In this paper we describe two complementary approaches to derive deformation measurements using GBSAR data. The first approach is based on radar interferometry, while the second one exploits the GBSAR amplitude. In this paper we consider the so-called discontinuous GBSAR acquisition mode. The interferometric process is not always straightforward: it requires appropriate data processing and analysis tools. One of the main critical steps is phase unwrapping, which can critically affect the deformation measurements. In this paper we describe the procedure used at the CTTC to process and analyse discontinuous GBSAR data. In the second part of the paper we describe the approach based on GBSAR amplitude images and an image-matching method.

  17. Cloud Base Height and Effective Cloud Emissivity Retrieval with Ground-Based Infrared Interferometer

    Institute of Scientific and Technical Information of China (English)

    PAN Lin-Jun; LU Da-Ren

    2012-01-01

    Based on ground-based Atmospheric Emitted Radiance Interferometer (AERI) observations in Shouxian, Anhui province, China, the authors retrieve the cloud base height (CBH) and effective cloud emissivity by using the minimum root-mean-square difference method. This method was originally developed for satellite remote sensing. The high-temporal-resolution retrieval results can depict the trivial variations of the zenith clouds continu- ously. The retrieval results are evaluated by comparing them with observations by the cloud radar. The compari- son shows that the retrieval bias is smaller for the middle and low cloud, especially for the opaque cloud. When two layers of clouds exist, the retrieval results reflect the weighting radiative contribution of the multi-layer cloud. The retrieval accuracy is affected by uncertainties of the AERI radiances and sounding profiles, in which the role of uncertainty in the temperature profile is dominant.

  18. A Method for Modeling the Virtual Instrument Automatic Test System Based on the Petri Net

    Institute of Scientific and Technical Information of China (English)

    MA Min; CHEN Guang-ju

    2005-01-01

    Virtual instrument is playing the important role in automatic test system. This paper introduces a composition of a virtual instrument automatic test system and takes the VXIbus based a test software platform which is developed by CAT lab of the UESTC as an example. Then a method to model this system based on Petri net is proposed. Through this method, we can analyze the test task scheduling to prevent the deadlock or resources conflict. At last, this paper analyzes the feasibility of this method.

  19. The Pediatrics Milestones Assessment Pilot: Development of Workplace-Based Assessment Content, Instruments, and Processes.

    Science.gov (United States)

    Hicks, Patricia J; Margolis, Melissa; Poynter, Sue E; Chaffinch, Christa; Tenney-Soeiro, Rebecca; Turner, Teri L; Waggoner-Fountain, Linda; Lockridge, Robin; Clyman, Stephen G; Schwartz, Alan

    2016-05-01

    To report on the development of content and user feedback regarding the assessment process and utility of the workplace-based assessment instruments of the Pediatrics Milestones Assessment Pilot (PMAP). One multisource feedback instrument and two structured clinical observation instruments were developed and refined by experts in pediatrics and assessment to provide evidence for nine competencies based on the Pediatrics Milestones (PMs) and chosen to inform residency program faculty decisions about learners' readiness to serve as pediatric interns in the inpatient setting. During the 2012-2013 PMAP study, 18 U.S. pediatric residency programs enrolled interns and subinterns. Faculty, residents, nurses, and other observers used the instruments to assess learner performance through direct observation during a one-month rotation. At the end of the rotation, data were aggregated for each learner, milestone levels were assigned using a milestone classification form, and feedback was provided to learners. Learners and site leads were surveyed and/or interviewed about their experience as participants. Across the sites, 2,338 instruments assessing 239 learners were completed by 630 unique observers. Regarding end-of-rotation feedback, 93% of learners (128/137) agreed the assessments and feedback "helped me understand how those with whom I work perceive my performance," and 85% (117/137) agreed they were "useful for constructing future goals or identifying a developmental path." Site leads identified several benefits and challenges to the assessment process. PM-based instruments used in workplace-based assessment provide a meaningful and acceptable approach to collecting evidence of learner competency development. Learners valued feedback provided by PM-based assessment.

  20. GROUND FILTERING LiDAR DATA BASED ON MULTI-SCALE ANALYSIS OF HEIGHT DIFFERENCE THRESHOLD

    Directory of Open Access Journals (Sweden)

    P. Rashidi

    2017-09-01

    Full Text Available Separating point clouds into ground and non-ground points is a necessary step to generate digital terrain model (DTM from LiDAR dataset. In this research, a new method based on multi-scale analysis of height difference threshold is proposed for ground filtering of LiDAR data. The proposed method utilizes three windows with different sizes in small, average and large to cover the entire LiDAR point clouds, then with a height difference threshold, point clouds can be separated to ground and non-ground in each local window. Meanwhile, the best threshold values for size of windows are considered based on physical characteristics of the ground surface and size of objects. Also, the minimum of height of object in each window selected as height difference threshold. In order to evaluate the performance of the proposed algorithm, two datasets in rural and urban area were applied. The overall accuracy in rural and urban area was 96.06% and 94.88% respectively. These results of the filtering showed that the proposed method can successfully filters non-ground points from LiDAR point clouds despite of the data area.

  1. Low Power Ground-Based Laser Illumination for Electric Propulsion Applications

    Science.gov (United States)

    Lapointe, Michael R.; Oleson, Steven R.

    1994-01-01

    A preliminary evaluation of low power, ground-based laser powered electric propulsion systems is presented. A review of available and near-term laser, photovoltaic, and adaptive optic systems indicates that approximately 5-kW of ground-based laser power can be delivered at an equivalent one-sun intensity to an orbit of approximately 2000 km. Laser illumination at the proper wavelength can double photovoltaic array conversion efficiencies compared to efficiencies obtained with solar illumination at the same intensity, allowing a reduction in array mass. The reduced array mass allows extra propellant to be carried with no penalty in total spacecraft mass. The extra propellant mass can extend the satellite life in orbit, allowing additional revenue to be generated. A trade study using realistic cost estimates and conservative ground station viewing capability was performed to estimate the number of communication satellites which must be illuminated to make a proliferated system of laser ground stations economically attractive. The required number of satellites is typically below that of proposed communication satellite constellations, indicating that low power ground-based laser beaming may be commercially viable. However, near-term advances in low specific mass solar arrays and high energy density batteries for LEO applications would render the ground-based laser system impracticable.

  2. Designed microtremor array based actual measurement and analysis of strong ground motion at Palu city, Indonesia

    Science.gov (United States)

    Thein, Pyi Soe; Pramumijoyo, Subagyo; Brotopuspito, Kirbani Sri; Wilopo, Wahyu; Kiyono, Junji; Setianto, Agung; Putra, Rusnardi Rahmat

    2015-04-01

    In this study, we investigated the strong ground motion characteristics under Palu City, Indonesia. The shear wave velocity structures evaluated by eight microtremors measurement are the most applicable to determine the thickness of sediments and average shear wave velocity with Vs ≤ 300 m/s. Based on subsurface underground structure models identified, earthquake ground motion was estimated in the future Palu-Koro earthquake by using statistical green's function method. The seismic microzonation parameters were carried out by considering several significant controlling factors on ground response at January 23, 2005 earthquake.

  3. Designed microtremor array based actual measurement and analysis of strong ground motion at Palu city, Indonesia

    Energy Technology Data Exchange (ETDEWEB)

    Thein, Pyi Soe, E-mail: pyisoethein@yahoo.com [Geology Department, Yangon University (Myanmar); Pramumijoyo, Subagyo; Wilopo, Wahyu; Setianto, Agung [Geological Engineering Department, Gadjah Mada University (Indonesia); Brotopuspito, Kirbani Sri [Physics Department, Gadjah Mada University (Indonesia); Kiyono, Junji; Putra, Rusnardi Rahmat [Graduate School of Global Environmental Studies, Kyoto University (Japan)

    2015-04-24

    In this study, we investigated the strong ground motion characteristics under Palu City, Indonesia. The shear wave velocity structures evaluated by eight microtremors measurement are the most applicable to determine the thickness of sediments and average shear wave velocity with Vs ≤ 300 m/s. Based on subsurface underground structure models identified, earthquake ground motion was estimated in the future Palu-Koro earthquake by using statistical green’s function method. The seismic microzonation parameters were carried out by considering several significant controlling factors on ground response at January 23, 2005 earthquake.

  4. Investigating the long-term evolution of subtropical ozone profiles applying ground-based FTIR spectrometry

    Directory of Open Access Journals (Sweden)

    O. E. García

    2012-11-01

    Full Text Available This study investigates the long-term evolution of subtropical ozone profile time series (1999–2010 obtained from ground-based FTIR (Fourier Transform InfraRed spectrometry at the Izaña Observatory ozone super-site. Different ozone retrieval strategies are examined, analysing the influence of an additional temperature retrieval and different constraints. The theoretical assessment reveals that the FTIR system is able to resolve four independent ozone layers with a precision of better than 6% in the troposphere and of better than 3% in the lower, middle and upper stratosphere. This total error includes the smoothing error, which dominates the random error budget. Furthermore, we estimate that the measurement noise as well as uncertainties in the applied atmospheric temperature profiles and instrumental line shape are leading error sources. We show that a simultaneous temperature retrieval can significantly reduce the total random errors and that a regular determination of the instrumental line shape is important for producing a consistent long-term dataset. These theoretical precision estimates are empirically confirmed by daily intercomparisons with Electro Chemical Cell (ECC sonde profiles. In order to empirically document the long-term stability of the FTIR ozone profile data we compare the linear trends and seasonal cycles as obtained from the FTIR and ECC time series. Concerning seasonality, in winter both techniques observe stratospheric ozone profiles that are typical middle latitude profiles (low tropopause, low ozone maximum concentrations and in summer/autumn profiles that are typical tropical profiles (high tropopause, high maximum concentrations. The linear trends estimated from the FTIR and the ECC datasets agree within their error bars. For the FTIR time series, we observe a significant negative trend in the upper troposphere/lower stratosphere of about −0.2% yr−1 and a significant positive trend in the middle and

  5. Investigating the long-term evolution of subtropical ozone profiles applying ground-based FTIR spectrometry

    Science.gov (United States)

    García, O. E.; Schneider, M.; Redondas, A.; González, Y.; Hase, F.; Blumenstock, T.; Sepúlveda, E.

    2012-11-01

    This study investigates the long-term evolution of subtropical ozone profile time series (1999-2010) obtained from ground-based FTIR (Fourier Transform InfraRed) spectrometry at the Izaña Observatory ozone super-site. Different ozone retrieval strategies are examined, analysing the influence of an additional temperature retrieval and different constraints. The theoretical assessment reveals that the FTIR system is able to resolve four independent ozone layers with a precision of better than 6% in the troposphere and of better than 3% in the lower, middle and upper stratosphere. This total error includes the smoothing error, which dominates the random error budget. Furthermore, we estimate that the measurement noise as well as uncertainties in the applied atmospheric temperature profiles and instrumental line shape are leading error sources. We show that a simultaneous temperature retrieval can significantly reduce the total random errors and that a regular determination of the instrumental line shape is important for producing a consistent long-term dataset. These theoretical precision estimates are empirically confirmed by daily intercomparisons with Electro Chemical Cell (ECC) sonde profiles. In order to empirically document the long-term stability of the FTIR ozone profile data we compare the linear trends and seasonal cycles as obtained from the FTIR and ECC time series. Concerning seasonality, in winter both techniques observe stratospheric ozone profiles that are typical middle latitude profiles (low tropopause, low ozone maximum concentrations) and in summer/autumn profiles that are typical tropical profiles (high tropopause, high maximum concentrations). The linear trends estimated from the FTIR and the ECC datasets agree within their error bars. For the FTIR time series, we observe a significant negative trend in the upper troposphere/lower stratosphere of about -0.2% yr-1 and a significant positive trend in the middle and upper stratosphere of about +0

  6. New environmental policy instruments to realize forest expansion in Flanders (northern Belgium): A base for smart regulation?

    NARCIS (Netherlands)

    Gossum, Van P.; Ledene, L.; Arts, B.J.M.; Vreese, De R.; Langenhove, Van G.; Verheyen, K.

    2009-01-01

    This paper evaluates the current instrument mix, designs options for smart regulation and estimates the support base of new instruments for the forest expansion policy in Flanders (northern Belgium). The framework applied is a combination of theories on instrument choice (ICT), policy transfer and l

  7. A Psychometric Approach to the Development of a 5E Lesson Plan Scoring Instrument for Inquiry-Based Teaching

    Science.gov (United States)

    Goldston, M. Jenice; Dantzler, John; Day, Jeanelle; Webb, Brenda

    2013-01-01

    This research centers on the psychometric examination of the structure of an instrument, known as the 5E Lesson Plan (5E ILPv2) rubric for inquiry-based teaching. The instrument is intended to measure an individual's skill in developing written 5E lesson plans for inquiry teaching. In stage one of the instrument's development, an exploratory…

  8. Research on seamless development of surgical instruments based on biological mechanisms using CAD and 3D printer.

    Science.gov (United States)

    Yamamoto, Ikuo; Ota, Ren; Zhu, Rui; Lawn, Murray; Ishimatsu, Takakazu; Nagayasu, Takeshi; Yamasaki, Naoya; Takagi, Katsunori; Koji, Takehiko

    2015-01-01

    In the area of manufacturing surgical instruments, the ability to rapidly design, prototype and test surgical instruments is critical. This paper provides a simple case study of the rapid development of two bio-mechanism based surgical instruments which are ergonomic, aesthetic and were successfully designed, prototyped and conceptually tested in a very short period of time.

  9. Tropospheric BrO column densities in the Arctic derived from satellite: retrieval and comparison to ground-based measurements

    Directory of Open Access Journals (Sweden)

    H. Sihler

    2012-11-01

    Full Text Available During polar spring, halogen radicals like bromine monoxide (BrO play an important role in the chemistry of tropospheric ozone destruction. Satellite measurements of the BrO distribution have become a particularly useful tool to investigate this probably natural phenomenon, but the separation of stratospheric and tropospheric partial columns of BrO is challenging. In this study, an algorithm was developed to retrieve tropospheric vertical column densities of BrO from data of high-resolution spectroscopic satellite instruments such as the second Global Ozone Monitoring Experiment (GOME-2. Unlike recently published approaches, the presented algorithm is capable of separating the fraction of BrO in the activated troposphere from the total BrO column solely based on remotely measured properties. The presented algorithm furthermore allows to estimate a realistic measurement error of the tropospheric BrO column. The sensitivity of each satellite pixel to BrO in the boundary layer is quantified using the measured UV radiance and the column density of the oxygen collision complex O4. A comparison of the sensitivities with CALIPSO LIDAR observations demonstrates that clouds shielding near-surface trace-gas columns can be reliably detected even over ice and snow. Retrieved tropospheric BrO columns are then compared to ground-based BrO measurements from two Arctic field campaigns in the Amundsen Gulf and at Barrow in 2008 and 2009, respectively. Our algorithm was found to be capable of retrieving enhanced near-surface BrO during both campaigns in good agreement with ground-based data. Some differences between ground-based and satellite measurements observed at Barrow can be explained by both elevated and shallow surface layers of BrO. The observations strongly suggest that surface release processes are the dominating source of BrO and that boundary layer meteorology influences the vertical distribution.

  10. Tropospheric BrO column densities in the Arctic from satellite: retrieval and comparison to ground-based measurements

    Directory of Open Access Journals (Sweden)

    H. Sihler

    2012-05-01

    Full Text Available During polar spring, halogen radicals like bromine monoxide (BrO play an important role in the chemistry of tropospheric ozone destruction. Satellite measurements of the BrO-distribution have become a particularly useful tool to investigate this probably natural phenomenon, but the separation of stratospheric and tropospheric partial columns of BrO is challenging. In this study, an algorithm was developed to retrieve tropospheric vertical column densities of BrO from data of high-resolution spectroscopic satellite instruments such as the second Global Ozone Monitoring Experiment (GOME-2. Unlike recently published approaches, the presented algorithm is capable of separating the fraction of BrO in the activated troposphere from the total BrO column solely based on remotely measured properties. The sensitivity of each satellite pixel to BrO in the boundary-layer is quantified using the measured UV-radiance and the column density of the oxygen collision complex O4. A comparison of the sensitivities with CALIPSO LIDAR observations demonstrates that clouds shielding near-surface trace-gas columns can be reliably detected even over ice and snow. Retrieved tropospheric BrO columns are then compared to ground-based BrO measurements from two Arctic field campaigns in the Amundsen Gulf and at Barrow in 2008 and 2009, respectively. Our algorithm was found to be capable of retrieving enhanced near-surface BrO during both campaigns in good agreement to ground-based data. Some differences between ground-based and satellite measurements observed at Barrow can be explained by both, elevated and shallow surface layers of BrO. The observations strongly suggest that surface release processes are the dominating source of BrO and that boundary-layer meteorology influences the vertical distribution.

  11. A LAMP-based schematic prototype instrument for detection of microorganisms in human outer space activities

    Science.gov (United States)

    Hu, Yongfei; Liu, Zhiheng; Li, Junxiong; Zhu, Baoli

    One of the main tasks of human outer space exploration is to detect signs of life. Based on meteoritic evidence, common ancestry hypothesis has been posed. Therefore, searching for the fundamental molecules (DNA, RNA, and proteins) that constitute life as we know on Earth is feasible and now the typical approach. To achieve this goal, portable, robust, and highly sensitive instrument is also needed. In this study, based on Loop mediated isothermal amplification (LAMP) technique that targets life information storage molecular, DNA, we designed a schematic prototype instrument for microorganism detection. First, we designed LAMP primers used for amplification of DNA markers of Bacteria, Archaea, and Fungus; then, we optimized the LAMP reaction system for space using; and finally, we designed a prototype instrument and operating software system that are compatible with the LAMP reaction system. The results of simulation experiments showed that our instrument performed well for detecting representative microorganisms and the device can achieve semi-automatization. The detection process, from sample preparation to signal visualization, was completed in 1.5 hour. Our study provides a new method and corresponding device for detection of DNA molecular, which has great potential for applications in outer space exploration. Besides, the instrument we designed can also been used for monitoring changes of terrestrial microorganisms in outer space, for example in aircraft.

  12. DEVELOPMENT OF VIRTUAL INSTRUMENT IN CHARACTERISTIC ANALYSIS OF ROTATING MACHINERY BASED ON INSTANTANEOUS FREQUENCY ESTIMATION

    Institute of Scientific and Technical Information of China (English)

    Yang Jiongming; Qin Shuren; Ji Zhong; Guo Yu

    2004-01-01

    Based on the recently quick-developing time-frequency analysis (TFA) technique and virtual instrument (VI) technique, a virtual instrument in characteristic analysis of rotating machinery is researched and developed successfully. By utilizing instantaneous frequency estimation (IFE) theoretics of TFA technique, and based on IFE of peak searching on the time-frequency spectrum, order analysis (OA) functions is put forward and implemented, such as order spectrum, order spectrum matrix, order tracking, order tracking filtering, and order component extraction, etc. Unlike the home and abroad existing popular characteristic analyzers, which need key phasing devices such as shaft encoder, phase-locked loop (PLL), phase-locked multiple frequency, tachometer, etc, to implement constant angle sampling directly or indirectly, whereas this instrument only uses the vibration signal of rotating machinery to carry out OA. This instrument makes up the shortage of these traditional instruments in analyzing the non-stationary signal of run-up and run-down process of rotating machinery. Therefore, it is a great breakthrough for the existing order analyzers.

  13. Retrieval of sulphur dioxide from a ground-based thermal infrared imaging camera

    Directory of Open Access Journals (Sweden)

    A. J. Prata

    2014-02-01

    Full Text Available Recent advances in uncooled detector technology now offer the possibility of using relatively inexpensive thermal (7 to 14 μm imaging devices as tools for studying and quantifying the behaviour of hazardous gases and particulates in atmospheric plumes. An experimental fast-sampling (60 Hz ground-based uncooled thermal imager (Cyclops, operating with four spectral channels at central wavelengths of 8.6, 10, 11, and 12 μm and one broadband channel (7–14 μm, has been tested at several volcanoes and at two industrial sites, where SO2 was a major constituent of the plumes. This paper presents new algorithms, which include atmospheric corrections to the data and better calibrations to show that SO2 slant column density can be reliably detected and quantified. Our results indicate that it is relatively easy to identify and discriminate SO2 in plumes, but more challenging to quantify the column densities. A full description of the retrieval algorithms, illustrative results and a detailed error analysis are provided. The Noise-Equivalent Temperature Difference (NEΔT of the spectral channels, a fundamental measure of the quality of the measurements, lies between 0.4–0.8 K, resulting in slant column density errors of 20%. Frame averaging and improved NEΔT's can reduce this error to less than 10%, making a stand-off, day or night operation of an instrument of this type very practical for both monitoring industrial SO2 emissions and for SO2 column densities and emission measurements at active volcanoes. The imaging camera system may also be used to study thermal radiation from meteorological clouds and from the atmosphere.

  14. Eight-component retrievals from ground-based MAX-DOAS observations

    Directory of Open Access Journals (Sweden)

    H. Irie

    2011-06-01

    Full Text Available We attempt for the first time to retrieve lower-tropospheric vertical profile information for 8 quantities from ground-based Multi-Axis Differential Optical Absorption Spectroscopy (MAX-DOAS observations. The components retrieved are the aerosol extinction coefficients at two wavelengths, 357 and 476 nm, and NO2, HCHO, CHOCHO, H2O, SO2, and O3 volume mixing ratios. A Japanese MAX-DOAS profile retrieval algorithm, version 1 (JM1, is applied to observations performed at Cabauw, the Netherlands (51.97° N, 4.93° E, in June–July 2009 during the Cabauw Intercomparison campaign of Nitrogen Dioxide measuring Instruments (CINDI. Of the retrieved profiles, we focus here on the lowest-layer data (mean values at altitudes 0–1 km, where the sensitivity is usually highest owing to the longest light path. In support of the capability of the multi-component retrievals, we find reasonable overall agreement with independent data sets, including a regional chemical transport model (CHIMERE and in situ observations performed near the surface (2–3 m and at the 200-m height level of the tall tower in Cabauw. Plumes of enhanced HCHO and SO2 were likely affected by biogenic and ship emissions, respectively, and an improvement in their emission strengths is suggested for better agreement between CHIMERE simulations and MAX-DOAS observations. Analysis of air mass factors indicates that the horizontal spatial representativeness of MAX-DOAS observations is about 3–15 km (depending mainly on aerosol extinction, comparable to or better than the spatial resolution of current UV-visible satellite observations and model calculations. These demonstrate that MAX-DOAS provides multi-component data useful for the evaluation of satellite observations and model calculations and can play an important role in bridging different data sets having different spatial resolutions.

  15. Identifying and removing micro-drift in ground-based electromagnetic induction data

    Science.gov (United States)

    De Smedt, Philippe; Delefortrie, Samuël; Wyffels, Francis

    2016-08-01

    As the application of ground-based frequency domain electromagnetic induction (FDEM) surveys is on the rise, so increases the need for processing strategies that allow exploiting the full potential of these often large survey datasets. While a common issue is the detection of baseline drift affecting FDEM measurements, the impact of residual corrugations present after initial drift removal is less documented. Comparable to the influence of baseline drift, this 'micro-drift' introduces aberrant data fluctuations through time, independent of the true subsurface variability. Here, we present a method to detect micro-drift in drift-corrected FDEM survey data, therefore allowing its removal. The core of the procedure lies in approaching survey datasets as a time series. Hereby, discrete multi-level wavelet decomposition is used to isolate micro-drift in FDEM data. Detected micro-drift is then excluded in subsequent signal reconstruction to produce a more accurate FDEM dataset. While independently executed from ancillary information, tie-line measurements are used to evaluate the reliability and pitfalls of the procedure. This demonstrates how data levelling without evaluation data can increase subjectivity of the procedure, and shows the flexibility and efficiency of the approach in detecting minute drift effects. We corroborated the method through its application on three experimental field datasets, consisting of both quadrature and in-phase measurements gathered with different FDEM instruments. Through a 1D assessment of micro-drift, we show how it impacts FDEM survey data, and how it can be identified and accounted for in straightforward processing steps.

  16. Validation of stratospheric temperature profiles from a ground-based microwave radiometer with other techniques

    Science.gov (United States)

    Navas, Francisco; Kämpfer, Niklaus; Haefele, Alexander; Keckhut, Philippe; Hauchecorne, Alain

    2016-04-01

    Vertical profiles of atmospheric temperature trends has become recognized as an important indicator of climate change, because different climate forcing mechanisms exhibit distinct vertical warming and cooling patterns. For example, the cooling of the stratosphere is an indicator for climate change as it provides evidence of natural and anthropogenic climate forcing just like surface warming. Despite its importance, our understanding of the observed stratospheric temperature trend and our ability to test simulations of the stratospheric response to emissions of greenhouse gases and ozone depleting substances remains limited. One of the main reason is because stratospheric long-term datasets are sparse and obtained trends differ from one another. Different techniques allow to measure stratospheric temperature profiles as radiosonde, lidar or satellite. The main advantage of microwave radiometers against these other instruments is a high temporal resolution with a reasonable good spatial resolution. Moreover, the measurement at a fixed location allows to observe local atmospheric dynamics over a long time period, which is crucial for climate research. This study presents an evaluation of the stratospheric temperature profiles from a newly ground-based microwave temperature radiometer (TEMPERA) which has been built and designed at the University of Bern. The measurements from TEMPERA are compared with the ones from other different techniques such as in-situ (radiosondes), active remote sensing (lidar) and passive remote sensing on board of Aura satellite (MLS) measurements. In addition a statistical analysis of the stratospheric temperature obtained from TEMPERA measurements during four years of data has been performed. This analysis evidenced the capability of TEMPERA radiometer to monitor the temperature in the stratosphere for a long-term. The detection of some singular sudden stratospheric warming (SSW) during the analyzed period shows the necessity of these

  17. Fine spectral structures in Jovian decametric radio emission observed by ground-based radio telescope.

    Science.gov (United States)

    Panchenko, M.; Brazhenko, A. I.; Shaposhnikov, V. E.; Konovalenko, A. A.; Rucker, H. O.

    2014-04-01

    Jupiter with the largest planetary magnetosphere in the solar system emits intense coherent non-thermal radio emission in a wide frequency range. This emission is a result of a complicated interaction between the dynamic Jovian magnetosphere and energetic particles supplying the free energy from planetary rotation and the interaction between Jupiter and the Galilean moons. Decametric radio emission (DAM) is the strongest component of Jovian radiation observed in a frequency range from few MHz up to 40 MHz. This emission is generated via cyclotron maser mechanism in sources located along Jovian magnetic field lines. Depending on the time scales the Jovian DAMexhibits different complex spectral structures. We present the observations of the Jovian decametric radio emission using the large ground-based radio telescope URAN- 2 (Poltava, Ukraine) operated in the decametric frequency range. This telescope is one of the largest low frequency telescopes in Europe equipped with high performance digital radio spectrometers. The antenna array of URAN-2 consists of 512 crossed dipoles with an effective area of 28 000m2 and beam pattern size of 3.5 x 7 deg. (at 25 MHz). The instrument enables continuous observations of the Jovian radio during long period of times. Jovian DAM was observed continuously since Sep. 2012 (depending on Jupiter visibility) with relatively high time-frequency resolution (4 kHz - 100ms) in the broad frequency range (8-32MHz). We have detected a big amount of the fine spectral structures in the dynamic spectra of DAM such as trains of S-bursts, quasi-continuous narrowband emission, narrow-band splitting events and zebra stripe-like patterns. We analyzed mainly the fine structures associated with non-Io controlled DAM. We discuss how the observed narrowband structures which most probably are related to the propagation of the decametric radiation in the Jupiter's ionosphere can be used to study the plasma parameters in the inner Jovian magnetosphere.

  18. Eight-component retrievals from ground-based MAX-DOAS observations

    Directory of Open Access Journals (Sweden)

    H. Irie

    2011-01-01

    Full Text Available We attempt for the first time to retrieve lower-tropospheric vertical profile information for 8 quantities from ground-based Multi-Axis Differential Optical Absorption Spectroscopy (MAX-DOAS observations. The components retrieved are the aerosol extinction coefficients at two wavelengths, 357 and 476 nm and NO2, HCHO, CHOCHO, H2O, SO2, and O3 volume mixing ratios. A Japanese MAX-DOAS profile retrieval algorithm, version 1 (JM1, is applied to observations performed at Cabauw, the Netherlands (51.97° N, 4.93° E, in June–July 2009 during the Cabauw Intercomparison campaign of Nitrogen Dioxide measuring Instruments (CINDI. Of the retrieved profiles, we focus here on the lowest-layer data (mean values at altitudes 0–1 km, where the sensitivity is usually highest owing to the longest light path. In support of the capability of the multi-component retrievals, we find reasonable overall agreement with independent data sets, including a regional chemical transport model (CHIMERE and in situ observations performed at the 3 and 200 m height levels of the tall tower in Cabauw. Plumes of enhanced HCHO and SO2 were likely affected by biogenic and ship emissions, respectively, and an improvement in their emission strengths is suggested for better agreement between CHIMERE simulations and MAX-DOAS observations. Analysis of air mass factors indicates that the horizontal spatial representativeness of MAX-DOAS observations is about 3–15 km (depending mainly on aerosol extinction, comparable to or better than the spatial resolution of current UV-visible satellite observations and model calculations. These demonstrate that MAX-DOAS provides multi-component data useful for the evaluation of satellite observations and model calculations and can play an important role in bridging different data sets having different spatial resolutions.

  19. The 8-component retrievals from ground-based MAX-DOAS observations

    Science.gov (United States)

    Irie, H.; Takashima, H.; Kanaya, Y.; Boersma, F.; Gast, L.; Wittrock, F.; van Roozendael, M.

    2010-12-01

    We first attempt to retrieve lower-tropospheric vertical profile information on 8 components from ground-based Multi-Axis Differential Optical Absorption Spectroscopy (MAX-DOAS) observations. Components retrieved are aerosol extinction coefficients (AEC) at two wavelengths 357 and 476 nm, NO2, HCHO, CHOCHO, H2O, SO2, and O3 volume mixing ratios (VMRs). A Japanese MAX-DOAS profile retrieval algorithm version 1 (JM1) is applied to observations performed at Cabauw, the Netherlands (51.97N, 4.93E) in June-July 2009 during the Cabauw Intercomparison campaign of Nitrogen Dioxide measuring Instruments (CINDI). Of retrieved profiles, we focus here on the lowest layer data (mean values at altitudes 0-1 km), where the sensitivity is usually highest owing to the longest light path. In support of the capability of the multi-component retrievals, overall we find reasonable agreement with independent data sets, including a regional chemical transport model (CHIMERE) and in situ observations performed at 3- and 200-m height levels of a tower placed in Cabauw. Enhanced HCHO and SO2 plumes were likely affected by biogenic and ship emissions, respectively, but an improvement in their emission strengths was suggested for better agreement. Analysis of air mass factors indicates that the horizontal representativeness of MAX-DOAS observation is about 3-15 km, comparable to or better than the spatial resolution of relevant UV-visible satellite observations and model calculations. These demonstrate that MAX-DOAS provides multi-component data useful for evaluation of satellite observations and model calculations and plays a role in bridging different data sets having different spatial resolutions.

  20. Eight-component retrievals from ground-based MAX-DOAS observations

    Science.gov (United States)

    Irie, H.; Takashima, H.; Kanaya, Y.; Boersma, K. F.; Gast, L.; Wittrock, F.; Brunner, D.; Zhou, Y.; van Roozendael, M.

    2011-06-01

    We attempt for the first time to retrieve lower-tropospheric vertical profile information for 8 quantities from ground-based Multi-Axis Differential Optical Absorption Spectroscopy (MAX-DOAS) observations. The components retrieved are the aerosol extinction coefficients at two wavelengths, 357 and 476 nm, and NO2, HCHO, CHOCHO, H2O, SO2, and O3 volume mixing ratios. A Japanese MAX-DOAS profile retrieval algorithm, version 1 (JM1), is applied to observations performed at Cabauw, the Netherlands (51.97° N, 4.93° E), in June-July 2009 during the Cabauw Intercomparison campaign of Nitrogen Dioxide measuring Instruments (CINDI). Of the retrieved profiles, we focus here on the lowest-layer data (mean values at altitudes 0-1 km), where the sensitivity is usually highest owing to the longest light path. In support of the capability of the multi-component retrievals, we find reasonable overall agreement with independent data sets, including a regional chemical transport model (CHIMERE) and in situ observations performed near the surface (2-3 m) and at the 200-m height level of the tall tower in Cabauw. Plumes of enhanced HCHO and SO2 were likely affected by biogenic and ship emissions, respectively, and an improvement in their emission strengths is suggested for better agreement between CHIMERE simulations and MAX-DOAS observations. Analysis of air mass factors indicates that the horizontal spatial representativeness of MAX-DOAS observations is about 3-15 km (depending mainly on aerosol extinction), comparable to or better than the spatial resolution of current UV-visible satellite observations and model calculations. These demonstrate that MAX-DOAS provides multi-component data useful for the evaluation of satellite observations and model calculations and can play an important role in bridging different data sets having different spatial resolutions.

  1. Establishing common ground in community-based arts in health.

    Science.gov (United States)

    White, Mike

    2006-05-01

    This article originates in current research into community-based arts in health. Arts in health is now a diverse field of practice, and community-based arts in health interventions have extended the work beyond healthcare settings into public health. Examples of this work can now be found internationally in different health systems and cultural contexts. The paper argues that researchers need to understand the processes through which community-based arts in health projects evolve, and how they work holistically in their attempt to produce therapeutic and social benefits for both individuals and communities, and to connect with a cultural base in healthcare services themselves. A development model that might be adapted to assist in analysing this is the World Health Organisation Quality of Life Index (WHOQOL). Issues raised in the paper around community engagement, healthy choice and self-esteem are then illustrated in case examples of community-based arts in health practice in South Africa and England; namely the DramAide and Siyazama projects in KwaZulu-Natal, and Looking Well Healthy Living Centre in North Yorkshire. In South Africa there are arts and media projects attempting to raise awareness about HIV/AIDS through mass messaging, but they also recognize that they lack models of longer-term community engagement. Looking Well by contrast addresses health issues identified by the community itself in ways that are personal, empathic and domesticated. But there are also similarities among these projects in their aims to generate a range of social, educational and economic benefits within a community-health framework, and they are successfully regenerating traditional cultural forms to create public participation in health promotion. Process evaluation may provide a framework in which community-based arts in health projects, especially if they are networked together to share practice and thinking, can assess their ability to address health inequalities and focus

  2. Analysis of meteorological variables in the Australasian region using ground- and space-based GPS techniques

    Science.gov (United States)

    Kuleshov, Yuriy; Choy, Suelynn; Fu, Erjiang Frank; Chane-Ming, Fabrice; Liou, Yuei-An; Pavelyev, Alexander G.

    2016-07-01

    Results of analysis of meteorological variables (temperature and moisture) in the Australasian region using the global positioning system (GPS) radio occultation (RO) and GPS ground-based observations verified with in situ radiosonde (RS) data are presented. The potential of using ground-based GPS observations for retrieving column integrated precipitable water vapour (PWV) over the Australian continent has been demonstrated using the Australian ground-based GPS reference stations network. Using data from the 15 ground-based GPS stations, the state of the atmosphere over Victoria during a significant weather event, the March 2010 Melbourne storm, has been investigated, and it has been shown that the GPS observations has potential for monitoring the movement of a weather front that has sharp moisture contrast. Temperature and moisture variability in the atmosphere over various climatic regions (the Indian and the Pacific Oceans, the Antarctic and Australia) has been examined using satellite-based GPS RO and in situ RS observations. Investigating recent atmospheric temperature trends over Antarctica, the time series of the collocated GPS RO and RS data were examined, and strong cooling in the lower stratosphere and warming through the troposphere over Antarctica has been identified, in agreement with outputs of climate models. With further expansion of the Global Navigation Satellite Systems (GNSS) system, it is expected that GNSS satellite- and ground-based measurements would be able to provide an order of magnitude larger amount of data which in turn could significantly advance weather forecasting services, climate monitoring and analysis in the Australasian region.

  3. Ground-Based Surveillance and Tracking System (GSTS)

    Science.gov (United States)

    1987-08-01

    reported availabilty of relatively high- paying jobs. The consequences of increased migration could be significant. No significant impacts at U.S. Army...Air Force Base are contributing to overdrawing the aquifers, and at current usage rates the aquifers could be depleted (44). The "Draft Environmental

  4. Understanding How a Case-Based Assessment Instrument Influences Student Teachers' Learning Approaches

    Science.gov (United States)

    Segers, Mien; Martens, Rob; Van den Bossche, Piet

    2008-01-01

    In order to stimulate student teachers to thoroughly comprehend the main variables influencing their work, teaching and assessment strategies in teacher education have changed significantly. One of the changes in the assessment of student teachers in teacher education programs is the use of case-based assessment instruments. Such instruments…

  5. Explaining perceived oral texture of starch-based custard desserts from standard and novel instrumental tests

    NARCIS (Netherlands)

    Wijk, de R.A.; Prinz, J.F.; Janssen, A.M.

    2006-01-01

    A number of in vitro and in vivo instrumental tests have been developed to reflect various aspects of the perceived oral texture of starch-based vanilla custard desserts. These tests include measurements of the food's infra-red reflectance (IRR), of the turbidity of spat-out rinse water, and of the

  6. Evaluation of tropospheric and stratospheric ozone trends over Western Europe from ground-based FTIR network observations

    Directory of Open Access Journals (Sweden)

    C. Vigouroux

    2008-03-01

    Full Text Available Within the European project UFTIR (Time series of Upper Free Troposphere observations from an European ground-based FTIR network, six ground-based stations in Western Europe, from 79° N to 28° N, all equipped with Fourier Transform infrared (FTIR instruments and part of the Network for the Detection of Atmospheric Composition Change (NDACC, have joined their efforts to evaluate the trend of several direct and indirect greenhouse gases over the period 1995–2004. The retrievals of CO, CH4, C2H6, N2O, CHClF2, and O3 have been optimized. Using the optimal estimation method, some vertical information can be obtained in addition to total column amounts. A bootstrap resampling method has been implemented to determine annual partial and total column trends for the target gases. The present work focuses on the ozone results. The retrieved time series of partial and total ozone columns are validated with ground-based correlative data (Brewer, Dobson, UV-Vis, ozonesondes, and Lidar. The observed total column ozone trends are in agreement with previous studies: 1 no total column ozone trend is seen at the lowest latitude station Izaña (28° N; 2 slightly positive total column trends are seen at the two mid-latitude stations Zugspitze and Jungfraujoch (47° N, only one of them being significant; 3 the highest latitude stations Harestua (60° N, Kiruna (68° N and Ny-Ålesund (79° N show significant positive total column trends. Following the vertical information contained in the ozone FTIR retrievals, we provide partial columns trends for the layers: ground-10 km, 10–18 km, 18–27 km, and 27–42 km, which helps to distinguish the contributions from dynamical and chemical changes on the total column ozone trends. We obtain no statistically significant trends in the ground–10 km layer for five out of the six ground-based stations. We find significant positive trends for the lowermost

  7. Validation of middle-atmospheric campaign-based water vapour measured by the ground-based microwave radiometer MIAWARA-C

    Directory of Open Access Journals (Sweden)

    B. Tschanz

    2013-07-01

    Full Text Available Middle atmospheric water vapour can be used as a tracer for dynamical processes. It is mainly measured by satellite instruments and ground-based microwave radiometers. Ground-based instruments capable of measuring middle-atmospheric water vapour are sparse but valuable as they complement satellite measurements, are relatively easy to maintain and have a long lifetime. MIAWARA-C is a ground-based microwave radiometer for middle-atmospheric water vapour designed for use on measurement campaigns for both atmospheric case studies and instrument intercomparisons. MIAWARA-C's retrieval version 1.1 (v1.1 is set up in a such way as to provide a consistent data set even if the instrument is operated from different locations on a campaign basis. The sensitive altitude range for v1.1 extends from 4 hPa (37 km to 0.017 hPa (75 km. For v1.1 the estimated systematic error is approximately 10% for all altitudes. At lower altitudes it is dominated by uncertainties in the calibration, with altitude the influence of spectroscopic and temperature uncertainties increases. The estimated random error increases with altitude from 5 to 25%. MIAWARA-C measures two polarisations of the incident radiation in separate receiver channels, and can therefore provide two measurements of the same air mass with independent instrumental noise. The standard deviation of the difference between the profiles obtained from the two polarisations is in excellent agreement with the estimated random measurement error of v1.1. In this paper, the quality of v1.1 data is assessed for measurements obtained at two different locations: (1 a total of 25 months of measurements in the Arctic (Sodankylä, 67.37° N, 26.63° E and (2 nine months of measurements at mid-latitudes (Zimmerwald, 46.88° N, 7.46° E. For both locations MIAWARA-C's profiles are compared to measurements from the satellite experiments Aura MLS and MIPAS. In addition, comparisons to ACE-FTS and SOFIE are presented for the

  8. Ground based measurements of the gas emission from the Holuhraun volcanic fissure eruption on Iceland 2014/2015

    Science.gov (United States)

    Galle, Bo; Arellano, Santiago; Conde, Vladimir; Pfeffer, Melissa; Barsotti, Sara; Stefansdottir, Gerður; Bergsson, Baldur; Bergsson, Bergur; Ingvarsson, Thorgils; Weber, Konradin

    2015-04-01

    The since 31 August 2014 ongoing volcanic eruption at Holuhraun on Iceland is by far the strongest source of sulfur dioxide in Europe over the last 230 years with sustained emission rates exceeding 100 000 ton/day. This gas emission severely affects local population and has become a concern also for air traffic. The eruption has in December continued at constant pace for 3.5 months. Three scenarios are envisaged for the future; (1) the eruption stops, (2) the fissure extends under the Vattnajökul glacier and (3) Bardarbunga volcano erupts. The two later scenarios will cause increased gas emission, severe ash emissions and extended flooding. Under the scope of the EU-project FUTUREVOLC, a project with 3.5 years duration, aiming at making Iceland a supersite for volcanological research as a European contribution to GEO, we are developing a version of the Scanning DOAS instrument that is adapted to high latitudes with low UV radiation and severe meteorological conditions. Since the first day of the eruption several of these novel instruments has been monitoring the SO2 emission from the eruption. Data from our instruments are still after 3.5 months the only sustained ground-based monitoring of this gas emission. A lot of work is however needed to sustain this operation at a very remote site and under severe field conditions. At the same time the very high concentrations in the gas plume, in combination with bad meteorological conditions require the development of novel methods to derive reliable flux estimates. In this presentation we will discuss the instrumental issues and present the latest version of the emission estimates made from our measurements.

  9. Retrieval and validation of O3 measurements from ground-based FTIR spectrometer at equatorial station: Addis Ababa, Ethiopia

    Science.gov (United States)

    Takele Kenea, S.; Mengistu Tsidu, G.; Blumenstock, T.; Hase, F.; von Clarmann, T.; Stiller, G. P.

    2012-09-01

    Since May 2009 high-resolution Fourier transform infrared (FTIR) solar absorption spectra are recorded at Addis Ababa (9.01° N latitude, 38.76° E longitude, 2443 m altitude a.s.l.), Ethiopia. The vertical profiles and total column amounts of ozone (O3) are deduced from the spectra by using the retrieval code PROFFIT (V9.5) and regularly determined instrumental line shape (ILS). A detailed error analysis of the O3 retrieval is performed. Averaging kernels analysis of the target gas shows that the major contribution to the retrieved information always comes from the measurement. We obtained 2.1 degrees of freedom on average for signals in the retrieval of O3 from the observed FTIR spectra. We have compared the FTIR retrieval of ozone Volume Mixing Ratio (VMR) profiles and column amounts with the coincident satellite observations of Microwave Limb Sounding (MLS), Michelson Interferometer for Passive Atmospheric Sounding (MIPAS) and Tropospheric Emission Spectrometer (TES), Ozone Monitoring Instrument (OMI), Atmospheric Infrared Sounding (AIRS) and Global Ozone Monitoring Experiment (GOME-2) instrument. The mean relative differences are generally found below +15% in the altitude range of 27 to 36 km for comparison of VMR profiles made between MLS and MIPAS, whereas comparison with TES has shown below 9.4% relative difference. Furthermore, the mean relative difference is positive above 31 km, suggesting positive bias in the FTIR measurement of O3 VMR with respect to MLS, MIPAS and TES. The overall comparisons of column amounts of satellite measurements with the ground-based FTIR instruments show better agreement exhibiting mean relative differences of ground-based FTIR with respect to MLS and GOME-2 within +0.4% to +4.0% and corresponding standard deviations of 2.2 to 4.3% whereas, in the case of OMI, TES, AIRS, the mean relative differences are from -0.38 to -6.8%. Thus, the retrieved O3 VMR and column amounts from a tropical site, Addis Ababa, is found to exhibit

  10. Studies on aerosol properties during ICARB–2006 campaign period at Hyderabad, India using ground-based measurements and satellite data

    Indian Academy of Sciences (India)

    K V S Badarinath; Shailesh Kumar Kharol

    2008-07-01

    Continuous and campaign-based aerosol field measurements are essential in understanding fundamental atmospheric aerosol processes and for evaluating their effect on global climate, environment and human life. Synchronous measurements of Aerosol Optical Depth (AOD), Black Carbon (BC) aerosol mass concentration and aerosol particle size distribution were carried out during the campaign period at tropical urban regions of Hyderabad, India. Daily satellite datasets of DMSP-OLS were processed for night-time forest fires over the Indian region in order to understand the additional sources (forest fires) of aerosol. The higher values in black carbon aerosol mass concentration and aerosol optical depth correlated well with forest fires occurring over the region. Ozone Monitoring Instrument (OMI) aerosol index (AI) variations showed absorbing aerosols over the region and correlated with ground measurements.

  11. Spatial scale of the substorm onset region determined from multi-point satellite and ground-based observations

    Science.gov (United States)

    Nakamura, Rumi; Baker, D. N.; Belian, Richard D.; Yamamoto, T.

    1992-01-01

    The temporal and spatial scale of the onset of two substorm events is investigated using high resolution energetic particle and magnetic field data at synchronous orbit plus auroral and magnetic field data simultaneously taken from the ground based instrumentation. During both intervals the major expansion onset had precursor localized expansions without significant negative bay enhancement ('pseudobreakups'). Typical magnetospheric onset signatures such as tail current diversion, dipolarization, and injection were observed associated with some of the pseudobreakups. The major expansion, on the other hand, consisted of a number of rather localized injections and expansions, each of which had times scales of 5 to approximately 10 minutes, a comparable time scale to that of pseudobreakups. The number of occurrences, as well as the scale size of the magnetospheric source region, would constitute the major difference between pseudobreakup and the global expansion onset.

  12. Tracking of urban aerosols using combined lidar-based remote sensing and ground-based measurements

    Directory of Open Access Journals (Sweden)

    T.-Y. He

    2011-10-01

    Full Text Available A measuring campaign was performed over the neighboring towns of Nova Gorica in Slovenia and Gorizia in Italy on 24 and 25 May 2010, to investigate the concentration and distribution of urban aerosols. Tracking of two-dimensional spatial and temporal aerosol distributions was performed using scanning elastic lidar operating at 1064 nm. In addition, PM10 concentrations of particles, NOx and meteorological data were continuously monitored within the lidar scanning region. Based on the collected data, we investigated the flow dynamics and the aerosol concentrations within the lower troposphere and an evidence for daily aerosol cycles. We observed a number of cases with spatially localized increased lidar returns, which were found to be due to the presence of point sources of particulate matter. Daily aerosol concentration cycles were also clearly visible with a peak in aerosol concentration during the morning rush hours and daily maximum at around 17:00 Central European Time. We also found that the averaged horizontal atmospheric extinction within the scanning region 200 m above the ground is correlated to the PM10 concentration at the ground level with a correlation coefficient of 0.64, which may be due to relatively quiet meteorological conditions and basin-like terrain configuration.

  13. [Historical archives of Italian nephrology: The history of instrumentation in nephrology. Part I: Theoretical bases].

    Science.gov (United States)

    Timio, M

    2002-01-01

    Microscopes and artificial kidneys have greatly influenced both diagnosis and therapy of renal diseases. Nonetheless, in tracing the influence of instrumentation on nephrology, as revealed by daily activity, we have to recognise the influence of science upon medical instruments. It is for this reason that, besides strictly clinical factors, the scientific factors that contributed to the development of modern nephrology have received considerable attention. Nobody can use an artificial kidney without bearing in mind the contribution of many segments of science. Each segment has a hypothesis in its historical growth, development and decline. The notion that the advancement of science was made possible by the increasing reliance measurements and other quantitative procedure is hardly a novel one. Moreover, it is rather obvious that the experimental process and the use of instrumentation played an important role in the history of nephrology. Measurements, experiments and the use of instruments were interrelated and represented many phases of the improvements made in diagnosis and therapeutics. Naturally, in the history and epistemology of nephrology instrumentation we find conceptual mistakes and erroneous approaches to the biological reality. However, according to Popper's teachings, mistakes are good for science as they give an extra kick to its growth and development. Medical instrumentation is an assembly of scientific theories; it also controls medical theories and promotes the development of new ones. In addition, it changed our approach to the patient. In the pre-physical era, medical practice was almost entirely an intellectual process based on medical theories that the patient was not expected to understand. In the period of physical examinations the physician included the sensual dimension (oral and visual process) and made direct contact with the patient. In the instrumentation period we experience the third type of examination, in which the physician went

  14. Ground Based GPS Phase Measurements for Atmospheric Sounding

    Science.gov (United States)

    2016-06-14

    based GPS observations for the correction of radar observations. 6 REFERENCES Alber, C., R. Ware, C. Rocken, and J. Braun, A new method for sensing ...rocken@ucar.edu Award #: N00014-97-1-0258 LONG-TERM GOAL The goal is to develop GPS remote sensing techniques to determine atmospheric signal delay and...agrees best with the observations in a least squares sense is selected. The corresponding refractivity profile is then selected. • We tested this

  15. Constraint-based Ground contact handling in Humanoid Robotics Simulation

    OpenAIRE

    Martin Moraud, Eduardo; Hale, Joshua G.; Cheng, Gordon

    2008-01-01

    International audience; This paper presents a method for resolving contact in dynamic simulations of articulated figures. It is intended for humanoids with polygonal feet and incorporates Coulomb friction exactly. The proposed technique is based on a constraint selection paradigm. Its implementation offers an exact mode which guarantees correct behavior, as well as an efficiency optimized mode which sacrifices accuracy for a tightly bounded computational burden, thus facilitating batch simula...

  16. Prototype of a Dsp-Based Instrument for In-Service Wireless Transmitter Power Measurement

    Directory of Open Access Journals (Sweden)

    Angrisani Leopoldo

    2014-12-01

    Full Text Available A prototype of a DSP-based instrument for in-service transmitter power measurements is presented. The instrument implements a signal-selective algorithm for power measurements that is suitable for use in wireless environments, where possible uncontrolled interfering sources are present in the radio channel and are overlapped to the signal emitted by the transmitter under test, possibly in both time and frequency domain. The measurement method exploits the principles of cyclic spectral analysis, which are briefly recalled in the paper. Potentialities, as well as limitations of the prototype use are discussed, and the results of experiments with both modulated and unmodulated interfering sources are presented.

  17. [The development and transplantation of LCD module-based interface for medical diagnosis instrument].

    Science.gov (United States)

    Zhang, Huisheng; Liu, Xinyu; Li, Qiaoliang; Rao, Jie; Zhang, Xiaofei; Wang, Xiaoxuan; Lin, Shumei; Yin, Li; Chen, Siping; Wang, Tianfu

    2012-11-01

    Based on LCD Module and Visual C++ development environment, this paper proposes a new method which can quickly develop the human-machine interface .We define a LCD module programming interface by designing Serial Communication Class(SCS). On this basis,we achieve the transplantation on an Embedded ARM Platform to fulfil the requirements of Medical Diagnostic Instruments (MDI). Experimental results show that this method has advantages of short development cycle and high level transplantation which has broad application prospects in the field of Medical Diagnosis Instrument.

  18. Diode laser-based cavity ring-down instrument for NO3, N2O5, NO, NO2 and O3 from aircraft

    Directory of Open Access Journals (Sweden)

    T. B. Ryerson

    2011-06-01

    Full Text Available This article presents a diode laser-based, cavity ring-down spectrometer for simultaneous in situ measurements of four nitrogen oxide species, NO3, N2O5, NO, NO2, as well as O3, designed for deployment on aircraft. The instrument measures NO3 and NO2 by optical extinction at 662 nm and 405 nm, respectively; N2O5 is measured by thermal conversion to NO3, while NO and O3 are measured by chemical conversion to NO2. The instrument has several advantages over previous instruments developed by our group for measurement of NO2, NO3 and N2O5 alone, based on a pulsed Nd:YAG and dye laser. First, the use of continuous wave diode lasers reduces the requirements for power and weight and eliminates hazardous materials. Second, detection of NO2 at 405 nm is more sensitive than our previously reported 532 nm instrument, and does not have a measurable interference from O3. Third, the instrument includes chemical conversion of NO and O3 to NO2 to provide measurements of total NOx (= NO + NO2 and Ox (= NO2 + O3 on two separate channels; mixing ratios of NO and O3 are determined by subtraction of NO2. Finally, all five species are calibrated against a single standard based on 254 nm O3 absorption to provide high accuracy. Disadvantages include an increased sensitivity to water vapor on the 662 nm NO3 and N2O5 channels and a modest reduction in sensitivity for these species compared to the pulsed laser instrument. The in-flight detection limit for both NO3 and N2O5 is 3 pptv (2 σ, 1 s and for NO, NO2 and O3 is 140, 90, and 120 pptv (2 σ, 1 s respectively. Demonstrated performance of the instrument in a laboratory/ground based environment is better by approximately a factor of 2–3. The NO and NO2 measurements are less precise than research-grade chemiluminescence instruments. However, the combination of these five species in a single instrument, calibrated to a single analytical standard, provides a complete and accurate picture of nighttime nitrogen oxide

  19. Ground-based follow-up in relation to Kepler Asteroseismic Investigation

    CERN Document Server

    Uytterhoeven, K; Bruntt, H; De Cat, P; Frandsen, S; Gutierrez-Soto, J; Kiss, L; Kurtz, D W; Marconi, M; Molenda-Zakowicz, J; Ostensen, R; Randall, S; Southworth, J; Szabo, R

    2010-01-01

    The Kepler space mission, successfully launched in March 2009, is providing continuous, high-precision photometry of thousands of stars simultaneously. The uninterrupted time-series of stars of all known pulsation types are a precious source for asteroseismic studies. The Kepler data do not provide information on the physical parameters, such as effective temperature, surface gravity, metallicity, and vsini, which are crucial for successful asteroseismic modelling. Additional ground-based time-series data are needed to characterize mode parameters in several types of pulsating stars. Therefore, ground-based multi-colour photometry and mid/high-resolution spectroscopy are needed to complement the space data. We present ground-based activities within KASC on selected asteroseismic Kepler targets of several pulsation types. (Based on observations made with the Isaac Newton Telescope, William Herschel Telescope, Nordic Optical Telescope, Telescopio Nazionale Galileo, Mercator Telescope (La Palma, Spain), and IAC-...

  20. Comparison of airborne radar altimeter and ground-based Ku-band radar measurements on the ice cap Austfonna, Svalbard

    Directory of Open Access Journals (Sweden)

    O. Brandt

    2008-11-01

    Full Text Available We compare coincident data from the European Space Agency's Airborne SAR/Interferometric Radar Altimeter System (ASIRAS with ground-based Very High Bandwidth (VHB stepped-frequency radar measurements in the Ku-band. The ASIRAS instrument obtained data from ~700 m above the surface, using a 13.5 GHz center frequency and a 1 GHz bandwidth. The ground-based VHB radar measurements were acquired using the same center frequency, but with a variable bandwidth of either 1 or 8 GHz. Four sites were visited with the VHB radar; two sites within the transition region from superimposed ice to firn, and two sites in the long-term firn area (wet-snow zone. The greater bandwidth VHB measurements show that the first peak in the airborne data is a composite of the return from the surface (i.e. air-snow interface and returns of similar or stronger amplitude from reflectors in the upper ~30 cm of the subsurface. The peak position in the airborne data is thus not necessarily a good proxy for the surface since the maximum and width of the first return depend on the degree of interference between surface and subsurface reflectors. The major response from the winter snowpack was found to be caused by units of thin crust/ice layers (0.5–2 mm surrounded by large crystals (>3 mm. In the airborne data, it is possible to track such layers for tens of kilometers. The winter snowpack lacked thicker ice layers. The last year's summer surface, characterized by a low density large crystal layer overlaying a harder denser layer, gives a strong radar response, frequently the strongest. The clear relationship observed between the VHB and ASIRAS waveforms, justifies the use of ground-based radar measurements in the validation of air- or spaceborne radars.

  1. GravityCam: ground-based wide-field high-resolution imaging and high-speed photometry

    Science.gov (United States)

    Dominik, Martin; Mackay, Craig; Steele, Iain; Snodgrass, Colin; Hirsch, Michael; Gråe Jørgensen, Uffe; Hundertmark, Markus; Rebolo, Rafael; Horne, Keith; Bridle, Sarah; Sicardy, Bruno; Bramich, Daniel; Alsubai, Khalid

    2015-12-01

    The image blurring by the Earth's atmosphere generally poses a substantial limitation to ground-based observations. While opportunities in space are scarce, lucky imaging can correct over a much larger patch of sky and with much fainter reference stars. We propose the first of a new kind of versatile instruments, "GravityCam", composed of ~100 EMCCDs, that will open up two entirely new windows to ground-based astronomy: (1) wide-field high-resolution imaging, and (2) wide-field high-speed photometry. Potential applications include (a) a gravitational microlensing survey going 4 magnitudes deeper than current efforts, and thereby gaining a factor 100 in mass at the same sensitivity, which means probing down to Lunar mass or even below, (b) extra-solar planet hunting via transits in galactic bulge fields, with high time resolution well-suited for transit timing variation studies, (c) variable stars in crowded fields, with sensitivity to very short periods, (d) asteroseismology with many bright stars in one pointing, (e) serendipitous occultations of stars by small solar system bodies, giving access to the small end of the Kuiper Belt size distribution and potentially leading to the first detection of true Oort cloud objects, while predicted occultations at high time resolution can reveal atmospheres, satellites, or rings, (f) general data mining of the high-speed variable sky (down to 40 ms cadence).

  2. Investigation the optical and radiative properties of aerosol vertical profile of boundary layer by lidar and ground based measurements

    Science.gov (United States)

    Chen, W.; Chou, C.; Lin, P.; Wang, S.

    2011-12-01

    The planetary boundary layer is the air layer near the ground directly affected by diurnal heat, moisture, aerosol, and cloud transfer to or from the surface. In the daytime solar radiation heats the surface, initiating thermal instability or convection. Whereas, the scattering and absorption of aerosols or clouds might decrease the surface radiation or heat atmosphere which induce feedbacks such as the enhanced stratification and change in relative humidity in the boundary layer. This study is aimed to understand the possible radiative effect of aerosols basing on ground based aerosol measurements and lidar installed in National Taiwan University in Taipei. The optical and radiative properties of aerosols are dominated by aerosol composition, particle size, hygroscopicity property, and shape. In this study, aerosol instruments including integrating nephelometer, open air nephelometer, aethalometer are applied to investigate the relationship between aerosol hygroscopicity properties and aerosol types. The aerosol hygroscopicity properties are further applied to investigate the effect of relative humidity on aerosol vertical profiles measured by a dual-wavelength and depolarization lidar. The possible radiative effect of aerosols are approached by vertical atmospheric extinction profiles measured by lidar. Calculated atmospheric and aerosol heating effects was compared with vertical meteorological parameters measured by radiosonde. The result shows light-absorbing aerosol has the potential to affect the stability of planetary boundary layer.

  3. Influence of Desert Dust Intrusions on Ground-based and Satellite Derived Ultraviolet Irradiance in Southeastern Spain

    Science.gov (United States)

    Krotkov, Nickolay A.; Anton, Manuel; Valenzuela, Antonio; Roman, Roberto; Lyamani, Hassan; Arola, Antti; Olmo, Francisco J.; Alados-Arboledas

    2012-01-01

    The desert dust aerosols strongly affect propagation of solar radiation through the atmosphere, reducing surface irradiance available for photochemistry and photosynthesis. This paper evaluates effects of desert dust on surface UV erythemal irradiance (UVER), as measured by a ground-based broadband UV radiometer and retrieved from the satellite Ozone Monitoring Instrument (OMI) at Granada (southern Spain) from January 2006 to December 2010. The dust effects are characterized by the transmittance ra tio of the measured UVER to the corresponding modeled clear sky value. The transmittance has an exponential dependency on aerosol optical depth (AOD), with minimum values of approximately 0.6 (attenuation of approximately 40%). The OMI UVER algorithm does not account for UV aerosol absorption, which results in overestimation of the ground-based UVER especially during dust episodes with a mean relative difference up to 40%. The application of aerosol absorption post-correction method reduces OMI bias up to approximately 13%. The results highlight great effect of desert dust on the surface UV irradiance in regions like southern Spain, where dust intrusions from Sahara region are very frequent.

  4. Portable generator-based XRF instrument for non-destructive analysis at crime scenes

    Science.gov (United States)

    Schweitzer, Jeffrey S.; Trombka, Jacob I.; Floyd, Samuel; Selavka, Carl; Zeosky, Gerald; Gahn, Norman; McClanahan, Timothy; Burbine, Thomas

    2005-12-01

    Unattended and remote detection systems find applications in space exploration, telemedicine, teleforensics, homeland security and nuclear non-proliferation programs. The National Institute of Justice (NIJ) and the National Aeronautics and Space Administration's (NASA) Goddard Space Flight Center (GSFC) have teamed up to explore the use of NASA developed technologies to help criminal justice agencies and professionals investigate crimes. The objective of the program is to produce instruments and communication networks that have application within both NASA's space program and NIJ, together with state and local forensic laboratories. A general-purpose X-ray fluorescence system has been built for non-destructive analyses of trace and invisible material at crime scenes. This portable instrument is based on a generator that can operate to 60 kV and a Schottky CdTe detector. The instrument has been shown to be successful for the analysis of gunshot residue and a number of bodily fluids at crime scenes.

  5. Target Diagnostic Instrument-Based Controls Framework for the National Ignition Facility (NIF)

    Energy Technology Data Exchange (ETDEWEB)

    Shelton, R T; O' Brien, D W; Kamperschroer, J H; Nelson, J R

    2007-10-03

    The extreme physics of targets shocked by NIF's 192-beam laser are observed by a diverse suite of diagnostics including optical backscatter, time-integrated and gated X-ray sensors, and laser velocity interferometry. Diagnostics to diagnose fusion ignition implosion and neutron emissions are being planned. Many diagnostics will be developed by collaborators at other sites, but ad hoc controls could lead to unreliable and costly operations. An instrument-based controls (I-BC) framework for both hardware and software facilitates development and eases integration. Each complex diagnostic typically uses an ensemble of electronic instruments attached to sensors, digitizers, cameras, and other devices. In the I-BC architecture each instrument is interfaced to a low-cost Windows XP processor and Java application. Each instrument is aggregated with others as needed in the supervisory system to form an integrated diagnostic. The Java framework provides data management, control services and operator GUI generation. I-BCs are reusable by replication and reconfiguration for specific diagnostics in XML. Advantages include minimal application code, easy testing, and better reliability. Collaborators save costs by assembling diagnostics with existing I-BCs. This paper discusses target diagnostic instrumentation used on NIF and presents the I-BC architecture and framework.

  6. A portable, low coherence interferometry based instrument for fine needle aspiration biopsy guidance

    Science.gov (United States)

    Iftimia, Nicusor V.; Bouma, Brett E.; Pitman, Martha B.; Goldberg, Brian; Bressner, Jason; Tearney, Guillermo J.

    2005-06-01

    A portable, low coherence interferometry (LCI) based instrument for fine-needle aspiration biopsy guidance is presented. The instrument consists of a fiber-based low coherence interferometer, a data acquisition, processing and display unit, and a probe. The probe, consisting of a 250μm diameter single-mode optical fiber inserted within the bore of a fine needle, is used to illuminate tissue and collect light from tissue at the tip of the needle. Light returning out of the probe is detected by the LCI system, which is capable of measuring depth-resolved information (reflectivity, spectra, birefringence) with a spatial resolution of 10μm over a depth range of approximately 1.4mm. The LCI based instrument can be used to guide the fine needle during biopsy procedures to potentially diagnose neoplasms, infections, inflammations, or infiltrations. The design and performance of the instrument, as well as preliminary measurements on excised breast tissue specimens, are presented in detail.

  7. Analysis of English Complex Sentences based on Figure-Ground Theory

    Institute of Scientific and Technical Information of China (English)

    侯皓

    2015-01-01

    English is a language featuring its complex sentences composed of main and sub-ordinate clauses. The subordinate clause conveys the unifnished messages in main clause and it becomes quite complicated. English complex sentence is a fair impor-tant sentence type and also of importance in English teaching. Analyzing complex sentence based on Figure-Ground Theory, especially the Adverbial Clause, is help-ful to learn English and translate it. The Figure-Ground Theory originated in psychol-ogy studies and it was introduced in cognitive linguistics to explain some language phenomena. From Figure-Ground perspective, the essay studies attributive clause, adverbial clause and nominal clause and some critical sentence types have been analyzed carefully and the major ifnding is Figure-Ground Theory is dynamic not static.

  8. Novel identification strategy for ground coffee adulteration based on UPLC-HRMS oligosaccharide profiling.

    Science.gov (United States)

    Cai, Tie; Ting, Hu; Jin-Lan, Zhang

    2016-01-01

    Coffee is one of the most common and most valuable beverages. According to International Coffee Organization (ICO) reports, the adulteration of coffee for financial reasons is regarded as the most serious threat to the sustainable development of the coffee market. In this work, a novel strategy for adulteration identification in ground coffee was developed based on UPLC-HRMS oligosaccharide profiling. Along with integrated statistical analysis, 17 oligosaccharide composition were identified as markers for the identification of soybeans and rice in ground coffee. This strategy, validated by manual mixtures, optimized both the reliability and authority of adulteration identification. Rice and soybean adulterants present in ground coffee in amounts as low as 5% were identified and evaluated. Some commercial ground coffees were also successfully tested using this strategy.

  9. Coastal wind study based on Sentinel-1 and ground-based scanning lidar

    DEFF Research Database (Denmark)

    Ahsbahs, Tobias Torben; Badger, Merete; Pena Diaz, Alfredo

    , the project "Reducing the Uncertainty of Near-shore Energy estimates from meso- and micro-scale wind models" (RUNE) was established. The lidar measurement campaign started November 2015 and ended in February 2016 at the Danish North Sea coast at around 56.5 ◦N, 8.2 ◦E. 107 satellite SAR scenes were collected...... fields from the Sentinel-1A satellite using APL/NOAA’s SAROPS system with GFS model wind directions as input. For the presented cases CMOD5.n is used. Ground-based scanning lidar located on land can also cover near shore areas. In order to improve wind farm planning for near-shore coastal areas...

  10. Instruments and Experiments Control Methodology Based on IVI and LXI Technologies

    OpenAIRE

    Unai Hernandez

    2011-01-01

    In this paper we present a new model to control the instruments and experiments in a remote laboratory. This model is based on LAN networks and a control methodology through reusable drivers. The objective is to obtain a software control architecture independent of the hardware of the laboratory, so each institution can use its own equipments and experiments based on its needs and with minimal restrictions regarding to the hardware of the lab.

  11. Dust optical properties retrieved from ground-based polarimetric measurements.

    Science.gov (United States)

    Li, Zhengqiang; Goloub, Philippe; Blarel, Luc; Damiri, Bahaiddin; Podvin, Thierry; Jankowiak, Isabelle

    2007-03-20

    We have systematically processed one year of sunphotometer measurements (recorded at five AERONET/PHOTONS sites in Africa) in order to assess mineral dust optical properties with the use of a new polarimetry-based algorithm. We consider the Cimel CE318 polarized sunphotometer version to obtain single-scattering albedo, scattering phase matrix elements F(11) and F(12) for dust aerosols selected with Angström exponents ranging from -0.05 to 0.25. Retrieved F(11) and F(12) differ significantly from those of spherical particles. The degree of linear polarization -F(12)/F(11) for single scattering of atmospheric total column dust aerosols in the case of unpolarized incident light is systematically retrieved for the first time to our knowledge from sunphotometer measurements and shows consistency with previous laboratory characterizations of nonspherical particles.

  12. Top-down estimation of carbon monoxide emissions from the Mexico Megacity based on FTIR measurements from ground and space

    Directory of Open Access Journals (Sweden)

    W. Stremme

    2012-11-01

    Full Text Available Continuous carbon monoxide (CO total column densities above the UNAM campus in Mexico City have been derived from solar absorption infrared spectroscopic measurements since October 2007. Its diurnal evolution is used in the present study in conjunction with other ground-based and satellite data to develop a top-down emission estimate of the annual CO emission of the Mexico City Metropolitan Area (MCMA. The growth-rate of the total column around noon under low ventilation conditions is calculated and allows us to derive the average surface emission-flux at UNAM, while similar measurements taken at the edge of the MCMA in Tecámac provides information on background CO levels in the Mexico basin. Based on 3 yr of measurements, CO column measurements from the IASI satellite instrument are used to reconstruct the spatial distribution of this anthropogenic pollutant over the MCMA. The agreement between the measured columns of the satellite and ground-based measurements is excellent, particularly when a comparison strategy based on time-displaced air masses is used. The annual emission of the Mexico Megacity is estimated to be (2.15 ± 0.5 Tg yr−1 for the year 2008, while the official inventory for that year reported 1.6 Tg yr−1. The difference is slightly higher than the conservative uncertainty estimated in this work suggesting that the emission might be underestimated by the conventional bottom-up method. A larger discrepancy is found in the spatial distribution of the emissions, when comparing the emission flux over UNAM (derived from the ground-based measurement with that of the inventory integrated over a representative area. The methodology presented here represents a new and useful strategy to evaluate the contribution of megacities to the global anthropogenic gas emissions. Additionally, three different strategies to compare ground and space-based measurements above an inhomogeneous and strongly contaminated area like

  13. On a preference-based instrumental variable approach in reducing unmeasured confounding-by-indication.

    Science.gov (United States)

    Li, Yun; Lee, Yoonseok; Wolfe, Robert A; Morgenstern, Hal; Zhang, Jinyao; Port, Friedrich K; Robinson, Bruce M

    2015-03-30

    Treatment preferences of groups (e.g., clinical centers) have often been proposed as instruments to control for unmeasured confounding-by-indication in instrumental variable (IV) analyses. However, formal evaluations of these group-preference-based instruments are lacking. Unique challenges include the following: (i) correlations between outcomes within groups; (ii) the multi-value nature of the instruments; (iii) unmeasured confounding occurring between and within groups. We introduce the framework of between-group and within-group confounding to assess assumptions required for the group-preference-based IV analyses. Our work illustrates that, when unmeasured confounding effects exist only within groups but not between groups, preference-based IVs can satisfy assumptions required for valid instruments. We then derive a closed-form expression of asymptotic bias of the two-stage generalized ordinary least squares estimator when the IVs are valid. Simulations demonstrate that the asymptotic bias formula approximates bias in finite samples quite well, particularly when the number of groups is moderate to large. The bias formula shows that when the cluster size is finite, the IV estimator is asymptotically biased; only when both the number of groups and cluster size go to infinity, the bias disappears. However, the IV estimator remains advantageous in reducing bias from confounding-by-indication. The bias assessment provides practical guidance for preference-based IV analyses. To increase their performance, one should adjust for as many measured confounders as possible, consider groups that have the most random variation in treatment assignment and increase cluster size. To minimize the likelihood for these IVs to be invalid, one should minimize unmeasured between-group confounding.

  14. Development and characterization of the CU ground MAX-DOAS instrument: lowering RMS noise and first measurements of BrO, IO, and CHOCHO near Pensacola, FL

    Directory of Open Access Journals (Sweden)

    S. Coburn

    2011-01-01

    Full Text Available We designed and assembled the University of Colorado Ground Multi AXis Differential Optical Absorption Spectroscopy (CU GMAX-DOAS instrument to retrieve bromine oxide (BrO, iodine oxide (IO, formaldehyde (HCHO, glyoxal (CHOCHO, nitrogen dioxide (NO2 and the oxygen dimer O4 in the coastal atmosphere of the Gulf of Mexico. The detection sensitivity of DOAS measurements is directly proportional to the root mean square (RMS of the residual spectrum that remains after all absorbers have been subtracted. Here we describe the CU GMAX-DOAS instrument and demonstrate that the hardware is capable of attaining RMS values of ~6 × 10-6 without apparent limitations other than photon shot noise.

    Laboratory tests revealed two factors that, in practice, limit the RMS: (1 detector non-linearity noise, RMSNLin, and (2 temperature fluctuations that cause variations in optical resolution (full width at half the maximum, FWHM, of atomic emission lines and give rise to optical resolution noise, RMSFWHM. The non-linearity of our detector is low (~10−3 yet – unless actively controlled – is sufficiently large to create a RMSNLin limit of up to 1.4 × 10-4. The optical resolution is sensitive to temperature changes (0.03 detector pixels/°C at 334 nm, and temperature variations of 0.1 °C can cause residual RMSFWHM of ~1 × 10-4. Both factors were actively addressed in the design of the CU GMAX-DOAS instrument.

    The CU GMAX-DOAS was set up at a coastal site near Pensacola, FL, where we detected BrO, IO and CHOCHO in the marine boundary layer (MBL, with daytime average tropospheric vertical column densities, VCDs, of ~2 × 1013 molec cm−2, 8 × 1012 molec cm−2 and 4 × 1014 molec cm−2, respectively. HCHO and NO2 were also detected with typical MBL VCDs of 1

  15. Design and validation of a standards-based science teacher efficacy instrument

    Science.gov (United States)

    Kerr, Patricia Reda

    National standards for K--12 science education address all aspects of science education, with their main emphasis on curriculum---both science subject matter and the process involved in doing science. Standards for science teacher education programs have been developing along a parallel plane, as is self-efficacy research involving classroom teachers. Generally, studies about efficacy have been dichotomous---basing the theoretical underpinnings on the work of either Rotter's Locus of Control theory or on Bandura's explanations of efficacy beliefs and outcome expectancy. This study brings all three threads together---K--12 science standards, teacher education standards, and efficacy beliefs---in an instrument designed to measure science teacher efficacy with items based on identified critical attributes of standards-based science teaching and learning. Based on Bandura's explanation of efficacy being task-specific and having outcome expectancy, a developmental, systematic progression from standards-based strategies and activities to tasks to critical attributes was used to craft items for a standards-based science teacher efficacy instrument. Demographic questions related to school characteristics, teacher characteristics, preservice background, science teaching experience, and post-certification professional development were included in the instrument. The instrument was completed by 102 middle level science teachers, with complete data for 87 teachers. A principal components analysis of the science teachers' responses to the instrument resulted in two components: Standards-Based Science Teacher Efficacy: Beliefs About Teaching (BAT, reliability = .92) and Standards-Based Science Teacher Efficacy: Beliefs About Student Achievement (BASA, reliability = .82). Variables that were characteristic of professional development activities, science content preparation, and school environment were identified as members of the sets of variables predicting the BAT and BASA

  16. Tracing ground water input to base flow using sulfate (S, O) isotopes.

    Science.gov (United States)

    Gu, Ailiang; Gray, Floyd; Eastoe, Christopher J; Norman, Laura M; Duarte, Oscar; Long, Austin

    2008-01-01

    Sulfate (S and O) isotopes used in conjunction with sulfate concentration provide a tracer for ground water contributions to base flow. They are particularly useful in areas where rock sources of contrasting S isotope character are juxtaposed, where water chemistry or H and O isotopes fail to distinguish water sources, and in arid areas where rain water contributions to base flow are minimal. Sonoita Creek basin in southern Arizona, where evaporite and igneous sources of sulfur are commonly juxtaposed, serves as an example. Base flow in Sonoita Creek is a mixture of three ground water sources: A, basin ground water with sulfate resembling that from Permian evaporite; B, ground water from the Patagonia Mountains; and C, ground water associated with Temporal Gulch. B and C contain sulfate like that of acid rock drainage in the region but differ in sulfate content. Source A contributes 50% to 70%, with the remainder equally divided between B and C during the base flow seasons. The proportion of B generally increases downstream. The proportion of A is greatest under drought conditions.

  17. Tracing ground water input to base flow using sulfate (S, O) isotopes

    Science.gov (United States)

    Gu, A.; Gray, F.; Eastoe, C.J.; Norman, L.M.; Duarte, O.; Long, A.

    2008-01-01

    Sulfate (S and O) isotopes used in conjunction with sulfate concentration provide a tracer for ground water contributions to base flow. They are particularly useful in areas where rock sources of contrasting S isotope character are juxtaposed, where water chemistry or H and O isotopes fail to distinguish water sources, and in arid areas where rain water contributions to base flow are minimal. Sonoita Creek basin in southern Arizona, where evaporite and igneous sources of sulfur are commonly juxtaposed, serves as an example. Base flow in Sonoita Creek is a mixture of three ground water sources: A, basin ground water with sulfate resembling that from Permian evaporite; B, ground water from the Patagonia Mountains; and C, ground water associated with Temporal Gulch. B and C contain sulfate like that of acid rock drainage in the region but differ in sulfate content. Source A contributes 50% to 70%, with the remainder equally divided between B and C during the base flow seasons. The proportion of B generally increases downstream. The proportion of A is greatest under drought conditions.

  18. A framework for recovery-oriented, COTS-based ground station networks

    Science.gov (United States)

    Cutler, James William

    The complexity of space communication has limited our access to space systems and kept mission operations costs high. Ultimately, this results in reduced mission capabilities and yields. In particular, ground stations, the access point between space and terrestrial networks, suffer from monolithic designs, narrow interfaces, and unreliability that raise significant financial barriers for low-cost, experimental satellite missions. This research reduces these barriers by developing technology for recovery-oriented, flexible access networks built from commercial-off-the-shelf (COTS) components. Based on our extensive small satellite experiences, we decomposed ground station services and captured them in an extensible framework that simplified reuse of ground station services and improved portability across heterogeneous installations. This capability, combined with selective customization through virtual machine technology, allowed us to deliver "just in time" ground stations for QuakeSat-1 at a fraction of the price of current commodity solutions. This decomposition is also informed by principles of robust system design. Thus, our ground station reference implementation called Mercury was a candidate for recursive recovery (RR), a high availability technique whose effectiveness in reducing recovery time has been demonstrated on research prototypes of Internet server systems. Augmenting Mercury to implement RR reduced recovery time of typical ground station software failures by a factor of four, dropping recovery time to within the "window of recovery" and effectively eliminating the adverse effects of these failures. Since the time of failures cannot be predicted, RR allowed us to mitigate the effects of the failures and greatly reduce their potential impact on ground station operations. Our ground station architecture harnessed the benefits of COTS components, including rapid prototyping and deployment, while overcoming the challenges of COTS reliability and mission

  19. A New Method of Desired Gait Synthesis for Biped Walking Robot Based on Ground Reaction Force

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    A new method of desired gait synthesis for biped walking robot based on the ground reaction force was proposed. The relation between the ground reaction force and joint motion is derived using the D'Almbert principle. In view of dynamic walking with high stability, the ZMP(Zero Moment Point)stability criterion must be considered in the desired gait synthesis. After that, the joint trajectories of biped walking robot are decided by substituting the ground reaction force into the aforesaid relation based on the ZMP criterion. The trajectory of desired ZMP is determined by a fuzzy logic based upon the body posture of biped walking robot. The proposed scheme is simulated and experimented on a 10 degree of freedom biped walking