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Sample records for airborne sar system

  1. Processor architecture for airborne SAR systems

    NASA Technical Reports Server (NTRS)

    Glass, C. M.

    1983-01-01

    Digital processors for spaceborne imaging radars and application of the technology developed for airborne SAR systems are considered. Transferring algorithms and implementation techniques from airborne to spaceborne SAR processors offers obvious advantages. The following topics are discussed: (1) a quantification of the differences in processing algorithms for airborne and spaceborne SARs; and (2) an overview of three processors for airborne SAR systems.

  2. Preliminary results of the LLNL airborne experimental test-bed SAR system

    SciTech Connect

    Miller, M.G.; Mullenhoff, C.J.; Kiefer, R.D.; Brase, J.M.; Wieting, M.G.; Berry, G.L.; Jones, H.E.

    1996-01-16

    The Imaging and Detection Program (IDP) within Laser Programs at Lawrence Livermore National Laboratory (LLNL) in cooperation with the Hughes Aircraft Company has developed a versatile, high performance, airborne experimental test-bed (AETB) capability. The test-bed has been developed for a wide range of research and development experimental applications including radar and radiometry plus, with additional aircraft modifications, optical systems. The airborne test-bed capability has been developed within a Douglas EA-3B Skywarrior jet aircraft provided and flown by Hughes Aircraft Company. The current test-bed payload consists of an X-band radar system, a high-speed data acquisition, and a real-time processing capability. The medium power radar system is configured to operate in a high resolution, synthetic aperture radar (SAR) mode and is highly configurable in terms of waveforrns, PRF, bandwidth, etc. Antennas are mounted on a 2-axis gimbal in the belly radome of the aircraft which provides pointing and stabilization. Aircraft position and antenna attitude are derived from a dedicated navigational system and provided to the real-time SAR image processor for instant image reconstruction and analysis. This paper presents a further description of the test-bed and payload subsystems plus preliminary results of SAR imagery.

  3. The NASA/JPL multifrequency, multipolarisation airborne SAR system

    NASA Technical Reports Server (NTRS)

    Held, D. N.; Brown, W. E.; Freeman, A.; Klein, J. D.; Zebker, H. A.; Sato, T.; Miller, T.; Nguyen, Q.; Lou, Y.

    1988-01-01

    Polarimetric synthetic aperture radars, operating at L-, C- and P-band, were designed to replace and upgrade a system destroyed in an aircraft accident. Ground and flight tests were conducted, and the radar was flown over a calibration site in a sequence of experiments designed to calibrate the system. The radar also took part in science campaigns.

  4. TELAER: a multi-mode/multi-antenna interferometric airborne SAR system

    NASA Astrophysics Data System (ADS)

    Perna, Stefano; Amaral, Tiago; Berardino, Paolo; Esposito, Carmen; Jackson, Giuseppe; Pauciullo, Antonio; Vaz Junior, Eurico; Wimmer, Christian; Lanari, Riccardo

    2014-05-01

    The present contribution is aimed at showing the capabilities of the TELAER airborne Synthetic Aperture Radar (SAR) system recently upgraded to the interferometric mode [1]. TELAER is an Italian airborne X-Band SAR system, mounted onboard a LearJet 35A aircraft. Originally equipped with a single TX/RX antenna, it now operates in single-pass interferometric mode thanks to a system upgrading [1] funded by the Italian National Research Council (CNR), via the Italian Ministry of Education, Universities and Research (MIUR), in the framework of a cooperation between CNR and the Italian Agency for Agriculture Subsidy Payments (AGEA). In the frame of such cooperation, CNR has entrusted the Institute for Electromagnetic Sensing of the Environment (IREA) for managing all the activities, included the final flight tests, related to the system upgrading. According to such an upgrading, two additional receiving X-band antennas have been installed in order to allow, simultaneously, single-pass Across-Track and Along-Track interferometry [1]. More specifically, the three antennas are now installed in such a way to produce three different across-track baselines and two different along-track baselines. Moreover, in the frame of the same system upgrading, it has been mounted onboard the Learjet an accurate embedded Global Navigation Satellite System and Inertial Measurement Unit equipment. This allows precise measurement of the tracks described by the SAR antennas during the flight, in order to accurately implement Motion Compensation (MOCO) algorithms [2] during the image formation (focusing) step. It is worth remarking that the TELAER system upgraded to the interferometric mode is very flexible, since the user can set different operational modes characterized by different geometric resolutions and range swaths. In particular, it is possible to reach up to 0.5 m of resolution with a range swath of 2km; conversely, it is possible to enlarge the range swath up to 10 km at expenses of

  5. UAVSAR: A New NASA Airborne SAR System for Science and Technology Research

    NASA Technical Reports Server (NTRS)

    Rosen, Paul A.; Hensley, Scott; Wheeler, Kevin; Sadowy, Greg; Miller, Tim; Shaffer, Scott; Muellerschoen, Ron; Jones, Cathleen; Zebker, Howard; Madsen, Soren

    2006-01-01

    NASA's Jet Propulsion Laboratory is currently building a reconfigurable, polarimetric L-band synthetic aperture radar (SAR), specifically designed to acquire airborne repeat track SAR data for differential interferometric measurements. Differentian interferometry can provide key deformation measurements, important for studies of earthquakes, volcanoes and other dynamically changing phenomena. Using precision real-time GPS and a sensor controlled flight management system, the system will be able to fly predefined paths with great precision. The expected performance of the flight control system will constrain the flight path to be within a 10 m diameter tube about the desired flight track. The radar will be designed to be operable on a UAV (Unpiloted Aria1 Vehicle) but will initially be demonstrated on a NASA Gulfstream III. The radar will be fully polarimetric, with a range bandwidth of 80 MHz (2 m range resolution), and will support a 16 km range swath. The antenna will be electronically steered along track to assure that the antenna beam can be directed independently, regardless of the wind direction and speed. Other features supported by the antenna include elevation monopulse and pulse-to-pulse re-steering capabilities that will enable some novel modes of operation. The system will nominally operate at 45,000 ft (13800 m). The program began as an Instrument Incubator Project (IIP) funded by NASA Earth Science and Technology Office (ESTO).

  6. MAPSAR Image Simulation Based on L-band Polarimetric Data from the SAR-R99B Airborne Sensor (SIVAM System)

    PubMed Central

    Mura, José Claudio; Paradella, Waldir Renato; Dutra, Luciano Vieira; dos Santos, João Roberto; Rudorff, Bernardo Friedrich Theodor; de Miranda, Fernando Pellon; da Silva, Mario Marcos Quintino; da Silva, Wagner Fernando

    2009-01-01

    This paper describes the methodology applied to generate simulated multipolarized L-band SAR images of the MAPSAR (Multi-Application Purpose SAR) satellite from the airborne SAR R99B sensor (SIVAM System). MAPSAR is a feasibility study conducted by INPE (National Institute for Space Research) and DLR (German Aerospace Center) targeting a satellite L-band SAR innovative mission for assessment, management and monitoring of natural resources. Examples of simulated products and their applications are briefly discussed. PMID:22389590

  7. Forest Information Extraction from Airborne P-Band PolSAR and X-Band InSAR Data

    NASA Astrophysics Data System (ADS)

    Chen, Erxue; Li, Zengyuan; Tian, Xin; Feng, Qi; Zhao, Lei; Li, Lan; Hong, Wen; Pottier, Eric

    2014-11-01

    The key research progress of forest information extraction from high resolution PolSAR/InSAR data acquired by one China airborne system were summarized. Firstly, the airborne campaign activities carried out in 2012, 2013, in China were introduced. Secondly, the key SAR/InSAR data processing steps, such as, InSAR processing, SAR image geocoding terrain correction (GTC),the methods used to derive forest height, forest above ground biomass (AGB)from LiDAR, CCD and ground plots data were described. Finally, we introduced the forest information extraction methods and preliminary validation results from P-band PolSAR data and single baseline X-band InSAR data: (1)Forest height inversion using high resolution X-band InSAR data;(2) Forest AGB estimation using P-band PolSAR data; (3) Forest land cover types classification using PolSAR data.

  8. Forest Information Extraction from Airborne P-Band PolSAR and X-Band InSAR Data

    NASA Astrophysics Data System (ADS)

    Chen, Erxue; Li, Zengyuan; Tian, Xin; Feng, Qi; Zhao, Lei; Li, Lan; Hong, Wen; Pottier, Eric

    2014-11-01

    The key research progress of forest information extraction from high resolution PolSAR/InSAR data acquired by one China airborne system were summarized. Firstly, the airborne campaign activities carried out in 2012, 2013, in China were introduced. Secondly, the key SAR/InSAR data processing steps, such as, InSAR processing, SAR image geocoding terrain correction (GTC), the methods used to derive forest height, forest above ground biomass (AGB) from LiDAR, CCD and ground plots data were described. Finally, we introduced the forest information extraction methods and preliminary validation results from P-band PolSAR data and single baseline X-band InSAR data: (1) Forest height inversion using high resolution X-band InSAR data; (2) Forest AGB estimation using P-band PolSAR data; (3) Forest land cover types classification using PolSAR data.

  9. First Results from an Airborne Ka-Band SAR Using SweepSAR and Digital Beamforming

    NASA Technical Reports Server (NTRS)

    Sadowy, Gregory A.; Ghaemi, Hirad; Hensley, Scott C.

    2012-01-01

    SweepSAR is a wide-swath synthetic aperture radar technique that is being studied for application on the future Earth science radar missions. This paper describes the design of an airborne radar demonstration that simulates an 11-m L-band (1.2-1.3 GHz) reflector geometry at Ka-band (35.6 GHz) using a 40-cm reflector. The Ka-band SweepSAR Demonstration system was flown on the NASA DC-8 airborne laboratory and used to study engineering performance trades and array calibration for SweepSAR configurations. We present an instrument and experiment overview, instrument calibration and first results.

  10. ISRO's dual frequency airborne SAR pre-cursor to NISAR

    NASA Astrophysics Data System (ADS)

    Ramanujam, V. Manavala; Suneela, T. J. V. D.; Bhan, Rakesh

    2016-05-01

    The Indian Space Research Organisation (ISRO) and the National Aeronautics and Space Administration (NASA) have jointly embarked on NASA-ISRO Synthetic Aperture Radar (NISAR) operating in L-band and S-band, which will map Earth's surface every 12 days. As a pre-cursor to the NISAR mission, ISRO is planning an airborne SAR (L&S band) which will deliver NISAR analogue data products to the science community. ISRO will develop all the hardware with the aim of adhering to system design aspects of NISAR to the maximum extent possible. It is a fully polarimetric stripmap SAR and can be operated in single, dual, compact, quasi-quad and full polarimetry modes. It has wide incidence angle coverage from 24°-77° with swath coverage from 5.5km to 15 km. Apart from simultaneous imaging operations, this system can also operate in standalone L/S SAR modes. This system is planned to operate from an aircraft platform with nominal altitude of 8000meters. Antenna for this SAR will be rigidly mounted to the aircraft, whereas, motion compensation will be implemented in the software processor to generate data products. Data products for this airborne SAR will be generated in slant & ground range azimuth dimension and geocoded in HDF5/Geotiff formats. This airborne SAR will help to prepare the Indian scientific community for optimum utilization of NISAR data. In-order to collect useful science data, airborne campaigns are planned from end of 2016 onwards.

  11. Extracting Tree Height from Repeat-Pass PolInSAR Data : Experiments with JPL and ESA Airborne Systems

    NASA Technical Reports Server (NTRS)

    Lavalle, Marco; Ahmed, Razi; Neumann, Maxim; Hensley, Scott

    2013-01-01

    In this paper we present our latest developments and experiments with the random-motion-over-ground (RMoG) model used to extract canopy height and other important forest parameters from repeat-pass polarimetricinterferometric SAR (Pol-InSAR) data. More specifically, we summarize the key features of the RMoG model in contrast with the random-volume-over-ground (RVoG) model, describe in detail a possible inversion scheme for the RMoG model and illustrate the results of the RMoG inversion using airborne data collected by the Jet Propulsion Laboratory (JPL) and the European Space Agency (ESA).

  12. Airborne SAR imagery to support hydraulic models

    NASA Astrophysics Data System (ADS)

    Castiglioni, S.

    2009-04-01

    Satellite images and airborne SAR (Synthetic Aperture Radar) imagery are increasingly widespread and they are effective tools for measuring the size of flood events and for assessment of damage. The Hurricane Katrina disaster and the tsunami catastrophe in Indian Ocean countries are two recent and sadly famous examples. Moreover, as well known, the inundation maps can be used as tools to calibrate and validate hydraulic model (e.g. Horritt et al., Hydrological Processes, 2007). We carry out an application of a 1D hydraulic model coupled with a high resolution DTM for predicting the flood inundation processes. The study area is a 16 km reach of the River Severn, in west-central England, for which, four maps of inundated areas, obtained through airborne SAR images, and hydrometric data are available. The inundation maps are used for the calibration/validation of a 1D hydraulic model through a comparison between airborne SAR images and the results of hydraulic simulations. The results confirm the usefulness of inundation maps as hydraulic modelling tools and, moreover, show that 1D hydraulic model can be effectively used when coupled with high resolution topographic information.

  13. Cross-calibration between airborne SAR sensors

    NASA Technical Reports Server (NTRS)

    Zink, Manfred; Olivier, Philippe; Freeman, Anthony

    1993-01-01

    As Synthetic Aperture Radar (SAR) system performance and experience in SAR signature evaluation increase, quantitative analysis becomes more and more important. Such analyses require an absolute radiometric calibration of the complete SAR system. To keep the expenditure on calibration of future multichannel and multisensor remote sensing systems (e.g., X-SAR/SIR-C) within a tolerable level, data from different tracks and different sensors (channels) must be cross calibrated. The 1989 joint E-SAR/DC-8 SAR calibration campaign gave a first opportunity for such an experiment, including cross sensor and cross track calibration. A basic requirement for successful cross calibration is the stability of the SAR systems. The calibration parameters derived from different tracks and the polarimetric properties of the uncalibrated data are used to describe this stability. Quality criteria for a successful cross calibration are the agreement of alpha degree values and the consistency of radar cross sections of equally sized corner reflectors. Channel imbalance and cross talk provide additional quality in case of the polarimetric DC-8 SAR.

  14. Hybrid space-airborne bistatic SAR geometric resolutions

    NASA Astrophysics Data System (ADS)

    Moccia, Antonio; Renga, Alfredo

    2009-09-01

    Performance analysis of Bistatic Synthetic Aperture Radar (SAR) characterized by arbitrary geometric configurations is usually complex and time-consuming since system impulse response has to be evaluated by bistatic SAR processing. This approach does not allow derivation of general equations regulating the behaviour of image resolutions with varying the observation geometry. It is well known that for an arbitrary configuration of bistatic SAR there are not perpendicular range and azimuth directions, but the capability to produce an image is not prevented as it depends only on the possibility to generate image pixels from time delay and Doppler measurements. However, even if separately range and Doppler resolutions are good, bistatic SAR geometries can exist in which imaging capabilities are very poor when range and Doppler directions become locally parallel. The present paper aims to derive analytical tools for calculating the geometric resolutions of arbitrary configuration of bistatic SAR. The method has been applied to a hybrid bistatic Synthetic Aperture Radar formed by a spaceborne illuminator and a receiving-only airborne forward-looking Synthetic Aperture Radar (F-SAR). It can take advantage of the spaceborne illuminator to dodge the limitations of monostatic FSAR. Basic modeling and best illumination conditions have been detailed in the paper.

  15. Indoor experimental facility for airborne synthetic aperture radar (SAR) configurations - rail-SAR

    NASA Astrophysics Data System (ADS)

    Kirose, Getachew; Phelan, Brian R.; Sherbondy, Kelly D.; Ranney, Kenneth I.; Koenig, Francois; Narayanan, Ram M.

    2014-05-01

    The Army Research Laboratory (ARL) is developing an indoor experimental facility to evaluate and assess airborne synthetic-aperture-radar-(SAR)-based detection capabilities. The rail-SAR is located in a multi-use facility that also provides a base for research and development in the area of autonomous robotic navigation. Radar explosive hazard detection is one key sensordevelopment area to be investigated at this indoor facility. In particular, the mostly wooden, multi-story building houses a two (2) story housing structure and an open area built over a large sandbox. The housing structure includes reconfigurable indoor walls which enable the realization of multiple See-Through-The-Wall (STTW) scenarios. The open sandbox, on the other hand, allows for surface and buried explosive hazard scenarios. The indoor facility is not rated for true explosive hazard materials so all targets will need to be inert and contain surrogate explosive fills. In this paper we discuss the current system status and describe data collection exercises conducted using canonical targets and frequencies that may be of interest to designers of ultra-wideband (UWB) airborne, ground penetrating SAR systems. A bi-static antenna configuration will be used to investigate the effects of varying airborne SAR parameters such as depression angle, bandwidth, and integration angle, for various target types and deployment scenarios. Canonical targets data were used to evaluate overall facility capabilities and limitations. These data is analyzed and summarized for future evaluations. Finally, processing techniques for dealing with RF multi-path and RFI due to operating inside the indoor facility are described in detail. Discussion of this facility and its capabilities and limitations will provide the explosive hazard community with a great airborne platform asset for sensor to target assessment.

  16. Forest Height and Ground Topography at L-Band from an Experimental Single-Pass Airborne Pol-InSAR System

    NASA Astrophysics Data System (ADS)

    Mercer, B.; Zhang, Q.; Schwaebisch, M.; Denbina, M.; Cloude, S.

    2009-04-01

    Many applications require bare-earth Digital Terrain Models (DTMs) in the presence of forest canopy. L-Band is an attractive candidate, but the derived interferometric phase represents a combination of ground and volume scattering contributions from the canopy above. The use of PolInSAR techniques, and the Random Volume Over Ground (RVOG) Model has had considerable success in model inversion studies where the objective has been to extract tree height. A major problem for the robust application of this technique is the presence of temporal decorrelation, caused by the use of repeat-pass interferometry. In this paper we will present the current results of canopy height and DTM estimation in forested areas using an experimental airborne, single-pass, L-Band PolInSAR system for which temporal decorrelation is not an issue.

  17. Airborne X-band SAR tomography for forest volumes

    NASA Astrophysics Data System (ADS)

    Muirhead, Fiona; Woodhouse, Iain H.; Mulgrew, Bernard

    2016-10-01

    We evaluate the usefulness of X-band, airborne (helicopter) data for tomography over forestry regions and discuss the use of compressive sensing algorithms to aid X-band airborne tomography. This work examines if there is any information that can be gained from forest volumes when analysing forestry sites using X-band data. To do so, different forest scenarios were simulated and a fast SAR simulator was used to model airborne multipass SAR data, at X-band, with parameters based on Leonardo's PicoSAR instrument. Model simulations considered varying factors that affect the height determination when using tomography. The main parameters that are considered here are: motion errors of the platform, the spacing of the flight paths, the resolution of the SAR images and plant life being present under the canopy (an understory). It was found that residual motion errors from the airborne platform cause the largest error in the tomographic profile.

  18. Initial assessment of an airborne Ku-band polarimetric SAR.

    SciTech Connect

    Raynal, Ann Marie; Doerry, Armin Walter

    2013-02-01

    Polarimetric synthetic aperture radar (SAR) has been used for a variety of dual-use research applications since the 1940s. By measuring the direction of the electric field vector from radar echoes, polarimetry may enhance an analysts understanding of scattering effects for both earth monitoring and tactical surveillance missions. Polarimetry may provide insight into surface types, materials, or orientations for natural and man-made targets. Polarimetric measurements may also be used to enhance the contrast between scattering surfaces such as man-made objects and their surroundings. This report represents an initial assessment of the utility of, and applications for, polarimetric SAR at Ku-band for airborne or unmanned aerial systems.

  19. Ground moving target indication via multi-channel airborne SAR

    NASA Astrophysics Data System (ADS)

    Vu, Duc; Guo, Bin; Xu, Luzhou; Li, Jian

    2011-06-01

    We consider moving target detection and velocity estimation for multi-channel synthetic aperture radar (SAR) based ground moving target indication (GMTI). Via forming velocity versus cross-range images, we show that small moving targets can be detected even in the presence of strong stationary ground clutter. Furthermore, the velocities of the moving targets can be estimated, and the misplaced moving targets can be placed back to their original locations based on the estimated velocities. An iterative adaptive approach (IAA), which is robust and user parameter free, is used to form velocity versus cross-range images for each range bin of interest. Moreover, we discuss calibration techniques to combat near-field coupling problems encountered in practical systems. Furthermore, we present a sparse signal recovery approach for stationary clutter cancellation. We conclude by demonstrating the effectiveness of our approaches by using the Air Force Research Laboratory (AFRL) publicly-released Gotcha airborne SAR based GMTI data set.

  20. Mapping Slumgullion Landslide in Colorado, USA Using Airborne Repeat-Pass InSAR

    NASA Astrophysics Data System (ADS)

    Lee, H.; Shrestha, R. L.; Carter, W. E.; Glennie, C. L.; Wang, G.; Lu, Z.; Fernandez-Diaz, J. C.; Cao, N.; Zaugg, E.

    2015-12-01

    Interferometric Synthetic Aperture Radar (InSAR) uses two or more SAR images over the same area to determine landscape topography or ground deformation. An interferogram, generated by the phase components of two coherent SAR images, depicts range changes between the radar and the ground resolution elements, and can be used to derive both landscape topography and subtle changes in surface elevation. However, spaceborne repeat-pass interferometry has two main drawbacks: effects due to differences in atmospheric temperature, pressure, and water vapour at two observation times, and loss of coherence due to long spatial and temporal baselines between observations. Airborne repeat-pass interferometry does not suffer from these drawbacks. The atmospheric effect in case of airborne DInSAR becomes negligible due to smaller swath coverage, and the coherence can be maintained by using smaller spatial and temporal baselines. However, the main technical limitation concerning airborne DInSAR is the need of precise motion compensation with an accurate navigation system to correct for the significant phase errors due to typical flight instability from air turbulence. Here, we present results from a pilot study conducted on July 2015 using both X-band and L-band SlimSAR airborne system over the Slumgullion landslide in Colorado in order to (1) acquire the differential interferograms from the airborne platform, (2) understand their source of errors, and (3) pave a way to improve the precision of the derived surface deformation. The landslide movement estimated from airborne DInSAR is also compared with coincident GPS, terrestrial laser scanning (TLS), airborne LiDAR, and spaceborne DInSAR measurements using COSMO-SkyMed images. The airborne DInSAR system has a potential to provide time-transient variability in land surface topography with high-precision and high-resolution, and provide researchers with greater flexibility in selecting the temporal and spatial baselines of the data

  1. An Integrated Navigation System using GPS Carrier Phase for Real-Time Airborne Synthetic Aperture Radar (SAR)

    SciTech Connect

    Fellerhoff, J. Rick; Kim, Theodore J.; Kohler, Stewart M.

    1999-06-24

    A Synthetic Aperture Radar (SAR) requires accu- rate measurement of the motion of the imaging plat- form to produce well-focused images with minimal absolute position error. The motion measurement (MoMeas) system consists of a inertial measurement unit (IMU) and a P-code GPS receiver that outputs corrected ephemeris, L1 & L2 pseudoranges, and L1 & L2 carrier phase measurements. The unknown initial carrier phase biases to the GPS satellites are modeled as states in an extended Kalman filter and the resulting integrated navigation solution has po- sition errors that change slowly with time. Position error drifts less than 1- cm/sec have been measured from the SAR imagery for various length apertures.

  2. First Results from an Airborne Ka-band SAR Using SweepSAR and Digital Beamforming

    NASA Technical Reports Server (NTRS)

    Sadowy, Gregory; Ghaemi, Hirad; Hensley, Scott

    2012-01-01

    NASA/JPL has developed SweepSAR technique that breaks typical Synthetic Aperture Radar (SAR) trade space using time-dependent multi-beam DBF on receive. Developing SweepSAR implementation using array-fed reflector for proposed DESDynI Earth Radar Mission concept. Performed first-of-a-kind airborne demonstration of the SweepSAR concept at Ka-band (35.6 GHz). Validated calibration and antenna pattern data sufficient for beam forming in elevation. (1) Provides validation evidence that the proposed Deformation Ecosystem Structure Dynamics of Ice (DESDynI) SAR architecture is sound. (2) Functions well even with large variations in receiver gain / phase. Future plans include using prototype DESDynI SAR digital flight hardware to do the beam forming in real-time onboard the aircraft.

  3. Ka-band Digitally Beamformed Airborne Radar Using SweepSAR Technique

    NASA Technical Reports Server (NTRS)

    Sadowy, Gregory A.; Chuang, Chung-Lun; Ghaemi, Hirad; Heavey, Brandon A.; Lin, Lung-Sheng S.; Quaddus, Momin

    2012-01-01

    A paper describes a frequency-scaled SweepSAR demonstration that operates at Ka-Band (35.6 GHz), and closely approximates the DESDynl mission antenna geometry, scaled by 28. The concept relies on the SweepSAR measurement technique. An array of digital receivers captures waveforms from a multiplicity of elements. These are combined using digital beamforming in elevation and SAR processing to produce imagery. Ka-band (35.6 GHz) airborne SweepSAR using array-fed reflector and digital beamforming features eight simultaneous receive beams generated by a 40-cm offset-fed reflector and eight-element active array feed, and eight digital receiver channels with all raw data recorded and later used for beamforming. Illumination of the swath is accomplished using a slotted-waveguide antenna radiating 250 W peak power. This experiment has been used to demonstrate digital beamforming SweepSAR systems.

  4. Using airborne and satellite SAR for wake mapping offshore

    NASA Astrophysics Data System (ADS)

    Christiansen, Merete B.; Hasager, Charlotte B.

    2006-09-01

    Offshore wind energy is progressing rapidly around Europe. One of the latest initiatives is the installation of multiple wind farms in clusters to share cables and maintenance costs and to fully exploit premium wind resource sites. For siting of multiple nearby wind farms, the wind turbine wake effect must be considered. Synthetic aperture radar (SAR) is an imaging remote sensing technique which offers a unique opportunity to describe spatial variations of wind speed offshore. For the first time an airborne SAR instrument was used for data acquisition over a large offshore wind farm. The aim was to identify the turbine wake effect from SAR-derived wind speed maps as a downstream region of reduced wind speed. The aircraft SAR campaign was conducted on 12 October 2003 over the wind farm at Horns Rev in the North Sea. Nearly simultaneous measurements were acquired over the area by the SAR on board the ERS-2 satellite. In addition, meteorological data were collected. Both aircraft and satellite SAR-derived wind speed maps showed significant velocity deficits downstream of the wind farm. Wind speed maps retrieved from aircraft SAR suggested deficits of up to 20% downstream of the last turbine, whereas satellite SAR-derived maps showed deficits of the order of 10%. The difference originated partly from the two different reference methods used for normalization of measured wind speeds. The detected region of reduced wind speed had the same width as the wind turbine array, indicating a low degree of horizontal wake dispersion. The downstream wake extent was approximately 10 km, which corresponds well with results from previous studies and with wake model predictions. Copyright

  5. First Demonstration of Agriculture Height Retrieval with PolInSAR Airborne Data

    NASA Astrophysics Data System (ADS)

    Lopez-Sanchez, Juan M.; Ballester-Berman, J. David; Hajnsek, Irena

    2011-03-01

    A set of three quad-pol images acquired at L-band in interferometric repeat-pass mode by DLR with the E-SAR system, in parallel with the AgriSAR2006 campaign, have been used to provide a first demonstration with airborne data of the retrieval of vegetation height from agricultural crops by means of PolInSAR based techniques.We have obtained accurate estimates of vegetation height over winter rape and maize fields, when compared with the availabe ground measurements. The same procedure yields a clear overestimation and larger variance over wheat fields.Results demonstrate that, although the frequency band is low, the model employed for the inversion is very simple, and the backscattered signal contains an important contribution from the ground, the volume information provided by interferometry is present and enables the application of PolInSAR-based retrieval approaches for agriculture monitoring practices.

  6. Hierarchical classifier design for airborne SAR images of ships

    NASA Astrophysics Data System (ADS)

    Gagnon, Langis; Klepko, Robert

    1998-09-01

    We report about a hierarchical design for extracting ship features and recognizing ships from SAR images, and which will eventually feed a multisensor data fusion system for airborne surveillance. The target is segmented from the image background using directional thresholding and region merging processes. Ship end-points are then identified through a ship centerline detection performed with a Hough transform. A ship length estimate is calculated assuming that the ship heading and/or the cross-range resolution are known. A high-level ship classification identifies whether the target belongs to Line (mainly combatant military ships) or Merchant ship categories. Category discrimination is based on the radar scatterers' distribution in 9 ship sections along the ship's range profile. A 3-layer neural network has been trained on simulated scatterers distributions and supervised by a rule- based expert system to perform this task. The NN 'smoothes out' the rules and the confidence levels on the category declaration. Line ship type (Frigate, Destroyer, Cruiser, Battleship, Aircraft Carrier) is then estimated using a Bayes classifier based on the ship length. Classifier performances using simulated images are presented.

  7. RADI's Airborne X-SAR with High Resolution: Performance, Characterization and Verification

    NASA Astrophysics Data System (ADS)

    Shen, T.; Li, J.; Wang, Z. R.; Huang, L.

    2016-11-01

    X-SAR is an airborne multi-mode synthetic aperture radar (SAR) system with high- resolution, interferometer and full-polarization, developed by the Institute of Remote Sensing and Digital Earth (RADI), Chinese Academy of Sciences (CAS), funded by the CAS Large Research Infrastructures. Since 2009, the first developed stage of X-SAR system was successfully implemented to an operational SAR with high resolution (up to 0.5 meter). In May 2013, the imaging verification on flights test was carried out. The data calibration on the laboratory measurements were completed at the end of 2015. Many valuable results of imaging verification and data calibration have emphasized the quantitative microwave measurement capabilities. This paper presents the results of X-SAR system performance, characterization, optimization, and verification as carried out during the flight trials and laboratory measurement. The system performance and calibration parameters are presented such as transmitter amplitude accuracy, phase noise, system gain change with temperature variation, long-term radiometric stability. The imaging verification of the key performance parameters is discussed, including target-response function, target pairs discrimination, image noise and radiometric resolution. The example imagery of radiometric enhanced products for intensity change detection is also described.

  8. Tomographic Imaging of a Forested Area By Airborne Multi-Baseline P-Band SAR.

    PubMed

    Frey, Othmar; Morsdorf, Felix; Meier, Erich

    2008-09-24

    In recent years, various attempts have been undertaken to obtain information about the structure of forested areas from multi-baseline synthetic aperture radar data. Tomographic processing of such data has been demonstrated for airborne L-band data but the quality of the focused tomographic images is limited by several factors. In particular, the common Fourierbased focusing methods are susceptible to irregular and sparse sampling, two problems, that are unavoidable in case of multi-pass, multi-baseline SAR data acquired by an airborne system. In this paper, a tomographic focusing method based on the time-domain back-projection algorithm is proposed, which maintains the geometric relationship between the original sensor positions and the imaged target and is therefore able to cope with irregular sampling without introducing any approximations with respect to the geometry. The tomographic focusing quality is assessed by analysing the impulse response of simulated point targets and an in-scene corner reflector. And, in particular, several tomographic slices of a volume representing a forested area are given. The respective P-band tomographic data set consisting of eleven flight tracks has been acquired by the airborne E-SAR sensor of the German Aerospace Center (DLR).

  9. Tomographic Imaging of a Forested Area By Airborne Multi-Baseline P-Band SAR

    PubMed Central

    Frey, Othmar; Morsdorf, Felix; Meier, Erich

    2008-01-01

    In recent years, various attempts have been undertaken to obtain information about the structure of forested areas from multi-baseline synthetic aperture radar data. Tomographic processing of such data has been demonstrated for airborne L-band data but the quality of the focused tomographic images is limited by several factors. In particular, the common Fourier-based focusing methods are susceptible to irregular and sparse sampling, two problems, that are unavoidable in case of multi-pass, multi-baseline SAR data acquired by an airborne system. In this paper, a tomographic focusing method based on the time-domain back-projection algorithm is proposed, which maintains the geometric relationship between the original sensor positions and the imaged target and is therefore able to cope with irregular sampling without introducing any approximations with respect to the geometry. The tomographic focusing quality is assessed by analysing the impulse response of simulated point targets and an in-scene corner reflector. And, in particular, several tomographic slices of a volume representing a forested area are given. The respective P-band tomographic data set consisting of eleven flight tracks has been acquired by the airborne E-SAR sensor of the German Aerospace Center (DLR). PMID:27873847

  10. Classification And Monitoring Of Salt Marsh Habitats With Multi-Polarimetric Airborne SAR

    NASA Astrophysics Data System (ADS)

    van Beijma, Sybrand; Comber, Alexis; Lamb, Alistair

    2013-12-01

    Within the Copernicus programme there is much interest in the ability of remote sensing technology to deliver operational solutions to many areas of life including environmental management. This paper describes research focused on the application of Earth Observation for Integrated Coastal Zone Management. The main topic of this research is to explore to which extent salt marsh vegetation habitats can be identified from polarimetric SAR remotely sensed data. Multi- frequency, multi-polarimetric SAR images from airborne (S- and X-Band quad-polarimetric from the Astrium airborne SAR Demonstrator) is used to examine salt marsh habitat classification potential in the Llanrhidian salt marshes in South Wales, UK. This is achieved by (1) using both supervised and unsupervised classification routines, using several polarimetric SAR data layers as backscatter intensity, band ratios and polarimetric decomposition products, and by (2) statistical analysis by regression of these different SAR data layers and botanical parameters acquired from recent ecological fieldwork.

  11. Post disaster monitoring for the Great East Japan Earthquake with a new L-band airborne SAR "Pi-SAR-L2"

    NASA Astrophysics Data System (ADS)

    Kawano, Noriyuki

    2013-04-01

    A new L-band airborne SAR, Polarimetric and interferometry Synthetic Aperture Radar with L-band type-2 (Pi-SAR-L2) was developed in April 2012 by Japan Aerospace exploration Agency(JAXA). Pi-SAR-L2 employs a L-band with a band width of 85 MHz (1,215 - 1,300 MHz) with a peak power of 3.5 kW boarded on the Galfstream II. Pi-SAR-L2 conducted its first acquisitions for calibrations and validations over Tomakomai, Hokkaido, where is a test site with some corner reflectors in April 2012. The Great East Japan Earthquake with a magnitude 9.0 occurred at 14:46 on 11 Mar. 2011 and terribly big Tsunami attacked Tohoku district after the earthquake. The tsunami caused huge damage along its coast in Touhoku. Pi-SAR-L2 acquired these post disaster regions in Fukushima and Miyagi Prefectures along the coast on the way to Hokkaido in April 2012, some region still remain flooded area and debris caused by Tsumani. We will present Pi-SAR-L2 systems and specifications, and discuss monitoring these damages.

  12. EcoSAR: NASA's P-band fully polarimetric single pass interferometric airborne radar

    NASA Astrophysics Data System (ADS)

    Osmanoglu, B.; Rincon, R. F.; Fatoyinbo, T. E.; Lee, S. K.; Sun, G.; Daniyan, O.; Harcum, M. E.

    2014-12-01

    EcoSAR is a new airborne synthetic aperture radar imaging system, developed at the NASA Goddard Space Flight Center. It is a P-band sensor that employs a non-conventional and innovative design. The EcoSAR system was designed as a multi-disciplinary instrument to image the 3-dimensional surface of the earth from a single pass platform with two antennas. EcoSAR's principal mission is to penetrate the forest canopy to return vital information about the canopy structure and estimate biomass. With a maximum bandwidth of 200 MHz in H and 120 MHz in V polarizations it can provide sub-meter resolution imagery of the study area. EcoSAR's dual antenna, 32 transmit and receive channel architecture provides a test-bed for developing new algorithms in InSAR data processing such as single pass interferometry, full polarimetry, post-processing synthesis of multiple beams, simultaneous measurement over both sides of the flight track, selectable resolution and variable incidence angle. The flexible architecture of EcoSAR will create new opportunities in radar remote sensing of forest biomass, permafrost active layer thickness, and topography mapping. EcoSAR's first test flight occurred between March 27th and April 1st, 2014 over the Andros Island in Bahamas and Corcovado and La Selva National Parks in Costa Rica. The 32 channel radar system collected about 6 TB of radar data in about 12 hours of data collection. Due to the existence of radio and TV communications in the operational frequency band, acquired data contains strong radar frequency interference, which had to be removed prior to beamforming and focusing. Precise locations of the antennas are tracked using high-rate GPS and inertial navigation units, which provide necessary information for accurate processing of the imagery. In this presentation we will present preliminary imagery collected during the test campaign, show examples of simultaneous dual track imaging, as well as a single pass interferogram. The

  13. Estimation of Snow Thickness on Sea Ice and Lake Ice Using Airborne SnowSAR Data

    NASA Astrophysics Data System (ADS)

    Veijola, Katriina; Makynen, Marko; Lemmetyinen, Juha; Praks, Jaan

    2016-08-01

    Currently, snow thickness on sea ice is operationally estimated using microwave radiometer data. However, the estimates are hampered by the inherent coarse spatial resolution of passive microwave sensors. Successful application of SAR imagery for snow thickness estimation has the potential of providing estimates of snow thickness with much finer spatial resolution.In this study, we concentrate on assessing the capability of X- and Ku-band SAR backscattering to estimate snow thickness on sea and lake ice. Co- and cross -polarized X- and Ku-band SAR backscattering data, acquired with the ESA airborne SnowSAR sensor, are applied. The SAR data acquisition and co-incident in-situ measurements were conducted in Finland in the winter of 2012 over sea ice and lake ice test sites.Our analysis shows which frequency and polarization combinations have best sensitivity to snow thickness on sea and lake ice and in deep discussion provides plausible ways to improve the results.

  14. A comparison of airborne GEMS/SAR with satellite-borne Seasat/SAR radar imagery - The value of archived multiple data sets

    NASA Technical Reports Server (NTRS)

    Hanson, Bradford C.; Dellwig, Louis F.

    1988-01-01

    In a study concerning the value of using radar imagery from systems with diverse parameters, X-band images of the Northern Louisiana Salt dome area generated by the airborne Goodyear electronic mapping system (GEMS) are analyzed in conjunction with imagery generated by the satelliteborne Seasat/SAR. The GEMS operated with an incidence angle of 75 to 85 deg and a resolution of 12 m, whereas the Seasat/SAR operated with an incidence angle of 23 deg and a resolution of 25 m. It is found that otherwise unattainable data on land management activities, improved delineation of the drainage net, better definition of surface roughness in cleared areas, and swamp identification, became accessible when adjustments for the time lapse between the two missions were made and supporting ground data concerning the physical and vegetative characteristics of the terrain were acquired.

  15. Ground truth measurement for the analysis of airborne SAR data recorded over Oberpfaffenhofen, FRG, 1989

    NASA Technical Reports Server (NTRS)

    Bayer, T.; Wieneke, F.; Winter, R.

    1990-01-01

    As a preliminary investigation to the joint multiparameter SIR-C/X-SAR shuttle experiment of NASA/JPL (USA), DLR (FRG), and PSN (Italy) which is scheduled for the year 1992 an airborne SAR campaign was conducted over Oberpfaffenhofen, FRG, in August 1989. Primarily this campaign was planned to test and verify equipment and algorithms developed at the DLR to calibrate multifrequency polarimetric SAR data. Oberpfaffenhofen is designated as one of the super test sites for the SIR-C/X-SAR experiment which will be imaged under all circumstances except severe mission errors. A super test site drives radar parameters and look directions and the recorded SAR data will be calibrated. In addition ancillary data will be available for the site. During the airborne STAR campaign conducted in the week of August 14th 1989 various sensor types were used to record remote sensing data over the calibration test site and its vicinity: the polarimetric DC-8 JPL-SAR (P-, L-, C-band), the DLR airborne SAR (C-, X-band), color infrared aerial photography (DLR), and the truck-mounted scatterometer (C- and X-band) of the Institute for Navigation, University of Stuttgart (INS). Because of this variety of different sensor types used and out of the fact that sufficiently large forested and agriculturally used areas were planned to be covered by these sensors, the interest of several German research groups involved in investigations concerning SAR land applications arose. The following groups carried out different ground-truth measurements: University of Bonn, Institute for plant cultivation (plant morphology and moisture content); University of Braunschweig, Institute for Geography (soil moisture and surface roughness); University of Freiburg, Institute for Geography (dielectric soil properties, landuse); and University of Munich, Institute for Geography (landuse inventory, plant, surface, and soil parameters). This paper presents the joint ground truth activities of the Institute for Geography

  16. Airborne Oceanographic Lidar System

    NASA Technical Reports Server (NTRS)

    Bressel, C.; Itzkan, I.; Nunes, J. E.; Hoge, F.

    1977-01-01

    The Airborne Oceanographic Lidar (AOL), a spatially scanning range-gated device installed on board a NASA C-54 aircraft, is described. The AOL system is capable of measuring topographical relief or water depth (bathymetry) with a range resolution of plus or minus 0.3 m in the vertical dimension. The system may also be used to measure fluorescent spectral signatures from 3500 to 8000 A with a resolution of 100 A. Potential applications of the AOL, including sea state measurements, water transparency assessments, oil spill identification, effluent identification and crop cover assessment are also mentioned.

  17. System Turns SAR Images Into Maps

    NASA Technical Reports Server (NTRS)

    Curlander, J. C.; Kwok, Ronald; Pang, Shirley S. N.

    1988-01-01

    Postprocessing system for synthetic-aperture radar (SAR) transforms raw images from natural rotated and distorted SAR reference frame into geocoded images. Images automatically corrected to remove slant-range nonlinearities and Doppler skew. Produces multiple-frame mosaics for large-scale mapping. Does not require tedious manual registration of representative "tie" points in raw SAR imagery with known locations on Earth.

  18. Airborne Warning and Control System Block 40/45 Upgrade (AWACS Blk 40/45 Upgrade)

    DTIC Science & Technology

    2015-12-01

    Selected Acquisition Report (SAR) RCS: DD-A&T(Q&A)823-277 Airborne Warning and Control System Block 40/45 Upgrade (AWACS Blk 40/45 Upgrade) As of...PEO - Program Executive Officer PM - Program Manager POE - Program Office Estimate RDT&E - Research, Development, Test, and Evaluation SAR - Selected

  19. Airborne precursor missions in support of SIR-C/X-SAR

    NASA Technical Reports Server (NTRS)

    Evans, D.; Oettl, H.; Pampaloni, P.

    1991-01-01

    The NASA DC-8 and DLR E-SAR airborne imaging radars have been deployed over several sites in Europe and the U.S. in support of SIR-C/X-SAR (Shuttle Imaging Radar-C/X-Synthetic Aperture Radar) science team investigations. To date, data have been acquired in support of studies of alpine glaciers, forests, geology, oceanography, and calibration. An experimental campaign with airborne sensors will take place in Europe in June to July 1991 which will allow multitemporal surveys of several Europeans sites. Current plans are for calibration and ecology experiments to be undertaken in Germany, the Netherlands, Italy, France, and the United Kingdom. Coordinated multitemporal aircraft and ground campaigns are planned in support of hydrology experiments in Italy, the United Kingdom, and Austria. Data will also be acquired in support of oceanogrqhy in the Gulf of Genova, North Atlantic, Straits of Messina and the North Sea. Geology sites will include Campi Flegrei and Vesuvio, Italy.

  20. Airborne rescue system

    NASA Technical Reports Server (NTRS)

    Haslim, Leonard A. (Inventor)

    1991-01-01

    The airborne rescue system includes a boom with telescoping members for extending a line and collar to a rescue victim. The boom extends beyond the tip of the helicopter rotor so that the victim may avoid the rotor downwash. The rescue line is played out and reeled in by winch. The line is temporarily retained under the boom. When the boom is extended, the rescue line passes through clips. When the victim dons the collar and the tension in the line reaches a predetermined level, the clips open and release the line from the boom. Then the rescue line can form a straight line between the victim and the winch, and the victim can be lifted to the helicopter. A translator is utilized to push out or pull in the telescoping members. The translator comprises a tape and a rope. Inside the telescoping members the tape is curled around the rope and the tape has a tube-like configuration. The tape and rope are provided from supply spools.

  1. Use of airborne polarimetric SAR, optical and elevation data for mapping and monitoring of salt marsh vegetation habitats

    NASA Astrophysics Data System (ADS)

    van Beijma, Sybrand; Comber, Alexis; Lamb, Alistair

    2014-10-01

    Within the Copernicus programme there is much interest in the ability of remote sensing technology to deliver operational solutions to many areas of life including environmental management. This paper describes research focused on the application of Earth Observation for Integrated Coastal Zone Management. The main topic of this research is to explore to which extent salt marsh vegetation habitats can be identified from polarimetric SAR remotely sensed data. Multi-frequency, multi-polarimetric SAR images from airborne (S- and X-Band quad-polarimetric from the Astrium airborne SAR Demonstrator) is used to examine salt marsh habitat classification potential in the Llanrhidian salt marshes in South Wales, UK. This is achieved by (1) using both supervised and unsupervised classification routines, using several polarimetric SAR data layers as backscatter intensity, band ratios and polarimetric decomposition products, and by (2) statistical analysis by regression of these different SAR data layers and botanical parameters acquired from recent ecological fieldwork.

  2. Airborne Global Positioning System Antenna System

    DTIC Science & Technology

    2004-10-14

    GLOBAL POSITIONING SYSTEM ANTENNA SYSTEM DISTRIBUTION: SMC/ GP (3 cys); AFFSA...standard that airborne Global Positioning System ( GPS ) antenna system must meet to be identified with the applicable MSO marking. The similarity of...UNCLASSIFIED DOCUMENT NO. DATE NO. MSO-C144 14 Oct 04 Initial Release REV: REV: SHEET 1 OF 16 TITLE: AIRBORNE GLOBAL POSITIONING SYSTEM

  3. The relationship between aboveground biomass and radar backscatter as observed on airborne SAR imagery

    NASA Technical Reports Server (NTRS)

    Kasischke, Eric S.; Bourgeau-Chavez, Laura L.; Christensen, Norman L., Jr.; Dobson, M. Craig

    1991-01-01

    The initial results of an experiment to examine the dependence of radar image intensity on total above-ground biomass in a southern US pine forest ecosystem are presented. Two sets of data are discussed. First, we examine two L-band (VV-polarization) data sets which were collected 5 years apart. These data sets clearly illustrate the change in backscatter resulting from the growth of a young pine stand. Second, we examine the dependence between radar backscatter and biomass as a function of radar frequency using data from the JPL Airborne Synthetic Aperture Radar (AIRSAR) and ERIM/NADC P-3 SAR systems. These results show that there is a positive correlation between above-ground biomass and radar backscatter and at C-, L-, and P-bands, but very little correlation at C-band. The biomass level for which this positive correlation holds decreases as radar frequency increases. This positive correlation is stronger at HH and HV polarizations that VV polarization at L- and P-bands, but strongest at VV polarization for C-band.

  4. Airborne wireless communication systems, airborne communication methods, and communication methods

    DOEpatents

    Deaton, Juan D [Menan, ID; Schmitt, Michael J [Idaho Falls, ID; Jones, Warren F [Idaho Falls, ID

    2011-12-13

    An airborne wireless communication system includes circuitry configured to access information describing a configuration of a terrestrial wireless communication base station that has become disabled. The terrestrial base station is configured to implement wireless communication between wireless devices located within a geographical area and a network when the terrestrial base station is not disabled. The circuitry is further configured, based on the information, to configure the airborne station to have the configuration of the terrestrial base station. An airborne communication method includes answering a 911 call from a terrestrial cellular wireless phone using an airborne wireless communication system.

  5. Airborne & SAR Synergy Reveals the 3D Structure of Air Bubble Entrainment in Internal Waves and Frontal Zones

    NASA Astrophysics Data System (ADS)

    da Silva, J. C. B.; Magalhaes, J. M.; Batista, M.; Gostiaux, L.; Gerkema, T.; New, A. L.

    2013-03-01

    spectral range 8-12 μm. With a nominal ground resolution of approximately 1.5 meters (at an altitude of 500 meters) it is capable to detect fine structure associated to turbulence. The LiDAR system that has been used is the Leica ALS50-II (1064nm) with a hit rate greater than 1 hit per square meter and a vertical resolution of approximately 15 cm. Both systems were available simultaneously, together with the hyperspectral system and the RCD105 39Mpx digital camera, integrated with the LiDAR navigation system. We analyse the airborne data together with a comprehensive dataset of satellite Synthetic Aperture Radar (SAR) that includes ENVISAT and TerraSAR-X images. In addition, in situ observations in the near-shore zone were obtained in a previous experiment (Project SPOTIWAVE-II POCI/MAR/57836/2004 funded by the Portuguese FCT) during the summer period in 2006. These included thermistor chain measurements along the water column that captured the vertical structure of shoaling internal (tidal) waves and ISWs close to the breaking point. The SAR and airborne images were obtained in light wind conditions, in the near-shore zone, and in the presence of ISWs. The LiDAR images revealed sub-surface structures (some 1-2 m below the sea surface) that were co-located with surface films. These film slicks were induced by the convergent fields of internal waves and upwelling fronts. Some of the sub-surface features were located over the front slopes of the internal waves, which coincides with the internal wave slick band visible in the aerial photos and hyperspectral systems. Our flight measurements revealed thermal features similar to “boils” of cold water within the wake of (admittedly breaking) internal waves. These features are consistent with the previous in situ measurements of breaking ISWs. In this paper we will show coincident multi-sensor airborne and satellite SAR observations that reveal the 3D structure of air bubble entrainment in the internal wave field and frontal

  6. SAR processing using SHARC signal processing systems

    NASA Astrophysics Data System (ADS)

    Huxtable, Barton D.; Jackson, Christopher R.; Skaron, Steve A.

    1998-09-01

    Synthetic aperture radar (SAR) is uniquely suited to help solve the Search and Rescue problem since it can be utilized either day or night and through both dense fog or thick cloud cover. Other papers in this session, and in this session in 1997, describe the various SAR image processing algorithms that are being developed and evaluated within the Search and Rescue Program. All of these approaches to using SAR data require substantial amounts of digital signal processing: for the SAR image formation, and possibly for the subsequent image processing. In recognition of the demanding processing that will be required for an operational Search and Rescue Data Processing System (SARDPS), NASA/Goddard Space Flight Center and NASA/Stennis Space Center are conducting a technology demonstration utilizing SHARC multi-chip modules from Boeing to perform SAR image formation processing.

  7. Forest Stand Volume Estimation Using Airborne LIDAR And Polarimetric SAR Over Hilly Region

    NASA Astrophysics Data System (ADS)

    Fan, Fengyun; Chen, Erxue; Li, Zengyuan; Liu, Qingwang; Li, Shiming; Ling, Feilong

    2010-10-01

    In order to investigate the potential capability of mapping forest stand volume using the multi-sources data, ALOS PALSAR, airborne LiDAR and high resolution CCD image in forest stand level, one test site located in the warm temperate hilly forest region of Shandong Province in China was established. Airborne LiDAR and CCD campaign was carried out in the end of May, 2005. One scene of ALOS PALSAR quad-polarization image was acquired in May 19th,2007. Ground forest plot data for Black Locust and Chinese Pine dominated forest stands were collected through field work from May to June of 2008. The correlations of forest stand volume to PALSAR backscattering coefficient of HH, HV, VH,VV, their ratio and some H-Alpha polarimetric decomposition parameters were analyzed in stand level through regression analysis. Mean forest stand volume of each polygons (forest stand) was finally estimated based on the regression model established using ground measured forest volume data and the corresponding parameters (polygon mean) derived from LiDAR CHM and polarimetric SAR data. Results show that it is feasible to combine low density LiDAR data, L-band SAR data and forest polygon data from high resolution CCD image for stand level forest volume estimation in hilly regions, the RMSE is 20.064m3/ha for Black Locust and 24.730m3/ha for Chinese Pine .

  8. Forest Stand Volume Estimation Using Airborne LIDAR And Polarimetric SAR Over Hilly Region

    NASA Astrophysics Data System (ADS)

    Fan, Fengyun; Chen, Erxue; Li, Zengyuan; Liu, Qingwang; Li, Shiming; Ling, Feilong; Pottier, Eric; Cloude, Shane

    2010-10-01

    In order to investigate the potential capability of mapping forest stand volume using the multi-sources data, ALOS PALSAR, airborne LiDAR and high resolution CCD image in forest stand level, one test site located in the warm temperate hilly forest region of Shandong Province in China was established. Airborne LiDAR and CCD campaign was carried out in the end of May, 2005. One scene of ALOS PALSAR quad-polarization image was acquired in May 19th,2007. Ground forest plot data for Black Locust and Chinese Pine dominated forest stands were collected through field work from May to June of 2008. The correlations of forest stand volume to PALSAR backscattering coefficient of HH, HV,VH,VV, their ratio and some H-Alpha polarimetric decomposition parameters were analyzed in stand level through regression analysis. Mean forest stand volume of each polygons (forest stand) was finally estimated based on the regression model established using ground measured forest volume data and the corresponding parameters (polygon mean) derived from LiDAR CHM and polarimetric SAR data. Results show that it is feasible to combine low density LiDAR data, L-band SAR data and forest polygon data from high resolution CCD image for stand level forest volume estimation in hilly regions, the RMSE is 20.064m3/ha for Black Locust and 24.730m3/ha for Chinese Pine .

  9. Geophex Airborne Unmanned Survey System

    SciTech Connect

    Won, I.J.; Keiswetter, D.

    1995-10-01

    The purpose of this effort is to design, construct, and evaluate a portable, remotely-piloted, airborne, geophysical survey system. This non-intrusive system will provide {open_quotes}stand-off{close_quotes} capability to conduct surveys and detect buried objects, structures, and conditions of interest at hazardous locations. This system permits rapid geophysical characterization of hazardous environmental sites. During a survey, the operators remain remote from, but within visual distance of, the site. The sensor system never contacts the Earth, but can be positioned near the ground so that weak geophysical anomalies can be detected.

  10. Geophex airborne unmanned survey system

    SciTech Connect

    Won, I.J.; Taylor, D.W.A.

    1995-03-01

    The purpose of this effort is to design, construct, and evaluate a portable, remotely-piloted, airborne, geophysical survey system. This nonintrusive system will provide {open_quotes}stand-off{close_quotes} capability to conduct surveys and detect buried objects, structures, and conditions of interest at hazardous locations. This system permits two operators to rapidly conduct geophysical characterization of hazardous environmental sites. During a survey, the operators remain remote from, but within visual distance, of, the site. The sensor system never contacts the Earth, but can be positioned near the ground so that weak anomalies can be detected.

  11. Seasonal Thickness Changes Revealed by Airborne Radar Interferometry, Pi-SAR2, at Two Glaciers Near Mt. Tsurugi, Japan

    NASA Astrophysics Data System (ADS)

    Furuya, M.; Fukui, K.; Kojima, S.; Matsuoka, T.

    2015-12-01

    Based on ice radar and high-preicision GPS measurements, Fukui and Iida (2012) have reported the presence of "glaciers" near Mt. Tsurugi, central Japan, which had been previously regarded as perenial snowy gorges. While their discovery was brought out by the modern geodetic techniques, there used to be a wrong idea that the equilibrium line altitude in central Japanese Alps is about 4000 meter, causing the actual glaciers to be overlooked; the elevation of Mt Tsurugi is 2999 meter. The presence of glaciers in central Japan is due to the very high seasonal accmulation; the snow fall in the mountainous regions can reach several tens of meters or more. There are, however, few snow-depth measurement data due to the logistic problems. The equilibrium line altitude also remains uncertain. We have performed airborne synthetic aperture radar (SAR) measurements near the two glaciers in August, October 2013, August 2014, and March 2015. The Pi-SAR2 system used in this study consists of X-band SAR antennas, and allows us to perform single-pass interferometry and full polarimetry with the maximum spatial resolution of 0.3 m. Taking advantage of the single-pass interferometry, we have generated digital elevation models (DEM) at each measurement epoch to derive the temporal changes in the thickness by differecing the DEMs of multiple epochs. Snow melt season starts in May at the analyzed area, and the first snow fall usually occurs in late October. As such, the minimum thickness is expected in October, when the glacier ice appears on the surface. Preliminary analyses indicate that the differences between August and October 2013 reaches ~10 to 20 meters with errors of 5-10 meters.

  12. High-Accuracy Elevation Data at Large Scales from Airborne Single-Pass SAR Interferometry

    NASA Astrophysics Data System (ADS)

    Schumann, Guy; Moller, Delwyn; Mentgen, Felix

    2015-12-01

    Digital elevation models (DEMs) are essential data sets for disaster risk management and humanitarian relief services as well as many environmental process models. At present, on the hand, globally available DEMs only meet the basic requirements and for many services and modeling studies are not of high enough spatial resolution and lack accuracy in the vertical. On the other hand, LiDAR-DEMs are of very high spatial resolution and great vertical accuracy but acquisition operations can be very costly for spatial scales larger than a couple of hundred square km and also have severe limitations in wetland areas and under cloudy and rainy conditions. The ideal situation would thus be to have a DEM technology that allows larger spatial coverage than LiDAR but without compromising resolution and vertical accuracy and still performing under some adverse weather conditions and at a reasonable cost. In this paper, we present a novel single pass In-SAR technology for airborne vehicles that is cost-effective and can generate DEMs with a vertical error of around 0.3 m for an average spatial resolution of 3 m. To demonstrate this capability, we compare a sample single-pass In-SAR Ka-band DEM of the California Central Valley from the NASA/JPL airborne GLISTIN-A to a high-resolution LiDAR DEM. We also perform a simple sensitivity analysis to floodplain inundation. Based on the findings of our analysis, we argue that this type of technology can and should be used to replace large regions of globally available lower resolution DEMs, particularly in coastal, delta and floodplain areas where a high number of assets, habitats and lives are at risk from natural disasters. We conclude with a discussion on requirements, advantages and caveats in terms of instrument and data processing.

  13. Lineaments from airborne SAR images and the 1988 Saguenay earthquake, Quebec, Canada

    SciTech Connect

    Roy, D.W.; Schmitt, L.; Woussen, G.; Duberger, R. )

    1993-08-01

    Airborne SAR images provided essential clues to the tectonic setting of (1) the MbLg 6.5 Saguenay earthquake of 25 November 1988, (2) the Charlevoix-Kamouraska seismic source zone, and (3) some of the low *eve* seismic activity in the Eastern seismic background zone of Canada. The event occurred in the southeastern part of the Canadian Shield in an area where the boundary between the Saguenay graben and the Jacques Cartier horst is not well defined. These two tectonic blocks are both associated with the Iapetan St-Lawrence rift. These blocks exhibit several important structural breaks and distinct domains defined by the lineament orientations, densities, and habits. Outcrop observations confirm that several lineament sets correspond to Precambrian ductile shear zones reactivated as brittle faults during the Phanerozoic. In addition, the northeast and southwest limits of recent seismic activity in the Charlevoix-Kamouraska zone correspond to major elements of the fracture pattern identified on the SAR images. These fractures appear to be related to the interaction of the Charlevoix astrobleme with the tectonic features of the area. 20 refs.

  14. Geophex Airborne Unmanned Survey System

    SciTech Connect

    Won, I.L.; Keiswetter, D.

    1995-12-31

    Ground-based surveys place personnel at risk due to the proximity of buried unexploded ordnance (UXO) items or by exposure to radioactive materials and hazardous chemicals. The purpose of this effort is to design, construct, and evaluate a portable, remotely-piloted, airborne, geophysical survey system. This non-intrusive system will provide stand-off capability to conduct surveys and detect buried objects, structures, and conditions of interest at hazardous locations. During a survey, the operators remain remote from, but within visual distance of, the site. The sensor system never contacts the Earth, but can be positioned near the ground so that weak geophysical anomalies can be detected. The Geophex Airborne Unmanned Survey System (GAUSS) is designed to detect and locate small-scale anomalies at hazardous sites using magnetic and electromagnetic survey techniques. The system consists of a remotely-piloted, radio-controlled, model helicopter (RCH) with flight computer, light-weight geophysical sensors, an electronic positioning system, a data telemetry system, and a computer base-station. The report describes GAUSS and its test results.

  15. Flood disaster monitoring in Thailand by using a airborne L-band SAR: Polarimetric and interferometry Synthetic Aperture Radar with L-band(Pi-SAR-L)

    NASA Astrophysics Data System (ADS)

    Kawano, N.; Sobue, S.; Shimada, M.; Ohyoshi, K.

    2012-04-01

    It was heavy rainfall around the northern region of Thailand from July to September 2011, which caused flood disaster to quite wide region of Thailand, it finally reached to the Bangkok central in the end of October 2011. Japan Aerospace Exploration Agency (JAXA) conducted an emergency observation by using a airborne L-band SAR: Polarimetric and interferometry Synthetic Aperture Radar with L-band(Pi-SAR-L) from 5th to 27th November to monitor flood area. Pi-SAR-L has a center frequency of 1271.5 MHz, a band width of 50 MHz, a slant range resolution of 3 m, and an acquisition swath of 15 km on the ground. Pi-SAR-L is boarded on an aircraft of the Gulfstream-II operated by the Diamond Air Service(DAS), Japan, and the Gulfstream-II was ferried to the Chieng-Mai airport in the North Thailand, from Japan. In our presentation, we will show flood area around Bangkok and its variations detected by Pi-SAR-L

  16. GeoSAR: A Radar Terrain Mapping System for the New Millennium

    NASA Technical Reports Server (NTRS)

    Thompson, Thomas; vanZyl, Jakob; Hensley, Scott; Reis, James; Munjy, Riadh; Burton, John; Yoha, Robert

    2000-01-01

    GeoSAR Geographic Synthetic Aperture Radar) is a new 3 year effort to build a unique, dual-frequency, airborne Interferometric SAR for mapping of terrain. This is being pursued via a Consortium of the Jet Propulsion Laboratory (JPL), Calgis, Inc., and the California Department of Conservation. The airborne portion of this system will operate on a Calgis Gulfstream-II aircraft outfitted with P- and X-band Interferometric SARs. The ground portions of this system will be a suite of Flight Planning Software, an IFSAR Processor and a Radar-GIS Workstation. The airborne P-band and X-band radars will be constructed by JPL with the goal of obtaining foliage penetration at the longer P-band wavelengths. The P-band and X-band radar will operate at frequencies of 350 Mhz and 9.71 Ghz with bandwidths of either 80 or 160 Mhz. The airborne radars will be complemented with airborne laser system for measuring antenna positions. Aircraft flight lines and radar operating instructions will be computed with the Flight Planning Software The ground processing will be a two-step step process. First, the raw radar data will be processed into radar images and interferometer derived Digital Elevation Models (DEMs). Second, these radar images and DEMs will be processed with a Radar GIS Workstation which performs processes such as Projection Transformations, Registration, Geometric Adjustment, Mosaicking, Merging and Database Management. JPL will construct the IFSAR Processor and Calgis, Inc. will construct the Radar GIS Workstation. The GeoSAR Project was underway in November 1996 with a goal of having the radars and laser systems fully integrated onto the Calgis Gulfstream-II aircraft in early 1999. Then, Engineering Checkout and Calibration-Characterization Flights will be conducted through November 1999. The system will be completed at the end of 1999 and ready for routine operations in the year 2000.

  17. Airborne Relay-Based Regional Positioning System

    PubMed Central

    Lee, Kyuman; Noh, Hongjun; Lim, Jaesung

    2015-01-01

    Ground-based pseudolite systems have some limitations, such as low vertical accuracy, multipath effects and near-far problems. These problems are not significant in airborne-based pseudolite systems. However, the monitoring of pseudolite positions is required because of the mobility of the platforms on which the pseudolites are mounted, and this causes performance degradation. To address these pseudolite system limitations, we propose an airborne relay-based regional positioning system that consists of a master station, reference stations, airborne relays and a user. In the proposed system, navigation signals are generated from the reference stations located on the ground and are relayed via the airborne relays. Unlike in conventional airborne-based systems, the user in the proposed system sequentially estimates both the locations of airborne relays and his/her own position. Therefore, a delay due to monitoring does not occur, and the accuracy is not affected by the movement of airborne relays. We conducted several simulations to evaluate the performance of the proposed system. Based on the simulation results, we demonstrated that the proposed system guarantees a higher accuracy than airborne-based pseudolite systems, and it is feasible despite the existence of clock offsets among reference stations. PMID:26029953

  18. Ambiguity noise analysis of a SAR system

    NASA Astrophysics Data System (ADS)

    Tian, Haishan; Chang, Wenge; Li, Xiangyang

    2015-12-01

    The presence of range and azimuth (or Doppler) ambiguities in synthetic aperture radars (SARs) is well known. The ambiguity noise is related to the antenna pattern and the value of pulse repetition frequency (PRF). Because a new frequency modulated continuous wave (FMCW) SAR has the characters of low cost and small size, and the capacity of real-time signal processing, the antenna will likely vibrate or deform due to a lack of the stabilized platform. And the value of PRF cannot be much high because of the high computation burden for the real-time processing. The aim of this study is to access and improve the performance of a new FMCW SAR system based on the ambiguity noise. First, the quantitative analysis of the system's ambiguity noise level is performed; an antenna with low sidelobes is designed. The conclusion is that the range ambiguity noise is small; the azimuth ambiguity noise is somewhat increased, however, it is sufficiently small to have marginal influence on the image quality. Finally, the ambiguity noise level is measured using the imaging data from a Ku-band FMCW SAR. The results of this study show that the measured noise level coincides with the theoretical noise level.

  19. Wind-wave-induced velocity in ATI SAR ocean surface currents: First experimental evidence from an airborne campaign

    NASA Astrophysics Data System (ADS)

    Martin, Adrien C. H.; Gommenginger, Christine; Marquez, Jose; Doody, Sam; Navarro, Victor; Buck, Christopher

    2016-03-01

    Conventional and along-track interferometric (ATI) Synthetic Aperture Radar (SAR) senses the motion of the ocean surface by measuring the Doppler shift of reflected signals. Measurements are affected by a Wind-wave-induced Artifact Surface Velocity (WASV) which was modeled theoretically in past studies and has been estimated empirically only once before with Envisat ASAR by Mouche et al. (2012). An airborne campaign in the tidally dominated Irish Sea served to evaluate this effect and the current retrieval capabilities of a dual-beam SAR interferometer known as Wavemill. A comprehensive collection of Wavemill airborne data acquired in a star pattern over a well-instrumented validation site made it possible for the first time to estimate the magnitude of the WASV, and its dependence on azimuth and incidence angle from data alone. In light wind (5.5 m/s) and moderate current (0.7 m/s) conditions, the wind-wave-induced contribution to the measured ocean surface motion reaches up to 1.6 m/s upwind, with a well-defined second-order harmonic dependence on direction to the wind. The magnitude of the WASV is found to be larger at lower incidence angles. The airborne WASV results show excellent consistency with the empirical WASV estimated from Envisat ASAR. These results confirm that SAR and ATI surface velocity estimates are strongly affected by WASV and that the WASV can be well characterized with knowledge of the wind knowledge and of the geometry. These airborne results provide the first independent validation of Mouche et al. (2012) and confirm that the empirical model they propose provides the means to correct airborne and spaceborne SAR and ATI SAR data for WASV to obtain accurate ocean surface current measurements. After removing the WASV, the airborne Wavemill-retrieved currents show very good agreement against ADCP measurements with a root-mean-square error (RMSE) typically around 0.1 m/s in velocity and 10° in direction.

  20. Fault and anthropogenic processes in central California constrained by satellite and airborne InSAR and in-situ observations

    NASA Astrophysics Data System (ADS)

    Liu, Zhen; Lundgren, Paul

    2016-07-01

    The San Andreas Fault (SAF) system is the primary plate boundary in California, with the central SAF (CSAF) lying adjacent to the San Joaquin Valley (SJV), a vast structural trough that accounts for about one-sixth of the United Sates' irrigated land and one-fifth of its extracted groundwater. The CSAF displays a range of fault slip behavior with creeping in its central segment that decreases towards its northwest and southeast ends, where the fault transitions to being fully locked. At least six Mw ~6.0 events since 1857 have occurred near the Parkfield transition, most recently in 2004. Large earthquakes also occurred on secondary faults parallel to the SAF, the result of distributed deformation across the plate boundary zone. Recent studies have revealed the complex interaction between anthropogenic related groundwater depletion and the seismic activity on adjacent faults through stress interaction. Despite recent progress, many questions regarding fault and anthropogenic processes in the region still remain. For example, how is the relative plate motion accommodated between the CSAF and off-fault deformation? What is the distribution of fault creep and slip deficit at shallow depths? What are the spatiotemporal variations of fault slip? What are the spatiotemporal characteristics of anthropogenic and lithospheric processes and how do they interact with each other? To address these, we combine satellite InSAR and NASA airborne UAVSAR data to image on and off-fault deformation. The UAVSAR data cover fault perpendicular swaths imaged from opposing look directions and fault parallel swaths since 2009. The much finer spatial resolution and optimized viewing geometry provide important constraints on near fault deformation and fault slip at very shallow depth. We performed a synoptic InSAR time series analysis using ERS-1/2, Envisat, ALOS and UAVSAR interferograms. The combined C-band ERS-1/2 and Envisat data provide a long time interval of SAR data over the region

  1. Airborne microwave radiometric imaging system

    NASA Astrophysics Data System (ADS)

    Guo, Wei; Li, Futang; Zhang, Zuyin

    1999-09-01

    A dual channel Airborne Microwave Radiometric Imaging system (AMRI) was designed and constructed for regional environment mapping. The system operates at 35GHz, which collects radiation at horizontal and vertical polarized channels. It runs at mechanical conical scanning with 45 degrees incidence angle. Two Cassegrain antennas with 1.5 degrees beamwidth scan the scene alternately and two pseudo- color images of two channels are displayed on the screen of PC in real time. Simultaneously, all parameters of flight and radiometric data are sorted in hard disk for post- processing. The sensitivity of the radiometer (Delta) T equals 0.16K. A new displaying method, unequal size element arc displaying method, is used in image displaying. Several experiments on mobile tower were carried out and the images demonstrate that the AMRI is available to work steadily and accurately.

  2. Airborne microwave radiometric imaging system

    NASA Astrophysics Data System (ADS)

    Guo, Wei; Zhang, Zuyin; Chen, Zhengwen

    1998-08-01

    A dual channel Airborne Microwave Radiometric Imaging system (AMRI) was designed and constructed for regional environment mapping. The system operates at 35GHz, which collects radiation at horizontal and vertical polarized. It runs at mechanical conical scanning with 45 degrees incidence angle. Two Cassegrain antennas with 1.5 degrees 3 dB beamwidth scan the scene alternately and two pseudo-color images of two channels are displayed on the screen of PC in real time. Simultaneously all parameters of flight and radiometric data are stored in hard disk for postprocessing. The sensitivity of the radiometers of flight and radiometric data are stored in hard disk for postprocessing. The sensitivity of the radiometers (Delta) T equals 0.16K. A new display method, unequal size element arc displaying method, is used in image displaying. Several experiments on mobile tower were carried out and the images demonstrate the AMRI is available to work steadily and accurately.

  3. PRF Ambiguity Detrmination for Radarsat ScanSAR System

    NASA Technical Reports Server (NTRS)

    Jin, Michael Y.

    1998-01-01

    PRF ambiguity is a potential problem for a spaceborne SAR operated at high frequencies. For a strip mode SAR, there were several approaches to solve this problem. This paper, however, addresses PRF ambiguity determination algorithms suitable for a burst mode SAR system such as the Radarsat ScanSAR. The candidate algorithms include the wavelength diversity algorithm, range look cross correlation algorithm, and multi-PRF algorithm.

  4. International collaboration in SAR ground data systems

    NASA Technical Reports Server (NTRS)

    Curlander, John C.

    1993-01-01

    A set of considerations that are pertinent to future international cooperation in the area of synthetic aperture radar (SAR) ground data systems are presented. The considerations are as follows: (1) success of future spaceborne SAR missions will require multi-agency and/or multi-national collaboration; (2) ground processing is typically performed by each agency for their user base; (3) international standards are required to achieve a uniform data product independent of the processing center; (4) to reduce the aggregate cost of the ground data systems, collaboration is required in design and development; (5) effective utilization of the data by an international user community; (6) commercialization of data products; and (7) security of data systems.

  5. Airborne SAR determination of relative ages of Walker Valley moraines, eastern Sierra Nevada

    NASA Technical Reports Server (NTRS)

    Fox, A.; Isacks, B.; Bloom, A.; Fielding, E.; Mcmurry, D.

    1991-01-01

    A regional study of the distribution and elevations of Pleistocene moraines in the Andes requires a method of determining relative age from space. One of our primary objectives is to establish the relative chronology of major climatic events responsible for glaciation in the Andes and other regions that are difficult to access on the ground and where suitable material for absolute age determination is lacking. The sensitivity of radar to surface roughness makes it possible to develop a remotely-based relative dating technique for landforms for which surface age and roughness can be correlated. We are developing such a technique with Airborne Synthetic Aperture Radar (AIRSAR) imagery of the eastern Sierra Nevada where independent evidence is available for the ages and physical characteristics of moraines. The Sierra Nevada moraines are similar in form and environmental setting to Andean moraines that we have targeted for study during the pending Shuttle Imaging Radar-C (SIR-C) mission. SAR imagery is used to differentiate the ages of five moraine sequences of Walker Valley in the eastern Sierra Nevada. Other aspects of this investigation are briefly discussed.

  6. Alaska SAR Facility mass storage, current system

    NASA Technical Reports Server (NTRS)

    Cuddy, David; Chu, Eugene; Bicknell, Tom

    1993-01-01

    This paper examines the mass storage systems that are currently in place at the Alaska SAR Facility (SAF). The architecture of the facility will be presented including specifications of the mass storage media that are currently used and the performances that we have realized from the various media. The distribution formats and media are also discussed. Because the facility is expected to service future sensors, the new requirements and possible solutions to these requirements are also discussed.

  7. Downscaling of Airborne Wind Energy Systems

    NASA Astrophysics Data System (ADS)

    Fechner, Uwe; Schmehl, Roland

    2016-09-01

    Airborne wind energy systems provide a novel solution to harvest wind energy from altitudes that cannot be reached by wind turbines with a similar nominal generator power. The use of a lightweight but strong tether in place of an expensive tower provides an additional cost advantage, next to the higher capacity factor and much lower total mass. This paper investigates the scaling effects of airborne wind energy systems. The energy yield of airborne wind energy systems, that work in pumping mode of operation is at least ten times higher than the energy yield of conventional solar systems. For airborne wind energy systems the yield is defined per square meter wing area. In this paper the dependency of the energy yield on the nominal generator power for systems in the range of 1 kW to 1 MW is investigated. For the onshore location Cabauw, The Netherlands, it is shown, that a generator of just 1.4 kW nominal power and a total system mass of less than 30 kg has the theoretical potential to harvest energy at only twice the price per kWh of large scale airborne wind energy systems. This would make airborne wind energy systems a very attractive choice for small scale remote and mobile applications as soon as the remaining challenges for commercialization are solved.

  8. Quantification of L-band InSAR decorrelation in volcanic terrains using airborne LiDAR data

    NASA Astrophysics Data System (ADS)

    Sedze, M.; Heggy, E.; Jacquemoud, S.; Bretar, F.

    2011-12-01

    Repeat-pass InSAR LOS measurements of the Piton de La Fournaise (La Reunion Island, France) suffer from substantial phase decorrelation due to the occurrence of vegetation and ash deposits on the caldera and slopes of the edifice. To correct this deficiency, we combine normalized airborne LiDAR (Light Detection and Ranging) intensity data with spaceborne InSAR coherence images from ALOS PALSAR L-band acquired over the volcano in 2008 and 2009, following the 2007 major eruption. The fusion of the two data sets improves the calculation of coherence and the textural classification of different volcanic surfaces. For future missions considering both InSAR and/or LiDAR such as DESDynI (Deformation, Ecosystem Structure and Dynamics of Ice), such data fusion studies can provide a better analysis of the spatiotemporal variations in InSAR coherence in order to enhance the monitoring of pre-eruptive ground displacements. The airborne surveys conducted in 2008 and 2009, cover different types of vegetation and terrain roughness on the central and western parts of the volcano. The topographic data are first processed to generate a high-resolution digital terrain model (DTM) of the volcanic edifice with elevation accuracy better than 1 m. For our purposes, the phase variations caused by the surface relief can be eliminated using the LiDAR-derived DTM. Then normalized LiDAR intensities are correlated to the L-band polarimetric coherence for different zones of the volcano to assess the LiDAR-InSAR statistical behavior of different lava flows, pyroclastics, and vegetated surfaces. Results suggest that each volcanic terrain type is characterized by a unique LiDAR-InSAR histogram pattern. We identified four LiDAR-InSAR distinguished relations: (1) pahoehoe lava flow surfaces show an agglomerate histogram pattern which may be explained by low surface scattering and low wave penetration into the geological medium; (2) eroded a'a lava surfaces is characterized by high standard deviation

  9. Combined Use of Airborne Lidar and DBInSAR Data to Estimate LAI in Temperate Mixed Forests

    NASA Technical Reports Server (NTRS)

    Peduzzi, Alicia; Wynne, Randolph Hamilton; Thomas, Valerie A.; Nelson, Ross F.; Reis, James J.; Sanford, Mark

    2012-01-01

    The objective of this study was to determine whether leaf area index (LAI) in temperate mixed forests is best estimated using multiple-return airborne laser scanning (lidar) data or dual-band, single-pass interferometric synthetic aperture radar data (from GeoSAR) alone, or both in combination. In situ measurements of LAI were made using the LiCor LAI-2000 Plant Canopy Analyzer on 61 plots (21 hardwood, 36 pine, 4 mixed pine hardwood; stand age ranging from 12-164 years; mean height ranging from 0.4 to 41.2 m) in the Appomattox-Buckingham State Forest, Virginia, USA. Lidar distributional metrics were calculated for all returns and for ten one meter deep crown density slices (a new metric), five above and five below the mode of the vegetation returns for each plot. GeoSAR metrics were calculated from the X-band backscatter coefficients (four looks) as well as both X- and P-band interferometric heights and magnitudes for each plot. Lidar metrics alone explained 69% of the variability in LAI, while GeoSAR metrics alone explained 52%. However, combining the lidar and GeoSAR metrics increased the R2 to 0.77 with a CV-RMSE of 0.42. This study indicates the clear potential for X-band backscatter and interferometric height (both now available from spaceborne sensors), when combined with small-footprint lidar data, to improve LAI estimation in temperate mixed forests.

  10. The Ecosystems SAR (EcoSAR) an Airborne P-band Polarimetric InSAR for the Measurement of Vegetation Structure, Biomass and Permafrost

    NASA Technical Reports Server (NTRS)

    Rincon, Rafael F.; Fatoyinbo, Temilola; Ranson, K. Jon; Osmanoglu, Batuhan; Sun, Guoqing; Deshpande, Manohar D.; Perrine, Martin L.; Du Toit, Cornelis F.; Bonds, Quenton; Beck, Jaclyn; Lu, Daniel

    2014-01-01

    EcoSAR is a new synthetic aperture radar (SAR) instrument being developed at the NASA/ Goddard Space Flight Center (GSFC) for the polarimetric and interferometric measurements of ecosystem structure and biomass. The instrument uses a phased-array beamforming architecture and supports full polarimetric measurements and single pass interferometry. This Instrument development is part of NASA's Earth Science Technology Office Instrument Incubator Program (ESTO IIP).

  11. Polarimetric sensor systems for airborne ISR

    NASA Astrophysics Data System (ADS)

    Chenault, David; Foster, Joseph; Pezzaniti, Joseph; Harchanko, John; Aycock, Todd; Clark, Alex

    2014-06-01

    Over the last decade, polarimetric imaging technologies have undergone significant advancements that have led to the development of small, low-power polarimetric cameras capable of meeting current airborne ISR mission requirements. In this paper, we describe the design and development of a compact, real-time, infrared imaging polarimeter, provide preliminary results demonstrating the enhanced contrast possible with such a system, and discuss ways in which this technology can be integrated with existing manned and unmanned airborne platforms.

  12. A Novel Azimuth Super-Resolution Method by Synthesizing Azimuth Bandwidth of Multiple Tracks of Airborne Stripmap SAR Data.

    PubMed

    Wang, Yan; Li, Jingwen; Sun, Bing; Yang, Jian

    2016-06-13

    Azimuth resolution of airborne stripmap synthetic aperture radar (SAR) is restricted by the azimuth antenna size. Conventionally, a higher azimuth resolution should be achieved by employing alternate modes that steer the beam in azimuth to enlarge the synthetic antenna aperture. However, if a data set of a certain region, consisting of multiple tracks of airborne stripmap SAR data, is available, the azimuth resolution of specific small region of interest (ROI) can be conveniently improved by a novel azimuth super-resolution method as introduced by this paper. The proposed azimuth super-resolution method synthesize the azimuth bandwidth of the data selected from multiple discontinuous tracks and contributes to a magnifier-like function with which the ROI can be further zoomed in with a higher azimuth resolution than that of the original stripmap images. Detailed derivation of the azimuth super-resolution method, including the steps of two-dimensional dechirping, residual video phase (RVP) removal, data stitching and data correction, is provided. The restrictions of the proposed method are also discussed. Lastly, the presented approach is evaluated via both the single- and multi-target computer simulations.

  13. A Novel Azimuth Super-Resolution Method by Synthesizing Azimuth Bandwidth of Multiple Tracks of Airborne Stripmap SAR Data

    PubMed Central

    Wang, Yan; Li, Jingwen; Sun, Bing; Yang, Jian

    2016-01-01

    Azimuth resolution of airborne stripmap synthetic aperture radar (SAR) is restricted by the azimuth antenna size. Conventionally, a higher azimuth resolution should be achieved by employing alternate modes that steer the beam in azimuth to enlarge the synthetic antenna aperture. However, if a data set of a certain region, consisting of multiple tracks of airborne stripmap SAR data, is available, the azimuth resolution of specific small region of interest (ROI) can be conveniently improved by a novel azimuth super-resolution method as introduced by this paper. The proposed azimuth super-resolution method synthesize the azimuth bandwidth of the data selected from multiple discontinuous tracks and contributes to a magnifier-like function with which the ROI can be further zoomed in with a higher azimuth resolution than that of the original stripmap images. Detailed derivation of the azimuth super-resolution method, including the steps of two-dimensional dechirping, residual video phase (RVP) removal, data stitching and data correction, is provided. The restrictions of the proposed method are also discussed. Lastly, the presented approach is evaluated via both the single- and multi-target computer simulations. PMID:27304959

  14. Airborne space laser communication system and experiments

    NASA Astrophysics Data System (ADS)

    Li, Xiao-Ming; Zhang, Li-zhong; Meng, Li-Xin

    2015-11-01

    Airborne space laser communication is characterized by its high speed, anti-electromagnetic interference, security, easy to assign. It has broad application in the areas of integrated space-ground communication networking, military communication, anti-electromagnetic communication. This paper introduce the component and APT system of the airborne laser communication system design by Changchun university of science and technology base on characteristic of airborne laser communication and Y12 plan, especially introduce the high communication speed and long distance communication experiment of the system that among two Y12 plans. In the experiment got the aim that the max communication distance 144Km, error 10-6 2.5Gbps - 10-7 1.5Gbps capture probability 97%, average capture time 20s. The experiment proving the adaptability of the APT and the high speed long distance communication.

  15. Airborne Turbulence Detection System Certification Tool Set

    NASA Technical Reports Server (NTRS)

    Hamilton, David W.; Proctor, Fred H.

    2006-01-01

    A methodology and a corresponding set of simulation tools for testing and evaluating turbulence detection sensors has been presented. The tool set is available to industry and the FAA for certification of radar based airborne turbulence detection systems. The tool set consists of simulated data sets representing convectively induced turbulence, an airborne radar simulation system, hazard tables to convert the radar observable to an aircraft load, documentation, a hazard metric "truth" algorithm, and criteria for scoring the predictions. Analysis indicates that flight test data supports spatial buffers for scoring detections. Also, flight data and demonstrations with the tool set suggest the need for a magnitude buffer.

  16. Airborne laser sensors and integrated systems

    NASA Astrophysics Data System (ADS)

    Sabatini, Roberto; Richardson, Mark A.; Gardi, Alessandro; Ramasamy, Subramanian

    2015-11-01

    The underlying principles and technologies enabling the design and operation of airborne laser sensors are introduced and a detailed review of state-of-the-art avionic systems for civil and military applications is presented. Airborne lasers including Light Detection and Ranging (LIDAR), Laser Range Finders (LRF), and Laser Weapon Systems (LWS) are extensively used today and new promising technologies are being explored. Most laser systems are active devices that operate in a manner very similar to microwave radars but at much higher frequencies (e.g., LIDAR and LRF). Other devices (e.g., laser target designators and beam-riders) are used to precisely direct Laser Guided Weapons (LGW) against ground targets. The integration of both functions is often encountered in modern military avionics navigation-attack systems. The beneficial effects of airborne lasers including the use of smaller components and remarkable angular resolution have resulted in a host of manned and unmanned aircraft applications. On the other hand, laser sensors performance are much more sensitive to the vagaries of the atmosphere and are thus generally restricted to shorter ranges than microwave systems. Hence it is of paramount importance to analyse the performance of laser sensors and systems in various weather and environmental conditions. Additionally, it is important to define airborne laser safety criteria, since several systems currently in service operate in the near infrared with considerable risk for the naked human eye. Therefore, appropriate methods for predicting and evaluating the performance of infrared laser sensors/systems are presented, taking into account laser safety issues. For aircraft experimental activities with laser systems, it is essential to define test requirements taking into account the specific conditions for operational employment of the systems in the intended scenarios and to verify the performance in realistic environments at the test ranges. To support the

  17. 76 FR 76333 - Notification for Airborne Wind Energy Systems (AWES)

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-12-07

    ... Federal Aviation Administration 14 CFR Part 77 Notification for Airborne Wind Energy Systems (AWES) AGENCY...,'' to airborne wind energy systems (AWES). In addition, this notice requests information from airborne wind energy system developers and the public related to these systems so that the FAA...

  18. Digital Intermediate Frequency Receiver Module For Use In Airborne Sar Applications

    DOEpatents

    Tise, Bertice L.; Dubbert, Dale F.

    2005-03-08

    A digital IF receiver (DRX) module directly compatible with advanced radar systems such as synthetic aperture radar (SAR) systems. The DRX can combine a 1 G-Sample/sec 8-bit ADC with high-speed digital signal processor, such as high gate-count FPGA technology or ASICs to realize a wideband IF receiver. DSP operations implemented in the DRX can include quadrature demodulation and multi-rate, variable-bandwidth IF filtering. Pulse-to-pulse (Doppler domain) filtering can also be implemented in the form of a presummer (accumulator) and an azimuth prefilter. An out of band noise source can be employed to provide a dither signal to the ADC, and later be removed by digital signal processing. Both the range and Doppler domain filtering operations can be implemented using a unique pane architecture which allows on-the-fly selection of the filter decimation factor, and hence, the filter bandwidth. The DRX module can include a standard VME-64 interface for control, status, and programming. An interface can provide phase history data to the real-time image formation processors. A third front-panel data port (FPDP) interface can send wide bandwidth, raw phase histories to a real-time phase history recorder for ground processing.

  19. System and SAR Characterization in Parallel RF Transmission

    PubMed Central

    Zhu, Yudong; Alon, Leeor; Deniz, Cem M.; Brown, Ryan; Sodickson, Daniel K.

    2011-01-01

    The markedly increased degrees of freedom introduced by parallel RF transmission present both opportunities and challenges for SAR management. On the one hand they enable E field tailoring and SAR reduction while facilitating excitation profile control. On the other hand they increase the complexity of SAR behavior and the risk of inadvertently exacerbating SAR by improper design or playout of RF pulses. The substantial subject-dependency of SAR in high field MR can be a compounding factor. Building upon a linear system concept and a calibration scheme involving a finite number of in situ measurements, the present work establishes a clinically applicable method for characterizing global SAR behavior as well as channel-by-channel power transmission. The method offers a unique capability of predicting, for any excitation, the SAR and power consequences that are specific to the subject to be scanned and the MRI hardware. The method was validated in simulation and experimental studies, showing promise as the foundation to a prospective paradigm where power and SAR are not only monitored but, through prediction-guided optimization, proactively managed. PMID:22139808

  20. New observations of Bolivian wind streaks by JPL Airborne SAR: Preliminary results

    NASA Technical Reports Server (NTRS)

    Blumberg, Dan G.; Greeley, Ronald

    1995-01-01

    In 1993 NASA's Jet Propulsion Laboratory Airborne Synthetic Aperture Radar system (AIRSAR) was deployed to South America to collect multi-parameter radar data over pre-selected targets. Among the sites targeted was a series of wind streaks located in the Altiplano of Bolivia. The objective of this investigation is to study the effect of wavelength, polarization, and incidence angle on the visibility of wind streaks in radar data. Because this is a preliminary evaluation of the recently acquired data we will focus on one scene and, thus, only on the effects of wavelength and polarization. Wind streaks provide information on the near-surface prevailing winds and on the abundance of winderodible material, such as sand. The potential for a free-flyer radar system that could provide global radar images in multiple wavelengths, polarizations, and incidence angles requires definition of system parameters for mission planning. Furthermore, thousands of wind streaks were mapped from Magellan radar images of Venus; their interpretation requires an understanding of the interaction of radar with wind streaks and the surrounding terrain. Our experiment was conducted on wind streaks in the Altiplano of Bolivia to address these issues.

  1. Fourth Airborne Geoscience Workshop

    NASA Technical Reports Server (NTRS)

    1991-01-01

    The focus of the workshop was on how the airborne community can assist in achieving the goals of the Global Change Research Program. The many activities that employ airborne platforms and sensors were discussed: platforms and instrument development; airborne oceanography; lidar research; SAR measurements; Doppler radar; laser measurements; cloud physics; airborne experiments; airborne microwave measurements; and airborne data collection.

  2. Improved Airborne System for Sensing Wildfires

    NASA Technical Reports Server (NTRS)

    McKeown, Donald; Richardson, Michael

    2008-01-01

    The Wildfire Airborne Sensing Program (WASP) is engaged in a continuing effort to develop an improved airborne instrumentation system for sensing wildfires. The system could also be used for other aerial-imaging applications, including mapping and military surveillance. Unlike prior airborne fire-detection instrumentation systems, the WASP system would not be based on custom-made multispectral line scanners and associated custom- made complex optomechanical servomechanisms, sensors, readout circuitry, and packaging. Instead, the WASP system would be based on commercial off-the-shelf (COTS) equipment that would include (1) three or four electronic cameras (one for each of three or four wavelength bands) instead of a multispectral line scanner; (2) all associated drive and readout electronics; (3) a camera-pointing gimbal; (4) an inertial measurement unit (IMU) and a Global Positioning System (GPS) receiver for measuring the position, velocity, and orientation of the aircraft; and (5) a data-acquisition subsystem. It would be necessary to custom-develop an integrated sensor optical-bench assembly, a sensor-management subsystem, and software. The use of mostly COTS equipment is intended to reduce development time and cost, relative to those of prior systems.

  3. CALIOPE airborne CO{sub 2} DIAL (CACDI) system design

    SciTech Connect

    Mietz, D.; Archuleta, B.; Archuleta, J.

    1997-09-01

    Los Alamos National Laboratory is currently developing an airborne CO{sub 2} Differential Absorption Lidar (DIAL) system based on second generation technology demonstrated last summer at NTS. The CALIOPE Airborne CO{sub 2} DIAL (CACDI) system requirements have been compiled based on the mission objectives and SONDIAL model trade studies. Subsystem designs have been developed based on flow down from these system requirements, as well as experience gained from second generation ground tests and N-ABLE (Non-proliferation AirBorne Lidar Experiments) airborne experiments. This paper presents the CACDI mission objectives, system requirements, the current subsystem design, and provides an overview of the airborne experimental plan.

  4. Performance metrics for an airborne imaging system

    NASA Astrophysics Data System (ADS)

    Dayton, David C.; Gonglewski, John D.

    2004-11-01

    A series of airborne imaging experiments have been conducted on the island of Maui and at North Oscura Peak in New Mexico. Two platform altitudes were considered 3000 meters and 600 meters, both with a slant range to the target up to 10000 meters. The airborne imaging platform was a Twin Otter aircraft, which circled ground target sites. The second was a fixed platform on a mountain peak overlooking a valley 600 meters below. The experiments were performed during the day using solar illuminated target buildings. Imaging system performance predictions were calculated using standard atmospheric turbulence models, and aircraft boundary layer models. Several different measurement approaches were then used to estimate the actual system performance, and make comparisons with the calculations.

  5. Airborne HCl - CO sensing system

    NASA Technical Reports Server (NTRS)

    Bartle, E. R.; Hall, G.

    1977-01-01

    A system for measuring air pollutants in-situ using an aircraft was designed, fabricated, and tested. The system is based upon a technique called Gas Filter Correlation (GFC) which provides for high sensitivity and specificity in the presence of interfering species. This particular system was designed for measuring hydrochloric acid and carbon monoxide gases emitted from rocket exhaust effluents.

  6. Airborne Turbulence Warning System Development

    NASA Technical Reports Server (NTRS)

    Bogue, Rod

    2003-01-01

    This viewgraph presentation provides information on the development of a system by which aircraft pilots will be warned of turbulence. This networked system of in situ sensors will be mounted on various aircraft all of which are linked through a ground based parabolic antenna. As its end result, this system will attempt to reduce the number of accidents arising from turbulence.

  7. FlexSAR, a high-quality, flexible, cost-effective, prototype SAR system

    NASA Astrophysics Data System (ADS)

    Jensen, Mark; Knight, Chad; Haslem, Brent

    2015-05-01

    The FlexSAR radar system was designed to be a high quality, low-cost, flexible prototype instrument. Many radar researchers and practitioners desire the ability to efficiently prototype novel configurations. However, the cost and time required to modify existing radar systems is a challenging hurdle that can be prohibitive. The FlexSAR system couples an RF design that leverages connectorized components with digital commercial-off-the-shelf (COTS) cards. This design allows for a scalable system that supports software defined radio (SDR) capabilities. This paper focuses on the RF and digital system design, discussing the advantages and disadvantages. The FlexSAR system design objective was to support diverse configurations with minimal non-recurring engineering (NRE) costs. Multiple diverse applications are examined, demonstrating the flexible system nature. The configurations discussed utilize different system parameters (e.g., number of phase-centers, transmit configurations, etc.). The resultant products are examined, illustrating that high-quality data products are still attained.

  8. Airborne Collision Avoidance System X

    DTIC Science & Technology

    2015-06-01

    avoidance system on behalf of the Federal Aviation Adminis- tration (FAA). The current Traffic Alert and Collision Avoidance System II (TCAS II...which are used on board an aircraft. The tables provide a cost for each action—no alert , a traffic advisory alerting pilots about nearby aircraft, or a...suitabil- ity than does TCAS II; studies show that ACAS X reduces mid-air collision risk by 59% and unnecessary disruptive alerts by 25% when

  9. A prospectus on airborne laser mapping systems

    NASA Technical Reports Server (NTRS)

    Link, L. E.; Krabill, W. B.; Swift, R. N.

    1983-01-01

    Airborne laser systems have demonstrated enormous potential for topographic and bathymetric mapping. Both profiling and scanning systems have been evaluated for terrain elevation mapping, stream valley cross-section determination, and nearshore bottom profiling. Performance of the laser systems has been impressive and for some applications matches current operational accuracy requirements. Determining the position of individual laser measurements remains a constraint for most applications. Laser technology constrains some terrain and bathymetric applications, particularly for water penetration and frequency of measurements for high-spatial resolution over large areas.

  10. Highly Protable Airborne Multispectral Imaging System

    NASA Technical Reports Server (NTRS)

    Lehnemann, Robert; Mcnamee, Todd

    2001-01-01

    A portable instrumentation system is described that includes and airborne and a ground-based subsytem. It can acquire multispectral image data over swaths of terrain ranging in width from about 1.5 to 1 km. The system was developed especially for use in coastal environments and is well suited for performing remote sensing and general environmental monitoring. It includes a small,munpilotaed, remotely controlled airplance that carries a forward-looking camera for navigation, three downward-looking monochrome video cameras for imaging terrain in three spectral bands, a video transmitter, and a Global Positioning System (GPS) reciever.

  11. Airborne Atmospheric Aerosol Measurement System

    NASA Astrophysics Data System (ADS)

    Ahn, K.; Park, Y.; Eun, H.; Lee, H.

    2015-12-01

    It is important to understand the atmospheric aerosols compositions and size distributions since they greatly affect the environment and human health. Particles in the convection layer have been a great concern in global climate changes. To understand these characteristics satellite, aircraft, and radio sonde measurement methods have usually been used. An aircraft aerosol sampling using a filter and/or impactor was the method commonly used (Jay, 2003). However, the flight speed particle sampling had some technical limitations (Hermann, 2001). Moreover, the flight legal limit, altitude, prohibited airspace, flight time, and cost was another demerit. To overcome some of these restrictions, Tethered Balloon Package System (T.B.P.S.) and Recoverable Sonde System(R.S.S.) were developed with a very light optical particle counter (OPC), impactor, and condensation particle counter (CPC). Not only does it collect and measure atmospheric aerosols depending on altitudes, but it also monitors the atmospheric conditions, temperature, humidity, wind velocity, pressure, GPS data, during the measurement (Eun, 2013). In this research, atmospheric aerosol measurement using T.B.P.S. in Ansan area is performed and the measurement results will be presented. The system can also be mounted to an unmanned aerial vehicle (UAV) and create an aerial particle concentration map. Finally, we will present measurement data using Tethered Balloon Package System (T.B.P.S.) and R.S.S (Recoverable Sonde System).

  12. Developing an interactive teleradiology system for SARS diagnosis

    NASA Astrophysics Data System (ADS)

    Sun, Jianyong; Zhang, Jianguo; Zhuang, Jun; Chen, Xiaomeng; Yong, Yuanyuan; Tan, Yongqiang; Chen, Liu; Lian, Ping; Meng, Lili; Huang, H. K.

    2004-04-01

    Severe acute respiratory syndrome (SARS) is a respiratory illness that had been reported in Asia, North America, and Europe in last spring. Most of the China cases of SARS have occurred by infection in hospitals or among travelers. To protect the physicians, experts and nurses from the SARS during the diagnosis and treatment procedures, the infection control mechanisms were built in SARS hospitals. We built a Web-based interactive teleradiology system to assist the radiologists and physicians both in side and out side control area to make image diagnosis. The system consists of three major components: DICOM gateway (GW), Web-based image repository server (Server), and Web-based DICOM viewer (Viewer). This system was installed and integrated with CR, CT and the hospital information system (HIS) in Shanghai Xinhua hospital to provide image-based ePR functions for SARS consultation between the radiologists, physicians and experts inside and out side control area. The both users inside and out side the control area can use the system to process and manipulate the DICOM images interactively, and the system provide the remote control mechanism to synchronize their operations on images and display.

  13. SAR imaging for a forward-looking GPR system

    NASA Astrophysics Data System (ADS)

    Liu, Guoqing; Wang, Yanwei; Li, Jian; Bradley, Marshall R.

    2003-09-01

    We investigate both two-dimensional (2-D) and three-dimensional (3-D) synthetic aperture radar (SAR) imaging techniques for a forward-looking ground penetrating radar (FLGPR) system. In particular, we consider SAR imaging using the delay-and-sum (DAS), phase-shift migration, and spectral estimation (joint APES (Amplitude and Phase EStimation) and RCB (Robust Capon Beamforming)) approaches with the PSI (Planning Systems Inc.) FLGPR Phase II system. For the DAS and phase-shift migration approaches, we use shading in both frequency and cross-track aperture dimensions to reduce sidelobe leakages and clutter. We perform both coherent and non-coherent multi-look processing as well as smoothing to improve the SAR imaging quality and landmine detection capability of the system. The effectiveness of the approaches are demonstrated with an experimental data set collected by the PSI FLGPR Phase II system.

  14. Airborne seeker evaluation and test system

    NASA Astrophysics Data System (ADS)

    Jollie, William B.

    1991-08-01

    The Airborne Seeker Evaluation Test System (ASETS) is an airborne platform for development, test, and evaluation of air-to-ground seekers and sensors. ASETS consists of approximately 10,000 pounds of equipment, including sixteen racks of control, display, and recording electronics, and a very large stabilized airborne turret, all carried by a modified C- 130A aircraft. The turret measures 50 in. in diameter and extends over 50 in. below the aircraft. Because of the low ground clearance of the C-130, a unique retractor mechanism was designed to raise the turret inside the aircraft for take-offs and landings, and deploy the turret outside the aircraft for testing. The turret has over 7 cubic feet of payload space and can accommodate up to 300 pounds of instrumentation, including missile seekers, thermal imagers, infrared mapping systems, laser systems, millimeter wave radar units, television cameras, and laser rangers. It contains a 5-axis gyro-stabilized gimbal system that will maintain a line of sight in the pitch, roll, and yaw axes to an accuracy better than +/- 125 (mu) rad. The rack-mounted electronics in the aircraft cargo bay can be interchanged to operate any type of sensor and record the data. Six microcomputer subsystems operate and maintain all of the system components during a test mission. ASETS is capable of flying at altitudes between 200 and 20,000 feet, and at airspeeds ranging from 100 to 250 knots. Mission scenarios can include air-to-surface seeker testing, terrain mapping, surface target measurement, air-to-air testing, atmospheric transmission studies, weather data collection, aircraft or missile tracking, background signature measurements, and surveillance. ASETS is fully developed and available to support test programs.

  15. High-Level Performance Modeling of SAR Systems

    NASA Technical Reports Server (NTRS)

    Chen, Curtis

    2006-01-01

    SAUSAGE (Still Another Utility for SAR Analysis that s General and Extensible) is a computer program for modeling (see figure) the performance of synthetic- aperture radar (SAR) or interferometric synthetic-aperture radar (InSAR or IFSAR) systems. The user is assumed to be familiar with the basic principles of SAR imaging and interferometry. Given design parameters (e.g., altitude, power, and bandwidth) that characterize a radar system, the software predicts various performance metrics (e.g., signal-to-noise ratio and resolution). SAUSAGE is intended to be a general software tool for quick, high-level evaluation of radar designs; it is not meant to capture all the subtleties, nuances, and particulars of specific systems. SAUSAGE was written to facilitate the exploration of engineering tradeoffs within the multidimensional space of design parameters. Typically, this space is examined through an iterative process of adjusting the values of the design parameters and examining the effects of the adjustments on the overall performance of the system at each iteration. The software is designed to be modular and extensible to enable consideration of a variety of operating modes and antenna beam patterns, including, for example, strip-map and spotlight SAR acquisitions, polarimetry, burst modes, and squinted geometries.

  16. The SIR-C/X-SAR synthetic aperture radar system

    NASA Technical Reports Server (NTRS)

    Jordan, Rolando L.; Huneycutt, Bryan L.; Werner, Marian

    1991-01-01

    SIR-C/X-SAR, a three-frequency radar to be flown on the Space Shuttle in September 1993, is described. The SIR-C system is a two-frequency radar operating at 1250 MHz (L-band) and 5300 MHz (C-band), and is designed to get four-polarization radar imagery at multiple surface angles. The X-SAR system is an X-band imaging radar operating at 9600 MHz. The discussion covers the mission concept; system design; hardware; RF electronics; digital electronics; command, timing, and telemetry; and testing.

  17. Airborne system for testing multispectral reconnaissance technologies

    NASA Astrophysics Data System (ADS)

    Schmitt, Dirk-Roger; Doergeloh, Heinrich; Keil, Heiko; Wetjen, Wilfried

    1999-07-01

    There is an increasing demand for future airborne reconnaissance systems to obtain aerial images for tactical or peacekeeping operations. Especially Unmanned Aerial Vehicles (UAVs) equipped with multispectral sensor system and with real time jam resistant data transmission capabilities are of high interest. An airborne experimental platform has been developed as testbed to investigate different concepts of reconnaissance systems before their application in UAVs. It is based on a Dornier DO 228 aircraft, which is used as flying platform. Great care has been taken to achieve the possibility to test different kinds of multispectral sensors. Hence basically it is capable to be equipped with an IR sensor head, high resolution aerial cameras of the whole optical spectrum and radar systems. The onboard equipment further includes system for digital image processing, compression, coding, and storage. The data are RF transmitted to the ground station using technologies with high jam resistance. The images, after merging with enhanced vision components, are delivered to the observer who has an uplink data channel available to control flight and imaging parameters.

  18. Phase Noise Investigation of Maximum Likelihood Estimation Method for Airborne Multibaseline SAR Interferometry

    NASA Astrophysics Data System (ADS)

    Magnard, C.; Small, D.; Meier, E.

    2015-03-01

    The phase estimation of cross-track multibaseline synthetic aperture interferometric data is usually thought to be very efficiently achieved using the maximum likelihood (ML) method. The suitability of this method is investigated here as applied to airborne single pass multibaseline data. Experimental interferometric data acquired with a Ka-band sensor were processed using (a) a ML method that fuses the complex data from all receivers and (b) a coarse-to-fine method that only uses the intermediate baselines to unwrap the phase values from the longest baseline. The phase noise was analyzed for both methods: in most cases, a small improvement was found when the ML method was used.

  19. Sandia Airspace Recording System (SARS) software reference manual

    SciTech Connect

    Tenney, J.L.

    1996-04-01

    SARS is a data acquisition system designed to gather and process radar data from aircraft flights. A database of flight trajectories has been developed for Albuquerque, NM, and Amarillo, TX. The data is used for safety analysis and risk assessment reports. To support this database effort, Sandia developed a collection of hardware and software tools to collect and post process the aircraft radar data. This document describes the data reduction tools which comprise the SARS, and maintenance procedures for the hardware and software system.

  20. Onboard FPGA-based SAR processing for future spaceborne systems

    NASA Technical Reports Server (NTRS)

    Le, Charles; Chan, Samuel; Cheng, Frank; Fang, Winston; Fischman, Mark; Hensley, Scott; Johnson, Robert; Jourdan, Michael; Marina, Miguel; Parham, Bruce; Rogez, Francois; Rosen, Paul; Shah, Biren; Taft, Stephanie

    2004-01-01

    We present a real-time high-performance and fault-tolerant FPGA-based hardware architecture for the processing of synthetic aperture radar (SAR) images in future spaceborne system. In particular, we will discuss the integrated design approach, from top-level algorithm specifications and system requirements, design methodology, functional verification and performance validation, down to hardware design and implementation.

  1. Investigation of vegetation with multifrequency and multipolarization SAR systems

    NASA Astrophysics Data System (ADS)

    Winter, Rudolf; Roth, Achim; Bayer, Thomas

    1990-05-01

    Investigations of vegetation is conducted by synergism of different types of digital image data and models. As a standard application, satellite images are digitally coregistered with existant topographical data and stored in the Geographic Information Systems (GIS). The usefulness of multiparametric SAR (Synthetic Aperture Radar) data for vegetation mapping is discussed. The multifrequency aspects requires precise geocoding. Different application fields with recent results are discussed: forest investigations with SIR (Spaceborne Imaging Radar)-B data in the southern Rhine valley ; extraction of landuse categories in landscape units using two geocoded Seasat-SAR scenes in the area of Bonn; relief effects on image gray values in geocoded Seasat-SAR images; the concept of a remote sensing data base for ecological applications.

  2. Airborne SAR on circular trajectories to reduce layover and shadow effects of urban scenes

    NASA Astrophysics Data System (ADS)

    Palm, Stephan; Sommer, Rainer; Pohl, Nils; Stilla, Uwe

    2016-10-01

    Circular synthetic aperture radar (CSAR) can provide a full aspect coverage on interesting scenes in one run. Over the city of Karlsruhe a Ka-band dataset was generated in CSAR mode. The data was focused using subapertures in a step of 1.5°, each SAR image representing the scene from a slightly different aspect. The potential of non-coherent fusion of full aspect coverage to reveal small targets was demonstrated. By a manual selection of the viewing angle, parking cars next to high buildings could be revealed and a full view on selected targets with reduced shadow and overlay effects was shown. We studied the effect of varying aspects on the focused image pixels and developed a first metric to automatically select the best viewing angle to a local scene. Areas containing ground information like grass or asphalt and which are not hidden between high objects could be identified and used to deliver a good aspect view on neighboring areas which suffer from shadowing effects.

  3. Airborne remote sensing of forest biomes

    NASA Technical Reports Server (NTRS)

    Sader, Steven A.

    1987-01-01

    Airborne sensor data of forest biomes obtained using an SAR, a laser profiler, an IR MSS, and a TM simulator are presented and examined. The SAR was utilized to investigate forest canopy structures in Mississippi and Costa Rica; the IR MSS measured forest canopy temperatures in Oregon and Puerto Rico; the TM simulator was employed in a tropical forest in Puerto Rico; and the laser profiler studied forest canopy characteristics in Costa Rica. The advantages and disadvantages of airborne systems are discussed. It is noted that the airborne sensors provide measurements applicable to forest monitoring programs.

  4. The Utility and Validity of Kinematic GPS Positioning for the Geosar Airborne Terrain Mapping Radar System

    NASA Technical Reports Server (NTRS)

    Freedman, Adam; Hensley, Scott; Chapin, Elaine; Kroger, Peter; Hussain, Mushtaq; Allred, Bruce

    1999-01-01

    GeoSAR is an airborne, interferometric Synthetic Aperture Radar (IFSAR) system for terrain mapping, currently under development by a consortium including NASA's Jet Propulsion Laboratory (JPL), Calgis, Inc., a California mapping sciences company, and the California Department of Conservation (CaIDOC), with funding provided by the U.S. Army Corps of Engineers Topographic Engineering Center (TEC) and the U.S. Defense Advanced Research Projects Agency (DARPA). IFSAR data processing requires high-accuracy platform position and attitude knowledge. On 9 GeoSAR, these are provided by one or two Honeywell Embedded GPS Inertial Navigation Units (EGI) and an Ashtech Z12 GPS receiver. The EGIs provide real-time high-accuracy attitude and moderate-accuracy position data, while the Ashtech data, post-processed differentially with data from a nearby ground station using Ashtech PNAV software, provide high-accuracy differential GPS positions. These data are optimally combined using a Kalman filter within the GeoSAR motion measurement software, and the resultant position and orientation information are used to process the dual frequency (X-band and P-band) radar data to generate high-accuracy, high -resolution terrain imagery and digital elevation models (DEMs). GeoSAR requirements specify sub-meter level planimetric and vertical accuracies for the resultant DEMS. To achieve this, platform positioning errors well below one meter are needed. The goal of GeoSAR is to obtain 25 cm or better 3-D positions from the GPS systems on board the aircraft. By imaging a set of known point target corner-cube reflectors, the GeoSAR system can be calibrated. This calibration process yields the true position of the aircraft with an uncertainty of 20- 50 cm. This process thus allows an independent assessment of the accuracy of our GPS-based positioning systems. We will present an overview of the GeoSAR motion measurement system, focusing on the use of GPS and the blending of position data from the

  5. Advanced Algorithms and High-Performance Testbed for Large-Scale Site Characterization and Subsurface Target Detecting Using Airborne Ground Penetrating SAR

    NASA Technical Reports Server (NTRS)

    Fijany, Amir; Collier, James B.; Citak, Ari

    1997-01-01

    A team of US Army Corps of Engineers, Omaha District and Engineering and Support Center, Huntsville, let Propulsion Laboratory (JPL), Stanford Research Institute (SRI), and Montgomery Watson is currently in the process of planning and conducting the largest ever survey at the Former Buckley Field (60,000 acres), in Colorado, by using SRI airborne, ground penetrating, Synthetic Aperture Radar (SAR). The purpose of this survey is the detection of surface and subsurface Unexploded Ordnance (UXO) and in a broader sense the site characterization for identification of contaminated as well as clear areas. In preparation for such a large-scale survey, JPL has been developing advanced algorithms and a high-performance restbed for processing of massive amount of expected SAR data from this site. Two key requirements of this project are the accuracy (in terms of UXO detection) and speed of SAR data processing. The first key feature of this testbed is a large degree of automation and a minimum degree of the need for human perception in the processing to achieve an acceptable processing rate of several hundred acres per day. For accurate UXO detection, novel algorithms have been developed and implemented. These algorithms analyze dual polarized (HH and VV) SAR data. They are based on the correlation of HH and VV SAR data and involve a rather large set of parameters for accurate detection of UXO. For each specific site, this set of parameters can be optimized by using ground truth data (i.e., known surface and subsurface UXOs). In this paper, we discuss these algorithms and their successful application for detection of surface and subsurface anti-tank mines by using a data set from Yuma proving Ground, A7, acquired by SRI SAR.

  6. A multiprocessor airborne lidar data system

    NASA Technical Reports Server (NTRS)

    Wright, C. W.; Bailey, S. A.; Heath, G. E.; Piazza, C. R.

    1988-01-01

    A new multiprocessor data acquisition system was developed for the existing Airborne Oceanographic Lidar (AOL). This implementation simultaneously utilizes five single board 68010 microcomputers, the UNIX system V operating system, and the real time executive VRTX. The original data acquisition system was implemented on a Hewlett Packard HP 21-MX 16 bit minicomputer using a multi-tasking real time operating system and a mixture of assembly and FORTRAN languages. The present collection of data sources produce data at widely varied rates and require varied amounts of burdensome real time processing and formatting. It was decided to replace the aging HP 21-MX minicomputer with a multiprocessor system. A new and flexible recording format was devised and implemented to accommodate the constantly changing sensor configuration. A central feature of this data system is the minimization of non-remote sensing bus traffic. Therefore, it is highly desirable that each micro be capable of functioning as much as possible on-card or via private peripherals. The bus is used primarily for the transfer of remote sensing data to or from the buffer queue.

  7. A multiprocessor airborne lidar data system

    NASA Astrophysics Data System (ADS)

    Wright, C. W.; Bailey, S. A.; Heath, G. E.; Piazza, C. R.

    A new multiprocessor data acquisition system was developed for the existing Airborne Oceanographic Lidar (AOL). This implementation simultaneously utilizes five single board 68010 microcomputers, the UNIX system V operating system, and the real time executive VRTX. The original data acquisition system was implemented on a Hewlett Packard HP 21-MX 16 bit minicomputer using a multi-tasking real time operating system and a mixture of assembly and FORTRAN languages. The present collection of data sources produce data at widely varied rates and require varied amounts of burdensome real time processing and formatting. It was decided to replace the aging HP 21-MX minicomputer with a multiprocessor system. A new and flexible recording format was devised and implemented to accommodate the constantly changing sensor configuration. A central feature of this data system is the minimization of non-remote sensing bus traffic. Therefore, it is highly desirable that each micro be capable of functioning as much as possible on-card or via private peripherals. The bus is used primarily for the transfer of remote sensing data to or from the buffer queue.

  8. An approach to evaluating reactive airborne wind shear systems

    NASA Technical Reports Server (NTRS)

    Gibson, Joseph P., Jr.

    1992-01-01

    An approach to evaluating reactive airborne windshear detection systems was developed to support a deployment study for future FAA ground-based windshear detection systems. The deployment study methodology assesses potential future safety enhancements beyond planned capabilities. The reactive airborne systems will be an integral part of planned windshear safety enhancements. The approach to evaluating reactive airborne systems involves separate analyses for both landing and take-off scenario. The analysis estimates the probability of effective warning considering several factors including NASA energy height loss characteristics, reactive alert timing, and a probability distribution for microburst strength.

  9. Advanced airborne ISR demonstration system (USA)

    NASA Astrophysics Data System (ADS)

    Henry, Daniel J.

    2005-05-01

    Recon/Optical, Inc. (ROI) is developing an advanced airborne Intelligence, Surveillance, and Reconnaissance (ISR) demonstration system based upon the proven ROI technology used in the SHAred Reconnaissance Pod (SHARP) for the U.S. Navy F/A-18. The demonstration system, which includes several state-of-the-art technology enhancements for next-generation ISR, is scheduled for flight testing in the summer of 2005. The demonstration system contains a variant of the SHARP medium altitude CA-270 camera, comprising an inertially stabilized Visible/NIR 5Kx5K imager and MWIR 2Kx2K imager to provide simultaneous high resolution/wide area coverage dual-band operation. The imager has been upgraded to incorporate a LN-100G GPS/INS within the sensor passive isolation loop to improve the accuracy of the NITF image metadata. The Image Processor is also based upon the SHARP configuration, but the demo system contains several enhancements including increased image processing horsepower, Ethernet-based Command & Control, next-generation JPEG2000 image compression, JPEG2000 Interactive Protocol (JPIP) network data server/client architecture, bi-directional RF datalink, advanced image dissemination/exploitation, and optical Fibrechannel I/O to the solid state recorder. This paper describes the ISR demonstration system and identifies the new network centric CONOPS made possible by the technology enhancements.

  10. Miniaturized Airborne Imaging Central Server System

    NASA Technical Reports Server (NTRS)

    Sun, Xiuhong

    2011-01-01

    In recent years, some remote-sensing applications require advanced airborne multi-sensor systems to provide high performance reflective and emissive spectral imaging measurement rapidly over large areas. The key or unique problem of characteristics is associated with a black box back-end system that operates a suite of cutting-edge imaging sensors to collect simultaneously the high throughput reflective and emissive spectral imaging data with precision georeference. This back-end system needs to be portable, easy-to-use, and reliable with advanced onboard processing. The innovation of the black box backend is a miniaturized airborne imaging central server system (MAICSS). MAICSS integrates a complex embedded system of systems with dedicated power and signal electronic circuits inside to serve a suite of configurable cutting-edge electro- optical (EO), long-wave infrared (LWIR), and medium-wave infrared (MWIR) cameras, a hyperspectral imaging scanner, and a GPS and inertial measurement unit (IMU) for atmospheric and surface remote sensing. Its compatible sensor packages include NASA s 1,024 1,024 pixel LWIR quantum well infrared photodetector (QWIP) imager; a 60.5 megapixel BuckEye EO camera; and a fast (e.g. 200+ scanlines/s) and wide swath-width (e.g., 1,920+ pixels) CCD/InGaAs imager-based visible/near infrared reflectance (VNIR) and shortwave infrared (SWIR) imaging spectrometer. MAICSS records continuous precision georeferenced and time-tagged multisensor throughputs to mass storage devices at a high aggregate rate, typically 60 MB/s for its LWIR/EO payload. MAICSS is a complete stand-alone imaging server instrument with an easy-to-use software package for either autonomous data collection or interactive airborne operation. Advanced multisensor data acquisition and onboard processing software features have been implemented for MAICSS. With the onboard processing for real time image development, correction, histogram-equalization, compression, georeference, and

  11. Temporal multiparameter airborne DLR E-SAR images for crop monitoring: summary of the CLEOPATRA campaign 1992

    NASA Astrophysics Data System (ADS)

    Schmullius, Christiane C.; Nithack, Juergen

    1997-01-01

    From May 11 to July 31, 1992 the Cloud Experiment OberPfaffenhofen And Transports took place as a field experimental contribution to the global energy and water cycle experiment. The DLR Institute of Radio Frequency Technology participated with its experimental SAR system E- SAR. Multitemporal X-, C- and L-band data from 8 dates and three ERS-1 images between May 20 and July 30, 1992 are analyzed in regard to the influence of changing plant backscatter constituents and to investigate the impact of increasing ground cover in the different wavelength on soil moisture mapping. Backscatter curves of four crops are shown, which indicate the possibility for crop monitoring and preferred times for crop classification. Detection of soil moisture changes is only possible with L-band and only under grain crops. Maximum likelihood and isocluster classifications were applied on several single- and multifrequency, mono- and multitemporal channel combinations. The overall classification accuracies were higher than with supervised methods. Maximum likelihood classification allowed identification of ten crop types with accuracies of up to 84 percent, when a temporal multifrequency data set was used.

  12. Helicopter Airborne Laser Positioning System (HALPS)

    NASA Technical Reports Server (NTRS)

    Eppel, Joseph C.; Christiansen, Howard; Cross, Jeffrey; Totah, Joseph

    1990-01-01

    The theory of operation, configuration, laboratory, and ground test results obtained with a helicopter airborne laser positioning system developed by Princeton University is presented. Unfortunately, due to time constraints, flight data could not be completed for presentation at this time. The system measures the relative position between two aircraft in three dimensions using two orthogonal fan-shaped laser beams sweeping across an array of four detectors. Specifically, the system calculates the relative range, elevation, and azimuth between an observation aircraft and a test helicopter with a high degree of accuracy. The detector array provides a wide field of view in the presence of solar interference due to compound parabolic concentrators and spectral filtering of the detector pulses. The detected pulses and their associated time delays are processed by the electronics and are sent as position errors to the helicopter pilot who repositions the aircraft as part of the closed loop system. Accuracies obtained in the laboratory at a range of 80 ft in the absence of sunlight were + or - 1 deg in elevation; +0.5 to -1.5 deg in azimuth; +0.5 to -1.0 ft in range; while elevation varied from 0 to +28 deg and the azimuth varied from 0 to + or - 45 deg. Accuracies in sunlight were approximately 40 deg (+ or - 20 deg) in direct sunlight.

  13. Estimation of Boreal Forest Biomass Using Spaceborne SAR Systems

    NASA Technical Reports Server (NTRS)

    Saatchi, Sassan; Moghaddam, Mahta

    1995-01-01

    In this paper, we report on the use of a semiempirical algorithm derived from a two layer radar backscatter model for forest canopies. The model stratifies the forest canopy into crown and stem layers, separates the structural and biometric attributes of the canopy. The structural parameters are estimated by training the model with polarimetric SAR (synthetic aperture radar) data acquired over homogeneous stands with known above ground biomass. Given the structural parameters, the semi-empirical algorithm has four remaining parameters, crown biomass, stem biomass, surface soil moisture, and surface rms height that can be estimated by at least four independent SAR measurements. The algorithm has been used to generate biomass maps over the entire images acquired by JPL AIRSAR and SIR-C SAR systems. The semi-empirical algorithms are then modified to be used by single frequency radar systems such as ERS-1, JERS-1, and Radarsat. The accuracy. of biomass estimation from single channel radars is compared with the case when the channels are used together in synergism or in a polarimetric system.

  14. Development of a new airborne humidigraph system.

    SciTech Connect

    Pekour, Mikhail S.; Schmid, Beat; Chand, Duli; Hubbe, John M.; Kluzek, Celine D.; Nelson, Danny A.; Tomlinson, Jason M.; Cziczo, Daniel J.

    2012-12-06

    Modeling and measurements of aerosol properties is complicated by the hygroscopic behavior of the aerosols adding significant uncertainty to our best estimates of the direct effect aerosols exert on the radiative balance of the atmosphere. Airborne measurements of aerosol hygroscopicity are particularly challenging but critically needed. This motivated the development of a newly designed system which can measure the dependence of the aerosol light scattering coefficient (σsp) on relative humidity (RH), known as f(RH), in real-time at a rapid rate (<10 s) on an aerial platform. The new system has several advantages over existing systems. It consists of three integrating nephelometers and humidity conditioners for simultaneous measurement of the σsp at three different RHs. The humidity is directly controlled in exchanger cells without significant temperature disturbances and without particle dilution, heating or loss of volatile compounds. The single-wavelength nephelometers are illuminated by LED-based light sources thereby minimizing heating of the sample stream. The flexible design of the RH conditioners, consisting of a number of specially designed exchanger cells (driers or humidifiers), enables us to measure f(RH) under hydration or dehydration conditions (always starting with the aerosol in a known state) with a simple system re-configuration. These exchanger cells have been characterized for losses of particles using latex spheres and laboratory generated ammonium sulfate aerosols. Residence times of 6 - 9 s in the exchangers and subsequent lines is sufficient for most aerosols to attain equilibrium with the new water vapor content. The performance of this system has been assessed aboard DOE’s G-1 research aircraft during test flights over California, Oregon, and Washington.

  15. Assessment of lightweight mobile nuclear power systems. [for airborne vehicles

    NASA Technical Reports Server (NTRS)

    Anderson, J. L.; Rom, F. E.

    1973-01-01

    A review was made of lightweight mobile nuclear power systems (LMNPS). Data cover technical feasibility studies of LMNPS and airborne vehicles, mission studies, and non-technical conditions that are required to develop and use LMNPS.

  16. Safety analysis and review system (SARS) assessment report

    SciTech Connect

    Browne, E.T.

    1981-03-01

    Under DOE Order 5481.1, Safety Analysis and Review System for DOE Operations, safety analyses are required for DOE projects in order to ensure that: (1) potential hazards are systematically identified; (2) potential impacts are analyzed; (3) reasonable measures have been taken to eliminate, control, or mitigate the hazards; and (4) there is documented management authorization of the DOE operation based on an objective assessment of the adequacy of the safety analysis. This report is intended to provide the DOE Office of Plans and Technology Assessment (OPTA) with an independent evaluation of the adequacy of the ongoing safety analysis effort. As part of this effort, a number of site visits and interviews were conducted, and FE SARS documents were reviewed. The latter included SARS Implementation Plans for a number of FE field offices, as well as safety analysis reports completed for certain FE operations. This report summarizes SARS related efforts at the DOE field offices visited and evaluates the extent to which they fulfill the requirements of DOE 5481.1.

  17. An integrated compact airborne multispectral imaging system using embedded computer

    NASA Astrophysics Data System (ADS)

    Zhang, Yuedong; Wang, Li; Zhang, Xuguo

    2015-08-01

    An integrated compact airborne multispectral imaging system using embedded computer based control system was developed for small aircraft multispectral imaging application. The multispectral imaging system integrates CMOS camera, filter wheel with eight filters, two-axis stabilized platform, miniature POS (position and orientation system) and embedded computer. The embedded computer has excellent universality and expansibility, and has advantages in volume and weight for airborne platform, so it can meet the requirements of control system of the integrated airborne multispectral imaging system. The embedded computer controls the camera parameters setting, filter wheel and stabilized platform working, image and POS data acquisition, and stores the image and data. The airborne multispectral imaging system can connect peripheral device use the ports of the embedded computer, so the system operation and the stored image data management are easy. This airborne multispectral imaging system has advantages of small volume, multi-function, and good expansibility. The imaging experiment results show that this system has potential for multispectral remote sensing in applications such as resource investigation and environmental monitoring.

  18. Galaxy: a new state of the art airborne lidar system

    NASA Astrophysics Data System (ADS)

    Hartsell, Daryl; LaRocque, Paul E.; Tripp, Jeffrey

    2016-10-01

    Recent advancements in lidar technologies have led to significant improvements in Teledyne Optech's airborne lidar systems. This paper will present the performance enhancements that have led to the creation of the Galaxy, a compact scanning lidar system. Unlike the previous generation of conventional airborne lidar, the Galaxy offers fundamentally improved specifications for long-range airborne lidar systems. The Galaxy system is capable of acquiring high-density, multiple-return data with unique pulse separation characteristics and exceptional precision. Utilizing discrete time-of-flight measurement electronics, this new system is capable of seamlessly operating at very high laser repetition rates through blind zones and with multiple pulses in the air. By utilizing even higher scan products , the system outperforms previous generations of systems and optimizes point density during collection.

  19. Plans for the development of EOS SAR systems using the Alaska SAR facility. [Earth Observing System (EOS)

    NASA Technical Reports Server (NTRS)

    Carsey, F. D.; Weeks, W.

    1988-01-01

    The Alaska SAR Facility (ASF) program for the acquisition and processing of data from the ESA ERS-1, the NASDA ERS-1, and Radarsat and to carry out a program of science investigations using the data is introduced. Agreements for data acquisition and analysis are in place except for the agreement between NASA and Radarsat which is in negotiation. The ASF baseline system, consisting of the Receiving Ground System, the SAR Processor System and the Archive and Operations System, passed critical design review and is fully in implementation phase. Augments to the baseline system for systems to perform geophysical processing and for processing of J-ERS-1 optical data are in the design and implementation phase. The ASF provides a very effective vehicle with which to prepare for the Earth Observing System (EOS) in that it will aid the development of systems and technologies for handling the data volumes produced by the systems of the next decades, and it will also supply some of the data types that will be produced by EOS.

  20. Airborne water vapor DIAL research: System development and field measurements

    NASA Technical Reports Server (NTRS)

    Higdon, Noah S.; Browell, Edward V.; Ponsardin, Patrick; Chyba, Thomas H.; Grossmann, Benoist E.; Butler, Carolyn F.; Fenn, Marta A.; Mayor, Shane D.; Ismail, Syed; Grant, William B.

    1992-01-01

    This paper describes the airborne differential absorption lidar (DIAL) system developed at the NASA Langley Research Center for remote measurement of water vapor (H2O) and aerosols in the lower atmosphere. The airborne H2O DIAL system was flight tested aboard the NASA Wallops Flight Facility (WFF) Electra aircraft in three separate field deployments between 1989 and 1991. Atmospheric measurements were made under a variety of atmospheric conditions during the flight tests, and several modifications were implemented during this development period to improve system operation. A brief description of the system and major modifications will be presented, and the most significant atmospheric observations will be described.

  1. Airborne Multisensor Pod System, Arms control and nonproliferation technologies: Second quarter 1995

    SciTech Connect

    Alonzo, G M; Sanford, N M

    1995-01-01

    This issue focuses on the Airborne Multisensor Pod System (AMPS) which is a collaboration of many of the DOE national laboratories to provide a scientific environment to research multiple sensors and the new information that can be derived from them. The bulk of the research has been directed at nonproliferation applications, but it has also proven useful in environmental monitoring and assessment, and land/water management. The contents of this issue are: using AMPS technology to detect proliferation and monitor resources; combining multisensor data to monitor facilities and natural resources; planning a AMPS mission; SAR pod produces images day or night, rain or shine; MSI pod combines data from multiple sensors; ESI pod will analyze emissions and effluents; and accessing AMPS information on the Internet.

  2. Airborne Collision Avoidance Systems and Air Traffic Management Safety

    NASA Astrophysics Data System (ADS)

    Brooker, Peter

    2005-01-01

    A new ICAO Policy on Airborne Collision Avoidance Systems is needed, which recognizes it to be an integrated part of the air traffic management system's safety defences; and that should be fully included in hazard analyses for the total system's design safety targets.

  3. Land mine detection with an ultra-wideband SAR system

    NASA Astrophysics Data System (ADS)

    Andrieu, Joel; Gallais, Frederic; Mallepeyre, Vincent; Bertrand, Valerie; Beillard, Bruno; Jecko, Bernard; Guillerey, Regis; Legoff, Marc

    2002-08-01

    PULSAR is an Ultra Wide Band (UWB) short pulse Radar developed by the CELAR (French Technical Center for Armament Electronics) and the IRCOM (Research Institute of Microwave and Optical Communications) in order to detect foliage and ground concealed mines. An instrumentation measurement system has been designed and implemented, in particular new 2D broad band antennas with a very low pulse distortion. The clutter suppression is based on background subtraction and wavelet transforms. These data are used to obtain SAR ultra wide band images by transient methods. The following discussion describes the device, the experimental results and the signal processing currently utilized. Future development efforts on this system (generator, acquisition means .) are detailed. At the same time a theoretical study is made to estimate target transient responses captured by the system. So a FDTD code is modified to simulate buried objects detection by the radar.

  4. An airborne four-camera imaging system for agricultural applications

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This paper describes the design and testing of an airborne multispectral digital imaging system for remote sensing applications. The system consists of four high resolution charge coupled device (CCD) digital cameras and a ruggedized PC equipped with a frame grabber and image acquisition software. T...

  5. Assessment of documentation requirements under DOE 5481. 1, Safety Analysis and Review System (SARS)

    SciTech Connect

    Browne, E.T.

    1981-03-01

    This report assesses the requirements of DOE Order 5481.1, Safety Analysis and Review System for DOE Operations (SARS) in regard to maintaining SARS documentation. Under SARS, all pertinent details of the entire safety analysis and review process for each DOE operation are to be traceable from the initial identification of a hazard. This report is intended to provide assistance in identifying the points in the SARS cycle at which documentation is required, what type of documentation is most appropriate, and where it ultimately should be maintained.

  6. Advanced Airborne Hyperspectral Imaging System (AAHIS)

    NASA Astrophysics Data System (ADS)

    Topping, Miles Q.; Pfeiffer, Joel E.; Sparks, Andrew W.; Jim, Kevin T. C.; Yoon, Dugan

    2002-11-01

    The design, operation, and performance of the fourth generation of Science and Technology International's Advanced Airborne Hyperspectral Imaging Sensors (AAHIS) are described. These imaging spectrometers have a variable bandwidth ranging from 390-840 nm. A three-axis image stabilization provides spatially and spectrally coherent imagery by damping most of the airborne platform's random motion. A wide 40-degree field of view coupled with sub-pixel detection allows for a large area coverage rate. A software controlled variable aperture, spectral shaping filters, and high quantum efficiency, back-illuminated CCD's contribute to the excellent sensitivity of the sensors. AAHIS sensors have been operated on a variety of fixed and rotary wing platforms, achieving ground-sampling distances ranging from 6.5 cm to 2 m. While these sensors have been primarily designed for use over littoral zones, they are able to operate over both land and water. AAHIS has been used for detecting and locating submarines, mines, tanks, divers, camouflage and disturbed earth. Civilian applications include search and rescue on land and at sea, agricultural analysis, environmental time-series, coral reef assessment, effluent plume detection, coastal mapping, damage assessment, and seasonal whale population monitoring

  7. Formal methods and digital systems validation for airborne systems

    NASA Technical Reports Server (NTRS)

    Rushby, John

    1993-01-01

    This report has been prepared to supplement a forthcoming chapter on formal methods in the FAA Digital Systems Validation Handbook. Its purpose is as follows: to outline the technical basis for formal methods in computer science; to explain the use of formal methods in the specification and verification of software and hardware requirements, designs, and implementations; to identify the benefits, weaknesses, and difficulties in applying these methods to digital systems used on board aircraft; and to suggest factors for consideration when formal methods are offered in support of certification. These latter factors assume the context for software development and assurance described in RTCA document DO-178B, 'Software Considerations in Airborne Systems and Equipment Certification,' Dec. 1992.

  8. Low cost airborne microwave landing system receiver, task 3

    NASA Technical Reports Server (NTRS)

    Hager, J. B.; Vancleave, J. R.

    1979-01-01

    Work performed on the low cost airborne Microwave Landing System (MLS) receiver is summarized. A detailed description of the prototype low cost MLS receiver is presented. This detail includes block diagrams, schematics, board assembly drawings, photographs of subassemblies, mechanical construction, parts lists, and microprocessor software. Test procedures are described and results are presented.

  9. A real-time focused SAR algorithm on the Jetson TK1 board

    NASA Astrophysics Data System (ADS)

    Radecki, K.; Samczynski, P.; Kulpa, K.; Drozdowicz, J.

    2016-10-01

    In this paper the authors present a solution based on a small and lightweight computing platform equipped with a graphics processing unit (GPU) which allows the possibility of performing a real-time fully focused SAR algorithm. The presented system is dedicated for airborne SAR applications including small SAR systems dedicated for medium-sized unmanned aerial vehicle (UAV) platforms. The proposed solution also reduces the need for a storage system. In the paper real SAR results obtained using a Frequency Modulation Continuous Wave (FMCW) radar demonstrator operating at 35 GHz carrier frequency with 1GHz bandwidth are presented. As a radar carrier an airborne platform was used. The presented SAR radar demonstrator was developed by the Warsaw University of Technology in cooperation with the Air Force Institute of Technology, Warsaw, Poland.

  10. Design and implementation of digital airborne multispectral camera system

    NASA Astrophysics Data System (ADS)

    Lin, Zhaorong; Zhang, Xuguo; Wang, Li; Pan, Deai

    2012-10-01

    The multispectral imaging equipment is a kind of new generation remote sensor, which can obtain the target image and the spectra information simultaneously. A digital airborne multispectral camera system using discrete filter method had been designed and implemented for unmanned aerial vehicle (UAV) and manned aircraft platforms. The digital airborne multispectral camera system has the advantages of larger frame, higher resolution, panchromatic and multispectral imaging. It also has great potential applications in the fields of environmental and agricultural monitoring and target detection and discrimination. In order to enhance the measurement precision and accuracy of position and orientation, Inertial Measurement Unit (IMU) is integrated in the digital airborne multispectral camera. Meanwhile, the Temperature Control Unit (TCU) guarantees that the camera can operate in the normal state in different altitudes to avoid the window fogging and frosting which will degrade the imaging quality greatly. Finally, Flying experiments were conducted to demonstrate the functionality and performance of the digital airborne multispectral camera. The resolution capability, positioning accuracy and classification and recognition ability were validated.

  11. Airborne system for multispectral, multiangle polarimetric imaging.

    PubMed

    Bowles, Jeffrey H; Korwan, Daniel R; Montes, Marcos J; Gray, Deric J; Gillis, David B; Lamela, Gia M; Miller, W David

    2015-11-01

    In this paper, we describe the design, fabrication, calibration, and deployment of an airborne multispectral polarimetric imager. The motivation for the development of this instrument was to explore its ability to provide information about water constituents, such as particle size and type. The instrument is based on four 16 MP cameras and uses wire grid polarizers (aligned at 0°, 45°, 90°, and 135°) to provide the separation of the polarization states. A five-position filter wheel provides for four narrow-band spectral filters (435, 550, 625, and 750 nm) and one blocked position for dark-level measurements. When flown, the instrument is mounted on a programmable stage that provides control of the view angles. View angles that range to ±65° from the nadir have been used. Data processing provides a measure of the polarimetric signature as a function of both the view zenith and view azimuth angles. As a validation of our initial results, we compare our measurements, over water, with the output of a Monte Carlo code, both of which show neutral points off the principle plane. The locations of the calculated and measured neutral points are compared. The random error level in the measured degree of linear polarization (8% at 435) is shown to be better than 0.25%.

  12. Present and Future Airborne and Space-Borne Systems

    DTIC Science & Technology

    2005-02-01

    Riegger, I. Hajnsek, D. Hounam, G. Krieger, A. Moreira,M. Werner: Single-Pass SAR Interferometry with a Tandem TerraSAR-X Configuration Mittermayer ...September 2002. Mittermayer J., Lord R., Boerner E., “Sliding Spotlight SAR Processing for TerraSAR-X Using a New Formulation of the Extended Chirp...Scaling Algorithm”, proc. IGARSS 2003, Toulouse, 2003, in press. Mittermayer J., Runge H., “Conceptual Studies for Exploiting the TerraSAR-X Dual

  13. Towards a Multi-Mission, Airborne Science Data System Environment

    NASA Astrophysics Data System (ADS)

    Crichton, D. J.; Hardman, S.; Law, E.; Freeborn, D.; Kay-Im, E.; Lau, G.; Oswald, J.

    2011-12-01

    NASA earth science instruments are increasingly relying on airborne missions. However, traditionally, there has been limited common infrastructure support available to principal investigators in the area of science data systems. As a result, each investigator has been required to develop their own computing infrastructures for the science data system. Typically there is little software reuse and many projects lack sufficient resources to provide a robust infrastructure to capture, process, distribute and archive the observations acquired from airborne flights. At NASA's Jet Propulsion Laboratory (JPL), we have been developing a multi-mission data system infrastructure for airborne instruments called the Airborne Cloud Computing Environment (ACCE). ACCE encompasses the end-to-end lifecycle covering planning, provisioning of data system capabilities, and support for scientific analysis in order to improve the quality, cost effectiveness, and capabilities to enable new scientific discovery and research in earth observation. This includes improving data system interoperability across each instrument. A principal characteristic is being able to provide an agile infrastructure that is architected to allow for a variety of configurations of the infrastructure from locally installed compute and storage services to provisioning those services via the "cloud" from cloud computer vendors such as Amazon.com. Investigators often have different needs that require a flexible configuration. The data system infrastructure is built on the Apache's Object Oriented Data Technology (OODT) suite of components which has been used for a number of spaceborne missions and provides a rich set of open source software components and services for constructing science processing and data management systems. In 2010, a partnership was formed between the ACCE team and the Carbon in Arctic Reservoirs Vulnerability Experiment (CARVE) mission to support the data processing and data management needs

  14. Integration of TerraSAR-X, RapidEye and airborne lidar for remote sensing of intertidal bedforms on the upper flats of Norderney (German Wadden Sea)

    NASA Astrophysics Data System (ADS)

    Adolph, Winny; Jung, Richard; Schmidt, Alena; Ehlers, Manfred; Heipke, Christian; Bartholomä, Alexander; Farke, Hubert

    2016-11-01

    The Wadden Sea is a large coastal transition area adjoining the southern North Sea uniting ecological key functions with an important role in coastal protection. The region is strictly protected by EU directives and national law and is a UNESCO World Heritage Site, requiring frequent quality assessments and regular monitoring. In 2014 an intertidal bedform area characterised by alternating crests and water-covered troughs on the tidal flats of the island of Norderney (German Wadden Sea sector) was chosen to test different remote sensing methods for habitat mapping: airborne lidar, satellite-based radar (TerraSAR-X) and electro-optical sensors (RapidEye). The results revealed that, although sensitive to different surface qualities, all sensors were able to image the bedforms. A digital terrain model generated from the lidar data shows crests and slopes of the bedforms with high geometric accuracy in the centimetre range, but high costs limit the operation area. TerraSAR-X data enabled identifying the positions of the bedforms reflecting the residual water in the troughs also with a high resolution of up to 1.1 m, but with larger footprints and much higher temporal availability. RapidEye data are sensitive to differences in sediment moisture employed to identify crest areas, slopes and troughs, with high spatial coverage but the lowest resolution (6.5 m). Monitoring concepts may differ in their remote sensing requirements regarding areal coverage, spatial and temporal resolution, sensitivity and geometric accuracy. Also financial budgets limit the selection of sensors. Thus, combining differing assets into an integrated concept of remote sensing contributes to solving these issues.

  15. Integration of TerraSAR-X, RapidEye and airborne lidar for remote sensing of intertidal bedforms on the upper flats of Norderney (German Wadden Sea)

    NASA Astrophysics Data System (ADS)

    Adolph, Winny; Jung, Richard; Schmidt, Alena; Ehlers, Manfred; Heipke, Christian; Bartholomä, Alexander; Farke, Hubert

    2017-04-01

    The Wadden Sea is a large coastal transition area adjoining the southern North Sea uniting ecological key functions with an important role in coastal protection. The region is strictly protected by EU directives and national law and is a UNESCO World Heritage Site, requiring frequent quality assessments and regular monitoring. In 2014 an intertidal bedform area characterised by alternating crests and water-covered troughs on the tidal flats of the island of Norderney (German Wadden Sea sector) was chosen to test different remote sensing methods for habitat mapping: airborne lidar, satellite-based radar (TerraSAR-X) and electro-optical sensors (RapidEye). The results revealed that, although sensitive to different surface qualities, all sensors were able to image the bedforms. A digital terrain model generated from the lidar data shows crests and slopes of the bedforms with high geometric accuracy in the centimetre range, but high costs limit the operation area. TerraSAR-X data enabled identifying the positions of the bedforms reflecting the residual water in the troughs also with a high resolution of up to 1.1 m, but with larger footprints and much higher temporal availability. RapidEye data are sensitive to differences in sediment moisture employed to identify crest areas, slopes and troughs, with high spatial coverage but the lowest resolution (6.5 m). Monitoring concepts may differ in their remote sensing requirements regarding areal coverage, spatial and temporal resolution, sensitivity and geometric accuracy. Also financial budgets limit the selection of sensors. Thus, combining differing assets into an integrated concept of remote sensing contributes to solving these issues.

  16. Covariance analysis of the airborne laser ranging system

    NASA Technical Reports Server (NTRS)

    Englar, T. S., Jr.; Hammond, C. L.; Gibbs, B. P.

    1981-01-01

    The requirements and limitations of employing an airborne laser ranging system for detecting crustal shifts of the Earth within centimeters over a region of approximately 200 by 400 km are presented. The system consists of an aircraft which flies over a grid of ground deployed retroreflectors, making six passes over the grid at two different altitudes. The retroreflector baseline errors are assumed to result from measurement noise, a priori errors on the aircraft and retroreflector positions, tropospheric refraction, and sensor biases.

  17. Indoor Unmanned Airship System Airborne Control Module Design

    NASA Astrophysics Data System (ADS)

    YongXia, Gao; YiBo, Li

    By adopting STC12C5A60S2 SCM as a system control unit, assisted by appropriate software and hardware resources, we complete the airborne control module's design of unmanned airship system. This paper introduces hardware control module's structure, airship-driven composition and software realization. Verified by the China Science and Technology Museum special-shaped airship,this control module can work well.

  18. The position and orientation system (POS) for airborne survey applications

    SciTech Connect

    Reid, B.; Scherzinger, B.; Lithopoulos, E.

    1996-10-01

    The Position and Orientation System (POS) is an integrated inertial/GPS system that generates accurate position (latitude, longitude, altitude) and orientation (roll, pitch, heading) for airborne survey/mapping applications as well as various other land and marine applications. POS is a GPS-aided strapdown inertial navigator that uses a Kalman filter and a closed-loop error controller to provide an optimally blended position and orientation solution from inertial data from an IMU and aiding data from a GPS receiver. This paper gives a brief description of POS and compares it to other available technologies. It then describes the various application areas of POS for airborne vehicles (POS/AV). Some applications from other POS variants, POS/LV for Land Vehicles, POS/MV for Marine Vessels, are also described. 4 refs., 4 figs., 1 tab.

  19. An airborne system for detection of volcanic surface deformations

    NASA Technical Reports Server (NTRS)

    Lunine, J.

    1980-01-01

    A technique is proposed for measuring volcanic deformation on the order of centimeters per day to centimeters per year. An airborne multifrequency pulsed radar, tracking passive ground reflectors spaced at 1 kilometer intervals over a 50 square kilometer area is employed. Identification of targets is accomplished by Doppler and range resolution techniques, with final relative position measurements accomplished by phase comparison of multifrequency signals. Atmospheric path length errors are corrected by an airborne refractometer, meteorological instruments, or other refractive index measuring devices. Anticipated system accuracy is 1-2 cm, with measuring times on the order of minutes. Potential problems exist in the high intrinsic data assimilation rate required of the system to overcome ground backscatter noise.

  20. Inter-agency Working Group for Airborne Data and Telemetry Systems (IWGADTS)

    NASA Technical Reports Server (NTRS)

    Webster, Chris; Freudinger, Lawrence; Sorenson, Carl; Myers, Jeff; Sullivan, Don; Oolman, Larry

    2009-01-01

    The Interagency Coordinating Committee for Airborne Geosciences Research and Applications (ICCAGRA) was established to improve cooperation and communication among agencies sponsoring airborne platforms and instruments for research and applications, and to serve as a resource for senior level management on airborne geosciences issues. The Interagency Working Group for Airborne Data and Telecommunications Systems (IWGADTS) is a subgroup to ICCAGRA for the purpose of developing recommendations leading to increased interoperability among airborne platforms and instrument payloads, producing increased synergy among research programs with similar goals, and enabling the suborbital layer of the Global Earth Observing System of Systems.

  1. Airborne antenna polarization study for the microwave landing system

    NASA Technical Reports Server (NTRS)

    Gilreath, M. C.

    1976-01-01

    The feasibility of the microwave landing system (MLS) airborne antenna pattern coverage requirements are investigated for a large commercial aircraft using a single omnidirectional antenna. Omnidirectional antennas having vertical and horizontal polarizations were evaluated at several different station locations on a one-eleventh scale model Boeing 737 aircraft. The results obtained during this experimental program are presented which include principal plane antenna patterns and complete volumetric coverage plots.

  2. Compact Superconducting Power Systems for Airborne Applications (Postprint)

    DTIC Science & Technology

    2009-01-01

    Timothy J. Haugan, George A. Levin, and Edward B. Durkin Power Generation Branch Power Division JANUARY 2009 Approved...AND ADDRESS(ES) 8. PERFORMING ORGANIZATION Power Generation Branch (AFRL/RZPG) . REPORT NUMBER Power Division AFRL-RZ-WP-TP-2010-2061 Air Force...future airborne megawatt-class power generation , it is important to minimize both the size and the weight of the system. The primary means of

  3. On the use of L-band multipolarization airborne SAR for surveys of crops, vineyards, and orchards in a California irrigated agricultural region

    NASA Technical Reports Server (NTRS)

    Paris, J. F.

    1985-01-01

    The airborne L-band synthetic aperture radar (SAR) collected multipolarization calibrated image data over an irrigated agricultural test site near Fresno, CA, on March 6, 1984. The conclusions of the study are as follows: (1) the effects of incidence angle on the measured backscattering coefficients could be removed by using a correction factor equal to the secant of the angle raised to the 1.4 power, (2) for this scene and time of year, the various polarization channels were highly correlated such that the use of more than one polarization added little to the ability of the radar to discriminate vegetation type or condition; the exception was barley which separated from vineyards only when a combination of like and cross polarization data were used (polarization was very useful for corn identification in fall crops), (3) an excellent separation between herbaceous vegetation (alfalfa, barley, and oats) or bare fields and trees in orchards existed in brightness was well correlated to alfalfa height or biomass, especially for the HH polarization combination, (5) vineyards exhibited a narrow range of brightnesses with no systematic effects of type or number of stakes nor of number of wires in the trellises nor of the size of the vines, (6) within the orchard classes, areal biomass characterized by basal area differences caused radar image brightness differences for small to medium trees but not for medium to large trees.

  4. Algorithms used in the Airborne Lidar Processing System (ALPS)

    USGS Publications Warehouse

    Nagle, David B.; Wright, C. Wayne

    2016-05-23

    The Airborne Lidar Processing System (ALPS) analyzes Experimental Advanced Airborne Research Lidar (EAARL) data—digitized laser-return waveforms, position, and attitude data—to derive point clouds of target surfaces. A full-waveform airborne lidar system, the EAARL seamlessly and simultaneously collects mixed environment data, including submerged, sub-aerial bare earth, and vegetation-covered topographies.ALPS uses three waveform target-detection algorithms to determine target positions within a given waveform: centroid analysis, leading edge detection, and bottom detection using water-column backscatter modeling. The centroid analysis algorithm detects opaque hard surfaces. The leading edge algorithm detects topography beneath vegetation and shallow, submerged topography. The bottom detection algorithm uses water-column backscatter modeling for deeper submerged topography in turbid water.The report describes slant range calculations and explains how ALPS uses laser range and orientation measurements to project measurement points into the Universal Transverse Mercator coordinate system. Parameters used for coordinate transformations in ALPS are described, as are Interactive Data Language-based methods for gridding EAARL point cloud data to derive digital elevation models. Noise reduction in point clouds through use of a random consensus filter is explained, and detailed pseudocode, mathematical equations, and Yorick source code accompany the report.

  5. NASA three-laser airborne differential absorption lidar system electronics

    NASA Technical Reports Server (NTRS)

    Allen, R. J.; Copeland, G. D.

    1984-01-01

    The system control and signal conditioning electronics of the NASA three laser airborne differential absorption lidar (DIAL) system are described. The multipurpose DIAL system was developed for the remote measurement of gas and aerosol profiles in the troposphere and lower stratosphere. A brief description and photographs of the majority of electronics units developed under this contract are presented. The precision control system; which includes a master control unit, three combined NASA laser control interface/quantel control units, and three noise pulse discriminator/pockels cell pulser units; is described in detail. The need and design considerations for precision timing and control are discussed. Calibration procedures are included.

  6. Development of an airborne remote sensing system for crop pest management: System integration and verification

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Remote sensing along with Global Positioning Systems, Geographic Information Systems, and variable rate technology has been developed, which scientists can implement to help farmers maximize the economic and environmental benefits of crop pest management through precision agriculture. Airborne remo...

  7. Airborne Advanced Reconfigurable Computer System (ARCS)

    NASA Technical Reports Server (NTRS)

    Bjurman, B. E.; Jenkins, G. M.; Masreliez, C. J.; Mcclellan, K. L.; Templeman, J. E.

    1976-01-01

    A digital computer subsystem fault-tolerant concept was defined, and the potential benefits and costs of such a subsystem were assessed when used as the central element of a new transport's flight control system. The derived advanced reconfigurable computer system (ARCS) is a triple-redundant computer subsystem that automatically reconfigures, under multiple fault conditions, from triplex to duplex to simplex operation, with redundancy recovery if the fault condition is transient. The study included criteria development covering factors at the aircraft's operation level that would influence the design of a fault-tolerant system for commercial airline use. A new reliability analysis tool was developed for evaluating redundant, fault-tolerant system availability and survivability; and a stringent digital system software design methodology was used to achieve design/implementation visibility.

  8. Airborne water vapor DIAL system development

    NASA Technical Reports Server (NTRS)

    Higdon, Noah S.; Browell, Edward V.; Ponsardin, Patrick; Grossmann, Benoist E.

    1990-01-01

    A differential absorption lidar (DIAL) system developed at NASA Langley Research Center for the remote measurement of atmospheric H2O and aerosols from an aircraft is briefly discussed. This DIAL system utilizes a Nd:YAG laser-pumped dye laser as the off-line transmitter and a narrowband, tunable Alexandrite laser as the on-line transmitter. A 1-m monochromator and a multipass absorption cell are used to position the on-line laser to the center of the H2O line. The receiver system has a 14-in. diameter, f/7 Celestron telescope to collect the backscattered laser light and focus in into the detector optics. Return signals are converted to electrical signals by the optical detector and are digitalized and stored on magnetic tape. The results of fligh tests of the system are shown.

  9. Phased-array radar for airborne systems

    NASA Astrophysics Data System (ADS)

    Tahim, Raghbir S.; Foshee, James J.; Chang, Kai

    2003-09-01

    Phased array antenna systems, which support high pulse rates and high transmit power, are well suited for radar and large-scale surveillance. Sensors and communication systems can function as the eyes and ears for ballistic missile defense applications, providing early warning of attack, target detection and identification, target tracking, and countermeasure decision. In such applications, active array radar systems that contain solid-state transmitter sources and low-noise preamplifiers for transmission and reception are preferred over the conventional radar antennas, because the phased array radar offers the advantages of power management and efficiency, reliability, signal reception, beam steering target detection. The current phased array radar designs are very large, complex and expensive and less efficient because of high RF losses in the phase control circuits used for beam scan. Several thousands of phase shifters and drivers may be required for a single system thus making the system very complex and expensive. This paper describes the phased array radar system based on high power T/R modules, wide-band radiating planar antenna elements and very low loss wide-band phase control circuits (requiring reduced power levels) for beam scan. The phase shifter design is based on micro-strip feed lines perturbed by the proximity of voltage controlled piezoelectric transducer (PET). Measured results have shown an added insertion loss of less than 1 dB for a phase shift of 450 degrees from 2 to 20 GHz. The new wideband phased array radar design provides significant reduction in size cost and weight. Compared to the conventional phased array systems, the cost saving is more than 15 to 1.

  10. Instrumentation Development of an Airborne Recording System.

    DTIC Science & Technology

    1978-01-01

    calculator and suitable peripheral equipment. Accelerometer time histories from an analog recorder are digitized and processed on the programmable calculator system...spectral data in support of materiel air transportability and air delivery testing missions. The new data processing is based on a programmable

  11. Demonstration and Validation of an Improved Airborne Electromagnetic System for UXO Detection and Mapping

    DTIC Science & Technology

    2010-05-01

    basalt flows or other iron-bearing soils and rocks impede the performance of magnetometer systems. Although this is not a universal problem, it occurs...sensors at less than 0.5 m above ground level (AGL). Airborne and ground magnetometer systems are susceptible to interference from magnetic rocks and...where magnetite bearing basaltic rocks are problematic. The airborne TEM-8 system demonstrates a similar advantage over airborne magnetometer systems

  12. Recent modifications, enhancements, and measurements with an airborne lidar system

    NASA Astrophysics Data System (ADS)

    DeCoursey, Robert J.; Osborn, Mary T.; Winker, David M.; Woods, David C.

    1996-06-01

    The NASA Langley Research Center's 14-inch airborne aerosol lidar system, which is routinely flown on several NASA aircraft including the DC-8 and the P-3, has been upgraded with several modifications to enhance its measurement capabilities. A new 900 mJ, 10 pps Nd:YAG laser was added with the capability of producing 5 watts of power at 1064 nm, 2.5 watts at 532 nm and 1.5 watts at 355 nm. The existing detector package has been modified to accommodate the three wavelengths and to permit cross-polarization measurements at 532 nm. New software was developed for on- line data visualization and analysis, and computer- controlled laser alignment is being incorporated. The system is now capable of producing real-time color modulated backscatter plots. Other additions include a Pentium/90 processor, GPS (Global Positioning System) and ARINC (Aeronautical Radio Inc.) receivers for acquiring accurate aircraft position data. In 1992 and 1993 this system was flown on several airborne missions to map and characterize the stratospheric aerosol cloud produced by the 1991 eruption of the Mount Pinatubo volcano. Efforts to map the global distribution of Pinatubo were made on both daytime as well as nighttime flights from Moffett Field in California to the South Pacific, to Central and South America, to Australia and to Alaska. In September 1994, the system (aboard NASA's P-3) made correlative measurements along shuttle orbit ground tracks in support of the Lidar In-space Technology Experiment flown on the Space Shuttle. In this paper the system upgrades will be discussed and selected data obtained during these recent airborne campaigns will be presented.

  13. FM-CW Based Miniature SAR Systems for Small UAVs

    DTIC Science & Technology

    2005-05-01

    interest in developing a spaceborne P-band SAR, small angles of incidence are preferred. The six major types of forest to be observed are palm oil ... deforestation and land use change these areas are at risk and are already producing enormous carbon emissions (through oxidation and fire). These emissions

  14. Airborne Tomographic Swath Ice Sounding Processing System

    NASA Technical Reports Server (NTRS)

    Wu, Xiaoqing; Rodriquez, Ernesto; Freeman, Anthony; Jezek, Ken

    2013-01-01

    Glaciers and ice sheets modulate global sea level by storing water deposited as snow on the surface, and discharging water back into the ocean through melting. Their physical state can be characterized in terms of their mass balance and dynamics. To estimate the current ice mass balance, and to predict future changes in the motion of the Greenland and Antarctic ice sheets, it is necessary to know the ice sheet thickness and the physical conditions of the ice sheet surface and bed. This information is required at fine resolution and over extensive portions of the ice sheets. A tomographic algorithm has been developed to take raw data collected by a multiple-channel synthetic aperture sounding radar system over a polar ice sheet and convert those data into two-dimensional (2D) ice thickness measurements. Prior to this work, conventional processing techniques only provided one-dimensional ice thickness measurements along profiles.

  15. Confirmation of quasi-static approximation in SAR evaluation for a wireless power transfer system

    NASA Astrophysics Data System (ADS)

    Hirata, Akimasa; Ito, Fumihiro; Laakso, Ilkka

    2013-09-01

    The present study discusses the applicability of the magneto-quasi-static approximation to the calculation of the specific absorption rate (SAR) in a cylindrical model for a wireless power transfer system. Resonant coils with different parameters were considered in the 10 MHz band. A two-step quasi-static method that is comprised of the method of moments and the scalar-potential finite-difference methods is applied, which can consider the effects of electric and magnetic fields on the induced SAR separately. From our computational results, the SARs obtained from our quasi-static method are found to be in good agreement with full-wave analysis for different positions of the cylindrical model relative to the wireless power transfer system, confirming the applicability of the quasi-static approximation in the 10 MHz band. The SAR induced by the external electric field is found to be marginal as compared to that induced by the magnetic field. Thus, the dosimetry for the external magnetic field, which may be marginally perturbed by the presence of biological tissue, is confirmed to be essential for SAR compliance in the 10 MHz band or lower. This confirmation also suggests that the current in the coil rather than the transferred power is essential for SAR compliance.

  16. Confirmation of quasi-static approximation in SAR evaluation for a wireless power transfer system.

    PubMed

    Hirata, Akimasa; Ito, Fumihiro; Laakso, Ilkka

    2013-09-07

    The present study discusses the applicability of the magneto-quasi-static approximation to the calculation of the specific absorption rate (SAR) in a cylindrical model for a wireless power transfer system. Resonant coils with different parameters were considered in the 10 MHz band. A two-step quasi-static method that is comprised of the method of moments and the scalar-potential finite-difference methods is applied, which can consider the effects of electric and magnetic fields on the induced SAR separately. From our computational results, the SARs obtained from our quasi-static method are found to be in good agreement with full-wave analysis for different positions of the cylindrical model relative to the wireless power transfer system, confirming the applicability of the quasi-static approximation in the 10 MHz band. The SAR induced by the external electric field is found to be marginal as compared to that induced by the magnetic field. Thus, the dosimetry for the external magnetic field, which may be marginally perturbed by the presence of biological tissue, is confirmed to be essential for SAR compliance in the 10 MHz band or lower. This confirmation also suggests that the current in the coil rather than the transferred power is essential for SAR compliance.

  17. Roads Centre-Axis Extraction in Airborne SAR Images: AN Approach Based on Active Contour Model with the Use of Semi-Automatic Seeding

    NASA Astrophysics Data System (ADS)

    Lotte, R. G.; Sant'Anna, S. J. S.; Almeida, C. M.

    2013-05-01

    Research works dealing with computational methods for roads extraction have considerably increased in the latest two decades. This procedure is usually performed on optical or microwave sensors (radar) imagery. Radar images offer advantages when compared to optical ones, for they allow the acquisition of scenes regardless of atmospheric and illumination conditions, besides the possibility of surveying regions where the terrain is hidden by the vegetation canopy, among others. The cartographic mapping based on these images is often manually accomplished, requiring considerable time and effort from the human interpreter. Maps for detecting new roads or updating the existing roads network are among the most important cartographic products to date. There are currently many studies involving the extraction of roads by means of automatic or semi-automatic approaches. Each of them presents different solutions for different problems, making this task a scientific issue still open. One of the preliminary steps for roads extraction can be the seeding of points belonging to roads, what can be done using different methods with diverse levels of automation. The identified seed points are interpolated to form the initial road network, and are hence used as an input for an extraction method properly speaking. The present work introduces an innovative hybrid method for the extraction of roads centre-axis in a synthetic aperture radar (SAR) airborne image. Initially, candidate points are fully automatically seeded using Self-Organizing Maps (SOM), followed by a pruning process based on specific metrics. The centre-axis are then detected by an open-curve active contour model (snakes). The obtained results were evaluated as to their quality with respect to completeness, correctness and redundancy.

  18. A multisensor system for airborne surveillance of oil pollution

    NASA Technical Reports Server (NTRS)

    Edgerton, A. T.; Ketchal, R.; Catoe, C.

    1973-01-01

    The U.S. Coast Guard is developing a prototype airborne oil surveillance system for use in its Marine Environmental Protection Program. The prototype system utilizes an X-band side-looking radar, a 37-GHz imaging microwave radiometer, a multichannel line scanner, and a multispectral low light level system. The system is geared to detecting and mapping oil spills and potential pollution violators anywhere within a 25 nmi range of the aircraft flight track under all but extreme weather conditions. The system provides for false target discrimination and maximum identification of spilled materials. The system also provides an automated detection alarm, as well as a color display to achieve maximum coupling between the sensor data and the equipment operator.

  19. An airborne remote sensing system for urban air quality

    NASA Technical Reports Server (NTRS)

    Duncan, L. J.; Friedman, E. J.; Keitz, E. L.; Ward, E. A.

    1974-01-01

    Several NASA sponsored remote sensors and possible airborne platforms were evaluated. Outputs of dispersion models for SO2 and CO pollution in the Washington, D.C. area were used with ground station data to establish the expected performance and limitations of the remote sensors. Aircraft/sensor support requirements are discussed. A method of optimum flight plan determination was made. Cost trade offs were performed. Conclusions about the implementation of various instrument packages as parts of a comprehensive air quality monitoring system in Washington are presented.

  20. Some applications of the turbulence amplifier to airborne systems

    NASA Astrophysics Data System (ADS)

    Taylor, D. L.

    1981-06-01

    The turbulence amplifier relies on the disruption of a laminar air stream by a small actuating signal that consists of a transverse jet. The dynamic pressure head, generated by the passage of an aircraft through the atmosphere will provide sufficient supply pressure at 130 mph and sufficient control pressure at 30 mph. This means that, in certain applications, no external power source is required, which is of significant interest to airborne applications. As a result of this feature, three systems were investigated for practicability. A description is presented of the development and performance of laboratory models of these three applications. An ice detection and de-icing control system was designed to sense icing conditions on a wing leading edge, and to use the sensed data to operate a de-icing control system. A demonstration model for a control surface asymmetry detection and rectification system was built, and a stall warning system was studied.

  1. Present and Future Airborne and Space-borne Systems

    DTIC Science & Technology

    2007-02-01

    subsidence by means of differential SAR interferometry, In Proc. IGARSS03, Toulouse. Mittermayer J., Alberga V., Buckreuss S., Riegger S...TerraSAR-X: Predicted Performance”, Proc. SPIE2002, Vol. 4881, Agia Pelagia, Crete, Greece, 22 - 27 September 2002. Mittermayer J., Lord R., Boerner E...in press. Mittermayer J., Runge H., “Conceptual Studies for Exploiting the TerraSAR-X Dual Receiving Antenna”, proc. IGARSS 2003, Toulouse, 2003. R

  2. Airborne Systems Technology Application to the Windshear Threat

    NASA Technical Reports Server (NTRS)

    Arbuckle, P. Douglas; Lewis, Michael S.; Hinton, David A.

    1996-01-01

    The general approach and products of the NASA/FAA Airborne Windshear Program conducted by NASA Langley Research Center are summarized, with references provided for the major technical contributions. During this period, NASA conducted 2 years of flight testing to characterize forward-looking sensor performance. The NASA/FAA Airborne Windshear Program was divided into three main elements: Hazard Characterization, Sensor Technology, and Flight Management Systems. Simulation models developed under the Hazard Characterization element are correlated with flight test data. Flight test results comparing the performance and characteristics of the various Sensor Technologies (microwave radar, lidar, and infrared) are presented. Most of the activities in the Flight Management Systems element were conducted in simulation. Simulation results from a study evaluating windshear crew procedures and displays for forward-looking sensor-equipped airplanes are discussed. NASA Langley researchers participated heavily in the FAA process of generating certification guidelines for predictive windshear detection systems. NASA participants felt that more valuable technology products were generated by the program because of this interaction. NASA involvement in the process and the resulting impact on products and technology transfer are discussed in this paper.

  3. MARA (Multimode Airborne Radar Altimeter) system documentation. Volume 1: MARA system requirements document

    NASA Astrophysics Data System (ADS)

    Parsons, C. L.

    1989-07-01

    The Multimode Airborne Radar Altimeter (MARA), a flexible airborne radar remote sensing facility developed by NASA's Goddard Space Flight Center, is discussed. This volume describes the scientific justification for the development of the instrument and the translation of these scientific requirements into instrument design goals. Values for key instrument parameters are derived to accommodate these goals, and simulations and analytical models are used to estimate the developed system's performance.

  4. MARA (Multimode Airborne Radar Altimeter) system documentation. Volume 1: MARA system requirements document

    NASA Technical Reports Server (NTRS)

    Parsons, C. L. (Editor)

    1989-01-01

    The Multimode Airborne Radar Altimeter (MARA), a flexible airborne radar remote sensing facility developed by NASA's Goddard Space Flight Center, is discussed. This volume describes the scientific justification for the development of the instrument and the translation of these scientific requirements into instrument design goals. Values for key instrument parameters are derived to accommodate these goals, and simulations and analytical models are used to estimate the developed system's performance.

  5. Airborne experiment results for spaceborne atmospheric synchronous correction system

    NASA Astrophysics Data System (ADS)

    Cui, Wenyu; Yi, Weining; Du, Lili; Liu, Xiao

    2015-10-01

    The image quality of optical remote sensing satellite is affected by the atmosphere, thus the image needs to be corrected. Due to the spatial and temporal variability of atmospheric conditions, correction by using synchronous atmospheric parameters can effectively improve the remote sensing image quality. For this reason, a small light spaceborne instrument, the atmospheric synchronous correction device (airborne prototype), is developed by AIOFM of CAS(Anhui Institute of Optics and Fine Mechanics of Chinese Academy of Sciences). With this instrument, of which the detection mode is timing synchronization and spatial coverage, the atmospheric parameters consistent with the images to be corrected in time and space can be obtained, and then the correction is achieved by radiative transfer model. To verify the technical process and treatment effect of spaceborne atmospheric correction system, the first airborne experiment is designed and completed. The experiment is implemented by the "satellite-airborne-ground" synchronous measuring method. A high resolution(0.4 m) camera and the atmospheric correction device are equipped on the aircraft, which photograph the ground with the satellite observation over the top simultaneously. And aerosol optical depth (AOD) and columnar water vapor (CWV) in the imagery area are also acquired, which are used for the atmospheric correction for satellite and aerial images. Experimental results show that using the AOD and CWV of imagery area retrieved by the data obtained by the device to correct aviation and satellite images, can improve image definition and contrast by more than 30%, and increase MTF by more than 1 time, which means atmospheric correction for satellite images by using the data of spaceborne atmospheric synchronous correction device is accurate and effective.

  6. An airborne meteorological data collection system using satellite relay (ASDAR)

    NASA Technical Reports Server (NTRS)

    Bagwell, J. W.; Lindow, B. G.

    1978-01-01

    The National Aeronautics and Space Administration (NASA) has developed an airborne data acquisition and communication system for the National Oceanic and Atmospheric Administration (NOAA). This system known as ASDAR, the Aircraft to Satellite Data Relay, consists of a microprocessor based controller, time clock, transmitter and antenna. Together they acquire meteorological and position information from existing aircraft systems on B-747 aircraft, convert and format these, and transmit them to the ground via the GOES meteorological satellite series. The development and application of the ASDAR system is described with emphasis on unique features. Performance to date is exceptional, providing horizon-to-horizon coverage of aircraft flights. The data collected is of high quality and is considered a valuable addition to the data base from which NOAA generates its weather forecasts.

  7. SAR System for UAV Operation with Motion Error Compensation beyond the Resolution Cell

    PubMed Central

    González-Partida, José-Tomás; Almorox-González, Pablo; Burgos-García, Mateo; Dorta-Naranjo, Blas-Pablo

    2008-01-01

    This paper presents an experimental Synthetic Aperture Radar (SAR) system that is under development in the Universidad Politécnica de Madrid. The system uses Linear Frequency Modulated Continuous Wave (LFM-CW) radar with a two antenna configuration for transmission and reception. The radar operates in the millimeter-wave band with a maximum transmitted bandwidth of 2 GHz. The proposed system is being developed for Unmanned Aerial Vehicle (UAV) operation. Motion errors in UAV operation can be critical. Therefore, this paper proposes a method for focusing SAR images with movement errors larger than the resolution cell. Typically, this problem is solved using two processing steps: first, coarse motion compensation based on the information provided by an Inertial Measuring Unit (IMU); and second, fine motion compensation for the residual errors within the resolution cell based on the received raw data. The proposed technique tries to focus the image without using data of an IMU. The method is based on a combination of the well known Phase Gradient Autofocus (PGA) for SAR imagery and typical algorithms for translational motion compensation on Inverse SAR (ISAR). This paper shows the first real experiments for obtaining high resolution SAR images using a car as a mobile platform for our radar. PMID:27879884

  8. SAR System for UAV Operation with Motion Error Compensation beyond the Resolution Cell.

    PubMed

    González-Partida, José-Tomás; Almorox-González, Pablo; Burgos-Garcia, Mateo; Dorta-Naranjo, Blas-Pablo

    2008-05-23

    This paper presents an experimental Synthetic Aperture Radar (SAR) system that is under development in the Universidad Politécnica de Madrid. The system uses Linear Frequency Modulated Continuous Wave (LFM-CW) radar with a two antenna configuration for transmission and reception. The radar operates in the millimeter-wave band with a maximum transmitted bandwidth of 2 GHz. The proposed system is being developed for Unmanned Aerial Vehicle (UAV) operation. Motion errors in UAV operation can be critical. Therefore, this paper proposes a method for focusing SAR images with movement errors larger than the resolution cell. Typically, this problem is solved using two processing steps: first, coarse motion compensation based on the information provided by an Inertial Measuring Unit (IMU); and second, fine motion compensation for the residual errors within the resolution cell based on the received raw data. The proposed technique tries to focus the image without using data of an IMU. The method is based on a combination of the well known Phase Gradient Autofocus (PGA) for SAR imagery and typical algorithms for translational motion compensation on Inverse SAR (ISAR). This paper shows the first real experiments for obtaining high resolution SAR images using a car as a mobile platform for our radar.

  9. A human in vitro model system for investigating genome-wide host responses to SARS coronavirus infection

    PubMed Central

    Ng, Lisa FP; Hibberd, Martin L; Ooi, Eng-Eong; Tang, Kin-Fai; Neo, Soek-Ying; Tan, Jenny; Krishna Murthy, Karuturi R; Vega, Vinsensius B; Chia, Jer-Ming; Liu, Edison T; Ren, Ee-Chee

    2004-01-01

    Background The molecular basis of severe acute respiratory syndrome (SARS) coronavirus (CoV) induced pathology is still largely unclear. Many SARS patients suffer respiratory distress brought on by interstitial infiltration and frequently show peripheral blood lymphopenia and occasional leucopenia. One possible cause of this could be interstitial inflammation, following a localized host response. In this study, we therefore examine the immune response of SARS-CoV in human peripheral blood mononuclear cells (PBMCs) over the first 24 hours. Methods PBMCs from normal healthy donors were inoculated in vitro with SARS-CoV and the viral replication kinetics was studied by real-time quantitative assays. SARS-CoV specific gene expression changes were examined by high-density oligonucleotide array analysis. Results We observed that SARS-CoV was capable of infecting and replicating in PBMCs and the kinetics of viral replication was variable among the donors. SARS-CoV antibody binding assays indicated that SARS specific antibodies inhibited SARS-CoV viral replication. Array data showed monocyte-macrophage cell activation, coagulation pathway upregulation and cytokine production together with lung trafficking chemokines such as IL8 and IL17, possibly activated through the TLR9 signaling pathway; that mimicked clinical features of the disease. Conclusions The identification of human blood mononuclear cells as a direct target of SARS-CoV in the model system described here provides a new insight into disease pathology and a tool for investigating the host response and mechanisms of pathogenesis. PMID:15357874

  10. The airborne laser ranging system, its capabilities and applications

    NASA Technical Reports Server (NTRS)

    Kahn, W. D.; Degnan, J. J.; Englar, T. S., Jr.

    1982-01-01

    The airborne laser ranging system is a multibeam short pulse laser ranging system on board an aircraft. It simultaneously measures the distances between the aircraft and six laser retroreflectors (targets) deployed on the Earth's surface. The system can interrogate over 100 targets distributed over an area of 25,000 sq, kilometers in a matter of hours. Potentially, a total of 1.3 million individual range measurements can be made in a six hour flight. The precision of these range measurements is approximately + or - 1 cm. These measurements are used in procedure which is basically an extension of trilateration techniques to derive the intersite vector between the laser ground targets. By repeating the estimation of the intersite vector, strain and strain rate errors can be estimated. These quantities are essential for crustal dynamic studies which include determination and monitoring of regional strain in the vicinity of active fault zones, land subsidence, and edifice building preceding volcanic eruptions.

  11. On the Implementation of a Land Cover Classification System for SAR Images Using Khoros

    NASA Technical Reports Server (NTRS)

    Medina Revera, Edwin J.; Espinosa, Ramon Vasquez

    1997-01-01

    The Synthetic Aperture Radar (SAR) sensor is widely used to record data about the ground under all atmospheric conditions. The SAR acquired images have very good resolution which necessitates the development of a classification system that process the SAR images to extract useful information for different applications. In this work, a complete system for the land cover classification was designed and programmed using the Khoros, a data flow visual language environment, taking full advantages of the polymorphic data services that it provides. Image analysis was applied to SAR images to improve and automate the processes of recognition and classification of the different regions like mountains and lakes. Both unsupervised and supervised classification utilities were used. The unsupervised classification routines included the use of several Classification/Clustering algorithms like the K-means, ISO2, Weighted Minimum Distance, and the Localized Receptive Field (LRF) training/classifier. Different texture analysis approaches such as Invariant Moments, Fractal Dimension and Second Order statistics were implemented for supervised classification of the images. The results and conclusions for SAR image classification using the various unsupervised and supervised procedures are presented based on their accuracy and performance.

  12. STAP for SAR

    DTIC Science & Technology

    2003-04-01

    UNCLASSIFIED Defense Technical Information Center Compilation Part Notice ADP014042 TITLE: STAP for SAR DISTRIBUTION: Approved for public release...compilation report: ADP014040 thru ADP014047 UNCLASSIFIED 3-1 STAP for SAR A. Farina Technical Directorate, Radar & Technology Division Alenia...Adaptive Processing) to Synthetic Aperture Radar ( SAR ) systems. SAR is a microwave sensor that allows us to have a high resolution mapping of

  13. PacRIM II: A review of AirSAR operations and system performance

    NASA Technical Reports Server (NTRS)

    Moller, D.; Chu, A.; Lou, Y.; Miller, T.; O'Leary, E.

    2001-01-01

    In this paper we briefly review the AirSAR system, its expected performance, and quality of data obtained during that mission. We discuss the system hardware calibration methodologies, and present quantitative performance values of radar backscatter and interferometric height errors (random and systematic) from PACRIM II calibration data.

  14. Airborne Multisensor Pod System (AMPS) data management overview

    SciTech Connect

    Wiberg, J.D.; Blough, D.K.; Daugherty, W.R.; Hucks, J.A.; Gerhardstein, L.H.; Meitzler, W.D.; Melton, R.B.; Shoemaker, S.V.

    1994-09-01

    An overview of the Data Management Plan for the Airborne Multisensor Pod System (AMPS) pro-grain is provided in this document. The Pacific Northwest Laboratory (PNL) has been assigned the responsibility of data management for the program, which includes defining procedures for data management and data quality assessment. Data management is defined as the process of planning, acquiring, organizing, qualifying and disseminating data. The AMPS program was established by the U.S. Department of Energy (DOE), Office of Arms Control and Non-Proliferation (DOE/AN) and is integrated into the overall DOE AN-10.1 technology development program. Sensors used for collecting the data were developed under the on-site inspection, effluence analysis, and standoff sensor program, the AMPS program interacts with other technology programs of DOE/NN-20. This research will be conducted by both government and private industry. AMPS is a research and development program, and it is not intended for operational deployment, although the sensors and techniques developed could be used in follow-on operational systems. For a complete description of the AMPS program, see {open_quotes}Airborne Multisensor Pod System (AMPS) Program Plan{close_quotes}. The primary purpose of the AMPS is to collect high-quality multisensor data to be used in data fusion research to reduce interpretation problems associated with data overload and to derive better information than can be derived from any single sensor. To collect the data for the program, three wing-mounted pods containing instruments with sensors for collecting data will be flight certified on a U.S. Navy RP-3A aircraft. Secondary objectives of the AMPS program are sensor development and technology demonstration. Pod system integrators and instrument developers will be interested in the performance of their deployed sensors and their supporting data acquisition equipment.

  15. Fusion of LADAR with SAR for precision strike

    SciTech Connect

    Cress, D.H.; Muguira, M.R.

    1995-03-01

    This paper presents a concept for fusing 3-dimensional image reconnaissance data with LADAR imagery for aim point refinement. The approach is applicable to fixed or quasi-fixed targets. Quasi-fixed targets are targets that are not expected to be moved between the time of reconnaissance and the time of target engagement. The 3-dimensional image data is presumed to come from standoff reconnaissance assets tens to hundreds of kilometers from the target area or acquisitions prior to hostilities. Examples are synthetic aperture radar (SAR) or stereoprocessed satellite imagery. SAR can be used to generate a 3-dimensional map of the surface through processing of data acquired with conventional SAR acquired using two closely spaced, parallel reconnaissance paths, either airborne or satellite based. Alternatively, a specialized airborne SAR having two receiving antennas may be used for data acquisition. The data sets used in this analysis are: (1) LADAR data acquired using a Hughes-Danbury system flown over a portion of Kirtland AFB during the period September 15--16, 1993; (2) two pass interferometric SAR data flown over a terrain-dominated area of Kirtland AFB; (3) 3-dimensional mapping of an urban-dominated area of the Sandia National Laboratories and adjacent cultural area extracted from aerial photography by Vexcel Corporation; (4) LADAR data acquired at Eglin AFB under Wright Laboratory`s Advanced Technology Ladar System (ATLAS) program using a 60 {mu}J, 75 KHz Co{sub 2} laser; and (5) two pass interferometric SAR data generated by Sandia`s STRIP DCS (Data Collection System) radar corresponding to the ATLAS LADAR data. The cultural data set was used in the urban area rather than SAR because high quality interferometric SAR data were not available for the urban-type area.

  16. How second generation SAR systems are impacting the analysis of ground deformation

    NASA Astrophysics Data System (ADS)

    Sansosti, E.; Berardino, P.; Bonano, M.; Calò, F.; Castaldo, R.; Casu, F.; Manunta, M.; Manzo, M.; Pepe, A.; Pepe, S.; Solaro, G.; Tizzani, P.; Zeni, G.; Lanari, R.

    2014-05-01

    In recent years, a second generation of Synthetic Aperture Radar (SAR) satellite sensor has been designed and, partially, put into operation, leading to an important breakthrough in Earth Science studies. The common characteristics of such new systems are, indeed, a reduced revisit time (as short as a few days) and, in most cases, an improved spatial resolution (as small as a few meters), providing scientists with unprecedented data for the mapping and monitoring of natural and human-induced hazards. This paper provides an overview on the new observational capability offered by the second generation of SAR sensors, especially in the field of ground deformation analysis for mitigating the risk associated with natural and human-induced hazards. In particular, we exploit the high resolution X-band data acquired by the COSMO-SkyMed (CSK) constellation to show how deformation phenomena characterized by limited spatial extent and extremely fast dynamics can be detected and investigated in details. Whenever possible, we compare the achieved results with those obtained by using data collected by the first generation ERS-1/2 and ENVISAT systems. A comparison with one ALOS satellite dataset is also included. Most of the results, based on the application of Differential SAR Interferometry (DInSAR) techniques, highlight how this technology is not anymore just a sophisticated tool for remotely studying surface deformation phenomena, but it is becoming an operational system for near-real time deformation monitoring. Moreover, we also show how the improved spatial resolution extends the possibility to exploit SAR image amplitude, instead of phase, for direct comparison with optical data and for imaging large deformation episodes, typically associated with strong seismic events, for which DInSAR may fail.

  17. Alaska SAR Facility (ASF5) SAR Communications (SARCOM) Data Compression System

    NASA Technical Reports Server (NTRS)

    Mango, Stephen A.

    1989-01-01

    The real-time operational requirements for SARCOM translation into a high speed image data handler and processor to achieve the desired compression ratios and the selection of a suitable image data compression technique with as low as possible fidelity (information) losses and which can be implemented in an algorithm placing a relatively low arithmetic load on the system are described.

  18. Clocks for airborne systems. [performance of rubidium oscillators

    NASA Technical Reports Server (NTRS)

    Houlding, N.

    1982-01-01

    The potential performance of compact oscillators, needed for the development of accurate clocks for future airborne systems (such as Identification Friend or Foe schemes), is addressed. In particular, extensive testing of rubidium oscillators manufactured by Efratom is discussed. The results indicate that an accuracy of better than 10 microseconds should be achievable in tactical aircraft provided that appropriate measures are adopted to counter the many environmental factors. In a favorable environment a stability of better than 5 x 10 to the -13th power for one day is achievable with present commercial units, but improvements are required to suit operation in an aircraft. With further development of rubidium controlled clocks the ultimate limitation on time accuracy in aircraft will probably be associated with time dissemination, maintenance difficulties and doctrinal hurdles.

  19. A Scheme of Intelligent Oil Spill Monitoring System by SAR for Operational Application

    NASA Astrophysics Data System (ADS)

    Zeng, Kan; Ma, Youjun; Ding, Xingtao; Zhao, Chaofang; He, Mingxia

    2014-11-01

    A scheme of intelligent oil spill monitoring system by SAR for operational application is presented. The system includes four key techniques. 1) Picking out dark targets from SAR images using a new adaptive threshold segmentation algorithm based on evaluating the trends of background of SAR image along the range direction. The algorithm is applicable for SAR images of different satellites. 2) Filtering out some of look-alikes from dark targets by a chain of rules. 3) Extracting features from all the remained dark targets, selecting the most useful features and then discriminating the targets between oil spill and look-alikes by an artificial neural network (ANN). The feature extraction is based on lots of targets. The ANN experiences enough training. 4) Using an intelligent feedback with expert knowledge and relevant environment parameters to continually optimize system and improve the detection rate. So far, the test on 1448 oil spill and look-alike targets from Envisat/ASAR images shows that the correct recognition rate of the system can reach 88 % without the intelligent feedback.

  20. Dual-Frequency Airborne Scanning Rain Radar Antenna System

    NASA Technical Reports Server (NTRS)

    Hussein, Ziad A.; Green, Ken

    2004-01-01

    A compact, dual-frequency, dual-polarization, wide-angle-scanning antenna system has been developed as part of an airborne instrument for measuring rainfall. This system is an upgraded version of a prior single-frequency airborne rain radar antenna system and was designed to satisfy stringent requirements. One particularly stringent combination of requirements is to generate two dual-polarization (horizontal and vertical polarizations) beams at both frequencies (13.405 and 35.605 GHz) in such a way that the beams radiated from the antenna point in the same direction, have 3-dB angular widths that match within 25 percent, and have low sidelobe levels over a wide scan angle at each polarization-and-frequency combination. In addition, the system is required to exhibit low voltage standing-wave ratios at both frequencies. The system (see figure) includes a flat elliptical scanning reflector and a stationary offset paraboloidal reflector illuminated by a common-aperture feed system that comprises a corrugated horn with four input ports one port for each of the four frequency-and-polarization combinations. The feed horn is designed to simultaneously (1) under-illuminate the reflectors 35.605 GHz and (2) illuminate the reflectors with a 15-dB edge taper at 13.405 GHz. The scanning mirror is rotated in azimuth to scan the antenna beam over an angular range of 20 in the cross-track direction for wide swath coverage, and in elevation to compensate for the motion of the aircraft. The design of common-aperture feed horn makes it possible to obtain the required absolute gain and low side-lobe levels in wide-angle beam scanning. The combination of the common-aperture feed horn with the small (0.3) focal-length-to-diameter ratio of the paraboloidal reflector makes it possible for the overall system to be compact enough that it can be mounted on a DC-8 airplane.

  1. Airborne laser systems for atmospheric sounding in the near infrared

    NASA Astrophysics Data System (ADS)

    Sabatini, Roberto; Richardson, Mark A.; Jia, Huamin; Zammit-Mangion, David

    2012-06-01

    This paper presents new techniques for atmospheric sounding using Near Infrared (NIR) laser sources, direct detection electro-optics and passive infrared imaging systems. These techniques allow a direct determination of atmospheric extinction and, through the adoption of suitable inversion algorithms, the indirect measurement of some important natural and man-made atmospheric constituents, including Carbon Dioxide (CO2). The proposed techniques are suitable for remote sensing missions performed by using aircraft, satellites, Unmanned Aerial Vehicles (UAV), parachute/gliding vehicles, Roving Surface Vehicles (RSV), or Permanent Surface Installations (PSI). The various techniques proposed offer relative advantages in different scenarios. All are based on measurements of the laser energy/power incident on target surfaces of known geometric and reflective characteristics, by means of infrared detectors and/or infrared cameras calibrated for radiance. Experimental results are presented relative to ground and flight trials performed with laser systems operating in the near infrared (NIR) at λ = 1064 nm and λ = 1550 nm. This includes ground tests performed with 10 Hz and 20 KHz PRF NIR laser systems in a variety of atmospheric conditions, and flight trials performed with a 10 Hz airborne NIR laser system installed on a TORNADO aircraft, flying up to altitudes of 22,000 ft above ground level. Future activities are planned to validate the atmospheric retrieval algorithms developed for CO2 column density measurements, with emphasis on aircraft related emissions at airports and other high air-traffic density environments.

  2. Exposure to airborne particulate matter in the subway system.

    PubMed

    Martins, Vânia; Moreno, Teresa; Minguillón, María Cruz; Amato, Fulvio; de Miguel, Eladio; Capdevila, Marta; Querol, Xavier

    2015-04-01

    The Barcelona subway system comprises eight subway lines, at different depths, with different tunnel dimensions, station designs and train frequencies. An extensive measurement campaign was performed in this subway system in order to characterise the airborne particulate matter (PM) measuring its concentration and investigating its variability, both inside trains and on platforms, in two different seasonal periods (warmer and colder), to better understand the main factors controlling it, and therefore the way to improve air quality. The majority of PM in the underground stations is generated within the subway system, due to abrasion and wear of rail tracks, wheels and braking pads caused during the motion of the trains. Substantial variation in average PM concentrations between underground stations was observed, which might be associated to different ventilation and air conditioning systems, characteristics/design of each station and variations in the train frequency. Average PM2.5 concentrations on the platforms in the subway operating hours ranged from 20 to 51 and from 41 to 91 μg m(-3) in the warmer and colder period, respectively, mainly related to the seasonal changes in the subway ventilation systems. The new subway lines with platform screen doors showed PM2.5 concentrations lower than those in the conventional system, which is probably attributable not only to the more advanced ventilation setup, but also to the lower train frequency and the design of the stations. PM concentrations inside the trains were generally lower than those on the platforms, which is attributable to the air conditioning systems operating inside the trains, which are equipped with air filters. This study allows the analysis and quantification of the impact of different ventilation settings on air quality, which provides an improvement on the knowledge for the general understanding and good management of air quality in the subway system.

  3. SARS Basics

    MedlinePlus

    ... coronavirus (SARS-CoV). SARS was first reported in Asia in February 2003. Over the next few months, ... countries in North America, South America, Europe, and Asia before the SARS global outbreak of 2003 was ...

  4. Medium altitude airborne Geiger-mode mapping LIDAR system

    NASA Astrophysics Data System (ADS)

    Clifton, William E.; Steele, Bradley; Nelson, Graham; Truscott, Antony; Itzler, Mark; Entwistle, Mark

    2015-05-01

    Over the past 15 years the Massachusetts Institute of Technology, Lincoln Laboratory (MIT/LL), Defense Advanced Research Projects Agency (DARPA) and private industry have been developing airborne LiDAR systems based on arrays of Geiger-mode Avalanche Photodiode (GmAPD) detectors capable of detecting a single photon. The extreme sensitivity of GmAPD detectors allows operation of LiDAR sensors at unprecedented altitudes and area collection rates in excess of 1,000 km2/hr. Up until now the primary emphasis of this technology has been limited to defense applications despite the significant benefits of applying this technology to non-military uses such as mapping, monitoring critical infrastructure and disaster relief. This paper briefly describes the operation of GmAPDs, design and operation of a Geiger-mode LiDAR, a comparison of Geiger-mode and traditional linear mode LiDARs, and a description of the first commercial Geiger-mode LiDAR system, the IntelliEarth™ Geospatial Solutions Geiger-mode LiDAR sensor.

  5. ERS-1 SAR geocoding system as link between spaceborne and earth reference data

    NASA Astrophysics Data System (ADS)

    Schreier, Gunter; Roth, Achim; Knöpfle, Walter

    1993-08-01

    The operational European ground segment of the European Remote Sensing Satellite ERS-1 supports geocoded SAR image data generated by the German Processing and Archiving Facility (D-PAF) of DLR in Oberpfaffenhofen near Munich. Geocoding of spaceborne satellite data means to establish an easy and user friendly link between the satellite measurements and Geo-Information Systems (GIS) as well as the possibility to intercompare SAR data with other geocoded satellite based information. Although the near to fully automatic geocoding system is based on precisely known satellite house-keeping data, it strongly depends on georeference information at least for the validation of the data and the verification of its results. Such reference information are large scale topographic maps, which are still the unique global source for earth based information and Digital Elevation Models. The later are necessary to correct SAR data for disturbing height induced geometric and radiometric defects. Additionally automatically generated Image Ground Control Chips aid the precision of the system. To accomplish the task of operational geocoding, several consistent data bases have been generated at DLR to store these types of reference data. Both, relational data base techniques as well as spatial binary reference systems are in use for the data storage. The article will present the architecture of these operational systems and will give a first review of the experience with these systems during the ERS-1 commissioning and early operations phase.

  6. Airborne laser ranging system for monitoring regional crustal deformation

    NASA Technical Reports Server (NTRS)

    Degnan, J. J.

    1981-01-01

    Alternate approaches for making the atmospheric correction without benefit of a ground-based meteorological network are discussed. These include (1) a two-color channel that determines the atmospheric correction by measuring the time delay induced by dispersion between pulses at two optical frequencies; (2) single-color range measurements supported by an onboard temperature sounder, pressure altimeter readings, and surface measurements by a few existing meteorological facilities; and (3) inclusion of the quadratic polynomial coefficients as variables to be solved for along with target coordinates in the reduction of the single-color range data. It is anticipated that the initial Airborne Laser Ranging System (ALRS) experiments will be carried out in Southern California in a region bounded by Santa Barbara on the norht and the Mexican border on the south. The target area will be bounded by the Pacific Ocean to the west and will extend eastward for approximately 400 km. The unique ability of the ALRS to provide a geodetic 'snapshot' of such a large area will make it a valuable geophysical tool.

  7. A system-level simulator for indoor mmW SAR imaging and its applications.

    PubMed

    Qi, Feng; Ocket, Ilja; Schreurs, Dominique; Nauwelaers, Bart

    2012-10-08

    Recently, the research interest in indoor active millimeter wave (mmW) imaging by applying the synthetic aperture radar (SAR) technique is increasing. However, there is a lack of proper computer-aided design (CAD) tools at the system level, and almost all the R&D activities rely on experiments solely. The high cost of such a system stops many researchers from investigating such a fascinating research topic. Moreover, the experiment-oriented studies may blind the researchers to some details during the imaging process, since in most cases they are only interested in the readout from the receivers and do not know how the waves perform in reality. To bridge such a gap, we propose a modeling approach at mmW frequencies, which is able to simulate the physical process during SAR imaging. We are not going to discuss about advanced image reconstruction algorithms, since they have already been investigated intensively for decades. To distinguish from previous work, for the first time, we model the data acquisition process in a SAR imaging system successfully at mmW frequencies. We show how to perform some system-level studies based on such a simulator via a common PC, including the influence of reflectivity contrast between object and background, sampling step, and antenna's directivity on image quality. The simulator can serve system design purposes and it can be easily extended to THz frequencies.

  8. Multibeam monopulse radar for airborne sense and avoid system

    NASA Astrophysics Data System (ADS)

    Gorwara, Ashok; Molchanov, Pavlo

    2016-10-01

    The multibeam monopulse radar for Airborne Based Sense and Avoid (ABSAA) system concept is the next step in the development of passive monopulse direction finder proposed by Stephen E. Lipsky in the 80s. In the proposed system the multibeam monopulse radar with an array of directional antennas is positioned on a small aircaraft or Unmanned Aircraft System (UAS). Radar signals are simultaneously transmitted and received by multiple angle shifted directional antennas with overlapping antenna patterns and the entire sky, 360° for both horizontal and vertical coverage. Digitizing of amplitude and phase of signals in separate directional antennas relative to reference signals provides high-accuracy high-resolution range and azimuth measurement and allows to record real time amplitude and phase of reflected from non-cooperative aircraft signals. High resolution range and azimuth measurement provides minimal tracking errors in both position and velocity of non-cooperative aircraft and determined by sampling frequency of the digitizer. High speed sampling with high-accuracy processor clock provides high resolution phase/time domain measurement even for directional antennas with wide Field of View (FOV). Fourier transform (frequency domain processing) of received radar signals provides signatures and dramatically increases probability of detection for non-cooperative aircraft. Steering of transmitting power and integration, correlation period of received reflected signals for separate antennas (directions) allows dramatically decreased ground clutter for low altitude flights. An open architecture, modular construction allows the combination of a radar sensor with Automatic Dependent Surveillance - Broadcast (ADS-B), electro-optic, acoustic sensors.

  9. Software for Generating Strip Maps from SAR Data

    NASA Technical Reports Server (NTRS)

    Hensley, Scott; Michel, Thierry; Madsen, Soren; Chapin, Elaine; Rodriguez, Ernesto

    2004-01-01

    Jurassicprok is a computer program that generates strip-map digital elevation models and other data products from raw data acquired by an airborne synthetic-aperture radar (SAR) system. This software can process data from a variety of airborne SAR systems but is designed especially for the GeoSAR system, which is a dual-frequency (P- and X-band), single-pass interferometric SAR system for measuring elevation both at the bare ground surface and top of the vegetation canopy. Jurassicprok is a modified version of software developed previously for airborne-interferometric- SAR applications. The modifications were made to accommodate P-band interferometric processing, remove approximations that are not generally valid, and reduce processor-induced mapping errors to the centimeter level. Major additions and other improvements over the prior software include the following: a) A new, highly efficient multi-stage-modified wave-domain processing algorithm for accurately motion compensating ultra-wideband data; b) Adaptive regridding algorithms based on estimated noise and actual measured topography to reduce noise while maintaining spatial resolution; c) Exact expressions for height determination from interferogram data; d) Fully calibrated volumetric correlation data based on rigorous removal of geometric and signal-to-noise decorrelation terms; e) Strip range-Doppler image output in user-specified Doppler coordinates; f) An improved phase-unwrapping and absolute-phase-determination algorithm; g) A more flexible user interface with many additional processing options; h) Increased interferogram filtering options; and i) Ability to use disk space instead of random- access memory for some processing steps.

  10. Airborne Asbestos Exposures from Warm Air Heating Systems in Schools.

    PubMed

    Burdett, Garry J; Dewberry, Kirsty; Staff, James

    2016-01-01

    The aim of this study was to investigate the concentrations of airborne asbestos that can be released into classrooms of schools that have amosite-containing asbestos insulation board (AIB) in the ceiling plenum or other spaces, particularly where there is forced recirculation of air as part of a warm air heating system. Air samples were collected in three or more classrooms at each of three schools, two of which were of CLASP (Consortium of Local Authorities Special Programme) system-built design, during periods when the schools were unoccupied. Two conditions were sampled: (i) the start-up and running of the heating systems with no disturbance (the background) and (ii) running of the heating systems during simulated disturbance. The simulated disturbance was designed to exceed the level of disturbance to the AIB that would routinely take place in an occupied classroom. A total of 60 or more direct impacts that vibrated and/or flexed the encapsulated or enclosed AIB materials were applied over the sampling period. The impacts were carried out at the start of the sampling and repeated at hourly intervals but did not break or damage the AIB. The target air volume for background samples was ~3000 l of air using a static sampler sited either below or ~1 m from the heater outlet. This would allow an analytical sensitivity (AS) of 0.0001 fibres per millilitre (f ml(-1)) to be achieved, which is 1000 times lower than the EU and UK workplace control limit of 0.1 f ml(-1). Samples with lower volumes of air were also collected in case of overloading and for the shorter disturbance sampling times used at one site. The sampler filters were analysed by phase contrast microscopy (PCM) to give a rapid determination of the overall concentration of visible fibres (all types) released and/or by analytical transmission electron microscopy (TEM) to determine the concentration of asbestos fibres. Due to the low number of fibres, results were reported in terms of both the calculated

  11. Airborne Asbestos Exposures from Warm Air Heating Systems in Schools

    PubMed Central

    Burdett, Garry J.; Dewberry, Kirsty; Staff, James

    2016-01-01

    The aim of this study was to investigate the concentrations of airborne asbestos that can be released into classrooms of schools that have amosite-containing asbestos insulation board (AIB) in the ceiling plenum or other spaces, particularly where there is forced recirculation of air as part of a warm air heating system. Air samples were collected in three or more classrooms at each of three schools, two of which were of CLASP (Consortium of Local Authorities Special Programme) system-built design, during periods when the schools were unoccupied. Two conditions were sampled: (i) the start-up and running of the heating systems with no disturbance (the background) and (ii) running of the heating systems during simulated disturbance. The simulated disturbance was designed to exceed the level of disturbance to the AIB that would routinely take place in an occupied classroom. A total of 60 or more direct impacts that vibrated and/or flexed the encapsulated or enclosed AIB materials were applied over the sampling period. The impacts were carried out at the start of the sampling and repeated at hourly intervals but did not break or damage the AIB. The target air volume for background samples was ~3000 l of air using a static sampler sited either below or ~1 m from the heater outlet. This would allow an analytical sensitivity (AS) of 0.0001 fibres per millilitre (f ml−1) to be achieved, which is 1000 times lower than the EU and UK workplace control limit of 0.1 f ml−1. Samples with lower volumes of air were also collected in case of overloading and for the shorter disturbance sampling times used at one site. The sampler filters were analysed by phase contrast microscopy (PCM) to give a rapid determination of the overall concentration of visible fibres (all types) released and/or by analytical transmission electron microscopy (TEM) to determine the concentration of asbestos fibres. Due to the low number of fibres, results were reported in terms of both the calculated

  12. Rapid System to Quantitatively Characterize the Airborne Microbial Community

    NASA Technical Reports Server (NTRS)

    Macnaughton, Sarah J.

    1998-01-01

    Bioaerosols have been linked to a wide range of different allergies and respiratory illnesses. Currently, microorganism culture is the most commonly used method for exposure assessment. Such culture techniques, however, generally fail to detect between 90-99% of the actual viable biomass. Consequently, an unbiased technique for detecting airborne microorganisms is essential. In this Phase II proposal, a portable air sampling device his been developed for the collection of airborne microbial biomass from indoor (and outdoor) environments. Methods were evaluated for extracting and identifying lipids that provide information on indoor air microbial biomass, and automation of these procedures was investigated. Also, techniques to automate the extraction of DNA were explored.

  13. Examination of Airborne FDEM System Attributes for UXO Mapping and Detection

    DTIC Science & Technology

    2009-11-01

    process, or service by trade name, trademark, manufacturer , or otherwise, does not necessarily constitute or imply its endorsement, recommendation...the semi-airborne configuration. We propose to extend the current SAIC codes to address this need, and to perform additional modeling using codes...transmitter with the existing receivers on the TEM-8 system. Additional airborne measurements will be made with Cases 2 and 4 receiver

  14. An Introduction to Coastal Zone Mapping With Airborne Lidar: The Shoals System

    DTIC Science & Technology

    2000-01-01

    AN INTRODUCTION TO COASTAL ZONE MAPPING WITH AIRBORNE LIDAR : THE SHOALS SYSTEM Jennifer L. Irish US Army Engineer Research and Development...Center Coastal and Hydraulics Laboratory Joint Airborne Lidar Bathymetry Technical Center of Expertise 109 St. Joseph Street, Mobile, AL 36602-3630...USA http://shoals.sam.usace.army.mil ABSTRACT Recent advancements in lidar sensors now allow for near-synoptic, regional-scale mapping of the

  15. A Portable Airborne Scanning Lidar System for Ocean and Coastal Applications

    DTIC Science & Technology

    2009-06-26

    has been quantified in many studies with several different airborne lidar systems. Robertson et al. (2007) measured beach erosion caused by Hurricane...Mech., 156, 505–531. Robertson , W., K. Zhang, and D. Whitman, 2007: Hurricane- induced beach change derived from airborne laser mea- surements near...level changes on Southern California beaches. Ph.D. thesis, University of California, San Diego, 155 pp. ——, R. Guza, R. Gutierrez, and R. Seymour

  16. Urban area mapping from polarimetric SAR data using fuzzy inference system

    NASA Astrophysics Data System (ADS)

    Ahluwalia, Asmeet; Manickam, Surendar; Bhattacharya, Avik; Porwal, Alok

    2016-05-01

    In this work, we present urban area mapping from full-polarimetric synthetic aperture radar (SAR) data using fuzzy inference system (FIS). In particular, our aim is to utilize the profound knowledge available about scattering mechanism from urban targets to delineate urban environment. In this approach, we have utilized the recently developed polarimetric SAR scattering power decomposition technique (SD-Y4O) given in Bhattacharya et. al. The improved powers along with some other polarimetric parameters were used in this study. A suitable normalization procedure was adapted to handle the skewness in the estimated parameters. The fuzzy if-then rules were constructed from the in-depth knowledge of scattering mechanisms from an urban environment. Suitable methods were introduced to define the fuzzy inference system. The defuzzified membership values were thresholded using an unsupervised clustering method (k-means). The pixels lying in the range [μmax-σ, μmax+σ] corresponds to urban areas where µmax is the largest cluster center and σ is the standard deviation of the cluster corresponding to µmax. The extracted urban area is in visually good agreement with the high resolution optical image. ALOS PALSAR full-polarimetric L-band SAR data has been used in this study.

  17. Chirp Scaling Algorithms for SAR Processing

    NASA Technical Reports Server (NTRS)

    Jin, M.; Cheng, T.; Chen, M.

    1993-01-01

    The chirp scaling SAR processing algorithm is both accurate and efficient. Successful implementation requires proper selection of the interval of output samples, which is a function of the chirp interval, signal sampling rate, and signal bandwidth. Analysis indicates that for both airborne and spaceborne SAR applications in the slant range domain a linear chirp scaling is sufficient. To perform nonlinear interpolation process such as to output ground range SAR images, one can use a nonlinear chirp scaling interpolator presented in this paper.

  18. Signal subspace change detection in averaged multi-look SAR imagery

    NASA Astrophysics Data System (ADS)

    Ranney, Kenneth; Soumekh, Mehrdad

    2005-05-01

    Modern Synthetic Aperture Radar (SAR) signal processing algorithms could retrieve accurate and subtle information regarding a scene that is being interrogated by an airborne radar system. An important reconnaissance problem that is being studied via the use of SAR systems and their sophisticated signal processing methods involves detecting changes in an imaged scene. In these problems, the user interrogates a scene with a SAR system at two different time points (e.g. different days); the resultant two SAR databases that we refer to as reference and test data, are used to determine where targets have entered or left the imaged scene between the two data acquisitions. For instance, X band SAR systems have the potential to become a potent tool to determine whether mines have been recently placed in an area. This paper describes an algorithm for detecting changes in averaged multi-look SAR imagery. Averaged multi-look SAR images are preferable to full aperture SAR reconstructions when the imaging algorithm is approximation based (e.g. polar format processing), or motion data are not accurate over a long full aperture. We study the application of a SAR detection method, known as Signal Subspace Processing, that is based on the principles of 2D adaptive filtering. We identify the change detection problem as a binary hypothesis-testing problem, and identify an error signal and its normalized version to determine whether i) there is no change in the imaged scene; or ii) a target has been added to the imaged scene. A statistical analysis of the error signal is provided to show its properties and merits. Results are provided for data collected by an X band SAR platform and processed to form non-coherently look-averaged SAR images.

  19. Geologic mapping in Death Valley, California/Nevada using NASA/JPL airborne systems (AVIRIS, TIMS, and AIRSAR)

    NASA Technical Reports Server (NTRS)

    Kruse, Fred A.; Dietz, John B.; Kiereinyoung, Kathryn S.

    1991-01-01

    A multi-sensor aircraft campaign called the Geologic Remote Sensing Field Experiment (GRSFE) conducted during 1989 resulted in acquisition of high quality multispectral images in the visible, near infrared, shortwave infrared, thermal infrared, and microwave regions of the electromagnetic spectrum. The airborne data sets include the Airborne Visible/Infrared Imaging Spectrometer (AVIRIS), the Thermal Infrared Multispectral Scanner (TIMS), and the Airborne Synthetic Aperture Radar (SAR). Ancillary data include Landsat Thematic Mapper, laboratory and field spectral measurements, and traditional geologic mapping. The GRSFE data for a site in the northern Death Valley, (California and Nevada) region were calibrated to physical units and geometrically registered to a map base. Various aspects of this experiment are briefly discussed.

  20. Nyamulagira’s magma plumbing system inferred from 15 years of InSAR

    USGS Publications Warehouse

    Wauthier, Christelle; Cayol, Valérie; Poland, Michael; Kervyn, François; D'Oreye, Nicolas; Hooper, Andrew; Samsonov, Sergei; Tiampo, Kristy; Smets, Benoit; Pyle, D. M.; Mather, T.A.; Biggs, J.

    2013-01-01

    Nyamulagira, located in the east of the Democratic Republic of Congo on the western branch of the East African rift, is Africa’s most active volcano, with an average of one eruption every 3 years since 1938. Owing to the socio-economical context of that region, the volcano lacks ground-based geodetic measurements but has been monitored by interferometric synthetic aperture radar (InSAR) since 1996. A combination of 3D Mixed Boundary Element Method and inverse modelling, taking into account topography and source interactions, is used to interpret InSAR ground displacements associated with eruptive activity in 1996, 2002, 2004, 2006 and 2010. These eruptions can be fitted by models incorporating dyke intrusions, and some (namely the 2006 and 2010 eruptions) require a magma reservoir beneath the summit caldera. We investigate inter-eruptive deformation with a multi-temporal InSAR approach. We propose the following magma plumbing system at Nyamulagira by integrating numerical deformation models with other available data: a deep reservoir (c. 25 km depth) feeds a shallower reservoir (c. 4 km depth); proximal eruptions are fed from the shallow reservoir through dykes while distal eruptions can be fed directly from the deep reservoir. A dyke-like conduit is also present beneath the upper southeastern flank of Nyamulagira.

  1. Design and performance simulations for an airborne DIAL system for long-range remote sensing applications

    NASA Astrophysics Data System (ADS)

    Dowling, James A.; Kelly, Brian T.; Gonglewski, John D.; Fox, Marsha J.; Shilko, Michael L.; Higdon, Noah S.; Highland, Ronald G.; Senft, Daniel C.; Dean, David R.; Blackburn, John P.; Pierrottet, Diego F.

    1997-01-01

    The U.S. Air Force Phillips Laboratory is evaluating the feasibility of long-standoff-range remote sensing of gaseous species present in trace amounts in the atmosphere. To date, the Phillips Laboratory program has been concerned with the preliminary design and performance analysis of a commercially available CO(subscript 2) laser-based DIAL system operating from mountain-top-observatory and airborne platform and more recently with long-range ground testing using a 21.8 km slant path from 3.05 km ASL to sea level as the initial steps in the design and development of an airborne system capability. Straightforward scaling of the performance of a near-term technology direct-detection LIDAR system with propagation range to a topographic target and with the average atmospheric absorption coefficient along the path has been performed. Results indicate that useful airborne operation of such a system should be possible for slant path ranges between 20 km and 50 km, depending upon atmospheric transmission at the operating wavelengths of the (superscript 13)C(superscript 16)O(subscript 2) source. This paper describes the design of the airborne system which will be deployed on the Phillips Laboratory NC-135 research aircraft for DIAL system performance tests at slant ranges of 20 km to 50 km, scheduled for the near future. Performance simulations for the airborne tests will be presented and related to performance obtained during initial ground-based tests.

  2. Airborne spectrograph for the thermal IR: Broadband Array Spectrograph System

    NASA Astrophysics Data System (ADS)

    Russell, Ray W.; Hackwell, John; Lynch, David; Mazuk, Ann

    Spectroscopic studies in the 'fingerprint' region of the thermal IR from 3 to 14 microns of celestial dust components and the overall energy distribution of the sources are best served by moderate spectral resolution (R = lambda/Delta lambda approximately 30 to 200), high sensitivity observations. Spectral purity and the reproducibility of the spectral shape are critical as well, when using the spectral shape to assign temperatures to dust grains or to gas clouds based on the wavelength and shape of molecular bands. These sensor attributes are also important to the use of wavelengths and ratios of solid state features to derive compositions of dust grains in celestial sources. The advent of high quality linear arrays of blocked impurity band (BIB) detectors of Si:As permitted the development of a state-of-the-art, patented, cooled prism spectrograph. Developed at The Aerospace Corporation largely with in-house funds, the Broadband Array Spectrograph System (BASS) has been used for a variety of remote sensing applications, but especially for IR astronomical studies on the Kuiper Airborne Observatory and at the NASA Infrared Telescope Facility (IRTF). The attributes of the spectrograph, specifically having the pupil imaged onto the 2 linear 58 element detector arrays so that the effects of guiding errors are minimized, being able to maximally exploit the limited observing time by acquiring all 116 spectral channels simultaneously, and having all spectral channels imaged through the same aperture so that spectral mapping is readily and reliably accomplished, afford the scientist with a unique opportunity to conduct both surveys of examples of many different types of sources as well as in-depth studies of a given class of object by thoroughly sampling the class members. This duality was demonstrated with the BASS through a combination of KAO flights where spectral maps were obtained as part of in-depth studies of specific source regions (such as Orion and W3) and

  3. Processing pharus data with the generic SAR processor

    SciTech Connect

    Otten, M.P.G.

    1996-11-01

    The Generic SAR Processor (GSP) is a SAR processing environment created to process airborne and spaceborne SAR data with a maximum amount of flexibility, while at the same time providing a user friendly and powerful environment for handling and analyzing SAR, including polarimetric calibration. PHARUS is an airborne polarimetric C-band SAR, utilizing an active (solid state) phased array. The absence of mechanical antenna stabilization, the use of electronic beam steering, in combination with high PRF, polarimetric operation, under motion condition which can be severe, requires a very large flexibility of the SAR processor. The GSP is designed to handle this type of SAR data with a very flexible motion compensation-, azimuth compression-, and radiometric correction approach. First experiences with the processing of PHARUS data show that this is a valid approach to obtain high quality polarimetric imagery with a phased array SAR. 4 refs., 5 figs.

  4. Development and testing of a long-range airborne CO2 DIAL chemical detection system

    NASA Astrophysics Data System (ADS)

    Higdon, N. Scott; Senft, Daniel C.; Fox, Marsha J.; Hamilton, Carla M.; Kelly, Brian T.; Dowling, James A.; Pierrottet, Diego F.; Dean, David R.; Richter, Dale A.; Bousek, Ronald R.

    1998-11-01

    The Air Force Research Laboratory has developed and tested an airborne CO2 differential absorption lidar system for the remote detection of chemicals. The Laser Airborne Remote Sensing DIAL system uses topographic backscatter to provide a long-range measurement of the column-content absorption of chemical plumes in the path of the laser beam. A high-power CO2 laser, capable of operation on multiple isotopes, and a Mersenne telescope constitute the major transceiver components. In addition to the laser, telescope, and transceiver optics, several onboard diagnostic instruments were mounted on the flight bench to monitor and optimize the system performance during airborne operation. The flight bench, electronics racks, and data acquisition and experiment control stations were designed to be integrated onto the AFRL C-135E research aircraft, and to utilize the existing pointing and tracking system on the aircraft.

  5. UWB SAR system PULSAR: new generator and antenna developments

    NASA Astrophysics Data System (ADS)

    Delmonte, Philippe; Dubois, Cyril; Andrieu, Jo"l.; Beillard, Bruno; Lalande, Michèle; Bertrand, Valérie; Jecko, Bernard; Pecastaing, Laurent; Gibert, Alain; Paillol, Jean; Domens, Pierre; Guillerey, Régis; Monnier, Francis; Legoff, Marc

    2003-08-01

    PULSAR is an Ultra Wide-Band short pulse Radar developed by the CELAR (French Technical Centre for Armament Electronics) and the IRCOM (Research Institute of Microwave and Optical Communications) in order to detect foliage and ground concealed targets. One of the most promising mission of such potential radar is the detection of buried and surface land mine fields. An instrumentation measurement system has been designed and implemented. This paper deals with the recent development efforts on this system, specially on a new pulse generator and a new UWB antenna. Recently, the LGE (Laboratoire de Génie Electrique) has developed a high voltage pulse coaxial generator. These recent developments allowed to increase the pulse output voltage and the pulse rise time. The new UWB antenna is able to support a very high voltage; the bandwidth and the gain are greater than the ones of the previous antenna.

  6. 76 FR 50808 - Airborne Supplemental Navigation Equipment Using the Global Positioning System (GPS)

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-08-16

    ... standard for GPS sensors not augmented by satellite-based or ground- based systems (i.e., TSO-C129a Class B and Class C). The FAA has also published two GPS TSOs augmented by the satellite-based augmentation system (TSO-C145c, Airborne Navigation Sensors Using the Global Positioning System Augmented by...

  7. Airborne sensor systems under development at the NASA/NSTL/Earth Resources Laboratory

    NASA Technical Reports Server (NTRS)

    Anderson, James E.; Meeks, Gerald R.

    1988-01-01

    The operational characteristics of the Airborne Bathymetric System (ABS) MSS and the Airborne Multispectral Pushbroom Scanner (AMPS), which are currently being developed at NASA's Earth Resources Laboratory (ERL), are described. The ABS MSS system scans through a swath width of + or - 40 deg from nadir and the sensor incorporates onboard calibration references for the visible and short-wavelength IR channels. The AMPS uses five separate f/1.8 refractive telecentric lens systems, each incorporating nine optical elements, and a replaceable fixed bandwidth filter.

  8. Development of a Cost-Effective Airborne Remote Sensing System for Coastal Monitoring

    PubMed Central

    Kim, Duk-jin; Jung, Jungkyo; Kang, Ki-mook; Kim, Seung Hee; Xu, Zhen; Hensley, Scott; Swan, Aaron; Duersch, Michael

    2015-01-01

    Coastal lands and nearshore marine areas are productive and rapidly changing places. However, these areas face many environmental challenges related to climate change and human-induced impacts. Space-borne remote sensing systems may be restricted in monitoring these areas because of their spatial and temporal resolutions. In situ measurements are also constrained from accessing the area and obtaining wide-coverage data. In these respects, airborne remote sensing sensors could be the most appropriate tools for monitoring these coastal areas. In this study, a cost-effective airborne remote sensing system with synthetic aperture radar and thermal infrared sensors was implemented to survey coastal areas. Calibration techniques and geophysical model algorithms were developed for the airborne system to observe the topography of intertidal flats, coastal sea surface current, sea surface temperature, and submarine groundwater discharge. PMID:26437413

  9. Development of a Cost-Effective Airborne Remote Sensing System for Coastal Monitoring.

    PubMed

    Kim, Duk-jin; Jung, Jungkyo; Kang, Ki-mook; Kim, Seung Hee; Xu, Zhen; Hensley, Scott; Swan, Aaron; Duersch, Michael

    2015-09-30

    Coastal lands and nearshore marine areas are productive and rapidly changing places. However, these areas face many environmental challenges related to climate change and human-induced impacts. Space-borne remote sensing systems may be restricted in monitoring these areas because of their spatial and temporal resolutions. In situ measurements are also constrained from accessing the area and obtaining wide-coverage data. In these respects, airborne remote sensing sensors could be the most appropriate tools for monitoring these coastal areas. In this study, a cost-effective airborne remote sensing system with synthetic aperture radar and thermal infrared sensors was implemented to survey coastal areas. Calibration techniques and geophysical model algorithms were developed for the airborne system to observe the topography of intertidal flats, coastal sea surface current, sea surface temperature, and submarine groundwater discharge.

  10. 3D Rendering of High Resolution PolInSAR Urban Area

    NASA Astrophysics Data System (ADS)

    Trouve, Nicolas; Colin-Koeniguer, Elise; Cantalloube, Hubert

    2011-03-01

    In the field of urban SAR imaging and mapping, the PolInSAR information potential has not been fully exploited. Until recently available resolution of PolInSAR images were not sufficient to render 3D city landscape using the polarimetric and interferometric information. This paper presents the results of urban reconstruction using single pass full polarimetric and interferometric data using ONERA's Airborne system: RAMSES. It focus on the statistical process designed for the PolInSAR matrices estimation in high resolution urban areas. A region growing algorithm is proposed to design statistically homogeneous region while preserving spatial features of the scene through shape constraints. A companion paper [CKT11] will present the interferometry tools developed to exploit the region growth results. Validation on real data using RAMSES images at X band over Toulouse are presented through 3D colored render results.

  11. Michigan experimental multispectral mapping system: A description of the M7 airborne sensor and its performance

    NASA Technical Reports Server (NTRS)

    Hasell, P. G., Jr.

    1974-01-01

    The development and characteristics of a multispectral band scanner for an airborne mapping system are discussed. The sensor operates in the ultraviolet, visual, and infrared frequencies. Any twelve of the bands may be selected for simultaneous, optically registered recording on a 14-track analog tape recorder. Multispectral imagery recorded on magnetic tape in the aircraft can be laboratory reproduced on film strips for visual analysis or optionally machine processed in analog and/or digital computers before display. The airborne system performance is analyzed.

  12. DoD Weapon Systems Software Management Study. Appendix C. Airborne Systems

    DTIC Science & Technology

    1975-06-01

    s J 2 GOVT ACCESSION NO Subiuiei—I.I..II iPOD WEAPON ffifSTEMS SOFTWARE J^NAGEMENT STÜI« ’APPENDIX C„ AIRBORNE SYSTEMS , 1 ■/]/Special...listings were used as references during the production software development. ( MP3 ) Since system test programs actually comprise three to four times as...program. ( MP3 ) Based on the experience of the P-3C software development, the digital program developers indicate the need for a more structured pro

  13. Airborne Wind Shear Detection and Warning Systems: Third Combined Manufacturers' and Technologists' Conference, part 1

    NASA Technical Reports Server (NTRS)

    Vicroy, Dan D. (Compiler); Bowles, Roland L. (Compiler); Schlickenmaier, Herbert (Compiler)

    1991-01-01

    Papers presented at the conference on airborne wind shear detection and warning systems are compiled. The following subject areas are covered: terms of reference; case study; flight management; sensor fusion and flight evaluation; Terminal Doppler Weather Radar data link/display; heavy rain aerodynamics; and second generation reactive systems.

  14. A high-resolution airborne four-camera imaging system for agricultural remote sensing

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This paper describes the design and testing of an airborne multispectral digital imaging system for remote sensing applications. The system consists of four high resolution charge coupled device (CCD) digital cameras and a ruggedized PC equipped with a frame grabber and image acquisition software. T...

  15. Environmental Protection Agency (EPA) airborne gamma spectrometry system for environmental and emergency response surveys

    NASA Astrophysics Data System (ADS)

    Cardarelli, John, II; Thomas, Mark; Curry, Timothy

    2010-08-01

    The EPA Airborne Spectral Photometric Environmental Collection Technology (ASPECT) Program provides airborne ortho-rectified imagery, video, chemical and now radiological information directly to emergency response personnel via a commercial satellite link onboard the aircraft. EPA initiated the ASPECT Gamma Emergency Mapper GEM Project in 2008 to improve its airborne gamma-screening and mapping capability for monitoring any ground-based gamma contamination. This paper will provide an overview of the system, which can be configured to carry six 2"x4"x16" NaI(Tl) detectors and two 3"x3" LaBr3(Ce) detectors or eight 2"x4"x16" NaI(Tl) detectors. The paper will provide an overview of the analysis of gamma radiation spectra, system limitations, and emergency response applications.

  16. A comparison of the performance of two types of inertial systems for strapdown airborne gravimetry

    NASA Astrophysics Data System (ADS)

    Deurloo, R. A.; Martin, J.; Bastos, M. L.; Becker, M. H.

    2012-12-01

    Over the past two decades so-called strapdown airborne gravimetry systems have proven to have the potential to compete with more traditional measurement systems such as modified spring gravimeters (e.g. LaCoste & Romberg Air-Sea gravimeters). Strapdown gravimetry systems rely on the integration of high-accuracy data from a GNSS (Global Navigation Satellite System) receiver and from a strapdown IMU (Inertial Measurement Unit). These GNSS/IMU integrated systems have the advantage of being less expensive and more compact, while being easier to use and install than spring gravimeters, which tend to be bulky and require specialized human resources for its operation. In the scope of a research project developed through the collaboration of the University of Porto and the Portuguese Air Force (PAF), an airborne survey was recently performed over the middle and southern area of Continental Portugal using a CASA C212 aircraft. The goal of this survey was to acquire data to assess the performance of different GNSS/IMU systems and associated processing approaches to determine the gravity field and evaluate their potential and effectiveness for airborne gravimetry using different types of airborne platforms, including UAVs (Unmanned Airborne Vehicles). Among the systems on board were a medium-quality (tactical grade) IMU with fiber-optic gyros (FOG), a Litton LN-200, and a high-quality (navigation grade) IMU with ring-laser gyros (RLG), an iMAR RHQ-1003, which are the focus of the present comparison. The advantage of using a strapdown airborne gravimetry system with high-quality inertial sensor is that it allows the complete gravity vector to be determined from the triads of accelerometers and gyros in the IMU (vector gravimetry). On the other hand a medium-quality inertial system is limited to determining only the magnitude of the gravity vector (scalar gravimetry). The limited quality of the gyros of the medium-quality inertial systems does not allow the horizontal

  17. Active alignment and vibration control system for a large airborne optical system

    NASA Astrophysics Data System (ADS)

    Kienholz, David A.

    2000-04-01

    Airborne optical or electro-optical systems may be too large for all elements to be mounted on a single integrating structure, other than the aircraft fuselage itself. An active system must then be used to maintain the required alignment between elements. However the various smaller integrating structures (benches) must still be isolated from high- frequency airframe disturbances that could excite resonances outside the bandwidth of the alignment control system. The combined active alignment and vibration isolation functions must be performed by flight-weight components, which may have to operate in vacuum. A testbed system developed for the Air Force Airborne Laser program is described. The payload, a full-scale 1650-lb simulated bench, is mounted in six degrees- of-freedom to a vibrating platform by a set of isolator- actuators. The mounts utilize a combination of pneumatics and magnetics to perform the dual functions of low-frequency alignment and high-frequency isolation. Test results are given and future directions for development are described.

  18. Evaluation of air-liquid interface exposure systems for in vitro assessment of airborne pollutants

    EPA Science Inventory

    Exposure of cells to airborne pollutants at the air-liquid interface (ALI) is a more realistic approach than exposures of submerged cells. The published literature, however, describes irreproducible and/or unrealistic experimental conditions using ALI systems. We have compared fi...

  19. An airborne multispectral imaging system based on two consumer-grade cameras for agricultural remote sensing

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This paper describes the design and evaluation of an airborne multispectral imaging system based on two identical consumer-grade cameras for agricultural remote sensing. The cameras are equipped with a full-frame complementary metal oxide semiconductor (CMOS) sensor with 5616 × 3744 pixels. One came...

  20. A post-processing system for automated rectification and registration of spaceborne SAR imagery

    NASA Technical Reports Server (NTRS)

    Curlander, John C.; Kwok, Ronald; Pang, Shirley S.

    1987-01-01

    An automated post-processing system has been developed that interfaces with the raw image output of the operational digital SAR correlator. This system is designed for optimal efficiency by using advanced signal processing hardware and an algorithm that requires no operator interaction, such as the determination of ground control points. The standard output is a geocoded image product (i.e. resampled to a specified map projection). The system is capable of producing multiframe mosaics for large-scale mapping by combining images in both the along-track direction and adjacent cross-track swaths from ascending and descending passes over the same target area. The output products have absolute location uncertainty of less than 50 m and relative distortion (scale factor and skew) of less than 0.1 per cent relative to local variations from the assumed geoid.

  1. Decentralized adaptive sliding mode control for beam synchronization of tethered InSAR system

    NASA Astrophysics Data System (ADS)

    Zhang, Jinxiu; Zhang, Zhigang; Wu, Baolin

    2016-10-01

    Beam synchronization problem of tethered interferometric synthetic aperture radar (InSAR) is addressed in this paper. Two antennas of the system are carried by separate satellites connected through a tether to obtain a preferable baseline. A Total Zero Doppler Steering (TZDS) is implemented to mother-satellite to cancel the residual Doppler. Subsequently attitude reference trajectories for the two satellites are generated to achieve the beam synchronization and TZDS. Thereafter, a decentralized adaptive sliding mode control law is proposed to track these reference trajectories in the presence of model uncertainties and external disturbances. Finally, the stability of closed-loop system is proved by the corollary of Barbalat's Lemma. Simulation results show the proposed control law is effective to achieve beam synchronization of the system.

  2. Simple SAR demonstrator

    NASA Astrophysics Data System (ADS)

    Kulpa, Krzysztof; Misiurewicz, Jacek; Baranowski, Piotr; Wojdołowicz, Grzegorz

    2008-01-01

    In this paper we present a simple SAR radar demonstrator build using commercially available (COTS) components. For the microwave analog front end, a standard police radar microwave head has been used. The Motorola DSP processor board, equipped with ADC and DAC, has been used for generating of modulating signal and for signal acquisition. The raw radar signal (I and Q components) have been recorded on 2.5" HDD. The signal processing has been performed on standard PC computer after copying the recorded data. The aim of constructing simple and relatively cheap demonstrator was to provide the students the real-life unclassified radar signals and motivate them to test and develop various kinds of SAR and ISAR algorithms, including image formation, motion compensation and autofocusing. The simple microwave frontend hardware has a lot of non-idealities, so for obtaining nice SAR image it was necessary to develop the number of correction algorithms at the calibration stage. The SAR demonstrator have been tested using car as a moving platform. The flight tests with a small airborne platform are planned for the summer.

  3. X-SAR: The X-band synthetic aperture radar on board the Space Shuttle

    NASA Technical Reports Server (NTRS)

    Werner, Marian U.

    1993-01-01

    The X-band synthetic aperture radar (X-SAR) is the German/Italian contribution to the NASA/JPL Shuttle Radar Lab missions as part of the preparation for the Earth Observation System (EOS) program. The Shuttle Radar Lab is a combination of several radars: an L-band (1.2 GHz) and a C-band (5.3 GHz) multipolarization SAR known as SIR-C (Shuttle Imaging Radar); and an X-band (9.6 GHz) vertically polarized SAR which will be operated synchronously over the same target areas to deliver calibrated multifrequency and multipolarization SAR data at multiple incidence angles from space. A joint German/Italian project office at DARA (German Space Agency) is responsible for the management of the X-SAR project. The space hardware has been developed and manufactured under industrial contract by Dornier and Alenia Spazio. Besides supporting all the technical and scientific tasks, DLR, in cooperation with ASI (Agencia Spaziale Italiano) is responsible for mission operation, calibration, and high precision SAR processing. In addition, DLR developed an airborne X-band SAR to support the experimenters with campaigns to prepare for the missions. The main advantage of adding a shorter wavelength (3 cm) radar to the SIR-C radars is the X-band radar's weaker penetration into vegetation and soil and its high sensitivity to surface roughness and associated phenomena. The performance of each of the three radars is comparable with respect to radiometric and geometric resolution.

  4. X-SAR: The X-band synthetic aperture radar on board the Space Shuttle

    NASA Astrophysics Data System (ADS)

    Werner, Marian U.

    1993-05-01

    The X-band synthetic aperture radar (X-SAR) is the German/Italian contribution to the NASA/JPL Shuttle Radar Lab missions as part of the preparation for the Earth Observation System (EOS) program. The Shuttle Radar Lab is a combination of several radars: an L-band (1.2 GHz) and a C-band (5.3 GHz) multipolarization SAR known as SIR-C (Shuttle Imaging Radar); and an X-band (9.6 GHz) vertically polarized SAR which will be operated synchronously over the same target areas to deliver calibrated multifrequency and multipolarization SAR data at multiple incidence angles from space. A joint German/Italian project office at DARA (German Space Agency) is responsible for the management of the X-SAR project. The space hardware has been developed and manufactured under industrial contract by Dornier and Alenia Spazio. Besides supporting all the technical and scientific tasks, DLR, in cooperation with ASI (Agencia Spaziale Italiano) is responsible for mission operation, calibration, and high precision SAR processing. In addition, DLR developed an airborne X-band SAR to support the experimenters with campaigns to prepare for the missions. The main advantage of adding a shorter wavelength (3 cm) radar to the SIR-C radars is the X-band radar's weaker penetration into vegetation and soil and its high sensitivity to surface roughness and associated phenomena. The performance of each of the three radars is comparable with respect to radiometric and geometric resolution.

  5. Synthetic Aperture Radar (SAR) data processing

    NASA Technical Reports Server (NTRS)

    Beckner, F. L.; Ahr, H. A.; Ausherman, D. A.; Cutrona, L. J.; Francisco, S.; Harrison, R. E.; Heuser, J. S.; Jordan, R. L.; Justus, J.; Manning, B.

    1978-01-01

    The available and optimal methods for generating SAR imagery for NASA applications were identified. The SAR image quality and data processing requirements associated with these applications were studied. Mathematical operations and algorithms required to process sensor data into SAR imagery were defined. The architecture of SAR image formation processors was discussed, and technology necessary to implement the SAR data processors used in both general purpose and dedicated imaging systems was addressed.

  6. Mapping Farming Practices in Belgian Intensive Cropping Systems from Sentinel-1 SAR Time Series

    NASA Astrophysics Data System (ADS)

    Chome, G.; Baret, P. V.; Defourny, P.

    2016-08-01

    The environmental impact of the so-called conventional farming system calls for new farming practices reducing negative externalities. Emerging farming practices such as no-till and new inter-cropping management are promising tracks. The development of methods to characterize crop management across an entire region and to understand their spatial dimension offers opportunities to accompany the transition towards a more sustainable agriculture.This research takes advantage of the unmatched polarimetric and temporal resolutions of Sentinel-1 SAR C- band to develop a method to identify farming practices at the parcel level. To this end, the detection of changes in backscattering due to surface roughness modification (tillage, inter-crop cover destruction ...) is used to detect the farming management. The final results are compared to a reference dataset collected through an intensive field campaign. Finally, the performances are discussed in the perspective of practices monitoring of cropping systems through remote sensing.

  7. The development of airborne video system for monitoring of river environments

    SciTech Connect

    Yoshikawa, Shigeya; Mizutani, Nobuyuki; Mizukami, Masumi; Koyano, Toshirou

    1996-11-01

    Recently, airborne videography is widely used by many monitoring for environmental resources, such as rivers, forests, ocean, and so on. Although airborne videography has a low resolution than aerial photographs, it can effectively reduce the cost of continuous monitoring of wide area. Furthermore video images can easily be processed with personal computer. This paper introduces an airborne video system for monitoring of Class A river environment. This system consists of two sub-systems. One is the data collection system that is composed of a video camera, a Global Positioning System(GPS) and a personal computer. This sub-system records information of rivers by video images and their corresponding location data. A GPS system is used for calculating location data and navigating the airplane to the destination of monitoring site. Other is a simplified digital video editing system. This system runs on a personal computer with Microsoft Windows 3.1. This system can also be used for management and planning of road environment, marine resources, forest resources and for prevention of disasters. 7 refs., 4 figs.

  8. Multi-Agent System for Mission and Situational Awareness Management (MASAM) for Airborne Platforms

    DTIC Science & Technology

    2003-01-01

    UNCLASSIFIED MULTI - AGENT SYSTEM FOR MISSION AND SITUATIONAL AWARENESS MANAGEMENT (MASAM) FOR AIRBORNE PLATFORMS (U) John C. Sciortino, Jr...TYPE 3. DATES COVERED 00-00-2003 to 00-00-2003 4. TITLE AND SUBTITLE Multi - Agent System for Mission and Situational Awareness Management (MASAM...Parameters Platform Figure 3: (U) Multi - Agent System for Mission and Situational Awareness Management (Left Panel). Use of CoABS Grid (Right Panel

  9. Thermal management of closed computer modules utilizing high density circuitry. [in Airborne Information Management System

    NASA Technical Reports Server (NTRS)

    Hoadley, A. W.; Porter, A. J.

    1990-01-01

    This paper presents data on a preliminary analysis of the thermal dynamic characteristics of the Airborne Information Management System (AIMS), which is a continuing design project at NASA Dryden. The analysis established the methods which will be applied to the actual AIMS boards as they become available. The paper also describes the AIMS liquid cooling system design and presents a thermodynamic computer model of the AIMS cooling system, together with an experimental validation of this model.

  10. Accurate 2D/3D electromagnetic modeling for time-domain airborne EM systems

    NASA Astrophysics Data System (ADS)

    Yin, C.; Hodges, G.

    2012-12-01

    The existing industry software cannot deliver correct results for 3D time-domain airborne EM responses. In this paper, starting from the Fourier transform and convolution, we compare the stability of different modeling techniques and analyze the reason for instable calculations of the time-domain airborne EM responses. We find that the singularity of the impulse responses of EM systems at very early time that are used in the convolution is responsible for the instability of the modeling (Fig.1). Based on this finding, we put forward an algorithm that uses step response rather than impulse response of the airborne EM system for the convolution and create a stable algorithm that delivers precise results and maintains well the integral/derivative relationship between the magnetic field B and the magnetic induction dB/dt. A three-step transformation procedure for the modeling is proposed: 1) output the frequency-domain EM response data from the existing software; 2) transform into step-response by digital Fourier/Hankel transform; 3) convolve the step response with the transmitting current or its derivatives. The method has proved to be working very well (Fig. 2). The algorithm can be extended to the modeling of other time-domain ground and airborne EM system responses.Fig. 1: Comparison of impulse and step responses for an airborne EM system Fig. 2: Bz and dBz/dt calculated from step (middle panel) and impulse responses (lower panel) for the same 3D model as in Fig.1.

  11. Bistatic SAR: Proof of Concept.

    SciTech Connect

    Yocky, David A.; Doren, Neall E.; Bacon, Terry A.; Wahl, Daniel E.; Eichel, Paul H.; Jakowatz, Charles V,; Delaplain, Gilbert G.; Dubbert, Dale F.; Tise, Bertice L.; White, Kyle R.

    2014-10-01

    Typical synthetic aperture RADAR (SAR) imaging employs a co-located RADAR transmitter and receiver. Bistatic SAR imaging separates the transmitter and receiver locations. A bistatic SAR configuration allows for the transmitter and receiver(s) to be in a variety of geometric alignments. Sandia National Laboratories (SNL) / New Mexico proposed the deployment of a ground-based RADAR receiver. This RADAR receiver was coupled with the capability of digitizing and recording the signal collected. SNL proposed the possibility of creating an image of targets the illuminating SAR observes. This document describes the developed hardware, software, bistatic SAR configuration, and its deployment to test the concept of a ground-based bistatic SAR. In the proof-of-concept experiments herein, the RADAR transmitter will be a commercial SAR satellite and the RADAR receiver will be deployed at ground level, observing and capturing RADAR ground/targets illuminated by the satellite system.

  12. UAVSAR and TerraSAR-X Based InSAR Detection of Localized Subsidence in the New Orleans Area

    NASA Astrophysics Data System (ADS)

    Blom, R. G.; An, K.; Jones, C. E.; Latini, D.

    2014-12-01

    Vulnerability of the US Gulf coast to inundation has received increased attention since hurricanes Katrina and Rita. Compounding effects of sea level rise, wetland loss, and regional and local subsidence makes flood protection a difficult challenge, and particularly for the New Orleans area. Key to flood protection is precise knowledge of elevations and elevation changes. Analysis of historical and continuing geodetic measurements show surprising complexity, including locations subsiding more rapidly than considered during planning of hurricane protection and coastal restoration projects. Combining traditional, precise geodetic data with interferometric synthetic aperture radar (InSAR) observations can provide geographically dense constraints on surface deformation. The Gulf Coast environment is challenging for InSAR techniques, especially with systems not designed for interferometry. We use two InSAR capable systems, the L- band (24 cm wavelength) airborne JPL/NASA UAVSAR, and the DLR/EADS Astrium spaceborne TerraSAR X-band (3 cm wavelength), and compare results. First, we are applying pair-wise InSAR to the longer wavelength UAVSAR data to detect localized elevation changes potentially impacting flood protection infrastructure from 2009 - 2014. We focus on areas on and near flood protection infrastructure to identify changes indicative of subsidence, structural deformation, and/or seepage. The Spaceborne TerraSAR X-band SAR system has relatively frequent observations, and dense persistent scatterers in urban areas, enabling measurement of very small displacements. We compare L-band UAVSAR results with permanent scatterer (PS-InSAR) and Short Baseline Subsets (SBAS) interferometric analyses of a stack composed by 28 TerraSAR X-band images acquired over the same period. Thus we can evaluate results from the different radar frequencies and analyses techniques. Preliminary results indicate subsidence features potentially of a variety of causes, including ground water

  13. Comparison of immersed liquid and air cooling of NASA's Airborne Information Management System

    NASA Astrophysics Data System (ADS)

    Hoadley, A. W.; Porter, A. J.

    1992-07-01

    The Airborne Information Management System (AIMS) is currently under development at NASA Dryden Flight Research Facility. The AIMS is designed as a modular system utilizing surface mounted integrated circuits in a high-density configuration. To maintain the temperature of the integrated circuits within manufacturer's specifications, the modules are to be filled with Fluorinert FC-72. Unlike ground based liquid cooled computers, the extreme range of the ambient pressures experienced by the AIMS requires the FC-72 be contained in a closed system. This forces the latent heat absorbed during the boiling to be released during the condensation that must take within the closed module system. Natural convection and/or pumping carries the heat to the outer surface of the AIMS module where the heat transfers to the ambient air. This paper will present an evaluation of the relative effectiveness of immersed liquid cooling and air cooling of the Airborne Information Management System.

  14. Comparison of immersed liquid and air cooling of NASA's Airborne Information Management System

    NASA Technical Reports Server (NTRS)

    Hoadley, A. W.; Porter, A. J.

    1992-01-01

    The Airborne Information Management System (AIMS) is currently under development at NASA Dryden Flight Research Facility. The AIMS is designed as a modular system utilizing surface mounted integrated circuits in a high-density configuration. To maintain the temperature of the integrated circuits within manufacturer's specifications, the modules are to be filled with Fluorinert FC-72. Unlike ground based liquid cooled computers, the extreme range of the ambient pressures experienced by the AIMS requires the FC-72 be contained in a closed system. This forces the latent heat absorbed during the boiling to be released during the condensation that must take within the closed module system. Natural convection and/or pumping carries the heat to the outer surface of the AIMS module where the heat transfers to the ambient air. This paper will present an evaluation of the relative effectiveness of immersed liquid cooling and air cooling of the Airborne Information Management System.

  15. A prototype of an automated high resolution InSAR volcano-monitoring system in the MED-SUV project

    NASA Astrophysics Data System (ADS)

    Chowdhury, Tanvir A.; Minet, Christian; Fritz, Thomas

    2016-04-01

    Volcanic processes which produce a variety of geological and hydrological hazards are difficult to predict and capable of triggering natural disasters on regional to global scales. Therefore it is important to monitor volcano continuously and with a high spatial and temporal sampling rate. The monitoring of active volcanoes requires the reliable measurement of surface deformation before, during and after volcanic activities and it helps for the better understanding and modelling of the involved geophysical processes. Space-borne synthetic aperture radar (SAR) interferometry (InSAR), persistent scatterer interferometry (PSI) and small baseline subset algorithm (SBAS) provide a powerful tool for observing the eruptive activities and measuring the surface changes of millimetre accuracy. All the mentioned techniques with deformation time series extraction address the challenges by exploiting medium to large SAR image stacks. The process of selecting, ordering, downloading, storing, logging, extracting and preparing the data for processing is very time consuming has to be done manually for every single data-stack. In many cases it is even an iterative process which has to be done regularly and continuously. Therefore, data processing becomes slow which causes significant delays in data delivery. The SAR Satellite based High Resolution Data Acquisition System, which will be developed at DLR, will automate this entire time consuming tasks and allows an operational volcano monitoring system. Every 24 hours the system runs for searching new acquired scene over the volcanoes and keeps track of the data orders, log the status and download the provided data via ftp-transfer including E-Mail alert. Furthermore, the system will deliver specified reports and maps to a database for review and use by specialists. The user interaction will be minimized and iterative processes will be totally avoided. In this presentation, a prototype of SAR Satellite based High Resolution Data

  16. Very High Resolution SAR and Multichannel SAR/MTI

    DTIC Science & Technology

    2006-09-01

    single channel SAR system: • Detection outside the clutter bandwidth • Chirp slope analysis • Chirp filter bank • MTI via multilook images (change...53343 Wachtberg, Germany berens@fgan.de ABSTRACT SAR is widely used today in earth observation and is a potential means for military surveillance...However, systems only operating in the basic SAR mode will be superseded by new developments which fulfil much more user demands. Highest resolution

  17. Airborne Imagery

    NASA Technical Reports Server (NTRS)

    1983-01-01

    ATM (Airborne Thematic Mapper) was developed for NSTL (National Space Technology Companies) by Daedalus Company. It offers expanded capabilities for timely, accurate and cost effective identification of areas with prospecting potential. A related system is TIMS, Thermal Infrared Multispectral Scanner. Originating from Landsat 4, it is also used for agricultural studies, etc.

  18. Use of a new high-speed digital data acquisition system in airborne ice-sounding

    USGS Publications Warehouse

    Wright, David L.; Bradley, Jerry A.; Hodge, Steven M.

    1989-01-01

    A high-speed digital data acquisition and signal averaging system for borehole, surface, and airborne radio-frequency geophysical measurements was designed and built by the US Geological Survey. The system permits signal averaging at rates high enough to achieve significant signal-to-noise enhancement in profiling, even in airborne applications. The first field use of the system took place in Greenland in 1987 for recording data on a 150 by 150-km grid centered on the summit of the Greenland ice sheet. About 6000-line km were flown and recorded using the new system. The data can be used to aid in siting a proposed scientific corehole through the ice sheet.

  19. NASA/LMSC coherent LIDAR airborne shear sensor: System capabilities and flight test plans

    NASA Technical Reports Server (NTRS)

    Robinson, Paul

    1992-01-01

    The primary objective of the NASA/LMSC Coherent Lidar Airborne Shear Sensor (CLASS) system flight tests is to evaluate the capability of an airborne coherent lidar system to detect, measure, and predict hazardous wind shear ahead of the aircraft with a view to warning flight crew of any impending dangers. On NASA's Boeing 737 Transport Systems Research Vehicle, the CLASS system will be used to measure wind velocity fields and, by incorporating such measurements with real-time aircraft state parameters, identify regions of wind shear that may be detrimental to the aircraft's performance. Assessment is to be made through actual wind shear encounters in flight. Wind shear measurements made by the class system will be compared to those made by the aircraft's in situ wind shear detection system as well as by ground-based Terminal Doppler Weather Radar (TDWR) and airborne Doppler radar. By examining the aircraft performance loss (or gain) due to wind shear that the lidar predicts with that actually experienced by the aircraft, the performance of the CLASS system as a predictive wind shear detector will be assessed.

  20. SAR transmitter

    NASA Astrophysics Data System (ADS)

    1983-06-01

    In the follow-on of the ESA contract 4122/79 it was intended to demonstrate on breadboard the feasibility of a modular EPC supplied by a multibus for a KLYSTRON power transmitter. The aim of this final report is to give details on the design and on test results of the electronics required to drive a KLYSTRON for a SAR system. The concept utilized for the DC/DC conversion is a Series Resonant type (SCHWARZ Converter). An elegant Breadboard of 2 Modules (over 4 required for the complete EPC) has been realized and the tests have demonstrated the envisaged feasibility of an active redundancy with modular EPC both for output voltage generation and for output power. Also the concept of the multibus has been implemented (2 bus over 4) and verified in the EPC breadboard.

  1. SAR calibration technology review

    NASA Technical Reports Server (NTRS)

    Walker, J. L.; Larson, R. W.

    1981-01-01

    Synthetic Aperture Radar (SAR) calibration technology including a general description of the primary calibration techniques and some of the factors which affect the performance of calibrated SAR systems are reviewed. The use of reference reflectors for measurement of the total system transfer function along with an on-board calibration signal generator for monitoring the temporal variations of the receiver to processor output is a practical approach for SAR calibration. However, preliminary error analysis and previous experimental measurements indicate that reflectivity measurement accuracies of better than 3 dB will be difficult to achieve. This is not adequate for many applications and, therefore, improved end-to-end SAR calibration techniques are required.

  2. Geophex Airborne Unmanned Survey System (GAUSS). Topical report, October 1993--March 1995

    SciTech Connect

    1995-03-01

    The objectives of the project are to construct a geophysical sensor system based on a remotely operated model helicopter (ROH) and to evaluate the efficacy of the system for characterization of hazardous environmental sites. Geophex Airborne Unmanned Survey System (GAUSS) is a geophysical survey system that uses a ROH as the survey vehicle. We have selected the ROH because of its advantages over fixed wing and ground based vehicles. Lower air speed and superior maneuverability of the ROH make it better suited for geophysical surveys than a fixed wing model aircraft. The ROH can fly close to the ground, allowing detection of weak or subtle anomalies. Unlike ground based vehicles, the ROH can traverse difficult terrain while providing a stable sensor platform. ROH does not touch the ground during the course of a survey and is capable of functioning over water and surf zones. The ROH has been successfully used in the motion picture industry and by geology companies for payload bearing applications. The only constraint to use of the airborne system is that the ROH must remain visible to the pilot. Obstructed areas within a site can be characterized by relocating the base station to alternate positions. GAUSS consists of a ROH with radio controller, a data acquisition and processing (DAP) system, and lightweight digital sensor systems. The objective of our Phase I research was to develop a DAP and sensors suitable for ROH operation. We have constructed these subsystems and integrated them to produce an automated, hand-held geophysical surveying system, referred to as the ``pre-prototype``. We have performed test surveys with the pre-prototype to determine the functionality of the and DAP and sensor subsystems and their suitability for airborne application. The objective of the Phase II effort will be to modify the existing subsystems and integrate them into an airborne prototype. Efficacy of the prototype for geophysical survey of hazardous sites will then be determined.

  3. Multi-scale InSAR analysis of aseismic creep across the San Andreas, Calevaras,and Hayward Fault systems

    NASA Astrophysics Data System (ADS)

    Agram, P. S.; Simons, M.

    2011-12-01

    We apply the Multi-scale Interferometric Time-series (MInTS) technique, developed at Caltech,to study spatial variations in aseismic creep across the San Andreas, Calaveras and Hayward Faultsystems in Central California.Interferometric Synthetic Aperture Radar (InSAR) Time-series methods estimate the spatio-temporal evolution of surface deformation using multiple SAR interferograms. Traditional time-series analysis techniques like persistent scatterers and short baseline methods assume the statistical independence of InSAR phase measurements over space and time when estimating deformation. However, existing atmospheric phase screen models clearly show that noise in InSAR phase observations is correlated over the spatial domain. MInTS is an approach designed to exploit the correlation of phase observations over space to significantly improve the signal-to-noise ratio in the estimated deformation time-series compared to the traditional time-series InSAR techniques. The MInTS technique reduces the set of InSAR observations to a set of almost uncorrelated observations at various spatial scales using wavelets. Traditional inversion techniques can then be applied to the wavelet coefficients more effectively. Creep across the Central San Andreas Fault and the Hayward Fault has been studied previously using C-band (6 cm wavelength) ERS data, but detailed analysis of the transition zone between the San Andreas and Hayward Faults was not possible due to severe decorrelation. Improved coherence at L-band (24 cm wavelength) significantly improves the spatial coverage of the estimated deformation signal in our ALOS PALSAR data set. We analyze 450 ALOS PALSAR interferograms processed using 175 SAR images acquired between Dec 2006 and Dec 2010 that cover the area along the San Andreas Fault System from Richmond in the San Francisco Bay Area to Maricopa in the San Joaquin Valley.We invert the InSAR phase observations to estimate the constant Line-of-Sight (LOS) deformation

  4. Modeling and performance assessment in QinetiQ of EO and IR airborne reconnaissance systems

    NASA Astrophysics Data System (ADS)

    Williams, John W.; Potter, Gary E.

    2002-11-01

    QinetiQ are the technical authority responsible for specifying the performance requirements for the procurement of airborne reconnaissance systems, on behalf of the UK MoD. They are also responsible for acceptance of delivered systems, overseeing and verifying the installed system performance as predicted and then assessed by the contractor. Measures of functional capability are central to these activities. The conduct of these activities utilises the broad technical insight and wide range of analysis tools and models available within QinetiQ. This paper focuses on the tools, methods and models that are applicable to systems based on EO and IR sensors. The tools, methods and models are described, and representative output for systems that QinetiQ has been responsible for is presented. The principle capability applicable to EO and IR airborne reconnaissance systems is the STAR (Simulation Tools for Airborne Reconnaissance) suite of models. STAR generates predictions of performance measures such as GRD (Ground Resolved Distance) and GIQE (General Image Quality) NIIRS (National Imagery Interpretation Rating Scales). It also generates images representing sensor output, using the scene generation software CAMEO-SIM and the imaging sensor model EMERALD. The simulated image 'quality' is fully correlated with the predicted non-imaging performance measures. STAR also generates image and table data that is compliant with STANAG 7023, which may be used to test ground station functionality.

  5. Laser airborne remote sensing real-time acquisition, processing, and control system

    NASA Astrophysics Data System (ADS)

    Kelly, Brian T.; Pierson, Robert E.; Dropka, T. J.; Dowling, James A.; Lang, L. M.; Fox, Marsha J.

    1997-10-01

    The US Air Force Phillips Laboratory is evaluating the feasibility of long-standoff-range remote sensing of gaseous species present in trace amounts in the atmosphere. Extensive system integration in the laboratory and an airborne test are leading to remote sensing ground test and airborne missions within the next year. This paper describes the design, external interfaces. and initial performance of the Laser Airborne Remote Sensing acquisition, processing, and control system to be deployed on the Phillips Laboratory NC-135 research aircraft for differential absorption lidar system performance tests. The dual-CPU VME-based real-time computer system synchronizes experiment timing and pulsed CO2 laser operation up to 30 Hz while controlling optical subsystem components such as a laser grating, receiver gain, mirror alignment, and laser shutters. This real-time system acquires high rate detector signals from the outgoing and return laser pulses as well as a low rate health and status signals form the optical bench and the aircraft. Laser pulse and status data are processed and displayed in real time on one of four graphical user interfaces: one devoted to system control, one to remote mirror alignment, and two other interfaces for real-time data analysis and diagnostics. The dual-CPU and multi- layered software decouple time critical and non-critical tasks allowing great flexibility in flight-time display and processing.

  6. Airborne Windshear Detection and Warning Systems. Fifth and Final Combined Manufacturers' and Technologists' Conference, part 2

    NASA Technical Reports Server (NTRS)

    Delnore, Victor E. (Compiler)

    1994-01-01

    The Fifth Combined Manufacturers' and Technologists' Airborne Windshear Review Meeting was hosted by the NASA Langley Research Center and the Federal Aviation Administration in Hampton, Virginia, on September 28-30, 1993. The purpose was to report on the highly successful windshear experiments conducted by government, academic institutions, and industry; to transfer the results to regulators, manufacturers, and users; and to set initiatives for future aeronautics technology research. The formal sessions covered recent developments in windshear flight testing, windshear modeling, flight management, and ground-based systems, airborne windshear detection systems, certification and regulatory issues, and development and applications of sensors for wake vortices and for synthetic and enhanced vision systems. This report was compiled to record and make available the technology updates and materials from the conference.

  7. Airborne Windshear Detection and Warning Systems. Fifth and Final Combined Manufacturers' and Technologists' Conference, part 1

    NASA Technical Reports Server (NTRS)

    Delnore, Victor E. (Compiler)

    1994-01-01

    The Fifth (and Final) Combined Manufacturers' and Technologists' Airborne Windshear Review Meeting was hosted jointly by the NASA Langley Research Center (LaRC) and the Federal Aviation Administration (FAA) in Hampton, Virginia, on September 28-30, 1993. The purpose of the meeting was to report on the highly successful windshear experiments conducted by government, academic institutions, and industry; to transfer the results to regulators, manufacturers, and users; and to set initiatives for future aeronautics technology research. The formal sessions covered recent developments in windshear flight testing; windshear modeling, flight management, and ground-based systems; airborne windshear detection systems; certification and regulatory issues; development and applications of sensors for wake vortex detection; and synthetic and enhanced vision systems.

  8. Development of an airborne hydrocarbon monitoring system based on FTIR technology

    NASA Astrophysics Data System (ADS)

    Mogan, Paul A.; Mattson, Carl B.; Schwindt, Chris J.

    1998-10-01

    The capability to monitor airborne hydrocarbon compounds is essential in order to protect sensitive optical payloads from performance degradation caused by the deposition of surface films. Commonly used hydrocarbon monitoring instrumentation such as flame ionization detectors yield no information about the source or identity of compounds they detect. The Fourier Transform IR Spectrometer (FTIR) with its inherent ability to discriminate a large number of compounds offers a tremendous advantage over other types of instrumentation. The contamination monitoring laboratory at John F. Kennedy Space Center has developed an airborne hydrocarbon monitoring system based on FTIR technology to support the AXAF payload. This system consist of a portable cart suitable for use in Class 1 Division 2 environments. This paper describes the system in detail.

  9. Lightweight SAR/MTI for small UAV applications

    NASA Astrophysics Data System (ADS)

    Kirk, John C., Jr.

    2009-05-01

    Goleta has been developing low-cost and lite-weight MMW SAR / MTI radars for small UAS applications. Initial models of two different radars have been built, the LUAVR and the LCLPR. The current LUAVR (Lite-weight UAV radar) configuration weighs in at 18-lbs and the first LCLPR version (Low-Cost Low-Power Radar) weighs in at a little under 2-lbs. Initial testing was done from the roof of a van simulating a low flying UAV. Currently the LUAVR is flying in an ultra-lite as part of a UAS demonstration system. The system is comprised of both airborne and ground segments with a data link connecting the two. SAR and MTI Imagery have been generated.

  10. Design and Development of a Scanning Airborne Direct Detection Doppler Lidar System

    NASA Technical Reports Server (NTRS)

    Gentry, Bruce; McGill, Matthew; Schwemmer, Geary; Hardesty, Michael; Brewer, Alan; Wilkerson, Thomas; Atlas, Robert; Sirota, Marcos; Lindemann, Scott

    2006-01-01

    In the fall of 2005 we began developing an airborne scanning direct detection molecular Doppler lidar. The instrument is being built as part of the Tropospheric Wind Lidar Technology Experiment (TWiLiTE), a three year project selected by the NASA Earth Sun Technology Office under the Instrument Incubator Program. The TWiLiTE project is a collaboration involving scientists and engineers from NASA Goddard Space Flight Center, NOAA ESRL, Utah State University Space Dynamics Lab, Michigan Aerospace Corporation and Sigma Space Corporation. The TWiLiTE instrument will leverage significant research and development investments made by NASA Goddard and it's partners in the past several years in key lidar technologies and sub-systems (lasers, telescopes, scanning systems, detectors and receivers) required to enable spaceborne global wind lidar measurement. These sub-systems will be integrated into a complete molecular direct detection Doppler wind lidar system designed for autonomous operation on a high altitude aircraft, such as the NASA WB57. The WB57 flies at an altitude of 18 km and from this vantage point the nadir viewing Doppler lidar will be able to profile winds through the full troposphere. The TWiLiTE integrated airborne Doppler lidar instrument will be the first demonstration of a airborne scanning direct detection Doppler lidar and will serve as a critical milestone on the path to a future spaceborne tropospheric wind system. In addition to being a technology testbed for space based tropospheric wind lidar, when completed the TWiLiTE high altitude airborne lidar will be used for studying mesoscale dynamics and storm research (e.g. winter storms, hurricanes) and could be used for calibration and validation of satellite based wind systems such as ESA's Aeolus Atmospheric Dynamics Mission. The TWiLiTE Doppler lidar will have the capability to profile winds in clear air from the aircraft altitude of 18 km to the surface with 250 m vertical resolution and < 2mls

  11. Research Applications and Capabilities of the NASA/Army Rotorcraft Aircrew Systems Concepts Airborne Laboratory (RASCAL)

    NASA Technical Reports Server (NTRS)

    Aiken, Edwin W.; Jacobsen, Robert A.; Hindson, William S.

    1996-01-01

    The Rotorcraft Aircrew Systems Concepts Airborne Laboratory (RASCAL) is a UH-60 Black Hawk helicopter that is being modified by NASA and the US Army for flight systems research. The principal systems that are being installed in the aircraft are a Helmet-Mounted Display (HMD) and associated imaging systems, and a programmable full-authority Research Flight Control System (RFCS). In addition, comprehensive instrumentation of both the rigid body of the helicopter and the rotor system is provided. This paper describes the design features of this modern rotorcraft in-flight simulation facility and their current state of development. A brief description of initial research applications is included.

  12. Assessment of SAR and thermal changes near a cochlear implant system for mobile phone type exposures.

    PubMed

    McIntosh, Robert L; Iskra, Steve; McKenzie, Raymond J; Chambers, John; Metzenthen, Bill; Anderson, Vitas

    2008-01-01

    A cochlear implant system is a device used to enable hearing in people with severe hearing loss and consists of an internal implant and external speech processor. This study considers the effect of scattered radiofrequency fields when these persons are subject to mobile phone type exposure. A worst-case scenario is considered where the antenna is operating at nominal full power, the speech processor is situated behind the ear using a metallic hook, and the antenna is adjacent to the hook and the internal ball electrode. The resultant energy deposition and thermal changes were determined through numerical modelling. With a 900 MHz half-wave dipole antenna producing continuous-wave (CW) 250 mW power, the maximum 10 g averaged SAR was 1.31 W/kg which occurred in the vicinity of the hook and the ball electrode. The maximum temperature increase was 0.33 degrees C in skin adjacent to the hook. For the 1800 MHz antenna, operating at 125 mW, the maximum 10 g averaged SAR was 0.93 W/kg in the pinna whilst the maximum temperature change was 0.16 degrees C. The analysis predicts that the wearer complies with the radiofrequency safety limits specified by the International Commission on Non-Ionizing Radiation Protection (ICNIRP), the Institute of Electrical and Electronics Engineers (IEEE), and the Australian Radiation Protection and Nuclear Safety Agency (ARPANSA) for 900 and 1800 MHz mobile phone type exposure and thus raises no cause for concern. The resultant temperature increase is well below the maximum rise of 1 degrees C recommended by ICNIRP. Effects in the cochlea were insignificant.

  13. Flight Testing of an Advanced Airborne Natural Gas Leak Detection System

    SciTech Connect

    Dawn Lenz; Raymond T. Lines; Darryl Murdock; Jeffrey Owen; Steven Stearns; Michael Stoogenke

    2005-10-01

    ITT Industries Space Systems Division (Space Systems) has developed an airborne natural gas leak detection system designed to detect, image, quantify, and precisely locate leaks from natural gas transmission pipelines. This system is called the Airborne Natural Gas Emission Lidar (ANGEL) system. The ANGEL system uses a highly sensitive differential absorption Lidar technology to remotely detect pipeline leaks. The ANGEL System is operated from a fixed wing aircraft and includes automatic scanning, pointing system, and pilot guidance systems. During a pipeline inspection, the ANGEL system aircraft flies at an elevation of 1000 feet above the ground at speeds of between 100 and 150 mph. Under this contract with DOE/NETL, Space Systems was funded to integrate the ANGEL sensor into a test aircraft and conduct a series of flight tests over a variety of test targets including simulated natural gas pipeline leaks. Following early tests in upstate New York in the summer of 2004, the ANGEL system was deployed to Casper, Wyoming to participate in a set of DOE-sponsored field tests at the Rocky Mountain Oilfield Testing Center (RMOTC). At RMOTC the Space Systems team completed integration of the system and flew an operational system for the first time. The ANGEL system flew 2 missions/day for the duration for the 5-day test. Over the course of the week the ANGEL System detected leaks ranging from 100 to 5,000 scfh.

  14. Infection of Arabidopsis with a necrotrophic pathogen, Botrytis cinerea, elicits various defense responses but does not induce systemic acquired resistance (SAR).

    PubMed

    Govrin, Eri M; Levine, Alex

    2002-02-01

    Botrytis cinerea is a non-specific necrotrophic pathogen that attacks more than 200 plant species. In contrast to biotrophs, the necrotrophs obtain their nutrients by first killing the host cells. Many studies have shown that infection of plants by necrosis-causing pathogens induces a systemic acquired resistance (SAR), which provides protection against successive infections by a range of pathogenic organisms. We analyzed the role of SAR in B. cinerea infection of Arabidopsis. We show that although B. cinerea induced necrotic lesions and camalexin biosynthesis, it did not induce SAR-mediated protection against virulent strains of Pseudomonas syringae, or against subsequent B. cinerea infections. Induction of SAR with avirulent P. syringae or by chemical treatment with salicylic acid (SA) or benzothiadiazole also failed to inhibit B. cinerea growth, although removal of basal SA accumulation by expression of a bacterial salicylate hydroxylase (NahG) gene or by infiltration of 2-aminoindan-2-phosphonic acid, an inhibitor of phenylpropanoid pathway, increased B. cinerea disease symptoms. In addition, we show that B. cinerea induced expression of genes associated with SAR, general stress and ethylene/jasmonate-mediated defense pathways. Thus, B. cinerea does not induce SAR nor is it affected by SAR, making it a rare example of a necrogenic pathogen that does not cause SAR.

  15. ASPIS, A Flexible Multispectral System for Airborne Remote Sensing Environmental Applications

    PubMed Central

    Papale, Dario; Belli, Claudio; Gioli, Beniamino; Miglietta, Franco; Ronchi, Cesare; Vaccari, Francesco Primo; Valentini, Riccardo

    2008-01-01

    Airborne multispectral and hyperspectral remote sensing is a powerful tool for environmental monitoring applications. In this paper we describe a new system (ASPIS) composed by a 4-CCD spectral sensor, a thermal IR camera and a laser altimeter that is mounted on a flexible Sky-Arrow airplane. A test application of the multispectral sensor to estimate durum wheat quality is also presented. PMID:27879875

  16. Estimation of Separation Buffers for Wind-Prediction Error in an Airborne Separation Assistance System

    NASA Technical Reports Server (NTRS)

    Consiglio, Maria C.; Hoadley, Sherwood T.; Allen, B. Danette

    2009-01-01

    Wind prediction errors are known to affect the performance of automated air traffic management tools that rely on aircraft trajectory predictions. In particular, automated separation assurance tools, planned as part of the NextGen concept of operations, must be designed to account and compensate for the impact of wind prediction errors and other system uncertainties. In this paper we describe a high fidelity batch simulation study designed to estimate the separation distance required to compensate for the effects of wind-prediction errors throughout increasing traffic density on an airborne separation assistance system. These experimental runs are part of the Safety Performance of Airborne Separation experiment suite that examines the safety implications of prediction errors and system uncertainties on airborne separation assurance systems. In this experiment, wind-prediction errors were varied between zero and forty knots while traffic density was increased several times current traffic levels. In order to accurately measure the full unmitigated impact of wind-prediction errors, no uncertainty buffers were added to the separation minima. The goal of the study was to measure the impact of wind-prediction errors in order to estimate the additional separation buffers necessary to preserve separation and to provide a baseline for future analyses. Buffer estimations from this study will be used and verified in upcoming safety evaluation experiments under similar simulation conditions. Results suggest that the strategic airborne separation functions exercised in this experiment can sustain wind prediction errors up to 40kts at current day air traffic density with no additional separation distance buffer and at eight times the current day with no more than a 60% increase in separation distance buffer.

  17. Charge-coupled device data processor for an airborne imaging radar system

    NASA Technical Reports Server (NTRS)

    Arens, W. E. (Inventor)

    1977-01-01

    Processing of raw analog echo data from synthetic aperture radar receiver into images on board an airborne radar platform is discussed. Processing is made feasible by utilizing charge-coupled devices (CCD). CCD circuits are utilized to perform input sampling, presumming, range correlation and azimuth correlation in the analog domain. These radar data processing functions are implemented for single-look or multiple-look imaging radar systems.

  18. Precise SAR measurements in the near-field of RF antenna systems

    NASA Astrophysics Data System (ADS)

    Hakim, Bandar M.

    Wireless devices must meet specific safety radiation limits, and in order to assess the health affects of such devices, standard procedures are used in which standard phantoms, tissue-equivalent liquids, and miniature electric field probes are used. The accuracy of such measurements depend on the precision in measuring the dielectric properties of the tissue-equivalent liquids and the associated calibrations of the electric-field probes. This thesis describes work on the theoretical modeling and experimental measurement of the complex permittivity of tissue-equivalent liquids, and associated calibration of miniature electric-field probes. The measurement method is based on measurements of the field attenuation factor and power reflection coefficient of a tissue-equivalent sample. A novel method, to the best of the authors knowledge, for determining the dielectric properties and probe calibration factors is described and validated. The measurement system is validated using saline at different concentrations, and measurements of complex permittivity and calibration factors have been made on tissue-equivalent liquids at 900MHz and 1800MHz. Uncertainty analysis have been conducted to study the measurement system sensitivity. Using the same waveguide to measure tissue-equivalent permittivity and calibrate e-field probes eliminates a source of uncertainty associated with using two different measurement systems. The measurement system is used to test GSM cell-phones at 900MHz and 1800MHz for Specific Absorption Rate (SAR) compliance using a Specific Anthropomorphic Mannequin phantom (SAM).

  19. Design, calibration, and application of an airborne gamma spectrometer system in Switzerland

    SciTech Connect

    Schwarz, G.F.; Rybach, L.; Klingele, E.E.

    1997-09-01

    Airborne radiometric surveys are finding increasingly wider application in environmental mapping and monitoring. They are the most efficient tool to delimit surface contamination and to locate lost radioactive sources. To secure radiometric capability in survey and emergency situations, a new sensitive airborne system has been built that includes an airborne spectrometer with 256 channels and a sodium iodide detector with a total volume of 16.8 liters. A rack-mounted PC with memory cards is used for data acquisition, with a GPS satellite navigation system for positioning. The system was calibrated with point sources using a mathematical correction to take into account the effects of gamma-ray scattering in the ground and in the atmosphere. The calibration was complemented by high precision ground gamma spectrometry and laboratory measurements on rock samples. In Switzerland, two major research programs make use of the capabilities of airborne radiometric measurements. The first one concerns nuclear power-plant monitoring. The five Swiss nuclear installations (four power plants and one research facility) and the surrounding regions of each site are surveyed annually. The project goal is to monitor the dose-rate distribution and to provide a documented baseline database. The measurements show that all sites (with the exception of the Goesgen power plant) can be identified clearly on the maps. No artificial radioactivity that could not be explained by the Chernobyl release or earlier nuclear weapons tests was detected outside of the fenced sites of the nuclear installations. The second program aims at a better evaluation of the natural radiation level in Switzerland. The survey focused on the crystalline rocks of the Central Massifs of the Swiss Alps because of their relatively high natural radioactivity and lithological variability.

  20. The development of an airborne information management system for flight test

    NASA Technical Reports Server (NTRS)

    Bever, Glenn A.

    1992-01-01

    An airborne information management system is being developed at the NASA Dryden Flight Research Facility. This system will improve the state of the art in management data acquisition on-board research aircraft. The design centers around highly distributable, high-speed microprocessors that allow data compression, digital filtering, and real-time analysis. This paper describes the areas of applicability, approach to developing the system, potential for trouble areas, and reasons for this development activity. System architecture (including the salient points of what makes it unique), design philosophy, and tradeoff issues are also discussed.

  1. Impact of focusing of Ground Based SAR data on the quality of interferometric SAR applications

    NASA Astrophysics Data System (ADS)

    Zonno, Mariantonietta; Mascolo, Luigi; Guccione, Pietro; Nico, Giovanni; Di Pasquale, Andrea

    2014-10-01

    A Ground-Based Synthetic Aperture Radar (GB-SAR) is nowadays employed in several applications. The processing of ground-based, space and airborne SAR data relies on the same physical principles. Nevertheless specific algorithms for the focusing of data acquired by GB-SAR system have been proposed in literature. In this work the impact of the main focusing methods on the interferometric phase dispersion and on the coherence has been studied by employing a real dataset obtained by carrying out an experiment. Several acquisitions of a scene with a corner reflector mounted on a micrometric screw have been made; before some acquisitions the micrometric screw has been displaced of few millimetres in the Line-of-Sight direction. The images have been first focused by using two different algorithms and correspondently, two different sets of interferograms have been generated. The mean and standard deviation of the phase values in correspondence of the corner reflector have been compared to those obtained by knowing the real displacement of the micrometric screw. The mean phase and its dispersion and the coherence values for each focusing algorithm have been quantified and both the precision and the accuracy of the interferometic phase measurements obtained by using the two different focusing methods have been assessed.

  2. Research on the airborne SINS/CNS integrated navigation system assisted by BD navigation system

    NASA Astrophysics Data System (ADS)

    Xie, Mei-lin; Yang, Xiao-xu; Han, Jun-feng; Wei, Yu; Yue, Peng; Deng, Xiao-guo; Huang, Wei

    2016-01-01

    When the star navigation system working during the day, the strong sky background radiation lead to a result that the detect target light is too weak, in the field of view, because of the limitation on the number of the navigation star, usually choose the single star navigation work mode. In order to improve the reliability of the airborne SINS/CNS integrated navigation system, meet the demand of the long-endurance and high precision navigation, use the tight combination way, single star patrol algorithm to get the position and attitude. There exists filtering divergence problem because of the model error and the system measurement noise is uncertain, put forward a new fuzzy adaptive kalman filtering algorithm. Adjust the size of measurement noise to prevent the filter divergence; the positioning accuracy of integrated navigation system can be improved through BeiDou satellite. Without the information of BeiDou satellite, based on the level of the virtual reference, the navigation precision of integrated navigation system can be ensured over a period of time.

  3. Utilization of an Airborne Plant Chlorophyll Imaging System for Detection of Septic System Malfunction

    NASA Technical Reports Server (NTRS)

    Spiering, Bruce A.; Carter, Gregory A.

    2001-01-01

    Malfunctioning, or leaking, sewer systems increase the supply of water and nutrients to surface vegetation. Excess nutrients and harmful bacteria in the effluent pollute ground water and local water bodies and are dangerous to humans and the aquatic ecosystems. An airborne multispectral plant chlorophyll imaging system (PCIS) was used to identify growth patterns in the vegetation covering onsite and public sewer systems. The objective was to evaluate overall performance of the PCIS as well as to determine the best operational configuration for this application. The imaging system was flown in a light aircraft over selected locations Mobile County, Alabama. Calibration panels were used to help characterize instrument performance. Results demonstrated that the PCIS performed well and was capable of detecting septic leakage patterns from altitudes as high as 915 m. From 915 m, 6 of 18 sites were suspected to have sewage leakage. Subsequent ground inspections confirmed leakage on 3 of the 6 sites. From 610 m, 3 of 8 known leakage sites were detected. Tree cover and shadows near residential structures prevented detection of several known malfunctioning systems. Also some leakages known to occur in clear areas were not detected. False detections occurred in areas characterized by surface water drainage problems or recent excavation.

  4. Adaptive Stress Testing of Airborne Collision Avoidance Systems

    NASA Technical Reports Server (NTRS)

    Lee, Ritchie; Kochenderfer, Mykel J.; Mengshoel, Ole J.; Brat, Guillaume P.; Owen, Michael P.

    2015-01-01

    This paper presents a scalable method to efficiently search for the most likely state trajectory leading to an event given only a simulator of a system. Our approach uses a reinforcement learning formulation and solves it using Monte Carlo Tree Search (MCTS). The approach places very few requirements on the underlying system, requiring only that the simulator provide some basic controls, the ability to evaluate certain conditions, and a mechanism to control the stochasticity in the system. Access to the system state is not required, allowing the method to support systems with hidden state. The method is applied to stress test a prototype aircraft collision avoidance system to identify trajectories that are likely to lead to near mid-air collisions. We present results for both single and multi-threat encounters and discuss their relevance. Compared with direct Monte Carlo search, this MCTS method performs significantly better both in finding events and in maximizing their likelihood.

  5. Airborne multisensor pod system (AMPS) data: Multispectral data integration and processing hints

    SciTech Connect

    Leary, T.J.; Lamb, A.

    1996-11-01

    The Department of Energy`s Office of Arms Control and Non-Proliferation (NN-20) has developed a suite of airborne remote sensing systems that simultaneously collect coincident data from a US Navy P-3 aircraft. The primary objective of the Airborne Multisensor Pod System (AMPS) Program is {open_quotes}to collect multisensor data that can be used for data research, both to reduce interpretation problems associated with data overload and to develop information products more complete than can be obtained from any single sensor.{close_quotes} The sensors are housed in wing-mounted pods and include: a Ku-Band Synthetic Aperture Radar; a CASI Hyperspectral Imager; a Daedalus 3600 Airborne Multispectral Scanner; a Wild Heerbrugg RC-30 motion compensated large format camera; various high resolution, light intensified and thermal video cameras; and several experimental sensors (e.g. the Portable Hyperspectral Imager of Low-Light Spectroscopy (PHILLS)). Over the past year or so, the Coastal Marine Resource Assessment (CAMRA) group at the Florida Department of Environmental Protection`s Marine Research Institute (FMRI) has been working with the Department of Energy through the Naval Research Laboratory to develop applications and products from existing data. Considerable effort has been spent identifying image formats integration parameters. 2 refs., 3 figs., 2 tabs.

  6. Airborne Systems Software Acquisition Engineering Guidebook for Microprocessors and Firmware.

    DTIC Science & Technology

    1980-02-01

    cycle of your system? The cost to your system of loss of mass production support for your devices may be great . * Field support - Especially important if...specification - source of potential devide type proliferation. 0 Environment - devices must be evaluated and slash sheets published. 0 Economics - itis

  7. Pilot interaction with automated airborne decision making systems

    NASA Technical Reports Server (NTRS)

    Hammer, John M.

    1990-01-01

    Ways in which computers can aid the decision making of an human operator of an aerospace system are investigated. The approach taken is to aid rather than replace the human operator, because operational experience has shown that humans can enhance the effectiveness of systems. As systems become more automated, the role of the operator has shifted to that of a manager and problem solver. This shift has created the research area of how to aid the human in this role. Published research in four areas is described. A discussion is presented of the DC-8 flight simulator at Georgia Tech.

  8. Concept of Operations for Real-time Airborne Management System

    SciTech Connect

    Barr, Jonathan L.; Taira, Randal Y.; Orr, Heather M.

    2013-03-04

    The purpose of this document is to describe the operating concepts, capabilities, and benefits of RAMS including descriptions of how the system implementations can improve emergency response, damage assessment, task prioritization, and situation awareness. This CONOPS provides general information on operational processes and procedures required to utilize RAMS, and expected performance benefits of the system. The primary audiences for this document are the end users of RAMS (including flight operators and incident commanders) and the RAMS management team. Other audiences include interested offices within the Department of Homeland Security (DHS), and officials from other state and local jurisdictions who want to implement similar systems.

  9. Application of the Hardman methodology to the Single Channel Ground-Airborne Radio System (SINCGARS)

    NASA Technical Reports Server (NTRS)

    1984-01-01

    The HARDMAN methodology was applied to the various configurations of employment for an emerging Army multipurpose communications system. The methodology was used to analyze the manpower, personnel and training (MPT) requirements and associated costs, of the system concepts responsive to the Army's requirement for the Single Channel Ground-Airborne Radio System (SINCGARS). The scope of the application includes the analysis of two conceptual designs Cincinnati Electronics and ITT Aerospace/Optical Division for operating and maintenance support addressed through the general support maintenance echelon.

  10. Flight Tests of the DELICAT Airborne LIDAR System for Remote Clear Air Turbulence Detection

    NASA Astrophysics Data System (ADS)

    Vrancken, Patrick; Wirth, Martin; Ehret, Gerhard; Witschas, Benjamin; Veerman, Henk; Tump, Robert; Barny, Hervé; Rondeau, Philippe; Dolfi-Bouteyre, Agnès; Lombard, Laurent

    2016-06-01

    An important aeronautics application of lidar is the airborne remote detection of Clear Air Turbulence which cannot be performed with onboard radar. We report on a DLR-developed lidar system for the remote detection of such turbulent areas in the flight path of an aircraft. The lidar, consisting of a high-power UV laser transmitter and a direct detection system, was installed on a Dutch research aircraft. Flight tests executed in 2013 demonstrated the performance of the lidar system to detect local subtle variations in the molecular backscatter coefficient indicating the turbulence some 10 to 15 km ahead.

  11. Low Gravity Guidance System for Airborne Microgravity Research

    NASA Technical Reports Server (NTRS)

    Rieke, W. J.; Emery, E. F.; Boyer, E. O.; Hegedus, C.; ODonoghue, D. P.

    1996-01-01

    Microgravity research techniques have been established to achieve a greater understanding of the role of gravity in the fundamentals of a variety of physical phenomena and material processing. One technique in use at the NASA Lewis Research Center involves flying Keplarian trajectories with a modified Lear Jet and DC-9 aircraft to achieve a highly accurate Microgravity environment by neutralizing accelerations in all three axis of the aircraft. The Low Gravity Guidance System (LGGS) assists the pilot and copilot in flying the trajectories by displaying the aircraft acceleration data in a graphical display format. The Low Gravity Guidance System is a microprocessor based system that acquires and displays the aircraft acceleration information. This information is presented using an electroluminescent display mounted over the pilot's instrument panel. The pilot can select the Microgravity range that is required for a given research event. This paper describes the characteristics, design, calibration and testing of the Low Gravity Guidance System Phase 3, significant lessons from earlier systems and the developmental work on future systems.

  12. SAR (Synthetic Aperture Radar). Earth observing system. Volume 2F: Instrument panel report

    NASA Technical Reports Server (NTRS)

    1987-01-01

    The scientific and engineering requirements for the Earth Observing System (EOS) imaging radar are provided. The radar is based on Shuttle Imaging Radar-C (SIR-C), and would include three frequencies: 1.25 GHz, 5.3 GHz, and 9.6 GHz; selectable polarizations for both transmit and receive channels; and selectable incidence angles from 15 to 55 deg. There would be three main viewing modes: a local high-resolution mode with typically 25 m resolution and 50 km swath width; a regional mapping mode with 100 m resolution and up to 200 km swath width; and a global mapping mode with typically 500 m resolution and up to 700 km swath width. The last mode allows global coverage in three days. The EOS SAR will be the first orbital imaging radar to provide multifrequency, multipolarization, multiple incidence angle observations of the entire Earth. Combined with Canadian and Japanese satellites, continuous radar observation capability will be possible. Major applications in the areas of glaciology, hydrology, vegetation science, oceanography, geology, and data and information systems are described.

  13. SAR Imagery Applied to the Monitoring of Hyper-Saline Deposits: Death Valley Example (CA)

    NASA Technical Reports Server (NTRS)

    Lasne, Yannick; Paillou, Philippe; Freeman, Anthony; Chapman, Bruce

    2009-01-01

    The present study aims at understanding the influence of salinity on the dielectric constant of soils and then on the backscattering coeff cients recorded by airborne/spaceborne SAR systems. Based on dielectric measurements performed over hyper-saline deposits in Death Valley (CA), as well as laboratory electromagnetic characterization of salts and water mixtures, we used the dielectric constants as input parameters of analytical IEM simulations to model both the amplitude and phase behaviors of SAR signal at C, and L-bands. Our analytical simulations allow to reproduce specif c copolar signatures recorded in SAR data, corresponding to the Cottonball Basin saltpan. We also propose the copolar backscattering ratio and phase difference as indicators of moistened and salt-affected soils. More precisely, we show that these copolar indicators should allow to monitor the seasonal variations of the dielectric properties of saline deposits.

  14. MIRANDA 35 GHz SAR Based Non-Coherent Change Detection

    NASA Astrophysics Data System (ADS)

    Noetel, Denis; Kloeppel, Frank; Sieger, Stefan; Janssen, Daniel; Pohl, Nils

    2017-03-01

    Up to now, the high effort involved with airborne Synthetic Aperture Radar (SAR) systems has led to the effect that SAR image processing is mostly restricted to single images of a scene. Recent developments like the MIRANDA 35 and its matching flight platform allow for frequent revisits of the same scene at very high repeatability. MIRANDA 35 has been designed as a lightweight and compact SAR sensor for altitudes of up to 1 km while providing a resolution of 15 cm. In combination with a highly flexible ultralight aircraft we have recently obtained 28 measurements of a scene within 2 h of flight time at very high repeatability. Two sets of flight courses, each with 7 flyovers of the reference scene and 7 of a modified change scene, are investigated here using statistical change detection methods like Informational Difference and Universal Image Quality Index.

  15. Emergency Response Equipment and Related Training: Airborne Radiological Computer System (Model II)

    SciTech Connect

    David P. Colton

    2007-02-28

    The materials included in the Airborne Radiological Computer System, Model-II (ARCS-II) were assembled with several considerations in mind. First, the system was designed to measure and record the airborne gamma radiation levels and the corresponding latitude and longitude coordinates, and to provide a first overview look of the extent and severity of an accident's impact. Second, the portable system had to be light enough and durable enough that it could be mounted in an aircraft, ground vehicle, or watercraft. Third, the system must control the collection and storage of the data, as well as provide a real-time display of the data collection results to the operator. The notebook computer and color graphics printer components of the system would only be used for analyzing and plotting the data. In essence, the provided equipment is composed of an acquisition system and an analysis system. The data can be transferred from the acquisition system to the analysis system at the end of the data collection or at some other agreeable time.

  16. ATLAS: an airborne active linescan system for high-resolution topographic mapping

    NASA Astrophysics Data System (ADS)

    Willetts, David V.; Kightley, Peter J.; Mole, S. G.; Pearson, Guy N.; Pearson, P.; Coffey, Adrian S.; Stokes, Tim J.; Tapster, Paul R.; Westwood, M.

    2004-12-01

    High resolution ground mapping is of interest for survey and management of long linear features such as roads, railways and pipelines, and for georeferencing of areas such as flood plains for hydrological purposes. ATLAS (Airborne Topographic Laser System) is an active linescan system operating at the eyesafe wavelength of 1.5μm. Built for airborne survey, it is currently certified for use on a Twin Squirrel helicopter for operation from low levels to heights above 500 feet allowing commercial survey in built up areas. The system operates at a pulse repetition frequency of 56kHz with a line completed in 15ms, giving 36 points/m2 at the surface at the design flight speed. At each point the range to the ground is measured together with the scan angle of the system. This data is combined with a system attitude measurement from an integrated inertial navigation system and with system position derived from differential GPS data aboard the platform. A recording system captures the data with a synchronised time-stamp to enable post-processed reconstruction of a cloud of data points that will give a three-dimensional representation of the terrain, allowing the points to be located with respect to absolute Earth referenced coordinates to a precision of 5cm in three axes. This paper summarises the design, harmonisation, evaluation and performance of the system, and shows examples of survey data.

  17. Pilot interaction with automated airborne decision making systems

    NASA Technical Reports Server (NTRS)

    Rouse, W. B.; Chu, Y. Y.; Greenstein, J. S.; Walden, R. S.

    1976-01-01

    An investigation was made of interaction between a human pilot and automated on-board decision making systems. Research was initiated on the topic of pilot problem solving in automated and semi-automated flight management systems and attempts were made to develop a model of human decision making in a multi-task situation. A study was made of allocation of responsibility between human and computer, and discussed were various pilot performance parameters with varying degrees of automation. Optimal allocation of responsibility between human and computer was considered and some theoretical results found in the literature were presented. The pilot as a problem solver was discussed. Finally the design of displays, controls, procedures, and computer aids for problem solving tasks in automated and semi-automated systems was considered.

  18. Pilot interaction with automated airborne decision making systems

    NASA Technical Reports Server (NTRS)

    Rouse, W. B.; Hammer, J. M.; Morris, N. M.; Brown, E. N.; Yoon, W. C.

    1983-01-01

    The use of advanced software engineering methods (e.g., from artificial intelligence) to aid aircraft crews in procedure selection and execution is investigated. Human problem solving in dynamic environments as effected by the human's level of knowledge of system operations is examined. Progress on the development of full scale simulation facilities is also discussed.

  19. A Moored Airborne Video System with Nearshore Applications

    NASA Astrophysics Data System (ADS)

    Smith, G.; Lippmann, T.

    2004-12-01

    Over the past two decades researchers have developed video-based remote sensing techniques to measure relevant nearshore variables. Measurements made include spatial patterns in sand bar morphology, run-up oscillations, wave breaking distributions, phase speed and wave angle, and most recently, surface currents within the surf zone and swash. In general, vertical (i.e., downward oriented) photography or videography is preferred to high-oblique land-based systems. However, although aircraft-mounted video systems have been under development for several years, the relatively high cost and short dwell time has limited its widespread application. Thus, most video measurements for research applications are obtained through methods whereby arrays of video cameras are fixed on land and oriented obliquely to the surf zone region of interest. The typically high-oblique imagery is limited in spatial ground coverage by rapidly degrading resolution in the far field, as well as lay-over problems associated with a fluctuating sea surface and high incidence look-angle. In order to alleviate these problems, researchers have attempted mounting video (or photographic) sensors on tethered balloons where long time series can be obtained over large regions of the surf zone without limiting resolution in the far field. In our research we have developed a technique for mounting a video system onboard a tethered helikite, a combination kite and helium-filled blimp (Allsopp Helikites, Ltd.). The video system consists of a downward-looking video camera in a custom weather-proof housing mounted on the keel of the helikite. Also included are a differential GPS receiver, tilt and heading sensor for accurate geometrical transformation, micro-processor, onboard power supply, and wireless data link. In this presentation, we will discuss the system in more detail, the image resolution and accuracies, and the expected applications to nearshore processes research. This work is sponsored by the Office

  20. Flight Test Evaluation of Airborne Tire Pressure Indicating Systems.

    DTIC Science & Technology

    1979-09-01

    reasons they were not selected follows: Aoproaeh/Concent 1. Differential Valve - Discrete (Concept I, Part I Report) Differential valve opens when...system sensors are closed loop servo inclinometers, mounted on the bogie beam for main gear and inside the axle for the nose gear. 5. Go-No-Go Discrete...is an indication of a lack of symmetry between wheels of the same category. The differential level is set at 35 psi. If the particular tire is 35 psi

  1. Development of the Advance Warning Airborne System(AWAS)

    NASA Technical Reports Server (NTRS)

    Adamson, H. Patrick

    1992-01-01

    The thermal characteristics of microbursts are utilized by the AWAS IR and OAT features to provide predictive warning of hazardous microbursts ahead of the aircraft during landing or take off. The AWAS was evaluated satisfactorily in 1990 on a Cessna Citation that was intentionally flown into a number of wind shear events. The events were detected, and both the IR and OAT thermal features were shown to be effective. In 1991, AWAS units were flown on three American Airline MD-80's and three Northwest Airlines DC-9's to study and to decrease the nuisance alert response of the system. The AWAS was also flown on the NASA B737 during the summer of 1991. The results of these flights were inconclusive and disappointing. The results were not as promising as before because NASA conducted research flights which were outside of the normal operating envelope for which the AWAS is designed to operate. In an attempt to compensate for these differences in airspeed and mounting location, the automatic features of the system were sometimes overridden by NASA personnel during the flight. Each of these critical factors is discussed in detail. The effect of rain on the OAT signals is presented as a function of the air speed. Use of a 4 pole 1/20 Hertz filter is demonstrated by both the IR and thermal data. Participation in the NASA 1992 program was discussed. FAA direction in the continuing Certification program requires the addition of a reactive feature to the AWAS predictive system. This combined system will not require flight guidance on newer aircraft. The features of AWAS-IV, with the NASA algorithm included, were presented. Expected completion of the FAA Certification plan was also described.

  2. Airborne Antenna System for Minimum-Cycle-Slip GPS Reception

    NASA Technical Reports Server (NTRS)

    Wright, C. Wayne

    2009-01-01

    A system that includes a Global Positioning System (GPS) antenna and associated apparatus for keeping the antenna aimed upward has been developed for use aboard a remote-sensing-survey airplane. The purpose served by the system is to enable minimum- cycle-slip reception of GPS signals used in precise computation of the trajectory of the airplane, without having to restrict the airplane to maneuvers that increase the flight time needed to perform a survey. Cycle slip signifies loss of continuous track of the phase of a signal. Minimum-cycle-slip reception is desirable because maintaining constant track of the phase of the carrier signal from each available GPS satellite is necessary for surveying to centimeter or subcentimeter precision. Even a loss of signal for as short a time as a nanosecond can cause cycle slip. Cycle slips degrade the quality and precision of survey data acquired during a flight. The two principal causes of cycle slip are weakness of signals and multipath propagation. Heretofore, it has been standard practice to mount a GPS antenna rigidly on top of an airplane, and the radiation pattern of the antenna is typically hemispherical, so that all GPS satellites above the horizon are viewed by the antenna during level flight. When the airplane must be banked for a turn or other maneuver, the reception hemisphere becomes correspondingly tilted; hence, the antenna no longer views satellites that may still be above the Earth horizon but are now below the equatorial plane of the tilted reception hemisphere. Moreover, part of the reception hemisphere (typically, on the inside of a turn) becomes pointed toward ground, with a consequent increase in received noise and, therefore, degradation of GPS measurements. To minimize the likelihood of loss of signal and cycle slip, bank angles of remote-sensing survey airplanes have generally been limited to 10 or less, resulting in skidding or slipping uncoordinated turns. An airplane must be banked in order to make

  3. Motion compensation requirements for a high resolution spotlight SAR

    NASA Astrophysics Data System (ADS)

    Hepburn, J. S. A.; Haslam, G. E.; Liang, D. F.; Widnall, W. S.

    1986-07-01

    The Canadian Department of National Defence is developing a high resolution airborne spotlight synthetic aperture radar (SAR). To attain the high contrast, high resolution and low geometric distortion objectives of the project, it is essential that very accurate motion compensation be applied to the radar returns to minimize the effects on SAR image quality of spurious antenna phase center motion. The motion compensation system being developed for the project includes a gimballed master inertial navigation system (INS) located near the center of gravity of the host aircraft, a strapdown inertial measurement unit (IMU) comprising gyroscope and accelerometer triads mounted on the radar antenna, as well as Doppler velocity and barometric altitude sensors for damping the inertial systems. The role of the master INS is to enable high accuracy alignment of the strapdown IMU. The raw sensor data are integrated using a U-D factorized Kalman filter to obtain optimal estimates of the motion of the radar antenna phase center while the SAR window is open. The data are used to adjust both the radar pulse repetition frequency and the phase and displacement of the radar returns. An analysis of the motion compensation requirements was carried out, leading to the specification of the motion compensation sensor configuration and accuracy. The performance of the motion compensation system has been evaluated by detailed computer simulation. This evaluation accounted for all major system error sources, including errors associated with sensors, transfer alignment and computation, with the system operating in a moderately turbulent environment.

  4. Demonstration and Validation of an Improved Airborne Electromagnetic System for UXO Detection and Mapping

    DTIC Science & Technology

    2009-12-01

    Jefferson (Ohio) site, six acres in size, is located in an area where a glacial till layer, typically 50–200 feet (ft) thick, overlies Silurian age...lower cost per acre than ground-based systems. Furthermore, the data may be acquired in a shorter period of time. Airborne systems are particularly...Figure 6. 22 Alternating positive and negative "on-time" current pulses with linear on- and off-ramps are separated by "off-time" periods during

  5. Development of an Airborne Sea Ice Thickness Measurement System and Field Test Results

    DTIC Science & Technology

    1989-12-01

    Kovacs and J . Scott Holladay PJTIS CRA&I DTIC TAB Unannronced JustiCaton By Distribution I AvaIabilit Cordes AvjII d-dlc, Dist Prepared for U.S...Development of an Airborne Sea Ice Thickness Measurement System and Field Test Results 12. PERSONAL AUTHOR(S) Kovacs, Austin and Holladay, J . Scott 13a...Thickness Measurement System and Field Test Results AUSTIN KOVACS AND J . SCOTT HOLLADAY INTRODUCTION was determined to be desirable. The goals of the 1986-87

  6. A high gain antenna system for airborne satellite communication applications

    NASA Technical Reports Server (NTRS)

    Maritan, M.; Borgford, M.

    1990-01-01

    A high gain antenna for commercial aviation satellites communication is discussed. Electromagnetic and practical design considerations as well as candidate systems implementation are presented. An evaluation of these implementation schemes is given, resulting in the selection of a simple top mounted aerodynamic phased array antenna with a remotely located beam steering unit. This concept has been developed into a popular product known as the Canadian Marconi Company CMA-2100. A description of the technical details is followed by a summary of results from the first production antennas.

  7. Pilot interaction with automated airborne decision making systems

    NASA Technical Reports Server (NTRS)

    Hammer, John M.; Wan, C. Yoon; Vasandani, Vijay

    1987-01-01

    The current research is focused on detection of human error and protection from its consequences. A program for monitoring pilot error by comparing pilot actions to a script was described. It dealt primarily with routine errors (slips) that occurred during checklist activity. The model to which operator actions were compared was a script. Current research is an extension along these two dimensions. The ORS fault detection aid uses a sophisticated device model rather than a script. The newer initiative, the model-based and constraint-based warning system, uses an even more sophisticated device model and is to prevent all types of error, not just slips or bad decision.

  8. Portable Airborne Laser System Measures Forest-Canopy Height

    NASA Technical Reports Server (NTRS)

    Nelson, Ross

    2005-01-01

    (PALS) is a combination of laser ranging, video imaging, positioning, and data-processing subsystems designed for measuring the heights of forest canopies along linear transects from tens to thousands of kilometers long. Unlike prior laser ranging systems designed to serve the same purpose, the PALS is not restricted to use aboard a single aircraft of a specific type: the PALS fits into two large suitcases that can be carried to any convenient location, and the PALS can be installed in almost any local aircraft for hire, thereby making it possible to sample remote forests at relatively low cost. The initial cost and the cost of repairing the PALS are also lower because the PALS hardware consists mostly of commercial off-the-shelf (COTS) units that can easily be replaced in the field. The COTS units include a laser ranging transceiver, a charge-coupled-device camera that images the laser-illuminated targets, a differential Global Positioning System (dGPS) receiver capable of operation within the Wide Area Augmentation System, a video titler, a video cassette recorder (VCR), and a laptop computer equipped with two serial ports. The VCR and computer are powered by batteries; the other units are powered at 12 VDC from the 28-VDC aircraft power system via a low-pass filter and a voltage converter. The dGPS receiver feeds location and time data, at an update rate of 0.5 Hz, to the video titler and the computer. The laser ranging transceiver, operating at a sampling rate of 2 kHz, feeds its serial range and amplitude data stream to the computer. The analog video signal from the CCD camera is fed into the video titler wherein the signal is annotated with position and time information. The titler then forwards the annotated signal to the VCR for recording on 8-mm tapes. The dGPS and laser range and amplitude serial data streams are processed by software that displays the laser trace and the dGPS information as they are fed into the computer, subsamples the laser range and

  9. An Improved Platform Levelling System for Airborne Gravity Meters.

    NASA Astrophysics Data System (ADS)

    Brady, N.

    2014-12-01

    Recent advances in sensor technology have enabled Lacoste and Romberg type relative gravity meters to improve in accuracy to the point where other non-sensor related sources of error serve to limit the overall accuracy of the system. One of these sources of error is derived from the inability of the platform, in which the sensor is mounted, to keep the sensor perfectly level during survey flight. Off level errors occur when the aircraft is unable to maintain straight and level flight along a survey line. The levelling platform of a typical Lacoste and Romberg type dynamic gravity meter utilizes a complex feedback loop involving both accelerometers and gyroscopes with an output connected to torque motors mounted to the platform to sense an off level situation and correct for it. The current system is limited by an inability of the platform to distinguish between an acceleration of the platform due to a change in heading, altitude or speed of the aircraft and a true change in the local gravity vertical. Both of these situations cause the platform to tilt in reponse however the aircraft acceleration creates an error in the gravity measurement. These off level errors can be corrected for to a limited degree depending on the algorithm used and the size and duration of the causal acceleration. High precision GPS now provides accurate real time position information which can be used to determine if an accleration is a real level change or due to an anomalous acceleration. The correct implementation of the GPS position can significantly improve the accuracy of the platform levelling including keeping the platform level during course reversals or drape flying during a survey. This can typically improve the quality of the gravity data before any processing corrections. The enhanced platform also reduces the time taken to stabilize the platform at the beginning of a survey line therefore improving the efficiency of the data collection. This paper discusses the method and

  10. Optimization of an air–liquid interface exposure system for assessing toxicity of airborne nanoparticles

    PubMed Central

    Latvala, Siiri; Hedberg, Jonas; Möller, Lennart; Odnevall Wallinder, Inger; Karlsson, Hanna L.

    2016-01-01

    Abstract The use of refined toxicological methods is currently needed for characterizing the risks of airborne nanoparticles (NPs) to human health. To mimic pulmonary exposure, we have developed an air–liquid interface (ALI) exposure system for direct deposition of airborne NPs on to lung cell cultures. Compared to traditional submerged systems, this allows more realistic exposure conditions for characterizing toxicological effects induced by airborne NPs. The purpose of this study was to investigate how the deposition of silver NPs (AgNPs) is affected by different conditions of the ALI system. Additionally, the viability and metabolic activity of A549 cells was studied following AgNP exposure. Particle deposition increased markedly with increasing aerosol flow rate and electrostatic field strength. The highest amount of deposited particles (2.2 μg cm–2) at cell‐free conditions following 2 h exposure was observed for the highest flow rate (390 ml min–1) and the strongest electrostatic field (±2 kV). This was estimated corresponding to deposition efficiency of 94%. Cell viability was not affected after 2 h exposure to clean air in the ALI system. Cells exposed to AgNPs (0.45 and 0.74 μg cm–2) showed significantly (P < 0.05) reduced metabolic activities (64 and 46%, respectively). Our study shows that the ALI exposure system can be used for generating conditions that were more realistic for in vitro exposures, which enables improved mechanistic and toxicological studies of NPs in contact with human lung cells.Copyright © 2016 The Authors Journal of Applied Toxicology Published by John Wiley & Sons Ltd. PMID:26935862

  11. Optimization of an air-liquid interface exposure system for assessing toxicity of airborne nanoparticles.

    PubMed

    Latvala, Siiri; Hedberg, Jonas; Möller, Lennart; Odnevall Wallinder, Inger; Karlsson, Hanna L; Elihn, Karine

    2016-10-01

    The use of refined toxicological methods is currently needed for characterizing the risks of airborne nanoparticles (NPs) to human health. To mimic pulmonary exposure, we have developed an air-liquid interface (ALI) exposure system for direct deposition of airborne NPs on to lung cell cultures. Compared to traditional submerged systems, this allows more realistic exposure conditions for characterizing toxicological effects induced by airborne NPs. The purpose of this study was to investigate how the deposition of silver NPs (AgNPs) is affected by different conditions of the ALI system. Additionally, the viability and metabolic activity of A549 cells was studied following AgNP exposure. Particle deposition increased markedly with increasing aerosol flow rate and electrostatic field strength. The highest amount of deposited particles (2.2 μg cm(-2) ) at cell-free conditions following 2 h exposure was observed for the highest flow rate (390 ml min(-1) ) and the strongest electrostatic field (±2 kV). This was estimated corresponding to deposition efficiency of 94%. Cell viability was not affected after 2 h exposure to clean air in the ALI system. Cells exposed to AgNPs (0.45 and 0.74 μg cm(-2) ) showed significantly (P < 0.05) reduced metabolic activities (64 and 46%, respectively). Our study shows that the ALI exposure system can be used for generating conditions that were more realistic for in vitro exposures, which enables improved mechanistic and toxicological studies of NPs in contact with human lung cells.Copyright © 2016 The Authors Journal of Applied Toxicology Published by John Wiley & Sons Ltd.

  12. Artificial Immune System Approach for Airborne Vehicle Maneuvering

    NASA Technical Reports Server (NTRS)

    Kaneshige, John T. (Inventor); Krishnakumar, Kalmanje S. (Inventor)

    2014-01-01

    A method and system for control of a first aircraft relative to a second aircraft. A desired location and desired orientation are estimated for the first aircraft, relative to the second aircraft, at a subsequent time, t=t2, subsequent to the present time, t=t1, where the second aircraft continues its present velocity during a subsequent time interval, t1.ltoreq.t.ltoreq.t2, or takes evasive action. Action command sequences are examined, and an optimal sequence is chosen to bring the first aircraft to the desired location and desired orientation relative to the second aircraft at time t=t2. The method applies to control of combat aircraft and/or of aircraft in a congested airspace.

  13. Lidar System for Airborne Measurement of Clouds and Aerosols

    NASA Technical Reports Server (NTRS)

    McGill, Matthew; Scott, V. Stanley; Izquierdo, Luis Ramos; Marzouk, Joe

    2008-01-01

    A lidar system for measuring optical properties of clouds and aerosols at three wavelengths is depicted. The laser transmitter is based on a Nd:YVO4 laser crystal pumped by light coupled to the crystal via optical fibers from laser diodes that are located away from the crystal to aid in dissipating the heat generated in the diodes and their drive circuits. The output of the Nd:YVO4 crystal has a wavelength of 1064 nm, and is made to pass through frequency-doubling and frequency-tripling crystals. As a result, the net laser output is a collinear superposition of beams at wavelengths of 1064, 532, and 355 nm. The laser operates at a pulse-repetition rate of 5 kHz, emitting per-pulse energies of 50 microJ at 1064 nm, 25 microJ at 532 nm and 50 microJ at 355 nm. An important feature of this system is an integrating sphere located between the laser output and the laser beam expander lenses. The integrating sphere collects light scattered from the lenses. Three energy-monitor detectors are located at ports inside the integrating sphere. Each of these detectors is equipped with filters such that the laser output energy is measured independently for each wavelength. The laser output energy is measured on each pulse to enable the most accurate calibration possible. The 1064-nm and 532-nm photodetectors are, more specifically, single photon-counting modules (SPCMs). When used at 1064 nm, these detectors have approximately 3% quantum efficiency and low thermal noise (fewer than 200 counts per second). When used at 532 nm, the SPCMs have quantum efficiency of about 60%. The photodetector for the 355-nm channel is a photon-counting photomultiplier tube having a quantum efficiency of about 20%. The use of photon-counting detectors is made feasible by the low laser pulse energy. The main advantage of photon-counting is ease of inversion of data without need for complicated calibration schemes like those necessary for analog detectors. The disadvantage of photon-counting detectors

  14. System for rapid detection of antibiotic resistance of airborne pathogens

    NASA Astrophysics Data System (ADS)

    Fortin, M.; Noiseux, I.; Mouslinkina, L.; Vernon, M. L.; Laflamme, C.; Filion, G.; Duchaine, C.; Ho, J.

    2009-05-01

    This project uses function-based detection via a fundamental understanding of the genetic markers of AR to distinguish harmful organisms from innocuous ones. This approach circumvents complex analyses to unravel the taxonomic details of 1399 pathogen species, enormously simplifying detection requirements. Laval Hospital's fast permeabilization strategy enables AR revelation in <1hr. Packaging the AR protocols in liquid-processing cartridges and coupling these to our in-house miniature fiber optic flow cell (FOFC) provides first responders with timely information on-site. INO's FOFC platform consists of a specialty optical fiber through which a hole is transversally bored by laser micromachining. The analyte solution is injected into the hole of the fiber and the particles are detected and counted. The advantage with respect to classic free space FC is that alignment occurs in the fabrication process only and complex excitation and collection optics are replaced by optical fibers. Moreover, we use a sheathless configuration which has the advantage of increase the portability of the system, to reduce excess biohazard material and the need for weekly maintenance. In this paper we present the principle of our FOFC along with a, demonstration of the basic capability of the platform for detection of bacillus cereus spores using permeabilized staining.

  15. Millimeter wave radar system on a rotating platform for combined search and track functionality with SAR imaging

    NASA Astrophysics Data System (ADS)

    Aulenbacher, Uwe; Rech, Klaus; Sedlmeier, Johannes; Pratisto, Hans; Wellig, Peter

    2014-10-01

    Ground based millimeter wave radar sensors offer the potential for a weather-independent automatic ground surveillance at day and night, e.g. for camp protection applications. The basic principle and the experimental verification of a radar system concept is described, which by means of an extreme off-axis positioning of the antenna(s) combines azimuthal mechanical beam steering with the formation of a circular-arc shaped synthetic aperture (SA). In automatic ground surveillance the function of search and detection of moving ground targets is performed by means of the conventional mechanical scan mode. The rotated antenna structure designed as a small array with two or more RX antenna elements with simultaneous receiver chains allows to instantaneous track multiple moving targets (monopulse principle). The simultaneously operated SAR mode yields areal images of the distribution of stationary scatterers. For ground surveillance application this SAR mode is best suited for identifying possible threats by means of change detection. The feasibility of this concept was tested by means of an experimental radar system comprising of a 94 GHz (W band) FM-CW module with 1 GHz bandwidth and two RX antennas with parallel receiver channels, placed off-axis at a rotating platform. SAR mode and search/track mode were tested during an outdoor measurement campaign. The scenery of two persons walking along a road and partially through forest served as test for the capability to track multiple moving targets. For SAR mode verification an image of the area composed of roads, grassland, woodland and several man-made objects was reconstructed from the measured data.

  16. Concentration and characterization of airborne particles in Tehran's subway system.

    PubMed

    Kamani, Hosein; Hoseini, Mohammad; Seyedsalehi, Mahdi; Mahdavi, Yousef; Jaafari, Jalil; Safari, Gholam Hosein

    2014-06-01

    Particulate matter is an important air pollutant, especially in closed environments like underground subway stations. In this study, a total of 13 elements were determined from PM10 and PM2.5 samples collected at two subway stations (Imam Khomeini and Sadeghiye) in Tehran's subway system. Sampling was conducted in April to August 2011 to measure PM concentrations in platform and adjacent outdoor air of the stations. In the Imam Khomeini station, the average concentrations of PM10 and PM2.5 were 94.4 ± 26.3 and 52.3 ± 16.5 μg m(-3) in the platform and 81.8 ± 22.2 and 35 ± 17.6 μg m(-3) in the outdoor air, respectively. In the Sadeghiye station, mean concentrations of PM10 and PM2.5 were 87.6 ± 23 and 41.3 ± 20.4 μg m(-3) in the platform and 73.9 ± 17.3 and 30 ± 15 μg m(-3), in the outdoor air, respectively. The relative contribution of elemental components in each particle fraction were accounted for 43% (PM10) and 47.7% (PM2.5) in platform of Imam Khomeini station and 15.9% (PM10) and 18.5% (PM2.5) in the outdoor air of this station. Also, at the Sadeghiye station, each fraction accounted for 31.6% (PM10) and 39.8% (PM2.5) in platform and was 11.7% (PM10) and 14.3% (PM2.5) in the outdoor. At the Imam Khomeini station, Fe was the predominant element to represent 32.4 and 36 % of the total mass of PM10 and PM2.5 in the platform and 11.5 and 13.3% in the outdoor, respectively. At the Sadeghiye station, this element represented 22.7 and 29.8% of total mass of PM10 and PM2.5 in the platform and 8.7 and 10.5% in the outdoor air, respectively. Other major crustal elements were 5.8% (PM10) and 5.3% (PM2.5) in the Imam Khomeini station platform and 2.3 and 2.4% in the outdoor air, respectively. The proportion of other minor elements was significantly lower, actually less than 7% in total samples, and V was the minor concentration in total mass of PM10 and PM2.5 in both platform stations.

  17. An Integrated Data Acquisition / User Request/ Processing / Delivery System for Airborne Remote Sensing Data

    NASA Astrophysics Data System (ADS)

    Chapman, B.; Chu, A.; Tung, W.

    2003-12-01

    Airborne science data has historically played an important role in the development of the scientific underpinnings for spaceborne missions. When the science community determines the need for new types of spaceborne measurements, airborne campaigns are often crucial in risk mitigation for these future missions. However, full exploitation of the acquired data may be difficult due to its experimental and transitory nature. Externally to the project, most problematic (in particular, for those not involved in requesting the data acquisitions) may be the difficulty in searching for, requesting, and receiving the data, or even knowing the data exist. This can result in a rather small, insular community of users for these data sets. Internally, the difficulty for the project is in maintaining a robust processing and archival system during periods of changing mission priorities and evolving technologies. The NASA/JPL Airborne Synthetic Aperture Radar (AIRSAR) has acquired data for a large and varied community of scientists and engineers for 15 years. AIRSAR is presently supporting current NASA Earth Science Enterprise experiments, such as the Soil Moisture EXperiment (SMEX) and the Cold Land Processes experiment (CLPX), as well as experiments conducted as many as 10 years ago. During that time, it's processing, data ordering, and data delivery system has undergone evolutionary change as the cost and capability of resources has improved. AIRSAR now has a fully integrated data acquisition/user request/processing/delivery system through which most components of the data fulfillment process communicate via shared information within a database. The integration of these functions has reduced errors and increased throughput of processed data to customers.

  18. Basis for optronic ScanSAR processing

    NASA Astrophysics Data System (ADS)

    Marchese, Linda; Bourqui, Pascal; Turgeon, Sandra; Harnish, Bernd; Suess, Martin; Châteauneuf, François; Bergeron, Alain

    2011-11-01

    ScanSAR is an important imaging mode of operation for SAR systems. It allows extended range coverage albeit at the expense of azimuth resolution. Compared to stripmap, ScanSAR is used more for large swath coverage for mapping and monitoring over a wide area. Applications are numerous and include boreal forest mapping, wetland mapping and soil moisture monitoring. The goal of the present work was thus to explore the possibility of processing ScanSAR data optronicaly. Tests were performed with artificially bursted ASAR stripmap data demonstrating that reconstruction of ScanSAR data using the optronic SAR processor is feasible. This paper describes specifically how the data control and handling of ScanSAR data is performed to make it compatible with the optronic processor that was otherwise specifically designed for stripmap processing. As well, the ScanSAR images generated optronicaly are presented.

  19. Positional Accuracy of Airborne Integrated Global Positioning and Inertial Navigation Systems for Mapping in Glen Canyon, Arizona

    USGS Publications Warehouse

    Sanchez, Richard D.; Hothem, Larry D.

    2002-01-01

    High-resolution airborne and satellite image sensor systems integrated with onboard data collection based on the Global Positioning System (GPS) and inertial navigation systems (INS) may offer a quick and cost-effective way to gather accurate topographic map information without ground control or aerial triangulation. The Applanix Corporation?s Position and Orientation Solutions for Direct Georeferencing of aerial photography was used in this project to examine the positional accuracy of integrated GPS/INS for terrain mapping in Glen Canyon, Arizona. The research application in this study yielded important information on the usefulness and limits of airborne integrated GPS/INS data-capture systems for mapping.

  20. First results from an airborne GPS radio occultation system for atmospheric profiling

    NASA Astrophysics Data System (ADS)

    Haase, J. S.; Murphy, B. J.; Muradyan, P.; Nievinski, F. G.; Larson, K. M.; Garrison, J. L.; Wang, K.-N.

    2014-03-01

    Global Positioning System (GPS) radio occultation (RO) from low Earth-orbiting satellites has increased the quantity of high-vertical resolution atmospheric profiles, especially over oceans, and has significantly improved global weather forecasting. A new system, the Global Navigation Satellite Systems Instrument System for Multistatic and Occultation Sensing (GISMOS), has been developed for RO sounding from aircraft. GISMOS also provides high-vertical resolution profiles that are insensitive to clouds and precipitation, and in addition, provides greater control on the sampling location, useful for targeted regional studies. The feasibility of the system is demonstrated with a flight carried out during development of an Atlantic tropical storm. The data have been evaluated through a comparison with dropsonde data. The new airborne RO system will effectively increase by more than 50% the number of profiles available for studying the evolution of tropical storms during this campaign and could potentially be deployed on commercial aircraft in the future.

  1. Recent advances in the applications of pulsed lasers in the hydrosphere. [considering airborne bathymetry system

    NASA Technical Reports Server (NTRS)

    Hickman, G. D.

    1975-01-01

    Laboratory and field measurements have been performed on the transmission/scattering characteristics of a pulsed neon laser as a function of water turbidity. These results have been used to establish the criteria for an airborne laser bathymetry system. Extensive measurements have been made of laser induced fluorescence using a pulsed tunable dye laser. Feasibility has been demonstrated for remote detection and possible identification of various types of algae and oils. Similar measurements made on a wide variety of organic dyes have shown this technique to have applications in remote measurements of subsurface currents, temperature and salinity.

  2. A Performance Assessment of a Tactical Airborne Separation Assistance System using Realistic, Complex Traffic Flows

    NASA Technical Reports Server (NTRS)

    Smith, Jeremy C.; Neitzke, Kurt W.; Bussink, Frank J. L.

    2008-01-01

    This paper presents the results from a study that investigates the performance of aspects of an Airborne Separation Assistance System (ASAS) under varying demand levels using realistic traffic patterns. This study only addresses the tactical aspects of an ASAS using aircraft state data (latitude, longitude, altitude, heading and speed) to detect and resolve projected conflicts. The main focus of this paper is to determine the extent to which sole reliance on the proposed tactical ASAS can maintain aircraft separation at demand levels up to three times current traffic. The effect of mixing ASAS equipped aircraft with non-equipped aircraft that do not have the capability to self-separate is also investigated.

  3. High-energy, efficient, 30-Hz ultraviolet laser sources for airborne ozone-lidar systems.

    PubMed

    Elsayed, Khaled A; Chen, Songsheng; Petway, Larry B; Meadows, Byron L; Marsh, Waverly D; Edwards, William C; Barnes, James C; DeYoung, Russell J

    2002-05-20

    Two compact, high-pulse-energy, injection-seeded, 30-Hz frequency-doubled Nd:YAG-laser-pumped Ti: sapphire lasers were developed and operated at infrared wavelengths of 867 and 900 nm. Beams with laser pulse energy >30 mJ at ultraviolet wavelengths of 289 and 300 nm were generated through a tripling of the frequencies of these Ti:sapphire lasers. This work is directed at the replacement of dye lasers for use in an airborne ozone differential absorption lidar system. The ultraviolet pulse energy at 289 and 300 nm had 27% and 31% absolute optical energy conversion efficiencies from input pulse energies at 867 and 900 nm, respectively.

  4. [About the improvement of communication system and information transmission in medical service control in airborne division].

    PubMed

    Korniushko, I G; Shelepov, A M; Zhidik, V V; Berezin, A I

    2007-03-01

    Frequent changes in tactical, rear and medical situations cause the medical service officials of airborne division (ABD) to obtain and transmit the data characterizing the medical service forces and means for a lot of times. It decreases the effectiveness of the control process. Equipping of ABD medical service staff with programming-and-technical systems (PTS), development of algorithm of official interaction, creation of report forms and selection of materials necessary for PTS database input will contribute to the effectiveness of ABD medical service control.

  5. Airborne antenna coverage requirements for the TCV B-737 aircraft. [for operation with microwave landing systems

    NASA Technical Reports Server (NTRS)

    Southall, W. A., Jr.; White, W. F.

    1978-01-01

    The airborne antenna line of sight look angle requirement for operation with a Microwave Landing System (MLS) was studied. The required azimuth and elevation line of sight look angles from an antenna located on an aircraft to three ground based antenna sites at the Wallops Flight Center (FPS-16 radar, MLS aximuth, and MLS elevation) as the aircraft follows specific approach paths selected as representative of MLS operations at the Denver, Colorado, terminal area are presented. These required azimuth and elevation look angles may be interpreted as basic design requirements for antenna of the TCV B-737 airplane for MLS operations along these selected approach paths.

  6. Advanced Antenna Design for NASA's EcoSAR Instrument

    NASA Technical Reports Server (NTRS)

    Du Toit, Cornelis F.; Deshpande, Manohar; Rincon, Rafael F.

    2016-01-01

    Advanced antenna arrays were designed for NASA's EcoSAR airborne radar instrument. EcoSAR is a beamforming synthetic aperture radar instrument designed to make polarimetric and "single pass" interferometric measurements of Earth surface parameters. EcoSAR's operational requirements of a 435MHz center frequency with up to 200MHz bandwidth, dual polarization, high cross-polarization isolation (> 30 dB), +/- 45deg beam scan range and antenna form-factor constraints imposed stringent requirements on the antenna design. The EcoSAR project successfully developed, characterized, and tested two array antennas in an anechoic chamber. EcoSAR's first airborne campaign conducted in the spring of 2014 generated rich data sets of scientific and engineering value, demonstrating the successful operation of the antennas.

  7. An Airborne Scanning LiDAR System for Ocean and Coastal Applications

    NASA Astrophysics Data System (ADS)

    Reineman, B. D.; Lenain, L.; Castel, D.; Melville, W. K.

    2008-12-01

    We have developed an airborne scanning LiDAR (Light Detection And Ranging) system and demonstrated its functionality for terrestrial and oceanographic measurements. Differential GPS (DGPS) and an Inertial Navigation System (INS) are synchronized with the LiDAR, providing end result vertical rms errors of approximately 6~cm. Flying 170~m above the surface, we achieve a point density of ~ 0.7 m-2 and a swath width of 90 to 120~m over ocean and 200~m over land. Georeferencing algorithms were developed in-house and earth-referenced data are available several hours after acquisition. Surveys from the system are compared with ground DGPS surveys and existing airborne surveys of fixed targets. Twelve research flights in a Piper Twin Comanche from August 2007 to July 2008 have provided topography of the Southern California coastline and sea surface wave fields in the nearshore ocean environment. Two of the flights also documented the results of the October 2007 landslide on Mt.~Soledad in La Jolla, California. Eight research flights aboard a Cessna Caravan surveyed the topography, lagoon, reef, and surrounding seas of Lady Elliot Island (LEI) in Australia's Great Barrier Reef in April 2008. We describe applications for the system, including coastal topographic surveys, wave measurements, reef research, and ship wake studies.

  8. Initial evaluation of airborne water vapour measurements by the IAGOS-GHG CRDS system

    NASA Astrophysics Data System (ADS)

    Filges, Annette; Gerbig, Christoph; Smit, Herman G. J.; Krämer, Martina; Spelten, Nicole

    2013-04-01

    Accurate and reliable airborne measurements of water vapour are still a challenge. Presently, no airborne humidity sensor exists that covers the entire range of water vapour content between the surface and the upper troposphere/lower stratosphere (UT/LS) region with sufficient accuracy and time resolution. Nevertheless , these data are a pre-requisite to study the underlying processes in the chemistry and physics of the atmosphere. The DENCHAR project (Development and Evaluation of Novel Compact Hygrometer for Airborne Research) addresses this deficit by developing and characterizing novel or improved compact airborne hygrometers for different airborne applications within EUFAR (European Facility for Airborne Research). As part of the DENCHAR inter-comparison campaign in Hohn (Germany), 23 May - 1 June 2011, a commercial gas analyzer (G2401-m, Picarro Inc.,US), based on cavity ring-down spectroscopy (CRDS), was installed on a Learjet to measure water vapour, CO2, CH4 and CO. The CRDS components are identical to those chosen for integration aboard commercial airliner within IAGOS (In-service Aircraft for a Global Observing System). Thus the campaign allowed for the initial assessment validation of the long-term IAGOS H2O measurements by CRDS against reference instruments with a long performance record (FISH, the Fast In-situ Stratospheric Hygrometer, and CR2 frostpoint hygrometer, both research centre Juelich). The inlet system, a one meter long 1/8" FEP-tube connected to a Rosemount TAT housing (model 102BX, deiced) installed on a window plate of the aircraft, was designed to eliminate sampling of larger aerosols, ice particles, and water droplets, and provides about 90% of ram-pressure. In combination with a lowered sample flow of 0.1 slpm (corresponding to a 4 second response time), this ensured a fully controlled sample pressure in the cavity of 140 torr throughout an aircraft altitude operating range up to 12.5 km without the need of an upstream sampling pump

  9. An airborne FLIR detection and warning system for low altitude wind shear

    NASA Technical Reports Server (NTRS)

    Sinclair, Peter C.; Kuhn, Peter M.

    1991-01-01

    It is shown through some preliminary flight measurement research that a forward looking infrared radiometer (FLIR) system can be used to successfully detect the cool downdraft of downbursts (microbusts/macrobursts) and thunderstorm gust front outflows that are responsible for most of the low altitude wind shear (LAWS) events. The FLIR system provides a much greater safety margin for the pilot than that provided by reactive designs such as inertial air speed systems. Preliminary results indicate that an advanced airborne FLIR system could provide the pilot with remote indication of microburst (MB) hazards along the flight path ahead of the aircraft. Results of a flight test of a prototype FLIR system show that a minimum warning time of one to four minutes (5 to 10 km), depending on aircraft speed, is available to the pilot prior to the microburst encounter.

  10. Rotorcraft aircrew systems concepts airborne laboratory (RASCAL) helmet-mounted display flight research

    NASA Astrophysics Data System (ADS)

    Hindson, William S.; Njaka, Chima E.; Aiken, Edwin W.; Barnhart, Warren A.

    1994-06-01

    The Rotorcraft Aircrew Systems Concepts Airborne Laboratory (RASCAL) is a UH-60A Black Hawk helicopter that is being modified by the US Army and NASA for flight systems research. One of the objectives of the research is to develop and integrate technologies for Automated Nap-of-the Earth (ANOE) flight. The principal elements of this system include video imaging sensors, advanced real-time image processing capabilities, a graphics supercomputer, a wide field-of-view color helmet mounted display (HMD), and an advanced fly-by-wire flight control system. The development methodology and the current status of the ANOE Flight Program are summarized, a description of the visionics system is provided, and the plans for the initial applications of the color HMD are presented.

  11. Laser-jamming effectiveness analysis of combined-fiber lasers for airborne defense systems.

    PubMed

    Jie, Xu; Shanghong, Zhao; Rui, Hou; Shengbao, Zhan; Lei, Shi; Jili, Wu; Shaoqiang, Fang; Yongjun, Li

    2008-12-20

    The laser-jamming effectiveness of combined fiber lasers for airborne defense systems is analyzed in detail. Our preliminary experimental results are proof of the concept of getting a high-power laser through a beam combination technique. Based on combined fiber lasers, the jamming effectiveness of four-quadrant guidance and imaging guidance systems are evaluated. The simulation results have proved that for a four-quadrant guidance system, the tracking system takes only two seconds to complete tracking, and the new tracking target is the jamming laser; for the imaging guidance system, increasing the power of the jamming laser or the distance between the target and the jamming laser are both efficient ways to achieve a successful laser jamming.

  12. Airborne Digital Sensor System and GPS-aided inertial technology for direct geopositioning in rough terrain

    USGS Publications Warehouse

    Sanchez, Richard D.

    2004-01-01

    High-resolution airborne digital cameras with onboard data collection based on the Global Positioning System (GPS) and inertial navigation systems (INS) technology may offer a real-time means to gather accurate topographic map information by reducing ground control and eliminating aerial triangulation. Past evaluations of this integrated system over relatively flat terrain have proven successful. The author uses Emerge Digital Sensor System (DSS) combined with Applanix Corporation?s Position and Orientation Solutions for Direct Georeferencing to examine the positional mapping accuracy in rough terrain. The positional accuracy documented in this study did not meet large-scale mapping requirements owing to an apparent system mechanical failure. Nonetheless, the findings yield important information on a new approach for mapping in Antarctica and other remote or inaccessible areas of the world.

  13. Geological applications of multipolarization SAR data

    NASA Technical Reports Server (NTRS)

    Evans, Diane L.

    1986-01-01

    Spaceborne Synthetic Aperture Radar (SAR) data acquired by SEASAT and the Shuttle Imaging Radar (SIR-A/B) operating at L-band with HH polarization were found to be useful in conjunction with other sensors for lithologic discrimination in arid environments with limited vegetation cover. In order to assess the utility of more advanced sensors for geologic research and define the unique contributions each sensor makes, remote sensing data were collected over the Deadman Butte area of the Wind River Basin, Wyoming. The Wind River Basin is an asymmetric sedimentary basin in central Wyoming created during the early Eocene Laramide orogeny. The stratigraphic section of the Deadman Butte study area, which was measured by Woodward is made up of Paleozoic and Mesozoic marine shales, siltstones, limestones, and sandstones. Sensor systems included LANDSAT 4 Thematic Mapper (TM), Thermal Infrared Multispectral Scanner (TIMS) and the Multipolarization, L-band airborne SAR, a prototype for the next Shuttle Imaging Radar (SIR-C). Sensor parameters are given.

  14. 5. SWITCH TOWER AND JUNCTION OF S.A.R. #1 & S.A.R. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    5. SWITCH TOWER AND JUNCTION OF S.A.R. #1 & S.A.R. #2 TRANSMISSION LINES, MARCH 7, 1916. SCE drawing no. 4932. - Santa Ana River Hydroelectric System, Transmission Lines, Redlands, San Bernardino County, CA

  15. An integrated GPS-FID system for airborne gas detection of pipeline right-of-ways

    SciTech Connect

    Gehue, H.L.; Sommer, P.

    1996-12-31

    Pipeline integrity, safety and environmental concerns are of prime importance in the Canadian natural gas industry. Terramatic Technology Inc. (TTI) has developed an integrated GPS/FID gas detection system known as TTI-AirTrac{trademark} for use in airborne gas detection (AGD) along pipeline right-of-ways. The Flame Ionization Detector (FID), which has traditionally been used to monitor air quality for gas plants and refineries, has been integrated with the Global Positioning System (GPS) via a 486 DX2-50 computer and specialized open architecture data acquisition software. The purpose of this technology marriage is to be able to continuously monitor air quality during airborne pipeline inspection. Event tagging from visual surveillance is used to determine an explanation of any delta line deviations (DLD). These deviations are an indication of hydrocarbon gases present in the plume that the aircraft has passed through. The role of the GPS system is to provide mapping information and coordinate data for ground inspections. The ground based inspection using a handheld multi gas detector will confirm whether or not a leak exists.

  16. Assessment of a non-dedicated GPS receiver system for precise airborne attitude determination

    SciTech Connect

    Cannon, M.E.; Sun, H.; Owen, T.E.; Meindl, M.A.

    1994-09-01

    The use of a non-dedicated GPS receiver system for attitude determination was assessed in airborne mode through a test conducted at Sandia National Laboratories. Four independent NovAtel GPSCard{trademark} receivers were installed in Sandia`s Twin Engine Otter with two antennas mounted on the fuselage and two on the wing tips at separations of 6 to 18 m. A strapdown INS was also on board the aircraft in order to provide an independent attitude reference at rates between 4 and 10 Hz. During the multi-day test, GPS measurements were recorded between 1 and 10 Hz. Carrier phase measurements were post-processed using a double difference approach developed at The University of Calgary in which integer ambiguities were resolved in seconds using the known antenna separations as constraints. The tracking capability of the system is demonstrated under dynamics consisting of roll and pitch angles up to 45 and 12 degrees, respectively. Comparisons between the GPS and INS attitude angles are presented for two of the test days and show agreement at the several arcminute level. Conclusions are made with respect to system accuracy and performance in an operational airborne environment.

  17. A Modular and Configurable Instrument Electronics Architecture for "MiniSAR"- An Advanced Smallsat SAR Instrument

    NASA Astrophysics Data System (ADS)

    Gomez, Jaime; Pastena, Max; Bierens, Laurens

    2013-08-01

    MiniSAR is a Dutch program focused on the development of a commercial smallsat featuring a SAR instrument, led by SSBV as prime contractor. In this paper an Instrument Electronics (IEL) system concept to meet the MiniSAR demands is presented. This system has several specificities wrt similar initiatives in the European space industry, driven by our main requirement: keep it small.

  18. Use of airborne and terrestrial lidar to detect ground displacement hazards to water systems

    USGS Publications Warehouse

    Stewart, J.P.; Hu, Jiawen; Kayen, R.E.; Lembo, A.J.; Collins, B.D.; Davis, C.A.; O'Rourke, T. D.

    2009-01-01

    We investigate the use of multiepoch airborne and terrestrial lidar to detect and measure ground displacements of sufficient magnitude to damage buried pipelines and other water system facilities that might result, for example, from earthquake or rainfall-induced landslides. Lidar scans are performed at three sites with coincident measurements by total station surveying. Relative horizontal accuracy is evaluated by measurements of lateral dimensions of well defined objects such as buildings and tanks; we find misfits ranging from approximately 5 to 12 cm, which is consistent with previous work. The bias and dispersion of lidar elevation measurements, relative to total station surveying, is assessed at two sites: (1) a power plant site (PP2) with vegetated steeply sloping terrain; and (2) a relatively flat and unvegetated site before and after trenching operations were performed. At PP2, airborne lidar showed minimal elevation bias and a standard deviation of approximately 70 cm, whereas terrestrial lidar did not produce useful results due to beam divergence issues and inadequate sampling of the study region. At the trench site, airborne lidar showed minimal elevation bias and reduced standard deviation relative to PP2 (6-20 cm), whereas terrestrial lidar was nearly unbiased with very low dispersion (4-6 cm). Pre- and posttrench bias-adjusted normalized residuals showed minimal to negligible correlation, but elevation change was affected by relative bias between epochs. The mean of elevation change bias essentially matches the difference in means of pre- and posttrench elevation bias, whereas elevation change standard deviation is sensitive to the dispersion of individual epoch elevations and their correlation coefficient. The observed lidar bias and standard deviations enable reliable detection of damaging ground displacements for some pipelines types (e.g., welded steel) but not all (e.g., concrete with unwelded, mortared joints). ?? ASCE 2009.

  19. Development and test of video systems for airborne surveillance of oil spills

    NASA Technical Reports Server (NTRS)

    Millard, J. P.; Arvesen, J. C.; Lewis, P. L.

    1975-01-01

    Five video systems - potentially useful for airborne surveillance of oil spills - were developed, flight tested, and evaluated. The systems are: (1) conventional black and white TV, (2) conventional TV with false color, (3) differential TV, (4) prototype Lunar Surface TV, and (5) field sequential TV. Wavelength and polarization filtering were utilized in all systems. Greatly enhanced detection of oil spills, relative to that possible with the unaided eye, was achieved. The most practical video system is a conventional TV camera with silicon-diode-array image tube, filtered with a Corning 7-54 filter and a polarizer oriented with its principal axis in the horizontal direction. Best contrast between oil and water was achieved when winds and sea states were low. The minimum detectable oil film thickness was about 0.1 micrometer.

  20. The development of an airborne instrumentation computer system for flight test

    NASA Technical Reports Server (NTRS)

    Bever, G. A.

    1984-01-01

    Instrumentation interfacing frequently requires the linking of intelligent systems together, as well as requiring the link itself to be intelligent. The airborne instrumentation computer system (AICS) was developed to address this requirement. Its small size, approximately 254 by 133 by 140 mm (10 by 51/4 by 51/2 in), standard bus, and modular board configuration give it the ability to solve instrumentation interfacing and computation problems without forcing a redesign of the entire unit. This system has been used on the F-15 aircraft digital electronic engine control (DEEC) and its follow on engine model derivative (EMD) project and in an OV-1C Mohawk aircraft stall speed warning system. The AICS is presently undergoing configuration for use on an F-104 pace aircraft and on the advanced fighter technology integration (AFTI) F-111 aircraft.

  1. Sampling for Airborne Radioactivity

    DTIC Science & Technology

    2007-10-01

    compared to betas, gammas and neutrons. For an airborne radioactivity detection system, it is most important to be able to detect alpha particles and... Airborne radioactive particles may emit alpha, beta, gamma or neutron radiation, depending on which radioisotope is present. From a health perspective...

  2. A hardware/software simulation for the video tracking system of the Kuiper Airborne Observatory telescope

    NASA Technical Reports Server (NTRS)

    Boozer, G. A.; Mckibbin, D. D.; Haas, M. R.; Erickson, E. F.

    1984-01-01

    This simulator was created so that C-141 Kuiper Airborne Observatory investigators could test their Airborne Data Acquisition and Management System software on a system which is generally more accessible than the ADAMS on the plane. An investigator can currently test most of his data acquisition program using the data computer simulator in the Cave. (The Cave refers to the ground-based computer facilities for the KAO and the associated support personnel.) The main Cave computer is interfaced to the data computer simulator in order to simulate the data-Exec computer communications. However until now, there has been no way to test the data computer interface to the tracker. The simulator described here simulates both the KAO Exec and tracker computers with software which runs on the same Hewlett-Packard (HP) computer as the investigator's data acquisition program. A simulator control box is hardwired to the computer to provide monitoring of tracker functions, to provide an operator panel similar to the real tracker, and to simulate the 180 deg phase shifting of the chopper squre-wave reference with beam switching. If run in the Cave, one can use their Exec simulator and this tracker simulator.

  3. Imaging of buried and foliage-obscured objects with an ultrawide-bandwidth polarimetric SAR

    NASA Astrophysics Data System (ADS)

    Sheen, Dan R.; Lewis, Terry B.; Wei, Susan C.; Kletzli, D. W., Jr.

    1993-11-01

    The Environmental Research Institute of Michigan (ERIM) has developed a unique ground- based, portable, synthetic aperture radar (SAR). This SAR images targets in their natural backgrounds without the expense of an airborne sensor and with higher performance (bandwidth, resolution) than existing airborne systems. A horizontal 36-foot long aluminum truss supports a rail and an antenna cartridge, which is moved along the rail to allow synthetic aperture focusing. The system is fully-polarimetric and has collected data over the frequency band of 400 - 1300 MHz resulting in a nominal resolution of 0.17 m in range and 0.5 m in cross-range. The low frequency range of the system allows for penetration of soil (to shallow depths) as well as foliage and the system has been used to collect images of buried and foliage- obscured targets. The ground imagery collected to date includes steel oil drums buried at depths of up to one-meter. Both the drums as well as the disturbances due to digging the holes are visible in the imagery. Foliage imagery includes portions of a Lear jet under a mature hardwood forest. Due to the low frequency and wide bandwidth of the sensor (400 - 1300 MHz), obscured objects are clearly visible in the SAR imagery. Other responses in the foliage imagery are due to the dihedral-like ground-trunk reflections.

  4. SITHON: An Airborne Fire Detection System Compliant with Operational Tactical Requirements

    PubMed Central

    Kontoes, Charalabos; Keramitsoglou, Iphigenia; Sifakis, Nicolaos; Konstantinidis, Pavlos

    2009-01-01

    In response to the urging need of fire managers for timely information on fire location and extent, the SITHON system was developed. SITHON is a fully digital thermal imaging system, integrating INS/GPS and a digital camera, designed to provide timely positioned and projected thermal images and video data streams rapidly integrated in the GIS operated by Crisis Control Centres. This article presents in detail the hardware and software components of SITHON, and demonstrates the first encouraging results of test flights over the Sithonia Peninsula in Northern Greece. It is envisaged that the SITHON system will be soon operated onboard various airborne platforms including fire brigade airplanes and helicopters as well as on UAV platforms owned and operated by the Greek Air Forces. PMID:22399963

  5. Soil moisture retrieval through a merging of multi-temporal L-band SAR data and hydrologic modelling

    NASA Astrophysics Data System (ADS)

    Mattia, F.; Satalino, G.; Pauwels, V. R. N.; Loew, A.

    2009-03-01

    The objective of the study is to investigate the potential of retrieving superficial soil moisture content (mv) from multi-temporal L-band synthetic aperture radar (SAR) data and hydrologic modelling. The study focuses on assessing the performances of an L-band SAR retrieval algorithm intended for agricultural areas and for watershed spatial scales (e.g. from 100 to 10 000 km2). The algorithm transforms temporal series of L-band SAR data into soil moisture contents by using a constrained minimization technique integrating a priori information on soil parameters. The rationale of the approach consists of exploiting soil moisture predictions, obtained at coarse spatial resolution (e.g. 15-30 km2) by point scale hydrologic models (or by simplified estimators), as a priori information for the SAR retrieval algorithm that provides soil moisture maps at high spatial resolution (e.g. 0.01 km2). In the present form, the retrieval algorithm applies to cereal fields and has been assessed on simulated and experimental data. The latter were acquired by the airborne E-SAR system during the AgriSAR campaign carried out over the Demmin site (Northern Germany) in 2006. Results indicate that the retrieval algorithm always improves the a priori information on soil moisture content though the improvement may be marginal when the accuracy of prior mv estimates is better than 5%.

  6. Soil moisture retrieval through a merging of multi-temporal L-band SAR data and hydrologic modelling

    NASA Astrophysics Data System (ADS)

    Mattia, F.; Satalino, G.; Pauwels, V. R. N.; Loew, A.

    2008-12-01

    The objective of the study is to investigate the potential of retrieving superficial soil moisture content (mv) from multi-temporal L-band synthetic aperture radar (SAR) data and hydrologic modelling. The study focuses on assessing the performances of an L-band SAR retrieval algorithm intended for agricultural areas and for watershed spatial scales (e.g. from 100 to 10 000 km2). The algorithm transforms temporal series of L-band SAR data into soil moisture contents by using a constrained minimization technique integrating a priori information on soil parameters. The rationale of the approach consists of exploiting soil moisture predictions, obtained at coarse spatial resolution (e.g. 15-30 km2) by point scale hydrologic models (or by simplified estimators), as a priori information for the SAR retrieval algorithm that provides soil moisture maps at high spatial resolution (e.g. 0.01 km2). In the present form, the retrieval algorithm applies to cereal fields and has been assessed on simulated and experimental data. The latter were acquired by the airborne E-SAR system during the AgriSAR campaign carried out over the Demmin site (Northern Germany) in 2006. Results indicate that the retrieval algorithm always improves the a priori information on soil moisture content though the improvement may be marginal when the accuracy of prior mv estimates is better than 5%.

  7. Geophex Airborne Unmanned Survey System (GAUSS). Topical report, October 1993--September 1996

    SciTech Connect

    1998-12-31

    This document is a Final Technical Report that describes the results of the Geophex Airborne Unmanned Survey System (GAUSS) research project. The objectives were to construct a geophysical data acquisition system that uses a remotely operated unmanned aerial vehicle (UAV) and to evaluate its effectiveness for characterization of hazardous environmental sites. The GAUSS is a data acquisition system that mitigates the potential risk to personnel during geophysical characterization of hazardous or radioactive sites. The fundamental basis of the GAUSS is as follows: (1) an unmanned survey vehicle carries geophysical sensors into a hazardous location, (2) the pilot remains outside the hazardous site and operates the vehicle using radio control, (3) geophysical measurements and their spatial locations are processed by an automated data-acquisition system which displays data on an off-site monitor in real-time, and (4) the pilot uses the display to direct the survey vehicle for complete site coverage. The objective of our Phase I research was to develop a data acquisition and processing (DAP) subsystem and geophysical sensors suitable for UAV deployment. We integrated these two subsystems to produce an automated, hand-held geophysical surveying system. The objective of the Phase II effort was to modify the subsystems and integrate them into an airborne prototype. The completed GAUSS DAP system consists of a UAV platform, a laser tracking and ranging subsystem, a telemetry subsystem, light-weight geophysical sensors, a base-station computer (BC), and custom-written survey control software (SCS). We have utilized off-the-shelf commercial products, where possible, to reduce cost and design time.

  8. High resolution multisensor fusion of SAR, optical and LiDAR data based on crisp vs. fuzzy and feature vs. decision ensemble systems

    NASA Astrophysics Data System (ADS)

    Bigdeli, Behnaz; Pahlavani, Parham

    2016-10-01

    Synthetic Aperture Radar (SAR) data are of high interest for different applications in remote sensing specially land cover classification. SAR imaging is independent of solar illumination and weather conditions. It can even penetrate some of the Earth's surface materials to return information about subsurface features. However, the response of radar is more a function of geometry and structure than a surface reflection occurs in optical images. In addition, the backscatter of objects in the microwave range depends on the frequency of the band used, and the grey values in SAR images are different from the usual assumption of the spectral reflectance of the Earth's surface. Consequently, SAR imaging is often used as a complementary technique to traditional optical remote sensing. This study presents different ensemble systems for multisensor fusion of SAR, multispectral and LiDAR data. First, in decision ensemble system, after extraction and selection of proper features from each data, crisp SVM (Support Vector Machine) and Fuzzy KNN (K Nearest Neighbor) are utilized on each feature space. Finally Bayesian Theory is applied to fuse SVMs when Decision Template (DT) and Dempster Shafer (DS) are applied as fuzzy decision fusion methods on KNNs. Second, in feature ensemble system, features from all data are applied on a cube. Then classifications were performed by SVM and FKNN as crisp and fuzzy decision making system respectively. A co-registered TerrraSAR-X, WorldView-2 and LiDAR data set form San Francisco of USA was available to examine the effectiveness of the proposed method. The results show that combinations of SAR data with different sensor improves classification results for most of the classes.

  9. Performance of the NASA Airborne Radar with the Windshear Database for Forward-Looking Systems

    NASA Technical Reports Server (NTRS)

    Switzer, George F.; Britt, Charles L.

    1996-01-01

    This document describes the simulation approach used to test the performance of the NASA airborne windshear radar. An explanation of the actual radar hardware and processing algorithms provides an understanding of the parameters used in the simulation program. This report also contains a brief overview of the NASA airborne windshear radar experimental flight test results. A description of the radar simulation program shows the capabilities of the program and the techniques used for certification evaluation. Simulation of the NASA radar is comprised of three steps. First, the choice of the ground clutter data must be made. The ground clutter is the return from objects in or nearby an airport facility. The choice of the ground clutter also dictates the aircraft flight path since ground clutter is gathered while in flight. The second step is the choice of the radar parameters and the running of the simulation program which properly combines the ground clutter data with simulated windshear weather data. The simulated windshear weather data is comprised of a number of Terminal Area Simulation System (TASS) model results. The final step is the comparison of the radar simulation results to the known windshear data base. The final evaluation of the radar simulation is based on the ability to detect hazardous windshear with the aircraft at a safe distance while at the same time not displaying false alerts.

  10. Demonstration of a hermetic airborne ozone disinfection system: studies on E. coli.

    PubMed

    Kowalski, W J; Bahnfleth, W P; Striebig, B A; Whittam, T S

    2003-01-01

    An enclosed flow-through system using airborne ozone for disinfection and which removes the ozone with a catalytic converter was tested with a strain of Escherichia coli. Petri dishes containing the microorganisms were inserted in a chamber and exposed for 10-480 min to ozone concentrations between 4 and 20 ppm. Death rates in excess of 99.99% were achieved. Survival data is fitted to a two-stage curve with a shoulder based on the multihit target model. Ozone was removed from the exhaust air to nondetectable levels using a metal oxide based catalyst. The possibility of using ozone as an airborne disinfectant for internal building surfaces and catalytically removing the ozone on exhaust is demonstrated to be feasible. A model for the decay of Bacillus cereus under ozone exposure is proposed as an example for predicting the sterilization of buildings contaminated with anthrax. The potential for disinfecting airstreams and removing ozone to create breathable air is also implied by the results of this experiment.

  11. Long-Term Tracking of a Specific Vehicle Using Airborne Optical Camera Systems

    NASA Astrophysics Data System (ADS)

    Kurz, F.; Rosenbaum, D.; Runge, H.; Cerra, D.; Mattyus, G.; Reinartz, P.

    2016-06-01

    In this paper we present two low cost, airborne sensor systems capable of long-term vehicle tracking. Based on the properties of the sensors, a method for automatic real-time, long-term tracking of individual vehicles is presented. This combines the detection and tracking of the vehicle in low frame rate image sequences and applies the lagged Cell Transmission Model (CTM) to handle longer tracking outages occurring in complex traffic situations, e.g. tunnels. The CTM model uses the traffic conditions in the proximities of the target vehicle and estimates its motion to predict the position where it reappears. The method is validated on an airborne image sequence acquired from a helicopter. Several reference vehicles are tracked within a range of 500m in a complex urban traffic situation. An artificial tracking outage of 240m is simulated, which is handled by the CTM. For this, all the vehicles in the close proximity are automatically detected and tracked to estimate the basic density-flow relations of the CTM model. Finally, the real and simulated trajectories of the reference vehicles in the outage are compared showing good correspondence also in congested traffic situations.

  12. Interoperable Data Systems for Satellite, Airborne, and Terrestrial LiDAR Data

    NASA Astrophysics Data System (ADS)

    Meertens, C. M.; Baru, C.; Blair, B.; Crosby, C. J.; Haran, T. M.; Harding, D. J.; Hofton, M. A.; Khalsa, S. S.; McWhirter, J.

    2010-12-01

    LiDAR (Light Detection and Ranging) technology is being widely applied to scientific problems on global to local scales using a range of laser technologies mounted on satellite, low- and high-altitude airborne and terrestrial platforms. Modern laser ranging instruments are increasingly capable of providing full waveform data, multiple detectors, higher sample rates and longer ranges. Accompanying these improvements, however, are rapidly growing data volumes and ever more complex data formats and processing algorithms. This presents significant challenges for existing Earth science data systems serving these data and creates barriers to the efficient use of these data by a growing and diverse community of scientific and other users who are studying deformation of the solid Earth, the cryosphere, vegetation structure, and land form evolution. To address these challenges, a group of data centers is collaborating under a project funded by the NASA ROSES ACCESS Program to develop interoperable LiDAR data access systems to provide integrated access to data and derived products in common data formats via simple-to-navigate web interfaces. The web service-based systems created by this project, called NLAS, will enhance access to existing laser data sources hosted at the National Snow and Ice Data Center DAAC, Goddard Space Flight Center LVIS Data Center, UNAVCO, and the OpenTopography Facility at the San Diego Supercomputer Center (SDSC). Through the OpenTopography portal, NLAS systems will provide access to satellite laser altimetry data from ICESat and high altitude airborne laser scanning data from LVIS, as well as low altitude airborne LiDAR and terrestrial laser scanning data hosted at OpenTopography and UNAVCO. NLAS will develop new web service interfaces for NASA data archives at GSFC/LVIS and NSIDC in an effort to improve and streamline access to these data archives. The OpenTopography portal will act as a client to the NLAS services and will provide integrated

  13. Development and Evaluation of an Airborne Superconducting Quantum Interference Device-Based Magnetic Gradiometer Tensor System for Detection, Characterization and Mapping of Unexploded Ordnance

    DTIC Science & Technology

    2008-08-01

    FINAL REPORT Development and Evaluation of an Airborne Superconducting Quantum Interference Device-Based Magnetic Gradiometer Tensor System...Airborne Superconducting Quantum Interference Device-Based Magnetic Gradiometer Tensor System for Detection, Characterization and Mapping of Unexploded...Demonstration of the difference between a single component total field magnetometer and intrinsic gradiometer . (From Clarke, 1994). 4 Figure 3

  14. An efficient two-objective automatic SAR image segmentation framework using artificial immune system

    NASA Astrophysics Data System (ADS)

    Yang, Dongdong; Niu, Ruican; Fei, Rong; Jiang, Qiaoyong; Li, Hongye; Cao, Zijian

    2015-12-01

    Here, an efficient multi-objective automatic segmentation framework (MASF) is formulated and applied to synthetic aperture radar (SAR) image unsupervised classification. In the framework, three important issues are presented: 1) two reasonable image preprocessing techniques, including spatial filtering and watershed operator, are discussed at the initial stage of the framework; 2)then, an efficient immune multi-objective optimization algorithm with uniform clone, adaptive selection by online nondominated solutions, and dynamic deletion in diversity maintenance is proposed; 3 two very simple, but very efficient conflicting clustering validity indices are incorporated into the framework and simultaneously optimized. Two simulated SAR data and two complicated real images are used to quantitatively validate its effectiveness. In addition, four other state-of-the-art image segmentation methods are employed for comparison.

  15. A pattern recognition system for locating small volvanoes in Magellan SAR images of Venus

    NASA Technical Reports Server (NTRS)

    Burl, M. C.; Fayyad, U. M.; Smyth, P.; Aubele, J. C.; Crumpler, L. S.

    1993-01-01

    The Magellan data set constitutes an example of the large volumes of data that today's instruments can collect, providing more detail of Venus than was previously available from Pioneer Venus, Venera 15/16, or ground-based radar observations put together. However, data analysis technology has not kept pace with data collection and storage technology. Due to the sheer size of the data, complete and comprehensive scientific analysis of such large volumes of image data is no longer feasible without the use of computational aids. Our progress towards developing a pattern recognition system for aiding in the detection and cataloging of small-scale natural features in large collections of images is reported. Combining classical image processing, machine learning, and a graphical user interface, the detection of the 'small-shield' volcanoes (less than 15km in diameter) that constitute the most abundant visible geologic feature in the more that 30,000 synthetic aperture radar (SAR) images of the surface of Venus are initially targeted. Our eventual goal is to provide a general, trainable tool for locating small-scale features where scientists specify what to look for simply by providing examples and attributes of interest to measure. This contrasts with the traditional approach of developing problem specific programs for detecting Specific patterns. The approach and initial results in the specific context of locating small volcanoes is reported. It is estimated, based on extrapolating from previous studies and knowledge of the underlying geologic processes, that there should be on the order of 10(exp 5) to 10(exp 6) of these volcanoes visible in the Magellan data. Identifying and studying these volcanoes is fundamental to a proper understanding of the geologic evolution of Venus. However, locating and parameterizing them in a manual manner is forbiddingly time-consuming. Hence, the development of techniques to partially automate this task were undertaken. The primary

  16. Pol(In)SAR Soil Moisture Study by using Pi-SAR 2L and GB-SAR Data in Preparation of the upcoming ALOS-2/PALSAR-2 Mission

    NASA Astrophysics Data System (ADS)

    Koyama, C.; Sato, M.

    2013-12-01

    moving along a rail to provide the scanning. This is the first time that such a study is carried out. Up to now the radar skin depth of natural terrain with varying soil water content is usually somewhat ill-defined. Moreover, super high resolution airborne fully polarimetric L-band SAR data from repeat-pass as well as from square-flight acquisitions is used to demonstrate the potentials of surface parameter retrieval from PolInSAR and multi-angular PolSAR data. The Pi-SAR 2L operated by JAXA is the same system which is used for the pre-launch Cal/Val operations for PALSAR-2. Based on recent campaign data acquired over our test sites in the Sendai area, we demonstrate the potential of the upcoming ALOS-2/PALSAR-2 for frequent global-wide soil moisture and vegetation biomass observation.

  17. Spacecraft on-board SAR processing technology

    NASA Technical Reports Server (NTRS)

    Liu, K. Y.; Arens, W. E.

    1987-01-01

    This paper provides an assessment of the on-board SAR processing technology for Eos-type missions. The proposed Eos SAR sensor and flight data system are introduced, and the SAR processing requirements are described. The SAR on-board SAR processor architecture selection is discussed, and a baseline processor architecture using a frequency-domain processor for range correlation and a modular fault-tolerant VLSI time-domain parallel array for azimuth correlation are described. The mass storage and VLSI technologies needed for implementing the proposed SAR processing are assessed. It is shown that acceptable processor power and mass characteristics should be feasible for Eos-type applications. A proposed development strategy for the on-board SAR processor is presented.

  18. Optimized Design of the SGA-WZ Strapdown Airborne Gravimeter Temperature Control System

    PubMed Central

    Cao, Juliang; Wang, Minghao; Cai, Shaokun; Zhang, Kaidong; Cong, Danni; Wu, Meiping

    2015-01-01

    The temperature control system is one of the most important subsystems of the strapdown airborne gravimeter. Because the quartz flexible accelerometer based on springy support technology is the core sensor in the strapdown airborne gravimeter and the magnet steel in the electromagnetic force equilibrium circuits of the quartz flexible accelerometer is greatly affected by temperature, in order to guarantee the temperature control precision and minimize the effect of temperature on the gravimeter, the SGA-WZ temperature control system adopts a three-level control method. Based on the design experience of the SGA-WZ-01, the SGA-WZ-02 temperature control system came out with a further optimized design. In 1st level temperature control, thermoelectric cooler is used to conquer temperature change caused by hot weather. The experiments show that the optimized stability of 1st level temperature control is about 0.1 °C and the max cool down capability is about 10 °C. The temperature field is analyzed in the 2nd and 3rd level temperature control using the finite element analysis software ANSYS. The 2nd and 3rd level temperature control optimization scheme is based on the foundation of heat analysis. The experimental results show that static accuracy of SGA-WZ-02 reaches 0.21 mGal/24 h, with internal accuracy being 0.743 mGal/4.8 km and external accuracy being 0.37 mGal/4.8 km compared with the result of the GT-2A, whose internal precision is superior to 1 mGal/4.8 km and all of them are better than those in SGA-WZ-01. PMID:26633407

  19. Optimized Design of the SGA-WZ Strapdown Airborne Gravimeter Temperature Control System.

    PubMed

    Cao, Juliang; Wang, Minghao; Cai, Shaokun; Zhang, Kaidong; Cong, Danni; Wu, Meiping

    2015-12-01

    The temperature control system is one of the most important subsystems of the strapdown airborne gravimeter. Because the quartz flexible accelerometer based on springy support technology is the core sensor in the strapdown airborne gravimeter and the magnet steel in the electromagnetic force equilibrium circuits of the quartz flexible accelerometer is greatly affected by temperature, in order to guarantee the temperature control precision and minimize the effect of temperature on the gravimeter, the SGA-WZ temperature control system adopts a three-level control method. Based on the design experience of the SGA-WZ-01, the SGA-WZ-02 temperature control system came out with a further optimized design. In 1st level temperature control, thermoelectric cooler is used to conquer temperature change caused by hot weather. The experiments show that the optimized stability of 1st level temperature control is about 0.1 °C and the max cool down capability is about 10 °C. The temperature field is analyzed in the 2nd and 3rd level temperature control using the finite element analysis software ANSYS. The 2nd and 3rd level temperature control optimization scheme is based on the foundation of heat analysis. The experimental results show that static accuracy of SGA-WZ-02 reaches 0.21 mGal/24 h, with internal accuracy being 0.743 mGal/4.8 km and external accuracy being 0.37 mGal/4.8 km compared with the result of the GT-2A, whose internal precision is superior to 1 mGal/4.8 km and all of them are better than those in SGA-WZ-01.

  20. Statistical model for atmospheric limb radiance structure: application to airborne infrared surveillance systems

    NASA Astrophysics Data System (ADS)

    Quang, Carine; Dalaudier, Francis; Roblin, Antoine; Rialland, Valérie; Chervet, Patrick

    2008-10-01

    Infrared (IR) detectors can be used as airborne limb-viewing surveillance systems for missile detection. These systems' performances are impacted by the atmospheric inhomogeneous background. In fact, the probability of target detection can be heavily affected. Consequently, the knowledge of these radiance small-scale fluctuations and their statistical properties is required to assess these systems' detection capability. A model of two-dimensional radiance spatial fluctuations autocorrelation function (ACF) is developed. This model is dedicated to airborne limb-viewing conditions in the thermal IR. In the stratosphere and in clear-sky conditions, the structured background is mainly due to internal-gravity-wave-induced temperature and density spatial fluctuations. Moreover, in the particular case of water vapour absorption bands, the mass fraction fluctuations play a non negligible role on the radiative field. Thereby, considering the temperature field and the water vapour field as stochastic processes, the radiance ACF can be expressed as a function of the temperature ACF and the water vapor mass fraction ACF. A local thermodynamic equilibrium model is sufficient for stratospheric conditions and sunlight scattering is neglected in the thermal IR. In addition, determination of the radiance fluctuations ACF requires the knowledge of the absorption coefficient and its first derivatives with respect to the temperature and water vapour mass fraction. Thus, a line-by-line model specific to water vapor absorption bands has been developed. This model is used to precalculate the absorption coefficients and their derivatives. This look-up table method allows circumventing the computational cost of a line-by-line calculation. A detailed description of the radiance fluctuations ACF model is presented and first results are discussed.

  1. Preliminary analysis results of the Sea Surface Observation by a High Resolution Along-Track Interferometric SAR

    NASA Astrophysics Data System (ADS)

    Kojima, S.

    2013-12-01

    There are many requirements to detect the moving targets such as cars and ships in SAR images as well as to measure their speed. In particular, there are strongly requirements to detect ships and measure the ocean waves and the sea surface currents regardless of the time or the weather in the case of the ship accidents or the oil spill accidents because the rescue operation should be operated at the anytime. To satisfy these requirements, NICT developed the airborne along-track interferometric SAR (AT-InSAR) system in 2011. Kojima[1][2] carried out the preliminary experiments using a truck and ship to check its function and clarify its capability for the detection of the moving targets, and confirmed that its performance was satisfied with its specifications. The purpose of this study is to make clear the relationship between the phenomena on the sea surface such as the ocean waves and the velocity estimated from the AT-InSAR data, and the capability of the sea surface measurement by the AT-InSAR. In addition, the method to estimate wave directional spectra from AT-InSAR data is developed. The sea surface observation was carried out 3 km off the coast of Ooarai, the northeast of Tokyo, JAPAN on the 23th of August 2011. I observed the sea surface in the fine special resolution (0.3 m) and took a special average (1 m) to reduce noise. First of all, I estimated the wave velocity from the AT-InSAR images and calculated the 2D wave number spectra from it. And then, I estimated the directional wave spectra using the dispersion relation. As a result, it was clarified that the ocean waves could be measured by the AT-InSAR. In addition, it made clear that the bow waves and stern waves generated by a running ship could be detected by AT-InSAR. References [1] S. Kojima, T. Umehara, J. Uemoto, T. Kobayashi, M. Satake and S. Uratsuka, 'Development of Pi-SAR2 Along-Track Interferometric SAR System', IGARSS 2013, pp. 3159-3162, Aug. 2013. [2] S. Kojima, 'Evaluation of the Ship

  2. Recursive SAR imaging

    NASA Astrophysics Data System (ADS)

    Moses, Randolph L.; Ash, Joshua N.

    2008-04-01

    We investigate a recursive procedure for synthetic aperture imaging. We consider a concept in which a SAR system persistently interrogates a scene, for example as it flies along or around that scene. In traditional SAR imaging, the radar measurements are processed in blocks, by partitioning the data into a set of non-overlapping or overlapping azimuth angles, then processing each block. We consider a recursive update approach, in which the SAR image is continually updated, as a linear combination of a small number of previous images and a term containing the current radar measurement. We investigate the crossrange sidelobes realized by such an imaging approach. We show that a first-order autoregression of the image gives crossrange sidelobes similar to a rectangular azimuth window, while a third-order autoregression gives sidelobes comparable to those obtained from widely-used windows in block-processing image formation. The computational and memory requirements of the recursive imaging approach are modest - on the order of M • N2 where M is the recursion order (typically <= 3) and N2 is the image size. We compare images obtained from the recursive and block processing techniques, both for a synthetic scene and for X-band SAR measurements from the Gotcha data set.

  3. Performance evaluation of a novel personalized ventilation-personalized exhaust system for airborne infection control.

    PubMed

    Yang, J; Sekhar, S C; Cheong, K W D; Raphael, B

    2015-04-01

    In the context of airborne infection control, it is critical that the ventilation system is able to extract the contaminated exhaled air within the shortest possible time. To minimize the spread of contaminated air exhaled by occupants efficiently, a novel personalized ventilation (PV)-personalized exhaust (PE) system has been developed, which aims to exhaust the exhaled air as much as possible from around the infected person (IP). The PV-PE system was studied experimentally for a particular healthcare setting based on a typical consultation room geometry and four different medical consultation positions of an IP and a healthy person (HP). Experiments using two types of tracer gases were conducted to evaluate two types of PE: Top-PE and Shoulder-PE under two different background ventilation systems: Mixing Ventilation and Displacement Ventilation. Personalized exposure effectiveness, intake fraction (iF) and exposure reduction (ε) were used as indices to evaluate the PV-PE system. The results show that the combined PV-PE system for the HP achieves the lowest intake fraction; and the use of PE system for the IP alone shows much better performance than using PV system for the HP alone.

  4. ERS-1 SAR data processing

    NASA Technical Reports Server (NTRS)

    Leung, K.; Bicknell, T.; Vines, K.

    1986-01-01

    To take full advantage of the synthetic aperature radar (SAR) to be flown on board the European Space Agency's Remote Sensing Satellite (ERS-1) (1989) and the Canadian Radarsat (1990), the implementation of a receiving station in Alaska is being studied to gather and process SAR data pertaining in particular to regions within the station's range of reception. The current SAR data processing requirement is estimated to be on the order of 5 minutes per day. The Interim Digital Sar Processor (IDP) which was under continual development through Seasat (1978) and SIR-B (1984) can process slightly more than 2 minutes of ERS-1 data per day. On the other hand, the Advanced Digital SAR Processore (ADSP), currently under development for the Shuttle Imaging Radar C (SIR-C, 1988) and the Venus Radar Mapper, (VMR, 1988), is capable of processing ERS-1 SAR data at a real time rate. To better suit the anticipated ERS-1 SAR data processing requirement, both a modified IDP and an ADSP derivative are being examined. For the modified IDP, a pipelined architecture is proposed for the mini-computer plus array processor arrangement to improve throughout. For the ADSP derivative, a simplified version is proposed to enhance ease of implementation and maintainability while maintaing real time throughput rates. These processing systems are discussed and evaluated.

  5. Advanced Airborne Hyperspectral Imaging System (AAHIS): an imaging spectrometer for maritime applications

    NASA Astrophysics Data System (ADS)

    Voelker, Mark A.; Resmini, Ronald G.; Mooradian, Gregory C.; McCord, Thomas B.; Warren, Christopher P.; Fene, Michael W.; Coyle, Christopher C.; Anderson, Richard

    1995-06-01

    The Advanced Airborne Hyperspectral Imaging System (AAHIS) is a compact, lightweight visible and near IR pushbroom hyperspectral imaging spectrometer flown on a Piper Aztec aircraft. AAHIS is optimized for use in shallow water, littoral, and vegetation remote sensing. Data are collected at up to 55 frames/second and may be displayed and analyzed inflight or recorded for post-flight processing. Swath width is 200 meters at a flight altitude of 1 km. Each image pixel contains hyperspectral data simultaneously recorded in up to 288 contiguous spectral channels covering the 432 to 832 nm spectral region. Pixel binning typically yields pixels 1.0 meter square with a spectral channel width of 5.5 nm. Design and performance of the AAHIS is presented, including processed imagery demonstrating feature detection and materials discrimination on land and underwater at depths up to 27 meters.

  6. Failure detection of liquid cooled electronics in sealed packages. [in airborne information management system

    NASA Technical Reports Server (NTRS)

    Hoadley, A. W.; Porter, A. J.

    1991-01-01

    The theory and experimental verification of a method of detecting fluid-mass loss, expansion-chamber pressure loss, or excessive vapor build-up in NASA's Airborne Information Management System (AIMS) are presented. The primary purpose of this leak-detection method is to detect the fluid-mass loss before the volume of vapor on the liquid side causes a temperature-critical part to be out of the liquid. The method detects the initial leak after the first 2.5 pct of the liquid mass has been lost, and it can be used for detecting subsequent situations including the leaking of air into the liquid chamber and the subsequent vapor build-up.

  7. Airborne gravity gradiometer surveying of petroleum systems under Lake Tanganyika, Tanzania

    NASA Astrophysics Data System (ADS)

    Roberts, Doug; Chowdhury, Priyanka Roy; Lowe, Sharon Jenny; Christensen, Asbjorn Norlund

    2016-02-01

    The Lake Tanganyika South petroleum exploration block covers the southern portion of the Tanzanian side of Lake Tanganyika and is located within the East African Rift System. The rifting process has formed rotated fault blocks which provide numerous play types in the resulting basins. Interpretation of 2D seismic data from 1984 indicated that sufficient sediment thickness is present for hydrocarbon generation. The prospectivity of the lake sediment sequence is enhanced by large oil discoveries further north along the rift system at Lake Albert in Uganda. Airborne gravity gradiometry (AGG) has been used in the Lake Albert region to delineate the structural framework of sedimentary basins. Based on this analogy, in 2010 Beach Energy commissioned CGG to fly a FALCON AGG and high-resolution airborne magnetic survey over the Lake Tanganyika South block to provide data for mapping the basin architecture and estimating the depth to magnetic basement. A total of nearly 28000 line kilometres of data were acquired. The subsequent interpretation incorporated the AGG and magnetic data with available 2D seismic data, elevation model data, bathymetry, Landsat and regional geology information. The integrated data interpretation revealed that the Lake Tanganyika rifting structures occur as half-grabens that were formed through reactivation of Precambrian fault structures. Two major depocentres were identified in the magnetic depth-to-basement map in the north and in the west-central part of the survey area with sediment thicknesses in excess of 4 km and 3 km, respectively. Smaller, shallower depocentres (with less than 3 km of sediment) occur in the south-western region. This information was used to plan a 2100 km 2D marine seismic survey that was recorded in 2012. An interpretation of the results from the seismic survey confirmed a rifting structure similar to that encountered further north at Lake Albert in Uganda. Several targets were identified from the seismic sections for

  8. Airborne Wind Profiling With the Data Acquisition and Processing System for a Pulsed 2-Micron Coherent Doppler Lidar System

    NASA Technical Reports Server (NTRS)

    Beyon, Jeffrey Y.; Koch, Grady J.; Kavaya, Michael J.

    2012-01-01

    A pulsed 2-micron coherent Doppler lidar system at NASA Langley Research Center in Virginia flew on the NASA's DC-8 aircraft during the NASA Genesis and Rapid Intensification Processes (GRIP) during the summer of 2010. The participation was part of the project Doppler Aerosol Wind Lidar (DAWN) Air. Selected results of airborne wind profiling are presented and compared with the dropsonde data for verification purposes. Panoramic presentations of different wind parameters over a nominal observation time span are also presented for selected GRIP data sets. The realtime data acquisition and analysis software that was employed during the GRIP campaign is introduced with its unique features.

  9. Initial observations on using SAR to monitor wildfire scars in boreal forests

    NASA Technical Reports Server (NTRS)

    Kasischke, E. S.; Bourgeau-Chavez, L. L.; French, N. H. F.; Harrell, P.; Christensen, N. L., Jr.

    1992-01-01

    Initial observations on the effects of wildfires in black spruce forests on radar backscatter are presented. Airborne and spaceborne SAR imagery are utilized to illustrate two distinct fire signatures. A theory is presented to explain these differences.

  10. Interferometric SAR imaging by transmitting stepped frequency chaotic noise signals

    NASA Astrophysics Data System (ADS)

    Zhang, Yunhua; Gu, Xiang; Zhai, Wenshuai; Dong, Xiao; Shi, Xiaojin; Kang, Xueyan

    2015-10-01

    Noise radar has been applied in many fields since it was proposed more than 50 years ago. However, it has not been applied to interferometric SAR imaging yet as far as we know. This paper introduces our recent work on interferometric noise radar. An interferometric SAR system was developed which can transmit both chirp signal and chaotic noise signal (CNS) at multiple carrier frequencies. An airborne experiment with this system by transmitting both signals was carried out, and the data were processed to show the capability of interferometric SAR imaging with CNS. The results shows that although the interferometric phase quality of CNS is degraded due to the signal to noise ratio (SNR) is lower compared with that of chirp signal, we still can get satisfied DEM after multi-looking processing. Another work of this paper is to apply compressed sensing (CS) theory to the interferometric SAR imaging with CNS. The CS theory states that if a signal is sparse, then it can be accurately reconstructed with much less sampled data than that regularly required according to Nyquist Sampling Theory. To form a structured random matrix, if the transmitted signal is of fixed waveform, then random subsampling is needed. However, if the transmitted signal is of random waveform, then only uniform subsampling is needed. This is another advantage of noise signal. Both the interferometric phase images and the DEMs by regular method and by CS method are processed with results compared. It is shown that the degradation of interferometric phases due to subsampling is larger than that of amplitude image.

  11. Volcano deformation analysis based an on-demand DInSAR-GRID system: the SBAS-GPOD solution

    NASA Astrophysics Data System (ADS)

    Manunta, M.; Casu, F.; Cossu, R.; Fusco, L.; Guarino, S.; Lanari, R.; Mazzarella, G.; Sansosti, E.

    2009-04-01

    Differential SAR Interferometry (DInSAR) has already demonstrated to be an effective technique to detect and monitor ground displacements with centimeter accuracy. Moreover, the recent development of advanced DInSAR techniques, aimed at the generation of deformation time series, has led to the exploitation of the large archive of SAR data acquired all over the world, during the last 16 years, by the ERS, ENVISAT and RADARSAT satellites. Among these advanced approaches, we focus on the Small BAseline Subset (SBAS) algorithm that relies on the combination of DInSAR data pairs, characterized by a small separation between the acquisition orbits (baseline), in order to produce mean deformation velocity maps and the corresponding time series, maximizing the coherent pixel density of the investigated area. One of the main capabilities of the SBAS approach is the possibility to work at two spatial resolution scales, thus allowing us to investigate deformation phenomena affecting both extended areas (with resolution of about 100 by 100 m) and selected zones, in the latter case highlighting localized displacements that may affect single structures or buildings (at the full instrument resolution). Similarly to other advanced DInSAR techniques, the SBAS approach requires extended data storage and processing capabilities due to the large amount of data exploited for the generation of the final products. Accordingly, we present in this work the results of the first experiment to "plug" the robustness of the SBAS algorithm into the high computing capability provided by a GRID-based system. In particular, we have exploited the low-resolution SBAS algorithm [1] and the ESA Grid Processing-on-Demand (G-POD) system. This environment is one of the results achieved by the ESA Science and Application Department of Earth Observation Programmes Directorate at ESRIN that focused, following the participation to the DATAGRID project (the first large European Commission funded Grid project

  12. ARBRES: Light-Weight CW/FM SAR Sensors for Small UAVs

    PubMed Central

    Aguasca, Albert; Acevo-Herrera, Rene; Broquetas, Antoni; Mallorqui, Jordi J.; Fabregas, Xavier

    2013-01-01

    This paper describes a pair of compact CW/FM airborne SAR systems for small UAV-based operation (wingspan of 3.5 m) for low-cost testing of innovative SAR concepts. Two different SAR instruments, using the C and X bands, have been developed in the context of the ARBRES project, each of them achieving a payload weight below 5 Kg and a volume of 13.5 dm3 (sensor and controller). Every system has a dual receiving channel which allows operation in interferometric or polarimetric modes. Planar printed array antennas are used in both sensors for easy system integration and better isolation between transmitter and receiver subsystems. First experimental tests on board a 3.2 m wingspan commercial radio-controlled aircraft are presented. The SAR images of a field close to an urban area have been focused using a back-projection algorithm. Using the dual channel capability, a single pass interferogram and Digital Elevation Model (DEM) has been obtained which agrees with the scene topography. A simple Motion Compensation (MoCo) module, based on the information from an Inertial+GPS unit, has been included to compensate platform motion errors with respect to the nominal straight trajectory. PMID:23467032

  13. ARBRES: light-weight CW/FM SAR sensors for small UAVs.

    PubMed

    Aguasca, Albert; Acevo-Herrera, Rene; Broquetas, Antoni; Mallorqui, Jordi J; Fabregas, Xavier

    2013-03-06

    This paper describes a pair of compact CW/FM airborne SAR systems for small UAV-based operation (wingspan of 3.5 m) for low-cost testing of innovative SAR concepts. Two different SAR instruments, using the C and X bands, have been developed in the context of the ARBRES project, each of them achieving a payload weight below 5 Kg and a volume of 13.5 dm3 (sensor and controller). Every system has a dual receiving channel which allows operation in interferometric or polarimetric modes. Planar printed array antennas are used in both sensors for easy system integration and better isolation between transmitter and receiver subsystems. First experimental tests on board a 3.2 m wingspan commercial radio-controlled aircraft are presented. The SAR images of a field close to an urban area have been focused using a back-projection algorithm. Using the dual channel capability, a single pass interferogram and Digital Elevation Model (DEM) has been obtained which agrees with the scene topography. A simple Motion Compensation (MoCo) module, based on the information from an Inertial+GPS unit, has been included to compensate platform motion errors with respect to the nominal straight trajectory.

  14. Minimizing Intra-Campaign Biases in Airborne Laser Altimetry By Thorough Calibration of Lidar System Parameters

    NASA Astrophysics Data System (ADS)

    Sonntag, J. G.; Chibisov, A.; Krabill, K. A.; Linkswiler, M. A.; Swenson, C.; Yungel, J.

    2015-12-01

    Present-day airborne lidar surveys of polar ice, NASA's Operation IceBridge foremost among them, cover large geographical areas. They are often compared with previous surveys over the same flight lines to yield mass balance estimates. Systematic biases in the lidar system, especially those which vary from campaign to campaign, can introduce significant error into these mass balance estimates and must be minimized before the data is released by the instrument team to the larger scientific community. NASA's Airborne Topographic Mapper (ATM) team designed a thorough and novel approach in order to minimize these biases, and here we describe two major aspects of this approach. First, we conduct regular ground vehicle-based surveys of lidar calibration targets, and overfly these targets on a near-daily basis during field campaigns. We discuss our technique for conducting these surveys, in particular the measures we take specifically to minimize systematic height biases in the surveys, since these can in turn bias entire campaigns of lidar data and the mass balance estimates based on them. Second, we calibrate our GPS antennas specifically for each instrument installation in a remote-sensing aircraft. We do this because we recognize that the metallic fuselage of the aircraft can alter the electromagnetic properties of the GPS antenna mounted to it, potentially displacing its phase center by several centimeters and biasing lidar results accordingly. We describe our technique for measuring the phase centers of a GPS antenna installed atop an aircraft, and show results which demonstrate that different installations can indeed alter the phase centers significantly.

  15. Antarctica X-band MiniSAR crevasse detection radar : final report.

    SciTech Connect

    Sander, Grant J.; Bickel, Douglas Lloyd

    2007-09-01

    This document is the final report for the Antarctica Synthetic Aperture Radar (SAR) Project. The project involved the modification of a Sandia National Laboratories MiniSAR system to operate at X-band in order to assess the feasibility of an airborne radar to detect crevasses in Antarctica. This radar successfully detected known crevasses at various geometries. The best results were obtained for synthetic aperture radar resolutions of at most one foot and finer. In addition to the main goal of detecting crevasses, the radar was used to assess conops for a future operational radar. The radar scanned large areas to identify potential safe landing zones. In addition, the radar was used to investigate looking at objects on the surface and below the surface of the ice. This document includes discussion of the hardware development, system capabilities, and results from data collections in Antarctica.

  16. Terrain Measurement with SAR/InSAR

    NASA Astrophysics Data System (ADS)

    Li, Deren; Liao, Mingsheng; Balz, Timo; Zhang, Lu; Yang, Tianliang

    2016-08-01

    Terrain measurement and surface motion estimation are the most important applications for commercial and scientific SAR missions. In Dragon-3, we worked on these applications, especially regarding DEM generation, surface motion estimation with SAR time- series for urban subsidence monitoring and landslide motion estimation, as well as developing tomographic SAR processing methods in urban areas.

  17. Agricultural Land Cover from Multitemporal C-Band SAR Data

    NASA Astrophysics Data System (ADS)

    Skriver, H.

    2013-12-01

    Henning Skriver DTU Space, Technical University of Denmark Ørsteds Plads, Building 348, DK-2800 Lyngby e-mail: hs@space.dtu.dk Problem description This paper focuses on land cover type from SAR data using high revisit acquisitions, including single and dual polarisation and fully polarimetric data, at C-band. The data set were acquired during an ESA-supported campaign, AgriSAR09, with the Radarsat-2 system. Ground surveys to obtain detailed land cover maps were performed during the campaign. Classification methods using single- and dual-polarisation data, and fully polarimetric data are used with multitemporal data with short revisit time. Results for airborne campaigns have previously been reported in Skriver et al. (2011) and Skriver (2012). In this paper, the short revisit satellite SAR data will be used to assess the trade-off between polarimetric SAR data and data as single or dual polarisation SAR data. This is particularly important in relation to the future GMES Sentinel-1 SAR satellites, where two satellites with a relatively wide swath will ensure a short revisit time globally. Questions dealt with are: which accuracy can we expect from a mission like the Sentinel-1, what is the improvement of using polarimetric SAR compared to single or dual polarisation SAR, and what is the optimum number of acquisitions needed. Methodology The data have sufficient number of looks for the Gaussian assumption to be valid for the backscatter coefficients for the individual polarizations. The classification method used for these data is therefore the standard Bayesian classification method for multivariate Gaussian statistics. For the full-polarimetric cases two classification methods have been applied, the standard ML Wishart classifier, and a method based on a reversible transform of the covariance matrix into backscatter intensities. The following pre-processing steps were performed on both data sets: The scattering matrix data in the form of SLC products were

  18. The analysis of signal-to-noise ratio of airborne LIDAR system under state of motion

    NASA Astrophysics Data System (ADS)

    Hao, Huang; Lan, Tian; Zhang, Yingchao; Ni, Guoqiang

    2010-11-01

    This article gives an overview of airborne LIDAR (laser light detection and ranging) system and its application. By analyzing the transmission and reception process of laser signal, the article constructs a model of echo signal of the LIDAR system, and gives some basic formulas which make up the relationship of signal-to-noise ratio, for example, the received power, the dark noise power and so on. And this article carefully studies and analyzes the impact of some important parameters in the equation on the signal-to-noise ratio, such as the atmospheric transmittance coefficient, the work distance. And the matlab software is used to simulate the detection environment, and obtains a series values of signal-to-noise (SNR) ratio under different circumstances such as sunny day, cloudy day, day, night. And the figures which describe how the SNR of LIDAR system is influenced by the critical factors are shown in the article. Finally according to the series values of signal-to-noise ratio and the figures, the SNR of LIDAR system decreases as the distance increases, and the atmospheric transmittance coefficient caused by bad weather, and also high work temperature drops the SNR. Depending on these conclusions, the LIDAR system will work even better.

  19. Airborne differential absorption lidar system for measurements of atmospheric water vapor and aerosols.

    PubMed

    Higdon, N S; Browell, E V; Ponsardin, P; Grossmann, B E; Butler, C F; Chyba, T H; Mayo, M N; Allen, R J; Heuser, A W; Grant, W B; Ismail, S; Mayor, S D; Carter, A F

    1994-09-20

    An airborne differential absorption lidar (DIAL) system has been developed at the NASA Langley Research Center for remote measurements of atmospheric water vapor (H(2)O) and aerosols. A solid-state alexandrite laser with a 1-pm linewidth and > 99.85% spectral purity was used as the on-line transmitter. Solid-state avalanche photodiode detector technology has replaced photomultiplier tubes in the receiver system, providing an average increase by a factor of 1.5-2.5 in the signal-to-noise ratio of the H(2)O measurement. By incorporating advanced diagnostic and data-acquisition instrumentation into other subsystems, we achieved additional improvements in system operational reliability and measurement accuracy. Laboratory spectroscopic measurements of H(2)O absorption-line parameters were perfo med to reduce the uncertainties in our knowledge of the absorption cross sections. Line-center H(2)O absorption cross sections were determined, with errors of 3-6%, for more than 120 lines in the 720-nm region. Flight tests of the system were conducted during 1989-1991 on the NASA Wallops Flight Facility Electra aircraft, and extensive intercomparison measurements were performed with dew-point hygrometers and H(2)O radiosondes. The H(2)O distributions measured with the DIAL system differed by ≤ 10% from the profiles determined with the in situ probes in a variety of atmospheric conditions.

  20. Airborne differential absorption lidar system for measurements of atmospheric water vapor and aerosols

    NASA Technical Reports Server (NTRS)

    Carter, Arlen F.; Allen, Robert J.; Mayo, M. Neale; Butler, Carolyn F.; Grossman, Benoist E.; Ismail, Syed; Grant, William B.; Browell, Edward V.; Higdon, Noah S.; Mayor, Shane D.; Ponsardin, Patrick; Hueser, Alene W.

    1994-01-01

    An airborne differential absorption lidar (DIAL) system has been developed at the NASA Langley Research Center for remote measurements of atmospheric water vapor (H2O) and aerosols. A solid-state alexandrite laser with a 1-pm linewidth and greater than 99.85% spectral purity was used as the on-line transmitter. Solid-state avalanche photodiode detector technology has replaced photomultiplier tubes in the receiver system, providing an average increase by a factor of 1.5-2.5 in the signal-to-noise ratio of the H2O measurement. By incorporating advanced diagnostic and data-acquisition instrumentation into other subsystems, we achieved additional improvements in system operational reliability and measurement accuracy. Laboratory spectroscopic measurements of H2O absorption-line parameters were performed to reduce the uncertainties in our knowledge of the absorption cross sections. Line-center H2O absorption cross sections were determined, with errors of 3-6%, for more than 120 lines in the 720-nm region. Flight tests of the system were conducted during 1989-1991 on the NASA Wallops Flight Facility Electra aircraft, and extensive intercomparison measurements were performed with dew-point hygrometers and H2O radiosondes. The H2O distributions measured with the DIAL system differed by less than 10% from the profiles determined with the in situ probes in a variety of atmospheric conditions.

  1. TerraSAR-X mission

    NASA Astrophysics Data System (ADS)

    Werninghaus, Rolf

    2004-01-01

    The TerraSAR-X is a German national SAR- satellite system for scientific and commercial applications. It is the continuation of the scientifically and technologically successful radar missions X-SAR (1994) and SRTM (2000) and will bring the national technology developments DESA and TOPAS into operational use. The space segment of TerraSAR-X is an advanced high-resolution X-Band radar satellite. The system design is based on a sound market analysis performed by Infoterra. The TerraSAR-X features an advanced high-resolution X-Band Synthetic Aperture Radar based on the active phased array technology which allows the operation in Spotlight-, Stripmap- and ScanSAR Mode with various polarizations. It combines the ability to acquire high resolution images for detailed analysis as well as wide swath images for overview applications. In addition, experimental modes like the Dual Receive Antenna Mode allow for full-polarimetric imaging as well as along track interferometry, i.e. moving target identification. The Ground Segment is optimized for flexible response to (scientific and commercial) User requests and fast image product turn-around times. The TerraSAR-X mission will serve two main goals. The first goal is to provide the strongly supportive scientific community with multi-mode X-Band SAR data. The broad spectrum of scientific application areas include Hydrology, Geology, Climatology, Oceanography, Environmental Monitoring and Disaster Monitoring as well as Cartography (DEM Generation) and Interferometry. The second goal is the establishment of a commercial EO-market in Europe which is driven by Infoterra. The commercial goal is the development of a sustainable EO-business so that the e.g. follow-on systems can be completely financed by industry from the profit. Due to its commercial potential, the TerraSAR-X project will be implemented based on a public-private partnership with the Astrium GmbH. This paper will describe first the mission objectives as well as the

  2. Dynamic experiment design regularization approach to adaptive imaging with array radar/SAR sensor systems.

    PubMed

    Shkvarko, Yuriy; Tuxpan, José; Santos, Stewart

    2011-01-01

    We consider a problem of high-resolution array radar/SAR imaging formalized in terms of a nonlinear ill-posed inverse problem of nonparametric estimation of the power spatial spectrum pattern (SSP) of the random wavefield scattered from a remotely sensed scene observed through a kernel signal formation operator and contaminated with random Gaussian noise. First, the Sobolev-type solution space is constructed to specify the class of consistent kernel SSP estimators with the reproducing kernel structures adapted to the metrics in such the solution space. Next, the "model-free" variational analysis (VA)-based image enhancement approach and the "model-based" descriptive experiment design (DEED) regularization paradigm are unified into a new dynamic experiment design (DYED) regularization framework. Application of the proposed DYED framework to the adaptive array radar/SAR imaging problem leads to a class of two-level (DEED-VA) regularized SSP reconstruction techniques that aggregate the kernel adaptive anisotropic windowing with the projections onto convex sets to enforce the consistency and robustness of the overall iterative SSP estimators. We also show how the proposed DYED regularization method may be considered as a generalization of the MVDR, APES and other high-resolution nonparametric adaptive radar sensing techniques. A family of the DYED-related algorithms is constructed and their effectiveness is finally illustrated via numerical simulations.

  3. Performance metrics for state-of-the-art airborne magnetic and electromagnetic systems for mapping and detection of unexploded ordnance

    NASA Astrophysics Data System (ADS)

    Doll, William E.; Bell, David T.; Gamey, T. Jeffrey; Beard, Les P.; Sheehan, Jacob R.; Norton, Jeannemarie

    2010-04-01

    Over the past decade, notable progress has been made in the performance of airborne geophysical systems for mapping and detection of unexploded ordnance in terrestrial and shallow marine environments. For magnetometer systems, the most significant improvements include development of denser magnetometer arrays and vertical gradiometer configurations. In prototype analyses and recent Environmental Security Technology Certification Program (ESTCP) assessments using new production systems the greatest sensitivity has been achieved with a vertical gradiometer configuration, despite model-based survey design results which suggest that dense total-field arrays would be superior. As effective as magnetometer systems have proven to be at many sites, they are inadequate at sites where basalts and other ferrous geologic formations or soils produce anomalies that approach or exceed those of target ordnance items. Additionally, magnetometer systems are ineffective where detection of non-ferrous ordnance items is of primary concern. Recent completion of the Battelle TEM-8 airborne time-domain electromagnetic system represents the culmination of nearly nine years of assessment and development of airborne electromagnetic systems for UXO mapping and detection. A recent ESTCP demonstration of this system in New Mexico showed that it was able to detect 99% of blind-seeded ordnance items, 81mm and larger, and that it could be used to map in detail a bombing target on a basalt flow where previous airborne magnetometer surveys had failed. The probability of detection for the TEM-8 in the blind-seeded study area was better than that reported for a dense-array total-field magnetometer demonstration of the same blind-seeded site, and the TEM-8 system successfully detected these items with less than half as many anomaly picks as the dense-array total-field magnetometer system.

  4. Development and Evaluation of an Airborne Separation Assurance System for Autonomous Aircraft Operations

    NASA Technical Reports Server (NTRS)

    Barhydt, Richard; Palmer, Michael T.; Eischeid, Todd M.

    2004-01-01

    NASA Langley Research Center is developing an Autonomous Operations Planner (AOP) that functions as an Airborne Separation Assurance System for autonomous flight operations. This development effort supports NASA s Distributed Air-Ground Traffic Management (DAG-TM) operational concept, designed to significantly increase capacity of the national airspace system, while maintaining safety. Autonomous aircraft pilots use the AOP to maintain traffic separation from other autonomous aircraft and managed aircraft flying under today's Instrument Flight Rules, while maintaining traffic flow management constraints assigned by Air Traffic Service Providers. AOP is designed to facilitate eventual implementation through careful modeling of its operational environment, interfaces with other aircraft systems and data links, and conformance with established flight deck conventions and human factors guidelines. AOP uses currently available or anticipated data exchanged over modeled Arinc 429 data buses and an Automatic Dependent Surveillance Broadcast 1090 MHz link. It provides pilots with conflict detection, prevention, and resolution functions and works with the Flight Management System to maintain assigned traffic flow management constraints. The AOP design has been enhanced over the course of several experiments conducted at NASA Langley and is being prepared for an upcoming Joint Air/Ground Simulation with NASA Ames Research Center.

  5. Performance characterization and ground testing of an airborne CO2 differential absorption LIDAR system

    NASA Astrophysics Data System (ADS)

    Senft, Daniel C.; Fox, Marsha J.; Bousek, Ronald R.; Dowling, James A.; Richter, Dale A.; Kelly, Brian T.

    1998-01-01

    The Phillips Laboratory Remote Optical Sensors (ROS) program is developing the Laser Airborne Remote Sensing (LARS) system for chemical detection using the differential absorption lidar (DIAL) technique. The system is based upon a high-power CO(subscript 2) laser which can use either the standard (superscript 12)C(superscript 16)O(subscript 2) or the (superscript 13)C(superscript 16)O(subscript 2) carbon dioxide isotopes as the lasing medium, and has output energies in excess of 4 J on the stronger laser transitions. The laser, transmitter optics, receiver telescope and optics, and monitoring equipment are mounted on a flight-qualified optical breadboard designed to mount in the Argus C-135E optical testbed aircraft operated by Phillips Laboratory. The LARS system is being prepared for initial flight experiments at Kirtland AFB, NM, in August 1997, and for chemical detection flight experiments at the Idaho National Engineering Laboratory (INEL) in September 1997. This paper briefly describes the system characterization, and presents some results from the pre- flight ground testing.

  6. Airborne water vapor DIAL system and measurements of water and aerosol profiles

    NASA Technical Reports Server (NTRS)

    Higdon, Noah S.; Browell, Edward V.

    1991-01-01

    The Lidar Applications Group at NASA Langley Research Center has developed a differential absorption lidar (DIAL) system for the remote measurement of atmospheric water vapor (H2O) and aerosols from an aircraft. The airborne H2O DIAL system is designed for extended flights to perform mesoscale investigations of H2O and aerosol distributions. This DIAL system utilizes a Nd:YAG-laser-pumped dye laser as the off-line transmitter and a narrowband, tunable Alexandrite laser as the on-line transmitter. The dye laser has an oscillator/amplifier configuration which incorporates a grating and prism in the oscillator cavity to narrow the output linewidth to approximately 15 pm. This linewidth can be maintained over the wavelength range of 725 to 730 nm, and it is sufficiently narrow to satisfy the off-line spectral requirements. In the Alexandrite laser, three intracavity tuning elements combine to produce an output linewidth of 1.1 pm. These spectral devices include a five-plate birefringent tuner, a 1-mm thick solid etalon and a 1-cm air-spaced etalon. A wavelength stability of +/- 0.35 pm is achieved by active feedback control of the two Fabry-Perot etalons using a frequency stabilized He-Ne laser as a wavelength reference. The three tuning elements can be synchronously scanned over a 150 pm range with microprocessor-based scanning electronics. Other aspects of the DIAL system are discussed.

  7. Aviation System Capacity Program Terminal Area Productivity Project: Ground and Airborne Technologies

    NASA Technical Reports Server (NTRS)

    Giulianetti, Demo J.

    2001-01-01

    Ground and airborne technologies were developed in the Terminal Area Productivity (TAP) project for increasing throughput at major airports by safely maintaining good-weather operating capacity during bad weather. Methods were demonstrated for accurately predicting vortices to prevent wake-turbulence encounters and to reduce in-trail separation requirements for aircraft approaching the same runway for landing. Technology was demonstrated that safely enabled independent simultaneous approaches in poor weather conditions to parallel runways spaced less than 3,400 ft apart. Guidance, control, and situation-awareness systems were developed to reduce congestion in airport surface operations resulting from the increased throughput, particularly during night and instrument meteorological conditions (IMC). These systems decreased runway occupancy time by safely and smoothly decelerating the aircraft, increasing taxi speed, and safely steering the aircraft off the runway. Simulations were performed in which optimal trajectories were determined by air traffic control (ATC) and communicated to flight crews by means of Center TRACON Automation System/Flight Management System (CTASFMS) automation to reduce flight delays, increase throughput, and ensure flight safety.

  8. Laboratory testing of airborne brake wear particle emissions using a dynamometer system under urban city driving cycles

    NASA Astrophysics Data System (ADS)

    Hagino, Hiroyuki; Oyama, Motoaki; Sasaki, Sousuke

    2016-04-01

    To measure driving-distance-based mass emission factors for airborne brake wear particulate matter (PM; i.e., brake wear particles) related to the non-asbestos organic friction of brake assembly materials (pads and lining), and to characterize the components of brake wear particles, a brake wear dynamometer with a constant-volume sampling system was developed. Only a limited number of studies have investigated brake emissions under urban city driving cycles that correspond to the tailpipe emission test (i.e., JC08 or JE05 mode of Japanese tailpipe emission test cycles). The tests were performed using two passenger cars and one middle-class truck. The observed airborne brake wear particle emissions ranged from 0.04 to 1.4 mg/km/vehicle for PM10 (particles up to 10 μm (in size), and from 0.04 to 1.2 mg/km/vehicle for PM2.5. The proportion of brake wear debris emitted as airborne brake wear particles was 2-21% of the mass of wear. Oxygenated carbonaceous components were included in the airborne PM but not in the original friction material, which indicates that changes in carbon composition occurred during the abrasion process. Furthermore, this study identified the key tracers of brake wear particles (e.g., Fe, Cu, Ba, and Sb) at emission levels comparable to traffic-related atmospheric environments.

  9. Alternate particle removal technologies for the Airborne Activity Confinement System at the Savannah River Site

    SciTech Connect

    Brockmann, J.E.; Adkins, C.L.J.; Gelbard, F.

    1991-09-01

    This report presents a review of the filtration technologies available for the removal of particulate material from a gas stream. It was undertaken to identify alternate filtration technologies that may be employed in the Airborne Activity Confinement System (AACS) at the Savannah River Plant. This report is organized into six sections: (1) a discussion of the aerosol source term and its definition, (2) a short discussion of particle and gaseous contaminant removal mechanisms, (3) a brief overview of particle removal technologies, (4) a discussion of the existing AACS and its potential shortcomings, (5) an enumeration of issues to be addressed in upgrading the AACS, and, (6) a detailed discussion of the identified technologies. The purpose of this report is to identity available options to the existing particle removal system. This system is in continuous operation during routine operation of the reactor. As will be seen, there are a number of options and the selection of any technology or combination of technologies will depend on the design aerosol source term (yet to be appropriately defined) as well as the flow requirements and configuration. This report does not select a specific technology. It focuses on particulate removal and qualitatively on the removal of radio-iodine and mist elimination. Candidate technologies have been selected from industrial and nuclear gas cleaning applications.

  10. Changes in airborne fungi from the outdoors to indoor air; large HVAC systems in nonproblem buildings in two different climates.

    PubMed

    Kemp, P C; Neumeister-Kemp, H G; Esposito, B; Lysek, G; Murray, F

    2003-01-01

    Little is known about the changes in occurrence and distribution of airborne fungi as they are transported in the airstream from the outdoor air through the heating, ventilation, and air conditioning (HVAC) system to the indoor air. To better understand this, airborne fungi were analyzed in the HVAC systems of two large office buildings in different climate zones. Fungal samples were taken in each of the walk-in chambers of the HVAC systems using a six-stage Andersen Sampler with malt extract agar. Results showed that fungal species changed with different locations in the HVAC systems. The outdoor air intake produced the greatest filtration effect for both the counts and species of outdoor air fungi. The colony forming unit (CFU) counts and species diversity was further reduced in the air directly after the filters. The cooling coils also had a substantial filtration effect. However, in room air the CFU counts were double and the mixture of fungal species was different from the air leaving the HVAC system at the supply air outlet in most locations. Diffusion of outdoor air fungi to the indoors did not explain the changes in the mixture of airborne fungi from the outdoor air to the indoor air, and some of the fungi present in the indoor air did not appear to be transported indoors by the HVAC systems.

  11. Observation of Planetary Oceans with Fully Polarimetric Synthetic Aperture Radar (SAR)

    NASA Astrophysics Data System (ADS)

    Moon, Wooil M.

    Synthetic Aperture Radar (SAR) is one of the most cost effective and powerful all weather tools for observation of planetary surface without sun light. The SAR systems can observe planetary surfaces with the very high resolution and large spatial coverage. We have developed and improved the algorithms for extracting quantitative information on geophysical parameters using various types of SAR data available on Earth's surface, both space-borne SAR (ERS-1/2, RADARSAT, and ENVISAT ASAR) and airborne SAR (NASA(JPL) AIRSAR). SAR is the only system that can provide a synoptic view of find wind fields near the coastal area on Earth. Many SAR images including RADARSAT and ENVISAT ASAR's alternating polarization mode and wide swath mode were to investigate the ability of retrieving sea surface wind field and the results are quite accurate and operationally acceptable. We installed corner reflectors on the nearby beach to calibrate the SAR data, and we obtained in-situ measurements from the several coast-based automatic weather systems and ocean buoys. Using the simultaneously acquired polarization ENVISAT ASAR data (HH and VV), the most appropriate polarization ratio was evaluated and applied for improving the wind retrieval model. In addition, the best combinations depending on given sea states and incidence angle ranges were investigated. The characteristics of short-period and long-period (near-inertial) internal waves are also investigated with several space-borne SAR systems. The possibility of inferring characteristics of the interior ocean dynamics from the SAR image associated with internal solitary waves was tested using a hydrodynamic interaction model (action balance equation) and a radar backscattering model (two-scale tilted Bragg model). These models were used iteratively to fit the observed SAR data to the simulated SAR. The estimated results were compared with in-situ measurements. The typical scales and the spatial and temporal characteristics of internal

  12. Joint Tactical Radio System Handheld, Manpack, and Small Form Fit Radios (JTRS HMS)

    DTIC Science & Technology

    2015-12-01

    waveforms: SRW, Single Channel Ground and Airborne Radio System, satellite communication, and Mobile-User Objective System. The Manpack Radio is utilized...2015 SAR March 21, 2016 18:21:36 UNCLASSIFIED 6 Executive Summary HMS is structured as a single acquisition program. The program completed the EMD...include: SRW, Single Channel Ground and Airborne Radio System (Army managed waveform), Satellite Communications (Army managed waveform), and Mobile

  13. A P-band SAR interference filter

    NASA Technical Reports Server (NTRS)

    Taylor, Victor B.

    1992-01-01

    The synthetic aperture radar (SAR) interference filter is an adaptive filter designed to reduce the effects of interference while minimizing the introduction of undesirable side effects. The author examines the adaptive spectral filter and the improvement in processed SAR imagery using this filter for Jet Propulsion Laboratory Airborne SAR (JPL AIRSAR) data. The quality of these improvements is determined through several data fidelity criteria, such as point-target impulse response, equivalent number of looks, SNR, and polarization signatures. These parameters are used to characterize two data sets, both before and after filtering. The first data set consists of data with the interference present in the original signal, and the second set consists of clean data which has been coherently injected with interference acquired from another scene.

  14. Viral load distribution in SARS outbreak.

    PubMed

    Chu, Chung-Ming; Cheng, Vincent C C; Hung, Ivan F N; Chan, Kin-Sang; Tang, Bone S F; Tsang, Thomas H F; Chan, Kwok-Hung; Yuen, Kwok-Yung

    2005-12-01

    An unprecedented community outbreak of severe acute respiratory syndrome (SARS) occurred in the Amoy Gardens, a high-rise residential complex in Hong Kong. Droplet, air, contaminated fomites, and rodent pests have been proposed to be mechanisms for transmitting SARS in a short period. We studied nasopharyngeal viral load of SARS patients on admission and their geographic distribution. Higher nasopharyngeal viral load was found in patients living in adjacent units of the same block inhabited by the index patient, while a lower but detectable nasopharyngeal viral load was found in patients living further away from the index patient. This pattern of nasopharyngeal viral load suggested that airborne transmission played an important part in this outbreak in Hong Kong. Contaminated fomites and rodent pests may have also played a role.

  15. Effect of heating-ventilation-air conditioning system sanitation on airborne fungal populations in residential environments.

    PubMed

    Garrison, R A; Robertson, L D; Koehn, R D; Wynn, S R

    1993-12-01

    Commercial air duct sanitation services are advertised to the public as being effective in reducing indoor aeroallergen levels despite the absence of published supporting data. Eight residential heat-ventilation-air conditioning (HVAC) systems in six homes and seven HVAC systems in five homes in winter and summer, respectively, were sampled to determine fungal colony forming units (CFUs) prior to and after an HVAC sanitation procedure was performed by a local company. Two houses in which no sanitation procedure was performed served as controls in each study phase. Two sample sets were obtained at each HVAC system prior to cleaning in order to determine baseline CFU levels. The test HVAC systems were then cleaned, and the HVAC systems allowed to operate as desired by the residents. Posttreatment sampling was performed 48 hours and then weekly after cleaning for 8 weeks. The HVAC systems were analyzed by exposing sterile 2% malt extract media plates at a 90-degree angle to the air flow at the air supply and air return vents. The baseline CFUs were similar in the control and study houses. Eight weeks after sanitation, the study houses demonstrated an overall CFU reduction of 92% during winter and 84% during summer. No reduction in CFU values was observed over the 8-week study period for the houses selected as controls. Further, HVAC sanitation appeared to reduce the number of fungal colonies entering and leaving the HVAC system, suggesting that the HVAC contained a significant percentage of the total fungal load in these homes. These data suggest that HVAC sanitation may be an effective tool in reducing airborne fungal populations in residential environments.

  16. Use of SAR in Regional Methane Exchange Studies

    NASA Technical Reports Server (NTRS)

    Morrissey, L. A.; Livingston, G. P.; Durden, S. L.

    1994-01-01

    Significant sources of uncertainty in global trace gas budgets are due to lack of knowledge concerning the areal and temporal extent of source and sink areas. Synthetic aperture radar (SAR) is particularly suited to studies of northern ecosystems because of its all-weather operating capability which enables the acquisition of seasonal data. As key controls on methane exchange, the ability to differentiate major vegetation communities, inundation, and leaf area index (LAI) with satellite and airborne SAR data would increase the accuracy and precision of regional and seasonal estimates of methane exchange. The utility of SAR data for monitoring key controls on methane emissions from Arctic and boreal ecosystems is examined.

  17. InSAR observations of strain accumulation and fault creep along the Chaman Fault system, Pakistan and Afghanistan

    NASA Astrophysics Data System (ADS)

    Fattahi, Heresh; Amelung, Falk

    2016-08-01

    We use 2004-2011 Envisat synthetic aperture radar imagery and InSAR time series methods to estimate the contemporary rates of strain accumulation in the Chaman Fault system in Pakistan and Afghanistan. At 29 N we find long-term slip rates of 16 ± 2.3 mm/yr for the Ghazaband Fault and of 8 ± 3.1 mm/yr for the Chaman Fault. This makes the Ghazaband Fault one of the most hazardous faults of the plate boundary zone. We further identify a 340 km long segment displaying aseismic surface creep along the Chaman Fault, with maximum surface creep rate of 8.1 ± 2 mm/yr. The observation that the Chaman Fault accommodates only 30% of the relative plate motion between India and Eurasia implies that the remainder is accommodated south and east of the Katawaz block microplate.

  18. Airborne Wind Shear Detection and Warning Systems: First Combined Manufacturers' and Technologists' Conference

    NASA Technical Reports Server (NTRS)

    Spady, Amos A., Jr. (Compiler); Bowles, Roland L. (Compiler); Schlickenmaier, Herbert (Compiler)

    1988-01-01

    The purpose of the meeting was to transfer significant, ongoing results gained during the first year of the joint NASA/FAA Airborne Wind Shear Program to the technical industry and to pose problems of current concern to the combined group. It also provided a forum for manufacturers to review forward-looking technology concepts and for technologists to gain an understanding of FAA certification requirements and the problems encountered by the manufacturers during the development of airborne equipment.

  19. Airborne Camera System for Real-Time Applications - Support of a National Civil Protection Exercise

    NASA Astrophysics Data System (ADS)

    Gstaiger, V.; Romer, H.; Rosenbaum, D.; Henkel, F.

    2015-04-01

    In the VABENE++ project of the German Aerospace Center (DLR), powerful tools are being developed to aid public authorities and organizations with security responsibilities as well as traffic authorities when dealing with disasters and large public events. One focus lies on the acquisition of high resolution aerial imagery, its fully automatic processing, analysis and near real-time provision to decision makers in emergency situations. For this purpose a camera system was developed to be operated from a helicopter with light-weight processing units and microwave link for fast data transfer. In order to meet end-users' requirements DLR works close together with the German Federal Office of Civil Protection and Disaster Assistance (BBK) within this project. One task of BBK is to establish, maintain and train the German Medical Task Force (MTF), which gets deployed nationwide in case of large-scale disasters. In October 2014, several units of the MTF were deployed for the first time in the framework of a national civil protection exercise in Brandenburg. The VABENE++ team joined the exercise and provided near real-time aerial imagery, videos and derived traffic information to support the direction of the MTF and to identify needs for further improvements and developments. In this contribution the authors introduce the new airborne camera system together with its near real-time processing components and share experiences gained during the national civil protection exercise.

  20. Real-time atmospheric absorption spectra for in-flight tuning of an airborne dial system

    NASA Technical Reports Server (NTRS)

    Dombrowski, M.; Walden, H.; Schwemmer, G. K.; Milrod, J.; Korb, C. L.

    1986-01-01

    Real-time measurements of atmospheric absorption spectra are displayed and used to precisely calibrate and fix the frequency of an Alexandrite laser to specific oxygen absorption features for airborne Differential Absorption Lidar (DIAL) measurements of atmospheric pressure and temperature. The DIAL system used contains two narrowband tunable Alexandrite lasers: one is electronically scanned to tune to oxygen absorption features for on-line signals while the second is used to obtain off-line (nonabsorbed) atmospheric return signals. The lidar operator may select the number of shots to be averaged, the altitude, and altitude interval over which the signals are averaged using single key stroke commands. The operator also determines exactly which oxygen absorption lines are scanned by comparing the line spacings and relative strengths with known line parameters, thus calibrating the laser wavelength readout. The system was used successfully to measure the atmospheric pressure profile on the first flights of this lidar, November 20, and December 9, 1985, aboard the NASA Wallops Electra aircraft.

  1. Airborne pseudolite aiding BeiDou system to improve positioning precision in low latitude areas

    NASA Astrophysics Data System (ADS)

    Ma, Weihua; Yuan, Jianping; Luo, Jianjun

    2005-11-01

    The BeiDou System (BDS), which has three satellites in Geostationary Earth Orbit (GEO), is a regional satellite navigation system of China and its positioning performance is notorious in low latitude areas. The two mending plans using Airborne Pseudolite (APL) aiding BDS to improve navigation precision in such areas are put forward. Plan I uses three BDS satellites and one APS to supply navigation data and Plan II employs two BDS satellites, one APS and altimeter to work. Both of the plans adopt point positioning with code pseudo-range algorithm. Geometric Dilution of Precision (GDOP), which is calculated by Positioning Error Transfer Coefficient Matrix (PETCM), is used to evaluate the positioning performance of new plans. PETCM is predigested when user is in low latitude areas. The key elements of predigested PETCM that effect the Geometric Dilution of Precision (GDOP) are analyzed. The character of GDOP is forecasted easily with the predigested PETCM. The simulations show that the precision of plans are expected to be hundreds of meters except some region where the latitudes of user and APL are close to each other and Plan II is better than plan I. The phenomenal consists with the theoretical analysis.

  2. An airborne low SWaP-C UAS sense and avoid system

    NASA Astrophysics Data System (ADS)

    Wang, Zhonghai; Lin, Xingping; Xiang, Xingyu; Blasch, Erik; Pham, Khanh; Chen, Genshe; Shen, Dan; Jia, Bin; Wang, Gang

    2016-05-01

    This paper presents a low size, weight and power - cost (SWaP-C) airborne sense and avoid (ABSAA) system, which is based on a linear frequency modulated continuous wave (LFMCW) radar and can be mounted on small unmanned aircraft system (UAS). The system satisfies the constraint of the available sources on group 2/3 UAS. To obtain the desired sense and avoid range, a narrow band frequency (or range) scanning technique is applied for reducing the receiver's noise floor to improve its sensitivity, and a digital signal integration with fast Fourier transform (FFT) is applied to enhance the signal to noise ratio (SNR). The gate length and chirp rate are intelligently adapted to not only accommodate different object distances, speeds and approaching angle conditions, but also optimize the detection speed, resolution and coverage range. To minimize the radar blind zone, a higher chirp rate and a narrowband intermediate frequency (IF) filter are applied at the near region with a single antenna signal for target detection. The offset IF frequency between transmitter (TX) and receiver (RX) is designed to mitigate the TX leakage to the receiver, especially at close distances. Adaptive antenna gain and beam-width are utilized for searching at far distance and fast 360 degree middle range. For speeding up the system update rate, lower chirp rates and wider IF and baseband filters are applied for obtaining larger range scanning step length out of the near region. To make the system working with a low power transmitter (TX), multiple-antenna beamforming, digital signal integration with FFT, and a much narrower receiver (RX) bandwidth are applied at the far region. The ABSAA system working range is 2 miles with a 1W transmitter and single antenna signal detection, and it is 5 miles when a 5W transmitter and 4-antenna beamforming (BF) are applied.

  3. SAR image registration based on Susan algorithm

    NASA Astrophysics Data System (ADS)

    Wang, Chun-bo; Fu, Shao-hua; Wei, Zhong-yi

    2011-10-01

    Synthetic Aperture Radar (SAR) is an active remote sensing system which can be installed on aircraft, satellite and other carriers with the advantages of all day and night and all-weather ability. It is the important problem that how to deal with SAR and extract information reasonably and efficiently. Particularly SAR image geometric correction is the bottleneck to impede the application of SAR. In this paper we introduces image registration and the Susan algorithm knowledge firstly, then introduces the process of SAR image registration based on Susan algorithm and finally presents experimental results of SAR image registration. The Experiment shows that this method is effective and applicable, no matter from calculating the time or from the calculation accuracy.

  4. A Nadir-adjusted Airborne Multi Spectral Imaging System (NAMSIS) for high-resolution remote sensing of carbon fluxes

    NASA Astrophysics Data System (ADS)

    Jiang, Z.; Scott, S.; Rahman, A. F.

    2012-12-01

    Satellite remote sensing is widely used in vegetation monitoring, water stress detection and carbon cycle modeling. However, image pixels from high temporal resolution satellite sensors (such as MODIS) have coarse spatial resolution, much larger than the canopies they are supposed to characterize. An alternative solution for on-demand high spatial resolution remote sensing is sensors onboard low-flying aircrafts. Airborne remote sensing has been traditionally used in crop management studies. In this presentation we demonstrate the application of a relatively low-cost airborne sensor system with customized spectral band combinations for studying forest carbon fluxes. Our team has developed an Inertia Measurement Unit (IMU) controlled automated system to detach aircraft movements (pitch and roll) and engine vibration from the six-band programmable imager, in order to maintain the sensor at nadir view at all times during the flight. Flight lines are configured by a GPS-controleld system to simulate MODIS pixels. A feature-based algorithm is used to automatically generate a mosaic of individual images along the flight lines. This algorithm eliminates the need to mosiac and georeference images manually. An empirical line method is used to calculate reflectance from the raw data. Images from this airborne system produce reflectance values that are comparable with MODIS reflectance product. These high spatial resolution (~0.5 m) images deliver detailed information about tree species and phenological conditions within each MODIS pixel, and thus permit a high resolution spatio-temporal assessment of forest carbon fluxes.

  5. Joint influences of aerodynamic flow field and aerodynamic heating of the dome on imaging quality degradation of airborne optical systems.

    PubMed

    Xiao, Haosu; Zuo, Baojun; Tian, Yi; Zhang, Wang; Hao, Chenglong; Liu, Chaofeng; Li, Qi; Li, Fan; Zhang, Li; Fan, Zhigang

    2012-12-20

    We investigated the joint influences exerted by the nonuniform aerodynamic flow field surrounding the optical dome and the aerodynamic heating of the dome on imaging quality degradation of an airborne optical system. The Spalart-Allmaras model provided by FLUENT was used for flow computations. The fourth-order Runge-Kutta algorithm based ray tracing program was used to simulate optical transmission through the aerodynamic flow field and the dome. Four kinds of imaging quality evaluation parameters were presented: wave aberration of the exit pupil, point spread function, encircled energy, and modulation transfer function. The results show that the aero-optical disturbance of the aerodynamic flow field and the aerodynamic heating of the dome significantly affect the imaging quality of an airborne optical system.

  6. Comprehensive analysis of imaging quality degradation of an airborne optical system for aerodynamic flow field around the optical window.

    PubMed

    Hao, Chenglong; Chen, Shouqian; Zhang, Wang; Ren, Jinhan; Li, Chong; Pang, Hongjun; Wang, Honghao; Liu, Qian; Wang, Chao; Zou, Huiying; Fan, Zhigang

    2013-11-20

    We investigated the influences exerted by the nonuniform aerodynamic flow field surrounding the optical window on the imaging quality degradation of an airborne optical system. The density distribution of flow fields around three typical optical windows, including a spherical window, an ellipsoidal window, and a paraboloidal window, were calculated by adopting the Reynolds-averaged Navier-Stokes equations with the Spalart-Allmaras model provided by FLUENT. The fourth-order Runge-Kutta algorithm based ray-tracing program was used to simulate the optical transmission through the aerodynamic flow field. Four kinds of imaging quality evaluation parameters were presented: wave aberration of the entrance pupil, point spread function, encircled energy, and modulation transfer function. The results show that the imaging quality of the airborne optical system was affected by the shape of the optical window and angle of attack of the aircraft.

  7. Scanning infrared remote sensing system for identification, visualization, and quantification of airborne pollutants

    NASA Astrophysics Data System (ADS)

    Harig, Roland; Matz, Gerhard; Rusch, Peter

    2002-02-01

    Remote sensing by Fourier-transform infrared (FTIR) spectrometry allows detection, identification, and quantification of airborne pollutants. In the case of leaks in pipelines or leaks in chemical plants, chemical accidents, terrorism, or war, hazardous compounds are often released into the atmosphere. Various Fourier-transform infrared spectrometers have been developed for the remote detection and identification of hazardous clouds. However, for the localization of a leak and a complete assessment of the situation in the case of the release of a hazardous cloud, information about the position and the size of a cloud is essential. Therefore, an imaging passive remote sensing system comprised of an interferometer (Bruker OPAG 22), a data acquisition, processing, and control system with a digital signal processor (FTIR DSP), an azimuth-elevation-scanning mirror, a video system with a DSP, and a personal computer has been developed. The FTIR DSP system controls the scanning mirror, collects the interferograms, and performs the Fourier transformation. The spectra are transferred to a personal computer and analyzed by a real-time identification algorithm that does not require background spectra for the analysis. The results are visualized by a video image, overlaid by false color images. For each target compound of a spectral library, images of the coefficient of correlation, the signal to noise ratio, the brightness temperature of the background, the difference between the temperature of the ambient air and the brightness temperature of the background, and the noise equivalent column density are produced. The column densities of all directions in which a target compound has been identified may be retrieved by a nonlinear least squares fitting algorithm and an additional false color image is displayed. The system has a high selectivity, low noise equivalent spectral radiance, and it allows identification, visualization, and quantification of pollutant clouds.

  8. Concentrations and properties of airborne particles in the Mexico City subway system

    NASA Astrophysics Data System (ADS)

    Mugica-Álvarez, V.; Figueroa-Lara, J.; Romero-Romo, M.; Sepúlveda-Sánchez, J.; López-Moreno, T.

    2012-03-01

    Samples of PM10 and PM2.5 were collected using High Vol and MiniVol devices on the platform of a subway station in Mexico City and in an outdoor location close to it, using such devices. Soluble extractable organic matter (SEOM) and water solubility of metals were determined. Elemental composition and solubility of trace metals were determined and individual aerosol particles were studied with scanning electron microscopy (SEM) and energy dispersive X-ray spectrometry (EDX). The concentration levels in both sizes were similar during all days with the exception of weekends, especially on Sunday when activity decreases due to lower trains' frequency. The largest particles concentrations in the subway were found from 06:00 to 14:00 and the lowest concentrations were registered from 22:00 to 06:00. Concentrations of PM2.5 ranging between 60 μg m-3 and 93 μg m-3 (10% and 90% percentile) in the subway were 6% larger than outside, whereas PM10 were 20% larger than outside ranging from 88 μg m-3 to 145 μg m-3. Greater Fe, Cu, Ni, Cr and Mn concentrations were quantified in the subway samples as compared to the airborne particles by up to 2.5, 9, 1.8, 2.0 and 2.6 times, respectively. Even when the solubility percent of these metals in the subway PM was smaller than in the outdoor airborne particles, metals' concentrations were greater. SEM and EDS exhibit the presence of many individual particles with a large metal content in the subway samples. Correlation analysis showed the influence of outdoor PM in the subway aerosols, but characterization revealed also important differences in the presence of metals and SEOM, due to underground sources such as friction, brake system, and metals from sparking. This means that a large number of commuters are exposed during labor days to large toxic metals concentrations as they transit.

  9. Circular SAR GMTI

    NASA Astrophysics Data System (ADS)

    Page, Douglas; Owirka, Gregory; Nichols, Howard; Scarborough, Steven

    2014-06-01

    We describe techniques for improving ground moving target indication (GMTI) performance in multi-channel synthetic aperture radar (SAR) systems. Our approach employs a combination of moving reference processing (MRP) to compensate for defocus of moving target SAR responses and space-time adaptive processing (STAP) to mitigate the effects of strong clutter interference. Using simulated moving target and clutter returns, we demonstrate focusing of the target return using MRP, and discuss the effect of MRP on the clutter response. We also describe formation of adaptive degrees of freedom (DOFs) for STAP filtering of MRP processed data. For the simulated moving target in clutter example, we demonstrate improvement in the signal to interference plus noise (SINR) loss compared to more standard algorithm configurations. In addition to MRP and STAP, the use of tracker feedback, false alarm mitigation, and parameter estimation techniques are also described. A change detection approach for reducing false alarms from clutter discretes is outlined, and processing of a measured data coherent processing interval (CPI) from a continuously orbiting platform is described. The results demonstrate detection and geolocation of a high-value target under track. The endoclutter target is not clearly visible in single-channel SAR chips centered on the GMTI track prediction. Detections are compared to truth data before and after geolocation using measured angle of arrival (AOA).

  10. Rugged, reliable, and secured data storage solutions for airborne ISR systems

    NASA Astrophysics Data System (ADS)

    Tsur, Ofer

    2004-08-01

    Rugged, reliable and secure data storage is of major concern to engineers designing Airborne Intelligence, Surveillance, Reconnaissance (ISR) systems. Operation under harsh conditions of shock, vibration and high altitude in extreme temperature ranges is an essential requirement. Due to its rotating mechanism, a mechanical disk cannot provide top-level data reliability in such an environment. Other Commercial Off The Shelf (COTS) solutions can replace mechanical disks. This paper describes some of these alternatives and highlights their cost-effectiveness. One alternative is a ruggedized mechanical disk, a mechanical disk sealed in a rigid cartridge. Another alternative is the solid-state flash disk that, like the mechanical disk, retains data when power is off, and is a "drop-in replacement" for the mechanical disk for reliability in harsh environments. Flash disk manufacturers incorporate special methods to enhance endurance and reliability for military designers. This paper also describes the mandatory requirements of the DoD, NSA and the US Air Force for erasing confidential data in storage devices. This issue is vital, especially since the P-3 landed forcibly on China"s soil. Some flash disk vendors meet security requirements with Fast Secure Erase and Sanitize, enabling data declassification in seconds, even without power.

  11. Estimation of foliar and woody biomass using an airborne lidar system

    SciTech Connect

    Maclean, G.A.

    1988-01-01

    The NASA Airborne Oceanographic Lidar was flown over forested terrain at two sites, producing a digital measurement of the canopy profile. The primary site was International Paper Corporation's Southlands Experimental Forest near Bainbridge, Georgia. The secondary site was the Department of Energy's Savannah River Plant near Aikens, South Carolina. Both sites are located on the southern coastal plain, and contain areas typical of both managed and unmanaged stands of southern pines. Concurrently acquired aerial photography and aircraft inertial-navigation-system data permitted precise location of the laser's track on the ground. While three laser pulsing rates were used in data collection, no significant effects to forest canopy profile area measurement were detected due to this factor. Resulting equations can be used in predicting forest biomass and timber volume at different sites with similar species composition and site conditions. Any stand level estimation precision can be achieved through the employment of sufficient sampling intensity. Recommendations for future lidar studies of forest canopies are given and potential applications merging lidar data with satellite imagery are discussed.

  12. System for processing of airborne images of forest ecosystems using high spectral and spatial resolution data

    NASA Astrophysics Data System (ADS)

    Kozoderov, V. V.; Dmitriev, E. V.; Kamentsev, V. P.

    2014-12-01

    The developed hardware and software system for the recognition of natural and man-made objects based on the airborne hyperspectral sensing implements flight tasks on selected survey routes and computational procedures for solving applied problems that occur in data processing. The basics of object recognition based on obtained images of high spectral and spatial resolution in mathematical terms of sets of sites and labels and the basics of interrelations between separate resolution elements (pixels) for selected object classes are presented. Features of energy minimization of the processed scene are depicted as a target function of the optimization of computation and regularization of the solution of the considered problems as a theoretical basis for distinguishing between classes of objects in the presence of boundaries between them. Examples of the formation of information layers of recorded spectra for selected "pure species" of pine and birch forests are cited, with the separation of illuminated and shaded pixels, which increases the accuracy of object recognition in the processing of the images.

  13. HSI mapping of marine and coastal environments using the advanced airborne hyperspectral imaging system (AAHIS)

    NASA Astrophysics Data System (ADS)

    Holasek, Rick E.; Portigal, Frederick P.; Mooradian, Gregory C.; Voelker, Mark A.; Even, Detlev M.; Fene, Michael W.; Owensby, Pamela D.; Breitwieser, David S.

    1997-08-01

    The advanced airborne hyperspectral imaging system (AAHIS) is an operational, high signal-to-noise ratio, high resolution, integrated hyperspectral imaging spectrometer. The compact, lightweight and portable AAHIS system is normally flown in Piper Aztec aircraft. AAHIS collect 'push- broom' data with 385 spatial channels and 288 simultaneous spectral channels from 433 nm to 832 nm, recording at 12 bits up to 55 frames/second. Typical operation incorporates on-chip pixel binning of four pixels spectrally and two pixels spatially, increasing the signal-to-noise ratio and reducing data rate. When binned, the spectral resolution is 5.5 nm and the instantaneous field-of-view is 1 mrad, resulting in a ground sample distance of 0.5 m from 500 m altitude. The sensor is optimized for littoral region remote sensing for a variety of civilian and defense applications including ecosystem surveying and inventory, detection and monitoring of environmental pollution, infrastructure mapping, and surveillance. Since August 1994, AAHIS has acquired over 120 GB of hyperspectral image data of littoral, urban, desert and tropical scenes. System upgrades include real-time spectral image processing, integrated flight navigation and 3-axis image stabilization. A description of the sensor system, its performance characteristics, and several processed images demonstrating material discrimination are presented. The remote assessment, characterization, and mapping of coral reef health and species identification and floral species at Nu'upia Ponds, are shown and compared to extensive ground truthing in and around Kaneohe Bay, Oahu, Hawaii. SETS emphasizes providing georegistered, GIS-integrated, value- added data products for customers to help them solve real- world problems.

  14. Capability of air filters to retain airborne bacteria and molds in heating, ventilating and air-conditioning (HVAC) systems.

    PubMed

    Möritz, M; Peters, H; Nipko, B; Rüden, H

    2001-07-01

    The capability of air filters (filterclass: F6, F7) to retain airborne outdoor microorganisms was examined in field experiments in two heating, ventilating and air conditioning (HVAC) systems. At the beginning of the 15-month investigation period, the first filter stages of both HVAC systems were equipped with new unused air filters. The number of airborne bacteria and molds before and behind the filters were determined simultaneously in 14 days-intervals using 6-stage Andersen cascade impactors. Under relatively dry (< 80% R. H.) and warm (> 12 degrees C) outdoor air conditions air filters led to a marked reduction of airborne microorganism concentrations (bacteria by approximately 70% and molds by > 80%). However, during long periods of high relative humidity (> 80% R. H.) a proliferation of bacteria on air filters with subsequent release into the filtered air occurred. These microorganisms were mainly smaller than 1.1 microns therefore being part of the respirable fraction. The results showed furthermore that one possibility to avoid microbial proliferation is to limit the relative humidity in the area of the air filters to 80% R. H. (mean of 3 days), e.g. by using preheaters in front of air filters in HVAC-systems.

  15. SWUIS-A: A Versatile, Low-Cost UV/VIS/IR Imaging System for Airborne Astronomy and Aeronomy Research

    NASA Technical Reports Server (NTRS)

    Durda, Daniel D.; Stern, S. Alan; Tomlinson, William; Slater, David C.; Vilas, Faith

    2001-01-01

    We have developed and successfully flight-tested on 14 different airborne missions the hardware and techniques for routinely conducting valuable astronomical and aeronomical observations from high-performance, two-seater military-type aircraft. The SWUIS-A (Southwest Universal Imaging System - Airborne) system consists of an image-intensified CCD camera with broad band response from the near-UV to the near IR, high-quality foreoptics, a miniaturized video recorder, an aircraft-to-camera power and telemetry interface with associated camera controls, and associated cables, filters, and other minor equipment. SWUIS-A's suite of high-quality foreoptics gives it selectable, variable focal length/variable field-of-view capabilities. The SWUIS-A camera frames at 60 Hz video rates, which is a key requirement for both jitter compensation and high time resolution (useful for occultation, lightning, and auroral studies). Broadband SWUIS-A image coadds can exceed a limiting magnitude of V = 10.5 in <1 sec with dark sky conditions. A valuable attribute of SWUIS-A airborne observations is the fact that the astronomer flies with the instrument, thereby providing Space Shuttle-like "payload specialist" capability to "close-the-loop" in real-time on the research done on each research mission. Key advantages of the small, high-performance aircraft on which we can fly SWUIS-A include significant cost savings over larger, more conventional airborne platforms, worldwide basing obviating the need for expensive, campaign-style movement of specialized large aircraft and their logistics support teams, and ultimately faster reaction times to transient events. Compared to ground-based instruments, airborne research platforms offer superior atmospheric transmission, the mobility to reach remote and often-times otherwise unreachable locations over the Earth, and virtually-guaranteed good weather for observing the sky. Compared to space-based instruments, airborne platforms typically offer

  16. Data Acquisition and Processing System for Airborne Wind Profiling with a Pulsed, 2-Micron, Coherent-Detection, Doppler Lidar System

    NASA Technical Reports Server (NTRS)

    Beyon, J. Y.; Koch, G. J.; Kavaya, M. J.

    2010-01-01

    A data acquisition and signal processing system is being developed for a 2-micron airborne wind profiling coherent Doppler lidar system. This lidar, called the Doppler Aerosol Wind Lidar (DAWN), is based on a Ho:Tm:LuLiF laser transmitter and 15-cm diameter telescope. It is being packaged for flights onboard the NASA DC-8, with the first flights in the summer of 2010 in support of the NASA Genesis and Rapid Intensification Processes (GRIP) campaign for the study of hurricanes. The data acquisition and processing system is housed in a compact PCI chassis and consists of four components such as a digitizer, a digital signal processing (DSP) module, a video controller, and a serial port controller. The data acquisition and processing software (DAPS) is also being developed to control the system including real-time data analysis and display. The system detects an external 10 Hz trigger pulse and initiates the data acquisition and processing process, and displays selected wind profile parameters such as Doppler shift, power distribution, wind directions and velocities. Doppler shift created by aircraft motion is measured by an inertial navigation/GPS sensor and fed to the signal processing system for real-time removal of aircraft effects from wind measurements. A general overview of the system and the DAPS as well as the coherent Doppler lidar system is presented in this paper.

  17. MRV System Development for REDD+ in Indonesia: Pol-SAR Application

    NASA Astrophysics Data System (ADS)

    Raimadoya, Mahmud; Gunawan, Adrianto

    2013-08-01

    An important and critical requirement for the implementation of REDD+ will be the establishment of an independent MRV (Monitoring, Reporting, and V erification) procedure. This paper presents the progress in the establishment of MRV model for forest plantation (HTI) in Indonesia. The objectives of the study were: (1) to observe the impact of HTI on the degraded peat land; (2) to initiate MRV procedure standardized to 2006 IPCC Guidelines (AFOLU Sector); and (3) to explore SAR application for MRV. The HTI test site is located in Ogan Komering Ilir (OKI) District of South Sumatera Province (total area of 585,305 Ha), where the first planting operation was started on 2004-2005. The study involved multi- temporal and multi-mission image archives of 15 years period (1995-2009). Preliminary detailed study was implemented on the four selected imageries: Landsat- ETM (1995 & 2000), SPOT-4 (2004) and ALOS/PALSAR (2009). The result was presented in terms of carbon stock and carbon stock change (Tier-1). Using 1995 as the baseline, HTI intervention (2009) showed a positive impact with carbon stock increase of 24%. While the other two showed carbon stock decreases of -18% (2000) due to 1998 forest fire, and - 8% (2004) as the natural forest recovery was took place.

  18. Two-UAV Intersection Localization System Based on the Airborne Optoelectronic Platform

    PubMed Central

    Bai, Guanbing; Liu, Jinghong; Song, Yueming; Zuo, Yujia

    2017-01-01

    To address the limitation of the existing UAV (unmanned aerial vehicles) photoelectric localization method used for moving objects, this paper proposes an improved two-UAV intersection localization system based on airborne optoelectronic platforms by using the crossed-angle localization method of photoelectric theodolites for reference. This paper introduces the makeup and operating principle of intersection localization system, creates auxiliary coordinate systems, transforms the LOS (line of sight, from the UAV to the target) vectors into homogeneous coordinates, and establishes a two-UAV intersection localization model. In this paper, the influence of the positional relationship between UAVs and the target on localization accuracy has been studied in detail to obtain an ideal measuring position and the optimal localization position where the optimal intersection angle is 72.6318°. The result shows that, given the optimal position, the localization root mean square error (RMS) will be 25.0235 m when the target is 5 km away from UAV baselines. Finally, the influence of modified adaptive Kalman filtering on localization results is analyzed, and an appropriate filtering model is established to reduce the localization RMS error to 15.7983 m. Finally, An outfield experiment was carried out and obtained the optimal results: σB=1.63×10−4 (°), σL=1.35×10−4 (°), σH=15.8 (m), σsum=27.6 (m), where σB represents the longitude error, σL represents the latitude error, σH represents the altitude error, and σsum represents the error radius. PMID:28067814

  19. Two-UAV Intersection Localization System Based on the Airborne Optoelectronic Platform.

    PubMed

    Bai, Guanbing; Liu, Jinghong; Song, Yueming; Zuo, Yujia

    2017-01-06

    To address the limitation of the existing UAV (unmanned aerial vehicles) photoelectric localization method used for moving objects, this paper proposes an improved two-UAV intersection localization system based on airborne optoelectronic platforms by using the crossed-angle localization method of photoelectric theodolites for reference. This paper introduces the makeup and operating principle of intersection localization system, creates auxiliary coordinate systems, transforms the LOS (line of sight, from the UAV to the target) vectors into homogeneous coordinates, and establishes a two-UAV intersection localization model. In this paper, the influence of the positional relationship between UAVs and the target on localization accuracy has been studied in detail to obtain an ideal measuring position and the optimal localization position where the optimal intersection angle is 72.6318°. The result shows that, given the optimal position, the localization root mean square error (RMS) will be 25.0235 m when the target is 5 km away from UAV baselines. Finally, the influence of modified adaptive Kalman filtering on localization results is analyzed, and an appropriate filtering model is established to reduce the localization RMS error to 15.7983 m. Finally, An outfield experiment was carried out and obtained the optimal results: σ B = 1.63 × 10 - 4 ( ° ) , σ L = 1.35 × 10 - 4 ( ° ) , σ H = 15.8 ( m ) , σ s u m = 27.6 ( m ) , where σ B represents the longitude error, σ L represents the latitude error, σ H represents the altitude error, and σ s u m represents the error radius.

  20. Development of Unmanned Airborne System (UAS) instrumentation for air-sea-ice interaction research

    NASA Astrophysics Data System (ADS)

    Reineman, B. D.; Lenain, L.; Melville, W. K.

    2011-12-01

    We have developed Unmanned Airborne System (UAS) instrumentation packages to directly measure air-sea momentum transfer, as well as latent, sensible, and radiative heat fluxes, topography, and surface wave kinematics. Two UAS (BAE Manta C1s) flying in vertical formation over the ocean will allow the direct measurement of air-sea fluxes within the marine atmospheric boundary layer, and, with onboard high-resolution video and laser altimetry, simultaneous observation of sea surface kinematics and sea-ice topography. The low altitude required for accurate air-sea or air-ice flux measurements is below the typical safety limit of manned research aircraft; however, with advancements in laser altimeters, small-aircraft flight control, and real-time Differential GPS, it now is within the capability of the UAS platform. Fast response turbulence, hygrometer, and temperature probes in the lower UAS permit surface layer flux measurements, and short and long wave radiometers in the upper UAS allow the determination of net radiation, surface temperature, and albedo. Engineering test flights of the two UAS over land were performed in January 2011 at Camp Roberts, CA. The tests demonstrated the capability of the systems to measure vertical profiles of georeferenced wind, temperature, and moisture content, as well as momentum flux and sensible, latent, and radiative heat fluxes. UAS-derived fluxes from low-altitude (20 -- 30 m) flights are in agreement with fluxes measured by a nearby tower-mounted sonic anemometer-based eddy covariance system. We present a description of the instrumentation, a summary of results from flight tests, and discuss potential applications of these instrumented platforms for air-sea-ice interaction studies.

  1. On Ambiguities in SAR Design

    NASA Technical Reports Server (NTRS)

    Freeman, Anthony

    2006-01-01

    Ambiguities are an aliasing effect caused by the periodic sampling of the scene backscatter inherent to pulsed radar systems such as Synthetic Aperture radar (SAR). In this paper we take a fresh look at the relationship between SAR range and azimuth ambiguity constraints on the allowable pulse repetition frequency (PRF) and the antenna length. We show that for high squint angles smaller antennas may be feasible in some cases. For some applications, the ability to form a synthetic aperture at high squint angles is desirable, but the size of the antenna causes problems in the design of systems capable of such operation. This is because the SAR system design is optimized for a side-looking geometry. In two examples design examples we take a suboptimum antenna size and examine the performance in terms of azimuth resolution and swath width as a function of squint angle. We show that for stripmap SARs, the swath width is usually worse for off-boresight squint angles, because it is severely limited by range walk, except in cases where we relax the spatial resolution. We consider the implications for the design of modest-resolution, narrow swath, scanning SAR scatterometers .

  2. Conceptual design of an airborne laser Doppler velocimeter system for studying wind fields associated with severe local storms

    NASA Technical Reports Server (NTRS)

    Thomson, J. A. L.; Davies, A. R.; Sulzmann, K. G. P.

    1976-01-01

    An airborne laser Doppler velocimeter was evaluated for diagnostics of the wind field associated with an isolated severe thunderstorm. Two scanning configurations were identified, one a long-range (out to 10-20 km) roughly horizontal plane mode intended to allow probing of the velocity field around the storm at the higher altitudes (4-10 km). The other is a shorter range (out to 1-3 km) mode in which a vertical or horizontal plane is scanned for velocity (and possibly turbulence), and is intended for diagnostics of the lower altitude region below the storm and in the out-flow region. It was concluded that aircraft flight velocities are high enough and severe storm lifetimes are long enough that a single airborne Doppler system, operating at a range of less than about 20 km, can view the storm area from two or more different aspects before the storm characteristics change appreciably.

  3. An improved MIMO-SAR simulator strategy with ray tracing

    NASA Astrophysics Data System (ADS)

    Xiang, Xingyu; Mo, Zijian; Wang, Zhonghai; Chen, Genshe; Pham, Khanh; Blasch, Erik

    2016-05-01

    High resolution and wide-swath imaging can be obtained by Multiple-Input Multiple-Output (MIMO) synthetic aperture radar (SAR) with the state of the art technologies. The time division multiple access (TDMA) MIMO SAR mimics the motion of the antenna of SAR systems by switching the array channels to transmit the radar signals at different time slots. In this paper, we develop a simulation tool with ray tracing techniques to retrieve high resolution and accurate SAR images for development of MIMO SAR imaging methods. Without loss of generality, in the proposed simulator, we apply a TDMA MIMO SAR system with 13 transmitting antennas and 8 receiving antennas, where all transmitting antennas share a single transmitter and the receiving antennas share a single receiver. By comparing with the normal simulation MIMO SAR strategies, the simulation image using ray tracing results validate that the proposed method provides more accurate and higher resolution SAR images.

  4. A comparative evaluation of SAR and SLAR

    SciTech Connect

    Mastin, G.A.; Manson, J.J.; Bradley, J.D.; Axline, R.M.; Hover, G.L.

    1993-11-01

    Synthetic aperture radar (SAR) was evaluated as a potential technological improvement over the Coast Guard`s existing side-looking airborne radar (SLAR) for oil-spill surveillance applications. The US Coast Guard Research and Development Center (R&D Center), Environmental Branch, sponsored a joint experiment including the US Coast Guard, Sandia National Laboratories, and the Naval Oceanographic and Atmospheric Administration (NOAA), Hazardous Materials Division. Radar imaging missions were flown on six days over the coastal waters off Santa Barbara, CA, where there are constant natural seeps of oil. Both the Coast Guard SLAR and the Sandia National Laboratories SAR were employed to acquire simultaneous images of oil slicks and other natural sea surface features that impact oil-spill interpretation. Surface truth and other environmental data were also recorded during the experiment. The experiment data were processed at Sandia National Laboratories and delivered to the R&D Center on a computer workstation for analysis by experiment participants. Issues such as optimal spatial resolution, single-look vs. multi-look SAR imaging, and the utility of SAR for oil-spill analysis were addressed. Finally, conceptual design requirements for a possible future Coast Guard SAR were outlined and evaluated.

  5. Cognitive Vision and Perceptual Grouping by Production Systems with Blackboard Control - An Example for High-Resolution SAR-Images

    NASA Astrophysics Data System (ADS)

    Michaelsen, Eckart; Middelmann, Wolfgang; Sörgel, Uwe

    The laws of gestalt-perception play an important role in human vision. Psychological studies identified similarity, good continuation, proximity and symmetry as important inter-object relations that distinguish perceptive gestalts from arbitrary sets of clutter objects. Particularly, symmetry and continuation possess a high potential in detection, identification, and reconstruction of man-made objects. This contribution focuses on coding this principle in an automatic production system. Such systems capture declarative knowledge. Procedural details are defined as control strategy for an interpreter. Often an exact solution is not feasible while approximately correct interpretations of the data with the production system are sufficient. Given input data and a production system the control acts accumulatively instead of reducing. The approach is assessment driven features any-time capability and fits well into the recently discussed paradigms of cognitive vision. An example from automatic extraction of groupings and symmetry in man-made structure from high resolution SAR-image data is given. The contribution also discusses the relations of such approach to the "mid-level" of what is today proposed as "cognitive vision".

  6. High-Rate Data-Capture for an Airborne Lidar System

    NASA Technical Reports Server (NTRS)

    Valett, Susan; Hicks, Edward; Dabney, Philip; Harding, David

    2012-01-01

    A high-rate data system was required to capture the data for an airborne lidar system. A data system was developed that achieved up to 22 million (64-bit) events per second sustained data rate (1408 million bits per second), as well as short bursts (less than 4 s) at higher rates. All hardware used for the system was off the shelf, but carefully selected to achieve these rates. The system was used to capture laser fire, single-photon detection, and GPS data for the Slope Imaging Multi-polarization Photo-counting Lidar (SIMPL). However, the system has applications for other laser altimeter systems (waveform-recording), mass spectroscopy, xray radiometry imaging, high-background- rate ranging lidar, and other similar areas where very high-speed data capture is needed. The data capture software was used for the SIMPL instrument that employs a micropulse, single-photon ranging measurement approach and has 16 data channels. The detected single photons are from two sources those reflected from the target and solar background photons. The instrument is non-gated, so background photons are acquired for a range window of 13 km and can comprise many times the number of target photons. The highest background rate occurs when the atmosphere is clear, the Sun is high, and the target is a highly reflective surface such as snow. Under these conditions, the total data rate for the 16 channels combined is expected to be approximately 22 million events per second. For each photon detection event, the data capture software reads the relative time of receipt, with respect to a one-per-second absolute time pulse from a GPS receiver, from an event timer card with 0.1-ns precision, and records that information to a RAID (Redundant Array of Independent Disks) storage device. The relative time of laser pulse firings must also be read and recorded with the same precision. Each of the four event timer cards handles the throughput from four of the channels. For each detection event, a flag is

  7. Wetland InSAR

    NASA Astrophysics Data System (ADS)

    Wdowinski, S.; Kim, S.; Amelung, F.; Dixon, T.

    2006-12-01

    Wetlands are transition zones where the flow of water, the nutrient cycling, and the sun energy meet to produce a unique and very productive ecosystem. They provide critical habitat for a wide variety of plant and animal species, including the larval stages of many ocean fish. Wetlands also have a valuable economical importance, as they filter nutrients and pollutants from fresh water used by human and provide aquatic habitats for outdoor recreation, tourism, and fishing. Globally, many such regions are under severe environmental stress, mainly from urban development, pollution, and rising sea level. However, there is increasing recognition of the importance of these habitats, and mitigation and restoration activities have begun in a few regions. A key element in wetlands conservation, management, and restoration involves monitoring its hydrologic system, as the entire ecosystem depends on its water supply. Heretofore, hydrologic monitoring of wetlands are conducted by stage (water level) stations, which provide good temporal resolution, but suffer from poor spatial resolution, as stage station are typically distributed several, or even tens of kilometers, from one another. Wetland application of InSAR provides the needed high spatial resolution hydrological observations, complementing the high temporal resolution terrestrial observations. Although conventional wisdom suggests that interferometry does not work in vegetated areas, several studies have shown that both L- and C-band interferograms with short acquisition intervals (1-105 days) can maintain excellent coherence over wetlands. In this study we explore the usage of InSAR for detecting water level changes in various wetland environments around the world, including the Everglades (south Florida), Louisiana Coast (southern US), Chesapeake Bay (eastern US), Pantanal (Brazil), Okavango Delta (Botswana), and Lena Delta (Siberia). Our main study area is the Everglades wetland (south Florida), which is covered by

  8. A study to identify and compare airborne systems for in-situ measurements of launch vehicle effluents

    NASA Technical Reports Server (NTRS)

    Thomas, T. J.; Chace, A. S.

    1974-01-01

    An in-situ system for monitoring the concentration of HCl, CO, CO2, and Al2O3 in the cloud of reaction products that form as a result of a launch of solid propellant launch vehicle is studied. A wide array of instrumentation and platforms are reviewed to yield the recommended system. An airborne system suited to monitoring pollution concentrations over urban areas for the purpose of calibrating remote sensors is then selected using a similar methodology to yield the optimal configuration.

  9. Airborne Wind Shear Detection and Warning Systems: Fourth Combined Manufacturers' and Technologists' Conference, part 1

    NASA Technical Reports Server (NTRS)

    Vicroy, Dan D. (Compiler); Bowles, Roland L. (Compiler); Passman, Robert H. (Compiler)

    1992-01-01

    The purpose of the meeting was to transfer significant ongoing results of the NASA/FAA joint Airborne Wind Shear Program to the technical industry and to pose problems of current concern to the combined group. It also provided a forum for manufacturers to review forward-look technology concepts and for technologists to gain an understanding of the problems encountered by the manufacturers during the development of airborne equipment and the FAA certification requirements. The present document was compiled to record the essence of the technology updates and discussions which follow each.

  10. Airborne Wind Shear Detection and Warning Systems. Second Combined Manufacturers' and Technologists' Conference, part 1

    NASA Technical Reports Server (NTRS)

    Spady, Amos A., Jr. (Compiler); Bowles, Roland L. (Compiler); Schlickenmaier, Herbert (Compiler)

    1990-01-01

    The Second Combined Manufacturers' and Technologists' Conference hosted jointly by NASA Langley (LaRC) and the Federal Aviation Administration (FAA) was held in Williamsburg, Virginia, on October 18 to 20, 1988. The purpose of the meeting was to transfer significant, ongoing results gained during the second year of the joint NASA/FAA Airborne Wind Shear Program to the technical industry and to pose problems of current concern to the combined group. It also provided a forum for manufacturers to review forward-look technology concepts and for technologists to gain an understanding of the problems encountered by the manufacturers during the development of airborne equipment and the FAA certification requirements.

  11. Airborne Wind Shear Detection and Warning Systems: Third Combined Manufacturers' and Technologists' Conference, part 2

    NASA Technical Reports Server (NTRS)

    Vicroy, Dan D. (Compiler); Bowles, Roland L. (Compiler); Schlickenmaier, Herbert (Compiler)

    1991-01-01

    The Third Combined Manufacturers' and Technologists' Conference was held in Hampton, Va., on October 16-18, 1990. The purpose of the meeting was to transfer significant on-going results of the NASA/FAA joint Airborne Wind Shear Program to the technical industry and to pose problems of current concern to the combined group. It also provided a forum for manufacturers to review forward-look technology concepts and for technologists to gain an understanding of the problems encountered by the manufacturers during the development of airborne equipment and the FAA certification requirements.

  12. Calibration of dual-frequency SAR ocean imagery

    NASA Technical Reports Server (NTRS)

    Kasischke, E. S.; Larson, R. W.; Lyzenga, D. R.

    1986-01-01

    A calibration procedure for digital aircraft SAR imagery is presented. Techniques to utilize internal and external calibration references are discussed. Examples of calibrated intensity scans from an oceanographic test site are presented. The relationship of the aircraft SAR calibration procedure to future spaceborne SAR systems is discussed.

  13. Classification of Targets in SAR Images Using ISAR Data

    DTIC Science & Technology

    2005-05-01

    Classification of Targets in SAR Images Using ISAR Data J. J. M. de Wit, R. J. Dekker, and A. C. van den Broek TNO Defence, Security, and Safety...classification of targets in SAR images by using ISAR measurements was studied, based on polarimetric SAR and ISAR data acquired with the MEMPHIS...interest in synthetic aperture radar ( SAR ) systems is increasing as well, mainly due to their all-weather capability. A study for the Dutch Ministry of

  14. Polar format algorithm for SAR imaging with Matlab

    NASA Astrophysics Data System (ADS)

    Deming, Ross; Best, Matthew; Farrell, Sean

    2014-06-01

    Due to its computational efficiency, the polar format algorithm (PFA) is considered by many to be the workhorse for airborne synthetic aperture radar (SAR) imaging. PFA is implemented in spatial Fourier space, also known as "K-space", which is a convenient domain for understanding SAR performance metrics, sampling requirements, etc. In this paper the mathematics behind PFA are explained and computed examples are presented, both using simulated data, and experimental airborne radar data from the Air Force Research Laboratory (AFRL) Gotcha Challenge collect. In addition, a simple graphical method is described that can be used to model and predict wavefront curvature artifacts in PFA imagery, which are due to the limited validity of the underlying far-field approximation. The appendix includes Matlab code for computing SAR images using PFA.

  15. X-SAR as high-performance interferometric SAR

    NASA Astrophysics Data System (ADS)

    Werner, Marian U.; Schandl, Josef

    1995-11-01

    In April and October 1994 the X-SAR radar has been flown twice onboard the Space Shuttle, as part of the Space Radar Laboratory (SRL-1 and SRL-2). This radar payload is the first synthetic aperture radar (SAR) system of its kind in space, with three frequencies, multi- polarization, variable incidence angle and variable modes of operation. SIR-C/X-SAR, the new generation of imaging microwave remote sensing sensors from space, demonstrated successfully repeat pass interferometry in all three frequencies with a one day repeat as well as a six month repeat orbit. The major problems with the repeat orbit interferometry are the temporal target decorrelation, unsuitable baseline and different squint angles for the two passes to be processed. Therefore, for the third mission of the Space Radar Lab which shall be called SRTM (shuttle radar topographic mapper), single pass interferometry with a second receive antenna is proposed to generate a topographic map of all land surfaces between +60 degrees and -56 degrees latitude. X-SAR's 12 meter long and 40 cm wide main transmit and receive antenna is mounted directly to a tiltable part of the SIR-C antenna truss structure in the Shuttle cargo bay. The second receive antenna is 6 meters long and is mounted together with the second C-band antenna to a 31 meter long deployable boom structure perpendicular to the velocity direction to build the baseline. X-SAR is not capable of operating in a scan SAR model like SIR-C to allow continuous coverage, but will operate in a high resolution mode with a swath width of 30 - 35 km. The engineering design of the interferometric configuration for X-SAR, the requirement specifications, and the predicted performance as well as the mission operation aspects are described in this paper. SIR-C/X- SAR is a cooperative project. The SIR-C instrument was developed by NASA's Jet Propulsion Laboratory (JPL). The X-band radar (X-SAR) was developed by the Dornier and Alenia Spazio Companies for the German

  16. A Performance Assessment of an Airborne Separation Assistance System Using Realistic Complex Traffic Flows

    NASA Technical Reports Server (NTRS)

    Smith, Jeremy C.; Bussink, Frank J. L.

    2008-01-01

    This paper presents the results from a study that investigates the performance of a tactical Airborne Separation Assistance System (ASAS) in en route airspace, under varying demand levels, with realistic traffic flows. The ASAS concept studied here allows flight crews of equipped aircraft to perform separation from other air traffic autonomously. This study addresses the tactical aspects of an ASAS using aircraft state data (i.e. position and velocity) to detect and resolve projected conflicts. In addition, use of a conflict prevention system helps ASAS-equipped aircraft avoid maneuvers that may cause new conflicts. ASAS-capable aircraft are equipped with satellite-based navigation and Automatic Dependent Surveillance Broadcast (ADS-B) for transmission and receipt of aircraft state data. In addition to tactical conflict detection and resolution (CD&R), a complete, integrated ASAS is likely to incorporate a strategic CD&R component with a longer look-ahead time, using trajectory intent information. A system-wide traffic flow management (TFM) component, located at the FAA command center helps aircraft to avoid regions of excessive traffic density and complexity. A Traffic Alert and Collision Avoidance System (TCAS), as used today is the system of last resort. This integrated approach avoids sole reliance on the use of the tactical CD&R studied here, but the tactical component remains a critical element of the complete ASAS. The focus of this paper is to determine to what extent the proposed tactical component of ASAS alone can maintain aircraft separation at demand levels up to three times that of current traffic. The study also investigates the effect of mixing ASAS-equipped aircraft with unequipped aircraft (i.e. current day) that do not have the capability to self-separate. Position and velocity data for unequipped aircraft needs to be available to ASASequipped. Most likely, for this future concept, state data would be available from instrument flight rules (IFR

  17. Biooptical variability in the Greenland Sea observed with the Multispectral Airborne Radiometer System (MARS)

    NASA Technical Reports Server (NTRS)

    Mueller, James L.; Trees, Charles C.

    1989-01-01

    A site-specific ocean color remote sensing algorithm was developed and used to convert Multispectral Airborne Radiometer System (MARS) spectral radiance measurements to chlorophyll-a concentration profiles along aircraft tracklines in the Greenland Sea. The analysis is described and the results given in graphical or tabular form. Section 2 describes the salient characteristics and history of development of the MARS instrument. Section 3 describes the analyses of MARS flight segments over consolidated sea ice, resulting in a set of altitude dependent ratios used (over water) to estimate radiance reflected by the surface and atmosphere from total radiance measured. Section 4 presents optically weighted pigment concentrations calculated from profile data, and spectral reflectances measured in situ from the top meter of the water column; this data was analyzed to develop an algorithm relating chlorophyll-a concentrations to the ratio of radiance reflectances at 441 and 550 nm (with a selection of coefficients dependent upon whether significant gelvin presence is implied by a low ratio of reflectances at 410 and 550 nm). Section 5 describes the scaling adjustments which were derived to reconcile the MARS upwelled radiance ratios at 410:550 nm and 441:550 nm to in situ reflectance ratios measured simultaneously on the surface. Section 6 graphically presents the locations of MARS data tracklines and positions of the surface monitoring R/V. Section 7 presents stick-plots of MARS tracklines selected to illustrate two-dimensional spatial variability within the box covered by each day's flight. Section 8 presents curves of chlorophyll-a concentration profiles derived from MARS data along survey tracklines. Significant results are summarized in Section 1.

  18. Development of a satellite SAR image spectra and altimeter wave height data assimilation system for ERS-1

    NASA Technical Reports Server (NTRS)

    Hasselmann, Klaus; Hasselmann, Susanne; Bauer, Eva; Bruening, Claus; Lehner, Susanne; Graber, Hans; Lionello, Piero

    1988-01-01

    The applicability of ERS-1 wind and wave data for wave models was studied using the WAM third generation wave model and SEASAT altimeter, scatterometer and SAR data. A series of global wave hindcasts is made for the surface stress and surface wind fields by assimilation of scatterometer data for the full 96-day SEASAT and also for two wind field analyses for shorter periods by assimilation with the higher resolution ECMWF T63 model and by subjective analysis methods. It is found that wave models respond very sensitively to inconsistencies in wind field analyses and therefore provide a valuable data validation tool. Comparisons between SEASAT SAR image spectra and theoretical SAR spectra derived from the hindcast wave spectra by Monte Carlo simulations yield good overall agreement for 32 cases representing a wide variety of wave conditions. It is concluded that SAR wave imaging is sufficiently well understood to apply SAR image spectra with confidence for wave studies if supported by realistic wave models and theoretical computations of the strongly nonlinear mapping of the wave spectrum into the SAR image spectrum. A closed nonlinear integral expression for this spectral mapping relation is derived which avoids the inherent statistical errors of Monte Carlo computations and may prove to be more efficient numerically.

  19. Orchitis: a complication of severe acute respiratory syndrome (SARS).

    PubMed

    Xu, Jian; Qi, Lihua; Chi, Xiaochun; Yang, Jingjing; Wei, Xiaohong; Gong, Encong; Peh, Suatcheng; Gu, Jiang

    2006-02-01

    Severe acute respiratory syndrome (SARS) coronavirus has been known to damage multiple organs; however, little is known about its impact on the reproductive system. In the present study, we analyzed the pathological changes of testes from six patients who died of SARS. Results suggested that SARS caused orchitis. All SARS testes displayed widespread germ cell destruction, few or no spermatozoon in the seminiferous tubule, thickened basement membrane, and leukocyte infiltration. The numbers of CD3+ T lymphocytes and CD68+ macrophages increased significantly in the interstitial tissue compared with the control group (P < 0.05). SARS viral genomic sequences were not detected in the testes by in situ hybridization. Immunohistochemistry demonstrated abundant IgG precipitation in the seminiferous epithelium of SARS testes, indicating possible immune response as the cause for the damage. Our findings indicated that orchitis is a complication of SARS. It further suggests that the reproductive functions should be followed and evaluated in recovered male SARS patients.

  20. SAR imagery using chaotic carrier frequency agility pulses

    NASA Astrophysics Data System (ADS)

    Xu, Xiaojian; Feng, Xiangzhi

    2011-06-01

    Synthetic aperture radar (SAR) systems are getting more and more applications in both civilian and military remote sensing missions. With the increasing deployment of electronic countermeasures (ECM) on modern battlefields, SAR encounters more and more interference jamming signals. The ECM jamming signals cause the SAR system to receive and process erroneous information which results in severe degradations in the output SAR images and/or formation of phony images of nonexistent targets. As a consequence, development of the electronic counter-countermeasures (ECCM) capability becomes one of the key problems in SAR system design. This paper develops radar signaling strategies and algorithms that enhance the ability of synthetic aperture radar to image targets under conditions of electronic jamming. The concept of SAR using chaotic carrier frequency agility pulses (CCFAP-SAR) is first proposed. Then the imaging procedure for CCFAP-SAR is discussed in detail. The ECCM performance of CCFAP-SAR for both depressive noise jamming and deceptive repeat jamming is analyzed. The impact of the carrier frequency agility range on the image quality of CCFAP-SAR is also studied. Simulation results demonstrate that, with adequate agility range of the carrier frequency, the proposed CCFAP-SAR performs as well as conventional radar with linear frequency modulation (LFM) waveform in image quality and slightly better in anti-noise depressive jamming; while performs very well in anti-deception jamming which cannot be rejected by LFM-SAR.

  1. Low cost realization of space-borne synthectic aperture radar - MicroSAR

    NASA Astrophysics Data System (ADS)

    Carter, D.; Hall, C.

    Spaceborne Earth Observation data has been used for decades in the areas of meteorology and optical imaging. The systems and satellites have, in the main, been owned and operated by a few government institutions and agencies. More recently industrial organizations in North America have joined the list. Few of these, however, include Synthetic Aperture Radar (SAR)., although the additional utility in terms of all weather, 24 hour measurement capability over the Earth's surface is well recognized. Three major factors explain this:1) Relationships between the SAR measurements of radar backscatter and images to the specific information needs have not been seen as sufficiently well understood or robust2) Availability of suitable sources, at the relevant performance and data quality have been inadequate to provide service assurance that is necessary to sustain commercial businesses3) Costs associated with building, launching and operating spaceborne SAR have not been low enough as to achieve an acceptable return of investment. A significant amount of research and development has been undertaken throughout the World to establish reliable and robust algorithms for information extraction from SAR data. Much of this work has been carried out utilizing airborne systems over localized and carefully controlled regions. In addition, an increasing number of pilot services have been offered by geo-information providers. This has allowed customer confidence to grow. With the status of spaceborne SAR being effectively in the development phase, commercial funding has been scarce, and there has been need to rely on government and institutional budgets. Today the increasing maturity of the technology of SAR and its applications is beginning to attract the commercial sector. This is the funding necessary to realize sufficient assets to be able to provide a robust supply of SAR data to the geo-information providers and subsequently a reliable service to customers. Reducing the costs

  2. Imaging Hidden Water in Three Dimensions Using an Active Airborne Electromagnetic System

    NASA Astrophysics Data System (ADS)

    Wynn, J.

    2001-05-01

    The San Pedro Basin aquifer in southeastern Arizona and northern Mexico is important not only for local agriculture and residential communities, but also because it is the source of the San Pedro River. Declared a Riparian Conservation Area by Congress in 1988, the San Pedro is a critical element of one of four major migratory bird fly-ways over North America. The basin crosses the international frontier, extending into northern Mexico, where about 12,000 acre-ft of water is withdrawn yearly by the Cananea Mine. An additional 11,000 acre-ft is withdrawn by the US Army base at Fort Huachuca and surrounding towns including Sierra Vista. About 6,000 to 8,000 acre-ft of water is also estimated as lost to evapotranspiration, while recharge (mainly from the Huachuca Mountains) ranges from 12,500 to 15,000 acre-ft per year. This apparent net deficit is considered a serious threat by environmental groups to the integrity of the Riparian Conservation Area. Efforts have been underway to develop catchments and to implement water-conservation measures, but these have been hampered by a lack of detailed knowledge of the three-dimensional geometry and extent of the aquifer beneath the entire basin - at least until recently. In an effort to identify subcomponents and interconnectivities within the San Pedro Basin aquifer, the US Army funded several airborne EM surveys, conducted in 1997 and 1999 under the supervision of the US Geological Survey east of Fort Huachuca. These surveys used the Geoterrex GEOTEM system with 20 gated time-domain windows in three perpendicular orientations. The 60+ channel information was inverted using two different methods into conductivity-depth transforms, i.e., conductivity vs. depth along each flight-line. The resulting inversions have been assembled into a three-dimensional map of the aquifer, which in this arid region is quite conductive (the average is 338 micro-S/cm, around 30 ohm-meters). The coverage is about 1,000 square kilometers down to a

  3. Feasibility of inter-comparing airborne and spaceborne observations of radar backscattering coefficients

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This paper investigates the feasibility of using an airborne synthetic aperture radar (SAR) to validate spaceborne SAR data. This is directed at soil moisture sensing and the recently launched Soil Moisture Active Passive (SMAP) satellite. The value of this approach is related to the fact that vicar...

  4. Efficiency calibration and minimum detectable activity concentration of a real-time UAV airborne sensor system with two gamma spectrometers.

    PubMed

    Tang, Xiao-Bin; Meng, Jia; Wang, Peng; Cao, Ye; Huang, Xi; Wen, Liang-Sheng; Chen, Da

    2016-04-01

    A small-sized UAV (NH-UAV) airborne system with two gamma spectrometers (LaBr3 detector and HPGe detector) was developed to monitor activity concentration in serious nuclear accidents, such as the Fukushima nuclear accident. The efficiency calibration and determination of minimum detectable activity concentration (MDAC) of the specific system were studied by MC simulations at different flight altitudes, different horizontal distances from the detection position to the source term center and different source term sizes. Both air and ground radiation were considered in the models. The results obtained may provide instructive suggestions for in-situ radioactivity measurements of NH-UAV.

  5. Photometer dewar system for NASA C141 airborne telescope (Kuiper Flying Observatory). [design analysis/performance tests

    NASA Technical Reports Server (NTRS)

    Ney, E. P.

    1974-01-01

    The design, calibration, and testing of a photometer to be used in an airborne telescope is described. A description of the cryogenics of the photometer is given, and photographs and blueprints of the photometer are included. The photometer is designed with a focal plane beam switching system so that the airplane telescope can be used in a normal optical mode at the bent Cassegrain focus and with the photometer operating in the pressurized cabin of the airplane. The concept was to produce a system which could be used in almost the same manner as ground based infrared photometers and dewars of the O'Brien Observatory at the University of Minnesota.

  6. InfoTerra/TerraSAR initiative

    NASA Astrophysics Data System (ADS)

    Wahl, Manfred W.

    2004-01-01

    The overarching goal of the InfoTerra/TerraSAR Initiative is to establish a self-sustaining operational/commercial business built on Europe"s know-how and experience in space-borne Synthetic Aperture Radar (SAR) technology, in SAR data processing as well as in SAR applications. InfoTerra stands for a new business concept based on supplying innovative geo-information products and services. TerraSAR is a space and ground system conceived to consist of an initial deployment and operation of 2 Radar satellites (one in X- and one in L-band) flying in a tandem configuration in the same orbit. The design of TerraSAR is driven by the market and is user-oriented. TerraSAR is key to capturing a significant proportion of the existing market and to opening new market opportunities, when it becomes operational. The InfoTerra/TerraSAR Initiative has evolved gradually. It started in 1997 as a joint venture between German (DSS) and British (MMS-UK) space industry, strongly supported by both space agencies, DLR and BNSC. In early 2001, DLR and BNSC submitted to ESA the Formal Programme Proposal for InfoTerra/TerraSAR to become an essential element of ESA"s Earth Watch Programme. In summer 2001, when it became evident that there was not yet sufficient support from the ESA Member States to allow immediate start entering into TerraSAR Phase C/D, it has been decided to implement first a TerraSAR consolidation phase. In early 2002, in order to avoid further delays, a contract was signed between DLR and Astrium GmbH on the development of one component of TerraSAR, the TerraSAR-X, in the frame of a national programme, governed by a Public Private Partnership Agreement. Even if now the different launch dates for TerraSAR-X and TerraSAR-L are narrowing down the window of common data acquisition, it is a reasonable starting point, but it should always be kept in mind that the utmost goal for the longterm is to achieve self sustainability by supplying geo-information products and services

  7. 20. OVERVIEW OF SAR3 COMPLEX, SHOWING FORMER RESIDENTIAL AREA, SAR3 ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    20. OVERVIEW OF SAR-3 COMPLEX, SHOWING FORMER RESIDENTIAL AREA, SAR-3 SWITCH RACK, MAINTENANCE YARD, AND GREENSPOT BRIDGE. NOTE ALSO LARGE PIPE CONDUCTING TAILRACE WATER INTO IRRIGATION SYSTEM. VIEW TO SOUTHWEST. - Santa Ana River Hydroelectric System, Redlands, San Bernardino County, CA

  8. Enhanced resolution in Sar/ISAR imaging using iterative sidelobe apodization.

    PubMed

    Xu, Xiaojian; Narayanan, Ram M

    2005-04-01

    Resolution enhancement techniques in radar imaging have attracted considerable interest in recent years. In this work, we develop an iterative sidelobe apodization technique and investigate its applications to synthetic aperture radar (SAR) and inverse SAR (ISAR) image processing. A modified noninteger Nyquist spatially variant apodization (SVA) formulation is proposed, which is applicable to direct iterative image sidelobe apodization without using computationally intensive upsampling interpolation. A refined iterative sidelobe apodization procedure is then developed for image-resolution enhancement. Examples using this technique demonstrate enhanced image resolution in various applications, including airborne SAR imaging, image processing for three-dimensional interferometric ISAR imaging, and foliage-penetration ultrawideband SAR image processing.

  9. An application of space-time adaptive processing to airborne and spaceborne monostatic and bistatic radar systems

    NASA Astrophysics Data System (ADS)

    Czernik, Richard James

    A challenging problem faced by Ground Moving Target Indicator (GMTI) radars on both airborne and spaceborne platforms is the ability to detect slow moving targets due the presence of non-stationary and heterogeneous ground clutter returns. Space-Time Adaptive Processing techniques process both the spatial signals from an antenna array as well as radar pulses simultaneously to aid in mitigating this clutter which has an inherent Doppler shift due to radar platform motion, as well as spreading across Angle-Doppler space attributable to a variety of factors. Additional problems such as clutter aliasing, widening of the clutter notch, and range dependency add additional complexity when the radar is bistatic in nature, and vary significantly as the bistatic radar geometry changes with respect to the targeted location. The most difficult situation is that of a spaceborne radar system due to its high velocity and altitude with respect to the earth. A spaceborne system does however offer several advantages over an airborne system, such as the ability to cover wide areas and to provide access to areas denied to airborne platforms. This dissertation examines both monostatic and bistatic radar performance based upon a computer simulation developed by the author, and explores the use of both optimal STAP and reduced dimension STAP architectures to mitigate the modeled clutter returns. Factors such as broadband jamming, wind, and earth rotation are considered, along with their impact on the interference covariance matrix, constructed from sample training data. Calculation of the covariance matrix in near real time based upon extracted training data is computer processor intensive and reduced dimension STAP architectures relieve some of the computation burden. The problems resulting from extending both monostatic and bistatic radar systems to space are also simulated and studied.

  10. SAR change detection MTI

    NASA Astrophysics Data System (ADS)

    Scarborough, Steven; Lemanski, Christopher; Nichols, Howard; Owirka, Gregory; Minardi, Michael; Hale, Todd

    2006-05-01

    This paper examines the theory, application, and results of using single-channel synthetic aperture radar (SAR) data with Moving Reference Processing (MRP) to focus and geolocate moving targets. Moving targets within a standard SAR imaging scene are defocused, displaced, or completely missing in the final image. Building on previous research at AFRL, the SAR-MRP method focuses and geolocates moving targets by reprocessing the SAR data to focus the movers rather than the stationary clutter. SAR change detection is used so that target detection and focusing is performed more robustly. In the cases where moving target returns possess the same range versus slow-time histories, a geolocation ambiguity results. This ambiguity can be resolved in a number of ways. This paper concludes by applying the SAR-MRP method to high-frequency radar measurements from persistent continuous-dwell SAR observations of a moving target.

  11. Dual super-systolic core for real-time reconstructive algorithms of high-resolution radar/SAR imaging systems.

    PubMed

    Atoche, Alejandro Castillo; Castillo, Javier Vázquez

    2012-01-01

    A high-speed dual super-systolic core for reconstructive signal processing (SP) operations consists of a double parallel systolic array (SA) machine in which each processing element of the array is also conceptualized as another SA in a bit-level fashion. In this study, we addressed the design of a high-speed dual super-systolic array (SSA) core for the enhancement/reconstruction of remote sensing (RS) imaging of radar/synthetic aperture radar (SAR) sensor systems. The selected reconstructive SP algorithms are efficiently transformed in their parallel representation and then, they are mapped into an efficient high performance embedded computing (HPEC) architecture in reconfigurable Xilinx field programmable gate array (FPGA) platforms. As an implementation test case, the proposed approach was aggregated in a HW/SW co-design scheme in order to solve the nonlinear ill-posed inverse problem of nonparametric estimation of the power spatial spectrum pattern (SSP) from a remotely sensed scene. We show how such dual SSA core, drastically reduces the computational load of complex RS regularization techniques achieving the required real-time operational mode.

  12. Dual Super-Systolic Core for Real-Time Reconstructive Algorithms of High-Resolution Radar/SAR Imaging Systems

    PubMed Central

    Atoche, Alejandro Castillo; Castillo, Javier Vázquez

    2012-01-01

    A high-speed dual super-systolic core for reconstructive signal processing (SP) operations consists of a double parallel systolic array (SA) machine in which each processing element of the array is also conceptualized as another SA in a bit-level fashion. In this study, we addressed the design of a high-speed dual super-systolic array (SSA) core for the enhancement/reconstruction of remote sensing (RS) imaging of radar/synthetic aperture radar (SAR) sensor systems. The selected reconstructive SP algorithms are efficiently transformed in their parallel representation and then, they are mapped into an efficient high performance embedded computing (HPEC) architecture in reconfigurable Xilinx field programmable gate array (FPGA) platforms. As an implementation test case, the proposed approach was aggregated in a HW/SW co-design scheme in order to solve the nonlinear ill-posed inverse problem of nonparametric estimation of the power spatial spectrum pattern (SSP) from a remotely sensed scene. We show how such dual SSA core, drastically reduces the computational load of complex RS regularization techniques achieving the required real-time operational mode. PMID:22736964

  13. Airborne forward-pointing UV Rayleigh lidar for remote clear air turbulence detection: system design and performance.

    PubMed

    Vrancken, Patrick; Wirth, Martin; Ehret, Gerhard; Barny, Hervé; Rondeau, Philippe; Veerman, Henk

    2016-11-10

    A high-performance airborne UV Rayleigh lidar system was developed within the European project DELICAT. With its forward-pointing architecture, it aims at demonstrating a novel detection scheme for clear air turbulence (CAT) for an aeronautics safety application. Due to its occurrence in clear and clean air at high altitudes (aviation cruise flight level), this type of turbulence evades microwave radar techniques and in most cases coherent Doppler lidar techniques. The present lidar detection technique relies on air density fluctuation measurement and is thus independent of backscatter from hydrometeors and aerosol particles. The subtle air density fluctuations caused by the turbulent air flow demand exceptionally high stability of the setup and in particular of the detection system. This paper describes an airborne test system for the purpose of demonstrating this technology and turbulence detection method: a high-power UV Rayleigh lidar system is installed on a research aircraft in a forward-looking configuration for use in cruise flight altitudes. Flight test measurements demonstrate this unique lidar system being able to resolve air density fluctuations occurring in light-to-moderate CAT at 5 km or moderate CAT at 10 km distance. A scaling of the determined stability and noise characteristics shows that such performance is adequate for an application in commercial air transport.

  14. Establishment of Airborne Nanoparticle Exposure Chamber System to Assess Nano TiO2 Induced Mice Lung Effects

    NASA Astrophysics Data System (ADS)

    Chen, Chia-Hua; Li, Jui-Ping; Huang, Nai-Chun; Yang, Chung-Shi; Chen, Jen-Kun

    2011-12-01

    A great many governments have schemed their top priority to support the research and development of emerging nanotechnology, which lead to increasing products containing nanomaterials. However, platforms and protocols to evaluate the safety of nanomaterials are not yet established. We therefore design and fabricate a nanoparticle exposure chamber system (NECS) and try to standardize protocols to assess potential health risk of inhalable nanoparticles. This platform comprises: (1) nano-aerosol generators to produce homogeneous airborne nanoparticles, (2) double isolated container to prevent from unexpected exposure to humans, (3) gas supply system for housing animals or incubating cultured cells, and (4) system for automatic control and airborne nanoparticle analysis. The NECS providing multiple functions includes: (1) a secure environment to handle nanomaterials, (2) real-time measurement for the size and distribution of airborne nanoparticles, (3) SOP of safety evaluation for nanomaterials, and (4) key technology for the development of inhalable pharmaceuticals. We used NECS to mimic occupational environment for exploring potential adverse effects of TiO2 nanoparticles. The adult male ICR mice were exposed to 25nm, well-characterized TiO2 particles for 1 and 4 weeks. More than 90% of the inhaled TiO2 nanoparticles deposit in lung tissue, which tends to be captured by alveolar macrophages. Pulmonary function test does not show significant physiological changes between one and 4 weeks exposure. For plasma biochemistry analysis, there are no obvious inflammation responses after exposure for one and 4 weeks; however, disruption of alveolar septa and increased thickness of alveolar epithelial cells were observed. According to our results, the NECS together with our protocols show comprehensive integration and ideally fit the standard of OECD guildelines-TG403, TG412, TG413; it can be further customized to fulfill diverse demands of industry, government, and third party

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

    NASA Astrophysics Data System (ADS)

    Sahawneh, Laith Rasmi

    The increasing demand to integrate unmanned aircraft systems (UAS) into the national airspace is motivated by the rapid growth of the UAS industry, especially small UAS weighing less than 55 pounds. Their use however has been limited by the Federal Aviation Administration regulations due to collision risk they pose, safety and regulatory concerns. Therefore, before civil aviation authorities can approve routine UAS flight operations, UAS must be equipped with sense-and-avoid technology comparable to the see-and-avoid requirements for manned aircraft. The sense-and-avoid problem includes several important aspects including regulatory and system-level requirements, design specifications and performance standards, intruder detecting and tracking, collision risk assessment, and finally path planning and collision avoidance. In this dissertation, our primary focus is on developing an collision detection, risk assessment and avoidance framework that is computationally affordable and suitable to run on-board small UAS. To begin with, we address the minimum sensing range for the sense-and-avoid (SAA) system. We present an approximate close form analytical solution to compute the minimum sensing range to safely avoid an imminent collision. The approach is then demonstrated using a radar sensor prototype that achieves the required minimum sensing range. In the area of collision risk assessment and collision prediction, we present two approaches to estimate the collision risk of an encounter scenario. The first is a deterministic approach similar to those been developed for Traffic Alert and Collision Avoidance (TCAS) in manned aviation. We extend the approach to account for uncertainties of state estimates by deriving an analytic expression to propagate the error variance using Taylor series approximation. To address unanticipated intruders maneuvers, we propose an innovative probabilistic approach to quantify likely intruder trajectories and estimate the probability of

  16. Recovering Seasat SAR Data

    NASA Astrophysics Data System (ADS)

    Logan, T. A.; Arko, S. A.; Rosen, P. A.

    2013-12-01

    To demonstrate the feasibility of orbital remote sensing for global ocean observations, NASA launched Seasat on June 27th, 1978. Being the first space borne SAR mission, Seasat produced the most detailed SAR images of Earth from space ever seen to that point in time. While much of the data collected in the USA was processed optically, a mere 150 scenes had been digitally processed by March 1980. In fact, only an estimated 3% of Seasat data was ever digitally processed. Thus, for over three decades, the majority of the SAR data from this historic mission has been dormant, virtually unavailable to scientists in the 21st century. Over the last year, researchers at the Alaska Satellite Facility (ASF) Distributed Active Archive Center (DAAC) have processed the Seasat SAR archives into imagery products. A telemetry decoding system was created and the data were filtered into readily processable signal files. Due to nearly 35 years of bit rot, the bit error rate (BER) for the ASF DAAC Seasat archives was on the order of 1 out of 100 to 1 out of 100,000. This extremely high BER initially seemed to make much of the data undecodable - because the minor frame numbers are just 7 bits and no range line numbers exist in the telemetry even the 'simple' tasks of tracking the minor frame number or locating the start of each range line proved difficult. Eventually, using 5 frame numbers in sequence and a handful of heuristics, the data were successfully decoded into full range lines. Concurrently, all metadata were stored into external files. Recovery of this metadata was also problematic, the BER making the information highly suspect and, initially at least, unusable in any sort of automated fashion. Because of the BER, all of the single bit metadata fields proved unreliable. Even fields that should be constant for a data take (e.g. receiving station, day of the year) showed high variability, each requiring a median filter to be usable. The most challenging, however, were the

  17. Advanced InSAR and GPS measurements for the detection of surface movements along the Alto Tiberina (Italy) normal fault system: data modeling and future perspectives

    NASA Astrophysics Data System (ADS)

    Anderlini, L.; Polcari, M.; Bignami, C.; Pepe, A.; Solaro, G.; Serpelloni, E.; Moro, M.; Albano, M.; Chiaraluce, L.; Stramondo, S.

    2014-12-01

    The Alto Tiberina fault (ATF) is a low-angle (east-dipping at 15°), 70 km long normal fault (LANF) located in the Umbria-Marche Apennines (central Italy), an area characterized by a SW-NE oriented extension occurring at rates of ~2 mm/yr. Active extension is precisely measured by a dense distribution of GPS stations belonging to several networks, thanks also to additional sites recently installed in the framework of the INGV national RING network and of the ATF observatory. Advanced Interferometry SAR (A-InSAR) techniques play today a key role in Earth Sciences thanks to their capability to detect and monitor slow surface movements over wide areas. A-InSAR techniques, along with in-situ ground measurements, can provide suitable information on the causes of interseismic (seismic, creep) movements. Large datasets of SAR images of European (ERS 1-2 and ENVISAT) and Italian (COSMO-SKyMed) satellites have been used to retrieve surface velocity maps and relevant time series from 1992 to 2014, along both ascending and descending orbits. A network of artificial Corner Reflectors has also been deployed in the proximity of some GPS sites in order to calibrate the processing results of the COSMO-SkyMed SAR data-set and to derive velocity maps. We use an elastic Block Modeling (BM) approach in order to model GPS data by considering the major fault systems as bounds of rotating blocks, while estimating geodetic fault slip-rates.,Thanks to the latest imaging of its deep structure obtained from seismic profiles, the ATF is represented as a complex rough surface with the goal of evaluating the distribution of interseismic fault coupling. The preliminary results obtained show firstly that the observed extension is partially accommodated by interseismic deformation on the ATF, highlighting the important role of this LANF inside an active tectonic contest. Secondarily, using the ATF surface "topography", we found for the resolved areas an interesting correlation between

  18. Airborne Wind Shear Detection and Warning Systems. Second Combined Manufacturers' and Technologists' Conference, part 2

    NASA Technical Reports Server (NTRS)

    Spady, Amos A., Jr. (Compiler); Bowles, Roland L. (Compiler); Schlickenmaier, Herbert (Compiler)

    1990-01-01

    The Second Combined Manufacturers' and Technologists' Conference was hosted jointly by NASA Langley (LaRC) and the Federal Aviation Administration (FAA) in Williamsburg, Virginia, on October 18 to 20, 1988. The meeting was co-chaired by Dr. Roland Bowles of LaRC and Herbrt Schlickenmaier of the FAA. The purpose of the meeting was to transfer significant, ongoing results gained during the second year of the joint NASA/FAA Airborne Wind Shear Program to the technical industry and to pose problems of current concern to the combined group. It also provided a forum for manufacturers to review forward-look technology concepts and for technologists to gain an understanding of the problems encountered by the manufacturers during the development of airborne equipment and the FAA certification requirements.

  19. Airborne Wind Shear Detection and Warning Systems. Fourth Combined Manufacturers' and Technologists' Conference, part 2

    NASA Technical Reports Server (NTRS)

    Vicroy, Dan D. (Compiler); Bowles, Roland L. (Compiler); Passman, Robert H. (Compiler)

    1992-01-01

    The Fourth Combined Manufacturers' and Technologists' Conference was hosted jointly by NASA Langley Research Center (LaRC) and the Federal Aviation Administration (FAA) in Williamsburg, Virginia, on April 14-16, 1992. The meeting was co-chaired by Dr. Roland Bowles of LaRC and Bob Passman of the FAA. The purpose of the meeting was to transfer significant ongoing results of the NASA/FAA Joint Airborne Wind Shear Program to the technical industry and to pose problems of current concern to the combined group. It also provided a forum for manufacturers to review forward-look technology concepts and for technologists to gain an understanding of the problems encountered by the manufacturers during the development of airborne equipment and the FAA certification requirements. The present document has been compiled to record the essence of the technology updates and discussions which follow each.

  20. Interface of a particle collector with on-line electrochemically-modulated separation system for analysis of airborne radioisotopes

    SciTech Connect

    Duckworth, Douglas {Doug} C

    2005-01-01

    The International Monitoring System is part of the global verification system of the Comprehensive Nuclear-Test-Ban Treaty and comprises an atmospheric radioactivity monitoring network of 80 particulate stations, 40 of which are to be equipped with noble-gas-detection capability. The network is supported by 16 radionuclide laboratories. The equipment has to be tailored to different environments and its reliability is proving to be an operational challenge. A novel device for collecting, concentrating and separating airborne particles in situ is under development through a collaborative effort between Savannah River Technology Center (SRTC) and Oak Ridge National Laboratory (ORNL). This work entails coupling an Aerosol-to-Liquid Particle Extraction System (ALPES) to an electrochemically modulated separation (EMS) cell. The ALPES collects and concentrates airborne particles into a liquid, and the EMS cell separates species based on their affinity for a charged target surface. Preliminary data indicates substantial sensitivity enhancement may be realized by interfacing these devices. The system will allow for rapid field analysis of radionuclides while providing reductions in labor, cost, and turnaround time compared to standard radiometric techniques.

  1. Crop monitoring & yield forecasting system based on Synthetic Aperture Radar (SAR) and process-based crop growth model: Development and validation in South and South East Asian Countries

    NASA Astrophysics Data System (ADS)

    Setiyono, T. D.

    2014-12-01

    Accurate and timely information on rice crop growth and yield helps governments and other stakeholders adapting their economic policies and enables relief organizations to better anticipate and coordinate relief efforts in the wake of a natural catastrophe. Such delivery of rice growth and yield information is made possible by regular earth observation using space-born Synthetic Aperture Radar (SAR) technology combined with crop modeling approach to estimate yield. Radar-based remote sensing is capable of observing rice vegetation growth irrespective of cloud coverage, an important feature given that in incidences of flooding the sky is often cloud-covered. The system allows rapid damage assessment over the area of interest. Rice yield monitoring is based on a crop growth simulation and SAR-derived key information, particularly start of season and leaf growth rate. Results from pilot study sites in South and South East Asian countries suggest that incorporation of SAR data into crop model improves yield estimation for actual yields. Remote-sensing data assimilation into crop model effectively capture responses of rice crops to environmental conditions over large spatial coverage, which otherwise is practically impossible to achieve. Such improvement of actual yield estimates offers practical application such as in a crop insurance program. Process-based crop simulation model is used in the system to ensure climate information is adequately captured and to enable mid-season yield forecast.

  2. Airborne and Maritime/Fixed Station Joint Tactical Radio System (AMF JTRS)

    DTIC Science & Technology

    2015-12-01

    multi- band, multi-mode, mobile ad hoc networking radios, providing simultaneous voice and data communications for Army aviation platforms. The radios...services to the platform, and connecting Army aviation platforms to Army ground and Joint air network domains. AMF will procure the Small Airborne...requirements as validated by the Army aviation community. SANR will provide increased data throughput to Army aviation platforms via the Soldier Radio Waveform

  3. Unmanned Airborne System Deployment at Turrialba Volcano for Real Time Eruptive Cloud Measurements

    NASA Astrophysics Data System (ADS)

    Diaz, J. A.; Pieri, D. C.; Fladeland, M. M.; Bland, G.; Corrales, E.; Alan, A., Jr.; Alegria, O.; Kolyer, R.

    2015-12-01

    The development of small unmanned aerial systems (sUAS) with a variety of instrument packages enables in situ and proximal remote sensing measurements of volcanic plumes, even when the active conditions of the volcano do not allow volcanologists and emergency response personnel to get too close to the erupting crater. This has been demonstrated this year by flying a sUAS through the heavy ash driven erupting volcanic cloud of Turrialba Volcano, while conducting real time in situ measurement of gases over the crater summit. The event also achieved the collection of newly released ash samples from the erupting volcano. The interception of the Turrialba ash cloud occurred during the CARTA 2015 field campaign carried out as part of an ongoing program for remote sensing satellite calibration and validation purposes, using active volcanic plumes. These deployments are timed to support overflights of the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) onboard the NASA Terra satellite on a bimonthly basis using airborne platforms such as tethered balloons, free-flying fixed wing small UAVs at altitudes up to 12.5Kft ASL within about a 5km radius of the summit crater. The onboard instrument includes the MiniGas payload which consists of an array of single electrochemical and infrared gas detectors (SO2, H2S CO2), temperature, pressure, relative humidity and GPS sensors, all connected to an Arduino-based board, with data collected at 1Hz. Data are both stored onboard and sent by telemetry to the ground operator within a 3 km range. The UAV can also carry visible and infrared cameras as well as other payloads, such as a UAV-MS payload that is currently under development for mass spectrometer-based in situ measurements. The presentation describes the ongoing UAV- based in situ remote sensing validation program at Turrialba Volcano, the results of a fly-through the eruptive cloud, as well as future plans to continue these efforts. Work presented here was

  4. New optical sensor systems for high-resolution satellite, airborne and terrestrial imaging systems

    NASA Astrophysics Data System (ADS)

    Eckardt, Andreas; Börner, Anko; Lehmann, Frank

    2007-10-01

    The department of Optical Information Systems (OS) at the Institute of Robotics and Mechatronics of the German Aerospace Center (DLR) has more than 25 years experience with high-resolution imaging technology. The technology changes in the development of detectors, as well as the significant change of the manufacturing accuracy in combination with the engineering research define the next generation of spaceborne sensor systems focusing on Earth observation and remote sensing. The combination of large TDI lines, intelligent synchronization control, fast-readable sensors and new focal-plane concepts open the door to new remote-sensing instruments. This class of instruments is feasible for high-resolution sensor systems regarding geometry and radiometry and their data products like 3D virtual reality. Systemic approaches are essential for such designs of complex sensor systems for dedicated tasks. The system theory of the instrument inside a simulated environment is the beginning of the optimization process for the optical, mechanical and electrical designs. Single modules and the entire system have to be calibrated and verified. Suitable procedures must be defined on component, module and system level for the assembly test and verification process. This kind of development strategy allows the hardware-in-the-loop design. The paper gives an overview about the current activities at DLR in the field of innovative sensor systems for photogrammetric and remote sensing purposes.

  5. Airborne Particles.

    ERIC Educational Resources Information Center

    Ojala, Carl F.; Ojala, Eric J.

    1987-01-01

    Describes an activity in which students collect airborne particles using a common vacuum cleaner. Suggests ways for the students to convert their data into information related to air pollution and human health. Urges consideration of weather patterns when analyzing the results of the investigation. (TW)

  6. Airborne Cloud Computing Environment (ACCE)

    NASA Technical Reports Server (NTRS)

    Hardman, Sean; Freeborn, Dana; Crichton, Dan; Law, Emily; Kay-Im, Liz

    2011-01-01

    Airborne Cloud Computing Environment (ACCE) is JPL's internal investment to improve the return on airborne missions. Improve development performance of the data system. Improve return on the captured science data. The investment is to develop a common science data system capability for airborne instruments that encompasses the end-to-end lifecycle covering planning, provisioning of data system capabilities, and support for scientific analysis in order to improve the quality, cost effectiveness, and capabilities to enable new scientific discovery and research in earth observation.

  7. Role of mechanical ventilation in the airborne transmission of infectious agents in buildings.

    PubMed

    Luongo, J C; Fennelly, K P; Keen, J A; Zhai, Z J; Jones, B W; Miller, S L

    2016-10-01

    Infectious disease outbreaks and epidemics such as those due to SARS, influenza, measles, tuberculosis, and Middle East respiratory syndrome coronavirus have raised concern about the airborne transmission of pathogens in indoor environments. Significant gaps in knowledge still exist regarding the role of mechanical ventilation in airborne pathogen transmission. This review, prepared by a multidisciplinary group of researchers, focuses on summarizing the strengths and limitations of epidemiologic studies that specifically addressed the association of at least one heating, ventilating and/or air-conditioning (HVAC) system-related parameter with airborne disease transmission in buildings. The purpose of this literature review was to assess the quality and quantity of available data and to identify research needs. This review suggests that there is a need for well-designed observational and intervention studies in buildings with better HVAC system characterization and measurements of both airborne exposures and disease outcomes. Studies should also be designed so that they may be used in future quantitative meta-analyses.

  8. The Airborne Cloud-Aerosol Transport System. Part I; Overview and Description of the Instrument and Retrival Algorithms

    NASA Technical Reports Server (NTRS)

    Yorks, John E.; Mcgill, Matthew J.; Scott, V. Stanley; Kupchock, Andrew; Wake, Shane; Hlavka, Dennis; Hart, William; Selmer, Patrick

    2014-01-01

    The Airborne Cloud-Aerosol Transport System (ACATS) is a multi-channel Doppler lidar system recently developed at NASA Goddard Space Flight Center (GSFC). A unique aspect of the multi-channel Doppler lidar concept such as ACATS is that it is also, by its very nature, a high spectral resolution lidar (HSRL). Both the particulate and molecular scattered signal can be directly and unambiguously measured, allowing for direct retrievals of particulate extinction. ACATS is therefore capable of simultaneously resolving the backscatterextinction properties and motion of a particle from a high altitude aircraft. ACATS has flown on the NASA ER-2 during test flights over California in June 2012 and science flights during the Wallops Airborne Vegetation Experiment (WAVE) in September 2012. This paper provides an overview of the ACATS method and instrument design, describes the ACATS retrieval algorithms for cloud and aerosol properties, and demonstrates the data products that will be derived from the ACATS data using initial results from the WAVE project. The HSRL retrieval algorithms developed for ACATS have direct application to future spaceborne missions such as the Cloud-Aerosol Transport System (CATS) to be installed on the International Space Station (ISS). Furthermore, the direct extinction and particle wind velocity retrieved from the ACATS data can be used for science applications such 27 as dust or smoke transport and convective outflow in anvil cirrus clouds.

  9. InSAR and GPS measurements along the Kivu segment of the East African Rift System during the 2011-2012 Nyamulagira volcanic eruption.

    NASA Astrophysics Data System (ADS)

    Nobile, Adriano; Geirsson, Halldor; Smets, Benoît; d'Oreye, Nicolas; Kervyn, François

    2016-04-01

    Along the East African Rift System (EARS), magma intrusions represent a major component in continental rifting. When these intrusions reach the surface, they cause volcanic eruptions. This is the case of the last flank eruption of Nyamulagira, which occurred from November 6 2011 to April 2012. Nyamulagira is an active shield volcano with a central caldera, located in the eastern part of the Democratic Republic of Congo, along the Kivu segment of the East African Rift System. From 1948 to 2012, Nyamulagira mostly showed a particular eruptive cycle with 1) classical short-lived (i.e., 20-30 days) flank eruptions, sometimes accompanied with intracrateral activity, which occurred every 1-4 years on average, and 2) less frequent long-lived (i.e., several months) eruptions usually emitting larger volumes of lava that take place at larger distance (>8 km) from the central caldera. The 2011-2012 Nyamulagira eruption is of that second type. Here we used InSAR data from different satellite (Envisat, Cosmo SkyMed, TerraSAR-X and RADARSAT) to measure pre-, co and post-eruptive ground displacement associated with the Nyamulagira 2011-2012 eruption. Results suggest that a magma intrusion preceded by two days the eruption. This intrusion corresponded to the migration of magma from a shallow reservoir (~3km) below the caldera to the two eruptive fissures located ~11 km ENE of the central edifice. Available seismic data are in agreement with InSAR results showing increased seismic activity since November 4 2011, with long- and short-period earthquakes swarms. Using analytical models we invert the measured ground displacements during the first co-eruptive month to evaluate the deformation source parameters and the mechanism of magma emplacement for this eruption. GPS data from permanent stations in the KivuGNet network are used to constrain the temporal evolution of the eruption and evaluate far-field deformation, while the InSAR data is more sensitive to the near-field deformation

  10. Recognizing Airborne Hazards.

    ERIC Educational Resources Information Center

    Schneider, Christian M.

    1990-01-01

    The heating, ventilating, and air conditioning (HVAC) systems in older buildings often do not adequately handle air-borne contaminants. Outlines a three-stage Indoor Air Quality (IAQ) assessment and describes a case in point at a Pittsburgh, Pennsylvania, school. (MLF)

  11. 23. OVERVIEW OF SAR3 AREA, SHOWING CORNER OF SAR3 WITH ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    23. OVERVIEW OF SAR-3 AREA, SHOWING CORNER OF SAR-3 WITH TAILRACE, ADMINISTRATIVE OFFICE, TOILET SHED, AND RETAINING WALLS AT FORMER EMPLOYEE HOUSING SITE. VIEW TO SOUTHEAST. PANORAMA 1/2. - Santa Ana River Hydroelectric System, Redlands, San Bernardino County, CA

  12. Combined DEM Extration Method from StereoSAR and InSAR

    NASA Astrophysics Data System (ADS)

    Zhao, Z.; Zhang, J. X.; Duan, M. Y.; Huang, G. M.; Yang, S. C.

    2015-06-01

    A pair of SAR images acquired from different positions can be used to generate digital elevation model (DEM). Two techniques exploiting this characteristic have been introduced: stereo SAR and interferometric SAR. They permit to recover the third dimension (topography) and, at the same time, to identify the absolute position (geolocation) of pixels included in the imaged area, thus allowing the generation of DEMs. In this paper, StereoSAR and InSAR combined adjustment model are constructed, and unify DEM extraction from InSAR and StereoSAR into the same coordinate system, and then improve three dimensional positioning accuracy of the target. We assume that there are four images 1, 2, 3 and 4. One pair of SAR images 1,2 meet the required conditions for InSAR technology, while the other pair of SAR images 3,4 can form stereo image pairs. The phase model is based on InSAR rigorous imaging geometric model. The master image 1 and the slave image 2 will be used in InSAR processing, but the slave image 2 is only used in the course of establishment, and the pixels of the slave image 2 are relevant to the corresponding pixels of the master image 1 through image coregistration coefficient, and it calculates the corresponding phase. It doesn't require the slave image in the construction of the phase model. In Range-Doppler (RD) model, the range equation and Doppler equation are a function of target geolocation, while in the phase equation, the phase is also a function of target geolocation. We exploit combined adjustment model to deviation of target geolocation, thus the problem of target solution is changed to solve three unkonwns through seven equations. The model was tested for DEM extraction under spaceborne InSAR and StereoSAR data and compared with InSAR and StereoSAR methods respectively. The results showed that the model delivered a better performance on experimental imagery and can be used for DEM extraction applications.

  13. Synthetic Aperture Radar (SAR)-based paddy rice monitoring system: Development and application in key rice producing areas in Tropical Asia

    NASA Astrophysics Data System (ADS)

    Setiyono, T. D.; Holecz, F.; Khan, N. I.; Barbieri, M.; Quicho, E.; Collivignarelli, F.; Maunahan, A.; Gatti, L.; Romuga, G. C.

    2017-01-01

    Reliable and regular rice information is essential part of many countries’ national accounting process but the existing system may not be sufficient to meet the information demand in the context of food security and policy. Synthetic Aperture Radar (SAR) imagery is highly suitable for detecting lowland paddy rice, especially in tropical region where pervasive cloud cover in the rainy seasons limits the use of optical imagery. This study uses multi-temporal X-band and C-band SAR imagery, automated image processing, rule-based classification and field observations to classify rice in multiple locations across Tropical Asia and assimilate the information into ORYZA Crop Growth Simulation model (CGSM) to generate high resolution yield maps. The resulting cultivated rice area maps had classification accuracies above 85% and yield estimates were within 81-93% agreement against district level reported yields. The study sites capture much of the diversity in water management, crop establishment and rice maturity durations and the study demonstrates the feasibility of rice detection, yield monitoring, and damage assessment in case of climate disaster at national and supra-national scales using multi-temporal SAR imagery combined with CGSM and automated methods.

  14. Low loss, flexible, lightweight corporate RF feed system for SAR antenna application

    NASA Technical Reports Server (NTRS)

    Schiavone, F.

    1978-01-01

    Mechanical and electrical efficiency constraints imposed by the SEASAT-A synthetic aperture radar antenna posed difficult design problems. After consideration of available standard cable and waveguide systems, it was determined that an optimum design could be obtained from a suspended substrate RF feed system. Size and mechanical flexibility constraints forced the design of a flexible, suspended substrate section capable of 180-degree flexure. Original design goal for insertion loss over power division was 1 db; measured results indicated 0.6 db maximum across the band. Multipactor testing of system components indicated system breakdown capability in excess of 4 kW compared to a specification input maximum of 1500 W.

  15. Sensor System Performance Evaluation and Benefits from the NPOESS Airborne Sounder Testbed-Interferometer (NAST-I)

    NASA Technical Reports Server (NTRS)

    Larar, A.; Zhou, D.; Smith, W.

    2009-01-01

    Advanced satellite sensors are tasked with improving global-scale measurements of the Earth's atmosphere, clouds, and surface to enable enhancements in weather prediction, climate monitoring, and environmental change detection. Validation of the entire measurement system is crucial to achieving this goal and thus maximizing research and operational utility of resultant data. Field campaigns employing satellite under-flights with well-calibrated FTS sensors aboard high-altitude aircraft are an essential part of this validation task. The National Polar-orbiting Operational Environmental Satellite System (NPOESS) Airborne Sounder Testbed-Interferometer (NAST-I) has been a fundamental contributor in this area by providing coincident high spectral/spatial resolution observations of infrared spectral radiances along with independently-retrieved geophysical products for comparison with like products from satellite sensors being validated. This paper focuses on some of the challenges associated with validating advanced atmospheric sounders and the benefits obtained from employing airborne interferometers such as the NAST-I. Select results from underflights of the Aqua Atmospheric InfraRed Sounder (AIRS) and the Infrared Atmospheric Sounding Interferometer (IASI) obtained during recent field campaigns will be presented.

  16. Along-strike variations of the partitioning of convergence across the Haiyuan fault system detected by InSAR

    NASA Astrophysics Data System (ADS)

    Daout, S.; Jolivet, R.; Lasserre, C.; Doin, M.-P.; Barbot, S.; Tapponnier, P.; Peltzer, G.; Socquet, A.; Sun, J.

    2016-04-01

    Oblique convergence across Tibet leads to slip partitioning with the coexistence of strike-slip, normal and thrust motion on major fault systems. A key point is to understand and model how faults interact and accumulate strain at depth. Here, we extract ground deformation across the Haiyuan Fault restraining bend, at the northeastern boundary of the Tibetan plateau, from Envisat radar data spanning the 2001-2011 period. We show that the complexity of the surface displacement field can be explained by the partitioning of a uniform deep-seated convergence. Mountains and sand dunes in the study area make the radar data processing challenging and require the latest developments in processing procedures for Synthetic Aperture Radar interferometry. The processing strategy is based on a small baseline approach. Before unwrapping, we correct for atmospheric phase delays from global atmospheric models and digital elevation model errors. A series of filtering steps is applied to improve the signal-to-noise ratio across high ranges of the Tibetan plateau and the phase unwrapping capability across the fault, required for reliable estimate of fault movement. We then jointly invert our InSAR time-series together with published GPS displacements to test a proposed long-term slip-partitioning model between the Haiyuan and Gulang left-lateral Faults and the Qilian Shan thrusts. We explore the geometry of the fault system at depth and associated slip rates using a Bayesian approach and test the consistency of present-day geodetic surface displacements with a long-term tectonic model. We determine a uniform convergence rate of 10 [8.6-11.5] mm yr-1 with an N89 [81-97]°E across the whole fault system, with a variable partitioning west and east of a major extensional fault-jog (the Tianzhu pull-apart basin). Our 2-D model of two profiles perpendicular to the fault system gives a quantitative understanding of how crustal deformation is accommodated by the various branches of this

  17. Temporal Development of Repeated Intrusive Events in a South Iceland Volcanic System, Inferred From InSAR Measurements

    NASA Astrophysics Data System (ADS)

    Pedersen, R.; Sigmundsson, F.

    2002-12-01

    We present measurements of volcano deformation from a series of 18 interferograms spanning the years 1993-2000. The detected deformation originates from repeated intrusions in the Eyjafjallaj”kull system, an icecap covered stratovolcano situated in, what is considered to be, a propagating rift zone in southern Iceland. The volcano erupts infrequently, with only two known eruptions in historic time (last 1100 years). The eruptive products are alkaline in composition, with only small volumes produced in recent eruptions. In spite of the apparent silence of this system two intrusive episodes have been detected within the last decade, causing major concern in the local community. In 1994, and again in 1999, seismic unrest associated with magmatic intrusions occurred in the system. Crustal deformation associated with the events was detected by dry-tilt, GPS and interferometry. During the 1994 episode, the center of deformation was situated underneath the icecap, and the area experiencing maximum uplift was therefore within the zone of decorrelation. The deformation shows an oval fringe pattern, which reaches well beyond the icecap, covering more than 300 km2 in total. Up to 15 cm of LOS ("line of sight") displacement is observed. The temporal resolution of the InSAR images during the 1999 intrusive episode is better and it is possible to follow the development of the intrusive event through time. The center of deformation does not coincide with the center from the 1994 event, but is situated just south of the icecap. The deformation during this event amounts to about 20 cm of LOS. Several of the interferograms cover the whole time-span of the 1999 intrusion, but three interferograms cover different periods of the intrusive event. The data set enables us to follow the temporal development of the crustal deformation created by the intrusion, and hence the growth of the intrusion itself through time. A previous study based on forward modeling of GPS and tilt data

  18. Formal methods and their role in digital systems validation for airborne systems

    NASA Technical Reports Server (NTRS)

    Rushby, John

    1995-01-01

    This report is based on one prepared as a chapter for the FAA Digital Systems Validation Handbook (a guide to assist FAA certification specialists with advanced technology issues). Its purpose is to explain the use of formal methods in the specification and verification of software and hardware requirements, designs, and implementations; to identify the benefits, weaknesses, and difficulties in applying these methods to digital systems used in critical applications; and to suggest factors for consideration when formal methods are offered in support of certification. The presentation concentrates on the rationale for formal methods and on their contribution to assurance for critical applications within a context such as that provided by DO-178B (the guidelines for software used on board civil aircraft); it is intended as an introduction for those to whom these topics are new.

  19. Life-Cycle-Cost Analysis of the Microwave Landing System Ground and Airborne Systems

    DTIC Science & Technology

    1981-10-01

    relative costs and reliability of the system have been programmed into the cost model. 5.3 RESULTS OF APPLYING THE ECONOMIC ANALYSIS MODEL The ARINC ...Young, K. Peter 1326-01-16-2547 9. Porferintg Ogeni etiet Noise and Address 10. WoA Unit No. (TRAIS) ARINC Reseaarch Corporation 2551 Riva Road 11...Throughout this study, ARINC Research Corporation received enthusiastic and invaluable support from the engineering and management staffs of the Federal

  20. Detection of land degradation with polarimetric SAR

    NASA Technical Reports Server (NTRS)

    Ray, Terrill W.; Farr, Tom G.; Van Zyl, Jakob J.

    1992-01-01

    Multispectral radar polarimeter data were collected over the Manix Basin Area of the Mojave desert using an airborne SAR. An analysis of the data reveals unusual polarization responses which are attributed to the formation of wind ripples on the surfaces of fields that have been abandoned for more than 5 years. This hypothesis has been confirmed through field observations, and a second-order perturbation model is shown to effectively model the polarization responses. The results demonstrate the usefulness of remote sensing techniques for the study of land degradation at synoptic scales.

  1. Using InSAR to Evaluate Pumping-Related Aquifer-System Response Between 1992 and 2007 in Ground-Water Basins of Eastern Nevada

    NASA Astrophysics Data System (ADS)

    Donovan, D. J.; Arai, R.; Bell, J.

    2008-12-01

    Interferometric synthetic aperture radar (InSAR) has become a commonly used tool to detect and measure the magnitude and spatial variation of aquifer-system response, specifically subsidence, in groundwater basins in Nevada. Previous work has included InSAR studies of Las Vegas, which has a well-documented history of water-level changes and subsidence. The purpose of this study was to extend InSAR studies from Las Vegas to the north to Ely, Nevada in order to evaluate on a reconnaissance level the present groundwater system response to pumping in 35 hydrographic basins. These data will form a baseline for the proposed Southern Nevada Water Authority's In-state Groundwater Project which is designed to provide as much as 202 hm3/yr (164,000 acre-ft/yr) from 6 of these basins to the Las Vegas metropolitan area. We have processed more than 100 interferometric pairs using ERS and Envisat data from the WInSAR and GeoEarthscope archives covering the time period 1992-2007. Results were analyzed in time series in order to identify potential atmospheric and topographic artifacts, and to verify the occurrence of the groundwater signal. The preliminary results show that some principal groundwater basins currently undergoing moderate levels of groundwater pumping exhibit small, localized subsidence signals of a few centimeters for one or more years. These basins include Lake, Patterson, Butte, and White River Valleys, where annual pumping rates are on the order of 2.5-16.0 hm3/yr (2000-13,000 acre-ft/yr). Spring and Cave Valleys have localized subsidence signals away from known pumping centers. Localized signals are also located near the towns of McGill and Ely, Nevada in Steptoe Valley. These small amplitude signals are consistent with the low to moderate levels of pumping presently occurring in these valleys. The InSAR results also showed that some other basins undergoing moderate levels of pumping do not exhibit any visible evidence of aquifer-system impact. Due to the

  2. TerraSAR-X high-resolution radar remote sensing: an operational warning system for Rift Valley fever risk.

    PubMed

    Vignolles, Cécile; Tourre, Yves M; Mora, Oscar; Imanache, Laurent; Lafaye, Murielle

    2010-11-01

    In the vicinity of the Barkedji village (in the Ferlo region of Senegal), the abundance and aggressiveness of the vector mosquitoes for Rift Valley fever (RVF) are strongly linked to rainfall events and associated ponds dynamics. Initially, these results were obtained from spectral analysis of high-resolution (~10 m) Spot-5 images, but, as a part of the French AdaptFVR project, identification of the free water dynamics within ponds was made with the new high-resolution (down to 3-meter pixels), Synthetic Aperture Radar satellite (TerraSAR-X) produced by Infoterra GmbH, Friedrichshafen/Potsdam, Germany. During summer 2008, within a 30 x 50 km radar image, it was found that identified free water fell well within the footprints of ponds localized by optical data (i.e. Spot-5 images), which increased the confidence in this new and complementary remote sensing technique. Moreover, by using near real-time rainfall data from the Tropical Rainfall Measuring Mission (TRMM), NASA/JAXA joint mission, the filling-up and flushing-out rates of the ponds can be accurately determined. The latter allows for a precise, spatio-temporal mapping of the zones potentially occupied by mosquitoes capable of revealing the variability of pond surfaces. The risk for RVF infection of gathered bovines and small ruminants (~1 park/km(2)) can thus be assessed. This new operational approach (which is independent of weather conditions) is an important development in the mapping of risk components (i.e. hazards plus vulnerability) related to RVF transmission during the summer monsoon, thus contributing to a RVF early warning system.

  3. Airborne Systems Software Acquisition Engineering Guidebook for Requirements Analysis and Specification.

    DTIC Science & Technology

    1978-09-01

    analysis should be included for each C PCI, e.g., the F-X RDPS. If CPCI’s have not been identified, the airborne software qystem can be treated as a...Fre y Destination mFunction Paragraph SR Symbol NA 0 1 (a5 5 Air-to-Air 3.2. 1Reject O Depresion deg 0 360 0.01 5 Air-to-Air 3.2. 1 Angle Table 4-5. F...making logic. The human engineering requirements should pro- vide enough information about the crew performance so that the crew members can be treated

  4. A study on airborne integrated display system and human information processing

    NASA Technical Reports Server (NTRS)

    Mizumoto, K.; Iwamoto, H.; Shimizu, S.; Kuroda, I.

    1983-01-01

    The cognitive behavior of pilots was examined in an experiment involving mock ups of an eight display electronic attitude direction indicator for an airborne integrated display. Displays were presented in digital, analog digital, and analog format to experienced pilots. Two tests were run, one involving the speed of memorization in a single exposure and the other comprising two five second exposures spaced 30 sec apart. Errors increased with the speed of memorization. Generally, the analog information was assimilated faster than the digital data, with regard to the response speed. Information processing was quantified as 25 bits for the first five second exposure and 15 bits during the second.

  5. A Multispectral Image Creating Method for a New Airborne Four-Camera System with Different Bandpass Filters.

    PubMed

    Li, Hanlun; Zhang, Aiwu; Hu, Shaoxing

    2015-07-20

    This paper describes an airborne high resolution four-camera multispectral system which mainly consists of four identical monochrome cameras equipped with four interchangeable bandpass filters. For this multispectral system, an automatic multispectral data composing method was proposed. The homography registration model was chosen, and the scale-invariant feature transform (SIFT) and random sample consensus (RANSAC) were used to generate matching points. For the difficult registration problem between visible band images and near-infrared band images in cases lacking manmade objects, we presented an effective method based on the structural characteristics of the system. Experiments show that our method can acquire high quality multispectral images and the band-to-band alignment error of the composed multiple spectral images is less than 2.5 pixels.

  6. A Multispectral Image Creating Method for a New Airborne Four-Camera System with Different Bandpass Filters

    PubMed Central

    Li, Hanlun; Zhang, Aiwu; Hu, Shaoxing

    2015-01-01

    This paper describes an airborne high resolution four-camera multispectral system which mainly consists of four identical monochrome cameras equipped with four interchangeable bandpass filters. For this multispectral system, an automatic multispectral data composing method was proposed. The homography registration model was chosen, and the scale-invariant feature transform (SIFT) and random sample consensus (RANSAC) were used to generate matching points. For the difficult registration problem between visible band images and near-infrared band images in cases lacking manmade objects, we presented an effective method based on the structural characteristics of the system. Experiments show that our method can acquire high quality multispectral images and the band-to-band alignment error of the composed multiple spectral images is less than 2.5 pixels. PMID:26205264

  7. A system to geometrically rectify and map airborne scanner imagery and to estimate ground area. [by computer

    NASA Technical Reports Server (NTRS)

    Spencer, M. M.; Wolf, J. M.; Schall, M. A.

    1974-01-01

    A system of computer programs were developed which performs geometric rectification and line-by-line mapping of airborne multispectral scanner data to ground coordinates and estimates ground area. The system requires aircraft attitude and positional information furnished by ancillary aircraft equipment, as well as ground control points. The geometric correction and mapping procedure locates the scan lines, or the pixels on each line, in terms of map grid coordinates. The area estimation procedure gives ground area for each pixel or for a predesignated parcel specified in map grid coordinates. The results of exercising the system with simulated data showed the uncorrected video and corrected imagery and produced area estimates accurate to better than 99.7%.

  8. Primary studies of Chinese spaceborne SAR

    NASA Technical Reports Server (NTRS)

    Wang, Zhen-Song; Wu, Guo-Xiang; Guo, Hua-Dong; Wei, Zhong-Quan; Zhu, Min-Hui

    1993-01-01

    The primary studies on spaceborne synthetic aperture radar (SAR) in China are discussed. The SAR will be launched aboard a Chinese satellite and operated at L-band with HH polarization. The purpose of the mission in consideration is dedicated to resources and environment uses, especially to natural disaster monitoring. The ground resolution is designed as 25 m x 25 m for detailed mode and 100 m x 100 m for wide scan-SAR mode. The off-nadir angle can be varied from 20 to 40 deg. The key system concepts are introduced.

  9. NASA/JPL Aircraft SAR Workshop Proceedings

    NASA Technical Reports Server (NTRS)

    Donovan, N. (Editor); Evans, D. L. (Editor); Held, D. N. (Editor)

    1985-01-01

    Speaker-supplied summaries of the talks given at the NASA/JPL Aircraft SAR Workshop on February 4 and 5, 1985, are provided. These talks dealt mostly with composite quadpolarization imagery from a geologic or ecologic prespective. An overview and summary of the system characteristics of the L-band synthetic aperture radar (SAR) flown on the NASA CV-990 aircraft are included as supplementary information. Other topics ranging from phase imagery and interferometric techniques classifications of specific areas, and the potentials and limitations of SAR imagery in various applications are discussed.

  10. Airborne ultraviolet imaging system for oil slick surveillance: oil-seawater contrast, imaging concept, signal-to-noise ratio, optical design, and optomechanical model.

    PubMed

    Shi, Zhenhua; Yu, Lei; Cao, Diansheng; Wu, Qingwen; Yu, Xiangyang; Lin, Guanyu

    2015-09-01

    The airborne ultraviolet imaging system, which assesses oil slick areas better than visible and infrared optical systems, was designed to monitor and track oil slicks in coastal regions. A model was built to achieve the upwelling radiance distribution of oil-covered sea and clean seawater, based on the radiance transfer software. With this model, the oil-seawater contrast, which affects the detection of oil-covered coastal areas, was obtained. The oil-seawater contrast, fundamental imaging concept, analog calculation of SNR, optical design, and optomechanical configuration of the airborne ultraviolet imaging system are illustrated in this paper. The study of an airborne ultraviolet imaging system with F-number 3.4 and a 40° field of view (FOV) in near ultraviolet channel (0.32-0.38 μm) was illustrated and better imaging quality was achieved. The ground sample distance (GSD) is from 0.35 to 0.7 m with flight height ranges from 0.5 to 1 km. Comparisons of detailed characteristics of the airborne ultraviolet imaging system with the corresponding characteristics of previous ultraviolet systems were tabulated, and these comparisons showed that this system can achieve a wide FOV and a relative high SNR. A virtual mechanical prototype and tolerances analysis are illustrated in this paper to verify the performance of fabrication and assembly of the ultraviolet system.

  11. High Resolution Digital Surface Model For Production Of Airport Obstruction Charts Using Spaceborne SAR Sensors

    NASA Astrophysics Data System (ADS)

    Oliveira, Henrique; Rodrigues, Marco; Radius, Andrea

    2012-01-01

    Airport Obstruction Charts (AOCs) are graphical representations of natural or man-made obstructions (its locations and heights) around airfields, according to International Civil Aviation Organization (ICAO) Annexes 4, 14 and 15. One of the most important types of data used in AOCs production/update tasks is a Digital Surface Model (first reflective surface) of the surveyed area. The development of advanced remote sensing technologies provide the available tools for obstruction data acquisition, while Geographic Information Systems (GIS) present the perfect platform for storing and analyzing this type of data, enabling the production of digital ACOs, greatly contributing to the increase of the situational awareness of pilots and enhancing the air navigation safety level [1]. Data acquisition corresponding to the first reflective surface can be obtained through the use of Airborne Laser-Scanning and Light Detection and Ranging (ALS/LIDAR) or Spaceborne SAR Systems. The need of surveying broad areas, like the entire territory of a state, shows that Spaceborne SAR systems are the most adequate in economic and feasibility terms of the process, to perform the monitoring and producing a high resolution Digital Surface Model (DSM). The high resolution DSM generation depends on many factors: the available data set, the used technique and the setting parameters. To increase the precision and obtain high resolution products, two techniques are available using a stack of data: the PS (Permanent Scatterers) technique [2], that uses large stack of data to identify many stable and coherent targets through multi- temporal analysis, removing the atmospheric contribution and to minimize the estimation errors, and the Small Baseline Subset (SBAS) technique ([3],[4]), that relies on the use of small baseline SAR interferograms and on the application of the so called singular value decomposition (SVD) method, in order to link independent SAR acquisition data sets, separated by large

  12. SAR in support of geological investigations of the Sudbury structure

    NASA Technical Reports Server (NTRS)

    Singhroy, V.; Mussakowski, R.; Dressler, B. O.; Trowell, N. F.; Grieve, Richard

    1992-01-01

    Imaging radar is an important contributing source of information for a range of geological problems and environments. Airborne SAR and ERS-1 data integrated with other geoscience datasets are being used in an attempt to characterize the crustal fracturing associated with the Sudbury structure. This presentation highlights examples of integrated and composite images aimed at facilitating the interpretation of the Sudbury structure. This work is the result of an ongoing cooperative multidisciplinary SAR study of the basin carried out by the Canada Center for Remote Sensing, Ontario's provincial Remote Sensing Office, the Ontario Geological Survey, and the Geological Survey of Canada.

  13. Determination of airborne cadmium in environmental tobacco smoke by instrumental neutron activation analysis with a compton suppression system.

    PubMed

    Landsberger, S; Larson, S; Wu, D

    1993-06-01

    Concentrations of cadmium, a toxic trace element, were measured in the indoor air of several public places where environmental tobacco smoke was present. Particulate-phase cadmium concentrations were determined by analyzing air filter samples using epithermal instrumental neutron activation analysis in conjunction with a Compton suppression gamma-ray detection system, in which the detection limit for cadmium was reduced to a few nanograms per filter. A cascade impactor and a personal filter sampler were used to collect the indoor suspended particulate matter for size-fractionated mass as well as total mass, respectively. Results show that where environmental tobacco smoke is present, cadmium concentrations are significantly higher than background and that about 80% of the cadmium found in indoor airborne particulate matter is associated with particles with aerodynamic diameters less than 1.8 microns. In one instance, airborne cadmium concentrations in a music club were found to be 38 ng/m, which is at least 30 times higher than background.

  14. SAR and LIDAR fusion: experiments and applications

    NASA Astrophysics Data System (ADS)

    Edwards, Matthew C.; Zaugg, Evan C.; Bradley, Joshua P.; Bowden, Ryan D.

    2013-05-01

    In recent years ARTEMIS, Inc. has developed a series of compact, versatile Synthetic Aperture Radar (SAR) systems which have been operated on a variety of small manned and unmanned aircraft. The multi-frequency-band SlimSAR has demonstrated a variety of capabilities including maritime and littoral target detection, ground moving target indication, polarimetry, interferometry, change detection, and foliage penetration. ARTEMIS also continues to build upon the radar's capabilities through fusion with other sensors, such as electro-optical and infrared camera gimbals and light detection and ranging (LIDAR) devices. In this paper we focus on experiments and applications employing SAR and LIDAR fusion. LIDAR is similar to radar in that it transmits a signal which, after being reflected or scattered by a target area, is recorded by the sensor. The differences are that a LIDAR uses a laser as a transmitter and optical sensors as a receiver, and the wavelengths used exhibit a very different scattering phenomenology than the microwaves used in radar, making SAR and LIDAR good complementary technologies. LIDAR is used in many applications including agriculture, archeology, geo-science, and surveying. Some typical data products include digital elevation maps of a target area and features and shapes extracted from the data. A set of experiments conducted to demonstrate the fusion of SAR and LIDAR data include a LIDAR DEM used in accurately processing the SAR data of a high relief area (mountainous, urban). Also, feature extraction is used in improving geolocation accuracy of the SAR and LIDAR data.

  15. Atmospheric composition and thermodynamic retrievals from the ARIES airborne FTS system - Part 1: Technical aspects and simulated capability

    NASA Astrophysics Data System (ADS)

    Illingworth, S. M.; Allen, G.; Newman, S.; Vance, A.; Marenco, F.; Harlow, R. C.; Taylor, J.; Moore, D. P.; Remedios, J. J.

    2013-12-01

    In this study we present an assessment of the retrieval capability of the Airborne Research Interferometer Evaluation System (ARIES); an airborne remote sensing Fourier Transform Spectrometer (FTS) operated on the UK Facility for Airborne Atmospheric Measurement (FAAM) aircraft. Simulated optimally-estimated-retrievals of partial column trace gas concentrations, and thermodynamic vertical profiles throughout the troposphere and planetary boundary layer have been performed here for simulated infrared spectra representative of the ARIES system. We also describe the operational and technical aspects of the pre-processing necessary for routine retrieval from the FAAM platform and the selection and construction of a priori information. As exemplars of the capability of the ARIES retrieval system, simulated retrievals of temperature, water vapour (H2O), carbon monoxide (CO), ozone (O3), and methane (CH4), and their corresponding sources of error and potential vertical sensitivity, are discussed for ARIES scenes across typical global environments. The maximum Degrees of Freedom for Signal (DOFS) for the retrievals, assuming a flight altitude of 7 km, were: 3.99, 2.97, 0.85, 0.96, and 1.45 for temperature, H2O, CO, O3, and CH4, respectively for the a priori constraints specified. Retrievals of temperature display significant vertical sensitivity (DOFS in the range 2.6 to 4.0 across the altitude range) as well as excellent simulated accuracy, with the vertical sensitivity for H2O also extending to lower altitudes (DOFS ranging from 1.6 to 3.0). It was found that the maximum sensitivity for CO, O3, and CH4 was approximately 1-2 km below the simulated altitudes in all scenarios. Comparisons of retrieved and simulated-truth partial atmospheric columns are used to assess the capability of the ARIES measurement system. Maximum mean biases (and bias standard deviations) in partial columns (i.e. below aircraft total columns) were found to be: +0.06 (±0.02 at 1σ) %, +3.95 (±3

  16. Atmospheric composition and thermodynamic retrievals from the ARIES airborne FTS system - Part 1: Technical aspects and simulated capability

    NASA Astrophysics Data System (ADS)

    Illingworth, S. M.; Allen, G.; Newman, S.; Vance, A.; Marenco, F.; Harlow, R. C.; Taylor, J.; Moore, D. P.; Remedios, J. J.

    2014-04-01

    In this study we present an assessment of the retrieval capability of the Airborne Research Interferometer Evaluation System (ARIES): an airborne remote-sensing Fourier transform spectrometer (FTS) operated on the UK Facility for Airborne Atmospheric Measurement (FAAM) aircraft. Simulated maximum a posteriori retrievals of partial column trace gas concentrations, and thermodynamic vertical profiles throughout the troposphere and planetary boundary layer have been performed here for simulated infrared spectra representative of the ARIES system operating in the nadir-viewing geometry. We also describe the operational and technical aspects of the pre-processing necessary for routine retrieval from the FAAM platform and the selection and construction of a priori information. As exemplars of the capability of the ARIES retrieval system, simulated retrievals of temperature, water vapour (H2O), carbon monoxide (CO), ozone (O3), and methane (CH4), and their corresponding sources of error and potential vertical sensitivity, are discussed for ARIES scenes across typical global environments. The maximum Degrees of Freedom for Signal (DOFS) for the retrievals, assuming a flight altitude of 7 km, were 3.99, 2.97, 0.85, 0.96, and 1.45 for temperature, H2O, CO, O3, and CH4, respectively, for the a priori constraints specified. Retrievals of temperature display significant vertical sensitivity (DOFS in the range 2.6 to 4.0 across the altitude range) as well as excellent simulated accuracy, with the vertical sensitivity for H2O also extending to lower altitudes (DOFS ranging from 1.6 to 3.0). It was found that the maximum sensitivity for CO, O3, and CH4 was approximately 1-2 km below the simulated altitudes in all scenarios. Comparisons of retrieved and simulated-truth partial atmospheric columns are used to assess the capability of the ARIES measurement system. Maximum mean biases (and bias standard deviations) in partial columns (i.e. below aircraft total columns) were found to

  17. A Camera-Based Target Detection and Positioning UAV System for Search and Rescue (SAR) Purposes.

    PubMed

    Sun, Jingxuan; Li, Boyang; Jiang, Yifan; Wen, Chih-Yung

    2016-10-25

    Wilderness search and rescue entails performing a wide-range of work in complex environments and large regions. Given the concerns inherent in large regions due to limited rescue distribution, unmanned aerial vehicle (UAV)-based frameworks are a promising platform for providing aerial imaging. In recent years, technological advances in areas such as micro-technology, sensors and navigation have influenced the various applications of UAVs. In this study, an all-in-one camera-based target detection and positioning system is developed and integrated into a fully autonomous fixed-wing UAV. The system presented in this paper is capable of on-board, real-time target identification, post-target identification and location and aerial image collection for further mapping applications. Its performance is examined using several simulated search and rescue missions, and the test results demonstrate its reliability and efficiency.

  18. A Camera-Based Target Detection and Positioning UAV System for Search and Rescue (SAR) Purposes

    PubMed Central

    Sun, Jingxuan; Li, Boyang; Jiang, Yifan; Wen, Chih-yung

    2016-01-01

    Wilderness search and rescue entails performing a wide-range of work in complex environments and large regions. Given the concerns inherent in large regions due to limited rescue distribution, unmanned aerial vehicle (UAV)-based frameworks are a promising platform for providing aerial imaging. In recent years, technological advances in areas such as micro-technology, sensors and navigation have influenced the various applications of UAVs. In this study, an all-in-one camera-based target detection and positioning system is developed and integrated into a fully autonomous fixed-wing UAV. The system presented in this paper is capable of on-board, real-time target identification, post-target identification and location and aerial image collection for further mapping applications. Its performance is examined using several simulated search and rescue missions, and the test results demonstrate its reliability and efficiency. PMID:27792156

  19. Concept for an airborne real-time ISR system with multi-sensor 3D data acquisition

    NASA Astrophysics Data System (ADS)

    Haraké, Laura; Schilling, Hendrik; Blohm, Christian; Hillemann, Markus; Lenz, Andreas; Becker, Merlin; Keskin, Göksu; Middelmann, Wolfgang

    2016-10-01

    In modern aerial Intelligence, Surveillance and Reconnaissance operations, precise 3D information becomes inevitable for increased situation awareness. In particular, object geometries represented by texturized digital surface models constitute an alternative to a pure evaluation of radiometric measurements. Besides the 3D data's level of detail aspect, its availability is time-relevant in order to make quick decisions. Expanding the concept of our preceding remote sensing platform developed together with OHB System AG and Geosystems GmbH, in this paper we present an airborne multi-sensor system based on a motor glider equipped with two wing pods; one carries the sensors, whereas the second pod downlinks sensor data to a connected ground control station by using the Aerial Reconnaissance Data System of OHB. An uplink is created to receive remote commands from the manned mobile ground control station, which on its part processes and evaluates incoming sensor data. The system allows the integration of efficient image processing and machine learning algorithms. In this work, we introduce a near real-time approach for the acquisition of a texturized 3D data model with the help of an airborne laser scanner and four high-resolution multi-spectral (RGB, near-infrared) cameras. Image sequences from nadir and off-nadir cameras permit to generate dense point clouds and to texturize also facades of buildings. The ground control station distributes processed 3D data over a linked geoinformation system with web capabilities to off-site decision-makers. As the accurate acquisition of sensor data requires boresight calibrated sensors, we additionally examine the first steps of a camera calibration workflow.

  20. Design of a 12-bit 2 MS/s 12 mW pipelined SAR ADC in CMOS 0.18 μm technology for CZT-based imaging system

    NASA Astrophysics Data System (ADS)

    Xue, F.; Gao, W.; Wei, X.; Liu, W.; Hu, Y.

    2016-12-01

    This paper presents a 12-bit 2 MS/s pipelined successive approximation register (SAR) ADC for CZT-based imaging system. The proposed ADC is divided into a first-stage 6-bit SAR-based Multiplying Digital Analog Converter (MDAC) and a second-stage 8-bit SAR ADC. The first-stage MDAC has a gain of 16 instead of the usual gain of 64, which considerably minimizes the power dissipation of residue amplifier. The second-stage 8-bit SAR ADC employs unit bridge capacitor split-capacitor architecture aiming to reduce the load capacitance of residue amplifier so as to minimize the power dissipation of the proposed ADC. Moreover, a code-randomized calibration algorithm is proposed to improve the linearity of the second-stage 8-bit split-capacitor SAR ADC. In addition, several radiation-hardened-by-design techniques are adopted in the layout design against space radiation effects. The prototype chip was fabricated in 0.18 μ m mixed-signal 1.8 V/3.3 V process and occupied a core area of 0.71 mm2. The proposed pipelined SAR ADC achieves a peak signal-to-noise-and-distortion ratio (SNDR) of 63.2 dB at 2 MS/s sampling rate and consumes 12 mW power in total. The figure of merit (FoM) of the proposed ADC is 5.06 pJ/conversion-step.

  1. SAR Interferometry with TerraSAR-X

    NASA Astrophysics Data System (ADS)

    Eineder, M.; Runge, H.; Boerner, E.; Bamler, R.; Adam, N.; Schättler, B.; Breit, H.; Suchandt, S.

    2004-06-01

    The TerraSAR-X project is a public private partnership between Astrium GmbH and the German Aerospace Center DLR. Astrium will launch the satellite in late 2005 and holds the rights of commercial data exploitation. DLR is currently developing the ground segment and is responsible for the scientific exploitation of the data. Even if the mission goal is not primarily SAR interferometry, TerraSAR-X offers a number of new perspectives to SAR interferometry when compared to ERS and also ENVISAT: a) High resolution of 3 meters and better in stripmap and spotlight mode. b) The option for a burst synchronized ScanSAR mode. c) The high range bandwidth will allow large baselines and the option for highly precise DEM generation. d) X- Band will show new scattering properties. e) High observation frequency due to the short repeat cycle and variable incidence angles. f) An along track interferometric mode. The available products relevant for interferometry are presented and other relevant topics like orbit control and delta-k interferometry are discussed.

  2. An analysis of the materiel fielding plan for the SINCGARS (Single Channel Ground and Airborne Radio System) radio

    NASA Astrophysics Data System (ADS)

    Tegen, C. M.

    1984-12-01

    This thesis is an analysis of the materiel fielding plan (MFP) for the Army's Single Channel Ground and Airborne Radio System (SINCGARS). Objectives of the study are to identify major potential problem areas in the MFP, and to generate recommendations for resolving these problems. The study involves a specific analysis of the maintenance and supply support aspects of the MFP within the context of the Major System acquisition framework. Research included extensive field interviews with personnel in the functional management areas of the Communications and Electronics Command (CECOM), the Project Office, and the Department of Army Staff. Potential problems identified concern the redistribution of VRC-12 series and PRC-77 radios, the imbedded COMSEC modification, and the issue of warranties. Recommendations include purchasing a warranty for the original production contract, improving the planning for redistribution of old radios, and providing strict control over the design of the imbedded COMSEC modification.

  3. Enhanced SAR Data Compressor for Sentinel-1

    NASA Astrophysics Data System (ADS)

    Algra, T.; Bierens, L.

    2007-08-01

    This paper presents a new on-board SAR data compressor which outperforms the conventionally used Block Adaptive Quantization (BAQ) compressor. The system applies improved entropy-constrained block adaptive quantization of raw Synthetic Aperture Radar (SAR) data in the frequency domain. For advanced multi-mode satellite SAR instruments, such as the one to be implemented on-board of Sentinel- , the average compression ratio can be doubled as compared to BAQ. Space borne implementation with a high-speed data throughput is feasible due to the advent of advanced space FPGA's and ASIC's including the powerFFT, a fast FFT-oriented DSP. The complete compressor module can be implemented on a 6U Eurocard that fits in the SAR Electronics System crate of Sentinel-1.

  4. InSAR Scientific Computing Environment

    NASA Technical Reports Server (NTRS)

    Rosen, Paul A.; Sacco, Gian Franco; Gurrola, Eric M.; Zabker, Howard A.

    2011-01-01

    This computing environment is the next generation of geodetic image processing technology for repeat-pass Interferometric Synthetic Aperture (InSAR) sensors, identified by the community as a needed capability to provide flexibility and extensibility in reducing measurements from radar satellites and aircraft to new geophysical products. This software allows users of interferometric radar data the flexibility to process from Level 0 to Level 4 products using a variety of algorithms and for a range of available sensors. There are many radar satellites in orbit today delivering to the science community data of unprecedented quantity and quality, making possible large-scale studies in climate research, natural hazards, and the Earth's ecosystem. The proposed DESDynI mission, now under consideration by NASA for launch later in this decade, would provide time series and multiimage measurements that permit 4D models of Earth surface processes so that, for example, climate-induced changes over time would become apparent and quantifiable. This advanced data processing technology, applied to a global data set such as from the proposed DESDynI mission, enables a new class of analyses at time and spatial scales unavailable using current approaches. This software implements an accurate, extensible, and modular processing system designed to realize the full potential of InSAR data from future missions such as the proposed DESDynI, existing radar satellite data, as well as data from the NASA UAVSAR (Uninhabited Aerial Vehicle Synthetic Aperture Radar), and other airborne platforms. The processing approach has been re-thought in order to enable multi-scene analysis by adding new algorithms and data interfaces, to permit user-reconfigurable operation and extensibility, and to capitalize on codes already developed by NASA and the science community. The framework incorporates modern programming methods based on recent research, including object-oriented scripts controlling legacy and

  5. Classification and Monitoring of Salt Marsh Habitats with Multi-Polarimetric and Multi-Frequency SAR

    NASA Astrophysics Data System (ADS)

    van Beijma, Sybrand; Comber, Alexis; Lamb, Alistair; Brown, Sarah

    2013-08-01

    Within GMES there is much interest in the ability of remote sensing technology to deliver operational solutions to many areas of life including environmental management. This paper describes research focused on the application for Earth Observation for Integrated Coastal Zone Management. The main topic of this research is to explore to which extent salt marsh habitats from can be identified from SAR remotely sensed data. Multi-frequency, multi-polarimetric SAR images from airborne (S- and X-Band quad-polarimetric from the Astrium airborne SAR Demonstrator) is used to examine salt marsh habitat classification potential in the Llanrhidian salt marshes in South Wales, UK. This is achieved by characterizing their botanical and structural composition, flooding regimes as well as fluctuations in soil moisture. Different SAR features as backscatter coefficient, band ratios and polarimetric decomposition are extracted.

  6. Use of a Prototype Airborne Separation Assurance System for Resolving Near-Term Conflicts During Autonomous Aircraft Operations

    NASA Technical Reports Server (NTRS)

    Barhydt, Richard; Eischeid, Todd M.; Palmer, Michael T.; Wing, David J.

    2003-01-01

    NASA is currently investigating a new concept of operations for the National Airspace System, designed to improve capacity while maintaining or improving current levels of safety. This concept, known as Distributed Air/Ground Traffic Management (DAGTM), allows appropriately equipped autonomous aircraft to maneuver freely for flight optimization while resolving conflicts with other traffic and staying out of special use airspace and hazardous weather. In order to perform these tasks, pilots use prototype conflict detection, prevention, and resolution tools, collectively known as an Airborne Separation Assurance System (ASAS). While ASAS would normally allow pilots to resolve conflicts before they become hazardous, evaluation of system performance in sudden, near-term conflicts is needed in order to determine concept feasibility. An experiment was conducted in NASA Langley's Air Traffic Operations Lab to evaluate the prototype ASAS for enabling pilots to resolve near-term conflicts and examine possible operational effects associated with the use of lower separation minimums. Sixteen commercial airline pilots flew a total of 32 traffic scenarios that required them to use prototype ASAS tools to resolve close range pop-up conflicts. Required separation standards were set at either 3 or 5 NM lateral spacing, with 1000 ft vertical separation being used for both cases. Reducing the lateral separation from 5 to 3 NM did not appear to increase operational risk, as indicated by the proximity to the intruder aircraft. Pilots performed better when they followed tactical guidance cues provided by ASAS than when they didn't follow the guidance. In an effort to improve compliance rate, ASAS design changes are currently under consideration. Further studies will of evaluate these design changes and consider integration issues between ASAS and existing Airborne Collision Avoidance Systems (ACAS).

  7. Laboratory diagnosis of SARS.

    PubMed Central

    Bermingham, A; Heinen, P; Iturriza-Gómara, M; Gray, J; Appleton, H; Zambon, M C

    2004-01-01

    The emergence of new viral infections of man requires the development of robust diagnostic tests that can be applied in the differential diagnosis of acute illness, or to determine past exposure, so as to establish the true burden of disease. Since the recognition in April 2003 of the severe acute respiratory syndrome coronavirus (SARS-CoV) as the causative agent of severe acute respiratory syndrome (SARS), enormous efforts have been applied to develop molecular and serological tests for SARS which can assist rapid detection of cases, accurate diagnosis of illness and the application of control measures. International progress in the laboratory diagnosis of SARS-CoV infection during acute illness has led to internationally agreed World Health Organization criteria for the confirmation of SARS. Developments in the dissection of the human immune response to SARS indicate that serological tests on convalescent sera are essential to confirm SARS infection, given the sub-optimal predictive value of molecular detection tests performed during acute SARS illness. PMID:15306394

  8. Localized Optimization and Effectiveness Analysis of Medium PRF Airborne Pulse Doppler Radars in the Turkish Air Force

    DTIC Science & Technology

    2011-09-01

    Institute of Electrical and Electronics Engineers ISAR Inverse Synthetic Aperture Radar ITU International Telecommunications Union LOS Line of...Side-Looking Airborne Radar (SLAR) • Synthetic Aperture Radar (SAR) • Inverse Synthetic Aperture Radar ( ISAR ) • Weapon control radar 18...can be detected and tracked. Synthetic Aperture Radar (SAR) and Inverse Synthetic Aperture Radar ( ISAR ) pulse Doppler designs are capable of

  9. Evolving subglacial water systems in East Antarctica from airborne radar sounding

    NASA Astrophysics Data System (ADS)

    Carter, Sasha Peter

    The cold, lightless, and high pressure aquatic environment at the base of the East Antarctic Ice Sheet is of interest to a wide range of disciplines. Stable subglacial lakes and their connecting channels remain perennially liquid three kilometers below some of the coldest places on Earth. The presence of subglacial water impacts flow of the overlying ice and provides clues to the geologic properties of the bedrock below, and may harbor unique life forms which have evolved out of contact with the atmosphere for millions of years. Periodic release of water from this system may impact ocean circulation at the margins of the ice sheet. This research uses airborne radar sounding, with its unique ability to infer properties within and at the base of the ice sheet over large spatial scales, to locate and characterize this unique environment. Subglacial lakes, the primary storage mechanism for subglacial water, have been located and classified into four categories on the basis of the radar reflection properties from the sub-ice interface: Definite lakes are brighter than their surroundings by at least two decibels (relatively bright), and are both consistently reflective (specular) and have a reflection coefficient greater than -10 decibels (absolutely bright). Dim lakes are relatively bright and specular but not absolutely bright, possibly indicating non-steady dynamics in the overlying ice. Fuzzy lakes are both relatively and absolutely bright, but not specular, and may indicate saturated sediments or high frequency spatially heterogeneous distributions of sediment and liquid water (i.e. a braided steam). Indistinct lakes are absolutely bright and specular but no brighter than their surroundings. Lakes themselves and the different classes of lakes are not arranged randomly throughout Antarctica but are clustered around ice divides, ice stream onsets and prominent bedrock troughs, with each cluster demonstrating a different characteristic lake classification distribution

  10. 1. RUINED PORTION OF SANTA ANA CANAL INTAKE ALONGSIDE SAR3 ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    1. RUINED PORTION OF SANTA ANA CANAL INTAKE ALONGSIDE SAR-3 SYSTEM TUNNEL, JUST TO SOUTH OF SAR-2. VIEW TO SOUTHEAST. - Santa Ana River Hydroelectric System, Abandoned Tunnel, Redlands, San Bernardino County, CA

  11. Investigation of ionospheric effects on SAR Interferometry (InSAR): A case study of Hong Kong

    NASA Astrophysics Data System (ADS)

    Zhu, Wu; Ding, Xiao-Li; Jung, Hyung-Sup; Zhang, Qin; Zhang, Bo-Chen; Qu, Wei

    2016-08-01

    Synthetic Aperture Radar Interferometry (InSAR) has demonstrated its potential for high-density spatial mapping of ground displacement associated with earthquakes, volcanoes, and other geologic processes. However, this technique may be affected by the ionosphere, which can result in the distortions of Synthetic Aperture Radar (SAR) images, phases, and polarization. Moreover, ionospheric effect has become and is becoming further significant with the increasing interest in low-frequency SAR systems, limiting the further development of InSAR technique. Although some research has been carried out, thorough analysis of ionospheric influence on true SAR imagery is still limited. Based on this background, this study performs a thorough investigation of ionospheric effect on InSAR through processing L-band ALOS-1/PALSAR-1 images and dual-frequency Global Positioning System (GPS) data over Hong Kong, where the phenomenon of ionospheric irregularities often occurs. The result shows that the small-scale ionospheric irregularities can cause the azimuth pixel shifts and phase advance errors on interferograms. Meanwhile, it is found that these two effects result in the stripe-shaped features in InSAR images. The direction of the stripe-shaped effects keep approximately constant in space for our InSAR dataset. Moreover, the GPS-derived rate of total electron content change index (ROTI), an index to reflect the level of ionospheric disturbances, may be a useful indicator for predicting the ionospheric effect for SAR images. This finding can help us evaluate the quality of SAR images when considering the ionospheric effect.

  12. An Integrated Analysis of Seismic and InSAR data from the June 2012 Koa'e Fault System Earthquake Sequence, Hawai'i

    NASA Astrophysics Data System (ADS)

    Ge, S.; Lin, G.; Amelung, F.; Okubo, P.; Poland, M. P.

    2014-12-01

    The Koa'e fault system is a prominent but poorly understood structural element of Kilauea Volcano, Hawai'i. The ~E-W-trending normal faults that make up the Koa'e system are located about 5 km south of the summit caldera and extend between the East and Southwest Rift Zones, providing a means of accommodating both magma transport between the rifts and extension due to seaward motion of the volcano's south flank. On 5 June 2012, a sequence of shallow earthquakes with magnitudes up to M3.6 occurred within the central part of the Koa'e fault system. InSAR data from multiple satellites spanning the time of the earthquakes indicates a maximum of about 10 cm of down-to-the-north displacement on a known Koa'e fault. Field visits to the fault after the earthquakes found abundant ground cracking. Here, we combine the InSAR data acquired by the COSMO-SkyMed, TSX and RSAT2 systems and seismic data recorded by the Hawaiian Volcanology Observatory to analyze the characteristics of fault rupture. High-precision earthquake locations of the 2012 sequence together with the background seismicity that extends back to 1986 are obtained by applying three-dimensional ray-tracing, similar-event cluster analysis, and waveform cross-correlation methods. The integrated analysis is helpful to better constrain the geometry of the fault, its depth extent, and its role in the structural evolution of Kilauea.

  13. Absolute airborne gravimetry

    NASA Astrophysics Data System (ADS)

    Baumann, Henri

    This work consists of a feasibility study of a first stage prototype airborne absolute gravimeter system. In contrast to relative systems, which are using spring gravimeters, the measurements acquired by absolute systems are uncorrelated and the instrument is not suffering from problems like instrumental drift, frequency response of the spring and possible variation of the calibration factor. The major problem we had to resolve were to reduce the influence of the non-gravitational accelerations included in the measurements. We studied two different approaches to resolve it: direct mechanical filtering, and post-processing digital compensation. The first part of the work describes in detail the different mechanical passive filters of vibrations, which were studied and tested in the laboratory and later in a small truck in movement. For these tests as well as for the airborne measurements an absolute gravimeter FG5-L from Micro-G Ltd was used together with an Inertial navigation system Litton-200, a vertical accelerometer EpiSensor, and GPS receivers for positioning. These tests showed that only the use of an optical table gives acceptable results. However, it is unable to compensate for the effects of the accelerations of the drag free chamber. The second part describes the strategy of the data processing. It is based on modeling the perturbing accelerations by means of GPS, EpiSensor and INS data. In the third part the airborne experiment is described in detail, from the mounting in the aircraft and data processing to the different problems encountered during the evaluation of the quality and accuracy of the results. In the part of data processing the different steps conducted from the raw apparent gravity data and the trajectories to the estimation of the true gravity are explained. A comparison between the estimated airborne data and those obtained by ground upward continuation at flight altitude allows to state that airborne absolute gravimetry is feasible and

  14. Ionospheric Specifications for SAR Interferometry (ISSI)

    NASA Technical Reports Server (NTRS)

    Pi, Xiaoqing; Chapman, Bruce D; Freeman, Anthony; Szeliga, Walter; Buckley, Sean M.; Rosen, Paul A.; Lavalle, Marco

    2013-01-01

    The ISSI software package is designed to image the ionosphere from space by calibrating and processing polarimetric synthetic aperture radar (PolSAR) data collected from low Earth orbit satellites. Signals transmitted and received by a PolSAR are subject to the Faraday rotation effect as they traverse the magnetized ionosphere. The ISSI algorithms combine the horizontally and vertically polarized (with respect to the radar system) SAR signals to estimate Faraday rotation and ionospheric total electron content (TEC) with spatial resolutions of sub-kilometers to kilometers, and to derive radar system calibration parameters. The ISSI software package has been designed and developed to integrate the algorithms, process PolSAR data, and image as well as visualize the ionospheric measurements. A number of tests have been conducted using ISSI with PolSAR data collected from various latitude regions using the phase array-type L-band synthetic aperture radar (PALSAR) onboard Japan Aerospace Exploration Agency's Advanced Land Observing Satellite mission, and also with Global Positioning System data. These tests have demonstrated and validated SAR-derived ionospheric images and data correction algorithms.

  15. Development and testing of an automated High-resolution InSAR volcano-monitoring system in the MED-SUV project

    NASA Astrophysics Data System (ADS)

    Chowdhury, Tanvir Ahmed; Minet, Christian; Fritz, Thomas; Rodriguez Gonzalez, Fernando

    2015-04-01

    Volcanic unrest which produces a variety of geological and hydrological hazards is difficult to predict. Therefore it is important to monitor volcanoes continuously. The monitoring of active volcanoes requires the reliable measurement of surface deformation before, during and after volcanic activities. Besides the improvements of the understanding of geophysical processes underlying the volcanic systems of Vesuvius/ Campi Flegrei and Mt. Etna, one of the main goals of the MED-SUV (MEDiterranean SUpersite Volcanoes) project is to design a system for automatically monitoring ground deformations over active volcanoes. Space-borne synthetic aperture radar (SAR) interferometry (InSAR), persistent scatterer interferometry (PSI) and small baseline subset algorithm (SBAS) provide powerful tools for observing the surface changes with millimeter accuracy. All the mentioned techniques address the challenges by exploiting medium to large SAR image stacks. The generation of interferometric products constitutes a major effort in terms of processing and planning. It requires a high degree of automation, robustness and quality control of the overall process. As a consequence of these requirements and constrains, the Integrated Wide Area Processor (IWAP) developed at DLR is introduced in the framework of a remote sensing task of MED-SUV project. The IWAP has been conceived and designed to optimize the processing workflow in order to minimize the processing time. Moreover, a quality control concept has been developed and integrated in the workflow. The IWAP is structured into three parts: (i) firstly, preparation of an order file containing some configuration parameters and invokes the processor; (ii) secondly, upon request from the processor, the operator performs some manual interactions by means of visual interfaces; (iii) analysis of the final product supported by extensive product visualization. This visualization supports the interpretation of the results without the need of

  16. Spatial Modeling and Variability Analysis for Modeling and Prediction of Soil and Crop Canopy Coverage Using Multispectral Imagery from an Airborne Remote Sensing System

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Based on a previous study on an airborne remote sensing system with automatic camera stabilization for crop management, multispectral imagery was acquired using the MS-4100 multispectral camera at different flight altitudes over a 115 ha cotton field. After the acquired images were geo-registered an...

  17. Advanced digital SAR processing study

    NASA Technical Reports Server (NTRS)

    Martinson, L. W.; Gaffney, B. P.; Liu, B.; Perry, R. P.; Ruvin, A.

    1982-01-01

    A highly programmable, land based, real time synthetic aperture radar (SAR) processor requiring a processed pixel rate of 2.75 MHz or more in a four look system was designed. Variations in range and azimuth compression, number of looks, range swath, range migration and SR mode were specified. Alternative range and azimuth processing algorithms were examined in conjunction with projected integrated circuit, digital architecture, and software technologies. The advaced digital SAR processor (ADSP) employs an FFT convolver algorithm for both range and azimuth processing in a parallel architecture configuration. Algorithm performace comparisons, design system design, implementation tradeoffs and the results of a supporting survey of integrated circuit and digital architecture technologies are reported. Cost tradeoffs and projections with alternate implementation plans are presented.

  18. The development of a power spectral density processor for C and L band airborne radar scatterometer sensor systems

    NASA Technical Reports Server (NTRS)

    Harrison, D. A., III; Chladek, J. T.

    1983-01-01

    A real-time signal processor was developed for the NASA/JSC L-and C-band airborne radar scatterometer sensor systems. The purpose of the effort was to reduce ground data processing costs. Conversion of two quadrature channels of data (like and cross polarized) was made to obtain Power Spectral Density (PSD) values. A chirp-z transform (CZT) approach was used to filter the Doppler return signal and improved high frequency and angular resolution was realized. The processors have been tested with record signals and excellent results were obtained. CZT filtering can be readily applied to scatterometers operating at other wavelengths by altering the sample frequency. The design of the hardware and software and the results of the performance tests are described in detail.

  19. Detection of coastal and submarine discharge on the Florida Gulf Coast with an airborne thermal-infrared mapping system

    USGS Publications Warehouse

    Raabe, Ellen; Stonehouse, David; Ebersol, Kristin; Holland, Kathryn; Robbins, Lisa

    2011-01-01

    Along the Gulf Coast of Florida north of Tampa Bay lies a region characterized by an open marsh coast, low topographic gradient, water-bearing limestone, and scattered springs. The Floridan aquifer system is at or near land surface in this region, discharging water at a consistent 70-72°F. The thermal contrast between ambient water and aquifer discharge during winter months can be distinguished using airborne thermal-infrared imagery. An airborne thermal-infrared mapping system was used to collect imagery along 126 miles of the Gulf Coast from Jefferson to Levy County, FL, in March 2009. The imagery depicts a large number of discharge locations and associated warm-water plumes in ponds, creeks, rivers, and nearshore waters. A thermal contrast of 6°F or more was set as a conservative threshold for identifying sites, statistically significant at the 99% confidence interval. Almost 900 such coastal and submarine-discharge locations were detected, averaging seven to nine per mile along this section of coast. This represents approximately one hundred times the number of previously known discharge sites in the same area. Several known coastal springs in Taylor and Levy Counties were positively identified with the imagery and were used to estimate regional discharge equivalent to one 1st-order spring, discharging 100 cubic feet per second or more, for every two miles of coastline. The number of identified discharge sites is a conservative estimate and may represent two-thirds of existing features due to low groundwater levels at time of overflight. The role of aquifer discharge in coastal and estuarine health is indisputable; however, mapping and quantifying discharge in a complex karst environment can be an elusive goal. The results of this effort illustrate the effectiveness of the instrument and underscore the influence of coastal springs along this stretch of the Florida coast.

  20. Reflectors for SAR performance testing.

    SciTech Connect

    Doerry, Armin Walter

    2008-01-01

    Synthetic Aperture Radar (SAR) performance testing and estimation is facilitated by observing the system response to known target scene elements. Trihedral corner reflectors and other canonical targets play an important role because their Radar Cross Section (RCS) can be calculated analytically. However, reflector orientation and the proximity of the ground and mounting structures can significantly impact the accuracy and precision with which measurements can be made. These issues are examined in this report.