Science.gov

Sample records for radar maps

  1. Kuiper Belt Mapping Radar

    NASA Technical Reports Server (NTRS)

    Freeman, A.; Nilsen, E.

    2001-01-01

    Since their initial discovery in 1992, to date only a relatively small number of Kuiper Belt Objects (KBO's) have been discovered. Current detection techniques rely on frame-to-frame comparisons of images collected by optical telescopes such as Hubble, to detect KBO's as they move against the background stellar field. Another technique involving studies of KBO's through occultation of known stars has been proposed. Such techniques are serendipitous, not systematic, and may lead to an inadequate understanding of the size, range, and distribution of KBO's. In this paper, a future Kuiper Belt Mapping Radar is proposed as a solution to the problem of mapping the size distribution, extent, and range of KBO's. This approach can also be used to recover radar albedo and object rotation rates. Additional information is contained in the original extended abstract.

  2. Recent advances in geologic mapping by radar

    NASA Technical Reports Server (NTRS)

    Farr, T. G.

    1984-01-01

    Quantitative techniques are available which allow the analysis of SAR images for the derivation of geological surface and process data. In conjunction with calibrated radar sensors operating at several incidence angles, wavelengths, and polarizations, the compilation of multiparameter radar signatures of lithological and geomorphic units can accordingly proceed for geological mapping in unknown areas. While radar image tone can be used in arid zones to derive surface micromorphology, heavily vegetated tropical regions require the analysis of radar image texture by means of Fourier techniques which decompose the image into bandpasses that represent different scales of texture.

  3. VHF radar measurements during MAP/WINE

    NASA Technical Reports Server (NTRS)

    Czechowsky, P.; Klostermeyer, J.; Ruster, R.; Schmidt, G.; Rottger, J.

    1983-01-01

    Sensitive Doppler radars which operate in the very high frequency (VHF) band, usually near 50 MHz can measure profiles of background winds, tides, atmospheric gravity waves and turbulence at tropospheric, stratospheric and mesospheric heights. Their ability to observe simultaneously large and small-scale processes makes them unique instruments for studying not only each process separately but also their nonlinear interactions. The mobile VHF radar to be used during the MAP/WINE campaign on Andoya is a modified version of the SOUSY VHF radar being in operation for six years in the Harz Mountains.

  4. Wetland mapping with imaging radar

    NASA Technical Reports Server (NTRS)

    Waite, W. P.; Macdonald, H. C.; Kaupp, V. H.; Demarcke, J. S.

    1981-01-01

    An analysis of Seasat radar imagery is presented to identify the radar signature of vegetation-covered water surfaces. Imagery taken on Aug. 21, 1978 displayed anomalously high returns over swamp lands near Lafayette, LA. Landsat scans of the area two days later revealed uniform vegetation cover in the area, and ground examination found the area to be filled with cypress trees in swamps. Similar results were obtained during an overflight above a region of southeast Arkansas. Mechanisms producing the high degree of reflectance are explored, and the possibility that the strong return is due to an interaction of the vegetation cover and the specular water surface underneath is mentioned. Further studies to identify the exact mechanisms producing the anomalous returns are recommended, as well as optimization of the viewing angle for general classes of vegetation density.

  5. NASA's DC-8 With Rain Mapping Radar

    NASA Technical Reports Server (NTRS)

    1999-01-01

    In a joint venture between NASA and Japan's NASDA, scientists have been using satellites, airplanes, and boats to measure rain physics in and under thunderstorms over open water. This Quick Time movie shows NASA's DC-8 jet with the instruments like the airborne rain mapping radar, i.e., the Advanced Microwave Precipitation Radiometer (AMPR) and a lightening imaging sensor. Earth science and weather studies are an important ongoing function of NASA and its affiliates.

  6. Integrating Radar Image Data with Google Maps

    NASA Technical Reports Server (NTRS)

    Chapman, Bruce D.; Gibas, Sarah

    2010-01-01

    A public Web site has been developed as a method for displaying the multitude of radar imagery collected by NASA s Airborne Synthetic Aperture Radar (AIRSAR) instrument during its 16-year mission. Utilizing NASA s internal AIRSAR site, the new Web site features more sophisticated visualization tools that enable the general public to have access to these images. The site was originally maintained at NASA on six computers: one that held the Oracle database, two that took care of the software for the interactive map, and three that were for the Web site itself. Several tasks were involved in moving this complicated setup to just one computer. First, the AIRSAR database was migrated from Oracle to MySQL. Then the back-end of the AIRSAR Web site was updated in order to access the MySQL database. To do this, a few of the scripts needed to be modified; specifically three Perl scripts that query that database. The database connections were then updated from Oracle to MySQL, numerous syntax errors were corrected, and a query was implemented that replaced one of the stored Oracle procedures. Lastly, the interactive map was designed, implemented, and tested so that users could easily browse and access the radar imagery through the Google Maps interface.

  7. Space Radar Image of Raco Biomass Map

    NASA Technical Reports Server (NTRS)

    1999-01-01

    This biomass map of the Raco, Michigan, area was produced from data acquired by the Spaceborne Imaging Radar C/X-Band Synthetic Aperture Radar (SIR-C/X-SAR) onboard space shuttle Endeavour. Biomass is the amount of plant material on an area of Earth's surface. Radar can directly sense the quantity and organizational structure of the woody biomass in the forest. Science team members at the University of Michigan used the radar data to estimate the standing biomass for this Raco site in the Upper Peninsula of Michigan. Detailed surveys of 70 forest stands will be used to assess the accuracy of these techniques. The seasonal growth of terrestrial plants, and forests in particular, leads to the temporary storage of large amounts of carbon, which could directly affect changes in global climate. In order to accurately predict future global change, scientists need detailed information about current distribution of vegetation types and the amount of biomass present around the globe. Optical techniques to determine net biomass are frustrated by chronic cloud-cover. Imaging radar can penetrate through cloud-cover with negligible signal losses. Spaceborne Imaging Radar-C and X-Synthetic Aperture Radar (SIR-C/X-SAR) is part of NASA's Mission to Planet Earth. The radars illuminate Earth with microwaves allowing detailed observations at any time, regardless of weather or sunlight conditions. SIR-C/X-SAR uses three microwave wavelengths: L-band (24 cm), C-band (6 cm) and X-band (3 cm). The multi-frequency data will be used by the international scientific community to better understand the global environment and how it is changing. The SIR-C/X-SAR data, complemented by aircraft and ground studies, will give scientists clearer insights into those environmental changes which are caused by nature and those changes which are induced by human activity. SIR-C was developed by NASA's Jet Propulsion Laboratory. X-SAR was developed by the Dornier and Alenia Spazio companies for the German

  8. Space Radar Image of Raco Vegetation Map

    NASA Technical Reports Server (NTRS)

    1999-01-01

    This is a vegetation map of the Raco, Michigan area produced from data acquired by the Spaceborne Imaging Radar C/X-Band Synthetic Aperture Radar (SIR-C/X-SAR) onboard space shuttle Endeavour. The radar image, taken on April 9, 1994, has been used by science team members at the University of Michigan to produce detailed map of land cover. This image is centered at 46.4 degrees north latitude and 84.9 degrees west longitude. The imaged area is approximately 24 by 32 kilometers (15 by 20 miles). The Raco airport, which is a decommissioned military base, is easily identified by its triangular runway structure. An edge of Lake Superior, approximately 44 kilometers (27 miles) west of Sault Sainte Marie, appears in the top right of the image. In this land cover map each 30- by 30-meter (98- by 98-foot) spot is identified as either a water surface, bare ground, short vegetation, deciduous forest, lowland conifers or upland conifers. Different types of ground cover have different effects on Earth's chemical, water and energy cycles. By cataloguing ground cover in an area, scientists expect to better understand the processes of these cycles in a specific area. Spaceborne Imaging Radar-C and X-Synthetic Aperture Radar (SIR-C/X-SAR) is part of NASA's Mission to Planet Earth. The radars illuminate Earth with microwaves allowing detailed observations at any time, regardless of weather or sunlight conditions. SIR-C/X-SAR uses three microwave wavelengths: L-band (24 cm), C-band (6 cm) and X-band (3 cm). The multi-frequency data will be used by the international scientific community to better understand the global environment and how it is changing. The SIR-C/X-SAR data, complemented by aircraft and ground studies, will give scientists clearer insights into those environmental changes which are caused by nature and those changes which are induced by human activity. SIR-C was developed by NASA's Jet Propulsion Laboratory. X-SAR was developed by the Dornier and Alenia Spazio

  9. The TOPSAR interferometric radar topographic mapping instrument

    NASA Astrophysics Data System (ADS)

    Zebker, Howard A.

    1991-08-01

    We have augmented the NASA DC-8 Airborne Synthetic Aperture Radar (AIRSAR) instrument with a pair of C-band antennas displaced across the track to form an interferometer sensitive to topographic variations of the Earth's surface. The antennas were developed by Alenia Spazio under the sponsorship of the Italian Space Agency (ASI), and the AIRSAR instrument and modifications to it supporting TOPSAR were sponsored by NASA. A new data processor was developed at JPL for producing the topographic maps. As of May 1991, one engineering flight line over San Francisco, CA was reduced to a cartographically rectified topographic map. Analysis of the results indicates that statistical errors are in the range of 2 to 4 m, while systematic effects due to aircraft motion are in the range of 6 to 12 m. Future aircraft motion compensation algorithms should reduce the systematic variations to near zero, while the statistical errors could likely be reduced to 2 m or less with some processor improvements.

  10. Small scale thematic mapping - A case for radar imagery

    NASA Technical Reports Server (NTRS)

    Henderson, F. M.

    1974-01-01

    Small scale thematic maps (1:250,000 and smaller) of physical and cultural phenomena manifested on the landscape are a major concern to scientists and investigators in diverse disciplines. A strip of K-band radar imagery consisting of a traverse from eastern Minnesota to northern Utah was employed to evaluate the potential of radar imagery for small scale land use mapping. In the course of this investigation, it was discovered that certain borders derived from radar imagery were compatible with borders found on the nonland use thematic maps used for comparison. Specifically, numerous borders and regions of small scale maps of landforms, soils, vegetation, and geology are found to be similar to the radar land use regions. Although far from conclusive it appears that radar imagery can be employed in the small scale mapping of landforms and possibly for mapping physiognomic or economic vegetation.

  11. Radar for small-scale land-use mapping

    NASA Technical Reports Server (NTRS)

    Henderson, F. M.

    1975-01-01

    Small-scale (1:250,000 and smaller) land-use maps are a major concern not only to geographers but also to national and regional planners. Unfortunately, such maps are usually out of date by the time they are printed. An interpretation key consisting of five physical and cultural characteristics of the environment evident on radar imagery is used to create land-use regions. Regions and borders interpreted from radar are compared with those found on two existing land-use maps created by traditional methods. Radar imagery can be used to create a small-scale land-use map with regions comparable to those found on existing land-use maps. However, the radar regions depict something more than land use and should be termed rural landscape regions.

  12. Demonstration of radar reflector detection and ground clutter suppression using airborne weather and mapping radar

    NASA Technical Reports Server (NTRS)

    Anderson, D. J.; Bull, J. S.; Chisholm, J. P.

    1982-01-01

    A navigation system which utilizes minimum ground-based equipment is especially advantageous to helicopters, which can make off-airport landings. Research has been conducted in the use of weather and mapping radar to detect large radar reflectors overland for navigation purposes. As initial studies have not been successful, investigations were conducted regarding a new concept for the detection of ground-based radar reflectors and eliminating ground clutter, using a device called an echo processor (EP). A description is presented of the problems associated with detecting radar reflectors overland, taking into account the EP concept and the results of ground- and flight-test investigations. The echo processor concept was successfully demonstrated in detecting radar reflectors overland in a high-clutter environment. A radar reflector target size of 55 dBsm was found to be adequate for detection in an urban environment.

  13. Mapping wintering waterfowl distributions using weather surveillance radar

    USGS Publications Warehouse

    Buler, Jeffrey J.; Randall, Lori A.; Fleskes, Joseph P.; Barrow, Wylie C.; Bogart, Tianna; Kluver, Daria

    2012-01-01

    The current network of weather surveillance radars within the United States readily detects flying birds and has proven to be a useful remote-sensing tool for ornithological study. Radar reflectivity measures serve as an index to bird density and have been used to quantitatively map landbird distributions during migratory stopover by sampling birds aloft at the onset of nocturnal migratory flights. Our objective was to further develop and validate a similar approach for mapping wintering waterfowl distributions using weather surveillance radar observations at the onset of evening flights. We evaluated data from the Sacramento, CA radar (KDAX) during winters 1998–1999 and 1999–2000. We determined an optimal sampling time by evaluating the accuracy and precision of radar observations at different times during the onset of evening flight relative to observed diurnal distributions of radio-marked birds on the ground. The mean time of evening flight initiation occurred 23 min after sunset with the strongest correlations between reflectivity and waterfowl density on the ground occurring almost immediately after flight initiation. Radar measures became more spatially homogeneous as evening flight progressed because birds dispersed from their departure locations. Radars effectively detected birds to a mean maximum range of 83 km during the first 20 min of evening flight. Using a sun elevation angle of -5° (28 min after sunset) as our optimal sampling time, we validated our approach using KDAX data and additional data from the Beale Air Force Base, CA (KBBX) radar during winter 1998–1999. Bias-adjusted radar reflectivity of waterfowl aloft was positively related to the observed diurnal density of radio-marked waterfowl locations on the ground. Thus, weather radars provide accurate measures of relative wintering waterfowl density that can be used to comprehensively map their distributions over large spatial extents.

  14. Mapping wintering waterfowl distributions using weather surveillance radar.

    PubMed

    Buler, Jeffrey J; Randall, Lori A; Fleskes, Joseph P; Barrow, Wylie C; Bogart, Tianna; Kluver, Daria

    2012-01-01

    The current network of weather surveillance radars within the United States readily detects flying birds and has proven to be a useful remote-sensing tool for ornithological study. Radar reflectivity measures serve as an index to bird density and have been used to quantitatively map landbird distributions during migratory stopover by sampling birds aloft at the onset of nocturnal migratory flights. Our objective was to further develop and validate a similar approach for mapping wintering waterfowl distributions using weather surveillance radar observations at the onset of evening flights. We evaluated data from the Sacramento, CA radar (KDAX) during winters 1998-1999 and 1999-2000. We determined an optimal sampling time by evaluating the accuracy and precision of radar observations at different times during the onset of evening flight relative to observed diurnal distributions of radio-marked birds on the ground. The mean time of evening flight initiation occurred 23 min after sunset with the strongest correlations between reflectivity and waterfowl density on the ground occurring almost immediately after flight initiation. Radar measures became more spatially homogeneous as evening flight progressed because birds dispersed from their departure locations. Radars effectively detected birds to a mean maximum range of 83 km during the first 20 min of evening flight. Using a sun elevation angle of -5° (28 min after sunset) as our optimal sampling time, we validated our approach using KDAX data and additional data from the Beale Air Force Base, CA (KBBX) radar during winter 1998-1999. Bias-adjusted radar reflectivity of waterfowl aloft was positively related to the observed diurnal density of radio-marked waterfowl locations on the ground. Thus, weather radars provide accurate measures of relative wintering waterfowl density that can be used to comprehensively map their distributions over large spatial extents.

  15. Mapping Wintering Waterfowl Distributions Using Weather Surveillance Radar

    PubMed Central

    Buler, Jeffrey J.; Randall, Lori A.; Fleskes, Joseph P.; Barrow, Wylie C.; Bogart, Tianna; Kluver, Daria

    2012-01-01

    The current network of weather surveillance radars within the United States readily detects flying birds and has proven to be a useful remote-sensing tool for ornithological study. Radar reflectivity measures serve as an index to bird density and have been used to quantitatively map landbird distributions during migratory stopover by sampling birds aloft at the onset of nocturnal migratory flights. Our objective was to further develop and validate a similar approach for mapping wintering waterfowl distributions using weather surveillance radar observations at the onset of evening flights. We evaluated data from the Sacramento, CA radar (KDAX) during winters 1998–1999 and 1999–2000. We determined an optimal sampling time by evaluating the accuracy and precision of radar observations at different times during the onset of evening flight relative to observed diurnal distributions of radio-marked birds on the ground. The mean time of evening flight initiation occurred 23 min after sunset with the strongest correlations between reflectivity and waterfowl density on the ground occurring almost immediately after flight initiation. Radar measures became more spatially homogeneous as evening flight progressed because birds dispersed from their departure locations. Radars effectively detected birds to a mean maximum range of 83 km during the first 20 min of evening flight. Using a sun elevation angle of −5° (28 min after sunset) as our optimal sampling time, we validated our approach using KDAX data and additional data from the Beale Air Force Base, CA (KBBX) radar during winter 1998–1999. Bias-adjusted radar reflectivity of waterfowl aloft was positively related to the observed diurnal density of radio-marked waterfowl locations on the ground. Thus, weather radars provide accurate measures of relative wintering waterfowl density that can be used to comprehensively map their distributions over large spatial extents. PMID:22911816

  16. Contour-Mapping Synthetic-Aperture Radar

    NASA Technical Reports Server (NTRS)

    Goldstein, R. M.; Caro, E. R.; Wu, C.

    1985-01-01

    Airborne two-antenna synthetic-aperture-radar (SAR) interferometric system provides data processed to yield terrain elevation as well as reflectedintensity information. Relative altitudes of terrain points measured to within error of approximately 25 m.

  17. Mapping diverse forest cover with multipolarization airborne radar

    NASA Technical Reports Server (NTRS)

    Ford, J. P.; Wickland, D. E.; Sharitz, R. R.

    1985-01-01

    Imaging radar backscatter in continuously forested areas contains information about the forest canopy; it also contains data about topography, landforms, and terrain texture. For purposes of radar image interpretation and geologic mapping researchers were interested in identifying and separating forest canopy effects from geologic or geomorphic effects on radar images. The objectives of this investigation was to evaluate forest canopy variables in multipolarization radar images under conditions where geologic and topographic variables are at a minimum. A subsidiary objective was to compare the discriminatory capabilities of the radar images with corresponding optical images of similar spatial resolution. It appears that the multipolarization images discriminate variation in tree density, but no evidence was found for discrimination between evergreen and deciduous forest types.

  18. Suppression Of Range Sidelobes In Spaceborne Rain-Mapping Radar

    NASA Technical Reports Server (NTRS)

    Im, Eastwood; Wilson, William J.; Li, Fuk K.; Tanner, Alan B.; Durden, Stephen L.; Denning, Richard F.

    1994-01-01

    Adequate suppression of range sidelobes in chirp pulse-compression radar system for spaceborne rain-mapping application demonstrated in operation of aircraft version of system. Radar system operates at center frequency of 13.8 GHz, developed for operation aboard NASA DC-8 aircraft to measure vertical rainfall-rate profiles and rain-cell dimensions. Sidelobes suppressed by at least 55 dB. Technique applied to other frequencies, therefore, useful in other radar systems in which low sidelobes at mid to far range needed.

  19. Collection of Magellan Venus radar mapping results

    NASA Astrophysics Data System (ADS)

    1991-03-01

    Through computer animation several geological features of Venus are presented in this video. The Sif Mons, a 1.2 mile high volcano and the Gula Mons, a 1.8 mile high volcano are shown. Also, radar images of a rift valley, several impact craters, and a corona can be seen. The video ends with a northeast view of Eistla Regio.

  20. Planetary radar studies. [radar mapping of the Moon and radar signatures of lunar and Venus craters

    NASA Technical Reports Server (NTRS)

    Thompson, T. W.; Cutts, J. A.

    1981-01-01

    Progress made in studying the evolution of Venusian craters and the evolution of infrared and radar signatures of lunar crater interiors is reported. Comparison of radar images of craters on Venus and the Moon present evidence for a steady state Venus crater population. Successful observations at the Arecibo Observatory yielded good data on five nights when data for a mix of inner and limb areas were acquired. Lunar craters with radar bright ejects are discussed. An overview of infrared radar crater catalogs in the data base is included.

  1. Science considerations for an orbital radar mapping mission to Venus

    NASA Technical Reports Server (NTRS)

    Wychgram, D. C.

    1974-01-01

    A radar mapping mission to Venus is under consideration by NASA for the 1980s. The science objectives of the mission are to determine the geologic history of the planet; map the major topographic features and provide limited detailed geologic and terrain analysis of potential probe landing sites. Because of the thick Venusian atmosphere, a synthetic-aperture side-looking radar system has been selected as the most practical remote sensing instruments to use. Topographic data are the most useful for achieving the science goals of the mission. The radar system variables and mission parameters must be specified to maximize topographic data returns while being compatible with engineering and cost restraints. A baseline imaging resolution of 100 meters, with ability to obtain some higher-resolution coverage, is acceptable. Total planet coverage is desirable but the primary science objectives can be achieved if at least one entire hemisphere is imaged.

  2. Localization and Mapping Using Only a Rotating FMCW Radar Sensor

    PubMed Central

    Vivet, Damien; Checchin, Paul; Chapuis, Roland

    2013-01-01

    Rotating radar sensors are perception systems rarely used in mobile robotics. This paper is concerned with the use of a mobile ground-based panoramic radar sensor which is able to deliver both distance and velocity of multiple targets in its surrounding. The consequence of using such a sensor in high speed robotics is the appearance of both geometric and Doppler velocity distortions in the collected data. These effects are, in the majority of studies, ignored or considered as noise and then corrected based on proprioceptive sensors or localization systems. Our purpose is to study and use data distortion and Doppler effect as sources of information in order to estimate the vehicle's displacement. The linear and angular velocities of the mobile robot are estimated by analyzing the distortion of the measurements provided by the panoramic Frequency Modulated Continuous Wave (FMCW) radar, called IMPALA. Without the use of any proprioceptive sensor, these estimates are then used to build the trajectory of the vehicle and the radar map of outdoor environments. In this paper, radar-only localization and mapping results are presented for a ground vehicle moving at high speed. PMID:23567523

  3. Forest Biomass Mapping From Lidar and Radar Synergies

    NASA Technical Reports Server (NTRS)

    Sun, Guoqing; Ranson, K. Jon; Guo, Z.; Zhang, Z.; Montesano, P.; Kimes, D.

    2011-01-01

    The use of lidar and radar instruments to measure forest structure attributes such as height and biomass at global scales is being considered for a future Earth Observation satellite mission, DESDynI (Deformation, Ecosystem Structure, and Dynamics of Ice). Large footprint lidar makes a direct measurement of the heights of scatterers in the illuminated footprint and can yield accurate information about the vertical profile of the canopy within lidar footprint samples. Synthetic Aperture Radar (SAR) is known to sense the canopy volume, especially at longer wavelengths and provides image data. Methods for biomass mapping by a combination of lidar sampling and radar mapping need to be developed. In this study, several issues in this respect were investigated using aircraft borne lidar and SAR data in Howland, Maine, USA. The stepwise regression selected the height indices rh50 and rh75 of the Laser Vegetation Imaging Sensor (LVIS) data for predicting field measured biomass with a R(exp 2) of 0.71 and RMSE of 31.33 Mg/ha. The above-ground biomass map generated from this regression model was considered to represent the true biomass of the area and used as a reference map since no better biomass map exists for the area. Random samples were taken from the biomass map and the correlation between the sampled biomass and co-located SAR signature was studied. The best models were used to extend the biomass from lidar samples into all forested areas in the study area, which mimics a procedure that could be used for the future DESDYnI Mission. It was found that depending on the data types used (quad-pol or dual-pol) the SAR data can predict the lidar biomass samples with R2 of 0.63-0.71, RMSE of 32.0-28.2 Mg/ha up to biomass levels of 200-250 Mg/ha. The mean biomass of the study area calculated from the biomass maps generated by lidar- SAR synergy 63 was within 10% of the reference biomass map derived from LVIS data. The results from this study are preliminary, but do show the

  4. Assistant for Analyzing Tropical-Rain-Mapping Radar Data

    NASA Technical Reports Server (NTRS)

    James, Mark

    2006-01-01

    A document is defined that describes an approach for a Tropical Rain Mapping Radar Data System (TDS). TDS is composed of software and hardware elements incorporating a two-frequency spaceborne radar system for measuring tropical precipitation. The TDS would be used primarily in generating data products for scientific investigations. The most novel part of the TDS would be expert-system software to aid in the selection of algorithms for converting raw radar-return data into such primary observables as rain rate, path-integrated rain rate, and surface backscatter. The expert-system approach would address the issue that selection of algorithms for processing the data requires a significant amount of preprocessing, non-intuitive reasoning, and heuristic application, making it infeasible, in many cases, to select the proper algorithm in real time. In the TDS, tentative selections would be made to enable conversions in real time. The expert system would remove straightforwardly convertible data from further consideration, and would examine ambiguous data, performing analysis in depth to determine which algorithms to select. Conversions performed by these algorithms, presumed to be correct, would be compared with the corresponding real-time conversions. Incorrect real-time conversions would be updated using the correct conversions.

  5. Mapping of glacial landforms from Seasat radar images

    NASA Technical Reports Server (NTRS)

    Ford, J. P.

    1984-01-01

    Glacial landforms in the drumlin drift belt of Ireland and the Alaska Range can be identified and mapped from Seasat synthetic-aperture radar (SAR) images. Drumlins cover 60 percent of the Ireland scene. The width/length ratio of individual drumlins can be measured on the SAR images, allowing regional differences in drumlin shape to be mapped. This cannot be done with corresponding Landsat multispectral scanner (MSS) images because of lower spatial resolution and because of shadowing effects that vary seasonally. The Alaska scene shows the extent and nature of morphological features such as medial and lateral moraines, stagnant ice, and fluted ground moraine in glaciated valleys. Perception of these features on corresponding Landsat MSS images is limited by seasonal diffrences in solar illumination. Because SAR is not affected by such differences or by cloud cover, it is particularly well suited for monitoring glacial movement. The disadvantage of distorted high-relief features on Seasat SAR images can be reduced in future SAR systems by modifying the radar illumination geometry.

  6. New formulation for interferometric synthetic aperture radar for terrain mapping

    SciTech Connect

    Jakowatz, C.V. Jr.; Wahl, D.E.; Eichel, P.H.; Thompson, P.A.

    1994-04-01

    The subject of interferometric synthetic aperture radar (IFSAR) for high-accuracy terrain elevation mapping continues to gain importance in the arena of radar signal processing. Applications to problems in precision terrain-aided guidance and automatic target recognition, as well as a variety of civil applications, are being studied by a number of researchers. Not unlike many other areas of SAR processing, the subject of IFSAR can at first glance appear to be somewhat mysterious. In this paper we show how the mathematics of IFSAR for terrain elevation mapping using a pair of spotlight mode SAR collections can be derived in a very straightforward manner. Here, we employ an approach that relies entirely on three-dimensional Fourier transforms, and utilizes no reference to range equations or Doppler concepts. The result is a simplified explanation of the fundamentals of interferometry, including an easily-seen link between image domain phase difference and terrain elevation height. The derivation builds upon previous work by the authors in which a framework for spotlight mode SAR image formation based on an analogy to three-dimensional computerized axial tomography (CAT) was developed. After outlining the major steps in the mathematics, we show how a computer simulator which utilizes three-dimensional Fourier transforms can be constructed that demonstrates all of the major aspects of IFSAR from spotlight mode collections.

  7. Mapping the Upper Subsurface of MARS Using Radar Polarimetry

    NASA Technical Reports Server (NTRS)

    Carter, L. M.; Rincon, R.; Berkoski, L.

    2012-01-01

    Future human exploration of Mars will require detailed knowledge of the surface and upper several meters of the subsurface in potential landing sites. Likewise, many of the Planetary Science Decadal Survey science goals, such as understanding the history of Mars climate change, determining how the surface was altered through processes like volcanism and fluvial activity, and locating regions that may have been hospitable to life in the past, would be significantly advanced through mapping of the upper meters of the surface. Synthetic aperture radar (SAR) is the only remote sensing technique capable of penetrating through meters of material and imaging buried surfaces at high (meters to tens-of-meters) spatial resolution. SAR is capable of mapping the boundaries of buried units and radar polarimetry can provide quantitative information about the roughness of surface and subsurface units, depth of burial of stratigraphic units, and density of materials. Orbital SAR systems can obtain broad coverage at a spatial scale relevant to human and robotic surface operations. A polarimetric SAR system would greatly increase the safety and utility of future landed systems including sample caching.

  8. Flash flood area mapping utilising SENTINEL-1 radar data

    NASA Astrophysics Data System (ADS)

    Psomiadis, Emmanouil

    2016-10-01

    The new European Observatory radar data of polar orbiting satellite system Sentinel-1 provide a continuous and systematic data acquisition, enabling flood events monitoring and mapping. The study area is the basin of Sperchios River in Fthiotida Prefecture, Central Greece, having an increased ecological, environmental and socio-economic interest. The catchment area and especially the river delta, faces several problems and threats caused by anthropogenic activities and natural processes. The geomorphology of Sperchios catchment area and the drainage network formation provoke the creation of floods. A large flash flood event took place in late January early February 2015 following an intense and heavy rainfall that occurred in the area. Two space born radar images, obtained from Sentinel-1 covering the same area, one before and another one during the flood event, were processed. Two different methods were utilized so as to produce flood hazard maps, which demonstrate the inundated areas. The results of the two methods were similar and the flooded area was detected and delineated ideally.

  9. Urban Underground Pipelines Mapping Using Ground Penetrating Radar

    NASA Astrophysics Data System (ADS)

    Jaw, S. W.; M, Hashim

    2014-02-01

    Underground spaces are now being given attention to exploit for transportation, utilities, and public usage. The underground has become a spider's web of utility networks. Mapping of underground utility pipelines has become a challenging and difficult task. As such, mapping of underground utility pipelines is a "hit-and-miss" affair, and results in many catastrophic damages, particularly in urban areas. Therefore, this study was conducted to extract locational information of the urban underground utility pipeline using trenchless measuring tool, namely ground penetrating radar (GPR). The focus of this study was to conduct underground utility pipeline mapping for retrieval of geometry properties of the pipelines, using GPR. In doing this, a series of tests were first conducted at the preferred test site and real-life experiment, followed by modeling of field-based model using Finite-Difference Time-Domain (FDTD). Results provide the locational information of underground utility pipelines associated with its mapping accuracy. Eventually, this locational information of the underground utility pipelines is beneficial to civil infrastructure management and maintenance which in the long term is time-saving and critically important for the development of metropolitan areas.

  10. Radar mapping of lunar cryptomaria east of Orientale basin

    NASA Astrophysics Data System (ADS)

    Campbell, Bruce A.; Hawke, B. Ray

    2005-09-01

    Lunar cryptomare deposits represent early basaltic volcanic material that has been mantled by or incorporated into highland-rich ejecta from basin- or crater-forming impacts. Mapping these buried basalts is important for understanding regional stratigraphy and the history and extent of lunar volcanism. We use new 70 cm wavelength radar images, collected using Arecibo Observatory and the Green Bank Telescope, and Clementine data to study cryptomaria east of Orientale basin. Earlier multispectral analyses showed that mare material is mixed with the highland terrain along the western margin of Oceanus Procellarum, leading to a detectable increase in the FeO and TiO2 abundance of the regolith surface. The highland margin of western Procellarum is also characterized by low 70 cm radar returns, consistent with an increased regolith loss tangent due to ilmenite in the mare-derived material. The low 70 cm radar echo, however, persists well to the west of the mixed zone evident in multispectral data and includes the region surrounding Cruger crater. It is likely that mare basalt, or a mixed zone of mare and highland material, exists at depth across the region and only reaches the visible surface near the western Procellarum margin. The plausible depth to this mixed zone is dependent upon the loss tangent of the overlying ``pure'' highland ejecta. If Orientale ejecta is primarily low-loss anorthosite, then the mixed zone could lie at depths of up to several tens of meters. We propose that pre-Orientale mare deposits flooded the region between Cruger, Grimaldi, and Oceanus Procellarum and also patches west and northwest of Humorum basin. The total area of these deposits represents 178 × 103 km2, or an additional ~0.5% of the lunar surface, covered by mare basalts.

  11. Mapping of Titan: Results from the first Titan radar passes

    USGS Publications Warehouse

    Stofan, E.R.; Lunine, J.I.; Lopes, R.; Paganelli, F.; Lorenz, R.D.; Wood, C.A.; Kirk, R.; Wall, S.; Elachi, C.; Soderblom, L.A.; Ostro, S.; Janssen, M.; Radebaugh, J.; Wye, L.; Zebker, H.; Anderson, Y.; Allison, M.; Boehmer, R.; Callahan, P.; Encrenaz, P.; Flamini, E.; Francescetti, G.; Gim, Y.; Hamilton, G.; Hensley, S.; Johnson, W.T.K.; Kelleher, K.; Muhleman, D.; Picardi, G.; Posa, F.; Roth, L.; Seu, R.; Shaffer, S.; Stiles, B.; Vetrella, S.; West, R.

    2006-01-01

    The first two swaths collected by Cassini's Titan Radar Mapper were obtained in October of 2004 (Ta) and February of 2005 (T3). The Ta swath provides evidence for cryovolcanic processes, the possible occurrence of fluvial channels and lakes, and some tectonic activity. The T3 swath has extensive areas of dunes and two large impact craters. We interpret the brightness variations in much of the swaths to result from roughness variations caused by fracturing and erosion of Titan's icy surface, with additional contributions from a combination of volume scattering and compositional variations. Despite the small amount of Titan mapped to date, the significant differences between the terrains of the two swaths suggest that Titan is geologically complex. The overall scarcity of impact craters provides evidence that the surface imaged to date is relatively young, with resurfacing by cryovolcanism, fluvial erosion, aeolian erosion, and likely atmospheric deposition of materials. Future radar swaths will help to further define the nature of and extent to which internal and external processes have shaped Titan's surface. ?? 2006 Elsevier Inc. All rights reserved.

  12. Snow mapping in alpine regions with synthetic aperture radar

    SciTech Connect

    Shi, J.; Dozier, J. ); Rott, H. . Inst. for Meteorology and Geophysics)

    1994-01-01

    For climatological and hydrological investigations, the areas covered by snow and glacial ice are important parameters. Active microwave sensors can discriminate snow from other surfaces in all weather conditions, and their spatial resolution is compatible with the topographic variation in alpine regions. Using data acquired with the NASA AIRSAR in the Oetztal Alps in 1989 and 1991, the authors examine the usage of synthetic aperture radar (SAR) to map snow- and glacier-covered areas. By comparing polarimetric SAR data to images from the Landsat Thematic Mapper obtained under clear conditions one week after the SAR flight, they find that SAR data at 5.3 GHz (C-band) can discriminate between areas covered by snow from those that are ice-free. However, they are less suited to discrimination of glacier ice from snow and rock. The overall pixel-by-pixel accuracies--74% from VV polarization alone with topographic information, 76% from polarimetric SAR without any topographic information, and 79% from polarimetric SAR with topographic information--are high enough to justify the use of SAR as the data source in areas that are too cloud-covered to obtain data from the Thematic Mapper. This is especially true for snow discrimination, where accuracies exceed 80%, because mapping of a transient snow cover during a cloudy melt season is often difficult with an optical sensor. The AIRSAR survey was carried out in summer during a heavy rainstorm, when the snow surfaces were unusually rough.

  13. Application of shuttle imaging radar to geologic mapping

    NASA Technical Reports Server (NTRS)

    Labotka, T. C.

    1986-01-01

    Images from the Shuttle Imaging Radar - B (SIR-B) experiment covering the area of the Panamint Mountains, Death Valley, California, were examined in the field and in the laboratory to determine their usefulness as aids for geologic mapping. The covered area includes the region around Wildrose Canyon where rocks ranging in age from Precambrian to Cenozoic form a moderately rugged portion of the Panamint Mountains, including sharp ridges, broad alluviated upland valleys, and fault-bounded grabens. The results of the study indicate that the available SIR-B images of this area primarily illustrate variations in topography, except in the broadly alluviated areas of Panamint Valley and Death Valley where deposits of differing reflectivity can be recognized. Within the mountainous portion of the region, three textures can be discerned, each representing a different mode of topographic expression related to the erosion characteristics of the underlying bedrock. Regions of Precambrian bedrock have smooth slopes and sharp ridges with a low density of gullies. Tertiary monolithologic breccias have smooth, steep slopes with an intermediate density of gullies with rounded ridges. Tertiary fanglomerates have steep rugged slopes with numerous steep-sided gullies and knife-sharp ridges. The three topographic types reflect the consistancy and relative susceptibility to erosion of the bedrock; the three types can readily be recognized on topographic maps. At present, it has not been possible to distinguish on the SIR-B image of the mountainous terrain the type of bedrock, independent of the topographic expression.

  14. Radar response to vegetation. [soil moisture mapping via microwave backscattering

    NASA Technical Reports Server (NTRS)

    Ulaby, F. T.

    1975-01-01

    Active microwave measurements of vegetation backscatter were conducted to determine the utility of radar in mapping soil moisture through vegetation and mapping crop types. Using a truck-mounted boom, spectral response data were obtained for four crop types (corn, milo, soybeans, and alfalfa) over the 4-8 GHz frequency band, at incidence angles of 0 to 70 degrees in 10-degree steps, and for all four linear polarization combinations. Based on a total of 125 data sets covering a wide range of soil moisture, content, system design criteria are proposed for each of the aforementioned objectives. Quantitative soil moisture determination was best achieved at the lower frequency end of the 4-8 GHz band using HH polarized waves in the 5- to 15-degree incidence angle range. A combination of low and high frequency measurements are suggested for classifying crop types. For crop discrimination, a dual-frequency dual-polarization (VV and cross) system operating at incidence angles above 40 degrees is suggested.

  15. Mapping of forested wetland: use of Seasat radar images to complement conventional sources ( USA).

    USGS Publications Warehouse

    Place, J.L.

    1985-01-01

    Distinguishing forested wetland from dry forest using aerial photographs is handicapped because photographs often do not reveal the presence of water below tree canopies. Radar images obtained by the Seasat satellite reveal forested wetland as highly reflective patterns on the coastal plain between Maryland and Florida. Seasat radar images may complement aerial photographs for compiling maps of wetland. A test with experienced photointerpreters revealed that interpretation accuracy was significantly higher when using Seasat radar images than when using only conventional sources.-Author

  16. Radar Interferometer for Topographic Mapping of Glaciers and Ice Sheets

    NASA Technical Reports Server (NTRS)

    Moller, Delwyn K.; Sadowy, Gregory A.; Rignot, Eric J.; Madsen, Soren N.

    2007-01-01

    A report discusses Ka-band (35-GHz) radar for mapping the surface topography of glaciers and ice sheets at high spatial resolution and high vertical accuracy, independent of cloud cover, with a swath-width of 70 km. The system is a single- pass, single-platform interferometric synthetic aperture radar (InSAR) with an 8-mm wavelength, which minimizes snow penetration while remaining relatively impervious to atmospheric attenuation. As exhibited by the lower frequency SRTM (Shuttle Radar Topography Mission) AirSAR and GeoSAR systems, an InSAR measures topography using two antennas separated by a baseline in the cross-track direction, to view the same region on the ground. The interferometric combination of data received allows the system to resolve the pathlength difference from the illuminated area to the antennas to a fraction of a wavelength. From the interferometric phase, the height of the target area can be estimated. This means an InSAR system is capable of providing not only the position of each image point in along-track and slant range as with a traditional SAR but also the height of that point through interferometry. Although the evolution of InSAR to a millimeter-wave center frequency maximizes the interferometric accuracy from a given baseline length, the high frequency also creates a fundamental problem of swath coverage versus signal-to-noise ratio. While the length of SAR antennas is typically fixed by mass and stowage or deployment constraints, the width is constrained by the desired illuminated swath width. As the across-track beam width which sets the swath size is proportional to the wavelength, a fixed swath size equates to a smaller antenna as the frequency is increased. This loss of antenna size reduces the two-way antenna gain to the second power, drastically reducing the signal-to-noise ratio of the SAR system. This fundamental constraint of high-frequency SAR systems is addressed by applying digital beam-forming (DBF) techniques to

  17. Fine resolution topographic mapping of the Jovian moons: a Ka-band high resolution topographic mapping interferometric synthetic aperture radar

    NASA Technical Reports Server (NTRS)

    Madsen, Soren N.; Carsey, Frank D.; Turtle, Elizabeth P.

    2003-01-01

    The topographic data set obtained by MOLA has provided an unprecedented level of information about Mars' geologic features. The proposed flight of JIMO provides an opportunity to accomplish a similar mapping of and comparable scientific discovery for the Jovian moons through us of an interferometric imaging radar analogous to the Shuttle radar that recently generated a new topographic map of Earth. A Ka-band single pass across-track synthetic aperture radar (SAR) interferometer can provide very high resolution surface elevation maps. The concept would use two antennas mounted at the ends of a deployable boom (similar to the Shuttle Radar Topographic Mapper) extended orthogonal to the direction of flight. Assuming an orbit altitude of approximately 100 km and a ground velocity of approximately 1.5 km/sec, horizontal resolutions at the 10 meter level and vertical resolutions at the sub-meter level are possible.

  18. Fine Resolution Topographic Mapping of the Jovian Moons: A Ka-Band High Resolution Topographic Mapping Interferometric Synthetic Aperture Radar

    NASA Technical Reports Server (NTRS)

    Madsen, S. N.; Carsey, F. D.; Turtle, E. P.

    2003-01-01

    The topographic data set obtained by MOLA has provided an unprecedented level of information about Mars' geologic features. The proposed flight of JIMO provides an opportunity to accomplish a similar mapping of and comparable scientific discovery for the Jovian moons through use of an interferometric imaging radar analogous to the Shuttle radar that recently generated a new topographic map of Earth. A Ka-band single pass across-track synthetic aperture radar (SAR) interferometer can provide very high resolution surface elevation maps. The concept would use two antennas mounted at the ends of a deployable boom (similar to the Shuttle Radar Topographic Mapper) extended orthogonal to the direction of flight. Assuming an orbit altitude of approximately 100km and a ground velocity of approximately 1.5 km/sec, horizontal resolutions at the 10 meter level and vertical resolutions at the sub-meter level are possible.

  19. Mapping Boreal Wetlands Using Spaceborne Synthetic Aperture Radar

    NASA Astrophysics Data System (ADS)

    Podest, E.; McDonald, K. C.; Bohn, T.; Lettenmaier, D.

    2006-12-01

    Carbon and methane emissions from wetlands and lakes can have a large impact on global climate. These ecosystems are dominant features in the northern high latitudes hence the importance of assessing their spatial and temporal extent to improve upon global net carbon exchange estimates. Spaceborne synthetic aperture radar (SAR) is an effective tool for this purpose since large inaccessible areas can be monitored on a temporal basis regardless of atmospheric conditions or solar illumination and it is sensitive to vegetation and standing water. We employ ERS (C-band, 100 m, VV-polarization) and JERS (L-band, 100 m, HH-polarization) in this study to map wetlands within boreal sub-regions. Large scale L-band SAR mosaics assembled over boreal regions are used with supplementary multi-temporal data for the analysis. Path to path and year to year radiometric differences due predominantly to seasonal changes were a source of confusion. Decision tree classification tools are used to alleviate this problem. Digital elevation models (where available) and derived slope aspect are used to better distinguish drainage patterns. Texture images are used to help differentiate different wetland classes (e.g. fens, bogs, swamps, marshes, and open water). Examples of validated test regions are presented. This work was performed at the Jet Propulsion Laboratory, California Institute of Technology and the University of Washington under contract with the National Aeronautics and Space Administration.

  20. A comparison of infrared, radar, and geologic mapping of lunar craters

    USGS Publications Warehouse

    Thompson, T.W.; Masursky, H.; Shorthill, R.W.; Tyler, G.L.; Zisk, S.H.

    1974-01-01

    Between 1000 and 2000 infrared (eclipse) and radar anomalies have been mapped on the nearside hemisphere of the Moon. A study of 52 of these anomalies indicates that most are related to impact craters and that the nature of the infrared and radar responses is compatible with a previously developed geologic model of crater aging processes. The youngest craters are pronounced thermal and radar anomalies; that is, they have enhanced eclipse temperatures and are strong radar scatterers. With increasing crater age, the associated thermal and radar responses become progressively less noticeable until they assume values for the average lunar surface. The last type of anomaly to disappear is radar enhancement at longer wavelengths. A few craters, however, have infrared and radar behaviors not predicted by the aging model. One previously unknown feature - a field strewn with centimeter-sized rock fragments - has been identified by this technique of comparing maps at the infrared, radar, and visual wavelengths. ?? 1974 D. Reidel Publishing Company, Dordrecht-Holland.

  1. Use of radar image texture in geologic mapping

    NASA Technical Reports Server (NTRS)

    Farr, T. G.

    1983-01-01

    Large slope angle radar and small slope angle radar techniques are discussed. The techniques are developed to aid in the geologic interpretation of synthetic aperture radar (SAR) images. The application presented is for heavy vegetation and where very little other data can be obtained directly from remote sensing images. To understand the relationships between image texture, topography, lithology, geomorphology, and climate improves, textural information from SAR images are used for the identification of rock types to discriminate units. An active program is to integrate textural information from radar images directly with backscatter data from the same images, and with compositional information derived from visible near infrared sensors such as LANDSAT is explored. The role of quantitative textural information in this type of multisensor analysis which promises to be significant is outlined.

  2. 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.

  3. Global mapping strategies for a synthetic aperture radar system in orbit about Venus

    NASA Technical Reports Server (NTRS)

    Kerridge, S. J.

    1980-01-01

    An analysis of the global mapping of Venus using a synthetic aperture radar (SAR) is presented. The geometry of the side-looking radar, the narrow swath width, and the slow rotation of Venus combine to constrain the methods required to produce such a map within the primary mapping mission of 121.5 days. Parametric studies indicate that multiple strategies can satisfy the requirements of the mission with reasonable assumptions for the total recording capacity, the downlink data rate, and the operating time of the SAR on each revolution.

  4. Spotlight-Mode Synthetic Aperture Radar Processing for High-Resolution Lunar Mapping

    NASA Technical Reports Server (NTRS)

    Harcke, Leif; Weintraub, Lawrence; Yun, Sang-Ho; Dickinson, Richard; Gurrola, Eric; Hensley, Scott; Marechal, Nicholas

    2010-01-01

    During the 2008-2009 year, the Goldstone Solar System Radar was upgraded to support radar mapping of the lunar poles at 4 m resolution. The finer resolution of the new system and the accompanying migration through resolution cells called for spotlight, rather than delay-Doppler, imaging techniques. A new pre-processing system supports fast-time Doppler removal and motion compensation to a point. Two spotlight imaging techniques which compensate for phase errors due to i) out of focus-plane motion of the radar and ii) local topography, have been implemented and tested. One is based on the polar format algorithm followed by a unique autofocus technique, the other is a full bistatic time-domain backprojection technique. The processing system yields imagery of the specified resolution. Products enabled by this new system include topographic mapping through radar interferometry, and change detection techniques (amplitude and coherent change) for geolocation of the NASA LCROSS mission impact site.

  5. Pulse compression with very low sidelobes in an airborne rain mapping radar

    NASA Astrophysics Data System (ADS)

    Tanner, A.; Durden, S. L.; Denning, R.; Im, E.; Li, F. K.; Ricketts, W.; Wilson, W.

    1994-01-01

    Pulse compression allows a substantial reduction in the peak transmitted power of a radar and is attractive for spaceborne remote sensing applications. In the case of a downward looking rain measuring radar, however, the range sidelobes associated with surface return can mask return from rain and must be kept to a minimum. Here, we describe the pulse compression system for the NASA/JPL Airborne Rain Mapping Radar. This system uses time-domain weighting of the transmitted pulse and is able to achieve a range sidelobe level of -55 dB or better in flight tests. This is significantly lower than other values reported in the open literature.

  6. Damage Proxy Map from Interferometric Synthetic Aperture Radar Coherence

    NASA Technical Reports Server (NTRS)

    Yun, Sang-Ho (Inventor); Fielding, Eric Jameson (Inventor); Webb, Frank H. (Inventor); Simons, Mark (Inventor)

    2015-01-01

    A method, apparatus, and article of manufacture provide the ability to generate a damage proxy map. A master coherence map and a slave coherence map, for an area prior and subsequent to (including) a damage event are obtained. The slave coherence map is registered to the master coherence map. Pixel values of the slave coherence map are modified using histogram matching to provide a first histogram of the master coherence map that exactly matches a second histogram of the slave coherence map. A coherence difference between the slave coherence map and the master coherence map is computed to produce a damage proxy map. The damage proxy map is displayed with the coherence difference displayed in a visually distinguishable manner.

  7. Acceleration of Topographic Map Production Using Semi-Automatic DTM from Dsm Radar Data

    NASA Astrophysics Data System (ADS)

    Rizaldy, Aldino; Mayasari, Ratna

    2016-06-01

    Badan Informasi Geospasial (BIG) is government institution in Indonesia which is responsible to provide Topographic Map at several map scale. For medium map scale, e.g. 1:25.000 or 1:50.000, DSM from Radar data is very good solution since Radar is able to penetrate cloud that usually covering tropical area in Indonesia. DSM Radar is produced using Radargrammetry and Interferrometry technique. The conventional method of DTM production is using "stereo-mate", the stereo image created from DSM Radar and ORRI (Ortho Rectified Radar Image), and human operator will digitizing masspoint and breakline manually using digital stereoplotter workstation. This technique is accurate but very costly and time consuming, also needs large resource of human operator. Since DSMs are already generated, it is possible to filter DSM to DTM using several techniques. This paper will study the possibility of DSM to DTM filtering using technique that usually used in point cloud LIDAR filtering. Accuracy of this method will also be calculated using enough numbers of check points. If the accuracy meets the requirement, this method is very potential to accelerate the production of Topographic Map in Indonesia.

  8. Lunar Topographic Mapping Using a New High Resolution Mode for the GSSR Radar

    NASA Technical Reports Server (NTRS)

    Hensley, Scott; Gurrola, Eric; Slade, Martin; Quirk, Kevin; Srinivasan, Meera; Lee, Clement; Yun, Sang-Ho; Jao, Joseph; Wilson, Barbara; De Jong, Eric; Marechal, Nick; Weintraub, Lawrence; Dickinson, Richard; Bloom, Ronald; Karamyan, Grant; Lilje, Anneliese; Harcke, Leif

    2010-01-01

    Mapping the Moon's topography using Earth based radar interferometric measurements by the Goldstone Solar System Radar (GSSR) has been done several times since the mid 1990s. In 2008 we reported at this conference the generation of lunar topographic maps having approximately 4 m height accuracy at a horizontal posting of 40 m. Since then GSSR radar has been improved to allow 40 MHz bandwidth imaging and consequently obtained images and interferograms with a resolution of about 4 m in range by 5 m in azimuth. The long synthetic aperture times of approximately 90 minutes in duration necessitated a migration from range/Doppler image formation techniques to spotlight mode processing and autofocusing methods. The improved resolution imagery should permit the generation of topographic maps with a factor of two better spatial resolution with about same height accuracy. Coupled the with the recent availability of new lidar topography maps of the lunar surface made by orbiting satellites of Japan and the United States the geodetic control of the radar generated maps products can be improved dramatically. This paper will discuss the hardware and software improvements made to the GSSR and present some of the new high resolution products.

  9. Navigation errors encountered using weather-mapping radar for helicopter IFR guidance to oil rigs

    NASA Technical Reports Server (NTRS)

    Phillips, J. D.; Bull, J. S.; Hegarty, D. M.; Dugan, D. C.

    1980-01-01

    In 1978 a joint NASA-FAA helicopter flight test was conducted to examine the use of weather-mapping radar for IFR guidance during landing approaches to oil rig helipads. The following navigation errors were measured: total system error, radar-range error, radar-bearing error, and flight technical error. Three problem areas were identified: (1) operational problems leading to pilot blunders, (2) poor navigation to the downwind final approach point, and (3) pure homing on final approach. Analysis of these problem areas suggests improvement in the radar equipment, approach procedure, and pilot training, and gives valuable insight into the development of future navigation aids to serve the off-shore oil industry.

  10. Quantitative estimation of Tropical Rainfall Mapping Mission precipitation radar signals from ground-based polarimetric radar observations

    NASA Astrophysics Data System (ADS)

    Bolen, Steven M.; Chandrasekar, V.

    2003-06-01

    The Tropical Rainfall Mapping Mission (TRMM) is the first mission dedicated to measuring rainfall from space using radar. The precipitation radar (PR) is one of several instruments aboard the TRMM satellite that is operating in a nearly circular orbit with nominal altitude of 350 km, inclination of 35°, and period of 91.5 min. The PR is a single-frequency Ku-band instrument that is designed to yield information about the vertical storm structure so as to gain insight into the intensity and distribution of rainfall. Attenuation effects on PR measurements, however, can be significant and as high as 10-15 dB. This can seriously impair the accuracy of rain rate retrieval algorithms derived from PR signal returns. Quantitative estimation of PR attenuation is made along the PR beam via ground-based polarimetric observations to validate attenuation correction procedures used by the PR. The reflectivity (Zh) at horizontal polarization and specific differential phase (Kdp) are found along the beam from S-band ground radar measurements, and theoretical modeling is used to determine the expected specific attenuation (k) along the space-Earth path at Ku-band frequency from these measurements. A theoretical k-Kdp relationship is determined for rain when Kdp ≥ 0.5°/km, and a power law relationship, k = a Zhb, is determined for light rain and other types of hydrometers encountered along the path. After alignment and resolution volume matching is made between ground and PR measurements, the two-way path-integrated attenuation (PIA) is calculated along the PR propagation path by integrating the specific attenuation along the path. The PR reflectivity derived after removing the PIA is also compared against ground radar observations.

  11. Global digital topography mapping using a scanning radar altimeter

    NASA Technical Reports Server (NTRS)

    Elachi, C.; Im, K. E.; Li, F.; Rodriguez, E.

    1987-01-01

    The conceptual design of a Scanning Radar Altimeter system capable of collecting less than 300-m spatial and less than 3-m height resolution digital topography data for the entire globe, from an orbital platform, is presented. A 37-GHz frequency SRA system is used to achieve the requisite resolution while reducing antenna length in the along-track dimension. Near-global coverage in a short time period is obtained by scanning the antenna beam cross-track, in a swath of about 100 km. Attention is given to the algorithm that will be used to retrieve pixel height from the return waveform.

  12. F region ionosphere effects on the mapping accuracy of SuperDARN HF radar echoes

    NASA Astrophysics Data System (ADS)

    Chen, X.-C.; Lorentzen, D. A.; Moen, J. I.; Oksavik, K.; Baddeley, L. J.; Lester, M.

    2016-05-01

    Structured particle precipitation in the cusp is an important source for the generation of F region ionospheric irregularities. The equatorward boundaries of broad Doppler spectral width in Super Dual Auroral Radar Network (SuperDARN) data and the concurrent OI 630.0 nm auroral emission are good empirical proxies for the dayside open-closed field line boundary. However, SuperDARN currently employs a simple virtual model to determine the location of its echoes, instead of a direct calculation of the radio wave path. The varying ionospheric conditions could influence the final mapping accuracy of SuperDARN echoes. A statistical comparison of the offsets between the SuperDARN Finland radar spectral width boundary (SWB) and the OI 630.0 nm auroral emission boundary (AEB) from a meridian-scanning photometer (MSP) on Svalbard is performed in this paper. By restricting the location of the 630.0 nm data to be near local zenith where the MSP has the highest spatial resolution, the optical mapping errors were significantly reduced. The variation of the SWB-AEB offset confirms that there is a close relationship between the mapping accuracy of the HF radar echoes and solar activity. The asymmetric variation of the SWB-AEB offset versus magnetic local time suggests that the intake of high-density solar extreme ultraviolet ionized plasma from postnoon at subauroral latitudes could result in a stronger refraction of the HF radar signals in the noon sector, while changing the HF radar operating frequency also has a refraction effect that contributes to the final location of the HF radar echoes.

  13. F-region ionosphere effects on the mapping accuracy of SuperDARN HF radar echoes

    NASA Astrophysics Data System (ADS)

    Chen, Xiangcai; Lorentzen, Dag; Moen, Jøran; Oksavik, Kjellmar; Baddeley, Lisa; Lester, Mark

    2016-04-01

    Structured particle precipitation in the cusp is an important source for the generation of F -region ionospheric irregularities. The equatorward boundaries of broad Doppler spectral width in Super Dual Auroral Radar Network (SuperDARN) data and the concurrent OI 630.0 nm auroral emission are good empirical proxies for the dayside open-closed field line boundary (OCB). However, SuperDARN currently employs a simple virtual model to determine the location of its echoes, instead of a direct calculation of the radio wave path. The varying ionospheric conditions could influence the final mapping accuracy of SuperDARN echoes. A statistical comparison of the offsets between the SuperDARN Finland radar spectral width boundary (SWB) and the OI 630.0 nm auroral emission boundary (AEB) from a meridian-scanning photometer (MSP) in Longyearbyen from December 1995 to January 2014 in wintertime is performed. By restricting the location of the OI 630.0 nm data to be near local zenith, where the MSP has the highest spatial resolution, the mapping errors were significantly reduced for the AEB. The variation of the SWB - AEB offset confirms that there is a close relationship between the mapping accuracy of the HF radar echoes and solar activity. The asymmetric variation of the SWB - AEB offset versus magnetic local time suggests that the intake of high density solar extreme ultraviolet ionized plasma from post-noon at sub-auroral latitudes could result in a stronger refraction of the HF radar signals in the noon sector. The changing HF radar operating frequency also has a refraction effect that contributes to the final location of the HF radar echoes.

  14. Flood Frequency Mapping of the Middle Mahakam Lowland Area Using Satellite Radar

    NASA Astrophysics Data System (ADS)

    Hidayat, H.; Hoekman, D. H.; Vissers, M. A.; Hoitink, A.

    2011-12-01

    Floodplain lakes and peatlands in the middle Mahakam lowland area are considered as an ecologically important wetland in East Kalimantan, Indonesia. However, due to lack of data, the hydrologic functioning of the region is still poorly understood. Among remote sensing techniques that can increase data availability, radar is well-suitable for the identification, mapping, and measurement of tropical wetlands, for its cloud unimpeded sensing and night and day operation. Here we aim to extract flood extent and flood frequency information from a series of radar images of the middle Mahakam lowland area. We explore the use of Phased Array L-band Synthetic Aperture Radar (PALSAR) imagery for observing flood inundation dynamics by incorporating field water level measurements. Water level measurements were carried out along the river, in lakes and in peatland, using pressure transducers. Bathymetry measurements were carried out in the main lakes. A series of PALSAR images covering the middle and lower Mahakam area in the years 2007 and 2010 was collected. A land use/land cover map was available from a previous analysis of PALSAR imagery. To analyze Radar backscatter behavior for different land cover types, several regions of interest were selected, based on the land cover classes. Medium shrub and high shrub were among land cover classes found to be sensitive to flooding, whereas several other classes, including peat forest, riverine forest and tree plantation, featured only slight changes of radar backscatter with flood inundation. An analysis of the relationship between radar backscatter and water levels was carried out in each of the regions of interest. For lakes and shrub covered peatland, where the range of water level variation was high, a good water level-backscatter correlation was obtained. In peat forest covered peatland subject to a small range of water level variation, water level-backscatter correlations were poor. Spectral analysis of the vegetated floodplain

  15. Mobile Mapping by Fmcw Synthetic Aperture Radar Operating at 300 GHZ

    NASA Astrophysics Data System (ADS)

    Palm, S.; Sommer, R.; Hommes, A.; Pohl, N.; Stilla, U.

    2016-06-01

    While optical cameras or laser systems are widely used for mobile mapping low attention was payed for radar systems. Due to new semiconductor technologies, compact and leight weight SAR systems based on the Frequency Modulated Continuous Wave (FMCW) principle in the millimeter wave domain can serve for mobile radar mapping on cars. For mapping of long stripes along roads in close range a special strategy for focusing of SAR images was developed. Hereby local adapted planes for processing are used considering the IMU data of the sensor. An experimental system was designed for high resolution radar mapping of urban scenes in close range geometry. This small and leight weighted system has a bandwidth of 30 GHz (5 mm resolution) and operates with 300 GHz in the lower terahertz domain. Experiments with a van in an urban scenario were carried out for proof of applicability of an operating SAR system resolving objects in the subcentimeter domain. The results show that narrow cracks in the asphalt of the road are visible and the measuring of small metallic objects placed in the scene is possible. Based on this mobile mapping techniques a first result from an acquisition of vertical facade structure is shown.

  16. LANDSAT and radar mapping of intrusive rocks in SE-Brazil

    NASA Technical Reports Server (NTRS)

    Parada, N. D. J. (Principal Investigator); Dossantos, A. R.; Dosanjos, C. E.; Moreira, J. C.; Barbosa, M. P.; Veneziani, P.

    1982-01-01

    The feasibility of intrusive rock mapping was investigated and criteria for regional geological mapping established at the scale of 1:500,00 in polycyclic and polymetamorphic areas using the logic method of photointerpretation of LANDSAT imagery and radar from the RADAMBRASIL project. The spectral behavior of intrusive rocks, was evaluated using the interactive multispectral image analysis system (Image-100). The region of Campos (city) in northern Rio de Janeiro State was selected as the study area and digital imagery processing and pattern recognition techniques were applied. Various maps at the 2:250,000 scale were obtained to evaluate the results of automatic data processing.

  17. Using Radar Plots for Curricular Mapping to Visualize Assessment in a New Doctor of Pharmacy Program.

    PubMed

    Dintzner, Matthew R; Nemec, Eric C; Tanzer, Kim; Welch, Beth

    2015-10-25

    OBJECTIVE. To initiate mapping of the curriculum to the core competencies of our program and to develop a novel and visually accessible method for communicating data to all stakeholders. DESIGN. An online survey was developed to gauge the extent to which instructors and students perceive that courses within the curriculum and assess students' ability to achieve each of the 10 core competencies. Response data were collected and processed as radar plots in Microsoft Excel. ASSESSMENT. Response rate for faculty members was 100% and 86%for students. Radar plots provided images of the relative extent to which each course surveyed was perceived to contribute to core competencies. CONCLUSION. Using radar plots to present perception data is visually descriptive, makes patterns/trends readily apparent, and facilitates the development of an ongoing culture of assessment.

  18. Objectively mapping HF radar-derived surface current data using measured and idealized data covariance matrices

    NASA Astrophysics Data System (ADS)

    Kim, Sung Yong; Terrill, Eric; Cornuelle, Bruce

    2007-06-01

    Surface currents measured by high-frequency radars are objectively mapped using covariance matrices computed from hourly surface current vectors spanning two years. Since retrievals of surface radial velocities are inherently gappy in space and time, the irregular density of surface current data leads to negative eigenvalues in the sample covariance matrix. The number and the magnitude of the negative eigenvalues depend on the degree of data continuity used in the matrix computation. In a region of 90% data coverage, the negative eigenvalues of the sample covariance matrix are small enough to be removed by adding a noise term to the diagonal of the matrix. The mapping is extended to regions of poorer data coverage by applying a smoothed covariance matrix obtained by spatially averaging the sample covariance matrix. This approach estimates a stable covariance matrix of surface currents for regions with the intermittent radar coverage. An additional benefit is the removal of baseline errors that often exist between two radar sites. The covariance matrices and the correlation functions of the surface currents are exponential in space rather than Gaussian, as is often assumed in the objective mapping of oceanographic data sets. Patterns in the decorrelation length scale provide the variabilities of surface currents and the insights on the influence of topographic features (bathymetry and headlands). The objective mapping approach presented herein lends itself to various applications, including the Lagrangian transport estimates, dynamic analysis through divergence and vorticity of current vectors, and statistical models of surface currents.

  19. Operational Mapping of Soil Moisture Using Synthetic Aperture Radar Data: Application to the Touch Basin (France)

    PubMed Central

    Baghdadi, Nicolas; Aubert, Maelle; Cerdan, Olivier; Franchistéguy, Laurent; Viel, Christian; Martin, Eric; Zribi, Mehrez; Desprats, Jean François

    2007-01-01

    Soil moisture is a key parameter in different environmental applications, such as hydrology and natural risk assessment. In this paper, surface soil moisture mapping was carried out over a basin in France using satellite synthetic aperture radar (SAR) images acquired in 2006 and 2007 by C-band (5.3 GHz) sensors. The comparison between soil moisture estimated from SAR data and in situ measurements shows good agreement, with a mapping accuracy better than 3%. This result shows that the monitoring of soil moisture from SAR images is possible in operational phase. Moreover, moistures simulated by the operational Météo-France ISBA soil-vegetation-atmosphere transfer model in the SIM-Safran-ISBA-Modcou chain were compared to radar moisture estimates to validate its pertinence. The difference between ISBA simulations and radar estimates fluctuates between 0.4 and 10% (RMSE). The comparison between ISBA and gravimetric measurements of the 12 March 2007 shows a RMSE of about 6%. Generally, these results are very encouraging. Results show also that the soil moisture estimated from SAR images is not correlated with the textural units defined in the European Soil Geographical Database (SGDBE) at 1:1000000 scale. However, dependence was observed between texture maps and ISBA moisture. This dependence is induced by the use of the texture map as an input parameter in the ISBA model. Even if this parameter is very important for soil moisture estimations, radar results shown that the textural map scale at 1:1000000 is not appropriate to differentiate moistures zones.

  20. Method and apparatus for contour mapping using synthetic aperture radar

    NASA Technical Reports Server (NTRS)

    Goldstein, R. M.; Caro, E. R.; Wu, C. (Inventor)

    1985-01-01

    By using two SAR antennas spaced a known distance, B, and oriented at substantially the same look angle to illuminate the same target area, pixel data from the two antennas may be compared in phase to determine a difference delta phi from which a slant angle theta is determined for each pixel point from an equation Delta phi = (2 pi B/lambda)sin(theta - alpha), where lambda is the radar wavelength and alpha is the roll angle of the aircraft. The height, h, of each pixel point from the aircraft is determined from the equation h = R cos theta, and from the known altitude, a, of the aircraft above sea level, the altitude (elevation), a', of each point is determined from the difference a - h. This elevation data may be displayed with the SAR image by, for example, quantizing the elevation at increments of 100 feet starting at sea level, and color coding pixels of the same quantized elevation. The distance, d, of each pixel from the ground track of the aircraft used for the display may be determined more accurately from the equation d = R sin theta.

  1. Multipolarization radar images for geologic mapping and vegetation discrimination

    NASA Technical Reports Server (NTRS)

    Evans, D. L.; Farr, T. G.; Ford, J. P.; Thompson, T. W.; Werner, C. L.

    1986-01-01

    NASA has developed an airborne SAR that simultaneously yields image data in four linear polarizations in L-band with 10-m resolution over a swath of about 10 km. Signal data are recorded both optically and digitally and annotated in each of the channels to facilitate completely automated digital correlation. Comparison of the relative intensities of the different polarizations furnishes discriminatory mapping information. Local intensity variations in like-polarization images result from topographic effects, while strong cross polarization responses denote the effects of vegetation cover and, in some cases, possible scattering from the subsurface. In each of the areas studied, multiple polarization data led to the discrimination and mapping of unique surface unit features.

  2. Operational shoreline mapping with high spatial resolution radar and geographic processing

    USGS Publications Warehouse

    Rangoonwala, Amina; Jones, Cathleen E; Chi, Zhaohui; Ramsey III, Elijah W.

    2017-01-01

    A comprehensive mapping technology was developed utilizing standard image processing and available GIS procedures to automate shoreline identification and mapping from 2 m synthetic aperture radar (SAR) HH amplitude data. The development used four NASA Uninhabited Aerial Vehicle SAR (UAVSAR) data collections between summer 2009 and 2012 and a fall 2012 collection of wetlands dominantly fronted by vegetated shorelines along the Mississippi River Delta that are beset by severe storms, toxic releases, and relative sea-level rise. In comparison to shorelines interpreted from 0.3 m and 1 m orthophotography, the automated GIS 10 m alongshore sampling found SAR shoreline mapping accuracy to be ±2 m, well within the lower range of reported shoreline mapping accuracies. The high comparability was obtained even though water levels differed between the SAR and photography image pairs and included all shorelines regardless of complexity. The SAR mapping technology is highly repeatable and extendable to other SAR instruments with similar operational functionality.

  3. A signal processing view of strip-mapping synthetic aperture radar

    NASA Technical Reports Server (NTRS)

    Munson, David C., Jr.; Visentin, Robert L.

    1989-01-01

    The authors derive the fundamental strip-mapping SAR (synthetic aperture radar) imaging equations from first principles. They show that the resolution mechanism relies on the geometry of the imaging situation rather than on the Doppler effect. Both the airborne and spaceborne cases are considered. Range processing is discussed by presenting an analysis of pulse compression and formulating a mathematical model of the radar return signal. This formulation is used to obtain the airborne SAR model. The authors study the resolution mechanism and derive the signal processing relations needed to produce a high-resolution image. They introduce spotlight-mode SAR and briefly indicate how polar-format spotlight processing can be used in strip-mapping SAR. They discuss a number of current and future research directions in SAR imaging.

  4. Reliably Flattened Radar Backscatter For Wet Snow Mapping From Wide-Swath Sensors

    NASA Astrophysics Data System (ADS)

    Small, David; Miranda, Nuno; Ewen, Tracy; Jonas, Tobias

    2013-12-01

    Retrieval of wet snow extent with high temporal resolution over large areas that include topography requires use of wide swath SAR and radiometric terrain correction to enable backscatter comparisons across different orbital tracks. We report on springtime wet snow mapping using a time series of Envisat ASAR wide swath (WS) images covering the Swiss Alps. The ASAR observations were used to constrain a runoff model for a local catchment; performance was assessed with and without integration of the radar data. Our EOPI project began an unprecedentedly dense series of ASAR WS acquisitions over Switzerland in March 2012. Wet snow maps at the national scale were generated and integrated for the first time on an operational basis within the Swiss Institute for Snow and Avalanche Research SLF. Lessons learned from this initial operational integration test are discussed, with a view toward the monitoring possibilities coming soon with the Sentinel-1 radar satellites.

  5. A Fine-Resolution Radar for Mapping Near-Surface Isochronous Layers

    NASA Astrophysics Data System (ADS)

    Rink, T. P.; Kanagaratnam, P.; Braaten, D.; Zimmerman, K.; Akins, T.; Gogineni, S.

    2005-12-01

    Information on the spatial and temporal variation of snow accumulation is required for interpreting satellite-based radar and laser surface elevation measurements made by CryoSAT and ICESAT altimeters. Current methods of using ice cores and analyzing snow pit stratigraphy is time consuming and prone to errors in spatial representation due to the sparse sampling. Remote sensing methods that can map near-surface internal layers for estimating spatial and temporal variation are required. To accomplish this, we developed a 12-18 GHz FMCW radar to map near-surface layers with 3 cm vertical resolution to a depth of about 10 m. We developed the system to be mobile and self-contained so that spatial variability of the accumulation over a large area can be characterized. The fine resolution of this radar is achieved by its wide bandwidth and by illuminating the target area with a plane-wave, which is implemented using an offset-fed parabolic reflector. Traditional wide-beamwidth antennas are susceptible to spherical wave scattering from off-vertical targets that can potentially mask weaker reflections from internal layers. The radar features a fast transmit waveform synthesizer implemented using a voltage controlled oscillator (VCO) and a phase-locked loop (PLL) using a linear chirp as the reference. The highly linear reference chirp was generated by a direct digital synthesis (DDS) waveform generator and compared against the instantaneous output of the VCO to create a highly linear 12 to 18 GHz transmit chirp. The waveform synthesizer can be swept from 12 to 18 GHz in 500 microseconds. The antenna was mounted on a sled and the radar system was integrated with the antenna feed. We designed and built the sled with a gimbaled antenna mount and sensing control system to ensure that the antenna points at nadir. The radar system was successfully tested at the Summit camp, Greenland, in July 2005. We collected a large amount of data from various locations around Summit camp. The

  6. A study of an orbital radar mapping mission to Venus. Volume 2: Configuration comparisons and systems evaluation

    NASA Technical Reports Server (NTRS)

    1973-01-01

    Configuration comparisons and systems evaluation for the orbital radar mapping mission of the planet Venus are discussed. Designs are recommended which best satisfy the science objectives of the Venus radar mapping concept. Attention is given to the interaction and integration of those specific mission-systems recommendations with one another, and the final proposed designs are presented. The feasibility, cost, and scheduling of these configurations are evaluated against assumptions of reasonable state-of-the-art growth and space funding expectations.

  7. A study of an orbital radar mapping mission to Venus. Volume 3: Parametric studies and subsystem comparisons

    NASA Technical Reports Server (NTRS)

    1973-01-01

    Parametric studies and subsystem comparisons for the orbital radar mapping mission to planet Venus are presented. Launch vehicle requirements and primary orbiter propulsion system requirements are evaluated. The systems parametric analysis indicated that orbit size and orientation interrelated with almost all of the principal spacecraft systems and influenced significantly the definition of orbit insertion propulsion requirements, weight in orbit capability, radar system design, and mapping strategy.

  8. Radar Backscatter and Coherence Information Supporting High Quality Urban Mapping

    NASA Astrophysics Data System (ADS)

    Fischer, P.; Perski, Z.; Wannemacher, S.

    2004-06-01

    The potential of a synergetic use of different data sources for a high quality mapping of urban features is described in this paper. In the urban application domain, beside the different EO-sensors and products there are a lot of high resolution and high quality GIS- and digital map databases available (e.g. ATKIS in Germany), provided by public authorities but also by private industry. Fusing this ground-based data with remotely sensed information is resulting in high quality thematic datasets. Using ATKIS Geodata, IKONOS multispectral- and ERS-SAR / ENVISAT-ASAR data as input, in the research described we implemented a GIS-based expert system to derive in a first step the degree of sealing in the regions of interest (ROI). Joining the reclassified ATKIS-data with a vegetation index, the backscatter- and the coherence information, the output of the processing chain is a vector data layer dividing the ROI in different classes of sealing. Adding the SAR-/ASAR derived backscatter and coherence data into the spatial analysis results in a partial improvement of the classification process, especially in rural areas.

  9. Radar-Assisted Mapping of Massive Ice in Western Utopia Planitia, Mars: Degradational Mechanisms and Implications for Surface Evolution

    NASA Astrophysics Data System (ADS)

    Stuurman, C. M.; Levy, J. S.; Holt, J. W.; Harrison, T. N.; Osinski, G. R.

    2015-12-01

    Western Utopia Planitia remains an enigmatic region of Mars. Radar and morphological analyses have framed the area as rich in ground ice, however there exist multiple theories regarding how the ice was emplaced. Here, we combine radar and morphological analyses to characterize the recent history of water ice in western Utopia Planitia. A radar reflective interface found in SHAllow RADar (SHARAD) data in Utopia Planitia is found to correlate with layered mesas 80-110 m thick. Discontinuities in the radar reflective interface relate to degradation of the layered mesas. This work uses the extent of the reflective interface to map the previous extent of the layered mesas, which we believe constitutes the remnants of a large ice sheet formed in the Late Amazonian. The past volume of the ice sheet is to be determined by the SHARAD-assisted mapping. This volume will be related to the recent climate history of western Utopia Planitia.

  10. A scanning radar altimeter for mapping continental topography

    NASA Technical Reports Server (NTRS)

    Dixon, T. H.

    1986-01-01

    Topographic information constitutes a fundamental data set for the Earth sciences. In the geological and geophysical sciences, topography combined with gravitational information provides an important constraint on the structure and rheologic properties of the crust and lithosphere. Detailed topography data can also be used to map offsets associated with faulting and to reveal the effects of tectonic deformation. In the polar regions, elevation data form a crucial but as yet largely unavailable resource for studying ice sheet mass balance and ice flow dynamics. The vast Antarctic ice sheet is the largest fresh water reservoir on Earth and is an important influence on ocean circulation and global climate. However, our knowledge of its stability is so limited that we cannot even specify whether the Antarctic ice sheet is growing or shrinking. It is clear that there is need for high quality global topography data. A summary of potential applications with their resolution requirements is shown.

  11. Radar Characteristics of Vesta's Polar Regions using Visible and Infrared Mapping Spectrometer and Bistatic Radar Observations by the Dawn Mission

    NASA Astrophysics Data System (ADS)

    Palmer, E. M.; Heggy, E.; Kofman, W. W.; Russell, C. T.; Capria, M. T.; Tosi, F.

    2013-12-01

    Understanding surface roughness and potential volatile distribution on Vesta is crucial to constructing the evolution and the shock history of this unique protoplanet. Bistatic radar (BSR) observations using the Dawn communications antenna and the Goldstone 70-m antenna provide a unique opportunity to explore the parametric space associated with the surface's radar properties, which are affected by variation in surface roughness and the presence of volatiles. In order to assess the surface's dielectric properties, we first use observations by Dawn's Visible and Infrared mapping spectrometer (VIR) to constrain the upper regolith's bulk composition, surface density, and diurnal surface temperature variation. These determine the surface dielectric constant that can later be used to explore potential ice enrichment and porosity and also to constrain surface roughness. Based on the studies of Cartwright et al. (2013), we identify basaltic lunar regolith as a first-order analog to Vesta's regolith since both are desiccated and brecciated with significant basaltic components and their regoliths both undergo gardening by meteoritic impacts--generating a comparable grain size distribution and density profile in the upper regolith. We therefore use basaltic lunar dust as a first-order analog in the investigation of the dielectric and thermal properties of Vesta's surface material. We then use observations by VIR to measure surface temperatures at times near local solar noon, and derive surface densities from thermal modeling of heat transfer in the upper regolith. With surface density and modeled night and day temperatures, we then use the laboratory-measured dielectric dependence of basaltic lunar dust on density and temperature to construct a global model of dielectric constants over the surface of Vesta for a given time in its rotation. Our results suggest that at the 50 km/pixel resolution of our global surface temperature model, surface density is relatively constant at

  12. Flight investigation of helicopter IFR approaches to oil rigs using airborne weather and mapping radar

    NASA Technical Reports Server (NTRS)

    Bull, J. S.; Hegarty, D. M.; Phillips, J. D.; Sturgeon, W. R.; Hunting, A. W.; Pate, D. P.

    1979-01-01

    Airborne weather and mapping radar is a near-term, economical method of providing 'self-contained' navigation information for approaches to offshore oil rigs and its use has been rapidly expanding in recent years. A joint NASA/FAA flight test investigation of helicopter IFR approaches to offshore oil rigs in the Gulf of Mexico was initiated in June 1978 and conducted under contract to Air Logistics. Approximately 120 approaches were flown in a Bell 212 helicopter by 15 operational pilots during the months of August and September 1978. The purpose of the tests was to collect data to (1) support development of advanced radar flight director concepts by NASA and (2) aid the establishment of Terminal Instrument Procedures (TERPS) criteria by the FAA. The flight test objectives were to develop airborne radar approach procedures, measure tracking errors, determine accpetable weather minimums, and determine pilot acceptability. Data obtained will contribute significantly to improved helicopter airborne radar approach capability and to the support of exploration, development, and utilization of the Nation's offshore oil supplies.

  13. Airborne and spaceborne radar images for geologic and environmental mapping in the Amazon rain forest, Brazil

    NASA Technical Reports Server (NTRS)

    Ford, John P.; Hurtak, James J.

    1986-01-01

    Spaceborne and airborne radar image of portions of the Middle and Upper Amazon basin in the state of Amazonas and the Territory of Roraima are compared for purposes of geological and environmental mapping. The contrasted illumination geometries and imaging parameters are related to terrain slope and surface roughness characteristics for corresponding areas that were covered by each of the radar imaging systems. Landforms range from deeply dissected mountain and plateau with relief up to 500 m in Roraima, revealing ancient layered rocks through folded residual mountains to deeply beveled pediplain in Amazonas. Geomorphic features provide distinct textural signatures that are characteristic of different rock associations. The principle drainages in the areas covered are the Rio Negro, Rio Branco, and the Rio Japura. Shadowing effects and low radar sensitivity to subtle linear fractures that are aligned parallel or nearly parallel to the direction of radar illumination illustrate the need to obtain multiple coverage with viewing directions about 90 degrees. Perception of standing water and alluvial forest in floodplains varies with incident angle and with season. Multitemporal data sets acquired over periods of years provide an ideal method of monitoring environmental changes.

  14. Flood mapping by combining the strengths of optical and Sentinel active radar remote sensing

    NASA Astrophysics Data System (ADS)

    Winsemius, H. C.; Brakenridge, G. R.; Westerhoff, R.; Huizinga, J.; Villars, N.; Bishop, C.

    2012-04-01

    Flood mapping with remote sensing plays an important role in large scale disaster management procedures. For this purpose, the Dartmouth Flood Observatory (DFO) gained experience since 1993 with the production of flood maps from optical satellite imagery and has currently established, together with NASA collaborators, a fully automated, global, near real-time service. Another consortium is also presently working on an automated, near real-time, global flood mapping procedure called the 'Global Flood Observatory' (GFO), which will make use of high resolution Sentinel data. The procedure is currently tested on Envisat active radar (ASAR) imagery. Both the DFO and GFO projects provide open data output of their data and maps. The optical and radar approaches to flood mapping each have advantages and suffer from shortcomings. Optical remote sensing via the U.S. MODIS and VIIRS sensors is constrained by cloud cover but can attain a high revisit frequency (>2 /day), whereas the Envisat ASAR is not affected by cloud cover, but uses a lower revisit frequency (generally once/3 days, depending on the location). In this contribution, we demonstrate the combination of both approaches into one flood mapping result. This results in improved flood mapping in a case study over the Chao Phraya basin (Bangkok surroundings) during the recent October-November 2011 extreme flooding. The combined map shows that during overpass, ASAR reveals flooded regions over cloud-obscured areas, which clearly follow elevated features in the landscape such as roads, embankments and railways. Meanwhile, the high frequency of delivery of the optical information ensures timely information. Also, the quite different water classification methods used for the optical and ASAR data sources show good agreement and have been successfully merged into one GIS data product. This can also be automatically generated and disseminated on a global basis.

  15. Construction of Polarimetric Radar-Based Reference Rain Maps for the Iowa Flood Studies Campaign

    NASA Technical Reports Server (NTRS)

    Petersen, Walter; Wolff, David; Krajewski, Witek; Gatlin, Patrick

    2015-01-01

    The Global Precipitation Measurement (GPM) Mission Iowa Flood Studies (IFloodS) campaign was conducted in central and northeastern Iowa during the months of April-June, 2013. Specific science objectives for IFloodS included quantification of uncertainties in satellite and ground-based estimates of precipitation, 4-D characterization of precipitation physical processes and associated parameters (e.g., size distributions, water contents, types, structure etc.), assessment of the impact of precipitation estimation uncertainty and physical processes on hydrologic predictive skill, and refinement of field observations and data analysis approaches as they pertain to future GPM integrated hydrologic validation and related field studies. In addition to field campaign archival of raw and processed satellite data (including precipitation products), key ground-based platforms such as the NASA NPOL S-band and D3R Ka/Ku-band dual-polarimetric radars, University of Iowa X-band dual-polarimetric radars, a large network of paired rain gauge platforms, and a large network of 2D Video and Parsivel disdrometers were deployed. In something of a canonical approach, the radar (NPOL in particular), gauge and disdrometer observational assets were deployed to create a consistent high-quality distributed (time and space sampling) radar-based ground "reference" rainfall dataset, with known uncertainties, that could be used for assessing the satellite-based precipitation products at a range of space/time scales. Subsequently, the impact of uncertainties in the satellite products could be evaluated relative to the ground-benchmark in coupled weather, land-surface and distributed hydrologic modeling frameworks as related to flood prediction. Relative to establishing the ground-based "benchmark", numerous avenues were pursued in the making and verification of IFloodS "reference" dual-polarimetric radar-based rain maps, and this study documents the process and results as they pertain specifically

  16. Construction of Polarimetric Radar-Based Reference Rain Maps for the Iowa Flood Studies Campaign

    NASA Astrophysics Data System (ADS)

    Petersen, Walt; Krajewski, Witek; Wolff, David; Gatlin, Patrick

    2015-04-01

    The Global Precipitation Measurement (GPM) Mission Iowa Flood Studies (IFloodS) campaign was conducted in central and northeastern Iowa during the months of April-June, 2013. Specific science objectives for IFloodS included quantification of uncertainties in satellite and ground-based estimates of precipitation, 4-D characterization of precipitation physical processes and associated parameters (e.g., size distributions, water contents, types, structure etc.), assessment of the impact of precipitation estimation uncertainty and physical processes on hydrologic predictive skill, and refinement of field observations and data analysis approaches as they pertain to future GPM integrated hydrologic validation and related field studies. In addition to field campaign archival of raw and processed satellite data (including precipitation products), key ground-based platforms such as the NASA NPOL S-band and D3R Ka/Ku-band dual-polarimetric radars, University of Iowa X-band dual-polarimetric radars, a large network of paired rain gauge platforms, and a large network of 2D Video and Parsivel disdrometers were deployed. In something of a canonical approach, the radar (NPOL in particular), gauge and disdrometer observational assets were deployed to create a consistent high-quality distributed (time and space sampling) radar-based ground "reference" rainfall dataset, with known uncertainties, that could be used for assessing the satellite-based precipitation products at a range of space/time scales. Subsequently, the impact of uncertainties in the satellite products could be evaluated relative to the ground-benchmark in coupled weather, land-surface and distributed hydrologic modeling frameworks as related to flood prediction. Relative to establishing the ground-based "benchmark", numerous avenues were pursued in the making and verification of IFloodS "reference" dual-polarimetric radar-based rain maps, and this study documents the process and results as they pertain specifically

  17. On the potential of long wavelength imaging radars for mapping vegetation types and woody biomass in tropical rain forests

    NASA Technical Reports Server (NTRS)

    Rignot, Eric J.; Zimmermann, Reiner; Oren, Ram

    1995-01-01

    In the tropical rain forests of Manu, in Peru, where forest biomass ranges from 4 kg/sq m in young forest succession up to 100 kg/sq m in old, undisturbed floodplain stands, the P-band polarimetric radar data gathered in June of 1993 by the AIRSAR (Airborne Synthetic Aperture Radar) instrument separate most major vegetation formations and also perform better than expected in estimating woody biomass. The worldwide need for large scale, updated biomass estimates, achieved with a uniformly applied method, as well as reliable maps of land cover, justifies a more in-depth exploration of long wavelength imaging radar applications for tropical forests inventories.

  18. Wide area coverage radar imaging satellite for earth applications. [surveillance and mapping of ice on Great Lakes

    NASA Technical Reports Server (NTRS)

    Stevens, G. H.; Ramler, J. R.

    1974-01-01

    A preliminary study was made of a radar imaging satellite for earth applications. A side-looking synthetic-aperture radar was considered and the feasibility of obtaining a wide area coverage to reduce the time required to image a given area was investigated. Two basic approaches were examined; low altitude sun-synchronous orbits using a multibeam/multifrequency radar system and equatorial orbits up to near-synchronous altitude using a single beam system. Surveillance and mapping of ice on the Great Lakes was used as a typical application to focus the study effort.

  19. Subsurface Feature Mapping of Mars using a High Resolution Ground Penetrating Radar System

    NASA Astrophysics Data System (ADS)

    Wu, T. S.; Persaud, D. M.; Preudhomme, M. A.; Jurg, M.; Smith, M. K.; Buckley, H.; Tarnas, J.; Chalumeau, C.; Lombard-Poirot, N.; Mann, B.

    2015-12-01

    As the closest Earth-like, potentially life-sustaining planet in the solar system, Mars' future of human exploration is more a question of timing than possibility. The Martian surface remains hostile, but its subsurface geology holds promise for present or ancient astrobiology and future habitation, specifically lava tube (pyroduct) systems, whose presence has been confirmed by HiRISE imagery.The location and characterization of these systems could provide a basis for understanding the evolution of the red planet and long-term shelters for future manned missions on Mars. To detect and analyze the subsurface geology of terrestrial bodies from orbit, a novel compact (smallsat-scale) and cost-effective approach called the High-resolution Orbiter for Mapping gEology by Radar (HOMER) has been proposed. Adapting interferometry techniques with synthetic aperture radar (SAR) to a ground penetrating radar system, a small satellite constellation is able to achieve a theoretical resolution of 50m from low-Mars orbit (LMO). Alongside this initial prototype design of HOMER, proposed data processing methodology and software and a Mars mission design are presented. This project was developed as part of the 2015 NASA Ames Academy for Space Exploration.

  20. Mapping of a major paleodrainage system in eastern Libya using orbital imaging radar: The Kufrah River

    NASA Astrophysics Data System (ADS)

    Paillou, Philippe; Schuster, Mathieu; Tooth, Stephen; Farr, Tom; Rosenqvist, Ake; Lopez, Sylvia; Malezieux, Jean-Marie

    2009-01-01

    Over the last few decades, remote sensing has revealed buried river channels in a number of regions worldwide, in many cases providing evidence of dramatic paleoenvironmental changes over Cenozoic time scales. Using orbital radar satellite imagery, we mapped a major paleodrainage system in eastern Libya, that could have linked the Kufrah Basin to the Mediterranean coast through the Sirt Basin, possibly as far back as the middle Miocene. Synthetic Aperture Radar images from the PALSAR sensor clearly reveal a 900 km-long river system, which starts with three main tributaries (north-eastern Tibesti, northern Uweinat and western Gilf Kebir/Abu Ras) that connect in the Kufrah oasis region. The river system then flows north through the Jebel Dalmah, and forms a large alluvial fan in the Sarir Dalmah. The sand dunes of the Calanscio Sand Sea prevent deep orbital radar penetration and preclude detailed reconstruction of any possible connection to the Mediterranean Sea, but a 300 km-long link to the Gulf of Sirt through the Wadi Sahabi paleochannel is likely. If this connection is confirmed, and its Miocene antiquity is established, then the Kufrah River, comparable in length to the Egyptian Nile, will have important implications for the understanding of the past environments and climates of northern Africa from the middle Miocene to the Holocene.

  1. Middle Atmosphere Program. Handbook for MAP. Volume 30: International School on Atmospheric Radar

    NASA Technical Reports Server (NTRS)

    Fukao, Shoichiro (Editor)

    1989-01-01

    Broad, tutorial coverage is given to the technical and scientific aspects of mesosphere stratosphere troposphere (MST) meteorological radar systems. Control issues, signal processing, atmospheric waves, the historical aspects of radar atmospheric dynamics, incoherent scatter radars, radar echoes, radar targets, and gravity waves are among the topics covered.

  2. A Novel Approach to Mapping Intertidal Areas Using Shore-Based X-band Marine Radar

    NASA Astrophysics Data System (ADS)

    Bird, Cai; Bell, Paul

    2014-05-01

    Monitoring the morphology of coastal zones in response to high energy weather events and changing patterns of erosion and deposition over time is vital in enabling effective decision-making at the coast. Common methods of mapping intertidal bathymetry currently include vessel-based sonar and airborne LiDAR surveys, which are expensive and thus not routinely collected on a continuous basis. Marine radar is a ubiquitous technology in the marine industry and many ports operate a system to guide ships into port, this work aims to utilise this already existing infrastructure to determine bathymetry over large intertidal areas, currently up to 4 km from the radar. Standard X-band navigational radar has been used in the marine industry to measure hydrodynamics and derive bathymetry using empirical techniques for several decades. Methods of depth mapping thus far have relied on the electromagnetic backscattering from wind-roughened water surface, which allows a radar to gather sea surface image data but requires the waves to be clearly defined. The work presented here does not rely on identifying and measuring these spatial wave features, which increases the robustness of the method. Image data collected by a 9.4Ghz Kelvin Hughes radar from a weather station on Hilbre Island at the mouth of the River Dee estuary, UK were used in the development of this method. Image intensity at each pixel is a function of returned electromagnetic energy, which in turn can be related to the roughness of the sea surface. Images collected over time periods of 30 minutes show general patterns of wave breaking and mark the advance and retreat of the waterline in accordance with the tidal cycle and intertidal morphology. Each pixel value can be extracted from these mean images and analysed over the course of several days, giving a fluctuating time series of pixel intensity, the gradient of which gives a series of pulses representing transitions between wet and dry at each location. A tidal

  3. Large Scale Mapping of Disturbance and Recovery Using Fusion of Radar and Lidar: An Assessment

    NASA Astrophysics Data System (ADS)

    Dubayah, R.; Saatchi, S. S.; Blair, J. B.; Shugart, H. H.; Hofton, M.

    2004-12-01

    Forested landscapes are generally composed of a heterogeneous mixture of patches that reflect the complex interaction of processes occurring at many spatial and temporal scales. Whether caused by natural disturbances, such as blow downs and fire, or management practices, such as logging and agriculture, ecosystem structure and carbon fluxes will vary strongly as a result of differences in successional stage. Identifying and tracking these dynamics through space and time has been extraordinarily difficult, given the burden and limited scope of field-based methods, and the limited efficacy of most remote sensing approaches. Lidar remote sensing has proven to be exceptionally effective for mapping forest structure and successional status, providing critical initialization for carbon modeling approaches. However, application of lidar-based methods has been hindered by the relative expense and sparse spatial coverage of existing data sets. Regional and continental scale studies may thus require the integration of sparse lidar observations with data from sensors that may reasonably be expected to provide continuous coverage of some aspect of forest structure at high spatial resolution over large areas. One such technology is radar remote sensing. In this paper we assess the potential of integrating p-band radar with waveform lidar for the mapping of disturbance and recovery. Lidar data acquired over the tropical forests of La Selva, Costa Rica, are used to derive canopy height, biomass, and forest vertical structure. These data are then combined with p-band radar acquired several years later to develop and evaluate approaches to fusion that facilitate the determination of ecosystem dynamics.

  4. Synthetic aperture radar and natural disasters: Hazard mapping using full polarimetry

    NASA Astrophysics Data System (ADS)

    Czuchlewski, Kristina Rodriguez

    This thesis focuses on developing algorithms for radar-based natural disaster response. We demonstrate that fully-polarimetric Synthetic Aperture Radar (SAR) can be used to assess natural disasters involving terrain resurfacing such as landslides, volcanic eruptions and fires. These hazards often temporarily remove a natural vegetation cover and, in doing so, modify the physical properties of the land surface. This land-cover disturbance causes a detectable change in dominant microwave scattering mechanism for the areas affected. SAR has operational advantages over optical sensors for rapid disaster assessment because of its day/night acquisition capability; its ability to "see through" smoke, clouds and dust; and its side-looking viewing geometry, which is an advantage whenever data collection directly above the site would prove dangerous. To assess the usefulness of fully-polarimetric SAR, we apply a uniform approach to map (1) landslides resulting from the 1999 Mw 7.6 Chi-Chi earthquake in Taiwan, (2) volcanic flows from the major 1996 eruption of Manam Volcano in Papua New Guinea, and (3) the extent of damage from the summer 2002 Rodeo-Chediski wildfire in Arizona, USA. We then reexamine the data from Manam Island and Taiwan to determine the effects of a polarization preserving speckle reduction filter. Our results demonstrate the potential utility of fully polarimetric SAR for hazard mapping and disaster response.

  5. Preliminary comparisons of VHF radar maps of F-region irregularities with scintillations in the equatorial region

    NASA Technical Reports Server (NTRS)

    Basu, S.; Aarons, J.; Mcclure, J. P.; Lahoz, C.; Bushby, A.; Woodman, R. F.

    1977-01-01

    Multiantenna 50 MHz radar backscatter maps of echo power from night-time F-region equatiorial irregularities obtained at Jicamarca, Peru were compared with simultaneous VHF scintillation observations from Huancayo at 137 and 254 MHz during the period 20 November to 12 December 1975. Saturation of VHF scintillations in excess of 20 dB was observed at both these frequencies during times when radar maps showed large intense plume structures rising into the topside ionosphere. On nights when only thin layers of bottomside irregularities were observed, moderate to weak scintillations were recorded at VHF. Preliminary values of east-west horizontal irregularity drift velocities were obtained and compared with scintillation rate observations. Using the 1.5-deg and 4.5-deg longitudinal separation between the Jicamarca radar and ionospheric observation points of the two satellites from Huancayo, information was derived regarding large-scale east-west structure during the development phase of the irregularities.

  6. Mapping surface currents from HF radar radial velocity measurements using optimal interpolation

    NASA Astrophysics Data System (ADS)

    Kim, Sung Yong; Terrill, Eric J.; Cornuelle, Bruce D.

    2008-10-01

    An optimal interpolation (OI) method to compute surface vector current fields from radial velocity measurements derived from high-frequency (HF) radars is presented. The method assumes a smooth spatial covariance relationship between neighboring vector currents, in contrast to the more commonly used un-weighted least-squares fitting (UWLS) method, which assumes a constant vector velocity within a defined search radius. This OI method can directly compute any quantities linearly related to the radial velocities, such as vector currents and dynamic quantities (divergence and vorticity) as well as the uncertainties of those respective fields. The OI method is found to be more stable than the UWLS method and reduces spurious vector solutions near the baselines between HF radar installations. The OI method produces a covariance of the uncertainty of the estimated vector current fields. Three nondimensional uncertainty indices are introduced to characterize the uncertainty of the vector current at a point, representing an ellipse with directional characteristics. The vector current estimation using the OI method eliminates the need for multiple mapping steps and optimally fills intermittent coverage gaps. The effects of angular interpolation of radial velocities, a commonly used step in the preprocessing of radial velocity data prior to vector current computation in the UWLS method, are presented.

  7. Advantages to Geoscience and Disaster Response from QuakeSim Implementation of Interferometric Radar Maps in a GIS Database System

    NASA Astrophysics Data System (ADS)

    Parker, Jay; Donnellan, Andrea; Glasscoe, Margaret; Fox, Geoffrey; Wang, Jun; Pierce, Marlon; Ma, Yu

    2015-08-01

    High-resolution maps of earth surface deformation are available in public archives for scientific interpretation, but are primarily available as bulky downloads on the internet. The NASA uninhabited aerial vehicle synthetic aperture radar (UAVSAR) archive of airborne radar interferograms delivers very high resolution images (approximately seven meter pixels) making remote handling of the files that much more pressing. Data exploration requiring data selection and exploratory analysis has been tedious. QuakeSim has implemented an archive of UAVSAR data in a web service and browser system based on GeoServer (http://geoserver.org). This supports a variety of services that supply consistent maps, raster image data and geographic information systems (GIS) objects including standard earthquake faults. Browsing the database is supported by initially displaying GIS-referenced thumbnail images of the radar displacement maps. Access is also provided to image metadata and links for full file downloads. One of the most widely used features is the QuakeSim line-of-sight profile tool, which calculates the radar-observed displacement (from an unwrapped interferogram product) along a line specified through a web browser. Displacement values along a profile are updated to a plot on the screen as the user interactively redefines the endpoints of the line and the sampling density. The profile and also a plot of the ground height are available as CSV (text) files for further examination, without any need to download the full radar file. Additional tools allow the user to select a polygon overlapping the radar displacement image, specify a downsampling rate and extract a modest sized grid of observations for display or for inversion, for example, the QuakeSim simplex inversion tool which estimates a consistent fault geometry and slip model.

  8. Effect of spatial resolution of radar-based inundation maps on the calibration of a spatial inundation model

    NASA Astrophysics Data System (ADS)

    Gobeyn, Sacha; Vernieuwe, Hilde; De Baets, Bernard; Bates, Paul; Verhoest Niko E., C.

    2013-04-01

    With advances in both flood mapping with satellite radar and computational science, the use of real-time spatial flood data holds the potential to support decision making during flood events. With recent improvements in satellite radar technology, current and future radar images are/will be delivered with higher spatial resolution. It is expected that these higher resolutions should improve the accuracy of the calibration and the prediction through data assimilation as more detailed information is available. However, these finer resolution data will result in an increased computational cost. Still, radar data of coarser resolution will remain available, and the question may then arise whether the calibration of a 2D-hydraulic model is significantly influenced by the resolution of the remotely-sensed inundation map. In order to answer this question, the raster-based inundation model, LISFLOOD-FP (Bates et al., 2000) is calibrated using a high resolution synthetic aperture radar image (ERS-2 SAR) of a flood event of the river Dee, Wales, in December 2006. Different radar resolutions are simulated through coarsening this image to different resolutions and retrieving the flood extent maps for the different resolutions. These flood maps are then used for calibrating the hydraulic model using the generalized likelihood uncertainty estimation (GLUE) framework presented by Aronica et al. (2002) as well as alternative calibration methods (e.g. Particle Swarm Optimization, PSO) to assess the possible impact of spatial resolution of the observed flood extent on the floodplain and channel Manning coefficient. Furthermore, the sensitivity of the calibration surface to error sources in radar measurement is evaluated by applying different magnitudes of noise to the radar image. References Aronica, G., Bates, P. D. and Horritt, M. S. (2002). Assessing the uncertainty in distributed model predictions using observed binary pattern information within GLUE. Hydrological Processes, 16

  9. Using rainfall radar data to improve interpolated maps of dose rate in the Netherlands.

    PubMed

    Hiemstra, Paul H; Pebesma, Edzer J; Heuvelink, Gerard B M; Twenhöfel, Chris J W

    2010-12-01

    The radiation monitoring network in the Netherlands is designed to detect and track increased radiation levels, dose rate more specifically, in 10-minute intervals. The network consists of 153 monitoring stations. Washout of radon progeny by rainfall is the most important cause of natural variations in dose rate. The increase in dose rate at a given time is a function of the amount of progeny decaying, which in turn is a balance between deposition of progeny by rainfall and radioactive decay. The increase in progeny is closely related to average rainfall intensity over the last 2.5h. We included decay of progeny by using weighted averaged rainfall intensity, where the weight decreases back in time. The decrease in weight is related to the half-life of radon progeny. In this paper we show for a rainstorm on the 20th of July 2007 that weighted averaged rainfall intensity estimated from rainfall radar images, collected every 5min, performs much better as a predictor of increases in dose rate than using the non-averaged rainfall intensity. In addition, we show through cross-validation that including weighted averaged rainfall intensity in an interpolated map using universal kriging (UK) does not necessarily lead to a more accurate map. This might be attributed to the high density of monitoring stations in comparison to the spatial extent of a typical rain event. Reducing the network density improved the accuracy of the map when universal kriging was used instead of ordinary kriging (no trend). Consequently, in a less dense network the positive influence of including a trend is likely to increase. Furthermore, we suspect that UK better reproduces the sharp boundaries present in rainfall maps, but that the lack of short-distance monitoring station pairs prevents cross-validation from revealing this effect.

  10. Applications of FM-CW laser radar to antenna contour mapping

    NASA Technical Reports Server (NTRS)

    Slotwinski, A. R.

    1989-01-01

    The FM-CW coherent laser radar concept, based on the FM radar principle which makes use of the coherence and lunability of injection laser diodes, is discussed. Laser radar precision/time tradeoffs, block diagrams, system performance, fiber optic system implantation, and receiver improvements are briefly described.

  11. Validation of Spaceborne Radar Surface Water Mapping with Optical sUAS Images

    NASA Astrophysics Data System (ADS)

    Li-Chee-Ming, J.; Murnaghan, K.; Sherman, D.; Poncos, V.; Brisco, B.; Armenakis, C.

    2015-08-01

    The Canada Centre for Remote Sensing (CCRS) has over 40 years of experience with airborne and spaceborne sensors and is now starting to use small Unmanned Aerial Systems (sUAS) to validate products from large coverage area sensors and create new methodologies for very high resolution products. Wetlands have several functions including water storage and retention which can reduce flooding and provide continuous flow for hydroelectric generation and irrigation for agriculture. Synthetic Aperture Radar is well suited as a tool for monitoring surface water by supplying acquisitions irrespective of cloud cover or time of day. Wetlands can be subdivided into three classes: open water, flooded vegetation and upland which can vary seasonally with time and water level changes. RADARSAT-2 data from the Wide-Ultra Fine, Spotlight and Fine Quad-Pol modes has been used to map the open water in the Peace-Athabasca Delta, Alberta using intensity thresholding. We also use spotlight modes for higher resolution and the fully polarimetric mode (FQ) for polarimetric decomposition. Validation of these products will be done using a low altitude flying sUAS to generate optical georeferenced images. This project provides methodologies which could be used for flood mapping as well as ecological monitoring.

  12. Surface current patterns in the northern Adriatic extracted from high-frequency radar data using self-organizing map analysis

    NASA Astrophysics Data System (ADS)

    Mihanović, Hrvoje; Cosoli, Simone; Vilibić, Ivica; Ivanković, Damir; Dadić, Vlado; GačIć, Miroslav

    2011-08-01

    A network of high-frequency (HF) radars was installed in the northern Adriatic in the second half of 2007, aimed to measure surface currents in the framework of the North Adriatic Surface Current Mapping (NASCUM) project. This study includes a detailed analysis of current measurements from February to August 2008, a period in which three radars were simultaneously operational. Current patterns and temporal evolutions of different physical processes were extracted by using self-organizing map (SOM) analysis. The analysis focused on subtidal frequency band and extracted 12 different circulation patterns on a 4 × 3 rectangular SOM grid. The SOM was also applied on a joint data set that included contemporaneous surface wind data obtained from the operational hydrostatic mesoscale meteorological model ALADIN/HR. The strongest currents were recorded during energetic bora episodes, being recognized by several current patterns and having the characteristic downwind flow with magnitudes exceeding 35 cm/s at some grid points. Another characteristic wind, the sirocco, was represented by three current patterns, while the remaining current structures were attributed to weak winds and the residual thermohaline circulation. A strong resemblance has been found between SOM patterns extracted from HF radar data only and from combined HF radar and wind data sets, revealing the predominant wind influence to the surface circulation structures and their temporal changes in the northern Adriatic. These results show the SOM analysis being a valuable tool for extracting characteristic surface current patterns and forcing functions.

  13. 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

  14. Automated global water mapping based on wide-swath orbital synthetic aperture radar

    NASA Astrophysics Data System (ADS)

    Westerhoff, R. S.; Kleuskens, M. P. H.; Winsemius, H. C.; Huizinga, H. J.; Brakenridge, G. R.

    2012-06-01

    This paper presents an automated technique, embedded in an online service, which ingests orbital synthetic aperture radar (SAR) imagery and outputs surface water maps in near real time and on a global scale. The service anticipates future open data dissemination of water extent information using the European Space Agency's Sentinel-1 data. The classification methods used are innovative but practical and different per 1 × 1 degree tile. For each tile, a probability distribution function of a pixel, being covered with water or being dry is established based on a long SAR training dataset. These probability distributions are conditional on the backscatter and the incidence angle. In classification mode the probability of water coverage is calculated, conditional on the current backscatter - incidence angle combination. The overlap between the probability distributions of a pixel being wet or dry is used as a proxy for the quality of our classification. The service has multiple uses, e.g. for water body dynamics in times of drought or for urgent inundation extent determination during floods. The service generates data systematically: it is not an on-demand service activated only for emergency response, but instead is always up-to-date and available. We demonstrate its use in flood situations using Envisat ASAR information during the 2011 Thailand floods. A first merge with a NASA near real time water product based on MODIS optical satellite imagery shows excellent agreement between these independent satellite-based water products.

  15. Photogrammetry for Mapping Underground Utility Lines with Ground Penetrating Radar in Urban Areas

    NASA Astrophysics Data System (ADS)

    Cazzaniga, N. E.; Pagliari, D.; Pinto, L.

    2012-07-01

    Ground Penetrating Radar (GPR) is an active instrument often used to detect underground utility locations up to a few meters. To perform a three-dimensional reconstruction of position and geometry of the surveyed features, the accuracy of GPR position data has to be in the order of 20-30 cm. This requirement is easily attainable using a GNSS system in open sky conditions, while in urban areas signal leakage is frequent, leading to inadequate position accuracy or even positioning failure. Usually, in those cases, GPS/INS navigation systems are used, but they are quite an expensive solution. To determine the position of the GPR, another strategy could be utilizing a photogrammetric method that uses information extracted from a large scale map, often available for towns. In this paper, the characteristics of this procedure and some possible configurations of cameras are described. Results obtained from preliminary tests are hereby presented and discussed to demonstrate that the proposed methodology could achieve the required precision.

  16. Mapping sea ice using reflected GNSS signals in a bistatic radar system

    NASA Astrophysics Data System (ADS)

    Chew, Clara; Zuffada, Cinzia; Shah, Rashmi; Mannucci, Anthony

    2016-04-01

    Global Navigation Satellite System (GNSS) signals can be used as a kind of bistatic radar, with receivers opportunistically recording ground-reflected signals transmitted by the GNSS satellites themselves. This technique, GNSS-Reflectometry (GNSS-R), has primarily been explored using receivers flown on aircraft or balloons, or in modeling studies. Last year's launch of the TechDemoSat-1 (TDS-1) satellite represents an enormous opportunity to investigate the potential of using spaceborne GNSS receivers to sense changes in the land and ocean surface. Here, we examine the ability of reflected GNSS signals to estimate sea ice extent and sea ice age, as well as comment on the possibility of using GNSS-R to detect leads and polynyas within the ice. In particular, we quantify how the peak power of Delay Doppler Maps (DDMs) generated within the GNSS receiver responds as the satellite flies over the Polar Regions. To compute the effective peak power of each DDM, we first normalize the peak power of the DDM by the noise floor. We also correct for antenna gain, range, and incidence angle. Once these corrections are made, the effective peak power across DDMs may be used as a proxy for changes in surface permittivity and surface roughness. We compare our calculations of reflected power to existing sea ice remote sensing products such as data from the SSMI/S as well as Landsat imagery. Our analysis shows that GNSS reflections are extremely sensitive to the sea ice edge, with increases in reflected power of more than 10 dB relative to reflected power over the open ocean. As the sea ice ages, it thickens and roughens, and reflected power decreases, though it does not decrease below the power over the open ocean. Given the observed sensitivity of GNSS reflections to small features over land and the sensitivity to the sea ice edge, we hypothesize that reflection data could help map the temporal evolution of leads and polynyas.

  17. Use of radar remote sensing (RADARSAT) to map winter wetland habitat for shorebirds in an agricultural landscape

    USGS Publications Warehouse

    Taft, O.W.; Haig, S.M.; Kiilsgaard, C.

    2003-01-01

    Many of today's agricultural landscapes once held vast amounts of wetland habitat for waterbirds and other wildlife. Successful restoration of these landscapes relies on access to accurate maps of the wetlands that remain. We used C-band (5.6-cm-wavelength), HH-polarized radar remote sensing (RADARSAT) at a 38?? incidence angle (8-m resolution) to map the distribution of winter shorebird (Charadriiformes) habitat on agricultural lands in the Willamette Valley of western Oregon. We acquired imagery on three dates (10 December 1999, 27 January 2000, and 15 March 2000) and simultaneously collected ground reference data to classify radar signatures and evaluate map accuracy of four habitat classes: (1) wet with ??? 50% vegetation (considered optimal shorebird habitat), (2) wet with > 50% vegetation, (3) dry with ??? 50% vegetation, and (4) dry with > 50% vegetation. Overall accuracy varied from 45 to 60% among the three images, but the accuracy of focal class 1 was greater, ranging from 72 to 80%. Class 4 coverage was stable and dominated maps (40% of mapped study area) for all three dates, while class 3 coverage decreased slightly throughout the study period. Among wet classes, class 1 was most abundant (30% coverage) in December and January, decreasing in March by 15%. Conversely, class 2 increased dramatically from January to March, likely due to transition from class 1 as vegetation grew. This approach was successful in detecting optimal habitat for shorebirds on agricultural lands. For modest classification schemes, radar remote sensing is a valuable option for wetland mapping in areas where cloud cover is persistent. ?? 2003 Springer-Verlag New York Inc.

  18. Use of radar remote sensing (RADARSAT) to map winter wetland habitat for shorebirds in an agricultural landscape

    USGS Publications Warehouse

    Taft, Oriane W.; Haig, Susan M.

    2004-01-01

    Many of todays agricultural landscapes once held vast amounts of wetland habitat for waterbirds and other wildlife. Successful restoration of these landscapes relies on access to accurate maps of the wetlands that remain. We used C-band (5.6-cm-wavelength), HH-polarized radar remote sensing (RADARSAT) at a 38A? incidence angle (8-m resolution) to map the distribution of winter shorebird (Charadriiformes) habitat on agricultural lands in the Willamette Valley of western Oregon. We acquired imagery on three dates (10 December 1999, 27 January 2000, and 15 March 2000) and simultaneously collected ground reference data to classify radar signatures and evaluate map accuracy of four habitat classes: (1) wet with 50% vegetation (considered optimal shorebird habitat), (2) wet with > 50% vegetation, (3) dry with 50% vegetation, and (4) dry with > 50% vegetation. Overall accuracy varied from 45 to 60% among the three images, but the accuracy of focal class 1 was greater, ranging from 72 to 80%. Class 4 coverage was stable and dominated maps (40% of mapped study area) for all three dates, while coverage of class 3 decreased slightly throughout the study period. Among wet classes, class 1 was most abundant (about 30% coverage) in December and January, decreasing in March to approximately 15%. Conversely, class 2 increased dramatically from January to March, likely due to transition from class 1 as vegetation grew. This approach was successful in detecting optimal habitat for shorebirds on agricultural lands. For modest classification schemes, radar remote sensing is a valuable option for wetland mapping in areas where cloud cover is persistent.

  19. Surface circulation in the Iroise Sea (western Brittany) derived from high resolution current mapping by HF radars

    NASA Astrophysics Data System (ADS)

    Sentchev, Alexei; Forget, Philippe; Barbin, Yves; Marié, Louis; Ardhuin, Fabrice

    2010-05-01

    The use of high frequency radar (HFR) systems for near-real-time coastal ocean monitoring necessities that short time scale motions of the radar-derived velocities are better understood. While the ocean radar systems are able to describe coastal flow patterns with unprecedented details, the data they produce are often too sparse or gappy for applications such as the identification of coherent structures and fronts or understanding transport and mixing processes. In this study, we address two challenges. First, we report results from the HF radar system (WERA) which is routinely operating since 2006 on the western Brittany coast to monitor surface circulation in the Iroise Sea, over an area extending up to 100 km offshore. To obtain more reliable records of vector current fields at high space and time resolution, the Multiple Signal Classification (MUSIC) direction finding algorithm is employed in conjunction with the variational interpolation (2dVar) of radar-derived velocities. This provides surface current maps at 1 km spacing and time resolution of 20 min. Removing the influence of the sea state on radar-derived current measurements is discussed and performed on some data sequences. Second, we examine in deep continuous 2d velocity records for a number of periods, exploring the different modes of variability of surface currents in the region. Given the extent, duration, and resolution of surface current velocity measurements, new quantitative insights from various time series and spatial analysis on higher frequency kinematics will be discussed. By better characterizing the full spectrum of flow regimes that contribute to the surface currents and their shears, a more complete picture of the circulation in the Iroise Sea can be obtained.

  20. Mapping tropical forest biomass with radar and spaceborne LiDAR: overcoming problems of high biomass and persistent cloud

    NASA Astrophysics Data System (ADS)

    Mitchard, E. T. A.; Saatchi, S. S.; White, L. J. T.; Abernethy, K. A.; Jeffery, K. J.; Lewis, S. L.; Collins, M.; Lefsky, M. A.; Leal, M. E.; Woodhouse, I. H.; Meir, P.

    2011-08-01

    Spatially-explicit maps of aboveground biomass are essential for calculating the losses and gains in forest carbon at a regional to national level. The production of such maps across wide areas will become increasingly necessary as international efforts to protect primary forests, such as the REDD+ (Reducing Emissions from Deforestation and forest Degradation) mechanism, come into effect, alongside their use for management and research more generally. However, mapping biomass over high-biomass tropical forest is challenging as (1) direct regressions with optical and radar data saturate, (2) much of the tropics is persistently cloud-covered, reducing the availability of optical data, (3) many regions include steep topography, making the use of radar data complex, (4) while LiDAR data does not suffer from saturation, expensive aircraft-derived data are necessary for complete coverage. We present a solution to the problems, using a combination of terrain-corrected L-band radar data (ALOS PALSAR), spaceborne LiDAR data (ICESat GLAS) and ground-based data. We map Gabon's Lopé National Park (5000 km2) because it includes a range of vegetation types from savanna to closed-canopy tropical forest, is topographically complex, has no recent cloud-free high-resolution optical data, and the dense forest is above the saturation point for radar. Our 100 m resolution biomass map is derived from fusing spaceborne LiDAR (7142 ICESat GLAS footprints), 96 ground-based plots (average size 0.8 ha) and an unsupervised classification of terrain-corrected ALOS PALSAR radar data, from which we derive the aboveground biomass stocks of the park to be 78 Tg C (173 Mg C ha-1). This value is consistent with our field data average of 181 Mg C ha-1, from the field plots measured in 2009 covering a total of 78 ha, and which are independent as they were not used for the GLAS-biomass estimation. We estimate an uncertainty of ± 25 % on our carbon stock value for the park. This error term includes

  1. Improved Discrimination of Volcanic Complexes, Tectonic Features, and Regolith Properties in Mare Serenitatis from Earth-Based Radar Mapping

    NASA Technical Reports Server (NTRS)

    Campbell, Bruce A.; Hawke, B. Ray; Morgan, Gareth A.; Carter, Lynn M.; Campbell, Donald B.; Nolan, Michael

    2014-01-01

    Radar images at 70 cm wavelength show 4-5 dB variations in backscatter strength within regions of relatively uniform spectral reflectance properties in central and northern Mare Serenitatis, delineating features suggesting lava flow margins, channels, and superposition relationships. These backscatter differences are much less pronounced at 12.6 cm wavelength, consistent with a large component of the 70 cm echo arising from the rough or blocky transition zone between the mare regolith and the intact bedrock. Such deep probing is possible because the ilmenite content, which modulates microwave losses, of central Mare Serenitatis is generally low (2-3% by weight). Modeling of the radar returns from a buried interface shows that an average regolith thickness of 10m could lead to the observed shifts in 70 cm echo power with a change in TiO2 content from 2% to 3%. This thickness is consistent with estimates of regolith depth (10-15m) based on the smallest diameter for which fresh craters have obvious blocky ejecta. The 70 cm backscatter differences provide a view of mare flow-unit boundaries, channels, and lobes unseen by other remote sensing methods. A localized pyroclastic deposit associated with Rima Calippus is identified based on its low radar echo strength. Radar mapping also improves delineation of units for crater age dating and highlights a 250 km long, east-west trending feature in northern Mare Serenitatis that we suggest is a large graben flooded by late-stage mare flows.

  2. Mapping Wetlands of Alaska and Western Canada from Satellite Radar Imagery

    NASA Astrophysics Data System (ADS)

    Moghaddam, M.; McDonald, K. C.; Cihlar, J.; Chen, W.

    2002-12-01

    Boreal wetlands have an important function in processing methane, carbon dioxide, nitrogen, and sulfur as well as in sequestering carbon. The type and extent of high latitude wetlands are important indicators of methane source areas, while upland forests in the taiga are important methane-consuming sinks. Wetlands regulate biogeochemical processes such as methane production, and fix and store organic matter in the long run. The extent and complexity of wetland ecosystems are still quite uncertain partly because it is difficult to discriminate wetlands on a global scale using widely available optical remote sensing data and techniques, which are not able to detect standing water conditions under most vegetation. The accurate assessment of areal and temporal distributions of wetlands can have a large impact in improving the estimates of the global net carbon exchange. Synthetic Aperture Radar (SAR) sensors are well suited to monitoring wetlands because of their ability to detect various combinations of standing water and vegetation structure and moisture conditions. SARs also penetrate cloud cover and do not require solar illumination, allowing the collection of frequent seasonal data. Multifrequency, multipolarization SAR data needed to classify various wetlands types have been available for several years from airborne systems. Although existing spaceborne SAR data are limited to single frequency and single polarization configurations, combining data from different SAR satellites can emulate a space-based multifrequency multipolarization capability. No large-scale wetlands mapping efforts have been carried out thus far due unavailability of appropriate SAR data sets. However, with the recent availability of the JERS-1 north American boreal mosaic augmented by the partial ERS-2 overlapping data, it is now possible to generate maps of wetland extent, as well as set the stage for performing time-series analysis with future planned SAR satellite systems. We present a

  3. Marsh dieback, loss, and recovery mapped with satellite optical, airborne polarimetric radar, and field data

    USGS Publications Warehouse

    Ramsey, Elijah W.; Rangoonwala, Amina; Chi, Zhaohui; Jones, Cathleen E.; Bannister, Terri

    2014-01-01

    Landsat Thematic Mapper and Satellite Pour l'Observation de la Terre (SPOT) satellite based optical sensors, NASA Uninhabited Aerial Vehicle synthetic aperture radar (UAVSAR) polarimetric SAR (PolSAR), and field data captured the occurrence and the recovery of an undetected dieback that occurred between the summers of 2010, 2011, and 2012 in the Spartina alterniflora marshes of coastal Louisiana. Field measurements recorded the dramatic biomass decrease from 2010 to 2011 and a biomass recovery in 2012 dominated by a decrease of live biomass, and the loss of marsh as part of the dieback event. Based on an established relationship, the near-infrared/red vegetation index (VI) and site-specific measurements delineated a contiguous expanse of marsh dieback encompassing 6649.9 ha of 18,292.3 ha of S. alterniflora marshes within the study region. PolSAR data were transformed to variables used in biophysical mapping, and of this variable suite, the cross-polarization HV (horizontal send and vertical receive) backscatter was the best single indicator of marsh dieback and recovery. HV backscatter exhibited substantial and significant changes over the dieback and recovery period, tracked measured biomass changes, and significantly correlated with the live/dead biomass ratio. Within the context of regional trends, both HV and VI indicators started higher in pre-dieback marshes and exhibited substantially and statistically higher variability from year to year than that exhibited in the non-dieback marshes. That distinct difference allowed the capturing of the S. alterniflora marsh dieback and recovery; however, these changes were incorporated in a regional trend exhibiting similar but more subtle biomass composition changes.

  4. Application of multispectral radar and LANDSAT imagery to geologic mapping in death valley

    NASA Technical Reports Server (NTRS)

    Daily, M.; Elachi, C.; Farr, T.; Stromberg, W.; Williams, S.; Schaber, G.

    1978-01-01

    Side-Looking Airborne Radar (SLAR) images, acquired by JPL and Strategic Air Command Systems, and visible and near-infrared LANDSAT imagery were applied to studies of the Quaternary alluvial and evaporite deposits in Death Valley, California. Unprocessed radar imagery revealed considerable variation in microwave backscatter, generally correlated with surface roughness. For Death Valley, LANDSAT imagery is of limited value in discriminating the Quaternary units except for alluvial units distinguishable by presence or absence of desert varnish or evaporite units whose extremely rough surfaces are strongly shadowed. In contrast, radar returns are most strongly dependent on surface roughness, a property more strongly correlated with surficial geology than is surface chemistry.

  5. Mapping preferential flow pathways in a riparian wetland using ground-penetrating radar

    NASA Astrophysics Data System (ADS)

    Gormally, Kevin Hill

    Preferential flow of water through channels in the soil has been implicated as a vehicle for groundwater and surface water contamination in forested riparian wetland buffers. Water conducted through these by-pass channels can circumvent interaction with wetland biota, biomass, and soils, thereby reducing the buffering capacity of the riparian strips for adsorption and uptake of excess nutrient loads from neighboring agricultural fields and urbanized lands. Models of riparian function need to account for preferential flow to accurately estimate nutrient flux to stream channels, but there are currently no methods for determining the form and prevalence of these pathways outside of extensive destructive sampling. This research developed, tested, and validated a new application of non-invasive ground-penetrating radar technology (GPR) for mapping the three-dimensional structure of near-surface (0-1 m) lateral preferential flow channels. Manual and automated detection methodologies were created for analyzing GPR scan data to locate the channels in the subsurface. The accuracy of the methodologies was assessed in two field test plots with buried PVC pipes simulating the riparian channels. The manual methodology had a 0% Type I error rate and 8% Type II error rate; the automated version had a <1% Type I error rate and 29% Type II error rate. An automated mapping algorithm was also created to reconstruct channel geometries from the scan data detections. The algorithm was shown to robustly track the connectivity of PVC pipe segments arranged in a branching structure hypothesized to exist in the riparian soils. These methods and algorithms were then applied at a riparian wetland study site at USDA Beltsville Agricultural Research Center in Beltsville, MD. The predicted structure of preferential flow channels in the wetland was validated by transmission of tracer dye through the study site and ground truth generated from soil core samples (92% accurate). These GPR tools will

  6. Mapping Fractures in KAERI Underground Research Tunnel using Ground Penetrating Radar

    NASA Astrophysics Data System (ADS)

    Baek, Seung-Ho; Kim, Seung-Sep; Kwon, Jang-Soon

    2016-04-01

    The proportion of nuclear power in the Republic of Korea occupies about 40 percent of the entire electricity production. Processing or disposing nuclear wastes, however, remains one of biggest social issues. Although low- and intermediate-level nuclear wastes are stored temporarily inside nuclear power plants, these temporary storages can last only up to 2020. Among various proposed methods for nuclear waste disposal, a long-term storage using geologic disposal facilities appears to be most highly feasible. Geological disposal of nuclear wastes requires a nuclear waste repository situated deep within a stable geologic environment. However, the presence of small-scale fractures in bedrocks can cause serious damage to durability of such disposal facilities because fractures can become efficient pathways for underground waters and radioactive wastes. Thus, it is important to find and characterize multi-scale fractures in bedrocks hosting geologic disposal facilities. In this study, we aim to map small-scale fractures inside the KAERI Underground Research Tunnel (KURT) using ground penetrating radar (GPR). The KURT is situated in the Korea Atomic Energy Research Institute (KAERI). The survey target is a section of wall cut by a diamond grinder, which preserves diverse geologic features such as dykes. We conducted grid surveys on the wall using 500 MHz and 1000 MHz pulseEKKO PRO sensors. The observed GPR signals in both frequencies show strong reflections, which are consistent to form sloping planes. We interpret such planar features as fractures present in the wall. Such fractures were also mapped visually during the development of the KURT. We confirmed their continuity into the wall from the 3D GPR images. In addition, the spatial distribution and connectivity of these fractures are identified from 3D subsurface images. Thus, we can utilize GPR to detect multi-scale fractures in bedrocks, during and after developing underground disposal facilities. This study was

  7. U.S. national categorical mapping of building heights by block group from Shuttle Radar Topography Mission data

    USGS Publications Warehouse

    Falcone, James

    2016-01-01

    This dataset is a categorical mapping of estimated mean building heights, by Census block group, in shapefile format for the conterminous United States. The data were derived from the NASA Shuttle Radar Topography Mission, which collected “first return” (top of canopy and buildings) radar data at 30-m resolution in February, 2000 aboard the Space Shuttle Endeavor. These data were processed here to estimate building heights nationally, and then aggregated to block group boundaries. The block groups were then categorized into six classes, ranging from “Low” to “Very High”, based on the mean and standard deviation breakpoints of the data. The data were evaluated in several ways, to include comparing them to a reference dataset of 85,000 buildings for the city of San Francisco for accuracy assessment and to provide contextual definitions for the categories.

  8. Landslide Hazard Mapping Using Ground-based Interferometric Radar in the Fjords of South-Central Alaska

    NASA Astrophysics Data System (ADS)

    Balazs, M. S.; Meyer, F. J.; Bollian, T.; Wolken, G. J.; Prakash, A.

    2013-12-01

    The cities of Seward and Whittier, Alaska are situated at the base of steep walls within two fjords located on the Kenai Peninsula. Historic events have shown that the combination of terrain, geology, and vegetation are factors which can lead to significant events of erosion in the surrounding slopes during periods of heavy rainfall. While other remote sensing techniques have been shown to be useful for accessing landslide hazards, local surface processes may be better understood to create more accurate hazard maps and predictive models by using data gained from interferometric radar. To gain perspective into where, and at which speed, slopes are deforming, we utilize the GPRI-2 terrestrial interferometric radar system which transmits signals in the Ku band. The GPRI-2 portable radar unit has several advantages to space-borne radar, including relative freedom of site selection and regions to target, ability to determine temporal baselines, and repeat acquisitions which can be collected with a zero spatial-baseline. There are however, problems which need to be addressed when using such a system in the fjord environments, and in particular for monitoring slope deformation in these areas. Foremost, the noise that is attributed to the atmosphere is of great concern as it is sometimes required to position the radar several kilometers away from the target, across open water. We offer our results of correcting for this interference and report the results. Secondly, we address the issue of repeat acquisitions over long periods of time, which is needed to detect movements in the slope, and report on the decorrelation of the signal in the various land cover types in the study areas. Finally, we offer suggestions of the usefulness of such a system to detect slope deformation in similar environments.

  9. Effects of Analog-to-Digital Converter Nonlinearities on Radar Range-Doppler Maps

    SciTech Connect

    Doerry, Armin Walter; Dubbert, Dale F.; Tise, Bertice L.

    2014-07-01

    Radar operation, particularly Ground Moving Target Indicator (GMTI) radar modes, are very sensitive to anomalous effects of system nonlinearities. These throw off harmonic spurs that are sometimes detected as false alarms. One significant source of nonlinear behavior is the Analog to Digital Converter (ADC). One measure of its undesired nonlinearity is its Integral Nonlinearity (INL) specification. We examine in this report the relationship of INL to GMTI performance.

  10. Early geomorphological evolution of the North Polar Layered Deposits, Mars, from SHARAD radar-facies mapping

    NASA Astrophysics Data System (ADS)

    Nerozzi, Stefano; Holt, John W.

    2014-05-01

    The north polar layered deposits (NPLD) are the largest accumulation of water ice in the northern hemisphere of Mars. Since their discovery, they are thought to hold a valuable record of recent climate change within their stratigraphy (Murray et al., Icarus, 1972; Cutts, JGR, 1973b), yet little is known about their age and accumulation history. Due to exposures in trough walls, detailed stratigraphy of the uppermost layers and their evolution have been studied extensively since the first Mariner 9 images of the NPLD (e.g. Soderblom et al., JGR, 1973). However, large portions of the polar cap are still unmapped and no detailed studies of the lowermost layered deposits have been performed to date, primarily due to a general lack of visible exposures. Correlation of reflectors within radargrams acquired by the Shallow Radar (SHARAD) (Seu et al., Planet. Space Sci., 2004) onboard Mars Reconnaissance Orbiter makes a detailed stratigraphic reconstruction of the NPLD possible. An extensive set of radargrams is available over Planum Boreum and individual reflectors can be traced over hundreds of kilometers (Seu et al., JGR, 2007a; Putzig et al., Icarus, 2009; Holt et al., Nature, 2010) with a theoretical vertical resolution of ~9 m in water ice (Seu et al., JGR, 2007a). In this study, we present a highly-detailed stratigraphic reconstruction of the first ~500 m of the NPLD at a scale down to the single reflector. A set of 8 horizons was tracked across 700+ radargrams, and thicknesses were calculated for each stratigraphic interval assuming a bulk composition of water ice. Along with the quantitative analysis of derived isopach maps, this study is based on the qualitative comparison of "radar facies" in different locations of Planum Boreum with techniques borrowed from traditional sequence stratigraphy. In general, the NPLD is characterized by uniform layering. However, important layer extent and thickness variations are observed within the lowermost sequence. Limited

  11. Mapping Stratigraphy and Anomalies in Iron-Rich Volcanoclastics Using Ground-Penetrating Radar: Potential for Subsurface Exploration on Mars

    NASA Astrophysics Data System (ADS)

    Heggy, E.; Clifford, S.; Khan, S.; Fernandez, J.; Wiggs, E.; Gonzalez, S. L.; Wyrick, D.; Grimm, R.; Dinwiddie, C.; Pommerol, A.

    2004-12-01

    Ground-penetrating radar (GPR) studies conducted in iron-rich volcanoclastics can yield valuable information for interpreting the subsurface stratigraphy resulting from lava flows and intervening unconsolidated volcanic and sedimentary deposits with different compositions and ages. GPR is also valuable for mapping subsurface anomalies and structures, such as rifts and lava tubes. We performed a geophysical field survey in Craters of the Moon National Park to evaluate the potential for using GPR to map local areas of the Martian subsurface for evidence of subsurface water. Craters of the Moon is located in the South Central portion of Idaho, and lies within the Eastern Snake River Plain; it is a composite of more than forty different lava flows, erupted from approximately twenty-five cinder cones and eruptive fissures over eight distinct eruptive periods ranging in age from Late Pleistocene to Holocene. We used a GPR operating at 16 and 100 MHz to perform structural mapping at several different locations. Radar studies were combined with transient electromagnetic soundings and infrared spectroscopy to assess the effect of soil conductivity and geochemistry on identification of subsurface structures. Our results show that, even with a relatively high amount of irons oxides (~14 %), GPR penetration depths of 50 m were achieved with the 100 MHz antenna and penetration depths of 150 m were achieved with the 16 MHz antenna. These depths of investigation may be attributable to the high porosity of the soil at the studied areas, which lowered the electrical losses, thus favoring a relatively deep penetration of the radar wave.

  12. Surface Ruptures and Building Damage of the 2003 Bam, Iran, Earthquake Mapped by Satellite Synthetic Aperture Radar Interferometric Correlation

    NASA Technical Reports Server (NTRS)

    Fielding, Eric J.; Talebian, M.; Rosen, P. A.; Nazari, H.; Jackson, J. A.; Ghorashi, M.; Walker, R.

    2005-01-01

    We use the interferometric correlation from Envisat synthetic aperture radar (SAR) images to map the details of the surface ruptures related to the 26 December 2003 earthquake that devastated Bam, Iran. The main strike-slip fault rupture south of the city of Bam has a series of four segments with left steps shown by a narrow line of low correlation in the coseismic interferogram. This also has a clear expression in the field because of the net extension across the fault. Just south of the city limits, the surface strain becomes distributed over a width of about 500 m, probably because of a thicker layer of soft sedimentary material.

  13. Mapping of Bare Soil Surface Parameters (Moisture, Roughness, Texture) from one TerraSAR-X Radar Configuration

    NASA Astrophysics Data System (ADS)

    Zribi, Mehrez; Gorrab, Azza; Baghdadi, Nicolas; Chabaane, Zohra Lili

    2016-08-01

    In this paper, surface bare soil parameters (moisture, roughness and texture) mapping was carried out in central Tunisia (North Africa) using one TerraSAR-X radar configuration (one incidence angle, one polarization). Firstly, we analyzed statistically the relationships between TerraSAR-X backscattering signals function of soil moisture and different roughness parameters (the root mean square height Hrms, the Zs and the Zg parameters) at 36° and HH polarization. Results have shown a high sensitivity of real radar data to all soil parameters. Then, we proposed an algorithm combing the TerraSAR-X images with different continuous thetaprobe measurements for the retrieval of surface soil moisture. Empirical relationship was established between the mean moisture values retrieved from the SAR images and the percentage of clay over 36 test fields. Validation of the proposed approach was carried out over a second set of 34 fields, showing that highly accurate clay estimations can be achieved. Finally, for spatial and temporal surface roughness estimation, we proposed empirical relationships between radar and soil roughness parameters (Hrms and Zg parameters). The proposed model was calibrated over 39 test fields, and then validated over 40 other plots.

  14. Lunar radar backscatter studies

    NASA Technical Reports Server (NTRS)

    Thompson, T. W.

    1979-01-01

    The lunar surface material in the Plato area is characterized using Earth based visual, infrared, and radar signatures. Radar scattering in the lunar regolith with an existing optical scattering computer program is modeled. Mapping with 1 to 2 km resolution of the Moon using a 70 cm Arecibo radar is presented.

  15. The evaluation of 3cm-wavelength radar for mapping surface deposits in the Bristol Lake/Granite Mountain area, Mojave Desert, California

    NASA Technical Reports Server (NTRS)

    Sugiura, R.; Sabins, F. F., Jr.

    1980-01-01

    Surface deposits in the Bristol Lake/Granite Mountains area, Mojave Desert, California were mapped using high resolution 3 cm wavelength radar images. The surface deposits range from silt to boulders in size and were separated into six radar-rock units on the basis of radar return signatures (brightness and texture) and geomorphic expression. Field reconnaissance of the six units showed that the brightness of the radar signatures on the images correlates with the surface roughness of each unit. Two major radar signatures anomalies were noted during the study. A dark radar signature for the large sand ridges in the Kelso Dunes area and a distinct northwest trending contrast boundary between bright and dark radar signatures in the Bristol Dry Lake area. Field reconnaissance of the two areas indicated that near surface moisture may be the cause of dark signatures. Dune areas with little to no vegetation produce a dark signature, whereas areas with sparse to moderate vegetation produce an intermediate to dark signature.

  16. Precise Pointing for Radio Science Occultations and Radar Mapping During the Cassini Mission at Saturn

    NASA Technical Reports Server (NTRS)

    Burk, Thomas A.

    2015-01-01

    This paper discusses the implementation challenges and lessons learned from radar and radio science pointing observations during the Cassini mission at Saturn. Implementation of the precise desired pointing reveals key issues in the ground system, the flight system, and the pointing paradigm itself. To achieve accurate pointing on some observations, specific workarounds had to be implemented and folded into the sequence development process. Underlying Cassini's pointing system is a remarkable construct known as Inertial Vector Propagation.

  17. A constant altitude flight survey method for mapping atmospheric ambient pressures and systematic radar errors

    NASA Technical Reports Server (NTRS)

    Larson, T. J.; Ehernberger, L. J.

    1985-01-01

    The flight test technique described uses controlled survey runs to determine horizontal atmospheric pressure variations and systematic altitude errors that result from space positioning measurements. The survey data can be used not only for improved air data calibrations, but also for studies of atmospheric structure and space positioning accuracy performance. The examples presented cover a wide range of radar tracking conditions for both subsonic and supersonic flight to an altitude of 42,000 ft.

  18. Global digital topography mapping with a synthetic aperture scanning radar altimeter

    NASA Technical Reports Server (NTRS)

    Elachi, C.; Im, K. E.; Rodriguez, E.

    1990-01-01

    Global digital topography data of the land surface is of importance in a variety of geoscientific and application disciplines. Such a database, with a spatial resolution of 150 to 500 m and height accuracy of 5 m or better can be acquired from an orbiting platform using a synthetic aperture scanning radar altimeter. Near-global coverage can be achieved within 14 days from an orbiting platform in a polar or near-polar orbit.

  19. Mapping Ocean Surface Topography with a Synthetic-Aperture Interferometry Radar

    NASA Technical Reports Server (NTRS)

    Fu, Lee-Lueng; Rodriguez, Ernesto

    2006-01-01

    We propose to apply the technique of synthetic aperture radar interferometry to the measurement of ocean surface topography at spatial resolution approaching 1 km. The measurement will have wide ranging applications in oceanography, hydrology. and marine geophysics. The oceanographic and related societal applications are briefly discussed in the paper. To meet the requirements for oceanographic applications, the instrument must be flown in an orbit with proper sampling of ocean tides.

  20. Mapping Precambrian structures in the Sahara Desert with SIR-C/X-SAR radar: The Neoproterozoic Keraf Suture, NE Sudan

    NASA Astrophysics Data System (ADS)

    Abdelsalam, Mohamed G.; Stern, Robert J.

    1996-10-01

    A major N-trending Neoproterozoic suture between composite arc terranes of the Arabian-Nubian Shield in the east and older crust of the Nile Craton to the west is inferred to trend N-S close to the Nile in northern Sudan. We used shuttle imaging radar (SIR) C/X synthetic aperture radar (SAR) imagery to find and map these structures in the poorly known Keraf Suture which are not apparent on visible or near IR imagery due to extensive sand cover. L band (23 cm wavelength) radar images best resolve geologic structure; the other frequencies of the SIR-C/X-SAR system (X and C bands) permit qualitative evaluation of the effects of surface versus subsurface backscattering. Interpretation of L band images supported by field work indicates that the Keraf Suture is ~50 km wide and >550 km long, making it the longest basement structure recognized to date in NE Africa. The northern part of the Suture comprises ophiolitic rocks which were thrust westward over tightly folded sediments of the Nile Craton. The southern Keraf Suture is dominated by N- and NNW-trending, left-lateral strike-slip faults that affect previously deformed passive margin sediments. Associated with these faults are NE-trending transpressional folds and a possible transtensional basin. These structures are interpreted to be due to NW-SE oblique collision between the Arabian-Nubian Shield and the Nile Craton, as east and west Gondwana collided in the last 150 m.y. of Neoproterozoic time.

  1. Evaluating of the rain effect on tropical rainfall mapping mission precipitation radar backscatter at low incidence angles

    NASA Astrophysics Data System (ADS)

    Ren, Lin; Yang, Jingsong; Zheng, Gang; Wang, Juan

    2016-10-01

    This paper evaluates the rain effects on Ku-band radar backscatter at low incidence angles. The data used consisted of the sea surface backscatter and averaged rain rates from Tropical Rainfall Mapping Mission precipitation radar (TRMM PR) measurements and the collocated 10-m height numerical prediction wind speeds from the European Centre for Medium-Range Weather Forecasts (ECMWF). The wind-induced backscatter was estimated by the Ku-band low incidence backscatter model (KuLMOD) and possible bias due to different wind speed inputs was considered. The rain effect was analysed by comparing the TRMM PR-measured surface backscatter for the rain-affected sea surface with the collocated wind-induced backscatter. We found that the surface backscatter decreases with increases in the averaged rain rate. The rain-induced backscatter was clearly dependent of the wind speed and was slightly dependent of the incidence angle. Results show that it is necessary to develop a wind and rain backscatter model instead of single wind backscatter model.

  2. Mapping forested wetlands in the Great Zhan River Basin through integrating optical, radar, and topographical data classification techniques.

    PubMed

    Na, X D; Zang, S Y; Wu, C S; Li, W L

    2015-11-01

    Knowledge of the spatial extent of forested wetlands is essential to many studies including wetland functioning assessment, greenhouse gas flux estimation, and wildlife suitable habitat identification. For discriminating forested wetlands from their adjacent land cover types, researchers have resorted to image analysis techniques applied to numerous remotely sensed data. While with some success, there is still no consensus on the optimal approaches for mapping forested wetlands. To address this problem, we examined two machine learning approaches, random forest (RF) and K-nearest neighbor (KNN) algorithms, and applied these two approaches to the framework of pixel-based and object-based classifications. The RF and KNN algorithms were constructed using predictors derived from Landsat 8 imagery, Radarsat-2 advanced synthetic aperture radar (SAR), and topographical indices. The results show that the objected-based classifications performed better than per-pixel classifications using the same algorithm (RF) in terms of overall accuracy and the difference of their kappa coefficients are statistically significant (p<0.01). There were noticeably omissions for forested and herbaceous wetlands based on the per-pixel classifications using the RF algorithm. As for the object-based image analysis, there were also statistically significant differences (p<0.01) of Kappa coefficient between results performed based on RF and KNN algorithms. The object-based classification using RF provided a more visually adequate distribution of interested land cover types, while the object classifications based on the KNN algorithm showed noticeably commissions for forested wetlands and omissions for agriculture land. This research proves that the object-based classification with RF using optical, radar, and topographical data improved the mapping accuracy of land covers and provided a feasible approach to discriminate the forested wetlands from the other land cover types in forestry area.

  3. Radar mapping, archaeology, and ancient land use in the Maya lowlands

    NASA Technical Reports Server (NTRS)

    Adams, R. E. W.; Brown, W. E., Jr.; Culbert, T. P.

    1981-01-01

    Data from the use of synthetic aperture radar in aerial survey of the southern Maya lowlands suggest the presence of very large areas drained by ancient canals for the purpose of intensive cultivation. Preliminary ground checks in several very limited areas confirm the existence of canals and raised fields. Excavations and ground surveys by several scholars provide valuable comparative information. Taken together, the new data suggest that Late Classic period Maya civilization was firmly grounded in large-scale and intensive cultivation of swampy zones.

  4. Surface Circulation in the Iroise Sea (W. Brittany) from High Resolution HF Radar Mapping

    DTIC Science & Technology

    2013-01-01

    surface, Weber and Barrick (1977) slightly modified this relationship accounting for all types of the surface gravity waves. Broche et al. (1983) provided...f0∫2π0 f kE f ; θð Þdf dθ; ðA2Þ with f the wave frequency, k the wavenumber and E(f,θ) the sea sur- face elevation spectrum. Uss writes as ( Broche et...161–182. Broche , P., De Maistre, J.C., Forget, P., 1983. Mesure par radar décamétrique cohérent des courants superficiels engendrés par le vent

  5. Mapping and interpretation of Sinlap crater on Titan using Cassini VIMS and RADAR data

    USGS Publications Warehouse

    Le, Mouelic S.; Paillou, P.; Janssen, M.A.; Barnes, J.W.; Rodriguez, S.; Sotin, C.; Brown, R.H.; Baines, K.H.; Buratti, B.J.; Clark, R.N.; Crapeau, M.; Encrenaz, P.J.; Jaumann, R.; Geudtner, D.; Paganelli, F.; Soderblom, L.; Tobie, G.; Wall, S.

    2008-01-01

    Only a few impact craters have been unambiguously detected on Titan by the Cassini-Huygens mission. Among these, Sinlap is the only one that has been observed both by the RADAR and VIMS instruments. This paper describes observations at centimeter and infrared wavelengths which provide complementary information about the composition, topography, and surface roughness. Several units appear in VIMS false color composites of band ratios in the Sinlap area, suggesting compositional heterogeneities. A bright pixel possibly related to a central peak does not show significant spectral variations, indicating either that the impact site was vertically homogeneous, or that this area has been recovered by homogeneous deposits. Both VIMS ratio images and dielectric constant measurements suggest the presence of an area enriched in water ice around the main ejecta blanket. Since the Ku-band SAR may see subsurface structures at the meter scale, the difference between infrared and SAR observations can be explained by the presence of a thin layer transparent to the radar. An analogy with terrestrial craters in Libya supports this interpretation. Finally, a tentative model describes the geological history of this area prior, during, and after the impact. It involves mainly the creation of ballistic ejecta and an expanding plume of vapor triggered by the impact, followed by the redeposition of icy spherules recondensed from this vapor plume blown downwind. Subsequent evolution is then driven by erosional processes and aeolian deposition. Copyright 2008 by the American Geophysical Union.

  6. Test of the radar fracture mapping tool in a lake using a known target

    SciTech Connect

    Duda, L.E.; Chang, Hsi-Tien; Uhl, J.E.; Gabaldon, J.

    1987-01-01

    A method to locate fractures adjacent to but not intersecting a wellbore would be a great aid to the geothermal industry. A prototype downhole radar probe was recently completed with the aim of locating fractures near a single wellbore. This probe, operating in the pulse mode with a bandwidth of 30 to 300 MHz, contains two identical directional antennas. As with any prototype instrumentation, extensive field work is required to completely understand the characteristics of the system. A first step in that understanding is to operate the instrument under known or controlled conditions. In this paper, a series of tests of the radar probe in a lake using a known target are reported. In the tests, signals reflected from the target were observed when the target was 5 ft and 9 ft from the probe; in the latter case the returned signal was greatly attenuated by the water. The measured 3 dB beamwidth of the system to the target was 70 degrees. Finally, the effect of target size was studied by moving the probe across the face of the target.

  7. Side looking radar calibration study

    NASA Technical Reports Server (NTRS)

    Edwards, W. D.

    1975-01-01

    Calibration of an airborne sidelooking radar is accomplished by the use of a model that relates the radar parameters to the physical mapping situation. Topics discussed include: characteristics of the transmitters; the antennas; target absorption and reradiation; the receiver and map making or radar data processing; and the calibration process.

  8. Mesoscale Near-Surface Wind Speed Variability Mapping with Synthetic Aperture Radar.

    PubMed

    Young, George; Sikora, Todd; Winstead, Nathaniel

    2008-11-05

    Operationally-significant wind speed variability is often observed within synthetic aperture radar-derived wind speed (SDWS) images of the sea surface. This paper is meant as a first step towards automated distinguishing of meteorological phenomena responsible for such variability. In doing so, the research presented in this paper tests feature extraction and pixel aggregation techniques focused on mesoscale variability of SDWS. A sample of twenty eight SDWS images possessing varying degrees of near-surface wind speed variability were selected to serve as case studies. Gaussian high- and low-pass, local entropy, and local standard deviation filters performed well for the feature extraction portion of the research while principle component analysis of the filtered data performed well for the pixel aggregation. The findings suggest recommendations for future research.

  9. Advanced Interferometric Synthetic Aperture Imaging Radar (InSAR) for Dune Mapping

    NASA Astrophysics Data System (ADS)

    Havivi, Shiran; Amir, Doron; Schvartzman, Ilan; August, Yitzhak; Mamman, Shimrit; Rotman, Stanely R.; Blumberg, Dan G.

    2016-04-01

    Aeolian morphologies are formed in the presence of sufficient wind energy and available lose particles. These processes occur naturally or are further enhanced or reduced by human intervention. The dimensions of change are dependent primarily on the wind energy and surface properties. Since the 1970s, remote sensing imagery, both optical and radar, have been used for documentation and interpretation of the geomorphologic changes of sand dunes. Remote sensing studies of aeolian morphologies is mostly useful to document major changes, yet, subtle changes, occurring in a period of days or months in scales of centimeters, are very difficult to detect in imagery. Interferometric Synthetic Aperture Radar (InSAR) is an imaging technique for measuring Earth's surface topography and deformation. InSAR images are produced by measuring the radar phase difference between two separated antennas that view the same surface area. Classical InSAR is based on high coherence between two or more images. The output (interferogram) can show subtle changes with an accuracy of several millimeters to centimeters. Very little work has been done on measuring or identifying the changes in dunes using InSAR methods. The reason is that dunes tend to be less coherent than firm, stable, surfaces. This work aims to demonstrate how interferometric decorrelation can be used for identifying dune instability. We hypothesize and demonstrate that the loss of radar coherence over time on dunes can be used as an indication of the dune's instability. When SAR images are acquired at sufficiently close intervals one can measure the time it takes to lose coherence and associate this time with geomorphic stability. To achieve our goals, the coherence change detection method was used, in order to identify dune stability or instability and the dune activity level. The Nitzanim-Ashdod coastal dunes along the Mediterranean, 40 km south of Tel-Aviv, Israel, were chosen as a case study. The dunes in this area are of

  10. Full-polarization radar remote sensing and data mining for tropical crops mapping: a successful SVM-based classification model

    NASA Astrophysics Data System (ADS)

    Denize, J.; Corgne, S.; Todoroff, P.; LE Mezo, L.

    2015-12-01

    In Reunion, a tropical island of 2,512 km², 700 km east of Madagascar in the Indian Ocean, constrained by a rugged relief, agricultural sectors are competing in highly fragmented agricultural land constituted by heterogeneous farming systems from corporate to small-scale farming. Policymakers, planners and institutions are in dire need of reliable and updated land use references. Actually conventional land use mapping methods are inefficient under the tropic with frequent cloud cover and loosely synchronous vegetative cycles of the crops due to a constant temperature. This study aims to provide an appropriate method for the identification and mapping of tropical crops by remote sensing. For this purpose, we assess the potential of polarimetric SAR imagery associated with associated with machine learning algorithms. The method has been developed and tested on a study area of 25*25 km thanks to 6 RADARSAT-2 images in 2014 in full-polarization. A set of radar indicators (backscatter coefficient, bands ratios, indices, polarimetric decompositions (Freeman-Durden, Van zyl, Yamaguchi, Cloude and Pottier, Krogager), texture, etc.) was calculated from the coherency matrix. A random forest procedure allowed the selection of the most important variables on each images to reduce the dimension of the dataset and the processing time. Support Vector Machines (SVM), allowed the classification of these indicators based on a learning database created from field observations in 2013. The method shows an overall accuracy of 88% with a Kappa index of 0.82 for the identification of four major crops.

  11. A Radar/Radiometer Instrument for Mapping Soil Moisture and Ocean Salinity

    NASA Technical Reports Server (NTRS)

    Hildebrand, Peter H.; Hilliard, Laurence; Rincon, Rafael; LeVine, David; Mead, James

    2003-01-01

    The RadSTAR instrument combines an L-band, digital beam-forming radar with an L-band synthetic aperture, thinned array (STAR) radiometer. The RadSTAR development will support NASA Earth science goals by developing a novel, L-band scatterometer/ radiometer that measures Earth surface bulk material properties (surface emissions and backscatter) as well as surface characteristics (backscatter). Present, real aperture airborne L-Band active/passive measurement systems such as the JPUPALS (Wilson, et al, 2000) provide excellent sampling characteristics, but have no scanning capabilities, and are extremely large; the huge JPUPALS horn requires a the C-130 airborne platform, operated with the aft loading door open during flight operation. The approach used for the upcoming Aquarius ocean salinity mission or the proposed Hydros soil mission use real apertures with multiple fixed beams or scanning beams. For real aperture instruments, there is no upgrade path to scanning over a broad swath, except rotation of the whole aperture, which is an approach with obvious difficulties as aperture size increases. RadSTAR will provide polarimetric scatterometer and radiometer measurements over a wide swath, in a highly space-efficient configuration. The electronic scanning approaches provided through STAR technology and digital beam forming will enable the large L-band aperture to scan efficiently over a very wide swath. RadSTAR technology development, which merges an interferometric radiometer with a digital beam forming scatterometer, is an important step in the path to space for an L-band scatterometer/radiometer. RadSTAR couples a patch array antenna with a 1.26 GHz digital beam forming radar scatterometer and a 1.4 GHz STAR radiometer to provide Earth surface backscatter and emission measurements in a compact, cross-track scanning instrument with no moving parts. This technology will provide the first L-band, emission and backscatter measurements in a compact aircraft instrument

  12. Biomass Mapping of US forests using synergy of Synthetic Aperture Radar and optical Remote Sensing

    NASA Astrophysics Data System (ADS)

    Kellndorfer, J. M.; Baccini, A.; Bishop, J.; Cartus, O.; Cormier, T.; Walker, W. S.; Santoro, M.

    2011-12-01

    The availability of several national remote sensing datasets with 30 m resolution for ca. year 2000, i.e. the SRTM DEM, the USGS National Elevation Dataset (NED), the National Land Cover Dataset 2001 (NLCD 2001) as well as Landsat ETM+ data compiled by the Multi-Resolution Land Characteristics Consortium (MRLC), represented a unique opportunity to produce a baseline canopy height and aboveground biomass map for the US, the National Biomass and Carbon Dataset, NBCD 2000. Differentiation of the SRTM Elevations and NED allowed the estimation of the SRTM phase scattering center height within the forest canopies, which was found to be a key predictor for the actual canopy height as well as for the aboveground biomass of live woody vegetation. Together with topographic information derived from the DEM, the NLCD maps and the Landsat data, the phase scattering center heights were used as spatial predictor layers in RandomForest for predicting canopy height and biomass. Forest survey data provided by the USDA Forest Service FIA program were available under a national Memorandum of Understanding and served as response variables for model development and validation. The production of the canopy height and biomass maps was done on a mapping zone basis in which the conterminous US was split into 66 ecoregionally distinct mapping zones. A bootstrap validation at different spatial scales resulted in biomass retrieval accuracies in terms of the root mean square error, RMSE, of 55 t/ha (at plot level), 19 t/ha (at hexagon level) and 14 t/ha (at county level). In case of canopy height, the RMSE was 3.8 m at plot level. In a follow-on project, we aim at generating regional datasets of changes in carbon stocks between the years 2000 and 2007 for the Northeastern US. In order to update the NBCD biomass map, ALOS PALSAR FBD data for the years 2007/08 were ordered from ASF. For the biomass retrieval with ALOS PALSAR data, we adopted a fully automated retrieval algorithm, presented in

  13. Great Lakes Ice Cover Classification and Mapping Using Satellite Synthetic Aperture Radar (SAR) Data

    NASA Technical Reports Server (NTRS)

    Nghiem, S.; Leshkevich, G.; Kwok, R.

    1998-01-01

    Owing to the size and extent of the Great Lakes and the variety of ice types features found there, the timely and objective qualities inherent in computer processing of satellite data make it well suited for monitoring and mapping ice cover.

  14. Collaborative community hazard exposure mapping: Distant Early Warning radar sites in Alaska's North Slope

    NASA Astrophysics Data System (ADS)

    Brady, M.

    2015-12-01

    A method to produce hazard exposure maps that are developed in collaboration with local coastal communities is the focus of this research. Typically efforts to map community exposure to climate threats over large areas have limited consideration of local perspectives about associated risks, constraining their utility for local management. This problem is especially acute in remote locations such as the Arctic where there are unique vulnerabilities to coastal threats that can be fully understood only through inclusion of community stakeholders. Through collaboration with community members, this study identifies important coastal assets and places and surveys local perspectives of exposure to climate threats along Alaska's vast North Slope coastline spanning multiple municipalities. To model physical exposure, the study adapts the U.S. Geological Survey's (USGS) coastal vulnerability index (CVI) to the Arctic context by incorporating the effects of open water distance determined by sea ice extent, and assigning CVI values to coastal assets and places according to direction and proximity. The study found that in addition to concerns about exposed municipal and industrial assets, North Slope communities viewed exposure of traditional activity sites as presenting a particular risk for communities. Highly exposed legacy Cold War Distant Early Warning Line sites are of particular concern with impacts ranging from financial risk to contamination of sensitive coastal marine environments. This research demonstrates a method to collaboratively map community exposure to coastal climate threats to better understand local risks and produce locally usable exposure maps.

  15. Integrated Range-Doppler Map and Extended Target Classification with Adaptive Waveform for Cognitive Radar

    DTIC Science & Technology

    2014-12-01

    wideband waveform. 14. SUBJECT TERMS waveform design, eigen waveform, ambiguity function, target identification , target detection , range Doppler map...are also interested in identification of extended targets . And finally, the third objective (which utilizes the results of the first two) is to...design an integrated scheme for the combined problem of range-Doppler location/ detection with extended target type identification with the use of a

  16. Mapping Spatial Moisture Content of Unsaturated Agricultural Soils with Ground-Penetrating Radar

    NASA Astrophysics Data System (ADS)

    Shamir, O.; Goldshleger, N.; Basson, U.; Reshef, M.

    2016-06-01

    Soil subsurface moisture content, especially in the root zone, is important for evaluation the influence of soil moisture to agricultural crops. Conservative monitoring by point-measurement methods is time-consuming and expensive. In this paper we represent an active remote-sensing tool for subsurface spatial imaging and analysis of electromagnetic physical properties, mostly water content, by ground-penetrating radar (GPR) reflection. Combined with laboratory methods, this technique enables real-time and highly accurate evaluations of soils' physical qualities in the field. To calculate subsurface moisture content, a model based on the soil texture, porosity, saturation, organic matter and effective electrical conductivity is required. We developed an innovative method that make it possible measures spatial subsurface moisture content up to a depth of 1.5 m in agricultural soils and applied it to two different unsaturated soil types from agricultural fields in Israel: loess soil type (Calcic haploxeralf), common in rural areas of southern Israel with about 30% clay, 30% silt and 40% sand, and hamra soil type (Typic rhodoxeralf), common in rural areas of central Israel with about 10% clay, 5% silt and 85% sand. Combined field and laboratory measurements and model development gave efficient determinations of spatial moisture content in these fields. The environmentally friendly GPR system enabled non-destructive testing. The developed method for measuring moisture content in the laboratory enabled highly accurate interpretation and physical computing. Spatial soil moisture content to 1.5 m depth was determined with 1-5% accuracy, making our method useful for the design of irrigation plans for different interfaces.

  17. Radar monitoring of hydrology in Maryland's forested coastal plain wetlands: Implications for predicted climate change and improved mapping

    NASA Astrophysics Data System (ADS)

    Weiner Lang, Megan

    Wetlands provide important services to society but Mid-Atlantic wetlands are at high risk for loss, with forested wetlands being especially vulnerable. Hydrology (flooding and soil moisture) controls wetland function and extent but it may be altered due to changes in climate and anthropogenic influence. Wetland hydrology must better understood in order to predict and mitigate the impact of these changes. Broad-scale forested wetland hydrology is difficult to monitor using ground-based and traditional remote sensing methods. C-band synthetic aperture radar (SAR) data could improve the capability to monitor forested wetland hydrology but the abilities and limitations of these data need further investigation. This study examined: (1) the link between climate and wetland hydrology; (2) the ability of ENVISAT SAR (C-HH and C-VV) data to monitor inundation and soil moisture in forested wetlands; (3) limitations inherent to C-band data (incidence angle, polarization, and phenology) when monitoring forested wetland hydrology; and (4) the accuracy of forested wetland maps produced using SAR data. The study was primarily conducted near the Patuxent River in Maryland but the influence of incidence angle was considered along the Roanoke River in North Carolina. This study showed: (1) climate was highly correlated with wetland inundation; (2) significant differences in C-VV and C-HH backscatter existed between forested areas of varying hydrology (uplands and wetlands) throughout the year; (3) C-HH backscatter was better correlated to hydrology than C-VV backscatter; (4) correlations were stronger during the leaf-off season; (5) the difference in backscatter between flooded and non-flooded areas did not sharply decline with incidence angle, as predicted; and (6) maps produced using SAR data had relatively high accuracy levels. Based on these findings, I concluded that hydrology is influenced by climate at the study site, and C-HH data should be able to monitor changes in

  18. High-resolution mapping of soil moisture at the field scale using ground-penetrating radar for improving remote sensing data products

    NASA Astrophysics Data System (ADS)

    Lambot, Sébastien; Mahmoudzadeh, Mohammad Reza; Phuong Tran, Anh; Nottebaere, Martijn; Leonard, Aline; Defourny, Pierre; Neyt, Xavier

    2014-05-01

    Characterizing the spatiotemporal distribution of soil moisture at various scales is essential in agricultural, hydrological, meteorological, and climatological research and applications. Soil moisture determines the boundary condition between the soil and the atmosphere and governs key processes of the hydrological cycle such as infiltration, runoff, root water uptake, evaporation, as well as energy exchanges between the Earth's surface and the atmosphere. In that respect, ground-penetrating radar (GPR) is of particular interest for field-scale soil moisture mapping as soil moisture is highly correlated to its permittivity, which controls radar wave propagation in the soil. Yet, accurate determination of the electrical properties of a medium using GPR requires full-wave inverse modeling, which has remained a major challenge in applied geophysics for many years. We present a new near-field radar modeling approach for wave propagation in layered media. Radar antennas are modeled using an equivalent set of infinitesimal electric dipoles and characteristic, frequency-dependent, global reflection and transmission coefficients. These coefficients determine wave propagation between the radar reference plane, point sources, and field points. The interactions between the antenna and the soil are inherently accounted for. The fields are calculated using three-dimensional Green's functions. We validated the model using both time and frequency domain radars. The radars were mounted on a quad and controlled by a computer for real-time radar and dGPS data acquisition. Several fields were investigated and time-lapse measurements were performed on some of them to analyze temporal stability in soil moisture patterns and the repeatability of the measurements. The results were compared to ground-truths. The proposed technique is presently being applied to improve space-borne remote sensing data products for soil moisture by providing high-resolution observational information that

  19. Correlated Lightning Mapping Array (LMA) and Radar Observations of the Initial Stages of Florida Triggered Lightning Discharges

    NASA Technical Reports Server (NTRS)

    Hill, J. D.; Pilkey, J.; Uman, M, A.; Jordan, D. M.; Biggerstaff, M. I.; Rison, W.; Blakeslee, R.

    2012-01-01

    We characterize the geometrical and electrical characteristics of the initial stages of nine Florida triggered lightning discharges using a Lightning Mapping Array (LMA), a C-band SMART radar, and measured channel-base currents. We determine initial channel and subsequent branch lengths, average initial channel and branch propagation speeds, and channel-base current at the time of each branch initiation. The channel-base current is found to not change significantly when branching occurs, an unexpected result. The initial stage of Florida triggered lightning typically transitions from vertical to horizontal propagation at altitudes of 3-6 km, near the typical 0 C level of 4-5 km and several kilometers below the expected center of the negative cloud-charge region at 7-8 km. The data presented potentially provide information on thunderstorm electrical and hydrometeor structure and discharge propagation physics. LMA source locations were obtained from VHF sources of positive impulsive currents as small as 10 A, in contrast to expectations found in the literature.

  20. An Ultra-Wideband, Microwave Radar for Measuring Snow Thickness on Sea Ice and Mapping Near-Surface Internal Layers in Polar Firn

    NASA Technical Reports Server (NTRS)

    Panzer, Ben; Gomez-Garcia, Daniel; Leuschen, Carl; Paden, John; Rodriguez-Morales, Fernando; Patel, Azsa; Markus, Thorsten; Holt, Benjamin; Gogineni, Prasad

    2013-01-01

    Sea ice is generally covered with snow, which can vary in thickness from a few centimeters to >1 m. Snow cover acts as a thermal insulator modulating the heat exchange between the ocean and the atmosphere, and it impacts sea-ice growth rates and overall thickness, a key indicator of climate change in polar regions. Snow depth is required to estimate sea-ice thickness using freeboard measurements made with satellite altimeters. The snow cover also acts as a mechanical load that depresses ice freeboard (snow and ice above sea level). Freeboard depression can result in flooding of the snow/ice interface and the formation of a thick slush layer, particularly in the Antarctic sea-ice cover. The Center for Remote Sensing of Ice Sheets (CReSIS) has developed an ultra-wideband, microwave radar capable of operation on long-endurance aircraft to characterize the thickness of snow over sea ice. The low-power, 100mW signal is swept from 2 to 8GHz allowing the air/snow and snow/ ice interfaces to be mapped with 5 c range resolution in snow; this is an improvement over the original system that worked from 2 to 6.5 GHz. From 2009 to 2012, CReSIS successfully operated the radar on the NASA P-3B and DC-8 aircraft to collect data on snow-covered sea ice in the Arctic and Antarctic for NASA Operation IceBridge. The radar was found capable of snow depth retrievals ranging from 10cm to >1 m. We also demonstrated that this radar can be used to map near-surface internal layers in polar firn with fine range resolution. Here we describe the instrument design, characteristics and performance of the radar.

  1. Mapping Upper Amazon Palm Swamps with Spaceborne L-band Synthetic Aperture Radar

    NASA Astrophysics Data System (ADS)

    Pinto, N.; McDonald, K. C.; Podest, E.; Schroeder, R.; Zimmermann, R.; Horna, V.

    2010-12-01

    Palm swamp ecosystems are widespread in the Amazon basin, forming where seasonal flooding is moderate and surface inundation persists. Recent studies suggest that palm swamps have a disproportional role on tropical biogeochemistry: the combination of persistently saturated soils, warm temperatures, and low oxygen soils can support significant land-atmosphere methane flux. Potential impacts of climate change on these ecosystems include changes in temperature and precipitation regimes that influence primary productivity and flood extent significantly, potentially reversing net land-atmosphere carbon exchanges regionally. Data acquired from Earth-orbiting satellites provides the opportunity to characterize vegetation structure and monitor surface inundation independently of cloud cover. Building on efforts under our NASA MEaSUREs project for assembly of a global-scale Earth System Data Record (ESDR) of inundated wetlands, we develop and evaluate a systematic approach to map the distribution and composition of palm swamps in the upper Amazon using data sets from JAXA’s Advanced Land Observing Satellite (ALOS) Phased Array L-Band SAR (PALSAR). Our input dataset consists of HH backscatter images acquired in 2007 and 2009. Ground measurements for training were obtained from a study site near Loreto, Peru (4.43S 75.34W) containing the palm species Mauritia flexuosa. The ALOS PALSAR images are first averaged temporally and spatially. We then develop ancillary data layers of flood extent, distance from open water, and SAR image texture. The PALSAR data and derived ancillary layers are combined with MODIS Vegetation Indices and SRTM elevation and input in a classification framework. Since palm swamps are found in persistently flooded areas, we evaluate the potential of identifying and mapping these ecosystems using multi-temporal SAR-based flood extent maps. We conclude by comparing the performance between a decision-tree supervised vs. unsupervised approach and by

  2. Mapping Structural Elements in Volcanic Terrain Using Multiple Frequencies and Polarimetric Ground Penetrating Radar: Analogy to the Martian Case

    NASA Astrophysics Data System (ADS)

    Heggy, E.; Clifford, S. M.; Hughes, S. S.

    2007-08-01

    Volcanic terrains are among the most prevalent on Mars and several planetary environments, their structural and stratigraphical investigation by GPR providing a powerful tool for understanding the mechanisms and chronological sequence that resulted in their formation. For this reason, a broadband (0.5 - 1.5 GHz) GPR was selected as one of the primary instruments for the European Space Agency's ExoMars rover that will be sent to Mars in 2013-2015. As part of the effort to evaluate the potential of this technique, we carried out a parametric study of several features at Craters of the Moon (COM) National Monument in Idaho (USA). This area, which includes expansive lave fields and volcanic constructs, is a hyper-arid environment with an average annual precipitation of less than 50 mm. It also displays considerable geochemical and geomorphological similarity to a variety of volcanic regions on Mars. Among the examples we investigated were a large cinder cone (Inferno Cone) and surrounding smooth- and rough-surfaced basaltic lava flows. We conducted multiple frequency 270-, 500- and 900-MHz GPR surveys, with both VV and HH polarizations, in both orthogonal and grid form in order to perform a three dimensional mapping of the consolidated core of the cinder cone beneath a thick layer (1-20 m) of tephra that accumulated as a result of different eruptive events. Analysis of the resulting data indicates maximum sounding depths of 13 m deep at 270 MHz, 8 m at 500 MHz and 5 m at 900 MHz in the unconsolidated tephra. Our gridded profiles show that the tephra distribution over the consolidated core is asymmetric, the eastern side being covered by thicker deposits than elsewhere. Our preliminary results also suggest the potential presence of a small spatter cone beneath the eastern flank of the cone. A similar approach was used to investigate the Blue Dragon basaltic lava field located to the south of Inferno Cone. The observed penetration depths were an order of magnitude

  3. Mapping Structural Elements in Volcanic Terrain Using Multiple Frequencies and Polarimetric Ground Penetrating Radar: Analogy to the Martian Case

    NASA Astrophysics Data System (ADS)

    Heggy, E.; Clifford, S. M.; Herique, A.; Kofman, W.; Hughes, S. S.

    2007-08-01

    Volcanic terrains are among the most prevalent on Mars and several planetary environments, their structural and stratigraphical investigation by GPR providing a powerful tool for understanding the mechanisms and chronological sequence that resulted in their formation. For this reason, a broadband (0.5 - 1.5 GHz) GPR was selected as one of the primary instruments for the European Space Agency's ExoMars rover that will be sent to Mars in 2013-2015. As part of the effort to evaluate the potential of this technique, we carried out a parametric study of several features at Craters of the Moon (COM) National Monument in Idaho (USA). This area, which includes expansive lave fields and volcanic constructs, is a hyper-arid environment with an average annual precipitation of less than _50 mm. It also displays considerable geochemical and geomorphological similarity to a variety of volcanic regions on Mars. Among the examples we investigated were a large cinder cone (Inferno Cone) and surrounding smooth- and rough-surfaced basaltic lava flows. We conducted multiple frequency 270-, 500- and 900-MHz GPR surveys, with both VV and HH polarizations, in both orthogonal and grid form in order to perform a three dimensional mapping of the consolidated core of the cinder cone beneath a thick layer (1-20 m) of tephra that accumulated as a result of different eruptive events. Analysis of the resulting data indicates maximum sounding depths of _13 m deep at 270 MHz, 8 m at 500 MHz and 5 m at 900 MHz in the unconsolidated tephra. Our gridded profiles show that the tephra distribution over the consolidated core is asymmetric, the eastern side being covered by thicker deposits than elsewhere. Our preliminary results also suggest the potential presence of a small spatter cone beneath the eastern flank of the cone. A similar approach was used to investigate the Blue Dragon basaltic lava field located to the south of Inferno Cone. The observed penetration depths were an order of magnitude

  4. Mapping and Monitoring Boreal Wetlands within the NEESPI Domain Using Spaceborne Synthetic Aperture Radar for Assessing Carbon Release

    NASA Astrophysics Data System (ADS)

    Podest, E.; McDonald, K. C.; Schroeder, R.; Bohn, T. J.; Lettenmaier, D. P.

    2009-12-01

    Carbon and methane emissions from wetlands and lakes can have a large impact on global climate. These ecosystems are dominant features in the northern high latitudes hence the importance of assessing their spatial and temporal extent to improve upon global net carbon exchange estimates. Spaceborne synthetic aperture radar (SAR) is an effective tool for this purpose since large inaccessible areas can be monitored on a temporal basis regardless of atmospheric conditions or solar illumination and it is sensitive to vegetation and standing water. We employ multi-temporal PALSAR data (L-band, 30 m resolution, HH and HV-polarizations) and combined QuikSCAT and AMSR-E in this study to map wetland distribution and inundation state within sub-regions of the NEESPI domain. These products are then used within a carbon modeling framework. Multi-temporal PALSAR data spanning the beginning of the seasonal non-frozen period through the end of summer has been assembled over selected hydrologic basins within the NEESPI domain. A decision tree classification approach is then used to classify the radar data. Supplementary data layers are used within the classifier in order to support generation of the results. These data layers include Landsat imagery, a DEM, a proximity to water data layer, and image texture. The classification results depicting wetland extent are used to assess bi-weekly landscape inundation products derived from coarse resolution (~25 km) AMSR-E and QuikSCAT. These products will provide information on wetland extent and inundation dynamics on a bi-weekly basis. The coarse and high-resolution products are then used to calibrate and validate a carbon-modeling framework. Examples of how the remote sensing products are used to calibrate and validate the modeling framework will be presented as well. This work was carried out at the Jet Propulsion Laboratory, California Institute of Technology and at the University of Washington under contract with the National

  5. Mapping tropical forest biomass with radar and spaceborne LiDAR in Lopé National Park, Gabon: overcoming problems of high biomass and persistent cloud

    NASA Astrophysics Data System (ADS)

    Mitchard, E. T. A.; Saatchi, S. S.; White, L. J. T.; Abernethy, K. A.; Jeffery, K. J.; Lewis, S. L.; Collins, M.; Lefsky, M. A.; Leal, M. E.; Woodhouse, I. H.; Meir, P.

    2012-01-01

    Spatially-explicit maps of aboveground biomass are essential for calculating the losses and gains in forest carbon at a regional to national level. The production of such maps across wide areas will become increasingly necessary as international efforts to protect primary forests, such as the REDD+ (Reducing Emissions from Deforestation and forest Degradation) mechanism, come into effect, alongside their use for management and research more generally. However, mapping biomass over high-biomass tropical forest is challenging as (1) direct regressions with optical and radar data saturate, (2) much of the tropics is persistently cloud-covered, reducing the availability of optical data, (3) many regions include steep topography, making the use of radar data complex, (5) while LiDAR data does not suffer from saturation, expensive aircraft-derived data are necessary for complete coverage. We present a solution to the problems, using a combination of terrain-corrected L-band radar data (ALOS PALSAR), spaceborne LiDAR data (ICESat GLAS) and ground-based data. We map Gabon's Lopé National Park (5000 km2) because it includes a range of vegetation types from savanna to closed-canopy tropical forest, is topographically complex, has no recent contiguous cloud-free high-resolution optical data, and the dense forest is above the saturation point for radar. Our 100 m resolution biomass map is derived from fusing spaceborne LiDAR (7142 ICESat GLAS footprints), 96 ground-based plots (average size 0.8 ha) and an unsupervised classification of terrain-corrected ALOS PALSAR radar data, from which we derive the aboveground biomass stocks of the park to be 78 Tg C (173 Mg C ha-1). This value is consistent with our field data average of 181 Mg C ha-1, from the field plots measured in 2009 covering a total of 78 ha, and which are independent as they were not used for the GLAS-biomass estimation. We estimate an uncertainty of ±25% on our carbon stock value for the park. This error term

  6. Middle Atmosphere Program. Handbook for MAP. Volume 14: URSI/SCOSTEP Workshop on Technical Aspects of MST Radar

    NASA Technical Reports Server (NTRS)

    Bowhill, S. A. (Editor); Edwards, B. (Editor)

    1984-01-01

    Various topics relative to middle atmosphere research were discussed. meteorological and aeronomical requirements for mesosphere-stratosphere-troposphere (MST) radar networks, general circulation of the middle atmosphere, the interpretation of radar returns from clear air, spaced antenna and Doppler techniques for velocity measurement, and techniques for the study of gravity waves and turbulence are among the topics discussed.

  7. Application of SEASAT-1 Synthetic Aperture Radar (SAR) data to enhance and detect geological lineaments and to assist LANDSAT landcover classification mapping. [Appalachian Region, West Virginia

    NASA Technical Reports Server (NTRS)

    Sekhon, R.

    1981-01-01

    Digital SEASAT-1 synthetic aperture radar (SAR) data were used to enhance linear features to extract geologically significant lineaments in the Appalachian region. Comparison of Lineaments thus mapped with an existing lineament map based on LANDSAT MSS images shows that appropriately processed SEASAT-1 SAR data can significantly improve the detection of lineaments. Merge MSS and SAR data sets were more useful fo lineament detection and landcover classification than LANDSAT or SEASAT data alone. About 20 percent of the lineaments plotted from the SEASAT SAR image did not appear on the LANDSAT image. About 6 percent of minor lineaments or parts of lineaments present in the LANDSAT map were missing from the SEASAT map. Improvement in the landcover classification (acreage and spatial estimation accuracy) was attained by using MSS-SAR merged data. The aerial estimation of residential/built-up and forest categories was improved. Accuracy in estimating the agricultural and water categories was slightly reduced.

  8. Advances in 3D soil mapping and water content estimation using multi-channel ground-penetrating radar

    NASA Astrophysics Data System (ADS)

    Moysey, S. M.

    2011-12-01

    Multi-channel ground-penetrating radar systems have recently become widely available, thereby opening new possibilities for shallow imaging of the subsurface. One advantage of these systems is that they can significantly reduce survey times by simultaneously collecting multiple lines of GPR reflection data. As a result, it is becoming more practical to complete 3D surveys - particularly in situations where the subsurface undergoes rapid changes, e.g., when monitoring infiltration and redistribution of water in soils. While 3D and 4D surveys can provide a degree of clarity that significantly improves interpretation of the subsurface, an even more powerful feature of the new multi-channel systems for hydrologists is their ability to collect data using multiple antenna offsets. Central mid-point (CMP) surveys have been widely used to estimate radar wave velocities, which can be related to water contents, by sequentially increasing the distance, i.e., offset, between the source and receiver antennas. This process is highly labor intensive using single-channel systems and therefore such surveys are often only performed at a few locations at any given site. In contrast, with multi-channel GPR systems it is possible to physically arrange an array of antennas at different offsets, such that a CMP-style survey is performed at every point along a radar transect. It is then possible to process this data to obtain detailed maps of wave velocity with a horizontal resolution on the order of centimeters. In this talk I review concepts underlying multi-channel GPR imaging with an emphasis on multi-offset profiling for water content estimation. Numerical simulations are used to provide examples that illustrate situations where multi-offset GPR profiling is likely to be successful, with an emphasis on considering how issues like noise, soil heterogeneity, vertical variations in water content and weak reflection returns affect algorithms for automated analysis of the data. Overall

  9. Mapping Exposed and Buried Lava Flows Using Synthetic Aperture and Ground-Penetrating Radar in Craters of the Moon Lava Field

    NASA Astrophysics Data System (ADS)

    Khan, S. D.; Heggy, E.; Fernandez, J.

    2007-10-01

    The Craters of the Moon (COM) lava field in central Idaho has a multiple eruptive history. Burial of older flows by younger eruptive events has resulted in complex surface geomorphology and subsurface stratigraphy. For the older eruptive periods, the locations of source vents and the extension of lava flows are either speculative or unknown, as they are buried under earlier pyroclastistics. In this study, we used surface and subsurface backscatter characteristics of the P- and L-band polarimetric Airborne Synthetic Aperture Radar (AIRSAR) data and Ground-Penetrating Radar (GPR) soundings to resolve different exposed and buried lava flows. Our primary objective is to define the most effective polarization and frequency for mapping, resolving, and characterizing different lava types in the volcanic field. Polarimetric analysis of AIRSAR images from COM allows a clear recognition of the aa' and pahoehoe lava types as a result of the variability in their roughness. Our results suggest that the HV cross-polarized, AIRSAR L band is capable of producing a detailed map delineating surface lava with different surface backscattering properties. An accuracy assessment utilizing the geological map of the Inferno Cone area and in situ observations showed a significant reliability of differentiating lava types and mapping the lava flows extension below loose pyroclastics using AIRSAR data. The P-band, results suggest a constrained ability for mapping buried structures up to 3 meters deep under loose and dry cinder and ash deposits, resolving buried fissures, outcrops, and lava flows that were validated with ground-truth GPR surveys. Investigating subsurface stratigraphy with remote sensing and GPR techniques can be applied in other arid locations on Earth and other planets. Analyzing the radar backscattering penetration depth at higher frequencies is valuable for future planetary subsurface exploration missions for telluric planets.

  10. Topical report on subsurface fracture mapping from geothermal wellbores. Phase I. Pulsed radar techniques. Phase II. Conventional logging methods. Phase III. Magnetic borehole ranging

    SciTech Connect

    Hartenbaum, B.A.; Rawson, G.

    1980-09-01

    To advance the state-of-the-art in Hot Dry Rock technology, an evaluation is made of (i) the use of radar to map far-field fractures, (ii) the use of more than twenty different conventional well logging tools to map borehole-fracture intercepts, and (iii) the use of magnetic dipole ranging to determine the relative positions of the injection well and the production well within the fractured zone. It is found that according to calculations, VHF backscatter radar has the potential for mapping fractures within a distance of 50 +- 20 meters from the wellbore. A new technique for improving fracture identification is presented. Analyses of extant data indicate that when used synergistically the (1) caliper, (2) resistivity dipmeter, (3) televiewer, (4) television, (5) impression packer, and (6) acoustic transmission are useful for mapping borehole-fracture intercepts. Improvements in both data interpretation techniques and high temperature operation are required. The surveying of one borehole from another appears feasible at ranges of up to 200 to 500 meters by using a low frequency magnetic field generated by a moderately strong dipole source (a solenoid) located in one borehole, a sensitive B field detector that traverses part of the second borehole, narrow band filtering, and special data inversion techniques.

  11. Planetary radar studies

    NASA Technical Reports Server (NTRS)

    Thompson, T. W.; Cutts, J. A.

    1981-01-01

    A catalog of lunar and radar anomalies was generated to provide a base for comparison with Venusian radar signatures. The relationships between lunar radar anomalies and regolith processes were investigated, and a consortium was formed to compare lunar and Venusian radar images of craters. Time was scheduled at the Arecibo Observatory to use the 430 MHz radar to obtain high resolution radar maps of six areas of the lunar suface. Data from 1978 observations of Mare Serenitas and Plato are being analyzed on a PDP 11/70 computer to construct the computer program library necessary for the eventual reduction of the May 1981 and subsequent data acquisitions. Papers accepted for publication are presented.

  12. Radar Remote Sensing

    NASA Technical Reports Server (NTRS)

    Rosen, Paul A.

    2012-01-01

    This lecture was just a taste of radar remote sensing techniques and applications. Other important areas include Stereo radar grammetry. PolInSAR for volumetric structure mapping. Agricultural monitoring, soil moisture, ice-mapping, etc. The broad range of sensor types, frequencies of observation and availability of sensors have enabled radar sensors to make significant contributions in a wide area of earth and planetary remote sensing sciences. The range of applications, both qualitative and quantitative, continue to expand with each new generation of sensors.

  13. High-resolution Rainfall Mapping in Dallas-Fort Worth (DFW) Urban Network of Radars at Multiple Frequencies

    NASA Astrophysics Data System (ADS)

    Chandra, Chandrasekar V.; Chen*, Haonan

    2015-04-01

    Urban flash flood is one of the most commonly encountered hazardous weather phenomena. Unfortunately, the rapid urbanization has made the densely populated areas even more vulnerable to flood risks. Hence, accurate and timely monitoring of rainfall at high spatiotemporal resolution is critical to severe weather warning and civil defense, especially in urban areas. However, it is still challenging to produce high-resolution products based on the large S-band National Weather Service (NWS) Next-Generation Weather Radar (NEXRAD), due to the sampling limitations and Earth curvature effect. Since 2012, the U.S. National Science Foundation Engineering Research Center (NSF-ERC) for Collaborative Adaptive Sensing of the Atmosphere (CASA) has initiated the development of Dallas-Fort Worth (DFW) radar remote sensing network for urban weather hazards mitigation. The DFW urban radar network consists of a combination of high-resolution X-band radars and a standard NWS NEXRAD radar operating at S-band frequency. High-resolution quantitative precipitation estimation (QPE) is one of the major research goals in the deployment of this urban radar network. It has been shown in the literature that the dual-polarization radar techniques can improve the QPE accuracy over traditional single-polarization radars by rendering more measurements to enhance the data quality, providing more information about rain drop size distribution (DSD), and implying more characteristics of different hydrometeor types. This paper will present the real-time dual-polarization CASA DFW QPE system, which is developed via fusion of observations from both the high-resolution X band radar network and the S-band NWS radar. The specific dual-polarization rainfall algorithms at different frequencies (i.e., S- and X-band) will be described in details. In addition, the fusion methodology combining observations at different temporal resolution will be presented. In order to demonstrate the capability of rainfall

  14. Rapid Damage Mapping for the 2015 M7.8 Gorkha Earthquake using Synthetic Aperture Radar Data from COSMO-SkyMed and ALOS-2 Satellites

    NASA Astrophysics Data System (ADS)

    Yun, S. H.; Hudnut, K. W.; Owen, S. E.; Webb, F.; Simons, M.; Macdonald, A.; Sacco, P.; Gurrola, E. M.; Manipon, G.; Liang, C.; Fielding, E. J.; Milillo, P.; Hua, H.; Coletta, A.

    2015-12-01

    The April 25, 2015 M7.8 Gorkha earthquake caused more than 8,000 fatalities and widespread building damage in central Nepal. Four days after the earthquake, the Italian Space Agency's (ASI's) COSMO-SkyMed Synthetic Aperture Radar (SAR) satellite acquired data over Kathmandu area. Nine days after the earthquake, the Japan Aerospace Exploration Agency's (JAXA's) ALOS-2 SAR satellite covered larger area. Using these radar observations, we rapidly produced damage proxy maps derived from temporal changes in Interferometric SAR (InSAR) coherence. These maps were qualitatively validated through comparison with independent damage analyses by National Geospatial-Intelligence Agency (NGA) and the UNITAR's (United Nations Institute for Training and Research's) Operational Satellite Applications Programme (UNOSAT), and based on our own visual inspection of DigitalGlobe's WorldView optical pre- vs. post-event imagery. Our maps were quickly released to responding agencies and the public, and used for damage assessment, determining inspection/imaging priorities, and reconnaissance fieldwork.

  15. Using Ground Penetration Radar for Imaging and Mapping of Thin, Shallow Tsunami Deposits in Washington, Pacific Northwest United States

    NASA Astrophysics Data System (ADS)

    Cakir, R.; Garrison-Laney, C.; Meng, X.; Butler, Q.; Walsh, T. J.

    2015-12-01

    A tidal marsh at Discovery Bay, on the Strait of Juan de Fuca, has the longest record of tsunami deposition in Washington, with nine described tsunami deposits. One of the youngest continuous deposits Bed 1is likely from the 1700 A.D. M9+ Cascadia Earthquake, based on its stratigraphic position and radiocarbon age. Bed 1 is typically found at a depth of ~ 0.45 m, has a maximum thickness of 8 cm, and is composed grains of silt to fine sand. Ground Penetration Radar (GPR) is useful to study such tsunami deposits, because it can "see" characteristics of the deposits that could be missed in cores or outcrops. Tsunami deposits typically extend over wide areas. GPR imaging can trace a layer over a wide area in the subsurface of a tidal marsh. Correlation of layers between coring or outcrops is often difficult across distances in a marsh. GPR technology allows in situ correlation of potential tsunami deposits in the subsurface. We used GPR to map subsurface images of previously described tsunami deposits in the top 2 m at Discovery Bay. We used MALA 450 MHz antenna and recording unit, and ran the survey during the low tide time range (3-4 hours). After adjusting the soil velocity (dielectric constants) and scan parameters we ran various transects correlated the shallow soil cores in 0-1.5m of the soil column. Tsunami sand layer is relatively distinct among other layers on radargrams. Maximum penetration depth reached was about 2 meters and saltwater effect is dominant at 2 meters and greater depths. In addition to this success, there is also the potential to use GPR to"see" characteristic tsunami deposit features such as draping and infilling of low spots. This imaging could help guide locations to sample with strategic cores or pits. We think that our preliminary results are promising,and plan to use the GPR technology to investigate potential tsunami deposits inPuget Sound and other coastal areas of Washington.

  16. Mapping exposed and buried lava flows using synthetic aperture and ground-penetrating radar in Craters of the Moon lava field

    NASA Astrophysics Data System (ADS)

    Khan, Shuhab D.; Heggy, Essam; Fernandez, Jaime

    2007-11-01

    The Craters of the Moon (COM) lava field has a multiple eruptive history. Burial of older flows has resulted in complex subsurface stratigraphy. For the older eruptive periods, the locations of source vents and the extension of lava flows are either speculative or unknown, because they are buried under more recent pyroclastics. In this study, we used surface and subsurface backscatter characteristics of the P- and L-band polarimetric airborne synthetic aperture radar (AIRSAR) data and ground-penetrating radar (GPR) soundings to resolve different exposed and buried lava flows. Our primary objective is to define the most effective polarization and frequency for mapping, resolving, and characterizing different lava types in the volcanic field. Polarimetric analysis of AIRSAR images from COM allows a clear recognition of the aa and pahoehoe lava types as a result of the variability in their roughness. Our results suggest that the HV cross-polarized, AIRSAR L-band is capable of producing a detailed map delineating surface lava with different surface backscattering properties. An accuracy assessment utilizing the geological map of the Inferno Cone area was performed to quantify the reliability of differentiating lava types and mapping the lava flows extension below loose pyroclastics using AIRSAR data. Results shows an ability of P-band SAR to map buried structures up to 3 meters deep under loose cinder and ash deposits, resolving buried fissures, outcrops, and lava flows that were validated with ground-truth GPR surveys. The techniques used in this study provide a tool to assess volcanic hazards in remote and inaccessible places. Also it could be an aid in the study of other planets and planetary bodies in the solar system.

  17. Application of synthetic aperture radar (SAR) imagery to volcano mapping in the humid tropics: a case study in East Java, Indonesia

    NASA Astrophysics Data System (ADS)

    Carn, Simon A.

    Volcanoes in humid tropical environments are frequently cloud covered, typically densely vegetated and rapidly eroded. These factors complicate field and laboratory studies and even the basic identification of potentially active volcanoes. Numerous previous studies have highlighted the potential value of radar remote sensing for volcanology in equatorial regions. Here, cloud- and vegetation-penetrating LHH-band (λ 24cm) synthetic aperture radar (SAR) data from the Japanese Earth Resources Satellite (JERS-1) are used to investigate persistently active volcanoes and prehistoric calderas in East Java, Indonesia. The LHH-band JERS-1 SAR produces high-spatial-resolution (18m) imagery with relatively high incidence angle that highlights structures and topographic variations at or greater than the wavelength scale while minimising geometrical distortions such as layover and foreshortening. These images, along with Internet browse data derived from the Canadian RADARSAT mission, provide new evidence relating regional tectonics to volcanism throughout East Java. Volcanic events, such as caldera collapse at the Tengger caldera, appear to have been partly controlled by northwest-aligned faults related to intra-arc sedimentary basins. Similar regional controls appear important at historically active Lamongan volcano, which is encircled by numerous flank maars and cinder cones. A previously undocumented pyroclastic sheet and debris avalanche deposit from the Jambangan caldera complex is also manifested in the synoptic radar images. At the currently active Semeru volcano these data permit identification of recent pyroclastic flow and lahar deposits. Radar data therefore offer a valuable tool for mapping and hazard assessment at late Quaternary volcanoes. The criteria developed in the analysis here could be applied to other regions in the humid tropics.

  18. Rapid damage mapping for the 2015 M7.8 Gorkha earthquake using synthetic aperture radar data from COSMO-SkyMed and ALOS-2 satellites

    USGS Publications Warehouse

    Yun, Sang-Ho; Hudnut, Kenneth W.; Owen, Susan; Webb, Frank; Simons, Mark; Sacco, Patrizia; Gurrola, Eric; Manipon, Gerald; Liang, Cunren; Fielding, Eric; Milillo, Pietro; Hua, Hook; Coletta, Alessandro

    2015-01-01

    The 25 April 2015 Mw 7.8 Gorkha earthquake caused more than 8000 fatalities and widespread building damage in central Nepal. The Italian Space Agency’s COSMO–SkyMed Synthetic Aperture Radar (SAR) satellite acquired data over Kathmandu area four days after the earthquake and the Japan Aerospace Exploration Agency’s Advanced Land Observing Satellite-2 SAR satellite for larger area nine days after the mainshock. We used these radar observations and rapidly produced damage proxy maps (DPMs) derived from temporal changes in Interferometric SAR coherence. Our DPMs were qualitatively validated through comparison with independent damage analyses by the National Geospatial-Intelligence Agency and the United Nations Institute for Training and Research’s United Nations Operational Satellite Applications Programme, and based on our own visual inspection of DigitalGlobe’s WorldView optical pre- versus postevent imagery. Our maps were quickly released to responding agencies and the public, and used for damage assessment, determining inspection/imaging priorities, and reconnaissance fieldwork.

  19. Radar and Lidar Radar DEM

    NASA Technical Reports Server (NTRS)

    Liskovich, Diana; Simard, Marc

    2011-01-01

    Using radar and lidar data, the aim is to improve 3D rendering of terrain, including digital elevation models (DEM) and estimates of vegetation height and biomass in a variety of forest types and terrains. The 3D mapping of vegetation structure and the analysis are useful to determine the role of forest in climate change (carbon cycle), in providing habitat and as a provider of socio-economic services. This in turn will lead to potential for development of more effective land-use management. The first part of the project was to characterize the Shuttle Radar Topography Mission DEM error with respect to ICESat/GLAS point estimates of elevation. We investigated potential trends with latitude, canopy height, signal to noise ratio (SNR), number of LiDAR waveform peaks, and maximum peak width. Scatter plots were produced for each variable and were fitted with 1st and 2nd degree polynomials. Higher order trends were visually inspected through filtering with a mean and median filter. We also assessed trends in the DEM error variance. Finally, a map showing how DEM error was geographically distributed globally was created.

  20. Java Radar Analysis Tool

    NASA Technical Reports Server (NTRS)

    Zaczek, Mariusz P.

    2005-01-01

    Java Radar Analysis Tool (JRAT) is a computer program for analyzing two-dimensional (2D) scatter plots derived from radar returns showing pieces of the disintegrating Space Shuttle Columbia. JRAT can also be applied to similar plots representing radar returns showing aviation accidents, and to scatter plots in general. The 2D scatter plots include overhead map views and side altitude views. The superposition of points in these views makes searching difficult. JRAT enables three-dimensional (3D) viewing: by use of a mouse and keyboard, the user can rotate to any desired viewing angle. The 3D view can include overlaid trajectories and search footprints to enhance situational awareness in searching for pieces. JRAT also enables playback: time-tagged radar-return data can be displayed in time order and an animated 3D model can be moved through the scene to show the locations of the Columbia (or other vehicle) at the times of the corresponding radar events. The combination of overlays and playback enables the user to correlate a radar return with a position of the vehicle to determine whether the return is valid. JRAT can optionally filter single radar returns, enabling the user to selectively hide or highlight a desired radar return.

  1. Weather Radar Studies

    DTIC Science & Technology

    1988-03-31

    Reflectivity Core Recognition 68 IV-10 Middle-Level Precursor Recognition 69 IV-l I Early Microburst Hazard Declaration 70 IV-12 Example of Results from...Denver Test Bed 106 V-I Selected Product Types 14 V-2 Encoded Map Size (in ELMs ) for Terminal Map Data Set 119 V-3 Encoded Map Size (in ELMs ) for En...Route Data Sets 119 V-4 Encoded Map Size (in ELMs ) for Terminal Map Data Set 125 xiii WEATHER RADAR STUDIES 1. INTRODUCTION The principal areas of

  2. Late Tertiary and Quaternary river systems of the eastern Sahara as mapped on shuttle radar and LANDSAT images

    NASA Technical Reports Server (NTRS)

    Mccauley, J. F.; Breed, C. S.; Schaber, G. G.

    1985-01-01

    SIR-A pictures of the Eastern Sahara show segments of what are interpreted as relics of once major Tertiary and Quaternary stream valleys. These previously unmapped features have a dark to very dark radar response and are generally concealed below a thin cover of flat to slightly undulating deposits, mostly of eolian origin. In most of the 150 pits and trenches we have studied to date, unconsolidated surface deposits range from a few centimeters to about a meter thick. The SIR-A system was able to "see through" this loose, dry material, to a depth of about a meter or two.

  3. The Stratiform Region of an MCS on 19 June in TELEX 2004 Observed With Polarimetric and Doppler Radars, Electric Field Soundings, and a Lightning Mapping Array

    NASA Astrophysics Data System (ADS)

    Ramig, N.; Macgorman, D.; Rust, D.; Schuur, T.; Bruning, E.; Krehbiel, P.; Rison, W.; Hamlin, T.; Straka, J.; Payne, C.; Apostolakopoulos, I.; Biggerstaff, M. I.; Biermann, N.; Carey, L.

    2005-12-01

    Polarimetric and Doppler radar data, balloon-borne soundings of the electric field, and three-dimensional lightning mapping array data were acquired from a mesoscale convective system (MCS) on 19 June 2004 during the Thunderstorm Electrification and Lightning Experiment (TELEX). A total of 10 partial and complete vertical soundings through the storm were obtained from the flights of four instrumented balloons: two launched in the convective region, one in the transition zone, and one in the stratiform region. Each balloon recorded ascent and descent soundings and the transition zone balloon recorded an additional two partial soundings due to a downdraft. At times, multiple soundings were in progress simultaneously. This study focuses on the stratiform region of the MCS, which was sampled by the last two soundings of balloon three and both soundings of balloon four. A comparison of the electrical structure of the stratiform region of this MCS with that of previously published conceptual models suggests that, during at least part of the MCS's lifetime, its electrical structure was Type A, which is more complex than Type B. The main difference between these classifications is the number of charge regions in the cloud. A one-dimensional analysis with Gauss's law indicates six vertically stacked charge layers that alternated polarity within the stratiform region during balloon four's ascent. The vector electric field pattern verified the 1-D Gauss analysis and showed the electric field structure to be primarily horizontally stratified. The maximum magnitude of the electric field was approximately 105 kV/m. The second stratiform sounding sampled by balloon three began fifty minutes after the first stratiform sounding. It showed a very different electric field profile, consistent with neither Type A nor Type B electrical structure, perhaps because the sounding was far from the front of the MCS. There were only three charge layers as opposed to the four charge layers

  4. Recent advances in radar applications to agriculture

    NASA Technical Reports Server (NTRS)

    Morain, S. A.

    1970-01-01

    A series of remote radar sensing studies are summarized. These efforts comprise geoscience interpretations of such complex phenomena as those manifested in agricultural patterns. Considered are basic remote sensing needs in agriculture and the design and implementation of radar keys in the active microwave region as well as fine resolution radar imagery techniques for agriculture determinations and soil mapping.

  5. High-Resolution Regional Biomass Map of Siberia from Glas, Palsar L-Band Radar and Landsat Vcf Data

    NASA Astrophysics Data System (ADS)

    Sun, G.; Ranson, K.; Montesano, P.; Zhang, Z.; Kharuk, V.

    2015-12-01

    The Arctic-Boreal zone is known be warming at an accelerated rate relative to other biomes. The taiga or boreal forest covers over 16 x106 km2 of Arctic North America, Scandinavia, and Eurasia. A large part of the northern Boreal forests are in Russia's Siberia, as area with recent accelerated climate warming. During the last two decades we have been working on characterization of boreal forests in north-central Siberia using field and satellite measurements. We have published results of circumpolar biomass using field plots, airborne (PALS, ACTM) and spaceborne (GLAS) lidar data with ASTER DEM, LANDSAT and MODIS land cover classification, MODIS burned area and WWF's ecoregion map. Researchers from ESA and Russia have also been working on biomass (or growing stock) mapping in Siberia. For example, they developed a pan-boreal growing stock volume map at 1-kilometer scale using hyper-temporal ENVISAT ASAR ScanSAR backscatter data. Using the annual PALSAR mosaics from 2007 to 2010 growing stock volume maps were retrieved based on a supervised random forest regression approach. This method is being used in the ESA/Russia ZAPAS project for Central Siberia Biomass mapping. Spatially specific biomass maps of this region at higher resolution are desired for carbon cycle and climate change studies. In this study, our work focused on improving resolution ( 50 m) of a biomass map based on PALSAR L-band data and Landsat Vegetation Canopy Fraction products. GLAS data were carefully processed and screened using land cover classification, local slope, and acquisition dates. The biomass at remaining footprints was estimated using a model developed from field measurements at GLAS footprints. The GLAS biomass samples were then aggregated into 1 Mg/ha bins of biomass and mean VCF and PALSAR backscatter and textures were calculated for each of these biomass bins. The resulted biomass/signature data was used to train a random forest model for biomass mapping of entire region from 50o

  6. Radar principles

    NASA Technical Reports Server (NTRS)

    Sato, Toru

    1989-01-01

    Discussed here is a kind of radar called atmospheric radar, which has as its target clear air echoes from the earth's atmosphere produced by fluctuations of the atmospheric index of refraction. Topics reviewed include the vertical structure of the atmosphere, the radio refractive index and its fluctuations, the radar equation (a relation between transmitted and received power), radar equations for distributed targets and spectral echoes, near field correction, pulsed waveforms, the Doppler principle, and velocity field measurements.

  7. A Comparative Study of the Ionospheric TEC Measurements Using Global Ionospheric Maps of GPS, TOPEX Radar and the Bent Model

    NASA Technical Reports Server (NTRS)

    Ho, C.; Wilson, B.; Mannucci, A.; Lindqwister, U.; Yuan, D.

    1997-01-01

    Global ionospheric mapping (GIM) is a new, emerging technique for determining global ionospheric TEC (total electron content) based on measurements from a worldwide network of Global Positioning System (GPS) receivers.

  8. Monitoring seasonal state and mapping species in Alaskan taiga using imaging radar as input to CO[sub 2] flux models

    SciTech Connect

    Way, J.B.; Rignot, E.; McDonald, K.; Adams, P.; Viereck, L. Institute of Northern Forestry, Fairbanks, AK )

    1993-06-01

    Changes in the seasonal CO[sub 2] flux of the boreal forests may result from increased atmospheric CO[sub 2] concentrations and associated atmospheric warming. To monitor this potential change, a combination of remote sensing information and ecophysiological models are required. In this paper we address the use of synthetic aperture radar (SAR) data to provide some of the input to the ecophysiological models: forest type, freeze/thaw state which limits the growing season for conifers, and leaf on/off state which limits the growing season for deciduous species. AIRSAR data collected in March 1988 during an early thaw event and May 1991 during spring breakup are used to generate species maps and to determine the sensitivity of SAR to canopy freeze/thaw transitions. These data are also used to validate a microwave scattering model which is then used to determine the sensitivity of SAR to leaf on/off and soil freeze/thaw transitions. Finally, a CO[sub 2] flux algorithm which utilizes SAR data and an ecophysiological model to estimate CO[sub 2] flux is presented. CO[sub 2] flux maps are generated from which areal estimates of CO[sub 2] flux are derived. This work was carried out at the Jet Propulsion Laboratory under contract to the NASA.

  9. (abstract) Monitoring Seasonal State and Mapping Species in Alaskan Taiga Using Imaging Radar as Input to CO(sub 2) Flux Models

    NASA Technical Reports Server (NTRS)

    Way, J. B.; Rignot, E.; McDonald, K.; Adams, P.; Viereck, L.

    1993-01-01

    Changes in the seasonal CO(sub 2) flux of the boreal forests may result from increased atmospheric CO(sub 2) concentrations and associated atmospheric warming. To monitor this potential change, a combination of remote sensing information and ecophysiological models are required. In this paper we address the use of synthetic aperture radar (SAR) data to provide some of the input to the ecophysiological models: forest type, freeze/thaw state which limits the growing season for conifers, and leaf on/off state which limits the growing season for deciduous species. AIRSAR data collected in March 1988 during an early thaw event and May 1991 during spring breakup are used to generate species maps and to determine the sensitivity of SAR to canopy freeze/thaw transitions. These data are also used to validate a microwave scattering model which is then used to determine the sensitivity of SAR to leaf on/off and soil freeze/thaw transitions. Finally, a CO(sub 2) flux algorithm which utilizes SAR data and an ecophysiological model to estimate CO(sub 2) flux is presented. CO(sub 2) flux maps are generated from which areal estimates of CO(sub 2) flux are derived.

  10. Shuttle Imaging Radar - Geologic applications

    NASA Technical Reports Server (NTRS)

    Macdonald, H.; Bridges, L.; Waite, W.; Kaupp, V.

    1982-01-01

    The Space Shuttle, on its second flight (November 12, 1981), carried the first science and applications payload which provided an early demonstration of Shuttle's research capabilities. One of the experiments, the Shuttle Imaging Radar-A (SIR-A), had as a prime objective to evaluate the capability of spaceborne imaging radars as a tool for geologic exploration. The results of the experiment will help determine the value of using the combination of space radar and Landsat imagery for improved geologic analysis and mapping. Preliminary analysis of the Shuttle radar imagery with Seasat and Landsat imagery from similar areas provides evidence that spaceborne radars can significantly complement Landsat interpretation, and vastly improve geologic reconnaissance mapping in those areas of the world that are relatively unmapped because of perpetual cloud cover.

  11. Road Network Conflation Based on Radar Tracks

    DTIC Science & Technology

    2014-04-01

    synthetic aperture radar (SAR) images, but this process is extremely slow and laborious. Automatic transformation of images into digital road maps is...Likelihood Estimator NIMA National Imagery and Mapping Agency SAR Synthetic Aperture Radar STAP Space-Time Adaptive Processing USGS United States Geological Survey 27 Approved for Public Release; Distribution Unlimited. ...ROAD NETWORK CONFLATION BASED ON RADAR TRACKS SYRACUSE UNIVERSITY APRIL 2014 FINAL TECHNICAL REPORT APPROVED FOR PUBLIC

  12. Oil source-fingerprinting in support of polarimetric radar mapping of Macondo-252 oil in Gulf Coast marshes.

    PubMed

    Ramsey, Elijah; Meyer, Buffy M; Rangoonwala, Amina; Overton, Edward; Jones, Cathleen E; Bannister, Terri

    2014-12-15

    Polarimetric synthetic aperture radar (PolSAR) data exhibited dramatic, spatially extensive changes from June 2009 to June 2010 in Barataria Bay, Louisiana. To determine whether these changes were associated with the Deepwater Horizon (DWH) oil spill, twenty-nine sediment samples were collected in 2011 from shoreline and nearshore-interior coastal marsh locations where oil was not observed visually or with optical sensors during the spill. Oil source-fingerprinting and polytopic vector analysis were used to link DWH oil to PolSAR changes. Our results prove that DWH oil extended beyond shorelines and confirm the association between presence of DWH oil and PolSAR change. These results show that the DWH oil spill probably affected much more of the southeastern Louisiana marshland than originally concluded from ground and aerial surveys and verify that PolSAR is a powerful tool for tracking oil intrusion into marshes with high probability even where contamination is not visible from above the canopy.

  13. Method for detecting surface motions and mapping small terrestrial or planetary surface deformations with synthetic aperture radar

    NASA Technical Reports Server (NTRS)

    Gabriel, Andrew K. (Inventor); Goldstein, Richard M. (Inventor); Zebker, Howard A. (Inventor)

    1990-01-01

    A technique based on synthetic aperture radar (SAR) interferometry is used to measure very small (1 cm or less) surface deformations with good resolution (10 m) over large areas (50 km). It can be used for accurate measurements of many geophysical phenomena, including swelling and buckling in fault zones, residual, vertical and lateral displacements from seismic events, and prevolcanic swelling. Two SAR images are made of a scene by two spaced antennas and a difference interferogram of the scene is made. After unwrapping phases of pixels of the difference interferogram, surface motion or deformation changes of the surface are observed. A second interferogram of the same scene is made from a different pair of images, at least one of which is made after some elapsed time. The second interferogram is then compared with the first interferogram to detect changes in line of sight position of pixels. By resolving line of sight observations into their vector components in other sets of interferograms along at least one other direction, lateral motions may be recovered in their entirety. Since in general, the SAR images are made from flight tracks that are separated, it is not possible to distinguish surface changes from the parallax caused by topography. However, a third image may be used to remove the topography and leave only the surface changes.

  14. Oil source-fingerprinting in support of polarimetric radar mapping of Macondo-252 oil in Gulf Coast marshes

    USGS Publications Warehouse

    Ramsey III, Elijah W.; Meyer, Buffy M.; Rangoonwala, Amina; Overton, Edward; Jones, Cathleen E.; Bannister, Terri

    2014-01-01

    Polarimetric synthetic aperture radar (PolSAR) data exhibited dramatic, spatially extensive changes from June 2009 to June 2010 in Barataria Bay, Louisiana. To determine whether these changes were associated with the Deepwater Horizon (DWH) oil spill, twenty-nine sediment samples were collected in 2011 from shoreline and nearshore–interior coastal marsh locations where oil was not observed visually or with optical sensors during the spill. Oil source-fingerprinting and polytopic vector analysis were used to link DWH oil to PolSAR changes. Our results prove that DWH oil extended beyond shorelines and confirm the association between presence of DWH oil and PolSAR change. These results show that the DWH oil spill probably affected much more of the southeastern Louisiana marshland than originally concluded from ground and aerial surveys and verify that PolSAR is a powerful tool for tracking oil intrusion into marshes with high probability even where contamination is not visible from above the canopy.

  15. Savannah woody structure modelling and mapping using multi-frequency (X-, C- and L-band) Synthetic Aperture Radar data

    NASA Astrophysics Data System (ADS)

    Naidoo, Laven; Mathieu, Renaud; Main, Russell; Kleynhans, Waldo; Wessels, Konrad; Asner, Gregory; Leblon, Brigitte

    2015-07-01

    Structural parameters of the woody component in African savannahs provide estimates of carbon stocks that are vital to the understanding of fuelwood reserves, which is the primary source of energy for 90% of households in South Africa (80% in Sub-Saharan Africa) and are at risk of over utilisation. The woody component can be characterised by various quantifiable woody structural parameters, such as tree cover, tree height, above ground biomass (AGB) or canopy volume, each been useful for different purposes. In contrast to the limited spatial coverage of ground-based approaches, remote sensing has the ability to sense the high spatio-temporal variability of e.g. woody canopy height, cover and biomass, as well as species diversity and phenological status - a defining but challenging set of characteristics typical of African savannahs. Active remote sensing systems (e.g. Light Detection and Ranging - LiDAR; Synthetic Aperture Radar - SAR), on the other hand, may be more effective in quantifying the savannah woody component because of their ability to sense within-canopy properties of the vegetation and its insensitivity to atmosphere and clouds and shadows. Additionally, the various components of a particular target's structure can be sensed differently with SAR depending on the frequency or wavelength of the sensor being utilised. This study sought to test and compare the accuracy of modelling, in a Random Forest machine learning environment, woody above ground biomass (AGB), canopy cover (CC) and total canopy volume (TCV) in South African savannahs using a combination of X-band (TerraSAR-X), C-band (RADARSAT-2) and L-band (ALOS PALSAR) radar datasets. Training and validation data were derived from airborne LiDAR data to evaluate the SAR modelling accuracies. It was concluded that the L-band SAR frequency was more effective in the modelling of the CC (coefficient of determination or R2 of 0.77), TCV (R2 of 0.79) and AGB (R2 of 0.78) metrics in Southern African

  16. Planetary Radar

    NASA Technical Reports Server (NTRS)

    Neish, Catherine D.; Carter, Lynn M.

    2015-01-01

    This chapter describes the principles of planetary radar, and the primary scientific discoveries that have been made using this technique. The chapter starts by describing the different types of radar systems and how they are used to acquire images and accurate topography of planetary surfaces and probe their subsurface structure. It then explains how these products can be used to understand the properties of the target being investigated. Several examples of discoveries made with planetary radar are then summarized, covering solar system objects from Mercury to Saturn. Finally, opportunities for future discoveries in planetary radar are outlined and discussed.

  17. SETTLEMENT AREA MAPPING USING OPTICAL AND SYNTHETIC APERTURE RADAR (SAR) REMOTE SENSING IMAGERY TO SUPPORT TSUNAMI RISK ASSESSMENT

    NASA Astrophysics Data System (ADS)

    Khomarudin, R.; Strunz, G.; Ludwig, R.; Post, J.; Zosseder, K.; Esch, T.; Indrajit, A.; Khomarudin, R.

    2009-12-01

    In Indonesia more than 60% of the population and more than 80% of the industrial areas are located in the coastal regions. Many of the development activities take place in the coastal areas such as fisheries, agriculture, industry, transportation, tourism, urban development, that are particularly vulnerable to natural disasters. Indonesia is one of the most vulnerable countries on the world with respect to the tsunami threat. In the framework of the GITEWS (German Indonesian Tsunami Early Warning System) project a comprehensive risk assessment is being performed. To mitigate and decrease the loss of lives caused by tsunami, the information on people activities and settlement area is important. Remote sensing techniques can be applied to map settlement areas, which are used as input for tsunami risk assessment. This paper presents the results of the development and application of classification techniques for settlement extraction using Landsat TM and TerraSAR-X imagery. Several methods, like region growing, Index based built up index (IBI) and speckle divergence methods, have been investigated to extract settlement areas in the districts of Cilacap and Padang. The decision tree and neighborhood algorithm has also been used for performing the classification steps. The results of this research are promising, especially the SAR techniques based on TerraSAR-X gave highly accurate results with more than 85% overall accuracy and low omission and commission errors. Keyword: Remote Sensing, Settlement Mapping, Region Growing, Index Based Built-up Index, SAR Speckle Divergence

  18. Polarimetric and three dimensional mapping of shallow subsurface structural elements in mafic pyroclastics using mid- and high-frequency Ground Penetrating Radar (GPR).

    NASA Astrophysics Data System (ADS)

    Heggy, E.; Clifford, S. M.; Hughes, S. S.

    2006-12-01

    Volcanic terrains are among the most prevalent on Mars, their structural and stratigraphical investigation by GPR providing a powerful tool for understanding the mechanisms and chronological sequence that resulted in their formation. For this reason, a broadband (0.5 1.5 GHz) GPR was selected as one of the primary instruments for the European Space Agency's ExoMars rover that will be sent to Mars in 2011. As part of the effort to evaluate the potential of this technique, we carried out a parametric study of several features at Craters of the Moon (COM) National Monument in Idaho (USA). This area, which includes expansive lave fields and volcanic constructs, is a hyper-arid environment with an average annual precipitation of less than ~50 mm. It also displays considerable geochemical and geomorphological similarity to a variety of volcanic regions on Mars. Among the examples we investigated were a large cinder cone (Inferno Cone) and surrounding smooth- and rough-surfaced basaltic lava flows. We conducted multiple frequency 270-, 500- and 900-MHz GPR surveys, with both VV and HH polarizations, in both orthogonal and grid form in order to perform a three dimensional mapping of the consolidated core of the cinder cone beneath a thick layer (1-20 m) of tephra that accumulated as a result of different eruptive events. Analysis of the resulting data indicates maximum sounding depths of ~13 m deep at 270 MHz, 8 m at 500 MHz and 5 m at 900 MHz in the unconsolidated tephra. Our gridded profiles show that the tephra distribution over the consolidated core is asymmetric, the eastern side being covered by thicker deposits than elsewhere. Our preliminary results also suggest the potential presence of a small spatter cone beneath the eastern flank of the cone. A similar approach was used to investigate the Blue Dragon basaltic lava field located to the south of Inferno Cone. The observed penetration depths were an order of magnitude smaller due to the high density of the flow

  19. A radar image time series

    NASA Technical Reports Server (NTRS)

    Leberl, F.; Fuchs, H.; Ford, J. P.

    1981-01-01

    A set of ten side-looking radar images of a mining area in Arizona that were aquired over a period of 14 yr are studied to demonstrate the photogrammetric differential-rectification technique applied to radar images and to examine changes that occurred in the area over time. Five of the images are rectified by using ground control points and a digital height model taken from a map. Residual coordinate errors in ground control are reduced from several hundred meters in all cases to + or - 19 to 70 m. The contents of the radar images are compared with a Landsat image and with aerial photographs. Effects of radar system parameters on radar images are briefly reviewed.

  20. Spaceborne radar

    NASA Technical Reports Server (NTRS)

    Moore, R. K.; Eckerman, J.; Meneghini, R.; Atlas, D.; Boerner, W. M.; Cherry, S.; Clark, J. F.; Doviak, R. J.; Goldhirsh, J.; Lhermitte, R. M.

    1981-01-01

    The spaceborne radar panel considered how radar could be used to measure precipitation from satellites. The emphasis was on how radar could be used with radiometry (at microwave, visible (VIS), and infrared (IR) wavelengths) to reduce the uncertainties of measuring precipitation with radiometry alone. In addition, the fundamental electromagnetic interactions involved in the measurements were discussed to determine the key work areas for research and development to produce effective instruments. Various approaches to implementing radar systems on satellites were considered for both shared and dedicated instruments. Finally, a research and development strategy was proposed for establishing the parametric relations and retrieval algorithms required for extracting precipitation information from the radar and associated radiometric data.

  1. Radar Imaging of Mercury

    NASA Astrophysics Data System (ADS)

    Harmon, John K.

    2007-10-01

    Earth-based radar has been one of the few, and one of the most important, sources of new information about Mercury during the three decades since the Mariner 10 encounters. The emphasis during the past 15 years has been on full-disk, dual-polarization imaging of the planet, an effort that has been facilitated by the development of novel radar techniques and by improvements in radar systems. Probably the most important result of the imaging work has been the discovery and mapping of radar-bright features at the poles. The radar scattering properties of these features, and their confinement to permanently shaded crater floors, is consistent with volume backscatter from a low-loss volatile such as clean water ice. Questions remain, however, regarding the source and long-term stability of the putative ice, which underscores the need for independent confirmation by other observational methods. Radar images of the non-polar regions have also revealed a plethora of bright features, most of which are associated with fresh craters and their ejecta. Several very large impact features, with rays and other bright ejecta spreading over distances of 1,000 km or more, have been traced to source craters with diameters of 80-125 km. Among these large rayed features are some whose relative faintness suggests that they are being observed in an intermediate stage of degradation. Less extended ray/ejecta features have been found for some of the freshest medium-size craters such as Kuiper and Degas. Much more common are smaller (<40 km diameter) fresh craters showing bright rim-rings but little or no ray structure. These smaller radar-bright craters are particularly common over the H-7 quadrangle. Diffuse areas of enhanced depolarized brightness have been found in the smooth plains, including the circum-Caloris planitiae and Tolstoj Basin. This is an interesting finding, as it is the reverse of the albedo contrast seen between the radar-dark maria and the radar-bright cratered highlands

  2. Radar Imaging of Mercury

    NASA Astrophysics Data System (ADS)

    Harmon, John K.

    Earth-based radar has been one of the few, and one of the most important, sources of new information about Mercury during the three decades since the Mariner 10 encounters. The emphasis during the past 15 years has been on full-disk, dual-polarization imaging of the planet, an effort that has been facilitated by the development of novel radar techniques and by improvements in radar systems. Probably the most important result of the imaging work has been the discovery and mapping of radar-bright features at the poles. The radar scattering properties of these features, and their confinement to permanently shaded crater floors, is consistent with volume backscatter from a low-loss volatile such as clean water ice. Questions remain, however, regarding the source and long-term stability of the putative ice, which underscores the need for independent confirmation by other observational methods. Radar images of the non-polar regions have also revealed a plethora of bright features, most of which are associated with fresh craters and their ejecta. Several very large impact features, with rays and other bright ejecta spreading over distances of 1,000 km or more, have been traced to source craters with diameters of 80-125 km. Among these large rayed features are some whose relative faintness suggests that they are being observed in an intermediate stage of degradation. Less extended ray/ejecta features have been found for some of the freshest medium-size craters such as Kuiper and Degas. Much more common are smaller (<40 km diameter) fresh craters showing bright rim-rings but little or no ray structure. These smaller radar-bright craters are particularly common over the H-7 quadrangle. Diffuse areas of enhanced depolarized brightness have been found in the smooth plains, including the circum-Caloris planitiae and Tolstoj Basin. This is an interesting finding, as it is the reverse of the albedo contrast seen between the radar-dark maria and the radar-bright cratered highlands

  3. Simulation of a weather radar display for over-water airborne radar approaches

    NASA Technical Reports Server (NTRS)

    Clary, G. R.

    1983-01-01

    Airborne radar approach (ARA) concepts are being investigated as a part of NASA's Rotorcraft All-Weather Operations Research Program on advanced guidance and navigation methods. This research is being conducted using both piloted simulations and flight test evaluations. For the piloted simulations, a mathematical model of the airborne radar was developed for over-water ARAs to offshore platforms. This simulated flight scenario requires radar simulation of point targets, such as oil rigs and ships, distributed sea clutter, and transponder beacon replies. Radar theory, weather radar characteristics, and empirical data derived from in-flight radar photographs are combined to model a civil weather/mapping radar typical of those used in offshore rotorcraft operations. The resulting radar simulation is realistic and provides the needed simulation capability for ongoing ARA research.

  4. RADAR WARNING SYSTEM,

    DTIC Science & Technology

    RADAR TRACKING, *AIRCRAFT DEFENSE SYSTEMS, RADAR EQUIPMENT, AIR TO AIR, SEARCH RADAR, GUIDED MISSILES, HIGH SPEED BOMBING, EARLY WARNING SYSTEMS, FIRE CONTROL SYSTEM COMPONENTS, AIRCRAFT, TIME, CHINA.

  5. Intra-eruption Geologic Map from an X-band Radar Image During the May 18, 1980 Eruption of Mount St. Helens, Washington

    NASA Technical Reports Server (NTRS)

    Criswell, C. W.; Elston, W. B.

    1985-01-01

    The use of side-looking airborne radar images for geologic interpretations has increased with the Vesuvian exploration projects. Interpretation of images without ground truth relies on examples in terrestrial environments for which geologic data are available.

  6. Large phased-array radars

    SciTech Connect

    Brookner, D.E.

    1988-12-15

    Large phased-array radars can play a very important part in arms control. They can be used to determine the number of RVs being deployed, the type of targeting of the RVs (the same or different targets), the shape of the deployed objects, and possibly the weight and yields of the deployed RVs. They can provide this information at night as well as during the day and during rain and cloud covered conditions. The radar can be on the ground, on a ship, in an airplane, or space-borne. Airborne and space-borne radars can provide high resolution map images of the ground for reconnaissance, of anti-ballistic missile (ABM) ground radar installations, missile launch sites, and tactical targets such as trucks and tanks. The large ground based radars can have microwave carrier frequencies or be at HF (high frequency). For a ground-based HF radar the signal is reflected off the ionosphere so as to provide over-the-horizon (OTH) viewing of targets. OTH radars can potentially be used to monitor stealth targets and missile traffic.

  7. MER vistas: ground-truth for Earth-based radar

    NASA Technical Reports Server (NTRS)

    Haldemann, Albert F.; Larsen, Kristopher W.; Jurgens, Raymond F.; Golombek, Matthew P.; Slade, Martin A.

    2004-01-01

    Earth-based delay-Doppler radar observations of Mars with four receiving stations were carried out during the Mars oppositions of 2001 and 2003 in support of Mars Exploration Rover landing site selection. This interferometric planetary radar technique has demonstrated radar mapping of Mars with a 5 km spatial resolution.

  8. MIMO Radar: A Multi-Sensor Spatially Diverse Radar Architecture

    DTIC Science & Technology

    2008-08-28

    of the Cramer-Rao Lower bound (b)introduces the geometric dilution of precision ( GDOP ) metric and the contour mapping, providing an insight into the...of the Cramer-Rao Lower bound [1] (b)introduces the geometric dilution of precision ( GDOP ) metric and the contour 20090319186 i mapping [2], [3...radar systems by means of the Cramer-Rao Lower Bound and the geometric dilution of precision ( GDOP ) metric- area are presented in Section 3. The

  9. Simulation of imaging radar using graphics hardware acceleration

    NASA Astrophysics Data System (ADS)

    Peinecke, Niklas; Döhler, Hans-Ullrich; Korn, Bernd R.

    2008-04-01

    Extending previous works by Doehler and Bollmeyer we describe a new implementation of an imaging radar simulator. Our approach is based on using modern computer graphics hardware making heavy use of recent technologies like vertex and fragment shaders. Furthermore, to allow for a nearly realistic image we generate radar shadows implementing shadow map techniques in the programmable graphics hardware. The particular implementation is tailored to imitate millimeter wave (MMW) radar but could be extended for other types of radar systems easily.

  10. Planetary radar

    NASA Technical Reports Server (NTRS)

    Taylor, R. M.

    1980-01-01

    The radar astronomy activities supported by the Deep Space Network during June, July, and August 1980 are reported. The planetary bodies observed were Venus, Mercury, and the asteroid Toro. Data were obtained at both S and X band, and the observations were considered successful.

  11. Radars in space

    NASA Technical Reports Server (NTRS)

    Delnore, Victor E.

    1990-01-01

    The capabilities of active microwave devices operating from space (typically, radar, scatterometers, interferometers, and altimeters) are discussed. General radar parameters and basic radar principles are explained. Applications of these parameters and principles are also explained. Trends in space radar technology, and where space radars and active microwave sensors in orbit are going are discussed.

  12. TRMM radar

    NASA Technical Reports Server (NTRS)

    Okamoto, Kenichi

    1993-01-01

    The results of a conceptual design study and the performance of key components of the Bread Board Model (BBM) of the Tropical Rainfall Measuring Mission (TRMM) radar are presented. The radar, which operates at 13.8 GHz and is designed to meet TRMM mission objectives, has a minimum measurable rain rate of 0.5 mm/h with a range resolution of 250 m, a horizontal resolution of about 4 km, and a swath width of 220 km. A 128-element active phased array system is adopted to achieve contiguous scanning within the swath. The basic characteristics of BBM were confirmed by experiments. The development of EM started with the cooperation of NASDA and CRL.

  13. Radar Sounder

    DTIC Science & Technology

    1988-09-01

    over the shorter time period (resulting in a multilook SAR ) with the result that spatial resolution, the usual r~ason for using SAR techniques, degrades...Field - - - ALT 21. Sea Surface Topography - - - SAR , ALT 22. Ocean Waves (sea, swell, surf) V. Good Some V. Good SAR , ALT * with additional lower freq...OLS - Operational Line-scan System radiometer (4-6 GHz?) ALT - Altimeter •* good at low microwave SAR - Synthetic Aperture frequencies Radar + over

  14. COASP and CHASP Processors for Strip-map and Moving Target Adaptive Processing of EC CV-580 Synthetic Aperture Radar Data: Algorithms and Software Description

    DTIC Science & Technology

    2006-05-01

    synthetic aperture radar ( SAR ) since the late 1990’s in support of target detection and classification studies. Until recently, processing of data from...this SAR system has been carried out in-house using the Polarimetrc Generalized Airborne SAR Processor (PolGASP) that was developed at the Canada...COASP (Configurable Airborne SAR Processor) and CHASP (Chip Adaptive SAR Processor) processors have been developed to replace and augment PolGASP and

  15. Radar and optical mapping of surge persistence and marsh dieback along the New Jersey Mid-Atlantic coast after Hurricane Sandy

    USGS Publications Warehouse

    Rangoonwala, Amina; Enwright, Nicholas M.; Ramsey III, Elijah W.; Spruce, Joseph P.

    2016-01-01

    This study combined a radar-based time series of Hurricane Sandy surge and estimated persistence with optical sensor-based marsh condition change to assess potential causal linkages of surge persistence and marsh condition change along the New Jersey Atlantic Ocean coast. Results based on processed TerraSAR-X and COSMO-SkyMed synthetic aperture radar (SAR) images indicated that surge flooding persisted for 12 h past landfall in marshes from Great Bay to Great Egg Harbor Bay and up to 59 h after landfall in many back-barrier lagoon marshes. Marsh condition change (i.e. loss of green marsh vegetation) was assessed from optical satellite images (Satellite Pour l’Observation de la Terre and Moderate Resolution Imaging Spectroradiometer) collected before and after Hurricane Sandy. High change in condition often showed spatial correspondence, with high surge persistence in marsh surrounding the lagoon portion of Great Bay, while in contrast, low change and high persistence spatial correspondence dominated the interior marshes of the Great Bay and Great Egg Harbor Bay estuaries. Salinity measurements suggest that these areas were influenced by freshwater discharges after landfall possibly mitigating damage. Back-barrier marshes outside these regions exhibited mixed correspondences. In some cases, topographic features supporting longer surge persistence suggested that non-correspondence between radar and optical data-based results may be due to differential resilience; however, in many cases, reference information was lacking to determine a reason for non-correspondence.

  16. Radar image of Rio Sao Francisco, Brazil

    NASA Technical Reports Server (NTRS)

    2000-01-01

    This radar image acquired by SRTM shows an area south of the Sao Francisco River in Brazil. The area is predominantly scrub forest. Areas such as these are difficult to map by traditional methods because of frequent cloud cover and local inaccessibility. Image brightness differences in this image are caused by differences in vegetation type and density. Tributaries of the Sao Francisco are visible in the upper right. The Sao Francisco River is a major source of water for irrigation and hydroelectric power. Mapping such regions will allow scientists to better understand the relationships between flooding cycles, forestation and human influences on ecosystems.

    This radar image was obtained by the Shuttle Radar Topography Mission as part of its mission to map the Earth's topography. The image was acquired by just one of SRTM's two antennas, and consequently does not show topographic data but only the strength of the radar signal reflected from the ground. This signal, known as radar backscatter, provides insight into the nature of the surface, including its roughness, vegetation cover, and urbanization.

    The Shuttle Radar Topography Mission (SRTM), launched on February 11, 2000, uses the same radar instrument that comprised the Spaceborne Imaging Radar-C/X-Band Synthetic Aperture Radar (SIR-C/X-SAR) that flew twice on the Space Shuttle Endeavour in 1994. The mission is designed to collect three-dimensional measurements of the Earth's surface. To collect the 3-D data, engineers added a 60-meter-long (200-foot) mast, an additional C-band imaging antenna and improved tracking and navigation devices. The mission is a cooperative project between the National Aeronautics and Space Administration (NASA), the National Imagery and Mapping Agency (NIMA) and the German and Italian space agencies. It is managed by NASA's Jet Propulsion Laboratory, Pasadena, CA, for NASA's Earth Science Enterprise, Washington, DC.

  17. Venus - Detailed mapping of Maxwell Montes region

    NASA Astrophysics Data System (ADS)

    Alexandrov, Yu. N.; Crymov, A. A.; Kotelnikov, V. A.; Petrov, G. M.; Rzhiga, O. N.; Sidorenko, A. I.; Sinilo, V. P.; Zakharov, A. I.; Akim, E. L.; Basilevski, A. T.; Kadnichanski, S. A.; Tjuflin, Yu. S.

    1986-03-01

    From October 1983 to July 1984, the north hemisphere of Venus, from latitude 30° to latitude 90°, was mapped by means of the radar imagers and altimeters of the spacecraft Venera 15 and Venera 16. This report presents the results of the radar mapping of the Maxwell Montes region, one of the most interesting features of Venus' surface. A radar mosaic map and contour map have been compiled.

  18. Terrestrial Radar Observations of Gusev Crater, Mars

    NASA Astrophysics Data System (ADS)

    Larsen, K. W.; Haldemann, A. F.; Jurgens, R. F.; Slade, M. A.

    2003-12-01

    The Mars Exploration Rover, Spirit, was launched on June 10, 2003, and is scheduled to land on the floor of Gusev Crater in January 2004. The close opposition of Mars in the summer of 2003 provided a final opportunity to observe the Gusev Crater landing site using Earth-based radar telescopes prior to the Rover's arrival. Similar observations of the Terra Meridiani site in 2001 demonstrated the capabilities of delay-Doppler radar interferometry in mapping the radar properties of planetary surfaces. The 2003 observation suite includes data from four nights in which the observation's sub-radar track was within five degrees of latitude of the planned landing site. High resolution, approximately five kilometers per pixel, radar imaging of the landing site indicates a site that will be of low risk to the rover and provides testable predictions of the local surface roughness that the rover will encounter.

  19. space Radar Image of Long Valley, California

    NASA Technical Reports Server (NTRS)

    1994-01-01

    An area near Long Valley, California, was mapped by the Spaceborne Imaging Radar-C and X-band Synthetic Aperture Radar aboard the space shuttle Endeavor on April 13, 1994, during the first flight of the radar instrument, and on October 4, 1994, during the second flight of the radar instrument. The orbital configurations of the two data sets were ideal for interferometric combination -- that is overlaying the data from one image onto a second image of the same area to create an elevation map and obtain estimates of topography. Once the topography is known, any radar-induced distortions can be removed and the radar data can be geometrically projected directly onto a standard map grid for use in a geographical information system. The 50 kilometer by 50 kilometer (31 miles by 31 miles) map shown here is entirely derived from SIR-C L-band radar (horizontally transmitted and received) results. The color shown in this image is produced from the interferometrically determined elevations, while the brightness is determined by the radar backscatter. The map is in Universal Transverse Mercator (UTM) coordinates. Elevation contour lines are shown every 50 meters (164 feet). Crowley Lake is the dark feature near the south edge of the map. The Adobe Valley in the north and the Long Valley in the south are separated by the Glass Mountain Ridge, which runs through the center of the image. The height accuracy of the interferometrically derived digital elevation model is estimated to be 20 meters (66 feet) in this image. Spaceborne Imaging Radar-C and X-band Synthetic Aperture Radar (SIR-C/X-SAR) is part of NASA's Mission to Planet Earth. The radars illuminate Earth with microwaves, allowing detailed observations at any time, regardless of weather or sunlight conditions. SIR-C/X-SAR uses three microwave wavelengths: L-band (24 cm), C-band (6 cm) and X-band (3 cm). The multi-frequency data will be used by the international scientific community to better understand the global

  20. Radar Image, Hokkaido, Japan

    NASA Technical Reports Server (NTRS)

    2000-01-01

    The southeast part of the island of Hokkaido, Japan, is an area dominated by volcanoes and volcanic caldera. The active Usu Volcano is at the lower right edge of the circular Lake Toya-Ko and near the center of the image. The prominent cone above and to the left of the lake is Yotei Volcano with its summit crater. The city of Sapporo lies at the base of the mountains at the top of the image and the town of Yoichi -- the hometown of SRTM astronaut Mamoru Mohri -- is at the upper left edge. The bay of Uchiura-Wan takes up the lower center of the image. In this image, color represents elevation, from blue at the lowest elevations to white at the highest. The radar image has been overlaid to provide more details of the terrain. Due to a processing problem, an island in the center of this crater lake is missing and will be properly placed when further SRTM swaths are processed. The horizontal banding in this image is a processing artifact that will be removed when the navigation information collected by SRTM is fully calibrated. This image was acquired by the Shuttle Radar Topography Mission (SRTM) aboard the Space Shuttle Endeavour, launched on February 11, 2000. SRTM used the same radar instrument that comprised the Spaceborne Imaging Radar-C/X-Band Synthetic Aperture Radar (SIR-C/X-SAR) that flew twice on the Space Shuttle Endeavour in 1994. SRTM was designed to collect three-dimensional measurements of the Earth's surface. To collect the 3-D data, engineers added a 60-meter-long (200-foot) mast, installed additional C-band and X-band antennas, and improved tracking and navigation devices. The mission is a cooperative project between the National Aeronautics and Space Administration (NASA), the National Imagery and Mapping Agency (NIMA) of the U.S. Department of Defense (DoD), and the German and Italian space agencies. It is managed by NASA's Jet Propulsion Laboratory, Pasadena, CA, for NASA's Earth Science Enterprise, Washington, DC. Size: 100 by 150 kilometers

  1. Lunar topography - Global determination by radar.

    NASA Technical Reports Server (NTRS)

    Shapiro, I. I.; Zisk, S. H.; Rogers, A. E. E.; Slade, M. A.; Thompson, T. W.

    1972-01-01

    Previous methods used for two-dimensional radar mapping of the moon are contrasted with new techniques that add altitude information to the radar map. Delay-Doppler stereoscopy and delay-Doppler interferometry are shown to provide surface-height variations with higher accuracy and better global fidelity than has been possible previously. Sample results are presented for altitude contours on the moon as obtained with the Haystack and Westford radar systems of the Massachusetts Institute of Technology. An appendix describes the mathematical principles of delay-Doppler interferometry in determining the position of an arbitrary reflecting region of the lunar surface from measurements of the time delay, Doppler shift, and fringe phase of radar echoes from that region.

  2. Venus mapping

    NASA Technical Reports Server (NTRS)

    Batson, R. M.; Morgan, H. F.; Sucharski, Robert

    1991-01-01

    Semicontrolled image mosaics of Venus, based on Magellan data, are being compiled at 1:50,000,000, 1:10,000,000, 1:5,000,000, and 1:1,000,000 scales to support the Magellan Radar Investigator (RADIG) team. The mosaics are semicontrolled in the sense that data gaps were not filled and significant cosmetic inconsistencies exist. Contours are based on preliminary radar altimetry data that is subjected to revision and improvement. Final maps to support geologic mapping and other scientific investigations, to be compiled as the dataset becomes complete, will be sponsored by the Planetary Geology and Geophysics Program and/or the Venus Data Analysis Program. All maps, both semicontrolled and final, will be published as I-maps by the United States Geological Survey. All of the mapping is based on existing knowledge of the spacecraft orbit; photogrammetric triangulation, a traditional basis for geodetic control on planets where framing cameras were used, is not feasible with the radar images of Venus, although an eventual shift of coordinate system to a revised spin-axis location is anticipated. This is expected to be small enough that it will affect only large-scale maps.

  3. Shuttle Radar Topography Mission (SRTM)

    USGS Publications Warehouse

    ,

    2003-01-01

    Under an agreement with the National Aeronautics and Space Administration (NASA) and the Department of Defense's National Imagery and Mapping Agency (NIMA), the U.S. Geological Survey (USGS) is now distributing elevation data from the Shuttle Radar Topography Mission (SRTM). The SRTM is a joint project between NASA and NIMA to map the Earth's land surface in three dimensions at a level of detail unprecedented for such a large area. Flown aboard the NASA Space Shuttle Endeavour February 11-22, 2000, the SRTM successfully collected data over 80 percent of the Earth's land surface, for most of the area between 60? N. and 56? S. latitude. The SRTM hardware included the Spaceborne Imaging Radar-C (SIR-C) and X-band Synthetic Aperture Radar (X-SAR) systems that had flown twice previously on other space shuttle missions. The SRTM data were collected specifically with a technique known as interferometry that allows image data from dual radar antennas to be processed for the extraction of ground heights.

  4. Developing an Efficient and Cost Effective Ground-Penetrating Radar Field Methodology for Subsurface Exploration and Mapping of Cultural Resources on Public Lands

    DTIC Science & Technology

    2006-07-28

    3. Technical Approach 6 3.1 Procedures for Data Collection 6 3.2 Analysis of the GPR Data 7 4. Results and Discussion 14 4.1 CATS Site...Figure 20: Construction of the Hammer test bed 27 Figure 21: Hammer GPR amplitude maps using the 400 MHz antenna in dry conditions. 28 Figure 22...Hammer GPR amplitude maps using the 400 MHz antenna in wet conditions. 29 Figure 23: Hammer GPR amplitude maps using the 900 MHz antenna in wet

  5. Comet radar explorer

    NASA Astrophysics Data System (ADS)

    Farnham, Tony; Asphaug, Erik; Barucci, Antonella; Belton, Mike; Bockelee-Morvan, Dominique; Brownlee, Donald; Capria, Maria Teresa; Carter, Lynn; Chesley, Steve; Farnham, Tony; Gaskell, Robert; Gim, Young; Heggy, Essam; Herique, Alain; Klaasen, Ken; Kofman, Wlodek; Kreslavsky, Misha; Lisse, Casey; Orosei, Roberto; Plaut, Jeff; Scheeres, Dan

    The Comet Radar Explorer (CORE) is designed to perform a comprehensive and detailed exploration of the interior, surface, and inner coma structures of a scientifically impor-tant Jupiter family comet. These structures will be used to investigate the origins of cometary nuclei, their physical and geological evolution, and the mechanisms driving their spectacular activity. CORE is a high heritage spacecraft, injected by solar electric propulsion into orbit around a comet. It is capable of coherent deep radar imaging at decameter wavelengths, high resolution stereo color imaging, and near-IR imaging spectroscopy. Its primary objective is to obtain a high-resolution map of the interior structure of a comet nucleus at a resolution of ¿100 elements across the diameter. This structure shall be related to the surface geology and morphology, and to the structural details of the coma proximal to the nucleus. This is an ideal complement to the science from recent comet missions, providing insight into how comets work. Knowing the structure of the interior of a comet-what's inside-and how cometary activity works, is required before we can understand the requirements for a cryogenic sample return mission. But more than that, CORE is fundamental to understanding the origin of comets and their evolution in time. The mission is made feasible at low cost by the use of now-standard MARSIS-SHARAD reflec-tion radar imaging hardware and data processing, together with proven flight heritage of solar electric propulsion. Radar flight heritage has been demonstrated by the MARSIS radar on Mars Express (Picardi et al., Science 2005; Plaut et al., Science 2007), the SHARAD radar onboard the Mars Reconnaissance Orbiter (Seu et al., JGR 2007), and the LRS radar onboard Kaguya (Ono et al, EPS 2007). These instruments have discovered detailed subsurface structure to depths of several kilometers in a variety of terrains on Mars and the Moon. A reflection radar deployed in orbit about a comet

  6. Venus - First Radar Test

    NASA Technical Reports Server (NTRS)

    1990-01-01

    After traveling more than 1.5 billion kilometers (948 million miles), the Magellan spacecraft was inserted into orbit around Venus on Aug. 10, 1990. This mosaic consists of adjacent pieces of two Magellan image strips obtained on Aug. 16 in the first radar test. The radar test was part of a planned In Orbit Checkout sequence designed to prepare the Magellan spacecraft and radar to begin mapping after Aug. 31. The strip on the left was returned to the Goldstone Deep Space Network station in California; the strip to the right was received at the DSN in Canberra, Australia. A third station that will be receiving Magellan data is located near Madrid, Spain. Each image strip is 20 km (12 miles) wide and 16,000 km (10,000 miles) long. This mosaic is a small portion 80 km (50 miles) long. This image is centered at 21 degrees north latitude and 286.8 degrees east longitude, southeast of a volcanic highland region called Beta Regio. The resolution of the image is about 120 meters (400 feet), 10 times better than previous images of the same area of Venus, revealing many new geologic features. The bright line trending northwest southeast across the center of the image is a fracture or fault zone cutting the volcanic plains. In the upper left corner of the image, a multiple ring circular feature of probable volcanic origin can be seen, approximately 4.27 km (2.65 miles) across. The bright and dark variations seen in the plains surrounding these features correspond to volcanic lava flows of varying ages. The volcanic lava flows in the southern half of the image have been cut by north south trending faults. This area is similar geologically to volcanic deposits seen on Earth at Hawaii and the Snake River Plains in Idaho.

  7. Tests of ground-penetrating radar and induced polarization for mapping fluvial mine tailings on the floor of the Couer d'Alene River, Idaho

    USGS Publications Warehouse

    Campbell, David L.; Wynn, Jefferey C.; Box, Stephen E.; Bookstrom, Arthur A.; Horton, Robert J.

    1997-01-01

    In order to investigate sequences of toxic mine tailings that have settled in the bed of the Coeur d'Alene River, Idaho, (see figure 1) we improvised ways to make geophysical measurements on the river floor. To make ground penetrating radar (GPR) profiles, we mounted borehole antennas on a skid that was towed along the river bottom. To make induced polarization (IP) profiles, we devised a bottom streamer from a garden hose, lead strips, PVC standoffs, and insulated wire. Each approach worked and provided uniquely different information about the buried toxic sediments. GPR showed shallow stratigraphy, but did not directly detect the presence of contaminating metals. IP showed a zone of high chargeability that is probably due to pockets of relatively higher metal content. Neither method was able to define the base of the fluvial tailings section, at least in part because the IP streamer was deliberately designed to sample only the top three meters of sediments to maximize horizontal resolution.

  8. Radar systems for the water resources mission, volume 2

    NASA Technical Reports Server (NTRS)

    Moore, R. K.; Claassen, J. P.; Erickson, R. L.; Fong, R. K. T.; Hanson, B. C.; Komen, M. J.; Mcmillan, S. B.; Parashar, S. K.

    1976-01-01

    The application of synthetic aperture radar (SAR) in monitoring and managing earth resources was examined. The function of spaceborne radar is to provide maps and map imagery to be used for earth resource and oceanographic applications. Spaceborne radar has the capability of mapping the entire United States regardless of inclement weather; however, the imagery must have a high degree of resolution to be meaningful. Attaining this resolution is possible with the SAR system. Imagery of the required quality must first meet mission parameters in the following areas: antenna patterns, azimuth and range ambiguities, coverage, and angle of incidence.

  9. Synthetic aperture radar in geosynchronous orbit

    NASA Technical Reports Server (NTRS)

    Tomiyasu, K.

    1978-01-01

    Radar images of the earth were taken with a synthetic aperture radar (SAR) from geosynchronous orbital ranges by utilizing satellite motion relative to a geostationary position. A suitable satellite motion was obtained by having an orbit plane inclined relative to the equatorial plane and by having an eccentric orbit. Potential applications of these SAR images are topography, water resource management and soil moisture determination. Preliminary calculations show that the United States can be mapped with 100 m resolution cells in about 4 hours. With the use of microwave signals the mapping can be performed day or night, through clouds and during adverse weather.

  10. Spaceborne imaging radar - Geologic and oceanographic applications

    NASA Technical Reports Server (NTRS)

    Elachi, C.

    1980-01-01

    Synoptic, large-area radar images of the earth's land and ocean surface, obtained from the Seasat orbiting spacecraft, show the potential for geologic mapping and for monitoring of ocean surface patterns. Structural and topographic features such as lineaments, anticlines, folds and domes, drainage patterns, stratification, and roughness units can be mapped. Ocean surface waves, internal waves, current boundaries, and large-scale eddies have been observed in numerous images taken by the Seasat imaging radar. This article gives an illustrated overview of these applications.

  11. Shuttle Radar Topography Mission (SRTM)

    USGS Publications Warehouse

    ,

    2009-01-01

    Under an agreement with the National Aeronautics and Space Administration (NASA) and the Department of Defense's National Geospatial-Intelligence Agency (NGA), the U.S. Geological Survey (USGS) is distributing elevation data from the Shuttle Radar Topography Mission (SRTM). The SRTM is a joint project of NASA and NGA to map the Earth's land surface in three dimensions at an unprecedented level of detail. As part of space shuttle Endeavour's flight during February 11-22, 2000, the SRTM successfully collected data over 80 percent of the Earth's land surface for most of the area between latitudes 60 degrees north and 56 degrees south. The SRTM hardware included the Spaceborne Imaging Radar-C (SIR-C) and X-band Synthetic Aperture Radar (X-SAR) systems that had flown twice previously on other space shuttle missions. The SRTM data were collected with a technique known as interferometry that allows image data from dual radar antennas to be processed for the extraction of ground heights.

  12. The proposed flatland radar

    NASA Technical Reports Server (NTRS)

    Green, J. L.; Gage, K. S.; Vanzandt, T. E.; Nastrom, G. D.

    1986-01-01

    A flexible very high frequency (VHF) stratosphere-troposphere (ST) radar configured for meteorological research is to be constructed near Urbana, Illinois. Measurement of small vertical velocities associated with synoptic-scale meteorology can be performed. A large Doppler microwave radar (CHILL) is located a few km from the site of the proposed ST radar. Since the microwave radar can measure the location and velocity of hydrometeors and the VHF ST radar can measure clear (or cloudy) air velocities, simultaneous observations by these two radars of stratiform or convective weather systems would provide valuable meteorological information.

  13. A Perspective of Synthetic Aperture Radar for Remote Sensing.

    DTIC Science & Technology

    1978-05-01

    capability was first demonstrated by the Soviets using conventional imaging radar from a i r c ra f t . b) Geological and mineral exploration This is the prime...tool for petroleum exploration. Imaging radar has also been used for mapping and mineral exploration of inaccessible areas by several South American

  14. Space Radar Image of Munich, Germany

    NASA Technical Reports Server (NTRS)

    1994-01-01

    This spaceborne radar image of Munich, Germany illustrates the capability of a multi-frequency radar system to highlight different land use patterns in the area surrounding Bavaria's largest city. Central Munich is the white area at the middle of the image, on the banks of the Isar River. Pink areas are forested, while green areas indicate clear-cut and agricultural terrain. The Munich region served as a primary 'supersite' for studies in ecology, hydrology and radar calibration during the Spaceborne Imaging Radar-C/X-Band Synthetic Aperture Radar (SIR-C/X-SAR) missions. Scientists were able to use these data to map patterns of forest damage from storms and areas affected by bark beetle infestation. The image was acquired by SIR-C/X-SAR onboard the space shuttle Endeavour on April 18, 1994. The image is 37 kilometers by 32 kilometers (23 miles by 20 miles) and is centered at 48.2 degrees North latitude, 11.5 degrees East longitude. North is toward the upper right. The colors are assigned to different radar frequencies and polarizations of the radar as follows: red is L-band, vertically transmitted and horizontally received; green is C-band, vertically transmitted and horizontally received; and blue is C-band vertically transmitted and received. SIR-C/X-SAR, a joint mission of the German, Italian, and United States space agencies, is part of NASA's Mission to Planet Earth.

  15. Survey of Ultra-wideband Radar

    NASA Astrophysics Data System (ADS)

    Mokole, Eric L.; Hansen, Pete

    The development of UWB radar over the last four decades is very briefly summarized. A discussion of the meaning of UWB is followed by a short history of UWB radar developments and discussions of key supporting technologies and current UWB radars. Selected UWB radars and the associated applications are highlighted. Applications include detecting and imaging buried mines, detecting and mapping underground utilities, detecting and imaging objects obscured by foliage, through-wall detection in urban areas, short-range detection of suicide bombs, and the characterization of the impulse responses of various artificial and naturally occurring scattering objects. In particular, the Naval Research Laboratory's experimental, low-power, dual-polarized, short-pulse, ultra-high resolution radar is used to discuss applications and issues of UWB radar. Some crucial issues that are problematic to UWB radar are spectral availability, electromagnetic interference and compatibility, difficulties with waveform control/shaping, hardware limitations in the transmission chain, and the unreliability of high-power sources for sustained use above 2 GHz.

  16. Investigating nearby exoplanets via interstellar radar

    NASA Astrophysics Data System (ADS)

    Scheffer, Louis K.

    2014-01-01

    Interstellar radar is a potential intermediate step between passive observation of exoplanets and interstellar exploratory missions. Compared with passive observation, it has the traditional advantages of radar astronomy. It can measure surface characteristics, determine spin rates and axes, provide extremely accurate ranges, construct maps of planets, distinguish liquid from solid surfaces, find rings and moons, and penetrate clouds. It can do this even for planets close to the parent star. Compared with interstellar travel or probes, it also offers significant advantages. The technology required to build such a radar already exists, radar can return results within a human lifetime, and a single facility can investigate thousands of planetary systems. The cost, although too high for current implementation, is within the reach of Earth's economy.

  17. A radar-echo model for Mars

    NASA Technical Reports Server (NTRS)

    Thompson, T. W.; Moore, H. J.

    1990-01-01

    Researchers developed a radar-echo model for Mars based on 12.6 cm continuous wave radio transmissions backscattered from the planet. The model broadly matches the variations in depolarized and polarized total radar cross sections with longitude observed by Goldstone in 1986 along 7 degrees S. and yields echo spectra that are generally similiar to the observed spectra. Radar map units in the model include an extensive cratered uplands unit with weak depolarized echo cross sections, average thermal inertias, moderate normal refelectivities, and moderate rms slopes; the volcanic units of Tharsis, Elysium, and Amazonis regions with strong depolarized echo cross sections, low thermal inertia, low normal reflectivities, and large rms slopes; and the northern planes units with moderate to strong depolarized echo cross sections, moderate to very high thermal inertias, moderate to large normal reflectivities, and moderate rms slopes. The relevance of the model to the interpretation of radar echoes from Mars is discussed.

  18. A radar image of Venus.

    NASA Technical Reports Server (NTRS)

    Goldstein, R. M.; Rumsey, H. C.

    1972-01-01

    Radar scans of Venus have yielded a brightness map of a large portion of the surface. The bright area in the south (alpha) and the twin such areas in the north (beta and delta) were first discovered by spectral analysis of radar echos. When range-gating is also applied, their shapes are revealed, and they are seen to be roundish and about 1000 km across. Although radar brightness can be the result of either intrinsic reflectivity or surface roughness, polarization studies show these features to be rough (to the scale of the wavelength, 12.5 cm). Dark, circular areas can also be seen, many with bright central spots. The dark areas are probably smooth. The blurring of the equatorial strip is an artifact of the range-Doppler geometry; all resolution disappears at the equator. Another artifact of the method is the 'ghost', in the south, of the images of beta and delta. Such ghosts appear only at the eastern and western extremes of the map.

  19. Urban Flood Warning Systems using Radar Technologies

    NASA Astrophysics Data System (ADS)

    Fang, N.; Bedient, P. B.

    2013-12-01

    There have been an increasing number of urban areas that rely on weather radars to provide accurate precipitation information for flood warning purposes. As non-structural tools, radar-based flood warning systems can provide accurate and timely warnings to the public and private entities in urban areas that are prone to flash floods. The wider spatial and temporal coverage from radar increases flood warning lead-time when compared to rain and stream gages alone. The Third Generation Rice and Texas Medical Center (TMC) Flood Alert System (FAS3) has been delivering warning information with 2 to 3 hours of lead time and a R2 value of 93% to facility personnel in a readily understood format for more than 50 events in the past 15 years. The current FAS utilizes NEXRAD Level II radar rainfall data coupled with a real-time hydrologic model (RTHEC-1) to deliver warning information. The system has a user-friendly dashboard to provide rainfall maps, Google Maps based inundation maps, hydrologic predictions, and real-time monitoring at the bayou. This paper will evaluate its reliable performance during the recent events occurring in 2012 and 2013 and the development of a similar radar-based flood warning system for the City of Sugar Land, Texas. Having a significant role in the communication of flood information, FAS marks an important step towards the establishment of an operational and reliable flood warning system for flood-prone urban areas.

  20. Weather Radar Technology Development

    DTIC Science & Technology

    1990-08-15

    uelocitV WMs ) data processing systems such as NEXRAD to have a reliable technique for removing ambiguities due to velocity aliasing. Performance of many...intended for automated implementation on radar systems such as the NEXt generation weather RADar ( NEXRAD ) system. Several research areas were addressed...with Doppler radar will soon be realized with the deployment of the NEXRAD radar systems. Some of these large scale storms can have devastating wind

  1. Space radar image of Ubar optical/radar

    NASA Technical Reports Server (NTRS)

    1995-01-01

    This pair of images from space shows a portion of the southern Empty Quarter of the Arabian Peninsula in the country of Oman. On the left is a radar image of the region around the site of the fabled Lost City of Ubar, discovered in 1992 with the aid of remote sensing data. On the right is an enhanced optical image taken by the shuttle astronauts. Ubar existed from about 2800 BC to about 300 AD. and was a remote desert outpost where caravans were assembled for the transport of frankincense across the desert. The actual site of the fortress of the Lost City of Ubar, currently under excavation, is too small to show in either image. However, tracks leading to the site, and surrounding tracks, show as prominent, but diffuse, reddish streaks in the radar image. Although used in modern times, field investigations show many of these tracks were in use in ancient times as well. Mapping of these tracks on regional remote sensing images provided by the Landsat satellite was a key to recognizing the site as Ubar. The prominent magenta colored area is a region of large sand dunes. The green areas are limestone rocks, which form a rocky desert floor. A major wadi, or dry stream bed, runs across the scene and appears as a white line. The radar images, and ongoing field investigations, will help shed light on an early civilization about which little in known. The radar image was taken by the Spaceborne Imaging Radar C/X-Band Synthetic Aperture Radar (SIR-C/X-SAR) and is centered at 18 degrees North latitude and 53 degrees East longitude. The image covers an area about 50 kilometers by 100 kilometers (31 miles by 62 miles). The colors in the image are assigned to different frequencies and polarizations of the radar as follows: red is L-band, horizontally transmitted, horizontally received; blue is C-band horizontally transmitted, horizontally received; green is L-band horizontally transmitted, vertically received. SIR-C/X-SAR, a joint mission of the German, Italian and the United

  2. Radar: Human Safety Net

    ERIC Educational Resources Information Center

    Ritz, John M.

    2016-01-01

    Radar is a technology that can be used to detect distant objects not visible to the human eye. A predecessor of radar, called the telemobiloscope, was first used to detect ships in the fog in 1904 off the German coast. Many scientists have worked on the development and refinement of radar (Hertz with electromagnetic waves; Popov with determining…

  3. The Shuttle Radar Topography Mission

    NASA Astrophysics Data System (ADS)

    Farr, T. G.; Kobrick, M.

    2001-12-01

    The Shuttle Radar Topography Mission (SRTM), which flew successfully aboard Endeavour in February 2000, is a cooperative project between NASA, the National Imagery and Mapping Agency, and the German and Italian Space Agencies. The mission was designed to use a single-pass radar interferometer to produce a digital elevation model of the Earth's land surface between about 60 degrees north and 56 degrees south latitude. The DEM will have 30 m horizontal resolution and better than 15 m vertical errors. Two ortho-rectified C-band image mosaics are also planned. Data processing will be completed by the end of 2002. SRTM used a modification of the radar instrument that comprised the Spaceborne Radar Laboratory that flew twice on the Shuttle Endeavour in 1994. To collect the interferometric data, a 60 m mast, additional C-band antenna, and improved tracking and navigation devices were added. A second X-band antenna was also added by the German Space Agency, and produced higher resolution topographic measurements in strips nested within the full, C-band coverage. First results indicate that the radars and ancillary instruments worked very well. Data played back to the ground during the flight were processed to DEMs and products released hours after acquisition. An extensive program for calibration and verification of the SRTM data is now underway. When complete later this year, systematic processing of the data will begin, with final products emerging a continent at a time. Products will be transferred to the US Geological Survey's EROS Data Center for civilian archive and distribution. NIMA will handle Department of Defense distribution. * Work performed under contract to NASA.

  4. The Shuttle Radar Topography Mission

    NASA Astrophysics Data System (ADS)

    Farr, T. G.; Kobrick, M.

    2001-05-01

    The Shuttle Radar Topography Mission (SRTM), which flew successfully aboard Endeavour in February 2000, is a cooperative project between NASA and the National Imagery and Mapping Agency (NIMA). The mission was designed to use a single-pass radar interferometer to produce a digital elevation model of the Earth's land surface between about 60 degrees north and 56 degrees south latitude. The DEM will have 30 m horizontal resolution and about 15 m vertical errors. Two ortho-rectified C-band image mosaics are also planned. SRTM used a modification of the radar instrument that comprised the Spaceborne Radar Laboratory that flew twice on the Shuttle Endeavour in 1994. To collect the interferometric data, a 60 m mast, additional C-band antenna, and improved tracking and navigation devices were added. A second X-band antenna was also added by the German Space Agency, and produced higher resolution topographic measurements in strips nested within the full, C-band coverage. First results indicate that the radars and ancillary instruments worked very well. Data played back to the ground during the flight were processed to DEMs and products released hours after acquisition. An extensive program for calibration and verification of the SRTM data is now underway. When complete later this year, systematic processing of the data will begin, with final products emerging a continent at a time. Data processing will be completed by the end of 2002. Products will be transferred to the US Geological Survey's EROS Data Center for civilian archive and distribution. NIMA will handle Department of Defense distribution. * Work performed under contract to NASA.

  5. Shuttle Radar Topographic Mission (SRTM) Illustration

    NASA Technical Reports Server (NTRS)

    2000-01-01

    Launched February 11, 2000, the STS-99 Shuttle Radar Topographic Mission (SRTM) was the most ambitious Earth mapping mission to date. This illustration shows the Space Shuttle Endeavour orbiting some 145 miles (233 kilometers) above Earth. With C-band and X-band outboard anternae at work, one located in the Shuttle bay and the other located on the end of a 60-meter deployable mast, the SRTM radar was able to penetrate clouds as well as provide its own illumination, independent of daylight, obtaining 3-dimentional topographic images of the world's surface up to the Arctic and Antarctic Circles. The mission completed 222 hours of around the clock radar mapping, gathering enough information to fill more than 20,000 CDs.

  6. Characterization and high resolution mapping of soil hydrogeophysical properties from ground penetrating radar and electromagnetic induction data in a vineyard in southern France

    NASA Astrophysics Data System (ADS)

    Andre, F.; van Durmen, R.; Saussez, S.; van Leeuwen, C.; Moghadas, D.; Delvaux, B.; Vereecken, H.; Sebastien, L.

    2010-12-01

    Soil and climate are acknowledged to greatly affect vine growth and grape berry composition through their strong influence on vine water status. Over a limited area, climatic factors may be considered as rather homogeneous for a given vintage while soil characteristics may vary strongly over short distances. Therefore, detailed characterization of soil hydrogeophysical properties is of prime importance for the definition of optimal vineyard practices. In that respect, ground penetrating radar (GPR) and electromagnetic induction (EMI) are effective geophysical techniques for fast and non-invasive determination of shallow subsurface properties through the measurement of soil dielectric permittivity and electrical conductivity. Given contrasted sensitivities of GPR and EMI to soil electrical properties, combining measurements from both techniques allows to merge complementary information, thereby leading to more accurate quantitative characterisation of soil. Classical GPR and EMI data processing techniques for soil properties characterisation rely on strongly simplifying assumptions in the modelling of electromagnetic phenomena, leading to significant errors on the estimates and accounting for only a part of the data information content. We developed generalized multi-offset full-waveform approaches for modelling off-ground and on-ground GPR and EMI signals. GPR and EMI systems are modelled using sets of infinitesimal electric and magnetic dipoles, allowing us to properly describe the distribution of the scattered field when the subsurface is located in the near-field of the antenna. The antenna model is coupled with a three-dimensional Green’s function, corresponding to a specific solution of the Maxwell’s equations for wave propagation or diffusion in multilayered media. The approaches were applied in a vineyard in south of France (Saint-Emilion) over a 30-ha area characterized by strong spatial variations of soil types. Around 1 million GPR waveforms and 73

  7. VHF radar measurements over Andoya (Northern Norway)

    NASA Technical Reports Server (NTRS)

    Czechowsky, P.; Reid, I. M.; Ruester, R.; Schmidt, G.

    1989-01-01

    The Mobile SOUSY Radar was operated during the MAP/WINE, the MAC/SINE, and MAC/Epsilon campaigns at Andoya in Northern Norway. A comparison between summer and winter results is presented, in particular the generation and development of the scattering regions, the different power spectral densities and the aspect sensitivities which were derived from six different beam directions.

  8. The Comet Radar Explorer Mission

    NASA Astrophysics Data System (ADS)

    Asphaug, Erik; Belton, Mike; Bockelee-Morvan, Dominique; Chesley, Steve; Delbo, Marco; Farnham, Tony; Gim, Yonggyu; Grimm, Robert; Herique, Alain; Kofman, Wlodek; Oberst, Juergen; Orosei, Roberto; Piqueux, Sylvain; Plaut, Jeff; Robinson, Mark; Sava, Paul; Heggy, Essam; Kurth, William; Scheeres, Dan; Denevi, Brett; Turtle, Elizabeth; Weissman, Paul

    2014-11-01

    Missions to cometary nuclei have revealed major geological surprises: (1) Global scale layers - do these persist through to the interior? Are they a record of primary accretion? (2) Smooth regions - are they landslides originating on the surface? Are they cryovolcanic? (3) Pits - are they impact craters or sublimation pits, or rooted in the interior? Unambiguous answers to these and other questions can be obtained by high definition 3D radar reflection imaging (RRI) of internal structure. RRI can answer many of the great unknowns in planetary science: How do primitive bodies accrete? Are cometary nuclei mostly ice? What drives their spectacular activity and evolution? The Comet Radar Explorer (CORE) mission will image the detailed internal structure of the nucleus of 10P/Tempel 2. This ~16 x 8 x 7 km Jupiter Family Comet (JFC), or its parent body, originated in the outer planets region possibly millions of years before planet formation. CORE arrives post-perihelion and observes the comet’s waning activity from safe distance. Once the nucleus is largely dormant, the spacecraft enters a ~20-km dedicated Radar Mapping Orbit (RMO). The exacting design of the RRI experiment and the precise navigation of RMO will achieve a highly focused 3D radar reflection image of internal structure, to tens of meters resolution, and tomographic images of velocity and attenuation to hundreds of meters resolution, tied to the gravity model and shape. Visible imagers will produce maps of the surface morphology, albedo, color, texture, and photometric response, and images for navigation and shape determination. The cameras will also monitor the structure and dynamics of the coma, and its dusty jets, allowing their correlation in 3D with deep interior structures and surface features. Repeated global high-resolution thermal images will probe the near-surface layers heated by the Sun. Derived maps of thermal inertia will be correlated with the radar boundary response, and photometry and

  9. Radar stage uncertainty

    USGS Publications Warehouse

    Fulford, J.M.; Davies, W.J.

    2005-01-01

    The U.S. Geological Survey is investigating the performance of radars used for stage (or water-level) measurement. This paper presents a comparison of estimated uncertainties and data for radar water-level measurements with float, bubbler, and wire weight water-level measurements. The radar sensor was also temperature-tested in a laboratory. The uncertainty estimates indicate that radar measurements are more accurate than uncorrected pressure sensors at higher water stages, but are less accurate than pressure sensors at low stages. Field data at two sites indicate that radar sensors may have a small negative bias. Comparison of field radar measurements with wire weight measurements found that the radar tends to measure slightly lower values as stage increases. Copyright ASCE 2005.

  10. Radar studies of the planets. [radar measurements of lunar surface, Mars, Mercury, and Venus

    NASA Technical Reports Server (NTRS)

    Ingalls, R. P.; Pettengill, G. H.; Rogers, A. E. E.; Sebring, P. B. (Editor); Shapiro, I. I.

    1974-01-01

    The radar measurements phase of the lunar studies involving reflectivity and topographic mapping of the visible lunar surface was ended in December 1972, but studies of the data and production of maps have continued. This work was supported by Manned Spacecraft Center, Houston. Topographic mapping of the equatorial regions of Mars has been carried out during the period of each opposition since that of 1967. The method comprised extended precise traveling time measurements to a small area centered on the subradar point. As measurements continued, planetary motions caused this point to sweep out extensive areas in both latitude and longitude permitting the development of a fairly extensive topographical map in the equatorial region. Radar observations of Mercury and Venus have also been made over the past few years. Refinements of planetary motions, reflectivity maps and determinations of rotation rates have resulted.

  11. Airborne Radar Interferometric Repeat-Pass Processing

    NASA Technical Reports Server (NTRS)

    Hensley, Scott; Michel, Thierry R.; Jones, Cathleen E.; Muellerschoen, Ronald J.; Chapman, Bruce D.; Fore, Alexander; Simard, Marc; Zebker, Howard A.

    2011-01-01

    Earth science research often requires crustal deformation measurements at a variety of time scales, from seconds to decades. Although satellites have been used for repeat-track interferometric (RTI) synthetic-aperture-radar (SAR) mapping for close to 20 years, RTI is much more difficult to implement from an airborne platform owing to the irregular trajectory of the aircraft compared with microwave imaging radar wavelengths. Two basic requirements for robust airborne repeat-pass radar interferometry include the ability to fly the platform to a desired trajectory within a narrow tube and the ability to have the radar beam pointed in a desired direction to a fraction of a beam width. Uninhabited Aerial Vehicle Synthetic Aperture Radar (UAVSAR) is equipped with a precision auto pilot developed by NASA Dryden that allows the platform, a Gulfstream III, to nominally fly within a 5 m diameter tube and with an electronically scanned antenna to position the radar beam to a fraction of a beam width based on INU (inertial navigation unit) attitude angle measurements.

  12. Radar images analysis for scattering surfaces characterization

    NASA Astrophysics Data System (ADS)

    Piazza, Enrico

    1998-10-01

    According to the different problems and techniques related to the detection and recognition of airplanes and vehicles moving on the Airport surface, the present work mainly deals with the processing of images gathered by a high-resolution radar sensor. The radar images used to test the investigated algorithms are relative to sequence of images obtained in some field experiments carried out by the Electronic Engineering Department of the University of Florence. The radar is the Ka band radar operating in the'Leonardo da Vinci' Airport in Fiumicino (Rome). The images obtained from the radar scan converter are digitized and putted in x, y, (pixel) co- ordinates. For a correct matching of the images, these are corrected in true geometrical co-ordinates (meters) on the basis of fixed points on an airport map. Correlating the airplane 2-D multipoint template with actual radar images, the value of the signal in the points involved in the template can be extracted. Results for a lot of observation show a typical response for the main section of the fuselage and the wings. For the fuselage, the back-scattered echo is low at the prow, became larger near the center on the aircraft and than it decrease again toward the tail. For the wings the signal is growing with a pretty regular slope from the fuselage to the tips, where the signal is the strongest.

  13. 2. VIEW SOUTHWEST, prime search radar tower, height finder radar ...

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

    2. VIEW SOUTHWEST, prime search radar tower, height finder radar towards, height finder radar towers, and radar tower (unknown function) - Fort Custer Military Reservation, P-67 Radar Station, .25 mile north of Dickman Road, east of Clark Road, Battle Creek, Calhoun County, MI

  14. 78 FR 68861 - Certain Navigation Products, Including GPS Devices, Navigation and Display Systems, Radar Systems...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-11-15

    ..., Navigational Aids, Mapping Systems and Related Software; Institution of Investigation Pursuant to 19 U.S.C... and display systems, radar systems, navigational aids, mapping systems and related software by reason... products, including GPS devices, navigation and display systems, radar systems, navigational aids,...

  15. Radar tomography of bridge decks

    NASA Astrophysics Data System (ADS)

    Davidson, Nigel C.; Chase, Steven B.

    1998-03-01

    This paper presents the development of ground-penetrating radar bridge deck inspection systems sponsored by the Federal Highway Administration. Two radar systems have been designed and built by Lawrence Livermore National Laboratory. The HERMES bridge inspector (High-speed Electromagnetic Roadway Mapping and Evaluation System) is designed to survey the deck condition during normal traffic flow. Thus the need for traffic control during inspection is eliminated. This system employs a 64 channel antenna array covering 1.9 m in width with a sampling density of 3 cm. To investigate areas of a bridge deck that are of particular interest and require detailed inspection a slower, cart mounted radar has been produced. This system is named PERES (Precision Electromagnetic Roadway Evaluation System). The density of data coverage with PERES is 1 cm and an average or 100 samples is taken at each location to improve the signal to noise ratio. Images of the deck interior are reconstructed from the original data using synthetic aperture tomography. The target of these systems is the location of steel reinforcement, corrosion related delaminations, voids and disbonds. The final objective is for these, and other non-destructive technologies, to provide information on the condition of the nation's bridges so that funds will be spent on the structures in most need of repair.

  16. Space Radar Image of Owens Valley, California

    NASA Technical Reports Server (NTRS)

    1999-01-01

    This is a three-dimensional perspective view of Owens Valley, near the town of Bishop, California that was created by combining two spaceborne radar images using a technique known as interferometry. Visualizations like this one are helpful to scientists because they clarify the relationships of the different types of surfaces detected by the radar and the shapes of the topographic features such as mountains and valleys. The view is looking southeast along the eastern edge of Owens Valley. The White Mountains are in the center of the image, and the Inyo Mountains loom in the background. The high peaks of the White Mountains rise more than 3,000 meters (10,000 feet) above the valley floor. The runways of the Bishop airport are visible at the right edge of the image. The meandering course of the Owens River and its tributaries appear light blue on the valley floor. Blue areas in the image are smooth, yellow areas are rock outcrops, and brown areas near the mountains are deposits of boulders, gravel and sand known as alluvial fans. The image was constructed by overlaying a color composite radar image on top of a digital elevation map. The radar data were taken by the Spaceborne Imaging Radar-C/X-band Synthetic Aperture Radar (SIR-C/X-SAR) on board the space shuttle Endeavour in October 1994. The digital elevation map was produced using radar interferometry, a process in which radar data are acquired on different passes of the space shuttle. The two data passes are compared to obtain elevation information. The elevation data were derived from a 1,500-km-long (930-mile) digital topographic map processed at JPL. Radar image data are draped over the topography to provide the color with the following assignments: red is L-band vertically transmitted, vertically received; green is C-band vertically transmitted, vertically received; and blue is the ratio of C-band vertically transmitted, vertically received to L-band vertically transmitted, vertically received. This image is

  17. Space Radar Image of Saline Valley, California

    NASA Technical Reports Server (NTRS)

    1999-01-01

    This is a three-dimensional perspective view of Saline Valley, about 30 km (19 miles) east of the town of Independence, California created by combining two spaceborne radar images using a technique known as interferometry. Visualizations like this one are helpful to scientists because they clarify the relationships of the different types of surfaces detected by the radar and the shapes of the topographic features such as mountains and valleys. The view is looking southwest across Saline Valley. The high peaks in the background are the Inyo Mountains, which rise more than 3,000 meters (10,000 feet) above the valley floor. The dark blue patch near the center of the image is an area of sand dunes. The brighter patches to the left of the dunes are the dry, salty lake beds of Saline Valley. The brown and orange areas are deposits of boulders, gravel and sand known as alluvial fans. The image was constructed by overlaying a color composite radar image on top of a digital elevation map. The radar image was taken by the Spaceborne Imaging Radar-C/X-bandSynthetic Aperture Radar (SIR-C/X-SAR) on board the space shuttleEndeavour in October 1994. The digital elevation map was producedusing radar interferometry, a process in which radar data are acquired on different passes of the space shuttle. The two data passes are compared to obtain elevation information. The elevation data were derived from a 1,500-km-long (930-mile) digital topographic map processed at JPL. Radar image data are draped over the topography to provide the color with the following assignments: red is L-band vertically transmitted, vertically received; green is C-band vertically transmitted, vetically received; and blue is the ratio of C-band vertically transmitted, vertically received to L-band vertically transmitted, vertically received. This image is centered near 36.8 degrees north latitude and 117.7 degrees west longitude. No vertical exaggeration factor has been applied to the data. SIR-C/X-SAR, a joint

  18. Evaluation of radar imagery for geological and cartographic applications

    USGS Publications Warehouse

    Moore, Gerald K.; Sheehan, Cynthia A.

    1981-01-01

    The House/Senate conference report on H.R. 4930 (96th Congress), the Department of the Interior and Related Agencies Appropriations bill, 1980, stated that the U.S. Geological Survey should "begin the use of side-looking airborne radar imagery for topographic and geological mapping, and geological resource surveys in promising areas, particularly Alaska." In response to this mandate, the Survey acquired radar data and began scientific studies to analyze and interpret these data. About 70 percent of the project funding was used to acquire radar imagery and to evaluate Alaskan applications. Results of these studies indicate that radar images have a unique incremental value for certain geologic and cartographic applications but that the images are best suited for use as supplemental information sources or as primary data sources in areas of persistent cloud cover.The value of radar data is greatest for geologic mapping and resource surveys, particularly for mineral and petroleum exploration, where the objective is to locate any single feature or group of features that may control the occurrences of these resources. Radar images are considered by oil and gas companies to be worth the cost of data acquisition within a limited area of active exploration.Radar images also have incremental value for geologic site studies and hazard mapping. The need in these cases is TO inventory all geologic hazards to human life, property, resources, and the environment. For other geologic applications, radar images have a relatively small incremental value over a combination of Landsat images and aerial photographs.The value of radar images for cartographic applications is minimal, except when they are used as a substitute for aerial photographs and topographic maps in persistently cloud-covered areas. If conventional data sources are not available, radar images provide useful information on terrain relief, landforms, drainage patterns, and land cover. Screen less lithography is a low

  19. 30. Perimeter acquisition radar building room #318, showing radar control. ...

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

    30. Perimeter acquisition radar building room #318, showing radar control. Console and line printers - Stanley R. Mickelsen Safeguard Complex, Perimeter Acquisition Radar Building, Limited Access Area, between Limited Access Patrol Road & Service Road A, Nekoma, Cavalier County, ND

  20. 3. VIEW NORTHWEST, height finder radar towers, and radar tower ...

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

    3. VIEW NORTHWEST, height finder radar towers, and radar tower (unknown function) - Fort Custer Military Reservation, P-67 Radar Station, .25 mile north of Dickman Road, east of Clark Road, Battle Creek, Calhoun County, MI

  1. Radar Mosaic of Africa

    NASA Technical Reports Server (NTRS)

    1999-01-01

    This is an image of equatorial Africa, centered on the equator at longitude 15degrees east. This image is a mosaic of almost 4,000 separate images obtained in 1996 by the L-band imaging radar onboard the Japanese Earth Resources Satellite. Using radar to penetrate the persistent clouds prevalent in tropical forests, the Japanese Earth Resources Satellite was able for the first time to image at high resolution this continental scale region during single flooding seasons. The area shown covers about 7.4 million square kilometers (2.8 million square miles) of land surface, spans more than 5,000 kilometers(3,100 miles) east and west and some 2,000 kilometers (1,240 miles) north and south. North is up in this image. At the full resolution of the mosaic (100 meters or 330 feet), this image is more than 500 megabytes in size, and was processed from imagery totaling more than 60 gigabytes.

    Central Africa was imaged twice in 1996, once between January and March, which is the major low-flood season in the Congo Basin, and once between October and November, which is the major high-flood season in the Congo Basin. The red color corresponds to the data from the low-flood season, the green to the high-flood season, and the blue to the 'texture' of the low-flood data. The forests appear green as a result, the flooded and palm forests, as well as urban areas, appear yellow, the ocean and lakes appear black, and savanna areas appear blue, black or green, depending on the savanna type, surface topography and other factors. The areas of the image that are black and white were mapped only between January and March 1996. In these areas, the black areas are savanna or open water, the gray are forests, and the white areas are flooded forests or urban areas. The Congo River dominates the middle of the image, where the nearby forests that are periodically flooded by the Congo and its tributaries stand out as yellow. The Nile River flows north from Lake Victoria in the middle right of

  2. Coseismic and post-seismic deformation fields mapped using satellite radar interferometry and fault slip inversion of the 2015 Mw8.3 Illapel earthquake, Chile

    NASA Astrophysics Data System (ADS)

    Chunyan, Qu; Ronghu, Zuo; XinJian, Shan; Guohong, Zhang; Yingfeng, Zhang; Xiaogang, Song; Yunhua, Liu; Guifang, Zhang

    2017-02-01

    We analyzed Sentinel-1A (S1A)/IW satellite descending data from multiple acquisitions to map coseismic and post-seismic deformation fields and invert the fault slip and afterslip models associated with the seismic moment magnitude (Mw)8.3 earthquake that occurred at Illapel, Chile, on September 16th, 2015. We generated one coseismic and four post-seismic interferograms to analyze temporal and spatial variations in the deformation field after the mainshock; we found that the coseismic deformation field has a semicircular shape and covers a 300-km long and 190-km wide area. The maximum displacement reaches ca. 1.33 m in the LOS subsidence direction, while post-seismic deformation derived from four interferograms with different time intervals is mainly distributed within a long narrow area approximately 65 km wide. Maximum displacement is ca. 8 cm, including two regions of line of sight (LOS) uplift and sinking. Major regions of deformation exhibit opposite directions to the mainshock just after the event, before reverting to consistency. We inverted the coseismic fault slip and afterslip models based on a shallow-dip single fault plane in a homogeneous elastic half space. Our inversion suggests that coseismic slip is mainly concentrated in a shallow region to the northwest of the source, and that rupture length along strike is close to 340 km, with a maximum slip of about 8.16 m to the trench. The estimated moment is 3.126 × 1021 N m (Mw8.27), and the maximum rupture depth is 50 km. Inverted residual slip also shows just one region of slip in the shallow subsurface, which is shifted slightly to the south. In the early stage of deformation, the residual is along the down-dip direction, with a maximum value of ca. 32 cm, before turning into the up-dip direction, with a maximum value of ca. 23 cm. Finally, we present a preliminary analysis of these complex changes in space and time.

  3. Historical sketch: Radar geology

    NASA Technical Reports Server (NTRS)

    Macdonald, H.

    1980-01-01

    A chronological assessment is given of the broad spectra of technology associated with radar geology. Particular attention is given to the most recent developments made in the areas of microwave Earth resources applications and geologic remote sensing from aircraft and satellite. The significance of space derived radar in geologic investigations is discussed and the scientific basis for exploiting the sensitivity of radar signals to various aspects of geologic terrain is given.

  4. Radar sensor for an autonomous Antarctic explorer

    NASA Astrophysics Data System (ADS)

    Foessel, Alex; Apostolopoulos, Dimi; Whittaker, William L.

    1999-01-01

    The localization and identification of antarctic meteorites is a task of great scientific interest and with implications to planetary exploration. Autonomous search for antarctic meteorites presents a profound technical challenge. Ground Penetrating Radar (GPR) holds the prospect to safeguard antarctic robot from terrain dangers and detect subsurface objects. In January 1998, we validated a 500 MHz GPR sensor as part of a field robotic technology demonstration at Patriot Hills, Antarctica. We deployed the sensor from a sled and integrate with position and attitude instruments to perform field measurements. Data was acquired under different conditions and in multiple locations. The radar detected hidden crevasses from 50 cm. distance, thus showing its merit as a rover safeguarding device. It also localized 5 cm. rocks ins now and ice. Moreover, the radar data was used to characterize snow/ice/bedrock stratigraphy. GPR position measurements enabled ground truth and mapping of the location of hazards and interesting subsurface objects and features.

  5. Mercury radar imaging: evidence for polar ice.

    PubMed

    Slade, M A; Butler, B J; Muhleman, D O

    1992-10-23

    The first unambiguous full-disk radar mapping of Mercury at 3.5-centimeter wavelength, with the Goldstone 70-meter antenna transmitting and 26 antennas of the Very Large Array receiving, has provided evidence for the presence of polar ice. The radar experiments, conducted on 8 and 23 August 1991, were designed to image the half of Mercury not photographed by Mariner 10. The orbital geometry allowed viewing beyond the north pole of Mercury; a highly reflective region was clearly visible on the north pole during both experiments. This polar region has areas in which the circular polarization ratio (pt) was 1.0 to 1.4; values < approximately 0.1 are typical for terrestrial planets. Such high values of have hitherto been observed in radar observations only from icy regions of Mars and icy outer planet satellites.

  6. To See the Unseen: A History of Planetary Radar Astronomy

    NASA Technical Reports Server (NTRS)

    Butrica, Andrew J.

    1996-01-01

    -based facilities by this transformed planetary radar astronomy, as well as the upgrading of the Arecibo and Goldstone radars. A technical essay appended to this book provides an overview of planetary radar techniques, especially range-Doppler mapping.

  7. Applications of radar imagery to arctic and subarctic problems

    NASA Technical Reports Server (NTRS)

    Cannon, P. J.

    1980-01-01

    Radar imagery provides year around data acquisition of areas in the Arctic and the Subarctic. The foremost factor influencing the choice of radar imagery as the major data source was the demand for neotric data. The weather is so adverse in parts of Alaska that radar imagery was the only remote sensing technique which could meet the demand. The major map products derived from radar imagery are landform maps and lineament maps. These maps are used to make environmental assessments of areas and to reconstruct the geomorphic history of certain regions or features. Since radar imagery provides information about geologic structure and geomorphic features, it can be used to determine the relationship which exists between geologic structure and geomorphology. Important geologic information related to surface roughness can be obtained through a dry snow cover. Radar imagery is the only remote sensing technique which can provide information needed about sea ice through a cloud cover and dry snow, during strong wind conditions, and throughout the Arctic night.

  8. User guide to the Magellan synthetic aperture radar images

    NASA Technical Reports Server (NTRS)

    Wall, Stephen D.; Mcconnell, Shannon L.; Leff, Craig E.; Austin, Richard S.; Beratan, Kathi K.; Rokey, Mark J.

    1995-01-01

    The Magellan radar-mapping mission collected a large amount of science and engineering data. Now available to the general scientific community, this data set can be overwhelming to someone who is unfamiliar with the mission. This user guide outlines the mission operations and data set so that someone working with the data can understand the mapping and data-processing techniques used in the mission. Radar-mapping parameters as well as data acquisition issues are discussed. In addition, this user guide provides information on how the data set is organized and where specific elements of the set can be located.

  9. Radar illusion via metamaterials

    NASA Astrophysics Data System (ADS)

    Jiang, Wei Xiang; Cui, Tie Jun

    2011-02-01

    An optical illusion is an image of a real target perceived by the eye that is deceptive or misleading due to a physiological illusion or a specific visual trick. The recently developed metamaterials provide efficient approaches to generate a perfect optical illusion. However, all existing research on metamaterial illusions has been limited to theory and numerical simulations. Here, we propose the concept of a radar illusion, which can make the electromagnetic (EM) image of a target gathered by radar look like a different target, and we realize a radar illusion device experimentally to change the radar image of a metallic target into a dielectric target with predesigned size and material parameters. It is well known that the radar signatures of metallic and dielectric objects are significantly different. However, when a metallic target is enclosed by the proposed illusion device, its EM scattering characteristics will be identical to that of a predesigned dielectric object under the illumination of radar waves. Such an illusion device will confuse the radar, and hence the real EM properties of the metallic target cannot be perceived. We designed and fabricated the radar illusion device using artificial metamaterials in the microwave frequency, and good illusion performances are observed in the experimental results.

  10. Metamaterial for Radar Frequencies

    DTIC Science & Technology

    2012-09-01

    Circuit Board RAM Radar Absorbing Material RCS Radar Cross Section SNR Signal-to-Noise Ratio SNG Single-Negative SRR Split Ring Resonator...although some can be single-negative ( SNG ). DNG refers to material with simultaneous negative real parts of the permittivity r  and permeability

  11. Synchronization in multistatic radar

    NASA Astrophysics Data System (ADS)

    Jubrink, H. G.

    1993-08-01

    This report gives a summary of multistatic radar principles and synchronization methods. Different methods are described using direct and indirect synchronization. The report also presents a general review of synchronization methods for the future. Two LORAN C receivers have been analyzed for use as local reference oscillators in multistatic radar.

  12. The PROUST radar

    NASA Technical Reports Server (NTRS)

    Bertin, F.; Glass, M.; Ney, R.; Petitdidier, M.

    1986-01-01

    The Stratosphere-Troposphere (ST) radar called PROUST works at 935 MHz using the same klystron and antenna as the coherent-scatter radar. The use of this equipment for ST work has required some important modifications of the transmitting system and the development of receiving, data processing and acquisition (1984,1985) equipment. The modifications are discussed.

  13. Noncooperative rendezvous radar system

    NASA Technical Reports Server (NTRS)

    1974-01-01

    A fire control radar system was developed, assembled, and modified. The baseline system and modified angle tracking system are described along with the performance characteristics of the baseline and modified systems. Proposed changes to provide additional techniques for radar evaluation are presented along with flight test data.

  14. Polarization Radar Processing Technology

    DTIC Science & Technology

    1989-10-01

    Oi"C FILE ( J qII RADC-TR-89-144 In-House Report October 1989 AD-A215 242 POLARIZATION RADAR PROCESSING TECHNOLOGY Kenneth C. Stiefvater, Russell D...NO. NO. NO. ACCESSION NO. 62702F 4506 11 58 11. TITLE (Include Security Classification) POLARIZATION RADAR PROCESSING TECHNOLOGY 12. PERSONAL AUTHOR(S

  15. Determination of radar MTF

    SciTech Connect

    Chambers, D.

    1994-11-15

    The ultimate goal of the Current Meter Array (CMA) is to be able to compare the current patterns detected with the array with radar images of the water surface. The internal wave current patterns modulate the waves on the water surface giving a detectable modulation of the radar cross-section (RCS). The function relating the RCS modulations to the current patterns is the Modulation Transfer Function (MTF). By comparing radar images directly with co-located CMA measurements the MTF can be determined. In this talk radar images and CMA measurements from a recent experiment at Loch Linnhe, Scotland, will be used to make the first direct determination of MTF for an X and S band radar at low grazing angles. The technical problems associated with comparing radar images to CMA data will be explained and the solution method discussed. The results suggest the both current and strain rate contribute equally to the radar modulation for X band. For S band, the strain rate contributes more than the current. The magnitude of the MTF and the RCS modulations are consistent with previous estimates when the wind is blowing perpendicular to the radar look direction.

  16. Equatorial MU Radar project

    NASA Astrophysics Data System (ADS)

    Yamamoto, Mamoru; Hashiguchi, H.; Tsuda, Toshitaka; Yamamoto, Masayuki

    Research Institute for Sustainable Humanosphere, Kyoto University (RISH) has been studying the atmosphere by using radars. The first big facility was the MU (Middle and Upper atmosphere) radar installed in Shiga, Japan in 1984. This is one of the most powerful and multi-functional radar, and is successful of revealing importance of atmospheric waves for the dynamical vertical coupling processes. The next big radar was the Equatorial Atmosphere Radar (EAR) installed at Kototabang, West Sumatra, Indonesia in 2001. The EAR was operated under close collaboration with LAPAN (Indonesia National Institute for Aeronautics and Space), and conducted the long-term continuous observations of the equatorial atmosphere/ionosphere for more than 10 years. The MU radar and the EAR are both utilized for inter-university and international collaborative research program for long time. National Institute for Polar Research (NIPR) joined EISCAT Scientific Association together with Nagoya University, and developed the PANSY radar at Syowa base in Antarctica as a joint project with University of Tokyo. These are the efforts of radar study of the atmosphere/ionosphere in the polar region. Now we can find that Japan holds a global network of big atmospheric/ionospheric radars. The EAR has the limitation of lower sensitivity compared with the other big radars shown above. RISH now proposes a plan of Equatorial MU Radar (EMU) that is to establish the MU-radar class radar next to the EAR. The EMU will have an active phased array antenna with the 163m diameter and 1055 cross-element Yagis. Total output power of the EMU will be more than 500kW. The EMU can detect turbulent echoes from the mesosphere (60-80km). In the ionosphere incoherent-scatter observations of plasma density, drift, and temperature would be possible. Multi-channel receivers will realize radar-imaging observations. The EMU is one of the key facilities in the project "Study of coupling processes in the solar-terrestrial system

  17. Spaceborne weather radar

    NASA Technical Reports Server (NTRS)

    Meneghini, Robert; Kozu, Toshiaki

    1990-01-01

    The present work on the development status of spaceborne weather radar systems and services discusses radar instrument complementarities, the current forms of equations for the characterization of such aspects of weather radar performance as surface and mirror-image returns, polarimetry, and Doppler considerations, and such essential factors in spaceborne weather radar design as frequency selection, scanning modes, and the application of SAR to rain detection. Attention is then given to radar signal absorption by the various atmospheric gases, rain drop size distribution and wind velocity determinations, and the characteristics of clouds, as well as the range of available estimation methods for backscattering, single- and dual-wavelength attenuation, and polarimetric and climatological characteristics.

  18. Micropower impulse radar imaging

    SciTech Connect

    Hall, M.S.

    1995-11-01

    From designs developed at the Lawrence Livermore National Laboratory (LLNL) in radar and imaging technologies, there exists the potential for a variety of applications in both public and private sectors. Presently tests are being conducted for the detection of buried mines and the analysis of civil structures. These new systems use a patented ultra-wide band (impulse) radar technology known as Micropower Impulse Radar (GPR) imaging systems. LLNL has also developed signal processing software capable of producing 2-D and 3-D images of objects embedded in materials such as soil, wood and concrete. My assignment while at LLNL has focused on the testing of different radar configurations and applications, as well as assisting in the creation of computer algorithms which enable the radar to scan target areas of different geometeries.

  19. Intelligent radar data processing

    NASA Astrophysics Data System (ADS)

    Holzbaur, Ulrich D.

    The application of artificial intelligence principles to the processing of radar signals is considered theoretically. The main capabilities required are learning and adaptation in a changing environment, processing and modeling information (especially dynamics and uncertainty), and decision-making based on all available information (taking its reliability into account). For the application to combat-aircraft radar systems, the tasks include the combination of data from different types of sensors, reacting to electronic counter-countermeasures, evaluation of how much data should be acquired (energy and radiation management), control of the radar, tracking, and identification. Also discussed are related uses such as monitoring the avionics systems, supporting pilot decisions with respect to the radar system, and general applications in radar-system R&D.

  20. 4. VIEW NORTHEAST, radar tower (unknown function), prime search radar ...

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

    4. VIEW NORTHEAST, radar tower (unknown function), prime search radar tower, emergency power building, and height finder radar tower - Fort Custer Military Reservation, P-67 Radar Station, .25 mile north of Dickman Road, east of Clark Road, Battle Creek, Calhoun County, MI

  1. 5. VIEW EAST, height finder radar towers, radar tower (unknown ...

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

    5. VIEW EAST, height finder radar towers, radar tower (unknown function), prime search radar tower, operations building, and central heating plant - Fort Custer Military Reservation, P-67 Radar Station, .25 mile north of Dickman Road, east of Clark Road, Battle Creek, Calhoun County, MI

  2. Radar observations of a volcanic terrain: Askja Caldera, Iceland

    NASA Technical Reports Server (NTRS)

    Evans, D. L.

    1978-01-01

    Surface roughness spectra of nine radar backscatter units in the Askja caldera region of Iceland were predicted from computer-enhanced like- and cross-polarized radar images. A field survey of the caldera was then undertaken to check the accuracy of the preliminary analysis. There was good agreement between predicted surface roughness of backscatter units and surface roughness observed in the field. In some cases, variations in surface roughness could be correlated with previously mapped geologic units.

  3. Tomographic Processing of Synthetic Aperture Radar Signals for Enhanced Resolution

    DTIC Science & Technology

    1989-11-01

    digital signal processing view of strip-mapping synthetic aperture radar," M.S. thesis , University of Illinois, Urbana, IL,1988." [571 David C. Munson...TOMOGRAPHIC PROCESSING OF 1 SYNTHETIC APERTURE I RADAR SIGNALS FOR ENHANCED RESOLUTION,I * Jerald Lee Bauck DTIC ELECTE JAN2419901D I I UNIVERSITY OF ILLINOIS...NC 27709-2211 ELEMENT NO. NO. NO CCESSION NO. 11i. TITLE (Include Security Classification) TOMOGRAPHIC PROCESSING OF SYNTHETIC APERTURE RADlAR SIGNALS

  4. Spaceborne radar observations: A guide for Magellan radar-image analysis

    NASA Technical Reports Server (NTRS)

    Ford, J. P.; Blom, R. G.; Crisp, J. A.; Elachi, Charles; Farr, T. G.; Saunders, R. Stephen; Theilig, E. E.; Wall, S. D.; Yewell, S. B.

    1989-01-01

    Geologic analyses of spaceborne radar images of Earth are reviewed and summarized with respect to detecting, mapping, and interpreting impact craters, volcanic landforms, eolian and subsurface features, and tectonic landforms. Interpretations are illustrated mostly with Seasat synthetic aperture radar and shuttle-imaging-radar images. Analogies are drawn for the potential interpretation of radar images of Venus, with emphasis on the effects of variation in Magellan look angle with Venusian latitude. In each landform category, differences in feature perception and interpretive capability are related to variations in imaging geometry, spatial resolution, and wavelength of the imaging radar systems. Impact craters and other radially symmetrical features may show apparent bilateral symmetry parallel to the illumination vector at low look angles. The styles of eruption and the emplacement of major and minor volcanic constructs can be interpreted from morphological features observed in images. Radar responses that are governed by small-scale surface roughness may serve to distinguish flow types, but do not provide unambiguous information. Imaging of sand dunes is rigorously constrained by specific angular relations between the illumination vector and the orientation and angle of repose of the dune faces, but is independent of radar wavelength. With a single look angle, conditions that enable shallow subsurface imaging to occur do not provide the information necessary to determine whether the radar has recorded surface or subsurface features. The topographic linearity of many tectonic landforms is enhanced on images at regional and local scales, but the detection of structural detail is a strong function of illumination direction. Nontopographic tectonic lineaments may appear in response to contrasts in small-surface roughness or dielectric constant. The breakpoint for rough surfaces will vary by about 25 percent through the Magellan viewing geometries from low to high

  5. Evaluation of Various Radar Data Quality Control Algorithms Based on Accumulated Radar Rainfall Statistics

    NASA Technical Reports Server (NTRS)

    Robinson, Michael; Steiner, Matthias; Wolff, David B.; Ferrier, Brad S.; Kessinger, Cathy; Einaudi, Franco (Technical Monitor)

    2000-01-01

    The primary function of the TRMM Ground Validation (GV) Program is to create GV rainfall products that provide basic validation of satellite-derived precipitation measurements for select primary sites. A fundamental and extremely important step in creating high-quality GV products is radar data quality control. Quality control (QC) processing of TRMM GV radar data is based on some automated procedures, but the current QC algorithm is not fully operational and requires significant human interaction to assure satisfactory results. Moreover, the TRMM GV QC algorithm, even with continuous manual tuning, still can not completely remove all types of spurious echoes. In an attempt to improve the current operational radar data QC procedures of the TRMM GV effort, an intercomparison of several QC algorithms has been conducted. This presentation will demonstrate how various radar data QC algorithms affect accumulated radar rainfall products. In all, six different QC algorithms will be applied to two months of WSR-88D radar data from Melbourne, Florida. Daily, five-day, and monthly accumulated radar rainfall maps will be produced for each quality-controlled data set. The QC algorithms will be evaluated and compared based on their ability to remove spurious echoes without removing significant precipitation. Strengths and weaknesses of each algorithm will be assessed based on, their abilit to mitigate both erroneous additions and reductions in rainfall accumulation from spurious echo contamination and true precipitation removal, respectively. Contamination from individual spurious echo categories will be quantified to further diagnose the abilities of each radar QC algorithm. Finally, a cost-benefit analysis will be conducted to determine if a more automated QC algorithm is a viable alternative to the current, labor-intensive QC algorithm employed by TRMM GV.

  6. Surface contour radar observations of the directional wave spectrum during Fasinex

    NASA Technical Reports Server (NTRS)

    Walsh, E. J.; Hancock, D. W., III; Hines, D. E.; Swift, R. N.; Scott, J. F.

    1988-01-01

    The surface control radar (SCR), a 36-GHz computer-controlled airborne radar which generates a false-color coded elevation map of the sea surface below the aircraft in real time, is described. The SCR turned out to be ideal for documenting the wave spectra during Fasinex (the Frontal Air-Sea Interaction Experiment) due to its high spatial resolution and rapid mapping capability over extensive areas. Synoptic weather maps for February 15-18, 1986 are presented.

  7. Radar remote sensing in biology

    USGS Publications Warehouse

    Moore, Richard K.; Simonett, David S.

    1967-01-01

    The present status of research on discrimination of natural and cultivated vegetation using radar imaging systems is sketched. The value of multiple polarization radar in improved discrimination of vegetation types over monoscopic radars is also documented. Possible future use of multi-frequency, multi-polarization radar systems for all weather agricultural survey is noted.

  8. NASA's DC-8 With Rain Mapping Radar

    NASA Technical Reports Server (NTRS)

    1999-01-01

    In a joint venture between NASA and Japan's NASDA, scientists have been using satellites, airplanes, and boats to measure rain physics in and under thunderstorms over open water. This Quick Time movie shows the ER-2, a high altitude reconnaissance aircraft equipped with 8 lightening detectors and other instruments used to study hurricanes and thunderstorms. Earth science and weather studies are an important ongoing function of NASA and its affiliates.

  9. Mapping diverse vegetation with multichannel radar images

    NASA Technical Reports Server (NTRS)

    Ford, J. P.; Wickland, D. E.; Ocampo, A.; Sharitz, R. R.

    1986-01-01

    Airborne-SAR, SIR-A, Seasat SAR, and Landsat TM images of the Savannah River Plant, a gently sloping area of South Carolina covered with diverse vegetation, are presented and briefly characterized. Preliminary results indicate that multiple-polarization images constructed from the airborne-SAR data give some indication of forest density and understory growth but do not permit discrimination between evergreen and deciduous forests. Heat-tolerant vegetation growing on sand bars in streams bearing thermal effluents from nuclear reactors on the site is found to have a distinguishing polarization signature.

  10. Imaging Radar Applications in the Death Valley Region

    NASA Technical Reports Server (NTRS)

    Farr, Tom G.

    1996-01-01

    Death Valley has had a long history as a testbed for remote sensing techniques (Gillespie, this conference). Along with visible-near infrared and thermal IR sensors, imaging radars have flown and orbited over the valley since the 1970's, yielding new insights into the geologic applications of that technology. More recently, radar interferometry has been used to derive digital topographic maps of the area, supplementing the USGS 7.5' digital quadrangles currently available for nearly the entire area. As for their shorter-wavelength brethren, imaging radars were tested early in their civilian history in Death Valley because it has a variety of surface types in a small area without the confounding effects of vegetation. In one of the classic references of these early radar studies, in a semi-quantitative way the response of an imaging radar to surface roughness near the radar wavelength, which typically ranges from about 1 cm to 1 m was explained. This laid the groundwork for applications of airborne and spaceborne radars to geologic problems in and regions. Radar's main advantages over other sensors stems from its active nature- supplying its own illumination makes it independent of solar illumination and it can also control the imaging geometry more accurately. Finally, its long wavelength allows it to peer through clouds, eliminating some of the problems of optical sensors, especially in perennially cloudy and polar areas.

  11. Covert situational awareness with handheld ultrawideband short-pulse radar

    NASA Astrophysics Data System (ADS)

    Barnes, Mark A.; Nag, Soumya; Payment, Tim

    2001-08-01

    Law enforcement and emergency services all face the difficult task of determining the locations of people within a building. A handheld radar able to detect motion through walls and other obstructions has been developed to fill this need. This paper describes the attributes and difficulties of the radar design and includes test results of the radar's performance. This discussion begins by summarizing key user requirements and the electromagnetic losses of typical building materials. Ultra-wideband (UWB) short pulse radars are well suited for a handheld sensor primarily because of their inherit time isolation in high clutter environments and their capability to achieve high resolution at low spectral center frequencies. There are also constraints that complicate the system design. Using a technique referred to as time-modulation allows the radars to reject range ambiguities and enhances electromagnetic compatibility with similar radars and ambient systems. An outline of the specifications of the radar developed and a process diagram on how it generates a motion map showing range and direction of the people moving within structures is included. Images are then presented to illustrate its performance. The images include adults, child, and a dog. The test results also include data showing the radar's performance through a variety of building materials.

  12. Spaceborne meteorological radar studies

    NASA Technical Reports Server (NTRS)

    Meneghini, R.

    1988-01-01

    Various radar designs and methods are studied for the estimation of rainfall parameters from space. An immediate goal is to support the development of the spaceborne radar that has been proposed for the Tropical Rain Measuring Mission (TRMM). The effort is divided into two activities: a cooperative airborne rain measuring experiment with the Radio Research Laboratory of Japan (RRL), and the modelling of spaceborne weather radars. An airborne rain measuring experiment was conducted at Wallops Flight Facility in 1985 to 1986 using the dual-wavelength radar/radiometer developed by RRL. The data are presently being used to test a number of methods that are relevant to spaceborne weather radars. An example is shown of path-averaged rain rates as estimated from three methods: the standard reflectivity rain rate method (Z-R), a dual-wavelength method, and a surface reference method. The results from the experiment shows for the first time the feasibility of using attenuation methods from space. The purposes of the modelling are twofold: to understand in a quantitative manner the relationships between a particular radar design and its capability for estimating precipitation parameters and to help devise and test new methods. The models are being used to study the impact of various TRMM radar designs on the accuracy of rain rate estimation as well as to test the performance of range-profiling algorithms, the mirror-image method, and some recently devised graphical methods for the estimation of the drop size distribution.

  13. Radar applications overview

    NASA Astrophysics Data System (ADS)

    Greenspan, Marshall

    1996-06-01

    During the fifty years since its initial development as a means of providing early warning of airborne attacks against allied countries during World War II, radar systems have developed to the point of being highly mobile and versatile systems capable of supporting a wide variety of remote sensing applications. Instead of being tied to stationary land-based sites, radar systems have found their way into highly mobile land vehicles as well as into aircraft, missiles, and ships of all sizes. Of all these applications, however, the most exciting revolution has occurred in the airborne platform arena where advanced technology radars can be found in all shapes and sizes...ranging from the large AWACS and Joint STARS long range surveillance and targeting systems to small millimeter wave multi-spectral sensors on smart weapons that can detect and identify their targets through the use of highly sophisticated digital signal processing hardware and software. This paper presents an overview of these radar applications with the emphasis on modern airborne sensors that span the RF spectrum. It will identify and describe the factors that influence the parameters of low frequency and ultra wide band radars designed to penetrate ground and dense foliage environments and locate within them buried mines, enemy armor, and other concealed or camouflaged weapons of war. It will similarly examine the factors that lead to the development of airborne radar systems that support long range extended endurance airborne surveillance platforms designed to detect and precision-located both small high speed airborne threats as well as highly mobile time critical moving and stationary surface vehicles. The mission needs and associated radar design impacts will be contrasted with those of radar systems designed for high maneuverability rapid acquisition tactical strike warfare platforms, and shorter range cued air-to-surface weapons with integral smart radar sensors.

  14. Radar frequency radiation

    NASA Astrophysics Data System (ADS)

    Malowicki, E.

    1981-11-01

    A method is presented for the determination of radar frequency radiation power densities that the PAVE PAWS radar system could produce in its air and ground environment. The effort was prompted by the concern of the people in the vicinity of OTIS AFB MA and BEALE AFB CA about the possible radar frequency radiation hazard of the PAVE PAWS radar. The method is based on the following main assumptions that: (a) the total field can be computed as the vector summation of the individual fields due to each antenna element; (b) the individual field can be calculated using distances for which the field point is in the far field of the antenna element. An RFR computer program was coded for the RADC HE 6180 digital computer and exercised to calculate the radiation levels in the air and ground space for the present baseline and the possible Six DB and 10 DB growth systems of the PAVE PAWS radar system at OTIS AFB MA. The average radiation levels due to the surveillance fence were computed for three regions: in the air space in front of the radar, at the radar hazard fence at OTIS AFB MA and at representative ground points in the OTIS AFB vicinity. It was concluded that the radar frequency radiation of PAVE PAWS does not present a hazard to personnel provided there is no entry to the air hazard zone or to the area within the hazard fence. The method developed offers a cost effective way to determine radiation levels from a phased array radar especially in the near field and transition regions.

  15. Space Radar Image of Manaus, Brazil

    NASA Technical Reports Server (NTRS)

    1999-01-01

    These two images were created using data from the Spaceborne Imaging Radar-C/X-Band Synthetic Aperture Radar (SIR-C/X-SAR). On the left is a false-color image of Manaus, Brazil acquired April 12, 1994, onboard space shuttle Endeavour. In the center of this image is the Solimoes River just west of Manaus before it combines with the Rio Negro to form the Amazon River. The scene is around 8 by 8 kilometers (5 by 5 miles) with north toward the top. The radar image was produced in L-band where red areas correspond to high backscatter at HH polarization, while green areas exhibit high backscatter at HV polarization. Blue areas show low backscatter at VV polarization. The image on the right is a classification map showing the extent of flooding beneath the forest canopy. The classification map was developed by SIR-C/X-SAR science team members at the University of California,Santa Barbara. The map uses the L-HH, L-HV, and L-VV images to classify the radar image into six categories: Red flooded forest Green unflooded tropical rain forest Blue open water, Amazon river Yellow unflooded fields, some floating grasses Gray flooded shrubs Black floating and flooded grasses Data like these help scientists evaluate flood damage on a global scale. Floods are highly episodic and much of the area inundated is often tree-covered. Spaceborne Imaging Radar-C and X-Synthetic Aperture Radar (SIR-C/X-SAR) is part of NASA's Mission to Planet Earth. The radars illuminate Earth with microwaves allowing detailed observations at any time, regardless of weather or sunlight conditions. SIR-C/X-SAR uses three microwave wavelengths: L-band (24 cm), C-band (6 cm) and X-band (3 cm). The multi-frequency data will be used by the international scientific community to better understand the global environment and how it is changing. The SIR-C/X-SAR data, complemented by aircraft and ground studies, will give scientists clearer insights into those environmental changes which are caused by nature and those

  16. Gulf of Mexico satellite radar altimetry

    NASA Technical Reports Server (NTRS)

    Parra, C. G.; Forsythe, R. G.; Parsons, C. L.

    1981-01-01

    The dynamic topography of the sea surface was measured. The radar altimeter measurements yield average ocean topographic data which are mapped. Seasonal deviations from a 3 year mean topography are presented. The altimeters are also instrumented with sample and hold gates which provide information about the shape and amplitude of the return waveform. Parameters including ocean surface wind speed and the significant wave height are determined. One hundred eighty six wind speed and significant wave height histograms are presented.

  17. A microprogrammable radar controller

    NASA Technical Reports Server (NTRS)

    Law, D. C.

    1986-01-01

    The Wave Propagation Lab. has completed the design and construction of a microprogrammable radar controller for atmospheric wind profiling. Unlike some radar controllers using state machines or hardwired logic for radar timing, this design is a high speed programmable sequencer with signal processing resources. A block diagram of the device is shown. The device is a single 8 1/2 inch by 10 1/2 inch printed circuit board and consists of three main subsections: (1) the host computer interface; (2) the microprogram sequencer; and (3) the signal processing circuitry. Each of these subsections are described in detail.

  18. Radar investigation of asteroids

    NASA Technical Reports Server (NTRS)

    Ostro, S. J.

    1981-01-01

    Efforts were focused on: (1) acquisition of radar data at Arecibo; (2) examination of raw data; (3) reduction of the unmodulated data to background-free, calibrated spectra; (4) integration and coherent analyses of the phase-coded data; and (5) calculation of Doppler shifts and preliminary values for echo limb-to-limb bandwidths, radar cross sections, and circular polarization ratios. Asteroids observed to data have radar properties distinct from those of the rocky terrestrial planets and those of the icy Galilean satellites.

  19. Radar investigation of asteroids

    NASA Technical Reports Server (NTRS)

    Ostro, S. J.

    1981-01-01

    Software to support all stages of asteroid radar observation and data analysis is developed. First-order analysis of all data in hand is complete. Estimates of radar cross sections, circular polarization ratios, and limb-to-limb echo spectral bandwidths for asteroids 7 Iris, 16 Psyche, 97 Klotho, 1862 Apollo, and 1915 Quetzalcoatl are reported. Radar observations of two previously unobserved asteroids were conducted. An Aten asteroid, 2100 Ra-Shalom, with the smallest known semimajor axis (0.83) was detected. Preliminary data reduction indicates a circular polarization ratio comparable to those of Apollo, Quetzalcoatl, and Toro.

  20. Radar investigation of asteroids

    NASA Technical Reports Server (NTRS)

    Ostro, S. J.

    1984-01-01

    The initial radar observations of the mainbelt asteroids 9 Metis, 27 Euterpe, and 60 Echo are examined. For each target, data are taken simultaneously in the same sense of circular polarization as transmitted as well as in the opposite (OC) sense. Estimates of the radar cross sections provide estimates of the circular polarization ratio, and the normalized OC radar cross section. The circular polarization ratio, is comparable to values measured for other large S type asteroids and for a few much smaller, Earth approaching objects, most of the echo is due to single reflection backscattering from smooth surface elements.

  1. Radar investigation of asteroids

    NASA Astrophysics Data System (ADS)

    Ostro, S. J.

    1981-11-01

    Software to support all stages of asteroid radar observation and data analysis is developed. First-order analysis of all data in hand is complete. Estimates of radar cross sections, circular polarization ratios, and limb-to-limb echo spectral bandwidths for asteroids 7 Iris, 16 Psyche, 97 Klotho, 1862 Apollo, and 1915 Quetzalcoatl are reported. Radar observations of two previously unobserved asteroids were conducted. An Aten asteroid, 2100 Ra-Shalom, with the smallest known semimajor axis (0.83) was detected. Preliminary data reduction indicates a circular polarization ratio comparable to those of Apollo, Quetzalcoatl, and Toro.

  2. Studies on Radar Sensor Networks

    DTIC Science & Technology

    2007-08-08

    through-foliage target detection using UWB radar sensor network based on real-world data; 2. Foliage clutter modeling using UWB radars; 3. Outdoor UWB...channel modeling based on field data; 4. Multi-target detection using radar sensor networks (theoretical studies); 5. SVD-QR and graph theory for MIMO...Superimposed code based channel assignment in multi-radio multi-channel wireless mesh networks. 15. SUBJECT TERMS Radar Sensor Network, UWB Radar, Sense

  3. Laser Radar Animation

    NASA Video Gallery

    Laser and radar instruments aboard NASA aircraft provide measurements of the snow and ice surface and down to the bedrock under the ice. Lasers, with a shorter wavelength, measure the surface eleva...

  4. Multispectral imaging radar

    NASA Technical Reports Server (NTRS)

    Porcello, L. J.; Rendleman, R. A.

    1972-01-01

    A side-looking radar, installed in a C-46 aircraft, was modified to provide it with an initial multispectral imaging capability. The radar is capable of radiating at either of two wavelengths, these being approximately 3 cm and 30 cm, with either horizontal or vertical polarization on each wavelength. Both the horizontally- and vertically-polarized components of the reflected signal can be observed for each wavelength/polarization transmitter configuration. At present, two-wavelength observation of a terrain region can be accomplished within the same day, but not with truly simultaneous observation on both wavelengths. A multiplex circuit to permit this simultaneous observation has been designed. A brief description of the modified radar system and its operating parameters is presented. Emphasis is then placed on initial flight test data and preliminary interpretation. Some considerations pertinent to the calibration of such radars are presented in passing.

  5. Radar investigation of asteroids

    NASA Technical Reports Server (NTRS)

    Ostro, S. J.

    1983-01-01

    For 80 Sappho, 356 Liguria, 694 Ekard, and 2340 Hathor, data were taken simultaneously in the same sense of circular polarization as transmitted (SC) as well as in the opposite (OC) sense. Graphs show the average OC and SC radar echo power spectra soothed to a resolution of EFB Hz and plotted against Doppler frequency. Radar observations of the peculiar object 2201 Oljato reveal an unusual set of echo power spectra. The albedo and polarization ratio remain fairly constant but the bandwidths range from approximately 0.8 Hz to 1.4 Hz and the spectral shapes vary dramatically. Echo characteristics within any one date's approximately 2.5-hr observation period do not fluctuate very much. Laboratory measurements of the radar frequency electrical properties of particulate metal-plus-silicate mixtures can be combined with radar albedo estimates to constrain the bulk density and metal weight, fraction in a hypothetical asteroid regolith having the same particle size distribution as lab samples.

  6. Space radar image of Galeras Volcano, Colombia

    NASA Technical Reports Server (NTRS)

    1995-01-01

    This radar image of the area surrounding the Galeras volcano in southern Colombia shows the ability of a multi-frequency radar to map volcanic structures that can be dangerous to study on the ground. Galeras has erupted more than 20 times since the area was first visited by European explorers in the 1500s. Volcanic activity levels have been high in the last five years, including an eruption in January 1993 that killed nine people on a scientific expedition to the volcano summit. Galeras is the light green area near the center of the image. The active cone, with a small summit pit, is the red feature nestled against the lower right edge of the caldera (crater) wall. The city of Pasto, with a population of 300,000, is shown in orange near the bottom of the image, just 8 kilometers (5 miles) from the volcano. The image was acquired by the Spaceborne Imaging Radar-C/X-Band Synthetic Aperture Radar (SIR-C/ X-SAR) aboard the space shuttle Endeavour on its 96th orbit on April 15, 1994. North is toward the upper right. The area shown is 49.1 by 36.0 kilometers (30.5 by 22.3 miles), centered at 1.2 degrees north latitude and 77.4 degrees west longitude. The radar illumination is from the top of the image. The false colors in this image were created using the following radar channels: red represents the L-band (horizontally transmitted and received); green represents the L-band (horizontally transmitted, vertically received); blue represents the C-band (horizontally transmitted, vertically received). Galeras is one of 15 volcanoes worldwide that are being monitored by the scientific community as an 'International Decade Volcano' because of the hazard that it represents to the local population.

  7. Radar Cross Section Measurements

    DTIC Science & Technology

    1986-09-30

    Radar 54 17. Measured Range Sidelobe Performance of Chirp Radar 56 18. Range and Cross Range Image of Target Dror.’ŕ Vehicle 57 19. Incoherent rms...the measured range resolution, 4.9 in, closely agrees with the theoretical performance for this weighting. The measured range sidelobe performance...Interval 4.89in. 2% kHz 300 kHz 310 kHz (b) Expanded Scale + 5 ft from Target Figure 17. Measured Range Sidelobe Performance of

  8. Downhole pulse radar

    DOEpatents

    Chang, Hsi-Tien

    1987-09-28

    A borehole logging tool generates a fast rise-time, short duration, high peak-power radar pulse having broad energy distribution between 30 MHz and 300 MHz through a directional transmitting and receiving antennas having barium titanate in the electromagnetically active region to reduce the wavelength to within an order of magnitude of the diameter of the antenna. Radar returns from geological discontinuities are sampled for transmission uphole. 7 figs.

  9. Downhole pulse radar

    DOEpatents

    Chang, Hsi-Tien

    1989-01-01

    A borehole logging tool generates a fast rise-time, short duration, high peak-power radar pulse having broad energy distribution between 30 MHz and 300 MHz through a directional transmitting and receiving antennas having barium titanate in the electromagnetically active region to reduce the wavelength to within an order of magnitude of the diameter of the antenna. Radar returns from geological discontinuities are sampled for transmission uphole.

  10. Airborne MIMO GMTI Radar

    DTIC Science & Technology

    2011-03-31

    applications [1], [2], [3], [4]. [5]. [6]. [7]. [8]. [9]. [10]. [11]. [12]. Conventional phased array radars form a single coherent transmit beam and...intentionally left blank. 1. INTRODUCTION Conventional phased - array radars form a single coherent transmit beam and measure the backscattered response... steering vector for a SI MO array with nr"/? receiver phase centers located at positions xm + y„. This is how the MIMO virtual array arises. The waveforms

  11. Customizable Digital Receivers for Radar

    NASA Technical Reports Server (NTRS)

    Moller, Delwyn; Heavey, Brandon; Sadowy, Gregory

    2008-01-01

    Compact, highly customizable digital receivers are being developed for the system described in 'Radar Interferometer for Topographic Mapping of Glaciers and Ice Sheets' (NPO-43962), NASA Tech Briefs, Vol. 31, No. 7 (August 2007), page 72. The receivers are required to operate in unison, sampling radar returns received by the antenna elements in a digital beam-forming (DBF) mode. The design of these receivers could also be adapted to commercial radar systems. At the time of reporting the information for this article, there were no commercially available digital receivers capable of satisfying all of the operational requirements and compact enough to be mounted directly on the antenna elements. A provided figure depicts the overall system of which the digital receivers are parts. Each digital receiver includes an analog-to-digital converter (ADC), a demultiplexer (DMUX), and a field-programmable gate array (FPGA). The ADC effects 10-bit band-pass sampling of input signals having frequencies up to 3.5 GHz. The input samples are demultiplexed at a user-selectable rate of 1:2 or 1:4, then buffered in part of the FPGA that functions as a first-in/first-out (FIFO) memory. Another part of the FPGA serves as a controller for the ADC, DMUX, and FIFO memory and as an interface between (1) the rest of the receiver and (2) a front-panel data port (FPDP) bus, which is an industry-standard parallel data bus that has a high data-rate capability and multichannel configuration suitable for DBF. Still other parts of the FPGA in each receiver perform signal-processing functions. The digital receivers can be configured to operate in a stand-alone mode, or in a multichannel mode as needed for DBF. The customizability of the receiver makes it applicable to a broad range of system architectures. The capability for operation of receivers in either a stand-alone or a DBF mode enables the use of the receivers in an unprecedentedly wide variety of radar systems.

  12. Low level range coverage performance prediction for VHF radar

    NASA Astrophysics Data System (ADS)

    Kuschel, H.

    1989-09-01

    A VHF radar frequencies the range coverage is not strictly limited by the quasi-optical horizon like at microwave radar frequencies but is extended due to diffraction propagation. This effect, here called beyond-the-horizon (BTH) detection capability is strongly dependent on the propagation path and thus on the terrain structure. The availability of digital terrain maps gives way to the use of computerized methods for the prediction of radar range coverage in real environment. In combination with wave propagation models suitable for diffraction at terrain structures, digital terrain data can even be used for the prediction of BTH target detectability at VHF radar. Here the digital landmass system (DLSS) terrain database was used in combination with a multiple-knife-edge diffraction model to predict the diffraction attenuation between the radar and the potential target positions, especially beyond the optical horizon. The propagation paths extracted from the database are modeled as a sequence of diffraction screens suited for the application of a Fresnel-Kirchhoff algorithm yielding the knife-edge-diffraction attenuation. This terrain related propagation model was verified by a large number of measurements at different frequencies. Implemented in a fast computer system, this prediction model can be used for mission planning of air operations. Considering hostile VHF radar coverage and terrain condition for flight path optimization or, on the other hand it can assist in siting mobile radars for gap filling according to the actual threat situation. Calculations of the diffraction propagation using the prediction model, yield range coverage patterns in real terrain situations, allowing to quantify the BTH detection advantage of VHF radar compared to microwave radar. An experimental large wavelength radar LARA (VHF) built flying targets beyond the close horizon. Here, especially the detection of hiding helicopters by exploiting diffractive wave propagation was examined

  13. Land subsidence measured by satellite radar altimetry

    NASA Technical Reports Server (NTRS)

    Krabill, W. B.; Brooks, R. L.

    1981-01-01

    Radar altimeter measurements from the GEOS-3 and SEASAT satellites are being evaluated to assess their potential contribution to terrain mapping. The primary evaluation area is the San Joaquin Valley of southern California; 40,000/sq km of the Valley have been mapped at a contour interval of 10 m from the satellite altimeter measurements. The accuracy of the altimeter derived terrain elevations is being assessed by comparison with 1:24,000 and digitized 1:250,000 maps and by intercomparisons at the crossover altimeter intersections. Comparisons of the altimeter derived elevations with historical maps archived at the U.S. Geological Survey confirms the USGS 1926-1972 subsidence contours for this area. Preliminary results from a similar analysis in the Houston-Galveston area of subsidence also demonstrates a capability of measuring land subsidence by satellite altimetry.

  14. Clutter in the GMTI range-velocity map.

    SciTech Connect

    Doerry, Armin Walter

    2009-04-01

    Ground Moving Target Indicator (GMTI) radar maps echo data to range and range-rate, which is a function of a moving target's velocity and its position within the antenna beam footprint. Even stationary clutter will exhibit an apparent motion spectrum and can interfere with moving vehicle detections. Consequently it is very important for a radar to understand how stationary clutter maps into radar measurements of range and velocity. This mapping depends on a wide variety of factors, including details of the radar motion, orientation, and the 3-D topography of the clutter.

  15. Space borne GPM dual-frequency radar simulation from high resolution ground radar observations.

    SciTech Connect

    Rose, C. R.; Chandrasekar, V.

    2004-01-01

    The Global Precipitation Measurement (GPM) mission is dedicated to improving the understanding of the global water cycle by measuring and mapping precipitation throughout the globe. The core GPM satellite will incorporate two separate precipitation radars: one operating at Ku-band (13.6 GHz) and the other at Ka band (35.6 GHz). Each radar beam will be steered such that they both point to the same location in the atmosphere. The main purpose of the dual-frequency radar system is to resolve the DSD in precipitation as well as discriminate between rain and ice. With the two beams collocated on the same precipitation volume, new algorithms are being developed to reliably es timate attenuation and rain rate. Any algorithm is based on models of precipitation. In addition, the GPM system assumes collocated beams and matched resolu tion volumes. Electromagnetic and microphysical models have been developed based on ground-based dual-frequency radar data at S-band to simulate Ku- and Ka-band results for comparison with the new GPM algorithms. This paper evaluates the dual-frequency inversion algorithm with synthesized S-band and known perfect data and presents results. Results show the expected performance of the new dual-precipitation radar algorithms with the potential for guiding algorithm and system improvements.

  16. Shuttle imaging radar-C science plan

    NASA Technical Reports Server (NTRS)

    1986-01-01

    The Shuttle Imaging Radar-C (SIR-C) mission will yield new and advanced scientific studies of the Earth. SIR-C will be the first instrument to simultaneously acquire images at L-band and C-band with HH, VV, HV, or VH polarizations, as well as images of the phase difference between HH and VV polarizations. These data will be digitally encoded and recorded using onboard high-density digital tape recorders and will later be digitally processed into images using the JPL Advanced Digital SAR Processor. SIR-C geologic studies include cold-region geomorphology, fluvial geomorphology, rock weathering and erosional processes, tectonics and geologic boundaries, geobotany, and radar stereogrammetry. Hydrology investigations cover arid, humid, wetland, snow-covered, and high-latitude regions. Additionally, SIR-C will provide the data to identify and map vegetation types, interpret landscape patterns and processes, assess the biophysical properties of plant canopies, and determine the degree of radar penetration of plant canopies. In oceanography, SIR-C will provide the information necessary to: forecast ocean directional wave spectra; better understand internal wave-current interactions; study the relationship of ocean-bottom features to surface expressions and the correlation of wind signatures to radar backscatter; and detect current-system boundaries, oceanic fronts, and mesoscale eddies. And, as the first spaceborne SAR with multi-frequency, multipolarization imaging capabilities, whole new areas of glaciology will be opened for study when SIR-C is flown in a polar orbit.

  17. Laboratory demonstration of an effective range sidelobe suppression technique for spaceborne rain radars

    NASA Astrophysics Data System (ADS)

    Im, E.; Tanner, A.; Wilson, W.; Denning, R.; Durden, S.; Li, F.

    A 13.8 GHz linear frequency-modulated pulse compression radar electronics system for spaceborne and airborne radar rain mapping applications has been built and tested. Preliminary test results indicate that the far range sidelobes can be suppressed to the desired -60 B level in the laboratory environment.

  18. Laboratory demonstration of an effective range sidelobe suppression technique for spaceborne rain radars

    NASA Technical Reports Server (NTRS)

    Im, E.; Tanner, A.; Wilson, W.; Denning, R.; Durden, S.; Li, F.

    1991-01-01

    A 13.8 GHz linear frequency-modulated pulse compression radar electronics system for spaceborne and airborne radar rain mapping applications has been built and tested. Preliminary test results indicate that the far range sidelobes can be suppressed to the desired -60 B level in the laboratory environment.

  19. Radar Image, Color as Height , Salalah, Oman

    NASA Technical Reports Server (NTRS)

    2000-01-01

    This radar image includes the city of Salalah, the second largest city in Oman. It illustrates how topography determines local climate and, in turn, where people live. This area on the southern coast of the Arabian Peninsula is characterized by a narrow coastal plain (bottom) facing southward into the Arabian Sea, backed by the steep escarpment of the Qara Mountains. The backslope of the Qara Mountains slopes gently into the vast desert of the Empty Quarter (at top). This area is subject to strong monsoonal storms from the Arabian Sea during the summer, when the mountains are enveloped in a sort of perpetual fog. The moisture from the monsoon enables agriculture on the Salalah plain, and also provides moisture for Frankincense trees growing on the desert (north) side of the mountains. In ancient times, incense derived from the sap of the Frankincense tree was the basis for an extremely lucrative trade. Radar and topographic data are used by historians and archaeologists to discover ancient trade routes and other significant ruins.

    This image combines two types of data from the Shuttle Radar Topography Mission. The image brightness corresponds to the strength of the radar signal reflected from the ground, while colors show the elevation as measured by SRTM. Colors range from green at the lowest elevations to brown at the highest elevations. This image contains about 1070 meters (3500 feet) of total relief. White speckles on the face of some of the mountains are holes in the data caused by steep terrain. These will be filled using coverage from an intersecting pass.

    The Shuttle Radar Topography Mission (SRTM), launched on February 11,2000, uses the same radar instrument that comprised the Spaceborne Imaging Radar-C/X-Band Synthetic Aperture Radar (SIR-C/X-SAR) that flew twice on the Space Shuttle Endeavour in 1994. The mission is designed to collect three-dimensional measurements of the Earth's surface. To collect the 3-D data, engineers added a 60-meter

  20. Space radar image of New York City

    NASA Technical Reports Server (NTRS)

    1995-01-01

    This radar image of the New York city metropolitan area. The island of Manhattan appears in the center of the image. The green-colored rectangle on Manhattan is Central Park. This image was acquired by the Spaceborne Imaging Radar-C/X-band Synthetic Aperture Radar (SIR-C/ X-SAR) aboard the space shuttle Endeavour on October 10, 1994. North is toward the upper right. The area shown is 75.0 kilometers by 48.8 kilometers (46.5 miles by 30.2 miles). The image is centered at 40.7 degrees north latitude and 73.8 degrees west longitude. In general, light blue areas correspond to dense urban development, green areas to moderately vegetated zones and black areas to bodies of water. The Hudson River is the black strip that runs from the left edge to the upper right corner of the image. It separates New Jersey, in the upper left of the image, from New York. The Atlantic Ocean is at the bottom of the image where two barrier islands along the southern shore of Long Island are also visible. John F. Kennedy International Airport is visible above these islands. Long Island Sound, separating Long Island from Connecticut, is the dark area right of the center of the image. Many bridges are visible in the image, including the Verrazano Narrows, George Washington and Brooklyn bridges. The radar illumination is from the left of the image; this causes some urban zones to appear red because the streets are at a perpendicular angle to the radar pulse. The colors in this image were obtained using the following radar channels: red represents the L-band (horizontally transmitted and received); green represents the L-band (horizontally transmitted, vertically received); blue represents the C-band (horizontally transmitted, vertically received). Radar images like this one could be used as a tool for city planners and resource managers to map and monitor land use patterns. The radar imaging systems can clearly detect the variety of landscapes in the area, as well as the density of urban

  1. 66. VIEW SHOWING HOLD FOR RADAR CABLES AT RADAR SITE, ...

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

    66. VIEW SHOWING HOLD FOR RADAR CABLES AT RADAR SITE, LOOKING NORTH Everett Weinreb, photographer, March 1988 - Mount Gleason Nike Missile Site, Angeles National Forest, South of Soledad Canyon, Sylmar, Los Angeles County, CA

  2. Application of Interferometric Radars to Planetary Geologic Studies

    NASA Technical Reports Server (NTRS)

    Mouginis-Mark, P. J.; Rosen, P.; Freeman, A.

    2005-01-01

    Radar interferometry is rapidly becoming one of the major applications of radar systems in Earth orbit. So far the 2000 flight of the Shuttle Radar Topographic Mission (SRTM) is the only dedicated U.S. radar to be flown for the collection of interferometric data, but enough has been learned from this mission and from the use of foreign partner radars (ERS-1/2, Radarsat, ENIVISAT and JERS-1) for the potential planetary applications of this technique to be identified. A recent workshop was organized by the Jet Propulsion Laboratory and the Southern California Earthquake Center (SCEC), and was held at Oxnard, CA, from October 20th - 22nd, 2004. At this meeting, the major interest was in terrestrial radar systems, but approx. 20 or the approx. 250 attendees also discussed potential applications of interferometric radar for the terrestrial planets. The primary foci were for the detection of planetary water, the search for active tectonism and volcanism and the improved topographic mapping. This abstract provides a summary of these planetary discussions at the Oxnard meeting.

  3. Antarctic meteor observations using the Davis MST and meteor radars

    NASA Astrophysics Data System (ADS)

    Holdsworth, David A.; Murphy, Damian J.; Reid, Iain M.; Morris, Ray J.

    2008-07-01

    This paper presents the meteor observations obtained using two radars installed at Davis (68.6°S, 78.0°E), Antarctica. The Davis MST radar was installed primarily for observation of polar mesosphere summer echoes, with additional transmit and receive antennas installed to allow all-sky interferometric meteor radar observations. The Davis meteor radar performs dedicated all-sky interferometric meteor radar observations. The annual count rate variation for both radars peaks in mid-summer and minimizes in early Spring. The height distribution shows significant annual variation, with minimum (maximum) peak heights and maximum (minimum) height widths in early Spring (mid-summer). Although the meteor radar count rate and height distribution variations are consistent with a similar frequency meteor radar operating at Andenes (69.3°N), the peak heights show a much larger variation than at Andenes, while the count rate maximum-to-minimum ratios show a much smaller variation. Investigation of the effects of the temporal sampling parameters suggests that these differences are consistent with the different temporal sampling strategies used by the Davis and Andenes meteor radars. The new radiant mapping procedure of [Jones, J., Jones, W., Meteor radiant activity mapping using single-station radar observations, Mon. Not. R. Astron. Soc., 367(3), 1050-1056, doi: 10.1111/j.1365-2966.2006.10025.x, 2006] is investigated. The technique is used to detect the Southern delta-Aquarid meteor shower, and a previously unknown weak shower. Meteoroid speeds obtained using the Fresnel transform are presented. The diurnal, annual, and height variation of meteoroid speeds are presented, with the results found to be consistent with those obtained using specular meteor radars. Meteoroid speed estimates for echoes identified as Southern delta-Aquarid and Sextantid meteor candidates show good agreement with the theoretical pre-atmospheric speeds of these showers (41 km s -1 and 32 km s -1

  4. Weather radar research at the USA's storm laboratory

    NASA Technical Reports Server (NTRS)

    Doviak, R. J.

    1982-01-01

    Radar research that is directed toward improving storm forecasts and hazard warnings and studying lightning is discussed. The two moderately sensitive Doppler weather radars in central Oklahoma, with their wide dynamic range, have demonstrated the feasibility of mapping wind fields in all weather conditions from the clear skies of quiescent air and disturbed prestorm air near the earth's surface to the optically opaque interior of severe and sometimes tornadic thunderstorms. Observations and analyses of Doppler weather radar data demonstrate that improved warning of severe storm phenomena and improved short-term forecast of storms may be available when Doppler techniques are well integrated into the national network of weather radars. When used in combination with other sensors, it provides an opportunity to learn more about the complex interrelations between the wind, water, and electricity in storms.

  5. Preliminary radar systems analysis for Venus orbiter missions

    NASA Technical Reports Server (NTRS)

    Brandenburg, R. K.; Spadoni, D. J.

    1971-01-01

    A short, preliminary analysis is presented of the problems involved in mapping the surface of Venus with radar from an orbiting spacecraft. Two types of radar, the noncoherent sidelooking and the focused synthetic aperture systems, are sized to fulfill two assumed levels of Venus exploration. The two exploration levels, regional and local, assumed for this study are based on previous Astro Sciences work (Klopp 1969). The regional level is defined as 1 to 3 kilometer spatial and 0.5 to 1 km vertical resolution of 100 percent 0 of the planet's surface. The local level is defined as 100 to 200 meter spatial and 50-10 m vertical resolution of about 100 percent of the surfAce (based on the regional survey). A 10cm operating frequency was chosen for both radar systems in order to minimize the antenna size and maximize the apparent radar cross section of the surface.

  6. A barrier radar concept

    NASA Astrophysics Data System (ADS)

    Marshall, J.; Ball, C.; Weissman, I.

    A description is given of a low power, light-weight radar that can be quickly set up and operated on batteries for extended periods of time to detect airborne intruders. With low equipment and operating costs, it becomes practical to employ a multiplicity of such radars to provide an unbroken intrusion fence over the desired perimeter. Each radar establishes a single transmitted fan beam extending vertically from horizon to horizon. The beam is generated by a two-face array antenna built in an A-frame configuration and is shaped, through phasing of the array elements, to concentrate the transmitter power in a manner consistent with the expected operating altitude ceiling of the targets of interest. The angular width of this beam in the dimension transverse to the fan depends on the radar transmission frequency and the antenna aperture dimension, but is typically wide enough so that a target at the maximum altitude or range will require tens of seconds to pass through the beam. A large number of independent samples of radar data will thus be available to provide many opportunities for target detection.

  7. 33. Perimeter acquisition radar building room #320, perimeter acquisition radar ...

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

    33. Perimeter acquisition radar building room #320, perimeter acquisition radar operations center (PAROC), contains the tactical command and control group equipment required to control the par site. Showing spacetrack monitor console - Stanley R. Mickelsen Safeguard Complex, Perimeter Acquisition Radar Building, Limited Access Area, between Limited Access Patrol Road & Service Road A, Nekoma, Cavalier County, ND

  8. Coordinated Radar Resource Management for Networked Phased Array Radars

    DTIC Science & Technology

    2014-12-01

    Research and Development Canada Ottawa, Canada K1A 0Z4 Email: Peter.Moo@drdc-rddc.gc.ca Abstract A phased array radar has the ability to rapidly and...search and Development Canada (DRDC) Ottawa to analyse the performance of radar resource management techniques for naval radars operating in a littoral

  9. Phase modulating the Urbana radar

    NASA Technical Reports Server (NTRS)

    Herrington, L. J., Jr.; Bowhill, S. A.

    1983-01-01

    The design and operation of a switched phase modulation system for the Urbana Radar System are discussed. The system is implemented and demonstrated using a simple procedure. The radar system and circuits are described and analyzed.

  10. Coherent IR radar technology

    NASA Astrophysics Data System (ADS)

    Gschwendtner, A. B.; Harney, R. C.; Hull, R. J.

    Recent progress in the development of coherent IR radar equipment is reviewed, focusing on the Firepond laser radar installation and the more compact systems derived for it. The design and capabilities of Firepond as a long-range satellite-tracking device are outlined. The technological improvements necessary to make laser radar mobile are discussed: a lightweight, stable 5-10-W transmitter laser for both CW and pulsed operation, a 12-element HgCdTe detector array, an eccentric-pupil Ritchey-Chretien telescope, and a combination of near-field phase modification and anamorphic expansion to produce a fan beam of relatively uniform intensity. Sample images obtained with a prototype system are shown, and the applicability of the mobile system to range-resolved coherent DIAL measurement is found to be similar to that of a baseline DIAL system.

  11. The MST Radar Technique

    NASA Technical Reports Server (NTRS)

    Balsley, B. B.

    1985-01-01

    The past ten year have witnessed the development of a new radar technique to examine the structure and dynamics of the atmosphere between roughly 1 to 100 km on a continuous basis. The technique is known as the MST (for Mesosphere-Stratosphere-Troposphere) technique and is usable in all weather conditions, being unaffected by precipitation or cloud cover. MST radars make use of scattering from small scale structure in the atmospheric refractive index, with scales of the order of one-half the radar wavelength. Pertinent scale sizes for middle atmospheric studies typically range between a fraction of a meter and a few meters. The structure itself arises primarily from atmospheric turbulence. The technique is briefly described along with the meteorological parameters it measures.

  12. Seasat radar geomorphic applications in coastal and wetland environments, southeastern U.S

    NASA Technical Reports Server (NTRS)

    Macdonald, H. C.

    1981-01-01

    The application of Seasat Synthetic Aperture Radar (SAR) to the assessment of terrain conditions in coastal environments is considered. Drainage patterns and plant community spatial relationships can be adequately mapped as is shown by Seasat L-band imagery of the southeastern Gulf Coast and Atlantic Coastal Plain. Anomalously bright radar signatures are identified as characteristic of mangrove and cypress swamps. Marshes have a low radar return, less than that from non-marsh areas and open water in tidal channels. Drainage patterns for coastal plain transition zones can also be determined. Spaceborne imaging radar provides information which complements geomorphic analyses presently obtained with optical sensors.

  13. Radar data smoothing filter study

    NASA Technical Reports Server (NTRS)

    White, J. V.

    1984-01-01

    The accuracy of the current Wallops Flight Facility (WFF) data smoothing techniques for a variety of radars and payloads is examined. Alternative data reduction techniques are given and recommendations are made for improving radar data processing at WFF. A data adaptive algorithm, based on Kalman filtering and smoothing techniques, is also developed for estimating payload trajectories above the atmosphere from noisy time varying radar data. This algorithm is tested and verified using radar tracking data from WFF.

  14. Systems and Methods for Radar Data Communication

    NASA Technical Reports Server (NTRS)

    Bunch, Brian (Inventor); Szeto, Roland (Inventor); Miller, Brad (Inventor)

    2013-01-01

    A radar information processing system is operable to process high bandwidth radar information received from a radar system into low bandwidth radar information that may be communicated to a low bandwidth connection coupled to an electronic flight bag (EFB). An exemplary embodiment receives radar information from a radar system, the radar information communicated from the radar system at a first bandwidth; processes the received radar information into processed radar information, the processed radar information configured for communication over a connection operable at a second bandwidth, the second bandwidth lower than the first bandwidth; and communicates the radar information from a radar system, the radar information communicated from the radar system at a first bandwidth.

  15. Development of a Drillrod/Telemetry Radar

    SciTech Connect

    Raton Technology Research, Inc.

    1999-11-12

    Efficient extraction of deeply buried natural resources is dependent upon accurate geologic models. The model becomes the basis for developing plans for extraction of the resource. Geoscientists working in geothermal and hydrocarbon recovery have a great deal in common with fellow geoscientists working in the mining industry. They appreciate the intractable problem of increasing the depth of investigation to tens of meters from the wellbore. The goal of this project was to develop a borehole radar tool to acquire data within tens of meters from the wellbore. For geothermal and hydrocarbon applications, the tool was to acquire data for mapping fractures surrounding the wellbore. In mining of coal, the radar acquires data for determining coal seam thickness and detecting geologic anomalies ahead of mining.

  16. Forest discrimination with multipolarization imaging radar

    NASA Technical Reports Server (NTRS)

    Ford, J. P.; Wickland, D. E.

    1985-01-01

    The use of radar polarization diversity for discriminating forest canopy variables on airborne synthetic-aperture radar (SAR) images is evaluated. SAR images were acquired at L-Band (24.6 cm) simultaneously in four linear polarization states (HH, HV, VH, and VV) in South Carolina on March 1, 1984. In order to relate the polarization signatures to biophysical properties, false-color composite images were compared to maps of forest stands in the timber compartment. In decreasing order, the most useful correlative forest data are stand basal area, forest age, site condition index, and forest management type. It is found that multipolarization images discriminate variation in tree density and difference in the amount of understory, but do not discriminate between evergreen and deciduous forest types.

  17. Spaceborne Imaging Radar Symposium

    NASA Technical Reports Server (NTRS)

    Elachi, C.

    1983-01-01

    An overview of the present state of the art in the different scientific and technological fields related to spaceborne imaging radars was presented. The data acquired with the SEASAT SAR (1978) and Shuttle Imaging Radar, SIR-A (1981) clearly demonstrated the important emphasis in the 80's is going to be on in-depth research investigations conducted with the more flexible and sophisticated SIR series instruments and on long term monitoring of geophysical phenomena conducted from free-flying platforms such as ERS-1 and RADARSAT.

  18. Microwave radar oceanographic investigations

    NASA Technical Reports Server (NTRS)

    Jackson, F. C.

    1988-01-01

    The Radar Ocean Wave Spectrometer (ROWS) technique was developed and demonstrated for measuring ocean wave directional spectra from air and space platforms. The measurement technique was well demonstrated with data collected in a number of flight experiments involving wave spectral comparisons with wave buoys and the Surface Contour Radar (SCR). Recent missions include the SIR-B underflight experiment (1984), FASINEX (1986), and LEWEX (1987). ROWS related activity is presently concentrating on using the aircraft instrument for wave-processes investigations and obtaining the necessary support (consensus) for a satellite instrument development program. Prospective platforms include EOS and the Canadian RADARSAT.

  19. Spaceborne laser radar.

    NASA Technical Reports Server (NTRS)

    Flom, T.

    1972-01-01

    Development of laser systems to acquire and track targets in applications such as the rendezvous and docking of two spacecraft. A scan technique is described whereby a narrow laser beam is simultaneously scanned with an equally narrow receiver field-of-view without the aid of mechanical gimbals. Equations are developed in order to examine the maximum acquisition and tracking rates, and the maximum target range for a scanning laser radar system. A recently built prototype of a small, lightweight, low-power-consuming scanning laser radar is described.

  20. Radar Investigations of Asteroids

    NASA Technical Reports Server (NTRS)

    Ostro, S. J.

    1984-01-01

    Radar investigations of asteroids, including observations during 1984 to 1985 of at least 8 potential targets and continued analyses of radar data obtained during 1980 to 1984 for 30 other asteroids is proposed. The primary scientific objectives include estimation of echo strength, polarization, spectral shape, spectral bandwidth, and Doppler shift. These measurements yield estimates of target size, shape, and spin vector; place constraints on topography, morphology, density, and composition of the planetary surface; yield refined estimates of target orbital parameters; and reveals the presence of asteroidal satellites.

  1. SEASAT Synthetic Aperture Radar Data

    NASA Technical Reports Server (NTRS)

    Henderson, F. M.

    1981-01-01

    The potential of radar imagery from space altitudes is discussed and the advantages of radar over passive sensor systems are outlined. Specific reference is made to the SEASAT synthetic aperture radar. Possible applications include oil spill monitoring, snow and ice reconnaissance, mineral exploration, and monitoring phenomena in the urban environment.

  2. Space radar image of New Orleans, Louisiana

    NASA Technical Reports Server (NTRS)

    1995-01-01

    This image of the area surrounding the city of New Orleans, Louisiana in the southeastern United States demonstrates the ability of multi-frequency imaging radar to distinguish different types of land cover. The dark area in the center is Lake Pontchartrain. The thin line running across the lake is a causeway connecting New Orleans to the city of Mandeville. Lake Borgne is the dark area in the lower right of the image. The Mississippi River appears as a dark, wavy line in the lower left. The white dots on the Mississippi are ships. The French Quarter is the brownish square near the left center of the image. Lakefront Airport, a field used mostly for general aviation, is the bright spot near the center, jutting out into Lake Pontchartrain. The image was acquired by the Spaceborne Imaging Radar C/X-Band Synthetic Aperture Radar (SIR-C/X-SAR) during orbit 39 of space shuttle Endeavour on October 2, 1994. The area is located at 30.10 degrees north latitude and 89.1 degrees west longitude. The area shown is approximately 100 kilometers (60 miles) by 50 kilometers (30 miles). The colors in this image were obtained using the following radar channels: red represents the L-band (horizontally transmitted and received); green represents the C-band (horizontally transmitted and received); blue represents the L-band (vertically transmitted and received). The green areas are primarily vegetation consisting of swamp land and swamp forest (bayou) growing on sandy soil, while the pink areas are associated with reflections from buildings in urban and suburban areas. Different tones and colors in the vegetation areas will be studied by scientists to see how effective imaging radar data is in discriminating between different types of wetlands. Accurate maps of coastal wetland areas are important to ecologists studying wild fowl and the coastal environment.

  3. Space Radar Image of Pishan, China

    NASA Technical Reports Server (NTRS)

    1994-01-01

    This radar image is centered near the small town of Pishan in northwest China, about 280 km (174 miles) southeast of the city of Kashgar along the ancient Silk Route in the Taklamakan desert of the Xinjiang Province. Geologists are using this radar image as a map to study past climate changes and tectonics of the area. The irregular lavender branching patterns in the center of the image are the remains of ancient alluvial fans, gravel deposits that have accumulated at the base of the mountains during times of wetter climate. The subtle striped pattern cutting across the ancient fans are caused by thrusting of the Kun Lun Mountains north. This motion is caused by the continuing plate-tectonic collision of India with Asia. Modern fans show up as large lavender triangles above the ancient fan deposits. Yellow areas on the modern fans are vegetated oases. The gridded pattern results from the alignment of poplar trees that have been planted as wind breaks. The reservoir at the top of the image is part of a sophisticated irrigation system that supplies water to the oases. This image was acquired by the Spaceborne Imaging Radar-C/X-band Synthetic Aperture Radar (SIR-C/X-SAR) aboard the space shuttle Endeavour in April 1994. This image is centered at 37.4 degrees north latitude, 78.3 degrees east longitude and shows an area approximately 50 km by 100 km (31 miles by 62 miles). The colors are assigned to different frequencies and polarizations of the radar as follows: Red is L-band horizontally transmitted, horizontally received; green is L-band horizontally transmitted, vertically received; and blue is C-band horizontally transmitted and vertically received. SIR-C/X-SAR, a joint mission of the German, Italian, and the United States space agencies, is part of NASA's Mission to Planet Earth.

  4. Shuttle radar topography mapper (SRTM)

    NASA Astrophysics Data System (ADS)

    Jordan, Rolando L.; Caro, Edward R.; Kim, Yunjin; Kobrick, Michael; Shen, Yuhsyen; Stuhr, Frederick V.; Werner, Marian U.

    1996-12-01

    The use of interferometric SAR (IFSAR) to measure elevation is one of the most powerful and promising capabilities of radar. A properly equipped spaceborne IFSAR system can produce a highly accurate global digital elevation map, including cloud-covered areas, in significantly less time and at significantly lower cost than with other systems. For accurate topography, the interferometric measurements must be performed simultaneously in physically sperate receive system, since measurements made at different times with the same system suffer significant decorrelation. The US/German/Italian spaceborne imaging radar C/X-band SAR (SIR-C/X-SAR), successfully flown twice in 1994 aboard the Space Shuttle Endeavor, offers a unique opportunity for global multifrequency elevation mapping by the year 2000. With appropriate augmentation, SIR-C/X-SAR is capable of producing an accurate elevation map covering 80 percent of the Earth's land surface in a single 10-day Shuttle flight. The existing US SIR-C SCANSAR mode provides a 225-km swath at C-band, which makes this coverage possible. Addition of a C-band receive antenna, extended from the Shuttle bay on a mast and operating in concert with the existing SIR-C antenna, produces an interferometric pair. Accuracy is enhanced by utilizing the SIR-C dual polarizations simultaneously to form separate SCANSAR beams. Due to the practical limitation of approximately 60 meters for the mast length, the longer SIR-C L-band wavelength does not produce useful elevation measurement accuracy. IFSAR measurements can also be obtained by the German/Italian X-SAR, simultaneously with SIR-C, by utilizing an added outboard antenna at X-band to produce a swath coverage of about 50 km. Accuracy can be enhanced at both frequencies by processing both ascending and descending data takes. It is estimated that the 90 percent linear absolute elevation error achievable is less that 16 meters for elevation postings of 30 meters. This will be the first use of

  5. Space Radar Image of Los Angeles, California

    NASA Technical Reports Server (NTRS)

    1994-01-01

    This is a radar image of Los Angeles, California, taken on October 2, 1994. Visible in the image are Long Beach Harbor at the bottom right (south corner of the image), Los Angeles International Airport at the bottom center, with Santa Monica just to the left of it and the Hollywood Hills to the left of Santa Monica. Also visible in the image are the freeway systems of Los Angeles, which appear as dark lines. The San Gabriel Mountains (center top) and the communities of San Fernando Valley, Simi Valley and Palmdale can be seen on the left-hand side. This image was acquired by the Spaceborne Imaging Radar-C and X-band Synthetic Aperture Radar (SIR-C/X-SAR) aboard the space shuttle Endeavour on its 24th orbit. The image is centered at 34 degrees north latitude, 118 degrees west longitude. The area shown is approximately 100 kilometers by 52 kilometers (62 miles by 32 miles). This single-frequency SIR-C image was obtained by the L-band (24 cm) radar channel, horizontally transmitted and received. Portions of the Pacific Ocean visible in this image appear very dark as do freeways and other flat surfaces such as the airport runways. Mountains in the image are dark grey, with brighter patches on the mountain slopes, which face in the direction of the radar illumination (from the top of the image). Suburban areas, with the low-density housing and tree-lined streets that are typical of Los Angeles, appear as lighter grey. Areas with high-rise buildings, such as downtown Los Angeles, appear in very bright white, showing a higher density of housing and streets which run parallel to the radar flight track. Scientists hope to use radar image data from SIR-C/X-SAR to map fire scars in areas prone to brush fires, such as Los Angeles. In this image, the Altadena fire area is visible in the top center of the image as a patch of mountainous terrain which is slightly darker than the nearby mountains. Using all the radar frequency and polarization images provided by SIR

  6. Radar Scattering Properties of Terra Meridiani, Mars

    NASA Astrophysics Data System (ADS)

    Larsen, K. W.; Haldemann, A. F.; Jurgens, R. F.; Slade, M. A.; Arvidson, R. E.

    2002-12-01

    A series of fourteen radar observations of Mars were made during the 2001 opposition. Four of these observation tracks passed over Terra Meridiani, a prime candidate landing site for one of the 2003 Mars Exploration Rover missions. Observations were conducted using X-band (3.5 centimeter wavelength) radar transmitted with a pseudo-random binary phase encoding which, combined with the frequency resolution of the processing FFT, yields a maximum spatial resolution of approximately five kilometers. Actual spatial resolution is coarser than this (between five and twenty kilometers) due to signal-to-noise considerations that predicated longer integration times as well as greater planetary ranges for the off-opposition observations. We have processed the Terra Meridiani data in stages, beginning with one-dimensional sub-radar track profiles and culminating with four-station interferometry. Not all observations were amendable to the full four-station interferometry, due to technical issues, but were processed with a minimum of two stations to remove the spatial ambiguities inherent to radar observations. Our processing yields one- and two-dimensional maps of the surface reflectivity along the radar track. We extract scattering data for points along the sub-radar track, where the angle in incidence varies most, and model the scattering function. The multi-station reflectivity data is also modeled according to the Hagfors scattering model to extract two-dimensional maps of RMS roughness and dielectric constant. The RMS roughness data for the Terra Meridiani landing sites shows the local surface slopes to be less than 3 degrees, on the scale of tens of wavelengths. An enhanced dielectric constant is apparent over Terra Meridiani that is spatially correlated with the MGS detected hematite deposits. The level of the enhancement is consistent with the inclusion of 10-15 percent hematite, according to a weighted dielectric or PVL model. Integral to our processing, and new to

  7. Mapping of volcanic eruption based on InSAR

    NASA Astrophysics Data System (ADS)

    Mikhailukova, Polina; Sazonov, Alexey; Tutubalina, Olga

    2016-04-01

    Radar interferometry often used only as the method for calculation of heights or vertical displacements. Meanwhile it's a multistage processing which allows to use results of these stages for thematic analysis. Author has explored and described two-pass differential radar interferometry as an independent method of mapping of changes in lava flow topography. The study region is Tolbachinsky Dol (Kamchatka), where a fissure eruption occurred in 2012-2013. Remote sensing data (optical and radar imagery) were regularly acquired during the whole eruption period. Radar imagery was acquired by Radarsat-2 in June - October 2013 from both descending and ascending orbits. These series of radar interferometric pairs, optical imagery, digital elevation model (DEM) and results of fieldwork provide valuable information for complex thematic mapping. A series of thematic maps was created as a result of the study. They show dynamics of lava flow areas, and also provide complex maps of lava flow formation. These maps demonstrate the possibility of radar interferometry for thematic mapping topography changes in volcanic regions. Author analyzed the method accuracy using two series of radar imagery (from ascending and descending orbits). The comparison showed good agreement between maps based on the processing of radar data from different orbits.

  8. First Results From the GeoSAR Mapping Instrument

    NASA Technical Reports Server (NTRS)

    Hensley, Scott; Wheeler, Kevin; Berkun, Andy; Brown, Walt; Chapin, Elaine; Freedman, Adam; Hamilton, Gary; Kroger, Peter; Michel, Charles Le. Thierry; Moller, Delwyn

    1999-01-01

    Geosynchronous Synthetic Aperture Radar (GeoSAR) is a consortium project consisting of The Jet Propulsion Laboratory (JPL), Calgis (a small GIS company based in Fresno, CA) and the California Department of Conservation with funding provided by Defense Research Projects Agency (DARPA) started in November 1996. The two main objectives of the GeoSAR Program are: 1) To develop a state of the art dual frequency interferometric radar mapping instrument capable of mapping the true ground surface height beneath the vegetation canopy; and 2) To transition this mapping technology to a commercial company, Calgis. JPL, the technical lead, has the following program deliverables at program completion in November 1999 include radar design and radar hardware for X-band (3 cm) and P-band (83 cm) radars, processor software, hardware and documentation, and calibrated X-band radar.

  9. Radar Exploration of Cometary Nuclei

    NASA Astrophysics Data System (ADS)

    Gim, Yonggyu; Heggy, E.; Belton, M.; Weissman, P.; Asphaug, E.

    2012-10-01

    We have developed a mission formulation, based on the use of previously flown planetary radar sounding techniques, to image the 3D internal structure of the nucleus of a Jupiter-family comet (JFC). Believed to originate in the outer solar system and to be delivered recently to the inner solar system from the Kuiper Belt, JFCs are among the most primitive bodies accessible by spacecraft, and are indicated in the 2010 Decadal Survey as primary targets for primitive bodies sample return. We consider a sounder design operating at dual frequencies, 5 and 15 MHz center frequencies with 1 and 10 MHz bandwidths, respectively. Operating from close orbit about the nucleus of a spinning comet nucleus, CORE obtains a dense network of echoes that are used to image its interior structure to 10 m and to map the dielectric properties inside the nucleus to better than 200 m throughout. Clear images of internal structure and dielectric composition will reveal how the nucleus was formed and how it has evolved. Radiometric tracking of the spacecraft orbit will provide an interior mass distribution that constrains the radar-based models of interior composition. High-resolution visible and infrared color images provide surface and exterior boundary conditions for interior models and hypotheses. They present the geology and morphology of the nucleus surface at meter-scales, and the time-evolving activity, structure, and composition of the inner coma. By making global yet detailed connections from interior to exterior, the data from CORE will provide answers to fundamental questions about the earliest stages of planetesimal evolution and planet formation, will be an important complement to the Rosetta mission science, and will lay the foundation for comet nucleus sample return.

  10. Principles and applications of imaging radar. Manual of remote sensing: Third edition, Volume 2

    SciTech Connect

    Henderson, F.M.; Lewis, A.J.

    1998-12-31

    This second volume in the Third Edition of the Manual of Remote Sensing offers a current and comprehensive survey of the theory, methods, and applications of imaging radar for geoscientists, engineers and application scientists interested in the advantages of radar remote sensing. Produced under the auspices of the American Society for Photogrammetry and Remote Sensing, it brings together contributions from experts around the world to discuss the basic principles of imaging radars and trace the research activity--past, present, and future--across the many sciences where radar remote sensing may be applied. This book offers an invaluable snapshot of radar remote sensing technology, including radargrammetry, radar polarimetry and interferometry and its uses. It combines technical and procedural coverage of systems, data interpretation, and other fundamentals with generous coverage of practical applications in agriculture; forestry; soil moisture monitoring; geology; geomorphology and hydrology; oceanography; land use, land cover mapping and archeology.

  11. Conventional and synthetic aperture processing for airborne ground-penetrating radar

    NASA Astrophysics Data System (ADS)

    Cameron, Robert M.; Simkins, William L.; Brown, Russell D.

    1994-07-01

    For the past four years Airborne Environmental Surveys, a division of Era Aviation, Inc., has used unique and patented airborne frequency modulated, continuous wave radars and processes for detection and mapping subsurface phenomena. Primary application has focused on the detection of manmade objects in landfills, hazardous waste sites (some of which contain unexploded ordnance), and subsurface plumes of refined free- floating hydrocarbons. Recently, MSB Technologies, Inc. has developed a form of synthetic aperture radar processing, called GPSAR, that is tailored especially for the AES radars. Used as an adjunct to more conventional airborne ground-penetrating radar data processing techniques, GPSAR takes advantage of the radars' coherent transmission and produces imagery that is better focused and more accurate in determining an object's range and true depth. This paper describes the iterative stages of data processing and analysis used with the radars and shows the added advantages that GPSAR processing offers.

  12. GEOS-3 radar altimeter study for the South Atlantic Bight

    NASA Technical Reports Server (NTRS)

    Leitao, C. D.; Huang, N.; Parsons, C. L.; Parra, C. G.; Mcmill, J. D.; Hayes, G. S.

    1980-01-01

    Three years of radar altimeter data from GEOS-3 for the South Atlantic Bight were processed. Mean monthly topographic maps were produced which estimate geostrophic flow in the region. Statistical distribution of the surface wind speed and significant wave height as a function of both space and time are presented.

  13. Interception of LPI Radar Signals

    DTIC Science & Technology

    1991-11-01

    AD-A246 315!I! I!! II I’ IIi INTERCEPTION OF LPI RADAR SIGNALS (U) by Jim P.Y. Lee DEFENCE RESEARCH ESTABLISHMENT OTTAWA TECHNICAL NOTE 91-23 Canadd...November 1991Ottawa 92-041269’ 2 2 18 II.2t1111111I 111111! !_ 1+1 efrc nadonds INTERCEPTION OF LPI RADAR SIGNALS (U) by Jim P.Y. Lee Radar E"Sect&ion... radar may employ against current EW receivers. The general conclusion is that it is possible to design a LPI radar which is effective against current

  14. Synthetic Aperture Radar Interferometry

    NASA Technical Reports Server (NTRS)

    Rosen, P. A.; Hensley, S.; Joughin, I. R.; Li, F.; Madsen, S. N.; Rodriguez, E.; Goldstein, R. M.

    1998-01-01

    Synthetic aperture radar interferometry is an imaging technique for measuring the topography of a surface, its changes over time, and other changes in the detailed characteristics of the surface. This paper reviews the techniques of interferometry, systems and limitations, and applications in a rapidly growing area of science and engineering.

  15. Netted LPI RADARs

    DTIC Science & Technology

    2011-09-01

    Characteristics ALQ-172 B-52G/H Self- protection Track/search radar jamming, steerable jam beams , software programmable, phased array antenna ...bore sight: knowing the pattern of the antenna’s gain, two or more intercepts within the antenna main beam are sufficient to determine the...14 a. Low Level Antenna Sidelobes .............14 b. Antenna Scan Patterns ...................18 4. Carrier Frequency Selection

  16. Rain radar instrument definition

    NASA Astrophysics Data System (ADS)

    Vincent, Nicolas; Chenebault, J.; Suinot, Noel; Mancini, Paolo L.

    1996-12-01

    As a result of a pre-phase a study, founded by ESA, this paper presents the definition of a spaceborne Rain Radar, candidate instrument for earth explorer precipitation mission. Based upon the description of user requirements for such a dedicated mission, a mission analysis defines the most suitable space segment. At system level, a parametric analysis compares pros and cons of instrument concepts associated with rain rate retrieval algorithms in order to select the most performing one. Several trade-off analysis at subsystem level leads then to the definition of the proposed design. In particular, as pulse compression is implemented in order to increase the radar sensitivity, the selected method to achieve a pulse response with a side-lobe level below--60 dB is presented. Antenna is another critical rain radar subsystem and several designs are com pared: direct radiating array, single or dual reflector illuminated by single or dual feed arrays. At least, feasibility of centralized amplification using TWTA is compared with criticality of Tx/Rx modules for distributed amplification. Mass and power budgets of the designed instrument are summarized as well as standard deviations and bias of simulated rain rate retrieval profiles. The feasibility of a compliant rain radar instrument is therefore demonstrated.

  17. Frequency Diverse Array Radar

    DTIC Science & Technology

    2010-09-01

    the methods for electronic scanning of antenna systems. Techniques that have been studied in this connection include frequency variation, phase shift...an array antenna instantaneously into a desired direction where no mechanical mechanism is involved in the scanning process. Electronic scanning... methods including phase scanning, time delay scanning, and frequency scanning have been used in various radar applications; however new and cheaper

  18. Passive MIMO Radar Detection

    DTIC Science & Technology

    2013-09-01

    Hypothesis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41 3.3.3 Dependence on SNR...71 4.3.3 Dependence on SNR and DNR . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 74 4.4 Interpretations...described as a passive radar network. The topology of such networks is described as bistatic, multistatic, or multiple-input multiple-output, depending on

  19. Passive bistatic radar analysis

    NASA Astrophysics Data System (ADS)

    O'Hagan, Daniel W.; Kuschel, H.; Schiller, Joachim

    2009-06-01

    Passive Bistatic Radar (PBR) research is at its zenith with several notable PBR systems currently operational, or available for deployment. Such PBRs include the Manastash Ridge Radar (MRR) developed for and by academia; Silent Sentry developed as a commercial concern by Lockheed Martin; and Homeland Alerter (HA100) also a commercial system developed by Thales. However at present, despite the existence of numerous PBR prototypes, take up of commercial passive radar technology remains slow. This is due in part to technology immaturity, in part to politics, and particularly due to the fact that monostatic radars perform so well. If PBRs are to enjoy longevity as a viable technology then it is imperative that they address certain niche application areas, with the aforementioned MRR being one prime example of this. The focus of this paper will be an analysis of a PBR system that utilised FM radio signals of opportunity to detect aircraft targets with an RCS generally not lower than 20 m2. The paper will demonstrate the theoretical detection coverage of an FM based PBR operating in a severe interference environment.

  20. Impulse radar studfinder

    DOEpatents

    McEwan, T.E.

    1995-10-10

    An impulse radar studfinder propagates electromagnetic pulses and detects reflected pulses from a fixed range. Unmodulated pulses, about 200 ps wide, are emitted. A large number of reflected pulses are sampled and averaged. Background reflections are subtracted. Reflections from wall studs or other hidden objects are detected and displayed using light emitting diodes. 9 figs.

  1. Impulse radar studfinder

    DOEpatents

    McEwan, Thomas E.

    1995-01-01

    An impulse radar studfinder propagates electromagnetic pulses and detects reflected pulses from a fixed range. Unmodulated pulses, about 200 ps wide, are emitted. A large number of reflected pulses are sampled and averaged. Background reflections are subtracted. Reflections from wall studs or other hidden objects are detected and displayed using light emitting diodes.

  2. Space Radar Image of Bahia

    NASA Technical Reports Server (NTRS)

    1994-01-01

    limited by the nearly continuous cloud cover in the region and heavy rainfall, which occurs more than 150 days each year. The ability of the shuttle radars to 'see' through the forest canopy to the cultivated cacao below -- independent of weather or sunlight conditions --will allow researchers to distinguish forest from cabruca in unprecedented detail. This SIR-C/X-SAR image was produced by assigning red to the L-band, green to the C-band and blue to the X-band. The Una Reserve is located in the middle of the image west of the coastline and slightly northwest of Comandatuba River. The reserve's primary forests are easily detected by the pink areas in the image. The intensity of red in these areas is due to the high density of forest vegetation (biomass) detected by the radar's L-band (horizontally transmitted and vertically received) channel. Secondary forest is visible along the reserve's eastern border. The Serrado Mar mountain range is located in the top left portion of the image. Cabruca forest to the west of Una Reserve has a different texture and a yellow color. The removal of understory in cabruca forest reduces its biomass relative to primary forest, which changes the L-band and C-band penetration depth and returns, and produces a different texture and color in the image. The region along the Atlantic is mainly mangrove swamp, agricultural fields and urban areas. The high intensity of blue in this region is a result of increasing X-band return in areas covered with swamp and low vegetation. The image clearly separates the mangrove region (east of coastal Highway 001, shown in blue) from the taller and dryer forest west of the highway. The high resolution capability of SIR-C/X-SAR imaging and the sensitivity of its frequency and polarization channels to various land covers will be used for monitoring and mapping areas of importance for conservation. Spaceborne Imaging Radar-C/X-band Synthetic Aperture Radar(SIR-C/X-SAR) is part of NASA's Mission to Planet Earth

  3. Space Radar Image of Bahia

    NASA Technical Reports Server (NTRS)

    1994-01-01

    limited by the nearly continuous cloud cover in the region and heavy rainfall, which occurs more than 150 days each year. The ability of the shuttle radars to 'see' through the forest canopy to the cultivated cacao below -- independent of weather or sunlight conditions --will allow researchers to distinguish forest from cabruca in unprecedented detail. This SIR-C/X-SAR image was produced by assigning red to the L-band, green to the C-band and blue to the X-band. The Una Reserve is located in the middle of the image west of the coastline and slightly northwest of Comandatuba River. The reserve's primary forests are easily detected by the pink areas in the image. The intensity of red in these areas is due to the high density of forest vegetation (biomass) detected by the radar's L-band (horizontally transmitted and vertically received) channel. Secondary forest is visible along the reserve's eastern border. The Serrado Mar mountain range is located in the top left portion of the image. Cabruca forest to the west of Una Reserve has a different texture and a yellow color. The removal of understory in cabruca forest reduces its biomass relative to primary forest, which changes the L-band and C-band penetration depth and returns, and produces a different texture and color in the image. The region along the Atlantic is mainly mangrove swamp, agricultural fields and urban areas. The high intensity of blue in this region is a result of increasing X-band return in areas covered with swamp and low vegetation. The image clearly separates the mangrove region (east of coastal Highway 001, shown in blue) from the taller and dryer forest west of the highway. The high resolution capability of SIR-C/X-SAR imaging and the sensitivity of its frequency and polarization channels to various land covers will be used for monitoring and mapping areas of importance for conservation. Spaceborne Imaging Radar-C/X-band Synthetic Aperture Radar(SIR-C/X-SAR) is part of NASA's Mission to Planet Earth

  4. Space Radar Image of Kilauea Volcano, Hawaii

    NASA Technical Reports Server (NTRS)

    1994-01-01

    This is a deformation map of the south flank of Kilauea volcano on the big island of Hawaii, centered at 19.5 degrees north latitude and 155.25 degrees west longitude. The map was created by combining interferometric radar data -- that is data acquired on different passes of the space shuttle which are then overlayed to obtain elevation information -- acquired by the Spaceborne Imaging Radar-C/X-band Synthetic Aperture Radar during its first flight in April 1994 and its second flight in October 1994. The area shown is approximately 40 kilometers by 80 kilometers (25 miles by 50 miles). North is toward the upper left of the image. The colors indicate the displacement of the surface in the direction that the radar instrument was pointed (toward the right of the image) in the six months between images. The analysis of ground movement is preliminary, but appears consistent with the motions detected by the Global Positioning System ground receivers that have been used over the past five years. The south flank of the Kilauea volcano is among the most rapidly deforming terrains on Earth. Several regions show motions over the six-month time period. Most obvious is at the base of Hilina Pali, where 10 centimeters (4 inches) or more of crustal deformation can be seen in a concentrated area near the coastline. On a more localized scale, the currently active Pu'u O'o summit also shows about 10 centimeters (4 inches) of change near the vent area. Finally, there are indications of additional movement along the upper southwest rift zone, just below the Kilauea caldera in the image. Deformation of the south flank is believed to be the result of movements along faults deep beneath the surface of the volcano, as well as injections of magma, or molten rock, into the volcano's 'plumbing' system. Detection of ground motions from space has proven to be a unique capability of imaging radar technology. Scientists hope to use deformation data acquired by SIR-C/X-SAR and future imaging

  5. Monsoon flood boundary delineation and damage assessment using space borne imaging radar and Landsat data

    NASA Technical Reports Server (NTRS)

    Imhoff, Marc L.; Vermillion, C.; Story, M. H.; Choudhury, A. M.; Gafoor, A.

    1987-01-01

    Space-borne synthetic aperture radar (SAR) data acquired by the Shuttle Imaging Radar-B (SIR-B) Program and Landsat Multispectral Scanner Subsystem (MSS) Data from Landsat 4 were used to map flood boundaries for the assessment of flood damage in the Peoples Republic of Bangladesh. The cloud penetrating capabilities of the L-band radar provided a clear picture of the hydrologic conditions of the surface during a period of inclement weather at the end of the wet phase of the 1984 monsoon. The radar image data were digitally processed to geometrically rectify the pixel geometry and were filtered to subdue radar image speckle effects. Contrast enhancement techniques and density slicing were used to create discrete land-cover categories corresponding to surface conditions present at the time of the Shuttle overflight. The radar image classification map was digitally registered to a spectral signature classification map of the area derived from Landsat MSS data collected two weeks prior to the SIR-B mission. Classification accuracy comparisons were made between the radar and MSS classification maps, and flood boundary and flood damage assessment measurements were made with the merged data by adding the classifications and inventorying the land-cover classes inundated at the time of flooding.

  6. Close-range radar rainfall estimation and error analysis

    NASA Astrophysics Data System (ADS)

    van de Beek, C. Z.; Leijnse, H.; Hazenberg, P.; Uijlenhoet, R.

    2016-08-01

    Quantitative precipitation estimation (QPE) using ground-based weather radar is affected by many sources of error. The most important of these are (1) radar calibration, (2) ground clutter, (3) wet-radome attenuation, (4) rain-induced attenuation, (5) vertical variability in rain drop size distribution (DSD), (6) non-uniform beam filling and (7) variations in DSD. This study presents an attempt to separate and quantify these sources of error in flat terrain very close to the radar (1-2 km), where (4), (5) and (6) only play a minor role. Other important errors exist, like beam blockage, WLAN interferences and hail contamination and are briefly mentioned, but not considered in the analysis. A 3-day rainfall event (25-27 August 2010) that produced more than 50 mm of precipitation in De Bilt, the Netherlands, is analyzed using radar, rain gauge and disdrometer data. Without any correction, it is found that the radar severely underestimates the total rain amount (by more than 50 %). The calibration of the radar receiver is operationally monitored by analyzing the received power from the sun. This turns out to cause a 1 dB underestimation. The operational clutter filter applied by KNMI is found to incorrectly identify precipitation as clutter, especially at near-zero Doppler velocities. An alternative simple clutter removal scheme using a clear sky clutter map improves the rainfall estimation slightly. To investigate the effect of wet-radome attenuation, stable returns from buildings close to the radar are analyzed. It is shown that this may have caused an underestimation of up to 4 dB. Finally, a disdrometer is used to derive event and intra-event specific Z-R relations due to variations in the observed DSDs. Such variations may result in errors when applying the operational Marshall-Palmer Z-R relation. Correcting for all of these effects has a large positive impact on the radar-derived precipitation estimates and yields a good match between radar QPE and gauge

  7. Ground-penetrating radar: use and misuse

    NASA Astrophysics Data System (ADS)

    Olhoeft, Gary R.

    1999-10-01

    Ground penetrating radar (GPR) has been used to explore the subsurface of the earth since 1929. Over the past 70 years, it has been widely used, misused and abused. Use includes agriculture, archaeology, environmental and geotechnical site characterization, minerals, groundwater and permafrost exploration, tunnel, utility, and unexploded ordnance location, dam inspection, and much more. Misuse includes mistaking above ground reflections for subsurface events or mapping things from off to the side as if they were directly below, synthetic aperture processing of dispersive data, minimum phase deconvolution, locating objects smaller than resolution limits of the wavelength in the ground, ignoring Fresnel zone limitations in mapping subsurface structure, processing radar data through seismic software packages without allowing for the differences, mapping the bottom of metal pipes from the top, claiming to see through thousands of feet of sediments, and more. GPR is also being abused as the regulatory environment changes and the radiofrequency spectrum is becoming more crowded by cellular phones, pagers, garage door openers, wireless computer networks, and the like. It is often thought to be a source of interference (though it never is) and it is increasingly interfered with by other radiofrequency transmitters.

  8. Radar image San Francisco Bay Area, California

    NASA Technical Reports Server (NTRS)

    2000-01-01

    preliminary nature of this image product. These artifacts will be removed after further data processing.

    This image was acquired by the Shuttle Radar Topography Mission (SRTM) aboard the Space Shuttle Endeavour, launched on February 11,2000. SRTM uses the same radar instrument that comprised the Spaceborne Imaging Radar-C/X-Band Synthetic Aperture Radar (SIR-C/X-SAR) that flew twice on the Space Shuttle Endeavour in 1994. The mission is designed to collect three-dimensional measurements of the Earth's surface. To collect the 3-D data, engineers added a 60-meter-long (200-foot) mast, installed additional C-band and X-band antennas, and improved tracking and navigation devices. The mission is a cooperative project between the National Aeronautics and Space Administration (NASA), the National Imagery and Mapping Agency (NIMA) of the U.S. Department of Defense (DoD), and the German and Italian Space agencies. It is managed by NASA's Jet Propulsion Laboratory, Pasadena, CA, for NASA's Earth Science Enterprise, Washington, DC.

    Size: 38 km (24 miles) by 71 km (44 miles) Location: 37.7 deg. North lat., 122.2 deg. West lon. Orientation: North to the upper right Original Data Resolution: 30 meters (99 feet) Date Acquired: February 16, 2000

  9. Interdisciplinary Earth Science Applications Using Satellite Radar Altimetry

    NASA Astrophysics Data System (ADS)

    Kuo, C.; Shum, C.; Lee, H.; Dai, C.; Yi, Y.

    2012-12-01

    Satellite altimetry was conceived as a space geodetic concept for ocean surface topography mapping in the NASA-sponsored 1969 Williamstown, MA Conference, and was tested as part of the passive and active radar payload (S192), along with a radiometer and a scatterometer, on Skylab-1 in May 14, 1973. Since then, numerous radar and laser satellite altimetry missions orbiting/flying-by the Earth, Mars, Mercury, Titan and the Moon have been launched, evolving from the original scientific objective of marine gravity field mapping to a geodetic tool to address interdisciplinary Earth and planetary sciences. The accuracy of the radar altimeter has improved from 0.9 m RMS for the S-192 Skylab Ku-band compressed-pulse altimeter, to 2 cm RMS (2 second average) for the dual-frequency pulse-limited radar altimetry and associated sensors onboard TOPEX/POSEIDON. Satellite altimetry has evolved into a unique cross-disciplinary geodetic tool in addressing contemporary Earth science problems including sea-level rise, large-scale general ocean circulation, ice-sheet mass balance, terrestrial hydrology, and bathymetry. Here we provide a concise review and describe specific results on the additional recent innovative and unconventional applications of interdisciplinary science research using satellite radar altimetry, including geodynamics, land subsidence, snow depth, wetland and cold region hydrology.

  10. Evaluation of SIR-A space radar for geologic interpretation: United States, Panama, Colombia, and New Guinea

    NASA Technical Reports Server (NTRS)

    Macdonald, H.; Waite, W. P.; Kaupp, V. H.; Bridges, L. C.; Storm, M.

    1983-01-01

    Comparisons between LANDSAT MSS imagery, and aircraft and space radar imagery from different geologic environments in the United States, Panama, Colombia, and New Guinea demonstrate the interdependence of radar system geometry and terrain configuration for optimum retrieval of geologic information. Illustrations suggest that in the case of space radars (SIR-A in particular), the ability to acquire multiple look-angle/look-direction radar images of a given area is more valuable for landform mapping than further improvements in spatial resolution. Radar look-angle is concluded to be one of the most important system parameters of a space radar designed to be used for geologic reconnaissance mapping. The optimum set of system parameters must be determined for imaging different classes of landform features and tailoring the look-angle to local topography.

  11. Coherent Doppler Laser Radar: Technology Development and Applications

    NASA Technical Reports Server (NTRS)

    Kavaya, Michael J.; Arnold, James E. (Technical Monitor)

    2000-01-01

    NASA's Marshall Space Flight Center has been investigating, developing, and applying coherent Doppler laser radar technology for over 30 years. These efforts have included the first wind measurement in 1967, the first airborne flights in 1972, the first airborne wind field mapping in 1981, and the first measurement of hurricane eyewall winds in 1998. A parallel effort at MSFC since 1982 has been the study, modeling and technology development for a space-based global wind measurement system. These endeavors to date have resulted in compact, robust, eyesafe lidars at 2 micron wavelength based on solid-state laser technology; in a factor of 6 volume reduction in near diffraction limited, space-qualifiable telescopes; in sophisticated airborne scanners with full platform motion subtraction; in local oscillator lasers capable of rapid tuning of 25 GHz for removal of relative laser radar to target velocities over a 25 km/s range; in performance prediction theory and simulations that have been validated experimentally; and in extensive field campaign experience. We have also begun efforts to dramatically improve the fundamental photon efficiency of the laser radar, to demonstrate advanced lower mass laser radar telescopes and scanners; to develop laser and laser radar system alignment maintenance technologies; and to greatly improve the electrical efficiency, cooling technique, and robustness of the pulsed laser. This coherent Doppler laser radar technology is suitable for high resolution, high accuracy wind mapping; for aerosol and cloud measurement; for Differential Absorption Lidar (DIAL) measurements of atmospheric and trace gases; for hard target range and velocity measurement; and for hard target vibration spectra measurement. It is also suitable for a number of aircraft operations applications such as clear air turbulence (CAT) detection; dangerous wind shear (microburst) detection; airspeed, angle of attack, and sideslip measurement; and fuel savings through

  12. Performance Evaluation of a Radar by Computer

    DTIC Science & Technology

    1992-09-01

    spatial-resolution map (0.25 nmi x 2.80 ) is employed to select the appropriate threshold values for the ground clutter; a doppler weighting that...seconds with approximately 16 mi’ x 3-Doppler-bin resolution. The second filter integrates over 5 seconds and covers within 20 miles of radar and within 3...also includes receiver matching loss , beamshape loss , and the signal processing loss. D, can be written as D,=D, (n) MLL,= -f- (3.2) where x

  13. Synthetic aperture radar for disaster monitoring

    NASA Astrophysics Data System (ADS)

    Dunkel, R.; Saddler, R.; Doerry, A. W.

    2011-06-01

    Synthetic Aperture Radar (SAR) is well known to afford imaging in darkness and through clouds, smoke, and other obscurants. As such, it is particularly useful for mapping and monitoring a variety of natural and man-made disasters. A portfolio of SAR image examples has been collected using General Atomics Aeronautical Systems, Inc.'s (GA-ASI's) Lynx® family of Ku-Band SAR systems, flown on both operational and test-bed aircraft. Images are provided that include scenes of flooding, ice jams in North Dakota, agricultural field fires in southern California, and ocean oil slicks from seeps off the coast of southern California.

  14. An orbital radar mapper of Venus in the 1980's - Mission design and analysis

    NASA Technical Reports Server (NTRS)

    Asnin, S. K.

    1973-01-01

    A reasonable approach to the examination of Venus topography, obscured for photographic imaging, is available in the application of airborne radar mapping systems to an orbiter mission about the planet. Extrapolating the improving capabilities of earth-based radar study of Venus into the 1980's suggests that only a non-uniform, poorly resolved surface profile will be possible relative to the potential for 100% coverage at 100 meter resolution with an orbital radar. The intent of this paper is to define mission opportunities favorable for a Venus orbital mapper during the 1980's, to examine orbit design problem associated with mapping radar systems, to establish what flexibility exists for an adaptive mapping strategy, to contribute to the sizing of particular spacecraft systems, to suggest a reference mission design and demonstrate mission feasibility.

  15. An MSK Radar Waveform

    NASA Technical Reports Server (NTRS)

    Quirk, Kevin J.; Srinivasan, Meera

    2012-01-01

    The minimum-shift-keying (MSK) radar waveform is formed by periodically extending a waveform that separately modulates the in-phase and quadrature- phase components of the carrier with offset pulse-shaped pseudo noise (PN) sequences. To generate this waveform, a pair of periodic PN sequences is each passed through a pulse-shaping filter with a half sinusoid impulse response. These shaped PN waveforms are then offset by half a chip time and are separately modulated on the in-phase and quadrature phase components of an RF carrier. This new radar waveform allows an increase in radar resolution without the need for additional spectrum. In addition, it provides self-interference suppression and configurable peak sidelobes. Compared strictly on the basis of the expressions for delay resolution, main-lobe bandwidth, effective Doppler bandwidth, and peak ambiguity sidelobe, it appears that bi-phase coded (BPC) outperforms the new MSK waveform. However, a radar waveform must meet certain constraints imposed by the transmission and reception of the modulation, as well as criteria dictated by the observation. In particular, the phase discontinuity of the BPC waveform presents a significant impediment to the achievement of finer resolutions in radar measurements a limitation that is overcome by using the continuous phase MSK waveform. The phase continuity, and the lower fractional out-of-band power of MSK, increases the allowable bandwidth compared with BPC, resulting in a factor of two increase in the range resolution of the radar. The MSK waveform also has been demonstrated to have an ambiguity sidelobe structure very similar to BPC, where the sidelobe levels can be decreased by increasing the length of the m-sequence used in its generation. This ability to set the peak sidelobe level is advantageous as it allows the system to be configured to a variety of targets, including those with a larger dynamic range. Other conventionally used waveforms that possess an even greater

  16. Radar Target Recognition Using Bispectrum Correlation

    DTIC Science & Technology

    2007-06-01

    21 2. Inverse Synthetic Aperture Radar ...................................................22 3. Range Profiles...characteristics need to be stored. 2. Inverse Synthetic Aperture Radar We often identify things based on pictures and Synthetic Aperture Radar (SAR) is an...By taking multiple discrete measurements while translating the radar , a larger effective aperture can be created. Inverse Synthetic Aperture Radar

  17. 51. View of upper radar scanner switch in radar scanner ...

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

    51. View of upper radar scanner switch in radar scanner building 105 from upper catwalk level showing emanating waveguides from upper switch (upper one-fourth of photograph) and emanating waveguides from lower radar scanner switch in vertical runs. - Clear Air Force Station, Ballistic Missile Early Warning System Site II, One mile west of mile marker 293.5 on Parks Highway, 5 miles southwest of Anderson, Anderson, Denali Borough, AK

  18. Radar cross-sectional study using noise radar

    NASA Astrophysics Data System (ADS)

    Freundorfer, A. P.; Siddiqui, J. Y.; Antar, Y. M. M.

    2015-05-01

    A noise radar system is proposed with capabilities to measure and acquire the radar cross-section (RCS) of targets. The proposed system can cover a noise bandwidth of near DC to 50 GHz. The noise radar RCS measurements were conducted for selective targets like spheres and carpenter squares with and without dielectric bodies for a noise band of 400MHz-5000MHz. The bandwidth of operation was limited by the multiplier and the antennae used.

  19. 41. Perimeter acquisition radar building radar element and coaxial display, ...

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

    41. Perimeter acquisition radar building radar element and coaxial display, with drawing of typical antenna section. Drawing, from left to right, shows element, aluminum ground plane, cable connectors and hardware, cable, and back-up ring. Grey area is the concrete wall - Stanley R. Mickelsen Safeguard Complex, Perimeter Acquisition Radar Building, Limited Access Area, between Limited Access Patrol Road & Service Road A, Nekoma, Cavalier County, ND

  20. RADAR Reveals Titan Topography

    NASA Technical Reports Server (NTRS)

    Kirk, R. L.; Callahan, P.; Seu, R.; Lorenz, R. D.; Paganelli, F.; Lopes, R.; Elachi, C.

    2005-01-01

    The Cassini Titan RADAR Mapper is a K(sub u)-band (13.78 GHz, lambda = 2.17 cm) linear polarized RADAR instrument capable of operating in synthetic aperture (SAR), scatterometer, altimeter and radiometer modes. During the first targeted flyby of Titan on 26 October, 2004 (referred to as Ta) observations were made in all modes. Evidence for topographic relief based on the Ta altimetry and SAR data are presented here. Additional SAR and altimetry observations are planned for the T3 encounter on 15 February, 2005, but have not been carried out at this writing. Results from the T3 encounter relevant to topography will be included in our presentation. Data obtained in the Ta encounter include a SAR image swath

  1. Floor-plan radar

    NASA Astrophysics Data System (ADS)

    Falconer, David G.; Ueberschaer, Ronald M.

    2000-07-01

    Urban-warfare specialists, law-enforcement officers, counter-drug agents, and counter-terrorism experts encounter operational situations where they must assault a target building and capture or rescue its occupants. To minimize potential casualties, the assault team needs a picture of the building's interior and a copy of its floor plan. With this need in mind, we constructed a scale model of a single- story house and imaged its interior using synthetic-aperture techniques. The interior and exterior walls nearest the radar set were imaged with good fidelity, but the distal ones appear poorly defined and surrounded by ghosts and artifacts. The latter defects are traceable to beam attenuation, wavefront distortion, multiple scattering, traveling waves, resonance phenomena, and other effects not accounted for in the traditional (noninteracting, isotropic point scatterer) model for radar imaging.

  2. Space radar image of Mauna Loa, Hawaii

    NASA Technical Reports Server (NTRS)

    1995-01-01

    This image of the Mauna Loa volcano on the Big Island of Hawaii shows the capability of imaging radar to map lava flows and other volcanic structures. Mauna Loa has erupted more than 35 times since the island was first visited by westerners in the early 1800s. The large summit crater, called Mokuaweoweo Caldera, is clearly visible near the center of the image. Leading away from the caldera (towards top right and lower center) are the two main rift zones shown here in orange. Rift zones are areas of weakness within the upper part of the volcano that are often ripped open as new magma (molten rock) approaches the surface at the start of an eruption. The most recent eruption of Mauna Loa was in March and April 1984, when segments of the northeast rift zones were active. If the height of the volcano was measured from its base on the ocean floor instead of from sea level, Mauna Loa would be the tallest mountain on Earth. Its peak (center of the image) rises more than 8 kilometers (5 miles) above the ocean floor. The South Kona District, known for cultivation of macadamia nuts and coffee, can be seen in the lower left as white and blue areas along the coast. North is toward the upper left. The area shown is 41.5 by 75 kilometers (25.7 by 46.5 miles), centered at 19.5 degrees north latitude and 155.6 degrees west longitude. The image was acquired by the Spaceborne Imaging Radar-C/X-Band Synthetic Aperture Radar (SIR-C/ X-SAR) aboard the space shuttle Endeavour on its 36th orbit on October 2, 1994. The radar illumination is from the left of the image. The colors in this image were obtained using the following radar channels: red represents the L-band (horizontally transmitted and received); green represents the L-band (horizontally transmitted, vertically received); blue represents the C-band (horizontally transmitted, vertically received). The resulting color combinations in this radar image are caused by differences in surface roughness of the lava flows. Smoother flows

  3. SPace Radar Image of Fort Irwin, California

    NASA Technical Reports Server (NTRS)

    1994-01-01

    This image of Fort Irwin in California's Mojave Desert compares interferometric radar signatures topography -- data that were obtained by multiple imaging of the same region to produce three-dimensional elevation maps -- as it was obtained on October 7-8, 1994 by the Spaceborne Imaging Radar-C/X-band Synthetic Aperture Radar aboard the space shuttle Endeavour. Data were acquired using the L-band (24 centimeter wavelength) and C-band (6 centimeter wavelength). The image covers an area about 25 kilometers by 70 kilometers (15.5 miles by 43 miles). North is to the lower right of the image. The color contours shown are proportional to the topographic elevation. With a wavelength one-fourth that of the L-band, the results from the C-band cycle through the color contours four times faster for a given elevation change. Detailed comparisons of these multiple frequency data over different terrain types will provide insights in the future into wavelength-dependent effects of penetration and scattering on the topography measurement accuracy. Fort Irwin is an ideal site for such detailed digital elevation model comparisons because a number of high precision digital models of the area already exist from conventional measurements as well as from airborne interferometric SAR data. Spaceborne Imaging Radar-C and X-band Synthetic Aperture Radar (SIR-C/X-SAR) is part of NASA's Mission to Planet Earth. The radars illuminate Earth with microwaves, allowing detailed observations at any time, regardless of weather or sunlight conditions. SIR-C/X-SAR uses three microwave wavelengths: L-band (24 cm), C-band (6 cm) and X-band (3 cm). The multi-frequency data will be used by the international scientific community to better understand the global environment and how it is changing. The SIR-C/X-SAR data, complemented by aircraft and ground studies, will give scientists clearer insights into those environmental changes which are caused by nature and those changes which are induced by human

  4. Spaceborne Radar Study

    DTIC Science & Technology

    1974-06-28

    If comm beam contact is lost, the instrumentation data are sent via the omnichannel transmitter on command of the ground station. There are six ways...comm’beam) at all times except when comm beam contact is lost. A two-way omnidirectional (backup) command link is provided for initial stabilization...via either the oomm beam or the omnichannel . Satellite instrumentation data are sent to the ground station following every radar signal transmission

  5. Shuttle imaging radar experiment

    USGS Publications Warehouse

    Elachi, C.; Brown, W.E.; Cimino, J.B.; Dixon, T.; Evans, D.L.; Ford, J.P.; Saunders, R.S.; Breed, C.; Masursky, H.; McCauley, J.F.; Schaber, G.; Dellwig, L.; England, A.; MacDonald, H.; Martin-Kaye, P.; Sabins, F.

    1982-01-01

    The shuttle imaging radar (SIR-A) acquired images of a variety of the earth's geologic areas covering about 10 million square kilometers. Structural and geomorphic features such as faults, folds, outcrops, and dunes are clearly visible in both tropical and arid regions. The combination of SIR-A and Seasat images provides additional information about the surface physical properties: topography and roughness. Ocean features were also observed, including large internal waves in the Andaman Sea. Copyright ?? 1982 AAAS.

  6. Weather Radar Studies.

    DTIC Science & Technology

    2014-09-26

    and Doppler weather radar data from the National Center for Atmospheric Research JAWS program and the National .Severe Storms Laboratory, are being...Atmospheric Research JAWS program and the National Severe Storms Laboratory, are being analyzed to develop low-altitude wind-shear detection algorithms...pictures, and dusted for fingerprints. The wind sensors, rain gauge, and antenna were destroyed but the DCP, solar panel, and other site components

  7. The Radar Roadmap

    DTIC Science & Technology

    2013-01-01

    LIMITATION OF ABSTRACT Same as Report ( SAR ) 18. NUMBER OF PAGES 25 19a. NAME OF RESPONSIBLE PERSON a. REPORT unclassified b. ABSTRACT unclassified c...ABSTRACT Same as Report ( SAR ) 18. NUMBER OF PAGES 25 19a. NAME OF RESPONSIBLE PERSON a. REPORT unclassified b. ABSTRACT unclassified c. THIS PAGE...object bistatic radars. The former allows high resolution without the use of pulse compression techniques and the latter promises cheaper systems by

  8. Imaging synthetic aperture radar

    DOEpatents

    Burns, Bryan L.; Cordaro, J. Thomas

    1997-01-01

    A linear-FM SAR imaging radar method and apparatus to produce a real-time image by first arranging the returned signals into a plurality of subaperture arrays, the columns of each subaperture array having samples of dechirped baseband pulses, and further including a processing of each subaperture array to obtain coarse-resolution in azimuth, then fine-resolution in range, and lastly, to combine the processed subapertures to obtain the final fine-resolution in azimuth. Greater efficiency is achieved because both the transmitted signal and a local oscillator signal mixed with the returned signal can be varied on a pulse-to-pulse basis as a function of radar motion. Moreover, a novel circuit can adjust the sampling location and the A/D sample rate of the combined dechirped baseband signal which greatly reduces processing time and hardware. The processing steps include implementing a window function, stabilizing either a central reference point and/or all other points of a subaperture with respect to doppler frequency and/or range as a function of radar motion, sorting and compressing the signals using a standard fourier transforms. The stabilization of each processing part is accomplished with vector multiplication using waveforms generated as a function of radar motion wherein these waveforms may be synthesized in integrated circuits. Stabilization of range migration as a function of doppler frequency by simple vector multiplication is a particularly useful feature of the invention; as is stabilization of azimuth migration by correcting for spatially varying phase errors prior to the application of an autofocus process.

  9. Goldstone solar system radar

    NASA Technical Reports Server (NTRS)

    Jurgens, Raymond F.

    1991-01-01

    Caltech/Jet Propulsion Laboratory (JPL) radar astronomers made use of the Very Large Array (VLA) at Socorro, NM, during February 1990, to receive radio echoes from the planet Venus. The transmitter was the 70 meter antenna at the Goldstone complex northwest of Barstow, CA. These observations contain new information about the roughness of Venus at cm to decimeter scales and are complementary to information being obtained by the Magellan spacecraft. Asteroid observations are also discussed.

  10. Cognitive Nonlinear Radar

    DTIC Science & Technology

    2013-01-01

    Devices and Method for Detecting Emplacement of Improvised Explosive Devices, U. S. Patent 7,680,599, Mar. 16, 2010. 11. Steele, D.; Rotondo, F.; Houck...Patent 7,987,068, Jul. 26, 2011. 9 14. Keller, W. Active Improvised Explosive Device (IED) Electronic Signature Detection , U. S. Patent...operate without interfering with each other. The CNR uses a narrowband, nonlinear radar target detection methodology. This methodology has the advantage

  11. Weather Radar Studies.

    DTIC Science & Technology

    1985-03-31

    National Center for Atmospheric Research JAWS program and the National Severe Storms Laboratory are being analyzed to develop low-altitude wind shear...public through low-altitude wind shear aviation weather products the National Technical Information Service, NEXR I turbulence., Springfield, VA 22161. 19...were analyzed preliminarily to determine wind shear characteristics in the Memphis area. Doppler weather radar data from the National Center for

  12. The JERS-1 Amazon Multi-Season Mapping Study (JAMMS)

    NASA Technical Reports Server (NTRS)

    Freeman, A.; Chapman, B.; Alves, M.

    1996-01-01

    Regional mapping of the Amazon basin using imaging radar is described. Two 60-day periods of radar mapping will be conducted, one in 1995, and one in 1996. One period will view the low-water season, and the other will view during the high-flood season. The main objective of the JAMMS project is to generate a regional map showing inundation throughout the Amazon Basin by comparing the two data sets.

  13. Further developments of EISCAT as an MST radar

    NASA Technical Reports Server (NTRS)

    Rottger, J.

    1984-01-01

    The principal capabilities of EISCAT as an MST radar were described. Since the VHF transmitter of the EISCAT system is not yet delivered, only the UHF system could be used for radar experiments. Considerable developments in the year 1983 have now strongly improved the reliability of the operations. Most of the experiments were and will be done to investigate the high latitude ionosphere and thermosphere, but some time was also devoted to observations of the lower and middle atmosphere, particularly during the MAP/WINE compaign.

  14. Proceedings of the Third Airborne Synthetic Aperture Radar (AIRSAR) Workshop

    NASA Technical Reports Server (NTRS)

    Vanzyl, Jakob J. (Editor)

    1991-01-01

    The Third Airborne Synthetic Aperture Radar (AIRSAR) Workshop was held on 23-24 May 1991 at JPL. Thirty oral presentations were made and 18 poster papers displayed during the workshop. Papers from these 25 presentations are presented which include analyses of AIRSAR operations and studies in SAR remote sensing, ecology, hydrology, soil science, geology, oceanography, volcanology, and SAR mapping and data handling. Results from these studies indicate the direction and emphasis of future orbital radar-sensor missions that will be launched during the 1990's.

  15. Radar clutter classification

    NASA Astrophysics Data System (ADS)

    Stehwien, Wolfgang

    1989-11-01

    The problem of classifying radar clutter as found on air traffic control radar systems is studied. An algorithm based on Bayes decision theory and the parametric maximum a posteriori probability classifier is developed to perform this classification automatically. This classifier employs a quadratic discriminant function and is optimum for feature vectors that are distributed according to the multivariate normal density. Separable clutter classes are most likely to arise from the analysis of the Doppler spectrum. Specifically, a feature set based on the complex reflection coefficients of the lattice prediction error filter is proposed. The classifier is tested using data recorded from L-band air traffic control radars. The Doppler spectra of these data are examined; the properties of the feature set computed using these data are studied in terms of both the marginal and multivariate statistics. Several strategies involving different numbers of features, class assignments, and data set pretesting according to Doppler frequency and signal to noise ratio were evaluated before settling on a workable algorithm. Final results are presented in terms of experimental misclassification rates and simulated and classified plane position indicator displays.

  16. Radar gun hazards

    SciTech Connect

    Not Available

    1991-12-20

    Radar guns - hand-held units used by the law to nail speeders - have been in use since the early '60s. Now they've been accused of causing cancer. Police officers in several states have so far filed eight suits against the manufacturer, claiming that they have contracted rare forms of cancer, such as of the eyelid and the testicle, from frequent proximity to the devices. Spurred by concerns expressed by police groups, researchers at the Rochester Institute of Technology are conducting what they believe to be the first research of its kind in the nation. Last month psychologist John Violanti, an expert in policy psychology and health, sent out a one-page survey to 6,000 active and retired police officers in New York State, asking them about their health and their use of radar guns. Violanti says melanoma, leukemia, and lymph node cancer may be linked to these as well as other electromagnetic devices. The Food and Drug Administration earlier this year issued a warning about radar guns, telling users not to operate them closer than 6 inches from the body. But this may not be a sufficient safeguard since the instruments can give off crisscrossing wave emissions within a police vehicle. The survey will be used to help determine if it would be safer to mount the guns, which are currently either hand-held or mounted on dashboards, outside troopers' cars.

  17. Nordic Snow Radar Experiment

    NASA Astrophysics Data System (ADS)

    Lemmetyinen, Juha; Kontu, Anna; Pulliainen, Jouni; Vehviläinen, Juho; Rautiainen, Kimmo; Wiesmann, Andreas; Mätzler, Christian; Werner, Charles; Rott, Helmut; Nagler, Thomas; Schneebeli, Martin; Proksch, Martin; Schüttemeyer, Dirk; Kern, Michael; Davidson, Malcolm W. J.

    2016-09-01

    The objective of the Nordic Snow Radar Experiment (NoSREx) campaign was to provide a continuous time series of active and passive microwave observations of snow cover at a representative location of the Arctic boreal forest area, covering a whole winter season. The activity was a part of Phase A studies for the ESA Earth Explorer 7 candidate mission CoReH2O (Cold Regions Hydrology High-resolution Observatory). The NoSREx campaign, conducted at the Finnish Meteorological Institute Arctic Research Centre (FMI-ARC) in Sodankylä, Finland, hosted a frequency scanning scatterometer operating at frequencies from X- to Ku-band. The radar observations were complemented by a microwave dual-polarization radiometer system operating from X- to W-bands. In situ measurements consisted of manual snow pit measurements at the main test site as well as extensive automated measurements on snow, ground and meteorological parameters. This study provides a summary of the obtained data, detailing measurement protocols for each microwave instrument and in situ reference data. A first analysis of the microwave signatures against snow parameters is given, also comparing observed radar backscattering and microwave emission to predictions of an active/passive forward model. All data, including the raw data observations, are available for research purposes through the European Space Agency and the Finnish Meteorological Institute. A consolidated dataset of observations, comprising the key microwave and in situ observations, is provided through the ESA campaign data portal to enable easy access to the data.

  18. Geologic map of Mars

    USGS Publications Warehouse

    Tanaka, Kenneth L.; Skinner, James A.; Dohm, James M.; Irwin, Rossman P.; Kolb, Eric J.; Fortezzo, Corey M.; Platz, Thomas; Michael, Gregory G.; Hare, Trent M.

    2014-01-01

    This global geologic map of Mars, which records the distribution of geologic units and landforms on the planet's surface through time, is based on unprecedented variety, quality, and quantity of remotely sensed data acquired since the Viking Orbiters. These data have provided morphologic, topographic, spectral, thermophysical, radar sounding, and other observations for integration, analysis, and interpretation in support of geologic mapping. In particular, the precise topographic mapping now available has enabled consistent morphologic portrayal of the surface for global mapping (whereas previously used visual-range image bases were less effective, because they combined morphologic and albedo information and, locally, atmospheric haze). Also, thermal infrared image bases used for this map tended to be less affected by atmospheric haze and thus are reliable for analysis of surface morphology and texture at even higher resolution than the topographic products.

  19. High-resolution instrumentation radar

    NASA Astrophysics Data System (ADS)

    Dydbal, Robert B.; Hurlbut, Keith H.; Mori, Tsutomu T.

    1987-03-01

    An instrumentation radar that uses a chirp waveform to achieve high-range resolution is described. High-range-resolution instrumentation radars evaluate the target response to operational waveforms used in high-performance radars and/or obtain a display of the individual target scattering mechanisms to better understand the scattering process. This particular radar was efficiently constructed from a combination of commercially available components and in-house fabricated circuitry. This instrumentation radar operates at X-band and achieves a 4.9-in-range resolution. A key feature of the radar is the combination of amplitude weighting with a high degree of waveform fidelity to achieve a very good range sidelobe performance. This range sidelobe performance is important to avoid masking lower level target returns in the range sidelobes of higher target returns.

  20. The Shuttle Radar Topography Mission: A Global DEM

    NASA Technical Reports Server (NTRS)

    Farr, Tom G.; Kobrick, Mike

    2000-01-01

    Digital topographic data are critical for a variety of civilian, commercial, and military applications. Scientists use Digital Elevation Models (DEM) to map drainage patterns and ecosystems, and to monitor land surface changes over time. The mountain-building effects of tectonics and the climatic effects of erosion can also be modeled with DEW The data's military applications include mission planning and rehearsal, modeling and simulation. Commercial applications include determining locations for cellular phone towers, enhanced ground proximity warning systems for aircraft, and improved maps for backpackers. The Shuttle Radar Topography Mission (SRTM) (Fig. 1), is a cooperative project between NASA and the National Imagery and Mapping Agency (NIMA) of the U.S. Department of Defense. The mission is designed to use a single-pass radar interferometer to produce a digital elevation model of the Earth's land surface between about 60 degrees north and south latitude. The DEM will have 30 m pixel spacing and about 15 m vertical errors.

  1. Radar-aeolian roughness project

    NASA Technical Reports Server (NTRS)

    Greeley, Ronald; Dobrovolskis, A.; Gaddis, L.; Iversen, J. D.; Lancaster, N.; Leach, Rodman N.; Rasnussen, K.; Saunders, S.; Vanzyl, J.; Wall, S.

    1991-01-01

    The objective is to establish an empirical relationship between measurements of radar, aeolian, and surface roughness on a variety of natural surfaces and to understand the underlying physical causes. This relationship will form the basis for developing a predictive equation to derive aeolian roughness from radar backscatter. Results are given from investigations carried out in 1989 on the principal elements of the project, with separate sections on field studies, radar data analysis, laboratory simulations, and development of theory for planetary applications.

  2. Radar studies of bird migration

    NASA Technical Reports Server (NTRS)

    Williams, T. C.; Williams, J. M.

    1974-01-01

    Observations of bird migration with NASA radars were made at Wallops Island, Va. Simultaneous observations were made at a number of radar sites in the North Atlantic Ocean in an effort to discover what happened to those birds that were observed leaving the coast of North America headed toward Bermuda, the Caribbean and South America. Transatlantic migration, utilizing observations from a large number of radars is discussed. Detailed studies of bird movements at Wallops Island are presented.

  3. Radar Studies of Aviation Hazards

    DTIC Science & Technology

    1994-05-31

    4. TITLE AND SURTITLE S. FUNDING NUMBERS RADAR STUDIES OF AVIATION HAZARDS F1 9628-93- C -0054 _____________ __PE63707F 6. AUTHOR(S) PR278 1...foilowing processing steps have been adopted: a. acquire single scan radar data, b. distinguish individual storms, c . eliminate spurious data for...occurred only with radar reflectivities above 40 dBZ at the -10° C level and cloud tops above the -200C level. Lightning occurred only when tops extended

  4. Rapid and Robust Damage Detection using Radar Remote Sensing

    NASA Astrophysics Data System (ADS)

    Yun, S.; Fielding, E. J.; Simons, M.; Webb, F.; Rosen, P. A.; Owen, S. E.

    2012-12-01

    Under ARIA (Advanced Rapid Imaging and Analysis) project at JPL and Caltech, we developed a prototype algorithm and data system to rapidly detect surface change caused by natural or man-made damage using a radar remote sensing technique of InSAR coherence. We tested the algorithm with a building demolition site in the City of Pasadena, California. The results show clear signal at the demolition site, with about 150% SNR improvement compared to conventional approach. Out of fourteen strongest detected signals, we confirmed that at least eleven of them were associated with real demolition and construction projects. We applied the algorithm to the February 2011 M6.3 Christchurch earthquake in New Zealand, which killed 185 people and caused financial damage of US $16-24 billion. We produced a damage proxy map (DPM) using radar data from ALOS satellite (Figure A), where red pixels identify regions where there may have been earthquake induced building damage, landslides, and liquefaction. The distribution of the red regions agrees well with the post-earthquake assessment performed on the ground by inspectors from the New Zealand government and summarized in their damage assessment zone map (Figure B). The DPM was derived from radar data acquired 3 days after the earthquake, whereas the ground truth zone map was first published 4 months after the earthquake. In addition to all-weather and day-and-night capability of radar, the sensitivity of radar signal to surface property change is high enough for reliable damage assessment. Current and future satellite and airborne missions should keep the expected composite data acquisition latency within a day. Rapidly produced accurate damage assessment maps will help saving people, assisting effective prioritization of rescue operations at early stage of response, and significantly improve timely situational awareness for emergency management and national / international assessment for response and recovery.

  5. Earth-based Radar Observations of Mercury: Imaging Results with the Upgraded Arecibo Radar

    NASA Astrophysics Data System (ADS)

    Harmon, J.

    With the completion of the Arecibo upgrade in 1998 came the opportunity to do Mercury radar imaging of unprecedented quality. Among the early results with the upgraded S-band radar was the delay-Doppler imaging of the north polar ice features at 1.5-km resolution (Harmon et al., 2001). These images provided accurate mapping of the putative ice deposits within shaded crater floors as well as a precise determination of the pole position. They also produced the surprising discovery of ice features in small craters and at relatively low latitudes, which places important constraints on thermal models. We are also planning imaging observations of the south pole as it returns to view in 2004 and subsequent years. Besides polar studies, an important component of the Arecibo program is full-disk radar imaging around the entire planet, with a special emphasis on the hemisphere left unimaged by Mariner 10. For this purpose we are conducting a program of delay-Doppler observations using the long-code method (Harmon, 2002), which produces cleaner images than conventional delay-Doppler. Most striking are the depolarized images, which are found to be dominated by bright features associated with fresh crater ejecta. These images show some spectacular rayed craters in the Tycho class, as well as numerous bright, rayless features from smaller impacts. Also visible are some diffuse albedo features with no obvious impact association. Some of these high-albedo patches are found in smooth plains regions such as Tolstoy basin and Tir Planitia, which is the reverse of the mare-highland contrast seen in radar images of the Moon. In addition to the imaging results, we will briefly review the major findings from the pre-upgrade radar altimetry measurements.

  6. Reconfigurable L-Band Radar

    NASA Technical Reports Server (NTRS)

    Rincon, Rafael F.

    2008-01-01

    The reconfigurable L-Band radar is an ongoing development at NASA/GSFC that exploits the capability inherently in phased array radar systems with a state-of-the-art data acquisition and real-time processor in order to enable multi-mode measurement techniques in a single radar architecture. The development leverages on the L-Band Imaging Scatterometer, a radar system designed for the development and testing of new radar techniques; and the custom-built DBSAR processor, a highly reconfigurable, high speed data acquisition and processing system. The radar modes currently implemented include scatterometer, synthetic aperture radar, and altimetry; and plans to add new modes such as radiometry and bi-static GNSS signals are being formulated. This development is aimed at enhancing the radar remote sensing capabilities for airborne and spaceborne applications in support of Earth Science and planetary exploration This paper describes the design of the radar and processor systems, explains the operational modes, and discusses preliminary measurements and future plans.

  7. Python-ARM Radar Toolkit

    SciTech Connect

    Jonathan Helmus, Scott Collis

    2013-03-17

    The Python-ARM Radar Toolkit (Py-ART) is a collection of radar quality control and retrieval codes which all work on two unifying Python objects: the PyRadar and PyGrid objects. By building ingests to several popular radar formats and then abstracting the interface Py-ART greatly simplifies data processing over several other available utilities. In addition Py-ART makes use of Numpy arrays as its primary storage mechanism enabling use of existing and extensive community software tools.

  8. Observations of the marine environment from spaceborne side-looking real aperture radars

    NASA Technical Reports Server (NTRS)

    Kalmykov, A. I.; Velichko, S. A.; Tsymbal, V. N.; Kuleshov, Yu. A.; Weinman, J. A.; Jurkevich, I.

    1993-01-01

    Real aperture, side looking X-band radars have been operated from the Soviet Cosmos-1500, -1602, -1766 and Ocean satellites since 1984. Wind velocities were inferred from sea surface radar scattering for speeds ranging from approximately 2 m/s to those of hurricane proportions. The wind speeds were within 10-20 percent of the measured in situ values, and the direction of the wind velocity agreed with in situ direction measurements within 20-50 deg. Various atmospheric mesoscale eddies and tropical cyclones were thus located, and their strengths were inferred from sea surface reflectivity measurements. Rain cells were observed over both land and sea with these spaceborne radars. Algorithms to retrieve rainfall rates from spaceborne radar measurements were also developed. Spaceborne radars have been used to monitor various marine hazards. For example, information derived from those radars was used to plan rescue operations of distressed ships trapped in sea ice. Icebergs have also been monitored, and oil spills were mapped. Tsunamis produced by underwater earthquakes were also observed from space by the radars on the Cosmos 1500 series of satellites. The Cosmos-1500 satellite series have provided all weather radar imagery of the earths surface to a user community in real time by means of a 137.4 MHz Automatic Picture Transmission channel. This feature enabled the radar information to be used in direct support of Soviet polar maritime activities.

  9. Bird migration flight altitudes studied by a network of operational weather radars.

    PubMed

    Dokter, Adriaan M; Liechti, Felix; Stark, Herbert; Delobbe, Laurent; Tabary, Pierre; Holleman, Iwan

    2011-01-06

    A fully automated method for the detection and quantification of bird migration was developed for operational C-band weather radar, measuring bird density, speed and direction as a function of altitude. These weather radar bird observations have been validated with data from a high-accuracy dedicated bird radar, which was stationed in the measurement volume of weather radar sites in The Netherlands, Belgium and France for a full migration season during autumn 2007 and spring 2008. We show that weather radar can extract near real-time bird density altitude profiles that closely correspond to the density profiles measured by dedicated bird radar. Doppler weather radar can thus be used as a reliable sensor for quantifying bird densities aloft in an operational setting, which--when extended to multiple radars--enables the mapping and continuous monitoring of bird migration flyways. By applying the automated method to a network of weather radars, we observed how mesoscale variability in weather conditions structured the timing and altitude profile of bird migration within single nights. Bird density altitude profiles were observed that consisted of multiple layers, which could be explained from the distinct wind conditions at different take-off sites. Consistently lower bird densities are recorded in The Netherlands compared with sites in France and eastern Belgium, which reveals some of the spatial extent of the dominant Scandinavian flyway over continental Europe.

  10. Millimeter Wave Cloud Radar (MMCR) Handbook

    SciTech Connect

    KB Widener; K Johnson

    2005-01-30

    The millimeter cloud radar (MMCR) systems probe the extent and composition of clouds at millimeter wavelengths. The MMCR is a zenith-pointing radar that operates at a frequency of 35 GHz. The main purpose of this radar is to determine cloud boundaries (e.g., cloud bottoms and tops). This radar will also report radar reflectivity (dBZ) of the atmosphere up to 20 km. The radar possesses a doppler capability that will allow the measurement of cloud constituent vertical velocities.

  11. Removing interfering clutter associated with radar pulses that an airborne radar receives from a radar transponder

    DOEpatents

    Ormesher, Richard C.; Axline, Robert M.

    2008-12-02

    Interfering clutter in radar pulses received by an airborne radar system from a radar transponder can be suppressed by developing a representation of the incoming echo-voltage time-series that permits the clutter associated with predetermined parts of the time-series to be estimated. These estimates can be used to estimate and suppress the clutter associated with other parts of the time-series.

  12. Evaluation of hail suppression programme effectiveness using radar derived parameters

    NASA Astrophysics Data System (ADS)

    Tani, Satyanarayana; Paulitsch, Helmut; Teschl, Reinhard; Süsser-Rechberger, Barbara

    2016-04-01

    The objective of this study is evaluating "the operational hail suppression programme" in the province of Styria, Austria "for the year 2015". For the evaluation purpose the HAILSYS software tool was developed by integrating single polarization C-band weather radar data, aircraft trajectory, radiosonde freezing level data, hail events and crop damages information from the ground. The hail related radar derived parameters are: hail mass aloft, hail mass flux, probability of hail, vertical integrated hail mass, hail kinetic energy flux, and storm severity index. The spatial maps of hail kinetic energy and hail mass were developed to evaluate the seeding effect. The time history plots of vertical integrated hail mass, hail mass aloft and the probability of hail are drawn over an entire cell lifetime. The sensitivity and variation of radar hail parameters over time and associated changes due to cloud seeding will be presented.

  13. The Shuttle Imaging Radar B (SIR-B) experiment report

    NASA Technical Reports Server (NTRS)

    Cimino, Jo Bea; Holt, Benjamin; Richardson, Annie

    1988-01-01

    The primary objective of the SIR-B experiment was to acquire multiple-incidence-angle radar imagery of a variety of Earth's surfaces to better understand the effects of imaging geometry on radar backscatter. A complementary objective was to map extensive regions of particular interest. Under these broad objectives, many specific scientific experiments were defined by the 43 SIR-B Science Team members, including studies in the area of geology, vegetation, radar penetration, oceanography, image analysis, and calibration technique development. Approximately 20 percent of the planned digital data were collected, meeting 40 percent of the scientific objectives. This report is an overview of the SIR-B experiment and includes the science investigations, hardware design, mission scenario, mission operations, events of the actual missions, astronaut participation, data products (including auxiliary data), calibrations, and a summary of the actual coverage. Also included are several image samples.

  14. High-frequency radar observations of ocean surface currents.

    PubMed

    Paduan, Jeffrey D; Washburn, Libe

    2013-01-01

    This article reviews the discovery, development, and use of high-frequency (HF) radio wave backscatter in oceanography. HF radars, as the instruments are commonly called, remotely measure ocean surface currents by exploiting a Bragg resonant backscatter phenomenon. Electromagnetic waves in the HF band (3-30 MHz) have wavelengths that are commensurate with wind-driven gravity waves on the ocean surface; the ocean waves whose wavelengths are exactly half as long as those of the broadcast radio waves are responsible for the resonant backscatter. Networks of HF radar systems are capable of mapping surface currents hourly out to ranges approaching 200 km with a horizontal resolution of a few kilometers. Such information has many uses, including search and rescue support and oil-spill mitigation in real time and larval population connectivity assessment when viewed over many years. Today, HF radar networks form the backbone of many ocean observing systems, and the data are assimilated into ocean circulation models.

  15. Space Radar Image of Long Valley, California in 3-D

    NASA Technical Reports Server (NTRS)

    1994-01-01

    This three-dimensional perspective view of Long Valley, California was created from data taken by the Spaceborne Imaging Radar-C/X-band Synthetic Aperture Radar on board the space shuttle Endeavour. This image was constructed by overlaying a color composite SIR-C radar image on a digital elevation map. The digital elevation map was produced using radar interferometry, a process by which radar data are acquired on different passes of the space shuttle. The two data passes are compared to obtain elevation information. The interferometry data were acquired on April 13,1994 and on October 3, 1994, during the first and second flights of the SIR-C/X-SAR instrument. The color composite radar image was taken in October and was produced by assigning red to the C-band (horizontally transmitted and vertically received) polarization; green to the C-band (vertically transmitted and received) polarization; and blue to the ratio of the two data sets. Blue areas in the image are smooth and yellow areas are rock outcrops with varying amounts of snow and vegetation. The view is looking north along the northeastern edge of the Long Valley caldera, a volcanic collapse feature created 750,000 years ago and the site of continued subsurface activity. Crowley Lake is the large dark feature in the foreground. Spaceborne Imaging Radar-C and X-band Synthetic Aperture Radar (SIR-C/X-SAR) is part of NASA's Mission to Planet Earth. The radars illuminate Earth with microwaves, allowing detailed observations at any time, regardless of weather or sunlight conditions. SIR-C/X-SAR uses three microwave wavelengths: L-band (24 cm), C-band (6 cm) and X-band (3 cm). The multi-frequency data will be used by the international scientific community to better understand the global environment and how it is changing. The SIR-C/X-SAR data, complemented by aircraft and ground studies, will give scientists clearer insights into those environmental changes which are caused by nature and those changes which are

  16. The SHARAD Sounding Radar Explores Mars (Invited)

    NASA Astrophysics Data System (ADS)

    Phillips, R. J.; Seu, R.; Campbell, B. A.; Plaut, J. J.; Holt, J. W.; Carter, L. M.; Putzig, N. E.; Smrekar, S. E.; Nunes, D. C.; Orosei, R.

    2009-12-01

    SHARAD (SHAllow RADar) is a sounding radar provided by the Italian Space Agency for the Mars Reconnaissance Orbiter mission. Its 20-MHz center frequency and 10-MHz bandwidth complement the lower frequency and narrower bandwidth of the MARSIS sounding radar. SHARAD is particularly useful for mapping the internal, fine-scale layering of the deposits in the polar regions of Mars. In the north, SHARAD paints a three-dimensional picture of the stratigraphy, previously mapped from visible images only in canyon exposures on the periphery of the cap. Regional differences in elevation across the cap are caused by a coarsely layered, variable thickness Basal Unit partially underlying a relatively constant thickness (~2-km) ice-rich layered unit. Of particular interest are the subsurface patterns of ice and dust layers, which are likely tied to the martian climate history over the last several million years and thus to time variations in the planet’s orbit and in its spin-axis obliquity and precession. In the layered deposits at both poles SHARAD has mapped angular unconformities, and at the northern cap SHARAD has unraveled the stratigraphic records of trough migration. The subsurface structures of the ice-rich layered deposits are on the whole different between the two poles, and this may reflect their age difference. The radars have also mapped subsurface reflections in other areas of Mars, including many locales in the northern lowlands. In southern Elysium Planitia, some have interpreted the geomorphology seen in imagery in terms of a frozen sea, but SHARAD shows that the electrical properties of the shallow subsurface material in this region are inconsistent with ice. Elsewhere, geological evidence points to the possibility of ice-rich deposits (such as lobate debris aprons) at mid-latitudes, relics of past glaciations driven by high obliquities. Here, SHARAD confirms the ice hypothesis based on the dielectric behavior of the subsurface material. A subsurface

  17. Broadview Radar Altimetry Toolbox

    NASA Astrophysics Data System (ADS)

    Mondéjar, Albert; Benveniste, Jérôme; Naeije, Marc; Escolà, Roger; Moyano, Gorka; Roca, Mònica; Terra-Homem, Miguel; Friaças, Ana; Martinho, Fernando; Schrama, Ernst; Ambrózio, Américo; Restano, Marco

    2016-07-01

    The universal altimetry toolbox, BRAT (Broadview Radar Altimetry Toolbox) which can read all previous and current altimetry missions' data, incorporates now the capability to read the upcoming Sentinel-3 L1 and L2 products. ESA endeavoured to develop and supply this capability to support the users of the future Sentinel-3 SAR Altimetry Mission. BRAT is a collection of tools and tutorial documents designed to facilitate the processing of radar altimetry data. This project started in 2005 from the joint efforts of ESA (European Space Agency) and CNES (Centre National d'Études Spatiales), and it is freely available at http://earth.esa.int/brat. The tools enable users to interact with the most common altimetry data formats. The BratGUI is the front-end for the powerful command line tools that are part of the BRAT suite. BRAT can also be used in conjunction with MATLAB/IDL (via reading routines) or in C/C++/Fortran via a programming API, allowing the user to obtain desired data, bypassing the data-formatting hassle. BRAT can be used simply to visualise data quickly, or to translate the data into other formats such as NetCDF, ASCII text files, KML (Google Earth) and raster images (JPEG, PNG, etc.). Several kinds of computations can be done within BRAT involving combinations of data fields that the user can save for posterior reuse or using the already embedded formulas that include the standard oceanographic altimetry formulas. The Radar Altimeter Tutorial, that contains a strong introduction to altimetry, shows its applications in different fields such as Oceanography, Cryosphere, Geodesy, Hydrology among others. Included are also "use cases", with step-by-step examples, on how to use the toolbox in the different contexts. The Sentinel-3 SAR Altimetry Toolbox shall benefit from the current BRAT version. While developing the toolbox we will revamp of the Graphical User Interface and provide, among other enhancements, support for reading the upcoming S3 datasets and

  18. Broadview Radar Altimetry Toolbox

    NASA Astrophysics Data System (ADS)

    Escolà, Roger; Garcia-Mondejar, Albert; Moyano, Gorka; Roca, Mònica; Terra-Homem, Miguel; Friaças, Ana; Martinho, Fernando; Schrama, Ernst; Naeije, Marc; Ambrozio, Americo; Restano, Marco; Benveniste, Jérôme

    2016-04-01

    The universal altimetry toolbox, BRAT (Broadview Radar Altimetry Toolbox) which can read all previous and current altimetry missions' data, incorporates now the capability to read the upcoming Sentinel-3 L1 and L2 products. ESA endeavoured to develop and supply this capability to support the users of the future Sentinel-3 SAR Altimetry Mission. BRAT is a collection of tools and tutorial documents designed to facilitate the processing of radar altimetry data. This project started in 2005 from the joint efforts of ESA (European Space Agency) and CNES (Centre National d'Etudes Spatiales), and it is freely available at http://earth.esa.int/brat. The tools enable users to interact with the most common altimetry data formats. The BratGUI is the front-end for the powerful command line tools that are part of the BRAT suite. BRAT can also be used in conjunction with MATLAB/IDL (via reading routines) or in C/C++/Fortran via a programming API, allowing the user to obtain desired data, bypassing the data-formatting hassle. BRAT can be used simply to visualise data quickly, or to translate the data into other formats such as NetCDF, ASCII text files, KML (Google Earth) and raster images (JPEG, PNG, etc.). Several kinds of computations can be done within BRAT involving combinations of data fields that the user can save for posterior reuse or using the already embedded formulas that include the standard oceanographic altimetry formulas. The Radar Altimeter Tutorial, that contains a strong introduction to altimetry, shows its applications in different fields such as Oceanography, Cryosphere, Geodesy, Hydrology among others. Included are also "use cases", with step-by-step examples, on how to use the toolbox in the different contexts. The Sentinel-3 SAR Altimetry Toolbox shall benefit from the current BRAT version. While developing the toolbox we will revamp of the Graphical User Interface and provide, among other enhancements, support for reading the upcoming S3 datasets and

  19. Orbital Synthetic Aperture Radar (SAR) for Mars Post Sample Return Exploration

    NASA Technical Reports Server (NTRS)

    Thompson, T. W.; Plaut, J. J.; Arvidson, R. E.; Paillou, P.

    2000-01-01

    A Mars orbital radar mission would use two frequencies to map the planet at 50 m resolution, penetrating 5-10 m. Some areas will be imaged at 5-m resolution. A 50-m resolution topographic map will be acquired, and surface changes detected.

  20. Radar Interferometry Detection of Hinge Line Migration on Rutford Ice Stream and Carlson Inlet, Antarctica

    NASA Technical Reports Server (NTRS)

    Rignot, Eric

    1997-01-01

    Satellite synthetic-aperture radar (SAR) Interferometry is employed to map the hinge line, or limit of tidal flexing, of Rutford Ice Stream and Carlson Inlet, Antarctica, and detect its migration between 1992 and 1996. The hinge line is mapped using a model fit from an elastic beam theory.

  1. Interferometric radar measurements

    NASA Astrophysics Data System (ADS)

    Smith, Ronald A.; Shipman, Mark; Holder, E. J.; Williams, James K.

    2002-08-01

    The United States Army Space and Missile Defense Command (USASMDC) has interest in a technology demonstration that capitalizes on investment in fire control and smart interceptor technologies that have matured beyond basic research. The concept SWORD (Short range missile defense With Optimized Radar Distribution) consists of a novel approach utilizing a missile interceptor and interferometric fire control radar. A hit-to-kill, closed-loop, command guidance scheme is planned that takes advantage of extremely accurate target and interceptor state vectors derived via the fire control radar. The fire control system has the capability to detect, track, and classify multiple threats in a tactical regime as well as simultaneously provide command guidance updates to multiple missile interceptors. The missile interceptor offers a cost reduction potential as well as an enhancement to the kinematics range and lethality over existing SHORAD systems. Additionally, the Radio Frequency (RF) guidance scheme offers increased battlefield weather performance. The Air Defense (AD) community, responding to current threat capabilities and trends, has identified an urgent need to have a capability to counter proliferated, low cost threats with a low cost-per-kill weapon system. The SWORD system will offer a solution that meets this need. The SWORD critical technologies will be identified including a detailed description of each. Validated test results and basic principles of operation will be presented to prove the merit of past investments. The Deputy Assistant Secretary of the Army for Research and Technology (DAS(R&T) has a three- year Science and Technology Program to evaluate the errors and proposed mitigation techniques associated with target spectral dispersion and range gate straddle. Preliminary bench-top experiment results will be presented in this paper.

  2. RADAR "SAIL" satellite concept

    NASA Astrophysics Data System (ADS)

    Aguttes, Jean Paul; Sombrin, Jacques; Conde, Eric

    1996-11-01

    The Radar SAIL concept is based on the use of a rectangular antenna lying in the dawn-dusk orbital plane with the length (along speed vector) smaller than the height. Such geometry makes it possible to place the solar cells on the back of the antenna, to use gravity gradient stabilisation, and to implement multipath-free GPS interferometric measurement of the antenna deformation thus allowing structural relaxation. Less obviously, the geometry favours the RADAR design too, by allowing grating lobes and therefore a lower density of built-in electronic in the active antenna. The antenna can be thin and packed for launch inside a cylinder-shaped bus having pyrotechnic doors for the antenna deployement and bearing the rest of the payload and the service equipment. With respect to a standard design of performant missions, cost savings come from the bus, whose functions (AOCS, power supply) are simplified, from the launch since the mass budget and the stowing configuration become compatible with medium size rockets (LLV2/3, DELTA-LITE, LM-4.), and from the active antenna built-in electronics. The RADAR SAIL concept is all the more cost effective when the mission requires a large, high and short antenna, i.e. high resolution (<5m), low frequency band (L or S or even P), high revisiting, multiple frequencies. Mission implementation and funding can be favored by the new capability to share the satellite between autonomous regional operators. Combined with ground DBF (digital beam forming) technique, the concept allows extremely simple and low cost missions providing a fixed wide swath (10 to 15 m resolution within 500km to 1000 km swath) for systematic surveillance or monitoring.

  3. The role of space borne imaging radars in environmental monitoring: Some shuttle imaging radar results in Asia

    NASA Technical Reports Server (NTRS)

    Imhoff, M.; Vermillion, C.

    1986-01-01

    The synoptic view afforded by orbiting Earth sensors can be extremely valuable for resource evaluation, environmental monitoring and development planning. For many regions of the world, however, cloud cover has prevented the acquisition of remotely sensed data during the most environmentally stressful periods of the year. This paper discusses how synthetic aperture imaging radar can be used to provide valuable data about the condition of the Earth's surface during periods of bad weather. Examples are given of applications using data from the Shuttle Imaging Radars (SIR) A and B for agriculture land use and crop condition assessment, monsoon flood boundary and flood damage assessment, water resource monitoring and terrain modeling, coastal forest mapping and vegetation penetration, and coastal development monitoring. Recent SIR-B results in Bangladesh are emphasized, radar system basics are reviewed and future SAR systems discussed.

  4. The role of space borne imaging radars in environmental monitoring: Some shuttle imaging radar results in Asia

    NASA Technical Reports Server (NTRS)

    Imhoff, Marc L.; Vermillion, C. H.

    1986-01-01

    The synoptic view afforded by orbiting Earth sensors can be extremely valuable for resource evaluation, environmental monitoring and development planning. For many regions of the world, however, cloud cover has prevented the acquisition of remotely sensed data during the most environmentally stressful periods of the year. How synthetic aperture imaging radar can be used to provide valuable data about the condition of the Earth's surface during periods of bad weather is discussed. Examples are given of applications using data from the Shuttle Imaging Radars (SIR) A and B for agricultural land use and crop condition assessment, monsoon flood boundary and flood damage assessment, water resource monitoring and terrain modeling, coastal forest mapping and vegetation penetration, and coastal development monitoring. Recent SIR-B results in Bangladesh are emphasized, radar system basics are reviewed and future SAR systems are discussed.

  5. Doppler radar flowmeter

    DOEpatents

    Petlevich, Walter J.; Sverdrup, Edward F.

    1978-01-01

    A Doppler radar flowmeter comprises a transceiver which produces an audio frequency output related to the Doppler shift in frequency between radio waves backscattered from particulate matter carried in a fluid and the radiated radio waves. A variable gain amplifier and low pass filter are provided for amplifying and filtering the transceiver output. A frequency counter having a variable triggering level is also provided to determine the magnitude of the Doppler shift. A calibration method is disclosed wherein the amplifier gain and frequency counter trigger level are adjusted to achieve plateaus in the output of the frequency counter and thereby allow calibration without the necessity of being able to visually observe the flow.

  6. A Study of the Use of Meteorological Satellite, Weather Radar, and Integrated Graphics Products in the Flight Service Station System.

    DTIC Science & Technology

    1980-04-01

    watershed hydrological estimates, tops maps, and a vertically integrated liquid water content (VIL) map. System movement vectors are computed, and a flash ... flood monitor is maintained. The maps produced are not exact images of the picture seen on the radar CRT, but rather are processed data presented on

  7. Cassini RADAR Observations of Saturn's Largest Moon, Titan

    NASA Astrophysics Data System (ADS)

    Hayes, A. G., Jr.; Mastrogiuseppe, M.; Lunine, J. I.; Lorenz, R. D.; Wall, S. D.; Stiles, B. W.; Kirk, R. L.; Elachi, C.; Hofgartner, J. D.; Birch, S. P.; Le Gall, A. A.; Poggiali, V.; Zebker, H. A.

    2015-12-01

    The Cassini RADAR is a versatile instrument capable of operating in imaging, altimetry, scatterometry, radiometry, and, most recently, sounding modes. Despite vastly different material properties and environmental conditions, Titan's methane-based hydrologic system drives climatic and geologic processes that result in morphologic features with striking similarity to terrestrial counterparts, including vast equatorial dune fields, well-organized channel networks that route material through erosional and depositional landscapes defining source-to-sink sediment transport systems, and, perhaps most astonishingly, lakes and seas filled with liquid hydrocarbons. Using its various operating modes, the Cassini RADAR has provided a wealth of information regarding Titan's active surface-atmosphere system. In Synthetic Aperture Radar (SAR) mode, the RADAR has unveiled Titan's surface by producing backscatter maps with pixel scales of ~300 m. In altimetry mode, the RADAR has shown the elevation profile of surface features, including the liquid elevation of Titan's lakes and seas, revealed the roughness characteristics of the surface, and constrained the global shape. Most recently, the altimetry mode has doubled as a radar sounder that has successfully probed the depth and absorptivity of the lakes and seas. Data from the scatterometry and radiometry modes have been used to constrain material properties, including dielectric constants and volume scattering fractions, surface texture, and derive seasonal and diurnal temperature variations. Collectively, these datasets have revealed Titan's strange yet familiar nature, and demonstrated that it is one of the most compelling targets in our solar system. During our presentation, we will summarize these capabilities and review some of the most specular discoveries made by the Cassini RADAR.

  8. Identification of Geometrical Structural Changes in Agriculture by Optical and Radar Data

    NASA Astrophysics Data System (ADS)

    Surek, Gyorgy; Nador, Gizella; Akos Gera, David; Hubik, Iren; Kulesar Aniko, Rotterne; Torok, Cecilia

    2013-08-01

    The objective of the project was to monitor the temporal behaviour of geometrical structural change of cropland affected by four different damages: weed infection, Western Corn Rootworm (WCR), storm damage and drought by optical and radar time series data. Based on our preliminary results it is established that ragweed infection in sunflower can be well identified by evaluation of radar (acquired in mid-June) and optical (mid-August) satellite images. Effect of drought in sunflower is well recognizable by spectral indexes from optical, as well as "I"-component of Shannon entropy (SEI) derived from radar satellite images. Detecting damage caused by WCR and storm in maize field is the most efficient by evaluation of radar and optical satellite images acquired in late-July. Components of Shannon entropy have significant role in identification. This project demonstrates the potential of integrated usage of polarimetric radar and optical satellite images for mapping several types of damages in agriculture.

  9. Radar Studies on Kamb Ice Stream

    NASA Astrophysics Data System (ADS)

    Pettersson, R.; Osterhouse, D. J.; Mulhausen, A.; Welch, B. C.; Strandli, C. W.; Jacobel, R. W.

    2006-12-01

    During the past two Antarctic field seasons we acquired approximately 1600 km of ground-based ice- penetrating radar data on the lower trunk of Kamb Ice Stream (KIS) as part of radar, GPS and modeling study with scientists at the University of California Santa Cruz examining the possibility of ice stream reactivation. We present here a summary of radar results from this work and preliminary interpretations. Our working hypothesis is that the reactivation of the stagnant KIS may be triggered by excess influx of basal water produced by increased basal strain heating when mass builds up in the upper reaches of the locked ice stream. Using radar data, we have quantified variations in the amplitude of radar reflections from the ice-bed interface to estimate different provenances of occurrence of basal water. The weakest-reflecting ice-bed interface is found at a "sticky spot" in the middle of the ice stream trunk where ice appears to have become grounded over a large bedrock bump. At the sticky spot, bore holes drilled by California Technical Institute in 2000 showed a dry bed. A more highly reflective bed is located to either side of the sticky spot in regions of faster flow of KIS including one location where bore holes showed water at the ice-bed interface. However, the brightest bed is located approximately 80~km upstream of the sticky spot, where ice velocities are still on the order of 120~m a-1. Here radar reflected power is up to 1.5 times higher than elsewhere in the trunk despite the ice being 40% deeper. From this pattern of bed reflectivity we hypothesize that conditions allowing for rapid flow still exist under most areas of KIS and that sticky spots, like the one studied here, have played a key role in the ice stream shut down. We have also produced a map of detailed bed topography and tracked internal reflection layers over the sticky spot. We are able to trace the evolution of folds in the radar internal stratigraphy in this region in both time and space

  10. Radar Imaging and Feature Extraction

    DTIC Science & Technology

    2007-11-02

    aperture radar (ISAR) autofocus and imaging, synthetic aperture radar (SAR) autofocus and motion compensation, superresolution SAR image formation... superresolution image formation, and two parametric methods, MCRELAX (Motion Compensation RELAX) and MCCLEAN (Motion Compensation CLEAN), for simultaneous target...Direction Estimation) together with WRELAX) algorithm is proposed for the superresolution time delay estimation.

  11. Millimeter radar improves target identification

    NASA Astrophysics Data System (ADS)

    McAulay, Alastair D.

    2011-06-01

    Recently developed millimeter wave radar has advantages for target identification over conventional microwave radar which typically use lower frequencies. We describe the pertinent features involved in the construction of the new millimeter wave radar, the pseudo-optical cavity source and the quasi-optical duplexer. The long wavelength relative to light allows the radar beam to penetrate through most weather because the wavelength is larger than the particle size for dust, drizzle rain, fog. Further the mm wave beam passes through an atmospheric transmission window that provides a dip in attenuation. The higher frequency than conventional radar provides higher Doppler frequencies, for example, than X-band radar. We show by simulation that small characteristic vibrations and slow turns of an aircraft become visible so that the Doppler signature improves identification. The higher frequency also reduces beam width, which increases transmit and receive antenna gains. For the same power the transmit beam extends to farther range and the increase in receive antenna gain increases signal to noise ratio for improved detection and identification. The narrower beam can also reduce clutter and reject other noise more readily. We show by simulation that the radar can be used at lower elevations over the sea than conventional radar.

  12. Radar Control Optimal Resource Allocation

    DTIC Science & Technology

    2015-07-13

    Dartmouth, Nova Scotia, Canada by the McMaster University Intelligent PIXel (IPIX) X-band Polarimetric Coherent Radar during the OHGR - Dartmouth...Distribution is unlimited Wind Direction N Figure 7: Radar data collection site at OHGR, Nova Scotia. Source:[15] to having a significant wave height of 0.7 m

  13. Reducing Spaceborne-Doppler-Radar Rainfall-Velocity Error

    NASA Technical Reports Server (NTRS)

    Tanelli, Simone; Im, Eastwood; Durden, Stephen L.

    2008-01-01

    A combined frequency-time (CFT) spectral moment estimation technique has been devised for calculating rainfall velocity from measurement data acquired by a nadir-looking spaceborne Doppler weather radar system. Prior spectral moment estimation techniques used for this purpose are based partly on the assumption that the radar resolution volume is uniformly filled with rainfall. The assumption is unrealistic in general but introduces negligible error in application to airborne radar systems. However, for spaceborne systems, the combination of this assumption and inhomogeneities in rainfall [denoted non-uniform beam filling (NUBF)] can result in velocity measurement errors of several meters per second. The present CFT spectral moment estimation technique includes coherent processing of a series of Doppler spectra generated in a standard manner from data over measurement volumes that are partially overlapping in the along-track direction. Performance simulation of this technique using high-resolution data from an airborne rain-mapping radar shows that a spaceborne Ku-band Doppler radar operating at signal-to-noise ratios greater than 10 dB can achieve root-mean-square accuracy between 0.5 and 0.6 m/s in vertical-velocity estimates.

  14. Unusual radar echoes from the Greenland ice sheet

    NASA Technical Reports Server (NTRS)

    Rignot, E. J.; Vanzyl, J. J.; Ostro, S. J.; Jezek, K. C.

    1993-01-01

    In June 1991, the NASA/Jet Propulsion Laboratory airborne synthetic-aperture radar (AIRSAR) instrument collected the first calibrated data set of multifrequency, polarimetric, radar observations of the Greenland ice sheet. At the time of the AIRSAR overflight, ground teams recorded the snow and firn (old snow) stratigraphy, grain size, density, and temperature at ice camps in three of the four snow zones identified by glaciologists to characterize four different degrees of summer melting of the Greenland ice sheet. The four snow zones are: (1) the dry-snow zone, at high elevation, where melting rarely occurs; (2) the percolation zone, where summer melting generates water that percolates down through the cold, porous, dry snow and then refreezes in place to form massive layers and pipes of solid ice; (3) the soaked-snow zone where melting saturates the snow with liquid water and forms standing lakes; and (4) the ablation zone, at the lowest elevations, where melting is vigorous enough to remove the seasonal snow cover and ablate the glacier ice. There is interest in mapping the spatial extent and temporal variability of these different snow zones repeatedly by using remote sensing techniques. The objectives of the 1991 experiment were to study changes in radar scattering properties across the different melting zones of the Greenland ice sheet, and relate the radar properties of the ice sheet to the snow and firn physical properties via relevant scattering mechanisms. Here, we present an analysis of the unusual radar echoes measured from the percolation zone.

  15. High-resolution instrumentation radar

    NASA Astrophysics Data System (ADS)

    Dybdal, Robert B.; Hurlbut, Keith H.; Mori, Tsutomu T.

    1986-09-01

    The development of an instrumentation radar that uses a chirp waveform to achieve high range resolution is described. Such range resolution capability is required for two reasons: (1) to evaluate the response of targets to the operational waveforms used in high-performance radars; and (2) to obtain a means of separating the individual mechanisms that comprise the target scattering response to better understand the scattering process. This particular radar was efficiently constructed from a combination of commercially available components and in-house-fabricated circuitry. This instrumentation radar operates at X-band and achieves a 4.9-in. range resolution. A key feature of the radar is its ability to combine amplitude weighting with a high degree of waveform fidelity, with the result being very good range sidelobe performance.

  16. Low-brightness quantum radar

    NASA Astrophysics Data System (ADS)

    Lanzagorta, Marco

    2015-05-01

    One of the major scientific thrusts from recent years has been to try to harness quantum phenomena to dramatically increase the performance of a wide variety of classical information processing devices. These advances in quantum information science have had a considerable impact on the development of standoff sensors such as quantum radar. In this paper we analyze the theoretical performance of low-brightness quantum radar that uses entangled photon states. We use the detection error probability as a measure of sensing performance and the interception error probability as a measure of stealthiness. We compare the performance of quantum radar against a coherent light sensor (such as lidar) and classical radar. In particular, we restrict our analysis to the performance of low-brightness standoff sensors operating in a noisy environment. We show that, compared to the two classical standoff sensing devices, quantum radar is stealthier, more resilient to jamming, and more accurate for the detection of low reflectivity targets.

  17. Radar SLAM using visual features

    NASA Astrophysics Data System (ADS)

    Callmer, Jonas; Törnqvist, David; Gustafsson, Fredrik; Svensson, Henrik; Carlbom, Pelle

    2011-12-01

    A vessel navigating in a critical environment such as an archipelago requires very accurate movement estimates. Intentional or unintentional jamming makes GPS unreliable as the only source of information and an additional independent supporting navigation system should be used. In this paper, we suggest estimating the vessel movements using a sequence of radar images from the preexisting body-fixed radar. Island landmarks in the radar scans are tracked between multiple scans using visual features. This provides information not only about the position of the vessel but also of its course and velocity. We present here a navigation framework that requires no additional hardware than the already existing naval radar sensor. Experiments show that visual radar features can be used to accurately estimate the vessel trajectory over an extensive data set.

  18. Development of High Altitude UAV Weather Radars for Hurricane Research

    NASA Technical Reports Server (NTRS)

    Heymsfield, Gerald; Li, Li-Hua

    2005-01-01

    precipitation, the surface return over a single 360 degree sweep over -25 h-diameter region provides information on the surface wind speed and direction within the scan circle. In precipitation regions, the conical scan with appropriate mapping and analysis provides the 3D structure of reflectivity beneath the plane and the horizontal winds. The use of conical scanning in hurricanes has recently been demonstrated for measuring inner core winds with the IWRAP system flying on the NOAA P3's. In this presentation, we provide a description of the URAD system hardware, status, and future plans. In addition to URAD, NASA SBIR activity is supporting a Phase I study by Remote Sensing Solutions and the University of Massachusetts for a dual-frequency IWRAP for a high altitude UAV that utilizes solid state transmitters at 14 and 35 GHz, the same frequencies that are planned for the radar on the Global Precipitation System satellite. This will be discussed elsewhere at the meeting.

  19. Integration of WERA Ocean Radar into Tsunami Early Warning Systems

    NASA Astrophysics Data System (ADS)

    Dzvonkovskaya, Anna; Helzel, Thomas; Kniephoff, Matthias; Petersen, Leif; Weber, Bernd

    2016-04-01

    High-frequency (HF) ocean radars give a unique capability to deliver simultaneous wide area measurements of ocean surface current fields and sea state parameters far beyond the horizon. The WERA® ocean radar system is a shore-based remote sensing system to monitor ocean surface in near real-time and at all-weather conditions up to 300 km offshore. Tsunami induced surface currents cause increasing orbital velocities comparing to normal oceanographic situation and affect the measured radar spectra. The theoretical approach about tsunami influence on radar spectra showed that a tsunami wave train generates a specific unusual pattern in the HF radar spectra. While the tsunami wave is approaching the beach, the surface current pattern changes slightly in deep water and significantly in the shelf area as it was shown in theoretical considerations and later proved during the 2011 Japan tsunami. These observed tsunami signatures showed that the velocity of tsunami currents depended on a tsunami wave height and bathymetry. The HF ocean radar doesn't measure the approaching wave height of a tsunami; however, it can resolve the surface current velocity signature, which is generated when tsunami reaches the shelf edge. This strong change of the surface current can be detected by a phased-array WERA system in real-time; thus the WERA ocean radar is a valuable tool to support Tsunami Early Warning Systems (TEWS). Based on real tsunami measurements, requirements for the integration of ocean radar systems into TEWS are already defined. The requirements include a high range resolution, a narrow beam directivity of phased-array antennas and an accelerated data update mode to provide a possibility of offshore tsunami detection in real-time. The developed software package allows reconstructing an ocean surface current map of the area observed by HF radar based on the radar power spectrum processing. This fact gives an opportunity to issue an automated tsunami identification message

  20. On Utilization of NEXRAD Scan Strategy Information to Infer Discrepancies Associated With Radar and Rain Gauge Surface Volumetric Rainfall Accumulations

    NASA Technical Reports Server (NTRS)

    Roy, Biswadev; Datta, Saswati; Jones, W. Linwood; Kasparis, Takis; Einaudi, Franco (Technical Monitor)

    2000-01-01

    To evaluate the Tropical Rainfall Measuring Mission (TRMM) monthly Ground Validation (GV) rain map, 42 quality controlled tipping bucket rain gauge data (1 minute interpolated rain rates) were utilized. We have compared the gauge data to the surface volumetric rainfall accumulation of NEXRAD reflectivity field, (converting to rain rates using a 0.5 dB resolution smooth Z-R table). The comparison was carried out from data collected at Melbourne, Florida during the month of July 98. GV operational level 3 (L3 monthly) accumulation algorithm was used to obtain surface volumetric accumulations for the radar. The gauge records were accumulated using the 1 minute interpolated rain rates while the radar Volume Scan (VOS) intervals remain less than or equal to 75 minutes. The correlation coefficient for the radar and gauge totals for the monthly time-scale remain at 0.93, however, a large difference was noted between the gauge and radar derived rain accumulation when the radar data interval is either 9 minute, or 10 minute. This difference in radar and gauge accumulation is being explained in terms of the radar scan strategy information. The discrepancy in terms of the Volume Coverage Pattern (VCP) of the NEXRAD is being reported where VCP mode is ascertained using the radar tilt angle information. Hourly radar and gauge accumulations have been computed using the present operational L3 method supplemented with a threshold period of +/- 5 minutes (based on a sensitivity analysis). These radar and gauge accumulations are subsequently improved using a radar hourly scan weighting factor (taking ratio of the radar scan frequency within a time bin to the 7436 total radar scans for the month). This GV procedure is further being improved by introducing a spatial smoothing method to yield reasonable bulk radar to gauge ratio for the hourly and daily scales.

  1. Propagation of radar rainfall uncertainty in urban flood simulations

    NASA Astrophysics Data System (ADS)

    Liguori, Sara; Rico-Ramirez, Miguel

    2013-04-01

    , 2010. Review of the different sources of uncertainty in single polarization radar-based estimates of rainfall. Surveys in Geophysics 31: 107-129. [4] Rossa A, Liechti K, Zappa M, Bruen M, Germann U, Haase G, Keil C, Krahe P, 2011. The COST 731 Action: A review on uncertainty propagation in advanced hydrometeorological forecast systems. Atmospheric Research 100, 150-167. [5] Rossa A, Bruen M, Germann U, Haase G, Keil C, Krahe P, Zappa M, 2010. Overview and Main Results on the interdisciplinary effort in flood forecasting COST 731-Propagation of Uncertainty in Advanced Meteo-Hydrological Forecast Systems. Proceedings of Sixth European Conference on Radar in Meteorology and Hydrology ERAD 2010. [6] Germann U, Berenguer M, Sempere-Torres D, Zappa M, 2009. REAL - ensemble radar precipitation estimation for hydrology in a mountainous region. Quarterly Journal of the Royal Meteorological Society 135: 445-456. [8] Bowler NEH, Pierce CE, Seed AW, 2006. STEPS: a probabilistic precipitation forecasting scheme which merges and extrapolation nowcast with downscaled NWP. Quarterly Journal of the Royal Meteorological Society 132: 2127-2155. [9] Zappa M, Rotach MW, Arpagaus M, Dorninger M, Hegg C, Montani A, Ranzi R, Ament F, Germann U, Grossi G et al., 2008. MAP D-PHASE: real-time demonstration of hydrological ensemble prediction systems. Atmospheric Science Letters 9, 80-87. [10] Liguori S, Rico-Ramirez MA. Quantitative assessment of short-term rainfall forecasts from radar nowcasts and MM5 forecasts. Hydrological Processes, accepted article. DOI: 10.1002/hyp.8415 [11] Liguori S, Rico-Ramirez MA, Schellart ANA, Saul AJ, 2012. Using probabilistic radar rainfall nowcasts and NWP forecasts for flow prediction in urban catchments. Atmospheric Research 103: 80-95. [12] Harrison DL, Driscoll SJ, Kitchen M, 2000. Improving precipitation estimates from weather radar using quality control and correction techniques. Meteorological Applications 7: 135-144. [13] Harrison DL, Scovell RW, Kitchen

  2. Mars Radar Observations with the Goldstone Solar System Radar

    NASA Technical Reports Server (NTRS)

    Haldemann, A. F. C.; Jurgens, R. F.; Larsen, K. W.; Arvidson, R. E.; Slade, M. A.

    2002-01-01

    The Goldstone Solar System Radar (GSSR) has successfully collected radar echo data from Mars over the past 30 years. As such, the GSSR has played a role as a specific mission element within Mars exploration. The older data provided local elevation information for Mars, along with radar scattering information with global resolution. Since the upgrade to the 70-m Deep Space Network (DSN) antenna at Goldstone completed in 1986, Mars data has been collected during all but the 1997 Mars opposition. Radar data, and non-imaging delay-Doppler data in particular, requires significant data processing to extract elevation, reflectivity and roughness of the reflecting surface. The spatial resolution of these experiments is typically some 20 km in longitude by some 150 km in latitude. The interpretation of these parameters while limited by the complexities of electromagnetic scattering, do provide information directly relevant to geophysical and geomorphic analyses of Mars. The usefulness of radar data for Mars exploration has been demonstrated in the past. Radar data were critical in assessing the Viking Lander 1 site as well as, more recently, the Pathfinder landing site. In general, radar data have not been available to the Mars exploration community at large. A project funded initially by the Mars Exploration Directorate Science Office at the Jet Propulsion Laboratory (JPL), and later funded by NASA's Mars Data Analysis Program has reprocessed to a common format a decade's worth of raw GSSR Mars delay-Doppler data in aid of landing site characterization for the Mars Program. These data will soon be submitted to the Planetary Data System (PDS). The radar data used were obtained between 1988 and 1995 by the GSSR, and comprise some 63 delay-Doppler radar tracks. Of these, 15 have yet to be recovered from old 9-track tapes, and some of the data may be permanently lost.

  3. Spectral measurements in support of SIR-B using the Surface Contour Radar. [for South Pacific

    NASA Technical Reports Server (NTRS)

    Walsh, E. J.; Hancock, D. W., III; Hines, D. E.; Swift, R. N.; Scott, J. F.

    1985-01-01

    The use of the Surface Contour Radar (SCR) from an aircraft to obtain spectral information on the seas off the tip of South America, in support of the SIR-B experiment in October 1984, is reported. The SCR is a computer-controlled 36-GHz radar that measures sea surface directional wave spectra and produces a real-time topographical map of the surface below the aircraft. Ground tracks and polar plots of the data obtained are illustrated.

  4. Obstacles facing the venus radar mapper - The implications of gestalt formation in stereo-radargrammetry

    USGS Publications Warehouse

    Wildey, R.L.

    1986-01-01

    The question of adapting to radar images the existing hardware that form topographic maps through stereo-photogrammetric models, is examined in principle. Such hardware utilizes a human/ computer hybrid. Although the problem of brightness differentials between corresponding landmarks can be dealt with pseudo-photoclinometrically, the main problem is whether the perspective in a radar image can be conceived to mimic that of a photographic image obtained by a suitably positioned camera. This conception is found to be possible, providing the characteristic relief subtends to a very small angle at the radar and at the fictitious camera. The photogrammetric model parameters must be determined a priori. ?? 1986 D. Reidel Publishing Company.

  5. Obstacles facing the Venus radar mapper - The implications of gestalt formation in stereo-radargrammetry

    USGS Publications Warehouse

    Wildey, R.L.

    1986-01-01

    The question of adapting to radar images the existing hardware that form topographic maps through stereo-photogrammetric models, is examined in principle. Such hardware utilizes a human/computer hybrid. Although the problem of brightness differentials between corresponding landmarks can be dealt with pseudo-photoclinometrically, the main problem is whether the perspective in a radar image can be conceived to mimic that of a photographic image obtained by a suitably positioned camera. This conception is found to be possible, providing the characteristic relief subtends a very small angle at the radar and at the fictitious camera. The photogrammetric model parameters must be determined a priori. ?? 1986 D. Reidel Publishing Company.

  6. 47 CFR 80.273 - Radar standards.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 47 Telecommunication 5 2013-10-01 2013-10-01 false Radar standards. 80.273 Section 80.273... MARITIME SERVICES Equipment Authorization for Compulsory Ships § 80.273 Radar standards. (a) Radar... with radar must comply with the following standards (all incorporated by reference, see § 80.7):...

  7. 47 CFR 80.273 - Radar standards.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 47 Telecommunication 5 2012-10-01 2012-10-01 false Radar standards. 80.273 Section 80.273... MARITIME SERVICES Equipment Authorization for Compulsory Ships § 80.273 Radar standards. (a) Radar... with radar must comply with the following standards (all incorporated by reference, see § 80.7):...

  8. FIRE_CI2_ETL_RADAR

    Atmospheric Science Data Center

    2015-11-25

    FIRE_CI2_ETL_RADAR Project Title:  FIRE II CIRRUS Discipline:  ... Platform:  Ground Station Instrument:  Radar Spatial Coverage:  (37.06, -95.34) Spatial ... Search Guide Documents:  ETL_RADAR Guide Readme Files:  Readme ETL_RADAR (PS) ...

  9. 47 CFR 80.273 - Radar standards.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 47 Telecommunication 5 2014-10-01 2014-10-01 false Radar standards. 80.273 Section 80.273... MARITIME SERVICES Equipment Authorization for Compulsory Ships § 80.273 Radar standards. (a) Radar... with radar must comply with the following standards (all incorporated by reference, see § 80.7):...

  10. RADAR OBSERVATION CONDITIONS OF POOR VISIBILITY,

    DTIC Science & Technology

    Ship navigational radar is an effective means for revealing above-water objects in conditions of poor visibility. A radar image of the surrounding...radar observation and with the competent operation of the set, radar is a reliable means of detection of encountered vessels in conditions of poor

  11. Radar, Insect Population Ecology, and Pest Management

    NASA Technical Reports Server (NTRS)

    Vaughn, C. R. (Editor); Wolf, W. (Editor); Klassen, W. (Editor)

    1979-01-01

    Discussions included: (1) the potential role of radar in insect ecology studies and pest management; (2) the potential role of radar in correlating atmospheric phenomena with insect movement; (3) the present and future radar systems; (4) program objectives required to adapt radar to insect ecology studies and pest management; and (5) the specific action items to achieve the objectives.

  12. Evaluation of meteorological airborne Doppler radar

    NASA Technical Reports Server (NTRS)

    Hildebrand, P. H.; Mueller, C. K.

    1984-01-01

    This paper will discuss the capabilities of airborne Doppler radar for atmospheric sciences research. The evaluation is based on airborne and ground based Doppler radar observations of convective storms. The capability of airborne Doppler radar to measure horizontal and vertical air motions is evaluated. Airborne Doppler radar is shown to be a viable tool for atmospheric sciences research.

  13. Combining Radar and Optical Data for Forest Disturbance Studies

    NASA Technical Reports Server (NTRS)

    Ranson, K. Jon; Smith, David E. (Technical Monitor)

    2002-01-01

    Disturbance is an important factor in determining the carbon balance and succession of forests. Until the early 1990's researchers have focused on using optical or thermal sensors to detect and map forest disturbances from wild fires, logging or insect outbreaks. As part of a NASA Siberian mapping project, a study evaluated the capability of three different radar sensors (ERS, JERS and Radarsat) and an optical sensor (Landsat 7) to detect fire scars, logging and insect damage in the boreal forest. This paper describes the data sets and techniques used to evaluate the use of remote sensing to detect disturbance in central Siberian forests. Using images from each sensor individually and combined an assessment of the utility of using these sensors was developed. Transformed Divergence analysis and maximum likelihood classification revealed that Landsat data was the single best data type for this purpose. However, the combined use of the three radar and optical sensors did improve the results of discriminating these disturbances.

  14. On the automatic classification of rain patterns on radar images

    NASA Astrophysics Data System (ADS)

    Pawlina Bonati, Apolonia

    The automation of the process of identification and classification of rain patterns on radar derived images is approached using some tools of digital image interpretation adapted to the specific application. The formal characterization of rain patterns and their partition in classes related to the type of precipitation is the main problem addressed in the paper, as the standard well established criteria for such classification are not defined. The digital maps of rain at horizontal plane derived from three-dimensional radar scans are processed by the interpretation package which identifies and classifies rain structures present on the map. The results generated by this package are illustrated in the paper and offered for discussion. The interpretation procedure is tailored for the radio-meteorology applications but the method is adaptable to other field requirements.

  15. Bird migration flight altitudes studied by a network of operational weather radars

    PubMed Central

    Dokter, Adriaan M.; Liechti, Felix; Stark, Herbert; Delobbe, Laurent; Tabary, Pierre; Holleman, Iwan

    2011-01-01

    A fully automated method for the detection and quantification of bird migration was developed for operational C-band weather radar, measuring bird density, speed and direction as a function of altitude. These weather radar bird observations have been validated with data from a high-accuracy dedicated bird radar, which was stationed in the measurement volume of weather radar sites in The Netherlands, Belgium and France for a full migration season during autumn 2007 and spring 2008. We show that weather radar can extract near real-time bird density altitude profiles that closely correspond to the density profiles measured by dedicated bird radar. Doppler weather radar can thus be used as a reliable sensor for quantifying bird densities aloft in an operational setting, which—when extended to multiple radars—enables the mapping and continuous monitoring of bird migration flyways. By applying the automated method to a network of weather radars, we observed how mesoscale variability in weather conditions structured the timing and altitude profile of bird migration within single nights. Bird density altitude profiles were observed that consisted of multiple layers, which could be explained from the distinct wind conditions at different take-off sites. Consistently lower bird densities are recorded in The Netherlands compared with sites in France and eastern Belgium, which reveals some of the spatial extent of the dominant Scandinavian flyway over continental Europe. PMID:20519212

  16. Application of Radar Data to Remote Sensing and Geographical Information Systems

    NASA Technical Reports Server (NTRS)

    vanZyl, Jakob J.

    2000-01-01

    The field of synthetic aperture radar changed dramatically over the past decade with the operational introduction of advance radar techniques such as polarimetry and interferometry. Radar polarimetry became an operational research tool with the introduction of the NASA/JPL AIRSAR system in the early 1980's, and reached a climax with the two SIR-C/X-SAR flights on board the space shuttle Endeavour in April and October 1994. Radar interferometry received a tremendous boost when the airborne TOPSAR system was introduced in 1991 by NASA/JPL, and further when data from the European Space Agency ERS-1 radar satellite became routinely available in 1991. Several airborne interferometric SAR systems are either currently operational, or are about to be introduced. Radar interferometry is a technique that allows one to map the topography of an area automatically under all weather conditions, day or night. The real power of radar interferometry is that the images and digital elevation models are automatically geometrically resampled, and could be imported into GIS systems directly after suitable reformatting. When combined with polarimetry, a technique that uses polarization diversity to gather more information about the geophysical properties of the terrain, a very rich multi-layer data set is available to the remote sensing scientist. This talk will discuss the principles of radar interferometry and polarimetry with specific application to the automatic categorization of land cover. Examples will include images acquired with the NASA/JPL AIRSAR/TOPSAR system in Australia and elsewhere.

  17. Radar image with color as height, Bahia State, Brazil

    NASA Technical Reports Server (NTRS)

    2000-01-01

    This radar image is the first to show the full 240-kilometer-wide (150 mile)swath collected by the Shuttle Radar Topography Mission (SRTM). The area shown is in the state of Bahia in Brazil. The semi-circular mountains along the leftside of the image are the Serra Da Jacobin, which rise to 1100 meters (3600 feet) above sea level. The total relief shown is approximately 800 meters (2600 feet). The top part of the image is the Sertao, a semi-arid region, that is subject to severe droughts during El Nino events. A small portion of the San Francisco River, the longest river (1609 kilometers or 1000 miles) entirely within Brazil, cuts across the upper right corner of the image. This river is a major source of water for irrigation and hydroelectric power. Mapping such regions will allow scientists to better understand the relationships between flooding cycles, drought and human influences on ecosystems.

    This image combines two types of data from the Shuttle Radar Topography Mission. The image brightness corresponds to the strength of the radar signal reflected from the ground, while colors show the elevation as measured by SRTM. The three dark vertical stripes show the boundaries where four segments of the swath are merged to form the full scanned swath. These will be removed in later processing. Colors range from green at the lowest elevations to reddish at the highest elevations.

    The Shuttle Radar Topography Mission (SRTM), launched on February 11, 2000, uses the same radar instrument that comprised the Spaceborne Imaging Radar-C/X-Band Synthetic Aperture Radar (SIR-C/X-SAR) that flew twice on the Space Shuttle Endeavour in 1994. The mission is designed to collect three-dimensional measurements of the Earth's surface. To collect the 3-D data, engineers added a 60-meter-long (200-foot) mast, an additional C-band imaging antenna and improved tracking and navigation devices. The mission is a cooperative project between the National Aeronautics and Space

  18. Output tube emission characteristics of operational radars

    NASA Astrophysics Data System (ADS)

    Matheson, R. J.; Smilley, J. D.; Falcon, G. D.; Lawrence, V. S.

    1982-01-01

    Measurement of the emission spectra and other characteristics of many radars operating in the government frequency bands is described. The emission spectra of 19 different types of radars, selected to show the different emission spectrum characteristics produced by a variety of radar output tube technologies are presented. The radars include examples of ground based search, airport surveillance, weather, and height finding radars operating in L band, S band, or C band. The RSMS, contained within a mobile van, is described, along with the measurement techniques used for obtaining radar emission characteristics. The emission limits imposed by the Radar Spectrum Engineering Criteria (RSEC) are displayed with each emission spectrum.

  19. Space Radar Image of Mammoth, California

    NASA Technical Reports Server (NTRS)

    1999-01-01

    These two images were created using data from the Spaceborne Imaging Radar C/X-Band Synthetic Aperture Radar (SIR-C/X-SAR). The image on the left is a false-color composite of the Mammoth Mountain area in California's Sierra Nevada Mountains centered at 37.6 degrees north, 119.0 degrees west. It was acquired on-board the space shuttle Endeavour on its 67th orbit on April 13, 1994. In the image on the left, red is C-band HV-polarization, green is C-band HH-polarization and blue is the ratio of C-band VV-polarization to C-band HV-polarization. On the right is a classification map of the surface features which was developed by SIR-C/X-SAR science team members at the University of California, Santa Barbara. The area is about 23 by 46 kilometers (14 by 29 miles). In the classification image, the colors represent the following surfaces: White snow Red frozen lake, covered by snow Brown bare ground Blue lake (open water) Yellow short vegetation (mainly brush) Green sparse forest Dark green dense forest Maps like this one are helpful to scientists studying snow wetness and snow water equivalent in the snow pack. Across the globe, over major portions of the middle and high latitudes, and at high elevations in the tropical latitudes, snow and alpine glaciers are the largest contributors to run-off in rivers and to ground-water recharge. Snow hydrologists are using radar in an attempt to estimate both the quantity of water held by seasonal snow packs and the timing of snow melt. Snow and ice also play important roles in regional climates; understanding the processes in seasonal snow cover is also important for studies of the chemical balance of alpine drainage basins. SIR-C/X-SAR is a powerful tool because it is sensitive to most snow pack conditions and is less influenced by weather conditions than other remote sensing instruments, such as the Landsat satellite. Spaceborne Imaging Radar-C and X-Synthetic Aperture Radar (SIR-C/X-SAR) is part of NASA's Mission to Planet Earth

  20. Geostatistical Methods For Determination of Roughness, Topography, And Changes of Antarctic Ice Streams From SAR And Radar Altimeter Data

    NASA Technical Reports Server (NTRS)

    Herzfeld, Ute C.

    2002-01-01

    The central objective of this project has been the development of geostatistical methods fro mapping elevation and ice surface characteristics from satellite radar altimeter (RA) and Syntheitc Aperture Radar (SAR) data. The main results are an Atlas of elevation maps of Antarctica, from GEOSAT RA data and an Atlas from ERS-1 RA data, including a total of about 200 maps with 3 km grid resolution. Maps and digital terrain models are applied to monitor and study changes in Antarctic ice streams and glaciers, including Lambert Glacier/Amery Ice Shelf, Mertz and Ninnis Glaciers, Jutulstraumen Glacier, Fimbul Ice Shelf, Slessor Glacier, Williamson Glacier and others.

  1. Space Radar Image of Houston, Texas

    NASA Technical Reports Server (NTRS)

    1994-01-01

    This image of Houston, Texas, shows the amount of detail that is possible to obtain using spaceborne radar imaging. Images such as this -- obtained by the Spaceborne Imaging Radar-C/X-band Synthetic Aperture Radar (SIR-C/X-SAR) flying aboard the space shuttle Endeavor last fall -- can become an effective tool for urban planners who map and monitor land use patterns in urban, agricultural and wetland areas. Central Houston appears pink and white in the upper portion of the image, outlined and crisscrossed by freeways. The image was obtained on October 10, 1994, during the space shuttle's 167th orbit. The area shown is 100 kilometers by 60 kilometers (62 miles by 38 miles) and is centered at 29.38 degrees north latitude, 95.1 degrees west longitude. North is toward the upper left. The pink areas designate urban development while the green-and blue-patterned areas are agricultural fields. Black areas are bodies of water, including Galveston Bay along the right edge and the Gulf of Mexico at the bottom of the image. Interstate 45 runs from top to bottom through the image. The narrow island at the bottom of the image is Galveston Island, with the city of Galveston at its northeast (right) end. The dark cross in the upper center of the image is Hobby Airport. Ellington Air Force Base is visible below Hobby on the other side of Interstate 45. Clear Lake is the dark body of water in the middle right of the image. The green square just north of Clear Lake is Johnson Space Center, home of Mission Control and the astronaut training facilities. The black rectangle with a white center that appears to the left of the city center is the Houston Astrodome. The colors in this image were obtained using the follow radar channels: red represents the L-band (horizontally transmitted, vertically received); green represents the C-band (horizontally transmitted, vertically received); blue represents the C-band (horizontally transmitted and received). Spaceborne Imaging Radar

  2. Space Radar Image of Kliuchevskoi, Russia

    NASA Technical Reports Server (NTRS)

    1994-01-01

    mature in Kamchatka's 120-day growing season. The forest industry is managing these forests and practicing selective cutting to allow younger trees time to grow and reseed. X-SAR images will aid in mapping these deforested areas and in encouraging further recultivation efforts. Spaceborne Imaging Radar-C and X-band Synthetic Aperture Radar (SIR-C/X-SAR) is part of NASA's Mission to Planet Earth. The radars illuminate Earth with microwaves, allowing detailed observations at any time, regardless of weather or sunlight conditions. SIR-C/X-SAR uses three microwave wavelengths: L-band (24 cm), C-band (6 cm) and X-band (3 cm). The multi-frequency data will be used by the international scientific community to better understand the global environment and how it is changing. The SIR-C/X-SAR data, complemented by aircraft and ground studies, will give scientists clearer insights into those environmental changes which are caused by nature and those changes which are induced by human activity. SIR-C was developed by NASA's Jet Propulsion Laboratory. X-SAR was developed by the Dornier and Alenia Spazio companies for the German space agency, Deutsche Agentur fuer Raumfahrtange-legenheiten (DARA), and the Italian space agency, Agenzia Spaziale Italiana (ASI), with the Deutsche Forschungsanstalt fuer Luft und Raumfahrt e.V.(DLR), the major partner in science, operations and data processing of X-SAR.

  3. The Apollo 17 Lunar Sounder. [lunar orbit coherent radar experiment

    NASA Technical Reports Server (NTRS)

    Phillips, R. J.; Brown, W. E., Jr.; Jordan, R.; Adams, G. F.; Jackson, P.; Peeples, W. J.; Porcello, L. J.; Ryu, J.; Eggleton, R. E.; Schaber, G.

    1973-01-01

    The Apollo Lunar Sounder Experiment, a coherent radar operated from lunar orbit during the Apollo 17 mission, has scientific objectives of mapping lunar subsurface structure, surface profiling, surface imaging, and galactic noise measurement. Representative results from each of the four disciplines are presented. Subsurface reflections have been interpreted in both optically and digitally processed data. Images and profiles yield detailed selenomorphological information. The preliminary galactic noise results are consistent with earlier measurements by other workers.

  4. Mapping products of Titan's surface

    USGS Publications Warehouse

    Stephan, Katrin; Jaumann, Ralf; Karkoschka, Erich; Barnes, Jason W.; Tomasko, Martin G.; Turtle, Elizabeth P.; Le Corre, Lucille; Langhans, Mirjam; Le Mouelic, Stephane; Lorenz, Ralf D.; Perry, Jason; Brown, Robert H.; Lebreton, Jean-Pierre

    2009-01-01

    Remote sensing instruments aboard the Cassini spacecraft have been observed the surface of Titan globally in the infrared and radar wavelength ranges as well as locally by the Huygens instruments revealing a wealth of new morphological features indicating a geologically active surface. We present a summary of mapping products of Titan's surface derived from data of the remote sensing instruments onboard the Cassini spacecraft (ISS, VIMS, RADAR) as well as the Huygens probe (DISR) that were achieved during the nominal Cassini mission including an overview of Titan's recent nomenclature.

  5. The Clementine bistatic radar experiment.

    PubMed

    Nozette, S; Lichtenberg, C L; Spudis, P; Bonner, R; Ort, W; Malaret, E; Robinson, M; Shoemaker, E M

    1996-11-29

    During the Clementine 1 mission, a bistatic radar experiment measured the magnitude and polarization of the radar echo versus bistatic angle, beta, for selected lunar areas. Observations of the lunar south pole yield a same-sense polarization enhancement around beta = 0. Analysis shows that the observed enhancement is localized to the permanently shadowed regions of the lunar south pole. Radar observations of periodically solar-illuminated lunar surfaces, including the north pole, yielded no such enhancement. A probable explanation for these differences is the presence of low-loss volume scatterers, such as water ice, in the permanently shadowed region at the south pole.

  6. Gyroklystron-Powered WARLOC Radar

    NASA Astrophysics Data System (ADS)

    Danly, B. G.; Cheung, W. J.; Gregers-Hansen, V.; Linde, G.; Ngo, M.

    2003-12-01

    A high-power, coherent, W-band (94 GHz) millimeter-wave radar has been developed at the Naval Research Laboratory. This radar, named WARLOC, employs a 100 kW peak power, 10 kW average power gyro-klystron as the final power amplifier, an overmoded transmission line system, and a quasi-optical duplexer, together with a high gain antenna, four-channel receiver, and state-of-the-art signal processing. The gyro-amplifiers and the implementation in the WARLOC radar will be described.

  7. The Clementine Bistatic Radar Experiment

    NASA Technical Reports Server (NTRS)

    Nozette, S.; Lichtenberg, C. L.; Spudis, P.; Bonner, R.; Ort, W.; Malaret, E.; Robinson, M.; Shoemaker, E. M.

    1996-01-01

    During the Clementine 1 mission, a bistatic radar experiment measured the magnitude and polarization of the radar echo versus bistatic angle, beta, for selected lunar areas. Observations of the lunar south pole yield a same-sense polarization enhancement around beta = 0. Analysis shows that the observed enhancement is localized to the permanently shadowed regions of the lunar south pole. Radar observations of periodically solar-illuminated lunar surfaces, including the north pole, yielded no such enhancement. A probable explanation for these differences is the presence of low-loss volume scatterers, such as water ice, in the permanently shadowed region at the south pole.

  8. The Clementine bistatic radar experiment

    USGS Publications Warehouse

    Nozette, S.; Lichtenberg, C.L.; Spudis, P.; Bonner, R.; Ort, W.; Malaret, E.; Robinson, M.; Shoemaker, E.M.

    1996-01-01

    During the Clementine 1 mission, a bistatic radar experiment measured the magnitude and polarization of the radar echo versus bistatic angle, ??, for selected lunar areas. Observations of the lunar south pole yield a same- sense polarization enhancement around ?? = 0. Analysis shows that the observed enhancement is localized to the permanently shadowed regions of the lunar south pole. Radar observations of periodically solar-illuminated lunar surfaces, including the north pole, yielded no such enhancement. A probable explanation for these differences is the presence of low-loss volume scatterers, such as water ice, in the permanently shadowed region at the south pole.

  9. Radar investigation of asteroids

    NASA Technical Reports Server (NTRS)

    Ostro, S. J.

    1982-01-01

    The dual polarization CW radar system which permits simultaneous reception in the same rotational sense of circular polarization as transmitted (i.e., the "SC" sense) and in the opposite ("OC") sense, was used to observe five previously unobserved asteroids: 2 Pallas, 8 Flora, 22 Kalliope, 132 Aethra, and 471 Papagena. Echoes from Pallas and Flora were easily detected in the OC sense on each of several nights. Weighted mean echo power spectra also show marginally significant responses in the SC sense. An approximately 4.5 standard deviation signal was obtained for Aethra. The Doppler shift of the peak is about 10 Hz higher than that predicted from the a priori trial ephemeris. Calculations are performed to determine whether this frequency offset can be reconciled dynamically with optical positions reported for Aethra.

  10. Radar investigation of asteroids

    NASA Astrophysics Data System (ADS)

    Ostro, S. J.

    1981-07-01

    Radar investigations were conducted of selected minor planets, including: (1) observations during 1981-82 of 10 potential targets (2 Pallas, 8 Flora, 12 Victoria, 15 Eunomia, 19 Fortuna, 22 Kalliope, 132 Aethra, 219 Thusnelda, 433 Eros, and 2100 Ra-Shalom); and (2) continued analyses of observational data obtained during 1980-81 for 10 other asteroids (4 Vesta, 7 Iris, 16 Psyche, 75 Eurydike, 97 Klotho, 216 Kleopatra, 1685 Toro, 1862 Apollo, 1865 Cerberus, and 1915 Quetzalcoatl). Scientific objectives include estimation of echo strength, polarization, spectral shape, spectral bandwidth, and Doppler shift. These measurements: (1) yield estimates of target size, shape, and spin vector; (2) place constraints on topography, morphology, and composition of the planetary surface; (3) yield refined estimates of target orbital parameters; (4) reveal the presence of asteroidal satellites.

  11. Imaging Radar in the Mojave Desert-Death Valley Region

    NASA Technical Reports Server (NTRS)

    Farr, Tom G.

    2001-01-01

    The Mojave Desert-Death Valley region has had a long history as a test bed for remote sensing techniques. Along with visible-near infrared and thermal IR sensors, imaging radars have flown and orbited over the area since the 1970's, yielding new insights into the geologic applications of these technologies. More recently, radar interferometry has been used to derive digital topographic maps of the area, supplementing the USGS 7.5' digital quadrangles currently available for nearly the entire area. As for their shorter-wavelength brethren, imaging radars were tested early in their civilian history in the Mojave Desert-Death Valley region because it contains a variety of surface types in a small area without the confounding effects of vegetation. The earliest imaging radars to be flown over the region included military tests of short-wavelength (3 cm) X-band sensors. Later, the Jet Propulsion Laboratory began its development of imaging radars with an airborne sensor, followed by the Seasat orbital radar in 1978. These systems were L-band (25 cm). Following Seasat, JPL embarked upon a series of Space Shuttle Imaging Radars: SIRA (1981), SIR-B (1984), and SIR-C (1994). The most recent in the series was the most capable radar sensor flown in space and acquired large numbers of data swaths in a variety of test areas around the world. The Mojave Desert-Death Valley region was one of those test areas, and was covered very well with 3 wavelengths, multiple polarizations, and at multiple angles. At the same time, the JPL aircraft radar program continued improving and collecting data over the Mojave Desert Death Valley region. Now called AIRSAR, the system includes 3 bands (P-band, 67 cm; L-band, 25 cm; C-band, 5 cm). Each band can collect all possible polarizations in a mode called polarimetry. In addition, AIRSAR can be operated in the TOPSAR mode wherein 2 antennas collect data interferometrically, yielding a digital elevation model (DEM). Both L-band and C-band can be

  12. Studies on Radar and Non-radar Sensor Networks

    DTIC Science & Technology

    2006-06-15

    selection based on specific applications. References [1] Q . Liang, "Waveform Design and Diversity in Radar Sensor Networks: Theoretical Analysis and...Application to Automatic Target Recognition," submitted to IEEE Trans on Aerospace and Electronic Systems. [2] Q . Liang, "Waveform Design and Diversity in...Sensor Networks, June 2006, New York. [3] Q . Liang, "Radar Sensor Networks: Algorithms for Waveform Design and Diversity with Appli- cation to ATR with

  13. Historical aspects of radar atmospheric dynamics

    NASA Technical Reports Server (NTRS)

    Kato, Susumu

    1989-01-01

    A review of the history of radar techniques which have been applied to atmospheric observation is given. The author starts with ionosphere observation with the ionosonde, symbolizing as it does the earliest history of radar observation, and proceeds to later developments in radar observation such as the use of partial reflection, meteor, and incoherent scatter radars. Mesosphere stratosphere troposphere (MST) radars are discussed in terms of lower atmosphere observation.

  14. C-Band Radar Imagery, Dallas-Fort Worth, Texas

    NASA Technical Reports Server (NTRS)

    2000-01-01

    The Dallas-Fort Worth metropolitan area in Texas is shown on this image collected by the C-band radar of the Shuttle Radar Topography Mission (SRTM). On this radar image, smooth areas, such as lakes, roads and airport runways appear dark. Rougher features, such as buildings and trees, appear bright. Downtown Dallas is the bright area at the center of the image, alongside the dark linear floodway of the Trinity River. Dark linear runways of two airports are also seen: Love Field near downtown Dallas in the image center, and Dallas-Fort Worth International Airport in the upper left corner. The semi-circular terminal buildings of the international airport can also be seen in the area between the runways. Several large lakes, including Lake Ray Hubbard (upper right) and Joe Pool Lake (lower left) are also seen. Images like these, along with the SRTM topographic data, will be used by urban planners to study and monitor land use, and update maps and geographic information systems for the area. This image represents just 4 seconds of data collection time by the SRTM instrument. The overall diagonal linear pattern is a data processing artifact due to the quick turn-around browse nature of this image. These artifacts will be removed with further data processing.

    This radar image was obtained by the Shuttle Radar Topography Mission as part of its mission to map the Earth's topography. The image was acquired by just one of SRTM's two antennas, and consequently does not show topographic data but only the strength of the radar signal reflected from the ground. This signal, known as radar backscatter, provides insight into the nature of the surface, including its roughness, vegetation cover, and urbanization.

    This image was acquired by the Shuttle Radar Topography Mission (SRTM) aboard the Space Shuttle Endeavour, launched on February 11, 2000. SRTM uses the same radar instrument that comprised the Spaceborne Imaging Radar-C/X-Band Synthetic Aperture Radar (SIR

  15. Fly eye radar or micro-radar sensor technology

    NASA Astrophysics Data System (ADS)

    Molchanov, Pavlo; Asmolova, Olga

    2014-05-01

    To compensate for its eye's inability to point its eye at a target, the fly's eye consists of multiple angularly spaced sensors giving the fly the wide-area visual coverage it needs to detect and avoid the threats around him. Based on a similar concept a revolutionary new micro-radar sensor technology is proposed for detecting and tracking ground and/or airborne low profile low altitude targets in harsh urban environments. Distributed along a border or around a protected object (military facility and buildings, camp, stadium) small size, low power unattended radar sensors can be used for target detection and tracking, threat warning, pre-shot sniper protection and provides effective support for homeland security. In addition it can provide 3D recognition and targets classification due to its use of five orders more pulses than any scanning radar to each space point, by using few points of view, diversity signals and intelligent processing. The application of an array of directional antennas eliminates the need for a mechanical scanning antenna or phase processor. It radically decreases radar size and increases bearing accuracy several folds. The proposed micro-radar sensors can be easy connected to one or several operators by point-to-point invisible protected communication. The directional antennas have higher gain, can be multi-frequency and connected to a multi-functional network. Fly eye micro-radars are inexpensive, can be expendable and will reduce cost of defense.

  16. Space Radar Image of Yellowstone Park, Wyoming

    NASA Technical Reports Server (NTRS)

    1994-01-01

    These two radar images show the majestic Yellowstone National Park, Wyoming, the oldest national park in the United States and home to the world's most spectacular geysers and hot springs. The region supports large populations of grizzly bears, elk and bison. In 1988, the park was burned by one of the most widespread fires to occur in the northern Rocky Mountains in the last 50 years. Surveys indicated that 793,880 acres of land burned. Of that, 41 percent was burned forest, with tree canopies totally consumed by the fire; 35 percent was a combination of unburned, scorched and blackened trees; 13 percent was surface burn under an unburned canopy; 6 percent was non-forest burn; and 5 percent was undifferentiated burn. Six years later, the burned areas are still clearly visible in these false-color radar images obtained by the Spaceborne Imaging Radar-C/X-band Synthetic Aperture Radar on board the space shuttle Endeavour. The image at the left was obtained using the L-band radar channel, horizontally received and vertically transmitted, on the shuttle's 39th orbit on October 2, 1994. The area shown is 45 kilometers by 71 kilometers (28 miles by 44 miles) in size and centered at 44.6 degrees north latitude, 110.7 degrees west longitude. North is toward the top of the image (to the right). Most trees in this area are lodge pole pines at different stages of fire succession. Yellowstone Lake appears as a large dark feature at the bottom of the scene. At right is a map of the forest crown, showing its biomass, or amount of vegetation, which includes foliage and branches. The map was created by inverting SIR-C data and using in situ estimates of crown biomass gathered by the Yellowstone National Biological Survey. The map is displayed on a color scale from blue (rivers and lakes with no biomass) to brown (non-forest areas with crown biomass of less than 4 tons per hectare) to light brown (areas of canopy burn with biomass of between 4 and 12 tons per hectare). Yellow

  17. Space Radar Image of Yellowstone Park, Wyoming

    NASA Technical Reports Server (NTRS)

    1994-01-01

    These two radar images show the majestic Yellowstone National Park, Wyoming, the oldest national park in the United States and home to the world's most spectacular geysers and hot springs. The region supports large populations of grizzly bears, elk and bison. In 1988, the park was burned by one of the most widespread fires to occur in the northern Rocky Mountains in the last 50 years. Surveys indicated that 793,880 acres of land burned. Of that, 41 percent was burned forest, with tree canopies totally consumed by the fire; 35 percent was a combination of unburned, scorched and blackened trees; 13 percent was surface burn under an unburned canopy; 6 percent was non-forest burn; and 5 percent was undifferentiated burn. Six years later, the burned areas are still clearly visible in these false-color radar images obtained by the Spaceborne Imaging Radar-C/X-band Synthetic Aperture Radar on board the space shuttle Endeavour. The image at the left was obtained using the L-band radar channel, horizontally received and vertically transmitted, on the shuttle's 39th orbit on October 2, 1994. The area shown is 45 kilometers by 71 kilometers (28 miles by 44 miles) in size and centered at 44.6 degrees north latitude, 110.7 degrees west longitude. North is toward the top of the image (to the right). Most trees in this area are lodge pole pines at different stages of fire succession. Yellowstone Lake appears as a large dark feature at the bottom of the scene. At right is a map of the forest crown, showing its biomass, or amount of vegetation, which includes foliage and branches. The map was created by inverting SIR-C data and using in situ estimates of crown biomass gathered by the Yellowstone National Biological Survey. The map is displayed on a color scale from blue (rivers and lakes with no biomass) to brown (non-forest areas with crown biomass of less than 4 tons per hectare) to light brown (areas of canopy burn with biomass of between 4 and 12 tons per hectare). Yellow

  18. Synthetic aperture radar processing with tiered subapertures

    SciTech Connect

    Doerry, A.W.

    1994-06-01

    Synthetic Aperture Radar (SAR) is used to form images that are maps of radar reflectivity of some scene of interest, from range soundings taken over some spatial aperture. Additionally, the range soundings are typically synthesized from a sampled frequency aperture. Efficient processing of the collected data necessitates using efficient digital signal processing techniques such as vector multiplies and fast implementations of the Discrete Fourier Transform. Inherent in image formation algorithms that use these is a trade-off between the size of the scene that can be acceptably imaged, and the resolution with which the image can be made. These limits arise from migration errors and spatially variant phase errors, and different algorithms mitigate these to varying degrees. Two fairly successful algorithms for airborne SARs are Polar Format processing, and Overlapped Subaperture (OSA) processing. This report introduces and summarizes the analysis of generalized Tiered Subaperture (TSA) techniques that are a superset of both Polar Format processing and OSA processing. It is shown how tiers of subapertures in both azimuth and range can effectively mitigate both migration errors and spatially variant phase errors to allow virtually arbitrary scene sizes, even in a dynamic motion environment.

  19. Ground Penetrating Radar, Barrow, Alaska

    DOE Data Explorer

    John Peterson

    2015-03-06

    This is 500 MHz Ground Penetrating Radar collected along the AB Line in Intensive Site 1 beginning in October 2012 and collected along L2 in Intensive Site 0 beginning in September 2011. Both continue to the present.

  20. NASA Radar Images Asteroid Toutatis

    NASA Video Gallery

    This 64-frame movie of asteroid Toutatis was generated from data by Goldstone's Solar System Radar on Dec. 12 and 13, 2012. In the movie clips, the rotation of the asteroid appears faster than it o...

  1. The megageomorphology of the radar rivers of the eastern Sahara

    NASA Technical Reports Server (NTRS)

    Mccauley, John F.; Breed, Carol S.; Schaber, Gerald G.

    1986-01-01

    The Eastern Sahara is devoid of surface drainage; this unusual characteristic distinguishes its morphology from that of most other desert regions where running water dominates landscape development. A map derived from SIR-A/B and LANDSAT images and the literature, shows the major presently known paleodrainages in the Eastern Sahara. This compilation permits consideration of the key questions: Where did the radar rivers come from and where did they go? Analysis of SIR-A data led McCauley et al. to suggest that the radar rivers, because of their southwestward trends, once flowed into the Chad basin. This key North African feature is a regional structural low formed in the Early Cretaceous in response to initial opening of the South Atlantic. The problem of the origin of headwaters for the radar rivers was less tractable. The idea that the source areas of the radar rivers might originally have been the same as those later captured by the Nile was proposed tentatively. A more extensive review of the Cenozoic tectonic history of North Africa reveals no reason now to suppose that the Central African tributaries of the present Nile were ever connected to the large alluvial valleys in southwestern Egypt and northwestern Sudan. formed in the Early Cretaceous in response to initial opening of the South Atlantic. The problem of the origin of headwaters for the radar rivers was less tractable. The idea that the source areas of the radar rivers might originally have been the same as those (The Ethiopian Highlands) later captured by the Nile was proposed tentatively. A more extensive review of the Cenozoic tectonic history of North Africa reveals no reason now to support that the Central African tributaries of the present Nile were ever connected to the large alluvial valleys in southwestern Egypt and northwestern Sudan.

  2. Advanced Borehole Radar for Hydrogeology

    NASA Astrophysics Data System (ADS)

    Sato, M.

    2014-12-01

    Ground Penetrating Radar is a useful tool for monitoring the hydrogeological environment. We have developed GPR systems which can be applied to these purposes, and we will demonstrate examples borehole radar measurements. In order to have longer radar detection range, frequency lower than100MHz has been normally adopted in borehole radar. Typical subsurface fractures of our interests have a few mm aperture and radar resolution is much poorer than a few cm in this frequency range. We are proposing and demonstrating to use radar polarimetry to solve this problem. We have demonstrated that a full-polarimetry borehole radar can be used for characterization of subsurface fractures. Together with signal processing for antenna characteristic compensation to equalize the signal by a dipole antenna and slot antennas, we could demonstrate that polarimetric borehole radar can estimate the surface roughness of subsurface fractures, We believe the surface roughness is closely related to water permeability through the fractures. We then developed a directional borehole radar, which uses optical field sensor. A dipole antenna in a borehole has omni-directional radiation pattern, and we cannot get azimuthal information about the scatterers. We use multiple dipole antennas set around the borehole axis, and from the phase differences, we can estimate the 3-diemnational orientation of subsurface structures. We are using optical electric field sensor for receiver of borehole radar. This is a passive sensor and connected only with optical fibers and does not require any electric power supply to operate the receiver. It has two major advantages; the first one is that the receiver can be electrically isolated from other parts, and wave coupling to a logging cable is avoided. Then, secondary, it can operate for a long time, because it does not require battery installed inside the system. It makes it possible to set sensors in fixed positions to monitor the change of environmental

  3. Solar Radar Astronomy with LOFAR

    NASA Astrophysics Data System (ADS)

    Rodriguez, P.

    2003-04-01

    A new approach to the study of the Sun's corona and its dynamical processes is possible with radar investigations in the frequency range of about 10-50 MHz. The range of electron densities of the solar corona is such that radio waves at these frequencies can provide diagnostic radar echoes of large scale phenomena such as coronal mass ejections (CMEs). We expect that the frequency shift imposed on the echo signal by an earthward-moving CME will provide a direct measurement of the velocity, thereby providing a good estimate of the arrival time at Earth. It is known that CMEs are responsible for the largest geomagnetic storms at Earth, which are capable of causing power grid blackouts, satellite electronic upsets, and degradation of radio communications circuits. Thus, having accurate forecasts of potential CME-initiated geomagnetic storms is of practical space weather interest. New high power transmitting arrays are becoming available, along with proposed modifications to existing research facilities, that will allow the use of radio waves to study the solar corona by the radar echo technique. Of particular interest for such solar radar investigations is the bistatic configuration with the Low Frequency Array (LOFAR). The LOFAR facility will have an effective receiving area of about 1 square km at solar radar frequencies. Such large effective area will provide the receiving antenna gain needed for detailed investigations of solar coronal dynamics. Conservative estimates of the signal-to-noise ratio for solar radar echoes as a function of the integration time required to achieve a specified detection level (e.g., ~ 5 dB) indicate that time resolutions of 10s of seconds can be achieved. Thus, we are able to resolve variations in the solar radar cross section on time scales which will provide new information on the plasma dynamical processes associated with the solar corona, such as CMEs. It is the combination of high transmitted power and large effective receiving

  4. The NASA Polarimetric Radar (NPOL)

    NASA Technical Reports Server (NTRS)

    Petersen, Walter A.; Wolff, David B.

    2013-01-01

    Characteristics of the NASA NPOL S-band dual-polarimetric radar are presented including its operating characteristics, field configuration, scanning capabilities and calibration approaches. Examples of precipitation science data collections conducted using various scan types, and associated products, are presented for different convective system types and previous field campaign deployments. Finally, the NASA NPOL radar location is depicted in its home base configuration within the greater Wallops Flight Facility precipitation research array supporting NASA Global Precipitation Measurement Mission ground validation.

  5. Radar Imaging and Target Identification

    DTIC Science & Technology

    2009-02-09

    Methods in Wave Propagation, Vaxjo, Swe- den. • February 19, 2008, "Radar Imaging", math colloquium, Brigham- Young University. • January 31, 2008...manuscript, namely "Radar detection using sparsely distributed 19 apertures in urban environments", Ling Wang, II- Young Son, Trond Varslot, C. Evren...Coinmun. COM- 20, pp. 774-780, 1972. [24] M. Tomlinson, "New automatic equalizer employing modulo arithmetic," Electron. Lett. 7, pp. 138-139, 1971

  6. Synthetic Aperture Radar Simulation Study

    DTIC Science & Technology

    1984-03-01

    multilook are discussed. A chapter is devoted to elevation and planimetric data bases. In addition, six- teen pictures of SAR images from Hughes Aircraft, as...scans. Figure 5.4-1 is a photograph ot two SAR displays. The tirst display is made up ot six subscans and has a multilook ot one. Note that tading is...dentfi by block number) * Synthetic Aperture Radar ( SAR ) Simulation Study Radar Simulation Data Bases 5/~t. 4th.- Computer Image Generation Display 20

  7. Representing radar QPE and QPF uncertainties using radar ensembles

    NASA Astrophysics Data System (ADS)

    Sempere-Torres, D.; Llort, X.; Roca, J.; Pegram, G.

    2009-09-01

    In the last years, new comprehension of the physics underlying the radar measurements as well as new technological advancements have allowed radar community to propose better algorithms and methodologies and significant advancements have been achieved in improving Quantitative Precipitation Estimates (QPE) and Quantitative Precipitation forecasting (QPF) by radar. Thus the study of the 2D uncertainties field associated to these estimates has become an important subject, specially to enhance the use of radar QPE and QPF in hydrological studies, as well as in providing a reference for satellite precipitations measurements. In this context the use of radar-based rainfall ensembles (i.e. equiprobable rainfall field scenarios generated to be compatible with the observations/forecasts and with the inferred structure of the uncertainties) has been seen as an extremely interesting tool to represent their associated uncertainties. The generation of such radar ensembles requires first the full characterization of the 3D field of associated uncertainties (2D spatial plus temporal), since rainfall estimates show an error structure highly correlated in space and time. A full methodology to deal with this kind of radar-based rainfall ensembles is presented. Given a rainfall event, the 2D uncertainty fields associated to the radar estimates are defined for every time step using a benchmark, or reference field, based on the best available estimate of the rainfall field. This benchmark is built using an advanced non parametric interpolation of a dense raingauge network able to use the spatial structure provided by the radar observations, and is confined to the region in which this combination could be taken as a reference measurement (Velasco-Forero et al. 2008, doi:10.1016/j.advwatres.2008.10.004). Then the spatial and temporal structures of these uncertainty fields are characterized and a methodology to generate consistent multiple realisations of them is used to generate the

  8. EISCAT Incoherent Scatter Radars Probing High-Latitude Near-Earth Geospace for the EURIPOS Proposal

    NASA Astrophysics Data System (ADS)

    Turunen, E.

    2009-04-01

    EISCAT Scientific Association operates currently three incoherent scatter radars in Northern Scandinavia on behalf of its associate members in Finland, China, Germany, Japan, Norway, Sweden and United Kingdom, as well as currently supporting partners in France and Russia. The radar sites include transmitter/receiver site in Tromsø, Norway with a monostatic VHF radar and a tristatic UHF radar transmitter/receiver, UHF receiver sites in Kiruna, Sweden and Sodankylä, Finland and a 2-dish monostatic radar in Longyearbyen, Svalbard. Incoherent scatter radar method is known to be the most sophisticated radio method to remotely sense the ionosphere. The standard parameters analysed from the recorded scattered signals are the electron density, electron temperature, ion temperature, line-of-sight plasma velocity, ion-neutral collision frequency and ion mass. With more assumptions also information for example on neutral density and temperature, neutral velocity, Pedersen and Hall conductivities, electric current density and heat flux is available. Current applications of the radars include also interferometric applications for small-scale structures, mapping of meteroid orbits and monitoring space debris, as well as high-resolution mapping the radar reflectivity of the Moon surface. In addition to incoherent scatter radars, EISCAT also has a powerful HF heating facility for ionospheric modification experiments, and a dynasonde in Tromsø, as well as another dynasonde in Svalbard for routine ionospheric observations. All the current EISCAT facilities would serve the EURIPOS proposal quantifying the ionospheric variability and response to space weather events at high latitudes. Although the main ISR facilities cannot be run continuously, regular Common Programmes, measurement campaign modes - especially combined with coordinated satellite observations and specific model studies, and the continuous operation of supporting dynasondes, would greatly enhance the EURIPOS proposal

  9. Hydrologic applications of weather radar

    NASA Astrophysics Data System (ADS)

    Seo, Dong-Jun; Habib, Emad; Andrieu, Hervé; Morin, Efrat

    2015-12-01

    By providing high-resolution quantitative precipitation information (QPI), weather radars have revolutionized hydrology in the last two decades. With the aid of GIS technology, radar-based quantitative precipitation estimates (QPE) have enabled routine high-resolution hydrologic modeling in many parts of the world. Given the ever-increasing need for higher-resolution hydrologic and water resources information for a wide range of applications, one may expect that the use of weather radar will only grow. Despite the tremendous progress, a number of significant scientific, technological and engineering challenges remain to realize its potential. New challenges are also emerging as new areas of applications are discovered, explored and pursued. The purpose of this special issue is to provide the readership with some of the latest advances, lessons learned, experiences gained, and science issues and challenges related to hydrologic applications of weather radar. The special issue features 20 contributions on various topics which reflect the increasing diversity as well as the areas of focus in radar hydrology today. The contributions may be grouped as follows: Radar QPE (Kwon et al.; Hall et al.; Chen and Chandrasekar; Seo and Krajewski; Sandford).

  10. Coded continuous wave meteor radar

    NASA Astrophysics Data System (ADS)

    Vierinen, Juha; Chau, Jorge L.; Pfeffer, Nico; Clahsen, Matthias; Stober, Gunter

    2016-03-01

    The concept of a coded continuous wave specular meteor radar (SMR) is described. The radar uses a continuously transmitted pseudorandom phase-modulated waveform, which has several advantages compared to conventional pulsed SMRs. The coding avoids range and Doppler aliasing, which are in some cases problematic with pulsed radars. Continuous transmissions maximize pulse compression gain, allowing operation at lower peak power than a pulsed system. With continuous coding, the temporal and spectral resolution are not dependent on the transmit waveform and they can be fairly flexibly changed after performing a measurement. The low signal-to-noise ratio before pulse compression, combined with independent pseudorandom transmit waveforms, allows multiple geographically separated transmitters to be used in the same frequency band simultaneously without significantly interfering with each other. Because the same frequency band can be used by multiple transmitters, the same interferometric receiver antennas can be used to receive multiple transmitters at the same time. The principles of the signal processing are discussed, in addition to discussion of several practical ways to increase computation speed, and how to optimally detect meteor echoes. Measurements from a campaign performed with a coded continuous wave SMR are shown and compared with two standard pulsed SMR measurements. The type of meteor radar described in this paper would be suited for use in a large-scale multi-static network of meteor radar transmitters and receivers. Such a system would be useful for increasing the number of meteor detections to obtain improved meteor radar data products.

  11. TRMM Precipitation Radar Reflectivity Profiles Compared to High-Resolution Airborne and Ground-Based Radar Measurements

    NASA Technical Reports Server (NTRS)

    Heymsfield, G. M.; Geerts, B.; Tian, L.

    1999-01-01

    In this paper, TRMM (Tropical Rainfall Measuring Mission Satellite) Precipitation Radar (PR) products are evaluated by means of simultaneous comparisons with data from the high-altitude ER-2 Doppler Radar (EDOP), as well as ground-based radars. The comparison is aimed primarily at the vertical reflectivity structure, which is of key importance in TRMM rain type classification and latent heating estimation. The radars used in this study have considerably different viewing geometries and resolutions, demanding non-trivial mapping procedures in common earth-relative coordinates. Mapped vertical cross sections and mean profiles of reflectivity from the PR, EDOP, and ground-based radars are compared for six cases. These cases cover a stratiform frontal rainband, convective cells of various sizes and stages, and a hurricane. For precipitating systems that are large relative to the PR footprint size, PR reflectivity profiles compare very well to high-resolution measurements thresholded to the PR minimum reflectivity, and derived variables such as bright band height and rain types are accurate, even at high PR incidence angles. It was found that for, the PR reflectivity of convective cells small relative to the PR footprint is weaker than in reality. Some of these differences can be explained by non-uniform beam filling. For other cases where strong reflectivity gradients occur within a PR footprint, the reflectivity distribution is spread out due to filtering by the PR antenna illumination pattern. In these cases, rain type classification may err and be biased towards the stratiform type, and the average reflectivity tends to be underestimated. The limited sensitivity of the PR implies that the upper regions of precipitation systems remain undetected and that the PR storm top height estimate is unreliable, usually underestimating the actual storm top height. This applies to all cases but the discrepancy is larger for smaller cells where limited sensitivity is compounded

  12. Topography of the lunar poles from radar interferometry: a survey of cold trap locations.

    PubMed

    Margot, J L; Campbell, D B; Jurgens, R F; Slade, M A

    1999-06-04

    Detailed topographic maps of the lunar poles have been obtained by Earth-based radar interferometry with the 3.5-centimeter wavelength Goldstone Solar System Radar. The interferometer provided maps 300 kilometers by 1000 kilometers of both polar regions at 150-meter spatial resolution and 50-meter height resolution. Using ray tracing, these digital elevation models were used to locate regions that are in permanent shadow from solar illumination and may harbor ice deposits. Estimates of the total extent of shadowed areas poleward of 87.5 degrees latitude are 1030 and 2550 square kilometers for the north and south poles, respectively.

  13. Honolulu, Hawaii Radar Image, Wrapped Color as Height

    NASA Technical Reports Server (NTRS)

    2000-01-01

    This topographic radar image shows the city of Honolulu, Hawaii and adjacent areas on the island of Oahu. Honolulu lies on the south shore of the island, right of center of the image. Just below the center is Pearl Harbor, marked by several inlets and bays. Runways of the airport can be seen to the right of Pearl Harbor. Diamond Head, an extinct volcanic crater, is a blue circle along the coast right of center. The Koolau mountain range runs through the center of the image. The steep cliffs on the north side of the range are thought to be remnants of massive landslides that ripped apart the volcanic mountains that built the island thousands of years ago. On the north shore of the island are the Mokapu Peninsula and Kaneohe Bay. High resolution topographic data allow ecologists and planners to assess the effects of urban development on the sensitive ecosystems in tropical regions.

    This image combines two types of data from the Shuttle Radar Topography Mission. The image brightness corresponds to the strength of the radar signal reflected from the ground, while colors show the elevation as measured by SRTM. Each cycle of colors (from pink through blue back to pink) represents an equal amount of elevation difference (400 meters, or 1300 feet) similar to contour lines on a standard topographic map. This image contains about 2400 meters (8000 feet) of total relief.

    The Shuttle Radar Topography Mission (SRTM), launched on February 11,2000, uses the same radar instrument that comprised the Spaceborne Imaging Radar-C/X-Band Synthetic Aperture Radar (SIR-C/X-SAR) that flew twice on the Space Shuttle Endeavour in 1994. The mission is designed to collect three-dimensional measurements of the Earth's surface. To collect the 3-D data, engineers added a 60-meter-long (200-foot) mast, an additional C-band imaging antenna and improved tracking and navigation devices. The mission is a cooperative project between the National Aeronautics and Space Administration (NASA

  14. Los Angeles, California, Radar Image, Wrapped Color as Height

    NASA Technical Reports Server (NTRS)

    2000-01-01

    This topographic radar image shows the relationships of the dense urban development of Los Angeles and the natural contours of the land. The image includes the Pacific Ocean on the left, the flat Los Angeles Basin across the center, and the steep ranges of the Santa Monica and Verdugo mountains along the top. The two dark strips near the coast at lower left are the runways of Los Angeles International Airport. Downtown Los Angeles is the bright yellow and pink area at lower center. Pasadena, including the Rose Bowl, are seen half way down the right edge of the image. The communities of Glendale and Burbank, including the Burbank Airport, are seen at the center of the top edge of the image. Hazards from earthquakes, floods and fires are intimately related to the topography in this area. Topographic data and other remote sensing images provide valuable information for assessing and mitigating the natural hazards for cities such as Leangles.

    This image combines two types of data from the Shuttle Radar Topography Mission. The image brightness corresponds to the strength of the radar signal reflected from the ground, while colors show the elevation as measured by SRTM. Each cycle of colors (from pink through blue back to pink) represents an equal amount of elevation difference (400 meters, or 1300 feet) similar to contour lines on a standard topographic map. This image contains about 2400 meters (8000 feet) of total relief.

    The Shuttle Radar Topography Mission (SRTM), launched on February 11,2000, uses the same radar instrument that comprised the Spaceborne Imaging Radar-C/X-Band Synthetic Aperture Radar (SIR-C/X-SAR) that flew twice on the Space Shuttle Endeavour in 1994. The mission is designed to collect three-dimensional measurements of the Earth's surface. To collect the 3-D data, engineers added a 60-meter-long (200-foot) mast, an additional C-band imaging antenna and improved tracking and navigation devices. The mission is a cooperative project between

  15. Space Radar Image of Karisoke & Virunga Volcanoes

    NASA Technical Reports Server (NTRS)

    1994-01-01

    vegetation maps of the area to aid in their studies of the last 650 mountain gorillas in the world. The faint lines above the bamboo forest are the result of agricultural terracing by the people who live in the region. Spaceborne Imaging Radar-C and X-Synthetic Aperture Radar (SIR-C/X-SAR) is part of NASA's Mission to Planet Earth. The radars illuminate Earth with microwaves, allowing detailed observations at any time, regardless of weather or sunlight conditions. SIR-C/X-SAR uses three microwave wavelengths: L-band (24 cm), C-band (6 cm) and X-band (3 cm). The multi-frequency data will be used by the international scientific community to better understand the global environment and how it is changing. The SIR-C/X-SAR data, complemented by aircraft and ground studies, will give scientists clearer insights into those environmental changes which are caused by nature and those changes which are induced by human activity. SIR-C was developed by NASA's Jet Propulsion Laboratory. X-SAR was developed by the Dornier and Alenia Spazio companies for the German space agency, Deutsche Agentur fuer Raumfahrtangelegenheiten (DARA), and the Italian space agency, Agenzia Spaziale Italiana (ASI), with the Deutsche Forschungsanstalt fuer Luft und Raumfahrt e.V. (DLR), the major partner in science, operations and data processing of X-SAR.

  16. Space Radar Image of Kilauea, Hawaii

    NASA Technical Reports Server (NTRS)

    1999-01-01

    This color composite C-band and L-band image of the Kilauea volcano on the Big Island of Hawaii was acquired by the Spaceborne Imaging Radar-C/X-band Synthetic Aperture Radar (SIR-C/X-SAR) flying on space shuttle Endeavour. The city of Hilo can be seen at the top. The image shows the different types of lava flows around the crater Pu'u O'o. Ash deposits which erupted in 1790 from the summit of Kilauea volcano show up as dark in this image, and fine details associated with lava flows which erupted in 1919 and 1974 can be seen to the south of the summit in an area called the Ka'u Desert. In addition, the other historic lava flows created in 1881 and 1984 from Mauna Loa volcano (out of view to the left of this image) can be easily seen despite the fact that the surrounding area is covered by forest. Such information will be used to map the extent of such flows, which can pose a hazard to the subdivisions of Hilo. Highway 11 is the linear feature running from Hilo to the Kilauea volcano. The Kilauea volcano has been almost continuously active for more than the last 11 years. Field teams that were on the ground specifically to support these radar observations report that there was vigorous surface activity about 400 meters (one-quarter mile) inland from the coast. A moving lava flow about 200 meters (660 feet) in length was observed at the time of the shuttle overflight, raising the possibility that subsequent images taken during this mission will show changes in the landscape. This image is centered at 19.2 degrees north latitude and 155.2 degrees west longitude. Spaceborne Imaging Radar-C and X-Synthetic Aperture Radar (SIR-C/X-SAR) is part of NASA's Mission to Planet Earth. The radars illuminate Earth with microwaves allowing detailed observations at any time, regardless of weather or sunlight conditions. SIR-C/X-SAR uses three microwave wavelengths: L-band (24 cm), C-band (6 cm) and X-band (3 cm). The multi-frequency data will be used by the international scientific

  17. Space Radar Image of Long Island Optical/Radar

    NASA Technical Reports Server (NTRS)

    1994-01-01

    This pair of images of the Long Island, New York region is a comparison of an optical photograph (top) and a radar image (bottom), both taken in darkness in April 1994. The photograph at the top was taken by the Endeavour astronauts at about 3 a.m. Eastern time on April 20, 1994. The image at the bottom was acquired at about the same time four days earlier on April 16,1994 by the Spaceborne Imaging Radar-C/X-Band Synthetic Aperture Radar (SIR-C/X-SAR) system aboard the space shuttle Endeavour. Both images show an area approximately 100 kilometers by 40 kilometers (62 miles by 25 miles) that is centered at 40.7 degrees North latitude and 73.5 degrees West longitude. North is toward the upper right. The optical image is dominated by city lights, which are particularly bright in the densely developed urban areas of New York City located on the left half of the photo. The brightest white zones appear on the island of Manhattan in the left center, and Central Park can be seen as a darker area in the middle of Manhattan. To the northeast (right) of the city, suburban Long Island appears as a less densely illuminated area, with the brightest zones occurring along major transportation and development corridors. Since radar is an active sensing system that provides its own illumination, the radar image shows a great amount of surface detail, despite the night-time acquisition. The colors in the radar image were obtained using the following radar channels: red represents the L-band (horizontally transmitted and received); green represents the L-band (horizontally transmitted and vertically received); blue represents the C-band (horizontally transmitted and vertically received). In this image, the water surface - the Atlantic Ocean along the bottom edge and Long Island Sound shown at the top edge - appears red because small waves at the surface strongly reflect the horizontally transmitted and received L-band radar signal. Networks of highways and railroad lines are clearly

  18. Radar Sounding of Mars with MARSIS

    NASA Astrophysics Data System (ADS)

    Plaut, J. J.; Picardi, G.; Orosei, R.; Gurnett, D. A.

    2009-12-01

    MARSIS, the Mars Advanced Radar for Subsurface and Ionospheric Sounding, is a radar sounder that has been observing Mars from the Mars Express orbiter since June 2005. MARSIS works in the range of 1.3 to 5.5 MHz, and includes significant onboard data summing. MARSIS also operates in an Active Ionospheric Sounding mode down to 0.1 MHz to capture echoes from the topside of the ionosphere. MARSIS signals easily penetrate the polar layered deposits (PLD), usually to their basal contact with the substrate. The typically strong echo return from the lower interface of the PLD indicates that only minor attenuation of the radar signal is occurring within the PLD, implying a composition of nearly pure water ice. MARSIS data have been used to map the bed of the polar deposits to their maximum depth of over 3.5 km in the south. In the north, MARSIS delineates the extent of the “basal unit,” a sediment-laden icy layer that makes up more than a third of the total volume of the topographic cap. In both polar regions, the bed topography does not display a regional-scale deflection that might be expected from a flexural response to the PLD load, indicating a thick elastic lithosphere in these regions. Subsurface interfaces in the low latitudes of Mars are also being mapped by MARSIS, in the equatorial Medusae Fossae Formation. MARSIS has not detected any unambiguous evidence for sizable shallow aquifers. While it is possible that such features exist, the lack of detection more likely indicates that liquid water is not abundant in the shallow (< several km) subsurface of Mars. However, water ice is abundant in the polar regions, including a large area surrounding the polar layered deposits that is associated with the Dorsa Argentea Formation. In addition, analysis of the MARSIS surface echo strength suggests that a substantial fraction of the upper km of the subsurface of the northern plains may be ice-rich. In its ionospheric mode, MARSIS has characterized the complex structure

  19. Gadanki Ionospheric Radar Interferometer (GIRI): System Description, Capabilities and Observations

    NASA Astrophysics Data System (ADS)

    Durga rao, Meka; Jayaraman, Achuthan; Patra, Amit; Kamaraj, Pandian; Jayaraj, Katta; Raghavendra, J.; Yasodha, Polisetti

    2016-07-01

    A 30-MHz radar has been developed at National Atmospheric Research Laboratory for dedicated probing of ionosphere and to study the low latitude ionospheric plasma irregularities. The radar has the beam steering capability to scan a larger part of the sky up to ±45o in East-West direction, which will overcome the limitation of slit camera picture obtained by the fixed beam of the Gadanki MST radar on the ionospheric plasma irregularity/structures. The system is also configured for pulse-to-pulse beam steering, employs multi-channel receiving system to carryout Interferometry/Imaging experiments. The radar system employs 20x8 phased antenna array, Direct Digital Synthesizers to generate pulse coded excitation signals, high power solid-state Transmit-Receive modules to generate a peak power of 150 kW, low loss coaxial beam forming and feeder network and multi-channel direct IF digital receiver. Round-the-clock observations are being made with uninterrupted operations and high quality E-and F-Region Range-Time-Intensity and conical maps are obtained with the system. In this paper we present, the system design philosophy, realization, initial observations and also the capability of the system to augment for Meteor observations.

  20. Determining Greenland Ice Sheet Accumulation Rates from Radar Remote Sensing

    NASA Technical Reports Server (NTRS)

    Jezek, Kenneth C.

    2002-01-01

    An important component of NASA's Program for Arctic Regional Climate Assessment (PARCA) is a mass balance investigation of the Greenland Ice Sheet. The mass balance is calculated by taking the difference between the areally Integrated snow accumulation and the net ice discharge of the ice sheet. Uncertainties in this calculation Include the snow accumulation rate, which has traditionally been determined by interpolating data from ice core samples taken from isolated spots across the ice sheet. The sparse data associated with ice cores juxtaposed against the high spatial and temporal resolution provided by remote sensing , has motivated scientists to investigate relationships between accumulation rate and microwave observations as an option for obtaining spatially contiguous estimates. The objective of this PARCA continuation proposal was to complete an estimate of surface accumulation rate on the Greenland Ice Sheet derived from C-band radar backscatter data compiled in the ERS-1 SAR mosaic of data acquired during, September-November, 1992. An empirical equation, based on elevation and latitude, is used to determine the mean annual temperature. We examine the influence of accumulation rate, and mean annual temperature on C-band radar backscatter using a forward model, which incorporates snow metamorphosis and radar backscatter components. Our model is run over a range of accumulation and temperature conditions. Based on the model results, we generate a look-up table, which uniquely maps the measured radar backscatter, and mean annual temperature to accumulation rate. Our results compare favorably with in situ accumulation rate measurements falling within our study area.

  1. Radar TopoMapper concept for planetary exploration

    NASA Astrophysics Data System (ADS)

    Madsen, Soren N.; Lou, Yun-Ling; Hensley, Scott; Harvey, Wayne L.; McKinnon, William B.

    2004-12-01

    Topographic information is key to interpreting the geology and geophysics of planetary bodies such as the icy Galilean satellites. Traditionally elevation information has been derived from stereo-photogrammetry, but the last couple of decades have offered new techniques, including radar interferometry, photoclinometry (shape from shading) and laser altimetry. Combining synthetic aperture radar (SAR) technology with interferometry (InSAR) enables high resolution imaging with elevation information at each image point. With two appropriately spaced antennas on a spacecraft, single-pass imaging radar interferometry can provide wide swath topographic data, independent of solar illumination, as was recently demonstrated on Earth by the Shuttle Topographic Radar Mission (SRTM; www.jpl.nasa.gov/srtm). We will present the science requirements, measurement principle, a straw-man"s design, and the predicted performance of a "compact SRTM" which could be flown on NASA missions such as the proposed Jupiter Icy Moons Orbiter (JIMO). In this paper we discuss challenges, including the calibration strategy and critical technology elements such as the high power RF-amplifier. We expect that the performance, both in terms of elevation accuracy and mapping rate would suffice to 1) determine topography on local and regional scales; 2) search for active geological change on the time scale of JIMO"s orbit around, e.g., Europa (30-60 days); and 3) determine the global tidal amplitude at Europa, Callisto, and Ganymede, which would constitute direct proof of the existence of oceans in all three icy moons.

  2. Magellan radar to reveal secrets of enshrouded Venus

    NASA Technical Reports Server (NTRS)

    Saunders, R. Stephen

    1990-01-01

    Imaging Venus with a synthetic aperture radar (SAR) with 70 percent global coverage at 1-km optical line-pair resolution to provide a detailed global characterization of the volcanic land-forms on Venus by an integration of image data with altimetry is discussed. The Magellan radar system uses navigation predictions to preset the radar data collection parameters. The data are collected in such a way as to preserve the Doppler signature of surface elements and later they are transmitted to the earth for processing into high-resolution radar images. To maintain high accuracy, a complex on-board filter algorithm allows the altitude control logic to respond only to a narrow range of expected photon intensity levels and only to signals that occur within a small predicted interval of time. Each mapping pass images a swath of the planet that varies in width from 20 to 25 km. Since the orbital plane of the spacecraft remains fixed in the inertial space, the slow rotation of Venus continually brings new areas into view of the spacecraft.

  3. Synthetic aperture radar and interferometry development at Sandia National Laboratories

    SciTech Connect

    1993-04-01

    Environmental monitoring, earth-resource mapping, and military systems require broad-area imaging at high resolutions. Many times the imagery must be acquired in inclement weather or during night as well as day. Synthetic aperture radar (SAR) provides such a capability. SAR systems take advantage of the long-range propagation characteristics of radar signals and the complex information processing capability of modern digital electronics to provide high resolution imagery. SAR complements photographic and other optical imaging capabilities because of the minimum constrains on time-of-day and atmospheric conditions and because of the unique responses of terrain and cultural targets to radar frequencies. Interferometry is a method for generating a three-dimensional image of terrain. The height projection is obtained by acquiring two SAR images from two slightly differing locations. It is different from the common method of stereoscopic imaging for topography. The latter relies on differing geometric projections for triangulation to define the surface geometry whereas interferometry relies on differences in radar propagation times between the two SAR locations. This paper presents the capabilities of SAR, explains how SAR works, describes a few SAR applications, provides an overview of SAR development at Sandia, and briefly describes the motion compensation subsystem.

  4. Magellan radar to reveal secrets of enshrouded Venus

    NASA Astrophysics Data System (ADS)

    Saunders, R. Stephen

    1990-09-01

    Imaging Venus with a synthetic aperture radar (SAR) with 70 percent global coverage at 1-km optical line-pair resolution to provide a detailed global characterization of the volcanic land-forms on Venus by an integration of image data with altimetry is discussed. The Magellan radar system uses navigation predictions to preset the radar data collection parameters. The data are collected in such a way as to preserve the Doppler signature of surface elements and later they are transmitted to the earth for processing into high-resolution radar images. To maintain high accuracy, a complex on-board filter algorithm allows the altitude control logic to respond only to a narrow range of expected photon intensity levels and only to signals that occur within a small predicted interval of time. Each mapping pass images a swath of the planet that varies in width from 20 to 25 km. Since the orbital plane of the spacecraft remains fixed in the inertial space, the slow rotation of Venus continually brings new areas into view of the spacecraft.

  5. Online clustering algorithms for radar emitter classification.

    PubMed

    Liu, Jun; Lee, Jim P Y; Senior; Li, Lingjie; Luo, Zhi-Quan; Wong, K Max

    2005-08-01

    Radar emitter classification is a special application of data clustering for classifying unknown radar emitters from received radar pulse samples. The main challenges of this task are the high dimensionality of radar pulse samples, small sample group size, and closely located radar pulse clusters. In this paper, two new online clustering algorithms are developed for radar emitter classification: One is model-based using the Minimum Description Length (MDL) criterion and the other is based on competitive learning. Computational complexity is analyzed for each algorithm and then compared. Simulation results show the superior performance of the model-based algorithm over competitive learning in terms of better classification accuracy, flexibility, and stability.

  6. European coordination for coastal HF radar data in EMODnet Physics

    NASA Astrophysics Data System (ADS)

    Mader, Julien; Novellino, Antonio; Gorringe, Patrick; Griffa, Annalisa; Schulz-Stellenfleth, Johannes; Montero, Pedro; Montovani, Carlo; Ayensa, Garbi; Vila, Begoña; Rubio, Anna; Sagarminaga, Yolanda

    2015-04-01

    Historically, joint effort has been put on observing open ocean, organizing, homogenizing, sharing and reinforcing the impact of the acquired information based on one technology: ARGO with profilers Argo floats, EuroSites, ESONET-NoE, FixO3 for deep water platforms, Ferrybox for stations in ships of opportunities, and GROOM for the more recent gliders. This kind of networking creates synergies and makes easier the implementation of this source of data in the European Data exchange services like EMODnet, ROOSs portals, or any applied services in the Blue economy. One main targeted improvement in the second phase of EMODnet projects is the assembling of data along coastline. In that sense, further coordination is recommended between platform operators around a specific technology in order to make easier the implementation of the data in the platforms (4th EuroGOOS DATAMEQ WG). HF radar is today recognized internationally as a cost-effective solution to provide high spatial and temporal resolution current maps (depending on the instrument operation frequency, covering from a few kilometres offshore up to 200 km) that are needed for many applications for issues related to ocean surface drift or sea state characterization. Significant heterogeneity still exists in Europe concerning technological configurations, data processing, quality standards and data availability. This makes more difficult the development of a significant network for achieving the needed accessibility to HF Radar data for a pan European use. EuroGOOS took the initiative to lead and coordinate activities within the various observation platforms by establishing a number of Ocean Observing Task Teams such as HF-Radars. The purpose is to coordinate and join the technological, scientific and operational HF radar communities at European level. The goal of the group is on the harmonization of systems requirements, systems design, data quality, improvement and proof of the readiness and standardization of

  7. Space Radar Image of Missoula, Montana in 3-D

    NASA Technical Reports Server (NTRS)

    1994-01-01

    This is a three-dimensional perspective view of Missoula, Montana, created by combining two spaceborne radar images using a technique known as interferometry. Visualizations like this are useful because they show scientists the shapes of the topographic features such as mountains and valleys. This technique helps to clarify the relationships of the different types of materials on the surface detected by the radar. The view is looking north-northeast. The blue circular area at the lower left corner is a bend of the Bitterroot River just before it joins the Clark Fork, which runs through the city. Crossing the Bitterroot River is the bridge of U.S. Highway 93. Highest mountains in this image are at elevations of 2,200 meters (7,200 feet). The city is about 975 meters (3,200 feet) above sea level. The bright yellow areas are urban and suburban zones, dark brown and blue-green areas are grasslands, bright green areas are farms, light brown and purple areas are scrub and forest, and bright white and blue areas are steep rocky slopes. The two radar images were taken on successive days by the Spaceborne Imaging Radar-C/X-band Synthetic Aperture Radar (SIR-C/X-SAR) onboard the space shuttle Endeavour in October 1994. The digital elevation map was produced using radar interferometry, a process in which radar data are acquired on different passes of the space shuttle. The two data passes are compared to obtain elevation information. Radar image data are draped over the topography to provide the color with the following assignments: red is L-band vertically transmitted, vertically received; green is C-band vertically transmitted, vertically received; and blue are differences seen in the L-band data between the two days. This image is centered near 46.9 degrees north latitude and 114.1 degrees west longitude. No vertical exaggeration factor has been applied to the data. SIR-C/X-SAR, a joint mission of the German, Italian and United States space agencies, is part of NASA

  8. Recent Advances in Radar Polarimetry and Polarimetric SAR Interferometry

    NASA Technical Reports Server (NTRS)

    Boerner, Wolfgang-Martin

    2005-01-01

    The development of Radar Polarimetry and Radar Interferometry is advancing rapidly, and these novel radar technologies are revamping Synthetic Aperture Radar Imaging decisively. In this exposition the successive advancements are sketched; beginning with the fundamental formulations and high-lighting the salient points of these diverse remote sensing techniques. Whereas with radar polarimetry the textural fine-structure, target-orientation and shape, symmetries and material constituents can be recovered with considerable improvements above that of standard amplitude-only Polarization Radar ; with radar interferometry the spatial (in depth) structure can be explored. In Polarimetric-Interferometric Synthetic Aperture Radar (POL-IN-SAR) Imaging it is possible to recover such co-registered textural plus spatial properties simultaneously. This includes the extraction of Digital Elevation Maps (DEM) from either fully Polarimetric (scattering matrix) or Interferometric (dual antenna) SAR image data takes with the additional benefit of obtaining co-registered three-dimensional POL-IN-DEM information. Extra-Wide-Band POL-IN-SAR Imaging - when applied to Repeat-Pass Image Overlay Interferometry - provides differential background validation and measurement, stress assessment, and environmental stress-change monitoring capabilities with hitherto unattained accuracy, which are essential tools for improved global biomass estimation. More recently, by applying multiple parallel repeat-pass EWB-POL-D(RP)-IN-SAR imaging along stacked (altitudinal) or displaced (horizontal) flight-lines will result in Tomographic (Multi- Interferometric) Polarimetric SAR Stereo-Imaging , including foliage and ground penetrating capabilities. It is shown that the accelerated advancement of these modern EWB-POL-D(RP)-IN-SAR imaging techniques is of direct relevance and of paramount priority to wide-area dynamic homeland security surveillance and local-to-global environmental ground-truth measurement

  9. All-digital radar architecture

    NASA Astrophysics Data System (ADS)

    Molchanov, Pavlo A.

    2014-10-01

    All digital radar architecture requires exclude mechanical scan system. The phase antenna array is necessarily large because the array elements must be co-located with very precise dimensions and will need high accuracy phase processing system for aggregate and distribute T/R modules data to/from antenna elements. Even phase array cannot provide wide field of view. New nature inspired all digital radar architecture proposed. The fly's eye consists of multiple angularly spaced sensors giving the fly simultaneously thee wide-area visual coverage it needs to detect and avoid the threats around him. Fly eye radar antenna array consist multiple directional antennas loose distributed along perimeter of ground vehicle or aircraft and coupled with receiving/transmitting front end modules connected by digital interface to central processor. Non-steering antenna array allows creating all-digital radar with extreme flexible architecture. Fly eye radar architecture provides wide possibility of digital modulation and different waveform generation. Simultaneous correlation and integration of thousands signals per second from each point of surveillance area allows not only detecting of low level signals ((low profile targets), but help to recognize and classify signals (targets) by using diversity signals, polarization modulation and intelligent processing. Proposed all digital radar architecture with distributed directional antenna array can provide a 3D space vector to the jammer by verification direction of arrival for signals sources and as result jam/spoof protection not only for radar systems, but for communication systems and any navigation constellation system, for both encrypted or unencrypted signals, for not limited number or close positioned jammers.

  10. Interpreting Radar View near Mars' South Pole, Orbit 1334

    NASA Technical Reports Server (NTRS)

    2006-01-01

    A radargram from the Shallow Subsurface Radar instrument (SHARAD) on NASA's Mars Reconnaissance Orbiter is shown in the upper-right panel and reveals detailed structure in the polar layered deposits of the south pole of Mars.

    The sounding radar collected the data presented here during orbit 1334 of the mission, on Nov. 8, 2006.

    The horizontal scale in the radargram is distance along the ground track. It can be referenced to the ground track map shown in the lower right. The radar traversed from about 75 to 85 degrees south latitude, or about 590 kilometers (370 miles). The ground track map shows elevation measured by the Mars Orbiter Laser Altimeter on NASA's Mars Global Surveyor orbiter. Green indicates low elevation; reddish-white indicates higher elevation. The traverse proceeds up onto a plateau formed by the layers.

    The vertical scale on the radargram is time delay of the radar signals reflected back to Mars Reconnaissance Orbiter from the surface and subsurface. For reference, using an assumed velocity of the radar waves in the subsurface, time is converted to depth below the surface at one place: about 1,500 meters (5,000 feet) to one of the deeper subsurface reflectors. The color scale varies from black for weak reflections to white for strong reflections.

    The middle panel shows mapping of the major subsurface reflectors, some of which can be traced for a distance of 100 kilometers (60 miles) or more. The layers are not all horizontal and the reflectors are not always parallel to one another. Some of this is due to variations in surface elevation, which produce differing velocity path lengths for different reflector depths. However, some of this behavior is due to spatial variations in the deposition and removal of material in the layered deposits, a result of the recent climate history of Mars.

    The Shallow Subsurface Radar was provided by the Italian Space Agency (ASI). Its operations are led by the University of Rome and its

  11. Interpreting Radar View near Mars' South Pole, Orbit 1360

    NASA Technical Reports Server (NTRS)

    2006-01-01

    A radargram from the Shallow Subsurface Radar instrument (SHARAD) on NASA's Mars Reconnaissance Orbiter is shown in the upper-right panel and reveals detailed structure in the polar layered deposits of the south pole of Mars.

    The sounding radar collected the data presented here during orbit 1360 of the mission, on Nov. 10, 2006.

    The horizontal scale in the radargram is distance along the ground track. It can be referenced to the ground track map shown in the lower right. The radar traversed from about 74 degrees to 85 degrees south latitude, or about 650 kilometers (400 miles). The ground track map shows elevation measured by the Mars Orbiter Laser Altimeter on NASA's Mars Global Surveyor orbiter. Green indicates low elevation; reddish-white indicates higher elevation. The traverse proceeds up onto a plateau formed by the layers.

    The vertical scale on the radargram is time delay of the radar signals reflected back to Mars Reconnaissance Orbiter from the surface and subsurface. For reference, using an assumed velocity of the radar waves in the subsurface, time is converted to depth below the surface at one place: about 800 meters (2,600 feet) to one of the strongest subsurface reflectors. This reflector marks the base of the polar layered deposits. The color scale varies from black for weak reflections to white for strong reflections.

    The middle panel shows mapping of the major subsurface reflectors, some of which can be traced for a distance of 100 kilometers (60 miles) or more. The layering manifests the recent climate history of Mars, recorded by the deposition and removal of ice and dust.

    The Shallow Subsurface Radar was provided by the Italian Space Agency (ASI). Its operations are led by the University of Rome and its data are analyzed by a joint U.S.-Italian science team. NASA's Jet Propulsion Laboratory, a division of the California Institute of Technology, Pasadena, manages the Mars Reconnaissance Orbiter for the NASA Science

  12. Semi-distributed modelling of basin hydrology with radar and gauged precipitation

    NASA Astrophysics Data System (ADS)

    Kalinga, Oscar Anthony; Yew Gan, Thian

    2006-11-01

    Even though gauged rainfall data generally provide accurate depth measurements, sparsely spaced, gauging stations cannot effectively account for the spatial variability of precipitation at basin scale. On the other hand, radar data such as the WSR-88D stage III radar rainfall data can generally capture the spatial variability of rainfall fields, but tends to underestimate rainfall depth of stratiform storms, or both convective and stratiform storms if a storm is of low intensity. To take advantage of both the strength of radar data (mapping accurate spatial variability of rainfall) and that of gauge data (accurate depth measurements), the two data sets were merged together by the Statistical Objective Analysis (SOA) scheme. The event-based hydrologic experiments using a semi-distributed, physics-based hydrologic model (distributed physically based hydrologic model using remote sensing, DPHM-RS) revealed that WSR-88D Stage III radar rainfall data simulated more accurate runoff hydrographs than gauged data for convective storms but less accurate runoff hydrograph for stratiform storms, because radars measured slightly more rainfall than gauges for convective storms, but substantially less rainfall for stratiform storms. However, after merging WSR-88D stage III radar data with gauge data by SOA, the radar's underestimation of stratiform storm depth decreased substantially, but the adjustment could be counter productive for convective storms. Results show that rainfall spatial variability, depths, and hydrologic model resolution play a major role on the accuracy of simulated runoff volumes and peak flows. Copyright

  13. Arecibo radar imagery of Mars: The major volcanic provinces

    NASA Astrophysics Data System (ADS)

    Harmon, John K.; Nolan, Michael C.; Husmann, Diana I.; Campbell, Bruce A.

    2012-08-01

    We present Earth-based radar images of Mars obtained with the upgraded Arecibo S-band (λ = 12.6 cm) radar during the 2005-2012 oppositions. The imaging was done using the same long-code delay-Doppler technique as for the earlier (pre-upgrade) imaging but at a much higher resolution (˜3 km) and, for some regions, a more favorable sub-Earth latitude. This has enabled us to make a more detailed and complete mapping of depolarized radar reflectivity (a proxy for small-scale surface roughness) over the major volcanic provinces of Tharsis, Elysium, and Amazonis. We find that vast portions of these regions are covered by radar-bright lava flows exhibiting circular polarization ratios close to unity, a characteristic that is uncommon for terrestrial lavas and that is a likely indicator of multiple scattering from extremely blocky or otherwise highly disrupted flow surfaces. All of the major volcanoes have radar-bright features on their shields, although the brightness distribution on Olympus Mons is very patchy and the summit plateau of Pavonis Mons is entirely radar-dark. The older minor shields (paterae and tholi) are largely or entirely radar-dark, which is consistent with mantling by dust or pyroclastic material. Other prominent radar-dark features include: the "fan-shaped deposits", possibly glacial, associated with the three major Tharsis Montes shields; various units of the Medusae Fossae Formation; a region south and west of Biblis Patera where "Stealth" deposits appear to obscure Tharsis flows; and a number of "dark-halo craters" with radar-absorbing ejecta blankets deposited atop surrounding bright flows. Several major bright features in Tharsis are associated with off-shield lava flows; these include the Olympus Mons basal plains, volcanic fields east and south of Pavonis Mons, the Daedalia Planum flows south of Arsia Mons, and a broad expanse of flows extending east from the Tharsis Montes to Echus Chasma. The radar-bright lava plains in Elysium are

  14. Space Radar Image of West Texas - SAR scan

    NASA Technical Reports Server (NTRS)

    1999-01-01

    This radar image of the Midland/Odessa region of West Texas, demonstrates an experimental technique, called ScanSAR, that allows scientists to rapidly image large areas of the Earth's surface. The large image covers an area 245 kilometers by 225 kilometers (152 miles by 139 miles). It was obtained by the Spaceborne Imaging Radar-C/X-Band Synthetic Aperture Radar (SIR-C/X-SAR) flying aboard the space shuttle Endeavour on October 5, 1994. The smaller inset image is a standard SIR-C image showing a portion of the same area, 100 kilometers by 57 kilometers (62 miles by 35 miles) and was taken during the first flight of SIR-C on April 14, 1994. The bright spots on the right side of the image are the cities of Odessa (left) and Midland (right), Texas. The Pecos River runs from the top center to the bottom center of the image. Along the left side of the image are, from top to bottom, parts of the Guadalupe, Davis and Santiago Mountains. North is toward the upper right. Unlike conventional radar imaging, in which a radar continuously illuminates a single ground swath as the space shuttle passes over the terrain, a Scansar radar illuminates several adjacent ground swaths almost simultaneously, by 'scanning' the radar beam across a large area in a rapid sequence. The adjacent swaths, typically about 50 km (31 miles) wide, are then merged during ground processing to produce a single large scene. Illumination for this L-band scene is from the top of the image. The beams were scanned from the top of the scene to the bottom, as the shuttle flew from left to right. This scene was acquired in about 30 seconds. A normal SIR-C image is acquired in about 13 seconds. The ScanSAR mode will likely be used on future radar sensors to construct regional and possibly global radar images and topographic maps. The ScanSAR processor is being designed for 1996 implementation at NASA's Alaska SAR Facility, located at the University of Alaska Fairbanks, and will produce digital images from the

  15. Evidence for Crater Ejecta on Venus Tessera Terrain from Earth-Based Radar Images

    NASA Technical Reports Server (NTRS)

    Campbell, Bruce A.; Campbell, Donald B.; Morgan, Gareth A.; Carter, Lynn M.; Nolan, Michael C.; Chandler, John F.

    2014-01-01

    We combine Earth-based radar maps of Venus from the 1988 and 2012 inferior conjunctions, which had similar viewing geometries. Processing of both datasets with better image focusing and co-registration techniques, and summing over multiple looks, yields maps with 1-2 km spatial resolution and improved signal to noise ratio, especially in the weaker same-sense circular (SC) polarization. The SC maps are unique to Earth-based observations, and offer a different view of surface properties from orbital mapping using same-sense linear (HH or VV) polarization. Highland or tessera terrains on Venus, which may retain a record of crustal differentiation and processes occurring prior to the loss of water, are of great interest for future spacecraft landings. The Earth-based radar images reveal multiple examples of tessera mantling by impact ''parabolas'' or ''haloes'', and can extend mapping of locally thick material from Magellan data by revealing thinner deposits over much larger areas. Of particular interest is an ejecta deposit from Stuart crater that we infer to mantle much of eastern Alpha Regio. Some radar-dark tessera occurrences may indicate sediments that are trapped for longer periods than in the plains. We suggest that such radar information is important for interpretation of orbital infrared data and selection of future tessera landing sites.

  16. Exploring Subsurface Geology Using Radar Techniques: Experiments in Sahara and Consequences for Mars Exploration

    NASA Astrophysics Data System (ADS)

    Paillou, P.; Grandjean, G.; Heggy, E.; Farr, T.

    2004-05-01

    For several years, we have conducted a quantitative study of radar penetration performances in various desert arid environments. This study combines both SAR (Synthetic Aperture Radar) imaging from orbital and airborne platforms and in situ GPR (Ground Penetrating Radar) measurements. Laboratory characterization of various minerals and rocks are used as input to electromagnetic models such as IEM (Integral Equation Model) and FDTD (Finite Difference Time Domain) that describe the subsurface scattering process for inversion purposes. Several test sites were explored, mainly the Sahara. Our first experiment was realized in Republic of Djibouti, an arid volcanic area which is a good analog to Mars. We observed a very little radar penetration there because of the presence of iron oxides and salts in the subsurface that make the soil conductive [Paillou et al., GRL, 2001]. A more favorable site for radar penetration was then explored in southern Egypt: the Bir Safsaf area where buried river channels were discovered using orbital SAR images. We showed how to combine SAR and GPR in order to obtain a complete description of subsurface geology down to several meters [Paillou et al., IEEE TGRS, 2003]. Such field experiments were the basis for more systematic laboratory measurements of the electromagnetic properties of various rocks and minerals which were used in numerical models in order to simulate the performances of future Martian radars, e.g. MARSIS and NETLANDER low frequency radars [Heggy et al., Icarus, 2001; Berthelier et al., JGR, 2003; Heggy et al., JGR, 2003]. More recently, new explorations were conducted in Mauritania in order to demonstrate radar capacities for geologic mapping [Grandjean et al., Coll. Afr. Geol., 2004] and in Libya where radar discovered a double impact crater in the southern desert [Paillou et al., C.R. Geoscience, 2003]. More local radar experiments were also conducted on a test site located in France, the Pyla sand dune, where we observed

  17. Experimental Investigation into the Radar Anomalies on the Surface of Venus

    NASA Technical Reports Server (NTRS)

    Kohler, E.; Gavin, P.; Chevrier, V.; Johnson, Natasha M.

    2012-01-01

    Radar mapping of thc surface of Venus shows areas of high reflectivity (low emissivity) in the Venusian highlands at altitudes between 2.5-4.75 kilometers. The origin of the radar anomalies found in the Venusian highlands remains unclear. Most explanations of the potential causes for these radar anomalies come from theoretical work. Previous studies suggest increased surface roughness or materials with higher dielectric constants as well as surface atmospheric interactions. Several possible candidates of high-dielectric materials are tellurium) ferroelectric materials, and lead or bismuth sulfides. While previous studies have been influential in determining possible sources for the Venus anomalies, only a very few hypotheses have been verified via experimentation. This work intends to experimentally constrain the source of the radar anomalies on Venus. This study proposes to investigate four possible materials that could potentially cause the high reflectivities on the surface of Venus and tests their behavior under simulated Venusian conditions.

  18. Integrating Radar, Multispectral, and Landing Site Data for Analysis of the Lunar Surface

    NASA Technical Reports Server (NTRS)

    Campbell, B. A.; Campbell, D. B.; Thompson, T. W.; Hawke, B. R.

    1998-01-01

    Radar maps of the Moon have been produced since the late 1960s, and have been used by a number of authors to study the surface roughness, subsurface rock abundance, and dielectric properties of the lunar surface. These studies focused on a range of topics, including the depth and rock population of the regolith, crater ejecta blankets, pyroclastic mantling layers, and cryptomare deposits. Limited radar sounding data from the Apollo missions identified layering in some regions of the maria. As radar datasets have improved in resolution and calibration, it has become more possible to make quantitative comparisons between the backscatter properties of the Moon, other remote-sensing observations, and the ground truth provided by Surveyor photos and Apollo traverses. This presentation will focus on the results of recent studies of the lunar regolith that make use of these diverse sources of information, and discuss research directions that will be possible with radar data to be collected in the near future.

  19. Moving target detection in foliage using along track monopulse synthetic aperture radar imaging.

    PubMed

    Soumekh, M

    1997-01-01

    This paper presents a method for detecting moving targets embedded in foliage from the monostatic and bistatic synthetic aperture radar (SAR) data obtained via two airborne radars. The two radars, which are mounted on the same aircraft, have different coordinates in the along track (cross-range) domain. However, unlike the interferometric SAR systems used for topographic mapping, the two radars possess a common range and altitude (i.e., slant range). The resultant monopulse SAR images are used to construct difference and interferometric images for moving target detection. It is shown that the signatures of the stationary targets are weakened in these images. Methods for estimating a moving target's motion parameters are discussed. Results for an ultrawideband UHF SAR system are presented.

  20. Doppler-radar wind-speed measurements in tornadoes: A comparison of real and simulated spectra

    SciTech Connect

    Bluestein, H.B.; LaDue, J.G.; Stein, H.; Speheger, D.; Unruh, W.P.

    1993-03-01

    Bluestein and Unruh have discussed the advantages of using a portable doppler radar to map the wind field in tornadoes. during the spring of 1991 a storm-intercept team from the University of Oklahoma (OU) collected data near five supercell tornadoes in Oklahoma and Kansas. Details about the 1-W, 3-cm, 5-deg half-power beamwidth, CW/FM-CW Doppler radar we used and the methods of data collection and analysis are found in Bluestein and Unruh and Bluestein et al. Using the portable radar, we approximately doubled in only one year the number of tornado spectra that had been collected over a period of almost 20 years by NSSL`s fixed-site Doppler radar. In this paper we will compare observed tornado wind spectra with simulated wind spectra (Zmic and Doviak 1975) in order to learn more about tornado structure.