Science.gov

Sample records for radar image processing

  1. IEEE Proc. on Image Processing, Nov., 1994 1 STORM TRACKING IN DOPPLER RADAR IMAGES

    E-print Network

    Barron, John

    IEEE Proc. on Image Processing, Nov., 1994 1 STORM TRACKING IN DOPPLER RADAR IMAGES D. Krezeski 1 of Western Ontario London, Ontario, N6A 5B7 email: fmercer,barrong@csd.uwo.ca 2 King City Radar Station@aestor.dots.doe.ca ABSTRACT An automated tracking algorithm for doppler radar storms is presented. Potential storms in Doppler

  2. A study of image quality for radar image processing. [synthetic aperture radar imagery

    NASA Technical Reports Server (NTRS)

    King, R. W.; Kaupp, V. H.; Waite, W. P.; Macdonald, H. C.

    1982-01-01

    Methods developed for image quality metrics are reviewed with focus on basic interpretation or recognition elements including: tone or color; shape; pattern; size; shadow; texture; site; association or context; and resolution. Seven metrics are believed to show promise as a way of characterizing the quality of an image: (1) the dynamic range of intensities in the displayed image; (2) the system signal-to-noise ratio; (3) the system spatial bandwidth or bandpass; (4) the system resolution or acutance; (5) the normalized-mean-square-error as a measure of geometric fidelity; (6) the perceptual mean square error; and (7) the radar threshold quality factor. Selective levels of degradation are being applied to simulated synthetic radar images to test the validity of these metrics.

  3. Radar image processing module development program, phase 3

    NASA Technical Reports Server (NTRS)

    1977-01-01

    The feasibility of using charge coupled devices in an IPM for processing synthetic aperture radar signals onboard the NASA Convair 990 (CV990) aircraft was demonstrated. Radar data onboard the aircraft was recorded and processed using a CCD sampler and digital tape recorder. A description of equipment and testing was provided. The derivation of the digital presum filter was documented. Photographs of the sampler/tape recorder, real time display and circuit boards in the IPM were also included.

  4. Convective cell structures revealed by Mie laser radar observations and image data processing.

    PubMed

    Sasano, Y; Shimizu, H; Takeuchi, N

    1982-09-01

    Mie scattering laser radar has been used to study the structure of the convective mixed layer in optically clear air. Two-dimensional image data obtained by scanning measurements (PPI and RHI modes) have been processed using edge-enhancement techniques to display distinct structures within the convective layer. The structures of convective cells penetrating into upper clean air were very similar to those obtained previously by sodar, radar, and FM-cw radar. PMID:20396196

  5. Basics of Polar-Format algorithm for processing Synthetic Aperture Radar images.

    SciTech Connect

    Doerry, Armin Walter

    2012-05-01

    The purpose of this report is to provide a background to Synthetic Aperture Radar (SAR) image formation using the Polar Format (PFA) processing algorithm. This is meant to be an aid to those tasked to implement real-time image formation using the Polar Format processing algorithm.

  6. Nearshore Processes, Currents and Directional Wave Spectra Monitoring Using Coherent and Non-coherent Imaging Radars

    NASA Astrophysics Data System (ADS)

    Trizna, D.; Hathaway, K.

    2007-05-01

    Two new radar systems have been developed for real-time measurement of near-shore processes, and results are presented for measurements of ocean wave spectra, near-shore sand bar structure, and ocean currents. The first is a non-coherent radar based on a modified version of the Sitex radar family, with a data acquisition system designed around an ISR digital receiver card. The card operates in a PC computer with inputs from a Sitex radar modified for extraction of analogue signals for digitization. Using a 9' antenna and 25 kW transmit power system, data were collected during 2007 at the U.S. Army Corps of Engineers Field Research Facility (FRF), Duck, NC during winter and spring of 2007. The directional wave spectrum measurements made are based on using a sequence of 64 to 640 antenna rotations to form a snapshot series of radar images of propagating waves. A square window is extracted from each image, typically 64 x 64 pixels at 3-m resolution. Then ten sets of 64 windows are submitted to a three-dimensional Fast Fourier Transform process to generate radar image spectra in the frequency-wavenumber space. The relation between the radar image spectral intensity and wave spectral intensity derived from the FRF pressure gauge array was used for a test set of data, in order to establish a modulation transfer function (MTF) for each frequency component. For 640 rotations, 10 of such spectra are averaged for improved statistics. The wave spectrum so generated was compared for extended data sets beyond those used to establish the MTF, and those results are presented here. Some differences between the radar and pressure sensor data that are observed are found to be due to the influence of the wind field, as the radar echo image weakens for light winds. A model is developed to account for such an effect to improve the radar estimate of the directional wave spectrum. The radar ocean wave imagery is severely influenced only by extremely heavy rain-fall rates, so that acceptable quality were assured for most weather conditions on a diurnal basis using a modest tower height. A new coherent microwave radar has recently been developed by ISR and preliminary testing was conducted in the spring of 2007. The radar is based on the Quadrapus four-channel transceiver card, mixed up to microwave frequencies for pulse transmission and back down to base-band for reception. We use frequency-modulated pulse compression methods to obtain 3-m spatial resolution. A standard marine radar pedestal is used to house the microwave components, and rotating radar PPI images similar to marine radar images are obtained. Many of the methods used for the marine radar system have been transferred to the coherent imaging radar. New processing methods applied to the coherent data allow summing of radial velocity images to map mean currents in the near shore zone, such as rip currents. A pair of such radars operating with a few hundred meter separation can be used to map vector currents continuously in the near shore zone and in harbors on a timely basis. Results of preliminary testing of the system will be presented.

  7. Wavefront curvature limitations and compensation to polar format processing for synthetic aperture radar images.

    SciTech Connect

    Doerry, Armin Walter

    2006-01-01

    Limitations on focused scene size for the Polar Format Algorithm (PFA) for Synthetic Aperture Radar (SAR) image formation are derived. A post processing filtering technique for compensating the spatially variant blurring in the image is examined. Modifications to this technique to enhance its robustness are proposed.

  8. Synthetic-aperture imaging laser radar: laboratory demonstration and signal processing.

    PubMed

    Beck, Steven M; Buck, Joseph R; Buell, Walter F; Dickinson, Richard P; Kozlowski, David A; Marechal, Nicholas J; Wright, Timothy J

    2005-12-10

    The spatial resolution of a conventional imaging laser radar system is constrained by the diffraction limit of the telescope's aperture. We investigate a technique known as synthetic-aperture imaging laser radar (SAIL), which employs aperture synthesis with coherent laser radar to overcome the diffraction limit and achieve fine-resolution, long-range, two-dimensional imaging with modest aperture diameters. We detail our laboratory-scale SAIL testbed, digital signal-processing techniques, and image results. In particular, we report what we believe to be the first optical synthetic-aperture image of a fixed, diffusely scattering target with a moving aperture. A number of fine-resolution, well-focused SAIL images are shown, including both retroreflecting and diffuse scattering targets, with a comparison of resolution between real-aperture imaging and synthetic-aperture imaging. A general digital signal-processing solution to the laser waveform instability problem is described and demonstrated, involving both new algorithms and hardware elements. These algorithms are primarily data driven, without a priori knowledge of waveform and sensor position, representing a crucial step in developing a robust imaging system. PMID:16363787

  9. Synthetic-aperture imaging laser radar: laboratory demonstration and signal processing

    NASA Astrophysics Data System (ADS)

    Beck, Steven M.; Buck, Joseph R.; Buell, Walter F.; Dickinson, Richard P.; Kozlowski, David A.; Marechal, Nicholas J.; Wright, Timothy J.

    2005-12-01

    The spatial resolution of a conventional imaging laser radar system is constrained by the diffraction limit of the telescope's aperture. We investigate a technique known as synthetic-aperture imaging laser radar (SAIL), which employs aperture synthesis with coherent laser radar to overcome the diffraction limit and achieve fine-resolution, long-range, two-dimensional imaging with modest aperture diameters. We detail our laboratory-scale SAIL testbed, digital signal-processing techniques, and image results. In particular, we report what we believe to be the first optical synthetic-aperture image of a fixed, diffusely scattering target with a moving aperture. A number of fine-resolution, well-focused SAIL images are shown, including both retroreflecting and diffuse scattering targets, with a comparison of resolution between real-aperture imaging and synthetic-aperture imaging. A general digital signal-processing solution to the laser waveform instability problem is described and demonstrated, involving both new algorithms and hardware elements. These algorithms are primarily data driven, without a priori knowledge of waveform and sensor position, representing a crucial step in developing a robust imaging system.

  10. Imaging synthetic aperture radar

    DOEpatents

    Burns, Bryan L. (Tijeras, NM); Cordaro, J. Thomas (Albuquerque, NM)

    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.

  11. Insights into Titan's geology and hydrology based on enhanced image processing of Cassini RADAR data

    NASA Astrophysics Data System (ADS)

    Lucas, Antoine; Aharonson, Oded; Deledalle, Charles; Hayes, Alexander G.; Kirk, Randolph; Howington-Kraus, Elpitha

    2014-10-01

    The Cassini Synthetic Aperture Radar has been acquiring images of Titan's surface since October 2004. To date, 59% of Titan's surface has been imaged by radar, with significant regions imaged more than once. Radar data suffer from speckle noise hindering interpretation of small-scale features and comparison of reimaged regions for change detection. We present here a new image analysis technique that combines a denoising algorithm with mapping and quantitative measurements that greatly enhance the utility of the data and offers previously unattainable insights. After validating the technique, we demonstrate the potential improvement in understanding of surface processes on Titan and defining global mapping units, focusing on specific landforms including lakes, dunes, mountains, and fluvial features. Lake shorelines are delineated with greater accuracy. Previously unrecognized dissection by fluvial channels emerges beneath shallow methane cover. Dune wavelengths and interdune extents are more precisely measured. A significant refinement in producing digital elevation models is shown. Interactions of fluvial and aeolian processes with topographic relief is more precisely observed and understood than previously. Benches in bathymetry are observed in northern sea Ligeia Mare. Submerged valleys show similar depth suggesting that they are equilibrated with marine benches. These new observations suggest a liquid level increase in the northern sea, which may be due to changes on seasonal or longer timescales.

  12. Improving Ground Penetrating Radar Imaging in High Loss Environments by Coordinated System Development, Data Processing, Numerical Modeling, & Visualization

    SciTech Connect

    Wright, David L.

    2004-12-01

    Improving Ground Penetrating Radar Imaging in High Loss Environments by Coordinated System Development, Data Processing, Numerical Modeling, and Visualization Methods with Applications to Site Characterization EMSP Project 86992 Progress Report as of 9/2004.

  13. Radar Imaging Systems Joseph Charpentier

    E-print Network

    Radar Imaging Systems Joseph Charpentier Department of Computing Sciences Villanova University types of radar imaging systems; synthetic aperture radar (SAR), through-the-wall radar, and digital holographic near field radar. Each system surveyed experiments that improved the quality of the resulting

  14. Digital processing considerations for extraction of ocean wave image spectra from raw synthetic aperture radar data

    NASA Technical Reports Server (NTRS)

    Lahaie, I. J.; Dias, A. R.; Darling, G. D.

    1984-01-01

    The digital processing requirements of several algorithms for extracting the spectrum of a detected synthetic aperture radar (SAR) image from the raw SAR data are described and compared. The most efficient algorithms for image spectrum extraction from raw SAR data appear to be those containing an intermediate image formation step. It is shown that a recently developed compact formulation of the image spectrum in terms of the raw data is computationally inefficient when evaluated directly, in comparison with the classical method where matched-filter image formation is an intermediate result. It is also shown that a proposed indirect procedure for digitally implementing the same compact formulation is somewhat more efficient than the classical matched-filtering approach. However, this indirect procedure includes the image formation process as part of the total algorithm. Indeed, the computational savings afforded by the indirect implementation are identical to those obtained in SAR image formation processing when the matched-filtering algorithm is replaced by the well-known 'dechirp-Fourier transform' technique. Furthermore, corrections to account for slant-to-ground range conversion, spherical earth, etc., are often best implemented in the image domain, making intermediate image formation a valuable processing feature.

  15. Obstacle penetrating dynamic radar imaging system

    DOEpatents

    Romero, Carlos E. (Livermore, CA); Zumstein, James E. (Livermore, CA); Chang, John T. (Danville, CA); Leach, Jr.. Richard R. (Castro Valley, CA)

    2006-12-12

    An obstacle penetrating dynamic radar imaging system for the detection, tracking, and imaging of an individual, animal, or object comprising a multiplicity of low power ultra wideband radar units that produce a set of return radar signals from the individual, animal, or object, and a processing system for said set of return radar signals for detection, tracking, and imaging of the individual, animal, or object. The system provides a radar video system for detecting and tracking an individual, animal, or object by producing a set of return radar signals from the individual, animal, or object with a multiplicity of low power ultra wideband radar units, and processing said set of return radar signals for detecting and tracking of the individual, animal, or object.

  16. Generalized radar/radiometry imaging problems

    E-print Network

    Paper Generalized radar/radiometry imaging problems Ivan Prudyus, Sviatoslav Voloshynovskiy, Andriy- ing simulation based on radar, synthetic aperture radar (SAR) and radiometry systems are presented systems, synthetic aperture radar, spatio-temporal imaging. 1. Introduction Resolution of radar

  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. APQ-102 imaging radar digital image quality study

    NASA Technical Reports Server (NTRS)

    Griffin, C. R.; Estes, J. M.

    1982-01-01

    A modified APQ-102 sidelooking radar collected synthetic aperture radar (SAR) data which was digitized and recorded on wideband magnetic tape. These tapes were then ground processed into computer compatible tapes (CCT's). The CCT's may then be processed into high resolution radar images by software on the CYBER computer.

  19. Spaceborne Imaging Radar Project

    NASA Technical Reports Server (NTRS)

    Herman, Neil

    1986-01-01

    In June of 1985 the Project Initiation Agreement was signed by the Jet Propulsion Laboratory and the NASA Office of Space Science and Applications for the Spaceborne Imaging Radar Project (SIR). The thrust of the Spaceborne Imaging Radar Project is to continue the evolution of synthetic aperture radar (SAR) science and technology developed during SEASAT, SIR-A and SIR-B missions to meet the needs of the Earth Observing System (EOS) in the mid 1990's. As originally formulated, the Project plans were for a reflight of the SIR-B in 1987, the development of a new SAR, SIR-C, for missions in mid 1989 and early 1990, and the upgrade of SIR-C to EOS configuration with a qualification flight aboard the shuttle in the 1993 time frame (SIR-D). However, the loss of the shuttle Challenger has delayed the first manifest for SIR to early 1990. This delay prompted the decision to drop SIR-B reflight plans and move ahead with SIR-C to more effectively utilize this first mission opportunity. The planning for this project is discussed.

  20. Developing tools for digital radar image data evaluation

    NASA Technical Reports Server (NTRS)

    Domik, G.; Leberl, F.; Raggam, J.

    1986-01-01

    The refinement of radar image analysis methods has led to a need for a systems approach to radar image processing software. Developments stimulated through satellite radar are combined with standard image processing techniques to create a user environment to manipulate and analyze airborne and satellite radar images. One aim is to create radar products for the user from the original data to enhance the ease of understanding the contents. The results are called secondary image products and derive from the original digital images. Another aim is to support interactive SAR image analysis. Software methods permit use of a digital height model to create ortho images, synthetic images, stereo-ortho images, radar maps or color combinations of different component products. Efforts are ongoing to integrate individual tools into a combined hardware/software environment for interactive radar image analysis.

  1. SMAP RADAR Processing and Calibration

    NASA Astrophysics Data System (ADS)

    West, R. D.; Jaruwatanadilok, S.; Kwoun, O.; Chaubell, M. J.

    2013-12-01

    The Soil Moisture Active Passive (SMAP) mission uses L-band radar and radiometer measurements to estimate soil moisture with 4% volumetric accuracy at a resolution of 10 km, and freeze-thaw state at a resolution of 1-3 km. Model sensitivities translate the soil moisture accuracy to a radar backscatter accuracy of 1 dB at 3 km resolution and a brightness temperature accuracy of 1.3 K at 40 km resolution. This presentation will describe the level 1 radar processing and calibration challenges and the choices made so far for the algorithms and software implementation. To obtain the desired high spatial resolution the level 1 radar ground processor employs synthetic aperture radar (SAR) imaging techniques. Part of the challenge of the SMAP data processing comes from doing SAR imaging on a conically scanned system with rapidly varying squint angles. The radar echo energy will be divided into range/Doppler bins using time domain processing algorithms that can easily follow the varying squint angle. For SMAP, projected range resolution is about 250 meters, while azimuth resolution varies from 400 meters to 1.2 km. Radiometric calibration of the SMAP radar means measuring, characterizing, and where necessary correcting the gain and noise contributions from every part of the system from the antenna radiation pattern all the way to the ground processing algorithms. The SMAP antenna pattern will be computed using an accurate antenna model, and then validated post-launch using homogeneous external targets such as the Amazon rain forest to look for uncorrected gain variation. Noise subtraction is applied after image processing using measurements from a noise only channel. Variations of the internal electronics are tracked by a loopback measurement which will capture most of the time and temperature variations of the transmit power and receiver gain. Long-term variations of system performance due to component aging will be tracked and corrected using stable external reference targets. Candidate targets include the Amazon rain forest and a model-corrected global ocean measurement. Radio frequency interference (RFI) signals are expected in the L-band frequency window used by the SMAP radar because many other users also operate in this band. Based on results of prior studies at JPL, SMAP L1 radar processing will use a "Slow-time thresholding" or STT algorithm to handle RFI contamination. The STT technique looks at the slow-time series associated with a given range sample, sets an appropriate threshold, and identifies any samples that rise above this threshold as RFI events. The RFI events are removed and the data are azimuth compressed without those samples. Faraday rotation affects L-band signals by rotating the polarization vector during propagation through the ionosphere. This mixes HH, VV, HV, and VH results with each other introducing another source of error. The SMAP radar is not fully polarimetric so the radar data do not provide a correction by themselves. Instead a correction must be derived from other sources. L1 radar processing will use estimates of Faraday rotation derived from externally supplied GPS-based measurements of the ionosphere total electron content (TEC). This work is supported by the SMAP project at the Jet Propulsion Laboratory, California Institute of Technology.

  2. Radar image registration and rectification

    NASA Technical Reports Server (NTRS)

    Naraghi, M.; Stromberg, W. D.

    1983-01-01

    Two techniques for radar image registration and rectification are presented. In the registration method, a general 2-D polynomial transform is defined to accomplish the geometric mapping from one image into the other. The degree and coefficients of the polynomial are obtained using an a priori found tiepoint data set. In the second part of the paper, a rectification procedure is developed that models the distortion present in the radar image in terms of the radar sensor's platform parameters and the topographic variations of the imaged scene. This model, the ephemeris data and the digital topographic data are then used in rectifying the radar image. The two techniques are then used in registering and rectifying two examples of radar imagery. Each method is discussed as to its benefits, shortcomings and registration accuracy.

  3. Method for providing a polarization filter for processing synthetic aperture radar image data

    NASA Technical Reports Server (NTRS)

    Dubois, Pascale C. (Inventor); vanZyl, Jakob J. (Inventor)

    1991-01-01

    A polarization filter can maximize the signal-to-noise ratio of a polarimetric SAR and help discriminate between targets or enhance image features, e.g., enhance contract between different types of target. The method disclosed is based on the Stokes matrix/Stokes vector representation, so the targets of interest can be extended targets, and the method can also be applied to the case of bistatic polarimetric radars.

  4. Imaging Radar for Ecosystem Studies

    NASA Technical Reports Server (NTRS)

    Waring, Richard H.; Way, JoBea; Hunt, E. Raymond J.; Morrissey, Leslie; Ranson, K. Jon; Weishampel, John F.; Oren, Ram; Franklin, Steven E.

    1996-01-01

    Recently a number of satellites have been launched with radar sensors, thus expanding opportunities for global assessment. In this article we focus on the applications of imaging radar, which is a type of sensor that actively generates pulses of microwaves and, in the interval between sending pulses, records the returning signals reflected back to an antenna.

  5. 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.

  6. 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.

  7. Space Radar Image of Chernobyl

    NASA Technical Reports Server (NTRS)

    1994-01-01

    This is an image of the Chernobyl nuclear power plant and its surroundings, centered at 51.17 north latitude and 30.15 west longitude. The image was acquired by the Spaceborne Imaging Radar-C and X-band Synthetic Aperture Radar aboard the space shuttle Endeavour on its 16th orbit on October 1, 1994. The area is located on the northern border of the Ukraine Republic and was produced by using the L-band (horizontally transmitted and received) polarization. The differences in the intensity are due to differences in vegetation cover, with brighter areas being indicative of more vegetation. These data were acquired as part of a collaboration between NASA and the National Space Agency of Ukraine in Remote Sensing and Earth Sciences. NASA has included several sites provided by the Ukrainian space agency as targets of opportunity during the second flight of SIR-C/X-SAR. The Ukrainian space agency also plans to conduct airborne surveys of these sites during the mission. The Chernobyl nuclear power plant is located toward the top of the image near the Pripyat River. The 12-kilometer (7.44-mile)-long cooling pond is easily distinguishable as an elongated dark shape in the center near the top of the image. The reactor complex is visible as the bright area to the extreme left of the cooling pond and the city of Chernobyl is the bright area just below the cooling pond next to the Pripyat River. The large dark area in the bottom right of the image is the Kiev Reservoir just north of Kiev. Also visible is the Dnieper River, which feeds into the Kiev Reservoir from the top of the image. The Soviet government evacuated 116,000 people within 30 kilometers (18.6 miles) of the Chernobyl reactor after the explosion and fire on April 26, 1986. 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 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.

  8. 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 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.

  9. Cognitive processing for nonlinear radar

    NASA Astrophysics Data System (ADS)

    Martone, Anthony; Ranney, Kenneth; Hedden, Abigail; Mazzaro, Gregory; McNamara, David

    2013-05-01

    An increasingly cluttered electromagnetic environment (EME) is a growing problem for radar systems. This problem is becoming critical as the available frequency spectrum shrinks due to growing wireless communication device usage and changing regulations. A possible solution to these problems is cognitive radar, where the cognitive radar learns from the environment and intelligently modifies the transmit waveform. In this paper, a cognitive nonlinear radar processing framework is introduced where the main components of this framework consist of spectrum sensing processing, target detection and classification, and decision making. The emphasis of this paper is to introduce a spectrum sensing processing technique that identifies a transmit-receive frequency pair for nonlinear radar. It will be shown that the proposed technique successfully identifies a transmit-receive frequency pair for nonlinear radar from data collected from the EME.

  10. 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 centered near 37.4 degrees north latitude and 118.3 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 the United States space agencies, is part of NASA's Mission to Planet Earth.

  11. Space Radar Image of Central Sumatra, Indonesia

    NASA Technical Reports Server (NTRS)

    1994-01-01

    This is a radar image of the central part of the island of Sumatra in Indonesia that shows how the tropical rainforest typical of this country is being impacted by human activity. Native forest appears in green in this image, while prominent pink areas represent places where the native forest has been cleared. The large rectangular areas have been cleared for palm oil plantations. The bright pink zones are areas that have been cleared since 1989, while the dark pink zones are areas that were cleared before 1989. These radar data were processed as part of an effort to assist oil and gas companies working in the area to assess the environmental impact of both their drilling operations and the activities of the local population. Radar images are useful in these areas because heavy cloud cover and the persistent smoke and haze associated with deforestation have prevented usable visible-light imagery from being acquired since 1989. The dark shapes in the upper right (northeast) corner of the image are a chain of lakes in flat coastal marshes. This image was acquired in October 1994 by the Spaceborne Imaging Radar C/X-Band Synthetic Aperture Radar (SIR-C/X-SAR) onboard the space shuttle Endeavour. Environmental changes can be easily documented by comparing this image with visible-light data that were acquired in previous years by the Landsat satellite. The image is centered at 0.9 degrees north latitude and 101.3 degrees east longitude. The area shown is 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; green is L-band horizontally transmitted, vertically received; blue is L-band vertically transmitted, vertically 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 program.

  12. Adaptive nonlinear vector filtering of multichannel radar images

    NASA Astrophysics Data System (ADS)

    Lukin, Vladimir V.; Zelensky, Alexander A.; Kurekin, Andrei A.; Astola, Jaakko T.; Saarinen, Kari P.

    1997-09-01

    Here we consider the possibility of applying vector median filtering for joint processing of multichannel radar images. The goal is to correct distortions due errors in superimposing of channels. The proposed approach is a two-stage one. It takes into account the difference between statistical characteristics of images formed by side-look aperture radar (SLAR) and synthetic aperture radar (SAR) and uses the correlation properties of the signal processed by vector filter. Image enhancement is achieved as many false edges are eliminated and contrast of true edges is increased. Filter properties are analyzed both with simulated test images and real radar data.

  13. 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 mission of the German, Italian, and the United States space agencies, is part of NASA's Mission to Planet Earth.

  14. Radar imaging of water surface flow fields

    NASA Astrophysics Data System (ADS)

    Nicolas, K. R.; Lindenmuth, W. T.; Weller, C. S.; Anthony, D. G.

    We describe the capabilities of coherent high resolution radar to observe remotely the effects of an upwelling subsurface flow on the water surface. This observation is possible because the radar radiation backscatters very strongly from surface features with dimensions similar to its wavelength, in this case X-band at 0.03 m. This technique provides imaging capability with relatively high spatial resolution ( 0.3 m) and fast time sampling ( 0.006 s) over a large surface area. The processed data reveal both the line-of-sight velocity spectrum of moving water surface features, and their water surface radar backscatter cross-section. We believe that the surface features are generated by subsurface vortices oriented normal to the surface. The vortices are advected with the bulk flow of the jet. Our radar observations of the down-stream flow from a submerged waterjet that is directed parallel to the surface are consistent with those previously measured by laser velocimetry.

  15. 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.

  16. Earth Penetration Radar Imaging System (EPRIS)

    NASA Astrophysics Data System (ADS)

    1993-08-01

    The Earth Penetration Radar Imaging System (EPRIS) has been developed and has the capability to detect and locate buried mines, buried ordnance delivered by precision munitions, buried drums, buried waste/contaminants, and geological structures/features. The detected objects or features are mapped in three dimensions with high resolution. This information is then available for integration into a site characterization study. The EPRIS is a significant improvement in non-intrusive sensing and imaging capability. This phase of the EPRIS development has been extremely successful. Coleman Research Corporation (CRC) has implemented significant advances in technology into the EPRIS equipment. The frequency stepped radar sensor design has a very wide dynamic signal range and improved sensitivity over currently available equipment. The two- and three-dimensional image processing algorithms allow high-resolution placement and sizing of buried objects and/or features. The discussions related to the analog-to-digital converter and the spiral antenna, define the source of the dynamic range capability realized by EPRIS. The processing for this new radar makes use of unique synthetic aperature imaging (SAI) algorithms developed by CRC for frequency stepped radar systems. The SAI algorithms are necessary to obtain excellent spatial resolution on objects buried up to seven meters. The sensor signal processing represents a significant improvement in imaging systems. The CRC test facility permitted tests on objects buried up to 2.44 meters.

  17. Digital image transformation and rectification of spacecraft and radar images

    USGS Publications Warehouse

    Wu, S.S.C.

    1985-01-01

    Digital image transformation and rectification can be described in three categories: (1) digital rectification of spacecraft pictures on workable stereoplotters; (2) digital correction of radar image geometry; and (3) digital reconstruction of shaded relief maps and perspective views including stereograms. Digital rectification can make high-oblique pictures workable on stereoplotters that would otherwise not accommodate such extreme tilt angles. It also enables panoramic line-scan geometry to be used to compile contour maps with photogrammetric plotters. Rectifications were digitally processed on both Viking Orbiter and Lander pictures of Mars as well as radar images taken by various radar systems. By merging digital terrain data with image data, perspective and three-dimensional views of Olympus Mons and Tithonium Chasma, also of Mars, are reconstructed through digital image processing. ?? 1985.

  18. Triangulation using synthetic aperture radar images

    NASA Technical Reports Server (NTRS)

    Wu, Sherman S. C.; Howington-Kraus, Annie E.

    1991-01-01

    For the extraction of topographic information about Venus from stereoradar images obtained from the Magellan Mission, a Synthetic Aperture Radar (SAR) compilation system was developed on analytical stereoplotters. The system software was extensively tested by using stereoradar images from various spacecraft and airborne radar systems, including Seasat, SIR-B, ERIM XCL, and STAR-1. Stereomodeling from radar images was proven feasible, and development is on a correct approach. During testing, the software was enhanced and modified to obtain more flexibility and better precision. Triangulation software for establishing control points by using SAR images was also developed through a joint effort with the Defense Mapping Agency. The SAR triangulation system comprises four main programs, TRIDATA, MODDATA, TRISAR, and SHEAR. The first two programs are used to sort and update the data; the third program, the main one, performs iterative statistical adjustment; and the fourth program analyzes the results. Also, input are flight data and data from the Global Positioning System and Inertial System (navigation information). The SAR triangulation system was tested with six strips of STAR-1 radar images on a VAX-750 computer. Each strip contains images of 10 minutes flight time (equivalent to a ground distance of 73.5 km); the images cover a ground width of 22.5 km. All images were collected from the same side. With an input of 44 primary control points, 441 ground control points were produced. The adjustment process converged after eight iterations. With a 6-m/pixel resolution of the radar images, the triangulation adjustment has an average standard elevation error of 81 m. Development of Magellan radargrammetry will be continued to convert both SAR compilation and triangulation systems into digital form.

  19. Radar Image of Galapagos Island

    NASA Technical Reports Server (NTRS)

    1994-01-01

    This is an image showing part of Isla Isabella in the western Galapagos Islands. It was taken by the L-band radar in HH polarization from the Spaceborne Imaging Radar C/X-Band Synthetic Aperture Radar on the 40th orbit of the space shuttle Endeavour. The image is centered at about 0.5 degree south latitude and 91 degrees west longitude and covers an area of 75 by 60 kilometers (47 by 37 miles). The radar incidence angle at the center of the image is about 20 degrees.

    The western Galapagos Islands, which lie about 1,200 kilometers (750 miles) west of Ecuador in the eastern Pacific, have six active volcanoes similar to the volcanoes found in Hawaii. Since the time of Charles Darwin's visit to the area in 1835, there have been over 60 recorded eruptions of these volcanoes. This SIR-C/X-SAR image of Alcedo and Sierra Negra volcanoes shows the rougher lava flows as bright features, while ash deposits and smooth pahoehoe lava flows appear dark. A small portion of Isla Fernandina is visible in the extreme upper left corner of the image.

    The Galapagos Islands are one of the SIR-C/X-SAR supersites and data of this area will be taken several times during the flight to allow scientists to conduct topographic change studies and to search for different lava flow types, ash deposits and fault lines.

    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).

  20. Radar imaging with compressed sensing

    NASA Astrophysics Data System (ADS)

    Harding, Brian J.; Milla, Marco

    2013-09-01

    A novel technique for radar-imaging inversions is proposed which leverages ideas from the emerging field of compressed sensing. This new method takes advantage of the transform sparsity inherent in natural images. Theoretical recovery results are promising and are borne out by simulations in which this technique outperforms Capon's method and the Maximum Entropy method. Preliminary results using data collected at the Jicamarca Radio Observatory are also presented.

  1. Space Radar Image of Rocky Mountains, Montana

    NASA Technical Reports Server (NTRS)

    1994-01-01

    This is a three-dimensional perspective of the eastern front range of the Rocky Mountains, about 120 kilometers (75 miles) west of Great Falls, Montana. The image was created by combining two spaceborne radar images using a technique known as interferometry. Visualizations like this are useful to scientists because they show 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 south-southeast. Along the right edge of the image is the valley of the north fork of the Sun River. The western edge of the Great Plains appears on the left side. The valleys in the lower center, running off into the plains on the left, are branches of the Teton River. The highest mountains are at elevations of 2,860 meters (9,390 feet), and the plains are about 1,400 meters (4,500 feet) above sea level. The dark brown areas are grasslands, bright green areas are farms, light brown, orange 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) 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. 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 the differences seen in the L-band data between the two days. This image is centered near 47.7 degrees north latitude and 112.7 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's program entitled Mission to Planet Earth.

  2. Multistatic Radar Imaging of Moving Targets

    E-print Network

    Cheney, Margaret

    Multistatic Radar Imaging of Moving Targets LING WANG, Member, IEEE MARGARET CHENEY, Member, IEEE that in special cases, the theory reduces to: 1) range-Doppler imaging, 2) inverse synthetic aperture radar (ISAR), 3) synthetic aperture radar (SAR), 4) Doppler SAR, and 5) tomography of moving targets. Manuscript

  3. Optical fiber imaging laser radar

    NASA Astrophysics Data System (ADS)

    Akiyama, Akira; Watanabe, Takahiro; Doshida, Minoru; Kanda, Kazuhisa; Kakimoto, Yukiteru; Yasuo, Hiroyuki; Kuwabara, Masahiro; Kumagai, Hideo; Ishii, Hiromitsu

    2003-11-01

    We have developed the Optical Fiber Imaging Laser Radar based on the focal plane array detection using the small number of detectors less than the number of the focal plane array resolution. For this focal array detection, first, we made the optical fiber dissector which has one vertical cross section of the 35 x 35 optical fibers square array at one end to receive the reflected laser pulse from an object and 25 vertical cross sections of the 7 x 7 optical fibers array extracted from the 35 x 35 optical fibers square array at 25 other ends to guide the dissected laser pulse to the 25 InGaAs photodiode pulse detectors of the 25 channels of the parallel pulse counter. The 7 x 7 optical fibers arrays are the mode (5,5) residual classes from the 35 x 35 optical fibers square array. Second, we shaped the most of Erbium doped optical fiber laser pulse into the laser pulse with the beam of the elliptic cross section that falls into one 5 x 5 area of the vertical cross section of the 35 x 35 optical fibers square array when it is received. And we made a mask with a window of a size 5 x 5 optical fibers" cross section to ensure no cross talk in the receiver of the Optical Fiber Imaging Laser Radar. Then, we controlled the direction of the shaped laser pulse to scan and reconstruct the received data from the 25 channels of the parallel pulse counter to the actual order data of the Imaging Laser Radar. The developed Imaging Laser Radar shows that the image resolution between the range image and the object is within one pixel difference and that the range resolution is under 15cm.

  4. 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 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.

  5. Space Radar Image of Oil Slicks

    NASA Technical Reports Server (NTRS)

    1994-01-01

    This is a radar image of an offshore drilling field about 150 km (93 miles) west of Bombay, India, in the Arabian Sea. The dark streaks are extensive oil slicks surrounding many of the drilling platforms, which appear as bright white spots. Radar images are useful for detecting and measuring the extent of oil seepages on the ocean surface, from both natural and industrial sources. The long, thin streaks extending from many of the platforms are spreading across the sea surface, pushed by local winds. The larger dark patches are dispersed slicks that were likely discharged earlier than the longer streaks, when the winds were probably from a different direction. The dispersed oil will eventually spread out over the more dense water and become a layer which is a single molecule thick. Many forms of oil, both from biological and from petroleum sources, smooth out the ocean surface, causing the area to appear dark in radar images. There are also two forms of ocean waves shown in this image. The dominant group of large waves (upper center) are called internal waves. These waves are formed below the ocean surface at the boundary between layers of warm and cold water and they appear in the radar image because of the way they change the ocean surface. Ocean swells, which are waves generated by winds, are shown throughout the image but are most distinct in the blue area adjacent to the internal waves. Identification of waves provide oceanographers with information about the smaller scale dynamic processes of the ocean. 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 9, 1994. The colors are assigned to different frequencies and polarizations of the radar as follows: Red is L-band vertically transmitted, vertically received; green is the average of L-band vertically transmitted, vertically received and C-band vertically transmitted, vertically received; blue is C-band vertically transmitted, vertically received. The image is located at 19.25 degrees north latitude and 71.34 degrees east longitude and covers an area 20 km by 45 km (12.4 miles by 27.9 miles). 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.

  6. Radar image San Francisco Bay Area, California

    NASA Technical Reports Server (NTRS)

    2000-01-01

    The San Francisco Bay Area in California and its surroundings are shown in this radar image from the Shuttle Radar Topography Mission (SRTM). On this image, smooth areas, such as the bay, lakes, roads and airport runways appear dark, while areas with buildings and trees appear bright. Downtown San Francisco is at the center and the city of Oakland is at the right across the San Francisco Bay. Some city areas, such as the South of Market district in San Francisco, appear bright due to the alignment of streets and buildings with respect to the incoming radar beam. Three of the bridges spanning the Bay are seen in this image. The Bay Bridge is in the center and extends from the city of San Francisco to Yerba Buena and Treasure Islands, and from there to Oakland. The Golden Gate Bridge is to the left and extends from San Francisco to Sausalito. The Richmond-San Rafael Bridge is in the upper right and extends from San Rafael to Richmond. Angel Island is the large island east of the Golden Gate Bridge, and lies north of the much smaller Alcatraz Island. The Alameda Naval Air Station is seen just below the Bay Bridge at the center of the image. Two major faults bounding the San Francisco-Oakland urban areas are visible on this image. The San Andreas fault, on the San Francisco peninsula, is seen on the left side of the image. The fault trace is the straight feature filled with linear reservoirs, which appear dark. The Hayward fault is the straight feature on the right side of the image between the urban areas and the hillier terrain to the east.

    This radar 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 overall faint striping pattern in the images is a data processing artifact due to the 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

  7. A Through-Dielectric Radar Imaging System

    E-print Network

    Charvat, Gregory L.

    Through-lossy-slab radar imaging will be shown at stand-off ranges using a low-power, ultrawideband (UWB), frequency modulated continuous wave (FMCW) radar system. FMCW is desirable for through-slab applications because ...

  8. Space Radar Image of Missouri River - TOPSAR

    NASA Technical Reports Server (NTRS)

    1999-01-01

    This is a combined radar and topography image of an area along the Missouri River that experienced severe flooding and levee failure in the summer of 1993. The meandering course of the Missouri River is seen as the dark curving band on the left side of the image. The predominantly blue area on the left half of the image is the river's floodplain, which was completely inundated during the flood of 1993. The colors in the image represent elevations, with the low areas shown in purple, intermediate areas in blue, green and yellow, and the highest areas shown in orange. The total elevation range is 85 meters (279 feet). The higher yellow and orange area on the right side of the image shows the topography and drainage patterns typical of this part of the midwestern United States. Dark streaks and bands in the floodplain are agricultural areas that were severely damaged by levee failures during the flooding. The region enclosed by the C-shaped bend in the river in the upper part of the image is Lisbon Bottoms. A powerful outburst of water from a failed levee on the north side of Lisbon Bottoms scoured a deep channel across the fields, which shows up as purple band. As the flood waters receded, deposits of sand and silt were left behind, which now appear as dark, smooth streaks in the image. The yellow areas within the blue, near the river, are clumps of trees sitting on slightly higher ground within the floodplain. The radar 'sees' the treetops, and that is why they are so much higher (yellow) than the fields. The image was acquired by the NASA/JPL Topographic Synthetic Aperture Radar system (TOPSAR) that flew over the area aboard a DC-8 aircraft in August 1994. The elevations are obtained by a technique known as radar interferometry, in which the radar signals are transmitted by one antenna, and echoes are received by two antennas aboard the aircraft. The two sets of received signals are combined using computer processing to produce a topographic map. Similar techniques can be used to map the Earth's topography from satellites and from the space shuttle. The brightness of the image represents the radar backscatter at C-band, in the vertically transmitted and received polarization. The image is centered south of the town of Glasgow in central Missouri, at 39.1 degrees north latitude and 92.9 degrees west longitude. The area shown is about 5 km by 10 km (3.1 by 6.2 miles). Radar and topography data such as these are being used by scientists to more accurately assess the potential for future flooding in this region and how that might impact surrounding communities. Radar and interferometry processing for this image was performed at JPL; image generation was performed at Washington University, St. Louis.

  9. Space Radar Image of Glascow, Missouri

    NASA Technical Reports Server (NTRS)

    1994-01-01

    This is a false-color L-band image of an area near Glasgow, Missouri, centered at about 39.2 degrees north latitude and 92.8 degrees west longitude. The image was acquired using the L-band radar channel (horizontally transmitted and received and horizontally transmitted/vertically received) polarizations combined. The data were acquired by the Spaceborne Imaging Radar-C and X-band Synthetic Aperture Radar (SIR-C/X-SAR) aboard the space shuttle Endeavour on orbit 50 on October 3,1994. The area shown is approximately 37 kilometers by 25 kilometers (23 miles by 16 miles). The radar data, coupled with pre-flood aerial photography and satellite data and post-flood topographic and field data, are being used to evaluate changes associated with levee breaks in landforms, where deposits formed during the widespread flooding in 1993 along the Missouri and Mississippi Rivers. The distinct radar scattering properties of farmland, sand fields and scoured areas will be used to inventory floodplains along the Missouri River and determine the processes by which these areas return to preflood conditions. The image shows one such levee break near Glasgow, Missouri. In the upper center of the radar image, below the bend of the river, is a region covered by several meters of sand, shown as dark regions. West (left) of the dark areas, a gap in the levee tree canopy shows the area where the levee failed. Radar data such as these can help scientists more accurately assess the potential for future flooding in this region and how that might impact surrounding communities. 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 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.

  10. A model for radar images and its application to adaptive digital filtering of multiplicative noise

    NASA Technical Reports Server (NTRS)

    Frost, V. S.; Stiles, J. A.; Shanmugan, K. S.; Holtzman, J. C.

    1982-01-01

    Standard image processing techniques which are used to enhance noncoherent optically produced images are not applicable to radar images due to the coherent nature of the radar imaging process. A model for the radar imaging process is derived in this paper and a method for smoothing noisy radar images is also presented. The imaging model shows that the radar image is corrupted by multiplicative noise. The model leads to the functional form of an optimum (minimum MSE) filter for smoothing radar images. By using locally estimated parameter values the filter is made adaptive so that it provides minimum MSE estimates inside homogeneous areas of an image while preserving the edge structure. It is shown that the filter can be easily implemented in the spatial domain and is computationally efficient. The performance of the adaptive filter is compared (qualitatively and quantitatively) with several standard filters using real and simulated radar images.

  11. 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 radar missions to help in better understanding the processes responsible for volcanic eruptions and earthquakes. 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 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.

  12. Improving Ground Penetrating Radar Imaging in High Loss Environments by Coordinated System Development, Data Processing, Numerical Modeling, & Visualization ...

    SciTech Connect

    Powers, Michael H.

    2003-06-01

    The Department of Energy has identified the location and characterization of subsurface contaminants and the characterization of the subsurface as a priority need. Many DOE facilities are in need of subsurface imaging in the vadose and saturated zones. This includes (1) the detection and characterization of metal and concrete structures, (2) the characterization of waste pits (for both contents and integrity) and (3) mapping the complex geological/hydrological framework of the vadose and saturated zones. The DOE has identified ground penetrating radar (GPR) as a method that can non-invasively map transportation pathways and vadose zone heterogeneity. An advanced GPR system and advanced subsurface modeling, processing, imaging, and inversion techniques can be directly applied to several DOE science needs in more than one focus area and at many sites. Needs for enhanced subsurface imaging have been identified at Hanford, INEEL, SRS, ORNL, LLNL, SNL, LANL, and many other sites. In fact, needs for better subsurface imaging probably exist at all DOE sites. However, GPR performance is often inadequate due to increased attenuation and dispersion when soil conductivities are high. Our objective is to extend the limits of performance of GPR by improvements to both hardware and numerical computation. The key features include (1) greater dynamic range through real time digitizing, receiver gain improvements, and high output pulser, (2) modified, fully characterized antennas with sensors to allow dynamic determination of the changing radiated waveform, (3) modified deconvolution and depth migration algorithms exploiting the new antenna output information, (4) development of automatic full waveform inversion made possible by the known radiated pulse shape.

  13. 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.

  14. Space Radar Image of Bahia

    NASA Technical Reports Server (NTRS)

    1994-01-01

    This is a color composite image of southern Bahia, Brazil, centered at 15.22 degree south latitude and 39.07 degrees west longitude. The image was acquired by the Spaceborne Imaging Radar-C/X-band Synthetic Aperture Radar aboard the space shuttle Endeavour on its 38th orbit of Earth on October 2, 1994. The image covers an area centered over the Una Biological Reserve, one the largest protected areas in northeastern Brazil. The 7,000-hectare reserve is administered by the Brazilian Institute for the Environment and is part of the larger Atlantic coastal forest, a narrow band of rain forest extending along the eastern coast of Brazil. The Atlantic coastal forest of southern Bahia is one of the world's most threatened and diverse ecosystems. Due to widespread settlement, only 2 to 5 percent of the original forest cover remains. Yet the region still contains an astounding variety of plants and animals, including a large number of endemic species. More than half of the region's tree species and 80 percent of its animal species are indigenous and found nowhere else on Earth. The Una Reserve is also the only federally protected habitat for the golden-headed lion tamarin, the yellow-breasted capuchin monkey and many other endangered species. In the past few years, scientists from Brazilian and international conservation organizations have coordinated efforts to study the biological diversity of this region and to develop practical and economically viable options for preserving the remaining primary forests in southern Bahia. The shuttle imaging radar is used in this study to identify various land uses and vegetation types, including remaining patches of primary forest, cabruca forest (cacao planted in the understory of the native forest), secondary forest, pasture and coastal mangrove. Standard remote-sensing technology that relies on light reflected from the forest canopy cannot accurately distinguish between cabruca and undisturbed forest. Optical remote sensing is also 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. The radars illuminate Earth with microwaves, allowing detailed observations at any time, rega

  15. 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 visible in the radar image; many of them can also be seen as bright lines i the optical image. The runways of John F. Kennedy International Airport appear as a dark rectangle in Jamaica Bay on the left side of the image. Developed areas appear generally as bright green and orange, while agricultural, protected and undeveloped areas appear darker blue or purple. This contrast can be seen on the barrier islands along the south coast of Long Island, which are heavily developed in the Rockaway and Long Beach areas south and east of Jamaica Bay, but further to the east, the islands are protected and undeveloped.

  16. Applications review for a Space Program Imaging Radar (SPIR)

    NASA Technical Reports Server (NTRS)

    Simonett, D. S.

    1976-01-01

    The needs, applications, user support, research, and theoretical studies of imaging radar are reviewed. The applications of radar in water resources, minerals and petroleum exploration, vegetation resources, ocean radar imaging, and cartography are discussed. The advantages of space imaging radar are presented, and it is recommended that imaging radar be placed on the space shuttle.

  17. Space Radar Image of Kiluchevskoi, Volcano, Russia

    NASA Technical Reports Server (NTRS)

    1994-01-01

    This is an image of the area of Kliuchevskoi volcano, Kamchatka, Russia, which began to erupt on September 30, 1994. Kliuchevskoi is the blue triangular peak in the center of the image, towards the left edge of the bright red area that delineates bare snow cover. 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 88th orbit on October 5, 1994. The image shows an area approximately 75 kilometers by 100 kilometers (46 miles by 62 miles) that is centered at 56.07 degrees north latitude and 160.84 degrees east longitude. North is toward the bottom of the image. The radar illumination is from the top of the image. The Kamchatka volcanoes are among the most active volcanoes in the world. The volcanic zone sits above a tectonic plate boundary, where the Pacific plate is sinking beneath the northeast edge of the Eurasian plate. The Endeavour crew obtained dramatic video and photographic images of this region during the eruption, which will assist scientists in analyzing the dynamics of the recent activity. 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 and vertically received); blue represents the C-band (horizontally transmitted and vertically received). In addition to Kliuchevskoi, two other active volcanoes are visible in the image. Bezymianny, the circular crater above and to the right of Kliuchevskoi, contains a slowly growing lava dome. Tolbachik is the large volcano with a dark summit crater near the upper right edge of the red snow covered area. The Kamchatka River runs from right to left across the bottom of the image. The current eruption of Kliuchevskoi included massive ejections of gas, vapor and ash, which reached altitudes of 15,000 meters (50,000 feet). Melting snow mixed with volcanic ash triggered mud flows on the flanks of the volcano. Paths of these flows can be seen as thin lines in various shades of blue and green on the north flank in the center of the 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 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.

  18. 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-C/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 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.

  19. Radar image processing of real aperture SLAR data for the detection and identification of iceberg and ship targets

    NASA Technical Reports Server (NTRS)

    Marthaler, J. G.; Heighway, J. E.

    1979-01-01

    An iceberg detection and identification system consisting of a moderate resolution Side Looking Airborne Radar (SLAR) interfaced with a Radar Image Processor (RIP) based on a ROLM 1664 computer with a 32K core memory updatable to 64K is described. The system can be operated in high- or low-resolution sampling modes. Specifically designed algorithms are applied to digitized signal returns to provide automatic target detection and location, geometrically correct video image display and data recording. The real aperture Motorola AN/APS-94D SLAR operates in the X-band and is tunable between 9.10 and 9.40 GHz; its output power is 45 kW peak with a pulse repetition rate of 750 pulses per hour. Schematic diagrams of the system are provided, together with preliminary test data.

  20. Optical fiber imaging laser radar

    NASA Astrophysics Data System (ADS)

    Akiyama, Akira; Kakimoto, Yukiteru; Kanda, Kazuhisa; Kuwabara, Masahiro; Yasuo, Hiroyuki; Mutoh, Eiichiro; Kumagai, Hideo; Watanabe, Takahiro; Doshida, Minoru; Ishii, Hiromitsu

    2005-01-01

    We develop an optical fiber imaging laser radar based on the focal plane array detection method using a small number of detectors less than the number of the focal plane array resolution. For the development of this kind of the focal array detection method, we produce the optical fiber dissector, the movable aperture, and the small-number parallel multichannel pulse counter receiver. The optical fiber dissector has one vertical cross section of the 35×35 optical fiber square array for the focal plane at one end and 25 vertical cross sections of the 25 optical fiber bundles for the 25-channel parallel multichannel pulse counter receiver at the other end. Each optical fiber bundle has the 49 optical fibers selected from the 35×35 optical fiber square array with no overlap. The movable aperture has a window of a size 5×5 optical fiber cross section to ensure no crosstalk for the detection of the divergent pulse laser beam. The divergent pulse laser beam is focused on some 5×5 area of the 35×35 optical fiber square array related to its scanning direction. The developed optical fiber imaging laser radar shows high range resolution and no-crosstalk angle resolution. The range resolution is under 15 cm. The angle resolution is 1 pixel.

  1. The Second Spaceborne Imaging Radar Symposium

    NASA Technical Reports Server (NTRS)

    1986-01-01

    Summaries of the papers presented at the Second Spaceborne Imaging Radar Symposium are presented. The purpose of the symposium was to present an overwiew of recent developments in the different scientific and technological fields related to spaceborne imaging radars and to present future international plans.

  2. SMAP Radar Processing and Calibration

    NASA Technical Reports Server (NTRS)

    West, R.; Jaruwatanadilok, S.; Kwoun, O.; Chaubell, M.

    2013-01-01

    The Soil Moisture Active Passive (SMAP) mission is part of the NASA space-based Earth observation program, and consists of an L-band radar and radiometer scheduled for launch into sun synchronous orbit in late 2014. A joint effort of the Jet Propulsion Laboratory (JPL) and the Goddard Space Flight Center (GSFC), the SMAP mission draws heavily on the design and risk reduction heritage of the Hydrosphere State (Hydros) mission [1], [2]. The SMAP science and applications objectives are to: 1) understand processes that link the terrestrial water, energy and carbon cycles, 2) estimate global water and energy fluxes at the land surface, 3) quantify net carbon flux in boreal landscapes, 4) enhance weather and climate forecast skill, and 5) develop improved flood prediction and drought monitoring capability. To meet these science objectives, SMAP ground processing will combine the attributes of the radar and radiometer observations (in terms of their spatial resolution and sensitivity to soil moisture, surface roughness, and vegetation) to estimate soil moisture with 4% volumetric accuracy at a resolution of 10 km, and freeze-thaw state at a resolution of 1-3 km. Model sensitivities translate the soil moisture accuracy to a radar backscatter accuracy of 1 dB (1 sigma) at 3 km resolution and a brightness temperature accuracy of 1.3 K at 40 km resolution. This paper will describe the level 1 radar processing and calibration challenges and the choices made so far for the algorithms and software implementation.

  3. Spaceborne Imaging Radar-C instrument

    NASA Technical Reports Server (NTRS)

    Huneycutt, Bryan L.

    1993-01-01

    The Spaceborne Imaging Radar-C is the next radar in the series of spaceborne radar experiments, which began with Seasat and continued with SIR-A and SIR-B. The SIR-C instrument has been designed to obtain simultaneous multifrequency and simultaneous multipolarization radar images from a low earth orbit. It is a multiparameter imaging radar that will be flown during at least two different seasons. The instrument operates in the squint alignment mode, the extended aperture mode, the scansar mode, and the interferometry mode. The instrument uses engineering techniques such as beam nulling for echo tracking, pulse repetition frequency hopping for Doppler centroid tracking, generating the frequency step chirp for radar parameter flexibility, block floating-point quantizing for data rate compression, and elevation beamwidth broadening for increasing the swath illumination.

  4. Space Radar Image of North Sea, Germany

    NASA Technical Reports Server (NTRS)

    1994-01-01

    This is an X-band image of an oil slick experiment conducted in the North Sea, Germany. The image is centered at 54.58 degrees north latitude and 7.48 degrees east longitude. 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 October 6, 1994, during the second flight of the spaceborne radar. The experiment was designed to differentiate between petroleum oil spills and natural slicks floating on the sea surface. Two types of petroleum oil and six types of oils resembling natural sea surface slicks were poured on the sea surface from ships and a helicopter just before the space shuttle flew over the region. At the bottom of the image is the Sylt peninsula, a famous holiday resort. Twenty-six gallons (100 liters) of diesel oil was dissipated due to wave action before the shuttle reached the site. The oil spill seen at the uppermost part of the image is about 105 gallons (400 liters) of heavy heating oil and the largest spill is about 58 gallons (220 liters) of oleyl alcohol, resembling a 'natural oil' like the remaining five spills used to imitate natural slicks that have occurred offshore from various states. The volume of these other oils spilled on the ocean surface during the five experimental spills varied from 16 gallons to 21 gallons (60 liters to 80 liters). The distance between neighboring spills was about half a mile (800 meters) at the most. The largest slick later thinned out to monomolecular sheets of about 10 microns, which is the dimension of a molecule. Oceanographers found that SIR-C/X-SAR was able to clearly distinguish the oil slicks from algae products dumped nearby. Preliminary indications are that various types of slicks may be distinguished, especially when other radar wavelengths are included in the analysis. Radar imaging of the world's oceans on a continuing basis may allow oceanographers in the future to detect and clean up oil spills much more swiftly than is currently possible. 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 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.

  5. Iterative synthetic aperture radar imaging algorithms 

    E-print Network

    Kelly, Shaun Innes

    2014-06-30

    Synthetic aperture radar is an important tool in a wide range of civilian and military imaging applications. This is primarily due to its ability to image in all weather conditions, during both the day and the night, ...

  6. Space Radar Image of Manaus, Brazil

    NASA Technical Reports Server (NTRS)

    1994-01-01

    These two false-color images of the Manaus region of Brazil in South America were acquired by the Spaceborne Imaging Radar-C and X-band Synthetic Aperture Radar on board the space shuttle Endeavour. The image at left was acquired on April 12, 1994, and the image at right was acquired on October 3, 1994. The area shown is approximately 8 kilometers by 40 kilometers (5 miles by 25 miles). The two large rivers in this image, the Rio Negro (at top) and the Rio Solimoes (at bottom), combine at Manaus (west of the image) to form the Amazon River. The image is centered at about 3 degrees south latitude and 61 degrees west longitude. North is toward the top left of the images. The false colors were created by displaying three L-band polarization channels: red areas correspond to high backscatter, horizontally transmitted and received, while green areas correspond to high backscatter, horizontally transmitted and vertically received. Blue areas show low returns at vertical transmit/receive polarization; hence the bright blue colors of the smooth river surfaces can be seen. Using this color scheme, green areas in the image are heavily forested, while blue areas are either cleared forest or open water. The yellow and red areas are flooded forest or floating meadows. The extent of the flooding is much greater in the April image than in the October image and appears to follow the 10-meter (33-foot) annual rise and fall of the Amazon River. The flooded forest is a vital habitat for fish, and floating meadows are an important source of atmospheric methane. These images demonstrate the capability of SIR-C/X-SAR to study important environmental changes that are impossible to see with optical sensors over regions such as the Amazon, where frequent cloud cover and dense forest canopies block monitoring of flooding. Field studies by boat, on foot and in low-flying aircraft by the University of California at Santa Barbara, in collaboration with Brazil's Instituto Nacional de Pesguisas Estaciais, during the first and second flights of the SIR-C/X-SAR system have validated the interpretation of the radar images. 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 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.

  7. High-resolution three-dimensional imaging radar

    NASA Technical Reports Server (NTRS)

    Cooper, Ken B. (Inventor); Chattopadhyay, Goutam (Inventor); Siegel, Peter H. (Inventor); Dengler, Robert J. (Inventor); Schlecht, Erich T. (Inventor); Mehdi, Imran (Inventor); Skalare, Anders J. (Inventor)

    2010-01-01

    A three-dimensional imaging radar operating at high frequency e.g., 670 GHz, is disclosed. The active target illumination inherent in radar solves the problem of low signal power and narrow-band detection by using submillimeter heterodyne mixer receivers. A submillimeter imaging radar may use low phase-noise synthesizers and a fast chirper to generate a frequency-modulated continuous-wave (FMCW) waveform. Three-dimensional images are generated through range information derived for each pixel scanned over a target. A peak finding algorithm may be used in processing for each pixel to differentiate material layers of the target. Improved focusing is achieved through a compensation signal sampled from a point source calibration target and applied to received signals from active targets prior to FFT-based range compression to extract and display high-resolution target images. Such an imaging radar has particular application in detecting concealed weapons or contraband.

  8. Department of Electrical and Computer Engineering Carnegie Mellon University 18793: Optical Image and Radar Processing

    E-print Network

    Casasent, David

    Department of Electrical and Computer Engineering Carnegie Mellon University 18­793: Optical Image://blackboard.andrew.cmu.edu/courses/1/S06­18793 Text: J.W. Goodman, Introduction to Fourier Optics, McGraw­Hill, Second Ed. 1996 Reserve Books: J. Gaskill, Linear Systems, FTs, and Optics R. Collier, L. Lin and C. Burckhardt, Optical

  9. Space Radar Image of Kliuchevskoi, Russia

    NASA Technical Reports Server (NTRS)

    1994-01-01

    This is an X-band seasonal image of the Maly Semlyachik volcano, which is part of the Karymsky volcano group on Kamchatka peninsula, Russia. The image is centered at 54.2 degrees north latitude and 159.6 degrees east longitude. 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 April 9, 1994, during the first flight of the radar system, and on September 30, 1994, during the second flight. The image channels have been assigned the following colors: red corresponds to data acquired on April 9; green corresponds to data acquired on September 30; and blue corresponds to the ratio between data from April 9 and September 30, 1994. Kamchatka is twice as large as England, Scotland and Wales combined and is home to approximately 470,000 residents. The region is characterized by a chain of volcanoes stretching 800 kilometers (500 miles) across the countryside. Many of the volcanoes, including the active Maly Semlyachik volcano in this image, have erupted during this century. But the most active period in creating the three characteristic craters of this volcano goes back 20,000, 12,000 and 2,000 years ago. The highest summit of the oldest crater reaches about 1,560 meters (1,650 feet). The radar images reveal the geological structures of craters and lava flows in order to improve scientists' knowledge of these sometimes vigorously active volcanoes. This seasonal composite also highlights the ecological differences that have occurred between April and October 1994. In April the whole area was snow-covered and, at the coast, an ice sheet extended approximately 5 kilometers (3 miles) into the sea. The area shown surrounding the volcano is covered by low vegetation much like scrub. Kamchatka also has extensive forests, which belong to the northern frontier of Taiga, the boreal forest ecosystem. This region plays an important role in the world's carbon cycle. Trees require 60 years to 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.

  10. Topography from single radar images.

    PubMed

    Wildey, R L

    1984-04-13

    A mathematical theory and a corresponding numerical procedure have been developed to produce digital topography from radar images as digital photometric arrays. Thus, as radargrammetry is to photogrammetry, so radarclinometry is to photoclinometry. Photoclinometry encompasses a fundamental indeterminacy principle even for terrain that is homogeneous in normal albedo, because the surface normal consistent with a given reflected specific intensity is not unique. A geometric locus of such normal directions is implied, which generates a surface. For microwave backscatter, in specific application to radarclinometry, this surface is a cone whose half-angle is the incidence angle, whose axis contains the radar, and whose apex coincides with the terrain point. Although the indeterminacy can be removed if a properly directed profile of ground truth is available as a constraint, such is seldom the case. In its absence, an auxiliary assumption, such as that the strike line runs perpendicular to the illumination line, is needed. If metric integrity is a goal, then this is an absurd assumption. Herein, "the hypothesis of local cylindricity" has been assumed, a premise regarding the nature of topographic curvature that seems more realistic and that makes possible the production of topography as a set of parallel line integrals. PMID:17744680

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

    NASA Technical Reports Server (NTRS)

    Arens, W. E. (inventor)

    1977-01-01

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

  12. Space Radar Image of Oberpfaffenhofen, Germany

    NASA Technical Reports Server (NTRS)

    1999-01-01

    This is a false-color, three-frequency image of the Oberpfaffenhofen supersite, southwest of Munich in southern Germany, which shows the differences in what the three radar bands can see on the ground. The image covers a 27- by 36-kilometer (17- by 22-mile) area. The center of the site is 48.09 degrees north and 11.29 degrees east. The image was acquired by the Spaceborne Imaging Radar C/X-Band Synthetic Aperture Radar (SIR-C/X-SAR) onboard space shuttle Endeavour on April 13, 1994, just after a heavy storm which covered the all area with 20 centimeters (8 inches) of snow. The dark area in the center of the image is Lake Ammersee. The two smaller lakes above the Ammersee are the Worthsee and the Pilsensee. On the right of the image is the tip of the Starnbergersee. The outskirt of the city of Munich can be seen at the top of the image. The Oberpfaffenhofen supersite is the major test site for X-SAR calibration and scientific experiments such as ecology, hydrology and geology. This color composite image is a three-frequency overlay. L-band total power was assigned red, the C-band total power is shown in green and the X-band VV polarization appears blue. The colors on the image stress the differences between the L-band, C-band and X-band images. If the three frequencies were seeing the same thing, the image will appear in black and white. For example, the blue areas corresponds to area for which the X-band backscatter is relatively higher than the backscatter at L-and C-band; this behavior is characteristic of clear cuts or shorter vegetation. Similarly, the forested areas have a reddish tint. Finally, the green areas seen at the southern tip of both the Ammersee and the Pilsensee lakes indicate a marshy 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 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.

  13. Space Radar Image of Baikal Lake, Russia

    NASA Technical Reports Server (NTRS)

    1994-01-01

    This is an X-band black-and-white image of the forests east of the Baikal Forest in the Jablonowy Mountains of Russia. The image is centered at 52.5 degrees north latitude and 116 degrees east longitude near the mining town of Bukatschatscha. This image was acquired by the Spaceborne Imaging Radar-C/X-band Synthetic Aperture Radar aboard the space shuttle Endeavour on October 4, 1994, during the second flight of the spaceborne radar. This area is part of an international research project known as the Taiga Aerospace Investigation using Geographic Information System Applications.

  14. Space Radar Image of Altona, Manitoba, Canada

    NASA Technical Reports Server (NTRS)

    1994-01-01

    This is an X-band seasonal image of the Altona test site in Manitoba, Canada, about 80 kilometers (50 miles) south of Winnipeg. The image is centered at approximately 49 degrees north latitude and 97.5 degrees west longitude. 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 April 11, 1994, during the first flight of the radar system, and on October 2, 1994, during the second flight of SIR-C/X-SAR. The image channels have the following color assignments: red represents data acquired on April 11, 1994; green represents data acquired on October 2, 1994; blue represents the ratio of the two data sets. The test site is located in the Red River Basin and is characterized by rich farmland where a variety of crops are grown, including wheat, barley, canola, corn, sunflowers and sugar beets. This SIR-C/X-SAR research site is applying radar remote sensing to study the characteristics of vegetation and soil moisture. The seasonal comparison between the April and October 1994 data show the dramatic differences between surface conditions on the two dates. At the time of the April acquisition, almost all agricultural fields were bare and soil moisture levels were high. In October, however, soils were drier and while most crops had been harvested, some standing vegetation was still present. The areas which are cyan in color are dark in April and bright in October. These represent fields of standing biomass (amount of vegetation in a specified area) and the differences in brightness within these cyan fields represent differences in vegetation type. The very bright fields in October represent standing broadleaf crops such as corn, which had not yet been harvested. Other standing vegetation which has less biomass, such as hay and grain fields, are less bright. The magenta indicates bare soil surfaces which were wetter (brighter) in April than in October. The variations in brightness of the magenta indicate differences in the degree of soil moisture change and differences in surface roughness. This seasonal composite demonstrates the sensitivity of radar to changes in agricultural surface conditions such as soil moisture, tillage, cropping and harvesting. 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 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.

  15. 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 States space agencies, is part of NASA's Mission to Planet Earth.

  16. 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.

  17. Airborne ground penetrating imaging radar operating at L-band

    NASA Astrophysics Data System (ADS)

    Gordy, Robert S.; Markell, David P.

    2010-04-01

    The FOPEN radar was designed and fabricated in response to the need to detect items buried below the surface using a rapid detection method from an airborne platform. The system uses Synthetic Aperture Radar Processing in the form of ratcheting spot light SAR. The image of the ground at a slant range of 40 degrees on either the right or left side of the aircraft and gives a two dimensional image of the ground. The antenna can also point in a nadir position to sound the ground. The radar was developed to image 1 sq mile with each frame with a resolution of 1 meter in the slant range. This requires the use of the entire L-Band radar spectrum of 150 Meg Hz. In order to detect images below the ground additional processing must be performed on the raw data, accordingly the raw data is recorded at a data rate of 200 Mbyte/second. The data is recorded as both I and Q data. The radar has on board processing but only for verifying that the system is operating. Not all adjacent frames are processed for this reason. The processing and analysis is performed on the ground by a system that has multiple work stations and software to process the image of the surface and the sub surface. By further processing the data the surface can be removed and the lower level glint points can be seen and enhanced using signal processing techniques.

  18. Signal processing techniques for stepped frequency ultra-wideband radar

    NASA Astrophysics Data System (ADS)

    Nguyen, Lam

    2014-05-01

    The U.S. Army Research Laboratory (ARL) has developed the impulse-based, ground vehicle-based, forward-looking ultra-wideband (UWB), synthetic aperture radar (SAR) to detect concealed targets. Although the impulse-based architecture offers its own advantages, one of the important challenges is that when using this architecture it is very difficult to transmit a radar signal with an arbitrary bandwidth and shape. This feature is crucial for the radar to be compliant with the local frequency authority. In addition, being able to transmit signals with an arbitrary spectral shape is an important step in creating the next generation of smart (cognitive) radars. Therefore, we have designed a next-generation prototype radar to take advantage of the stepped frequency architecture. The design and building of the radar hardware is underway. In this paper, we study the radar transmit and acquisition scheme; the trade-offs between SAR image performance and various key radar parameters; and data reconstruction techniques for radar signals with an arbitrary spectrum. This study demonstrates performance, provides some guidelines for the radar design, and serves as a foundation for the signal and image processing stage.

  19. Space Radar Image of Karisoke & Virunga Volcanoes

    NASA Technical Reports Server (NTRS)

    1994-01-01

    This is a false-color composite of Central Africa, showing the Virunga volcano chain along the borders of Rwanda, Zaire and Uganda. This area is home to the endangered mountain gorillas. The image was acquired on October 3, 1994, on orbit 58 of the space shuttle Endeavour by the Spaceborne Imaging Radar-C/X-band Synthetic Aperture Radar (SIR-C/X-SAR). In this image red is the L-band (horizontally transmitted, vertically received) polarization; green is the C-band (horizontally transmitted and received) polarization; and blue is the C-band (horizontally transmitted and received) polarization. The area is centered at about 2.4 degrees south latitude and 30.8 degrees east longitude. The image covers an area 56 kilometers by 70 kilometers (35 miles by 43 miles). The dark area at the top of the image is Lake Kivu, which forms the border between Zaire (to the right) and Rwanda (to the left). In the center of the image is the steep cone of Nyiragongo volcano, rising 3,465 meters (11,369 feet) high, with its central crater now occupied by a lava lake. To the left are three volcanoes, Mount Karisimbi, rising 4,500 meters (14,800 feet) high; Mount Sabinyo, rising 3,600 meters (12,000 feet) high; and Mount Muhavura, rising 4,100 meters (13,500 feet) high. To their right is Nyamuragira volcano, which is 3,053 meters (10,017 feet) tall, with radiating lava flows dating from the 1950s to the late 1980s. These active volcanoes constitute a hazard to the towns of Goma, Zaire and the nearby Rwandan refugee camps, located on the shore of Lake Kivu at the top left. This radar image highlights subtle differences in the vegetation of the region. The green patch to the center left of the image in the foothills of Karisimbi is a bamboo forest where the mountain gorillas live. The vegetation types in this area are an important factor in the habitat of mountain gorillas. Researchers at Rutgers University in New Jersey and the Dian Fossey Gorilla Fund in London will use this data to produce 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.

  20. Enhancing radar cross-section images of artificial targets using radar polarimetry

    NASA Astrophysics Data System (ADS)

    Dallmann, Thomas; Heberling, Dirk

    2015-05-01

    Nowadays polarimetric decompositions are common processing techniques for synthetic aperture radar images. However, some of the decomposition methods can also be applied to imagery obtained in radar cross-section measurement ranges. Since commonly artificial targets are measured in these ranges, coherent decompositions are of special interest for the analysis of these images. In this paper, a Kennaugh matrix decomposition is used to remove non-polarized clutter from fully polarized targets. Therefore two averaging techniques required for the decomposition will be compared. Also a variation of this decomposition which is related to a well-known image processing filter will be introduced. Finally it will be demonstrated that both methods can enhance the contrast of radar cross-section images.

  1. Space Radar Image of Taal Volcano, Philippines

    NASA Technical Reports Server (NTRS)

    1994-01-01

    This is an image of Taal volcano, near Manila on the island of Luzon in the Philippines. The black area in the center is Taal Lake, which nearly fills the 30-kilometer-diameter (18-mile) caldera. The caldera rim consists of deeply eroded hills and cliffs. The large island in Taal Lake, which itself contains a crater lake, is known as Volcano Island. The bright yellow patch on the southwest side of the island marks the site of an explosion crater that formed during a deadly eruption of Taal in 1965. 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 78th orbit on October 5, 1994. The image shows an area approximately 56 kilometers by 112 kilometers (34 miles by 68 miles) that is centered at 14.0 degrees north latitude and 121.0 degrees east longitude. North is toward the upper right 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 and vertically received); blue represents the C-band (horizontally transmitted and vertically received). Since 1572, Taal has erupted at least 34 times. Since early 1991, the volcano has been restless, with swarms of earthquakes, new steaming areas, ground fracturing, and increases in water temperature of the lake. Volcanologists and other local authorities are carefully monitoring Taal to understand if the current activity may foretell an eruption. Taal is one of 15 'Decade Volcanoes' that have been identified by the volcanology community as presenting large potential hazards to population centers. The bright area in the upper right of the image is the densely populated city of Manila, only 50 kilometers (30 miles) north of the central crater. Spaceborne Imaging Radar-C/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 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.

  2. 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.

  3. 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.

  4. 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. 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.

  5. Space Radar Image of Hong Kong, China

    NASA Technical Reports Server (NTRS)

    1994-01-01

    This is an X-SAR image spanning an area of approximately 20 kilometers by 40 kilometers (12 miles by 25 miles) of the island of Hong Kong, the Kowloon Peninsula and the new territories in southern China, taken by the imaging radar on board the space shuttle Endeavour on October 4, 1994. North is toward the top left corner of the image. The Kaitak Airport runway on Kowloon Peninsula (center right of image) was built on reclaimed land and extends almost 3 kilometers (nearly 2 miles) into Victoria Harbor. To the south of the harbor lies the island of Hong Kong. The bright areas around the harbor are the major residential and business districts. Housing more than six million residents, Hong Kong is the most densely populated area in the world. The large number of objects visible in the harbor and surrounding waters are a variety of sea-going vessels, anchored in one of the busiest seaports in the Far East. 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 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.

  6. Comparison of various enhanced radar imaging techniques

    NASA Astrophysics Data System (ADS)

    Gupta, Inder J.; Gandhe, Avinash

    1998-09-01

    Recently, many techniques have been proposed to enhance the quality of radar images obtained using SAR and/or ISAR. These techniques include spatially variant apodization (SVA), adaptive sidelobe reduction (ASR), the Capon method, amplitude and phase estimation of sinusoids (APES) and data extrapolation. SVA is a special case of ASR; whereas the APES algorithm is similar to the Capon method except that it provides a better amplitude estimate. In this paper, the ASR technique, the APES algorithm and data extrapolation are used to generate radar images of two experimental targets and an airborne target. It is shown that although for ideal situations (point targets) the APES algorithm provides the best radar images (reduced sidelobe level and sharp main lobe), its performance degrades quickly for real world targets. The ASR algorithm gives radar images with low sidelobes but at the cost of some loss of information about the target. Also, there is not much improvement in radar image resolution. Data extrapolation, on the other hand, improves image resolution. In this case one can reduce the sidelobes by using non-uniform weights. Any loss in the radar image resolution due to non-uniform weights can be compensated by further extrapolating the scattered field data.

  7. Space Radar Image of Colombian Volcano

    NASA Technical Reports Server (NTRS)

    1999-01-01

    This is a radar image of a little known volcano in northern Colombia. The image was acquired on orbit 80 of space shuttle Endeavour on April 14, 1994, by the Spaceborne Imaging Radar C/X-Band Synthetic Aperture Radar (SIR-C/X-SAR). The volcano near the center of the image is located at 5.6 degrees north latitude, 75.0 degrees west longitude, about 100 kilometers (65 miles) southeast of Medellin, Colombia. The conspicuous dark spot is a lake at the bottom of an approximately 3-kilometer-wide (1.9-mile) volcanic collapse depression or caldera. A cone-shaped peak on the bottom left (northeast rim) of the caldera appears to have been the source for a flow of material into the caldera. This is the northern-most known volcano in South America and because of its youthful appearance, should be considered dormant rather than extinct. The volcano's existence confirms a fracture zone proposed in 1985 as the northern boundary of volcanism in the Andes. The SIR-C/X-SAR image reveals another, older caldera further south in Colombia, along another proposed fracture zone. Although relatively conspicuous, these volcanoes have escaped widespread recognition because of frequent cloud cover that hinders remote sensing imaging in visible wavelengths. Four separate volcanoes in the Northern Andes nations ofColombia and Ecuador have been active during the last 10 years, killing more than 25,000 people, including scientists who were monitoring the volcanic activity. Detection and monitoring of volcanoes from space provides a safe way to investigate volcanism. The recognition of previously unknown volcanoes is important for hazard evaluations because a number of major eruptions this century have occurred at mountains that were not previously recognized as volcanoes. 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 companiesfor the German space agency, Deutsche Agentur fuer Raumfahrtange-legenheiten (DARA), and the Italian space agency,Agenzia SpazialeItaliana (ASI), with the Deutsche Forschungsanstalt fuer Luft undRaumfahrt e.v.(DLR), the major partner in science,operations, and data processing of X-SAR.

  8. Data volume reduction for imaging radar polarimetry

    NASA Technical Reports Server (NTRS)

    Zebker, Howard A. (Inventor); Held, Daniel N. (Inventor); van Zul, Jakob J. (Inventor); Dubois, Pascale C. (Inventor); Norikane, Lynne (Inventor)

    1989-01-01

    Two alternative methods are disclosed for digital reduction of synthetic aperture multipolarized radar data using scattering matrices, or using Stokes matrices, of four consecutive along-track pixels to produce averaged data for generating a synthetic polarization image.

  9. Data volume reduction for imaging radar polarimetry

    NASA Technical Reports Server (NTRS)

    Zebker, Howard A. (inventor); Held, Daniel N. (inventor); Vanzyl, Jakob J. (inventor); Dubois, Pascale C. (inventor); Norikane, Lynne (inventor)

    1988-01-01

    Two alternative methods are presented for digital reduction of synthetic aperture multipolarized radar data using scattering matrices, or using Stokes matrices, of four consecutive along-track pixels to produce averaged data for generating a synthetic polarization image.

  10. Delineation of fault zones using imaging radar

    NASA Technical Reports Server (NTRS)

    Toksoz, M. N.; Gulen, L.; Prange, M.; Matarese, J.; Pettengill, G. H.; Ford, P. G.

    1986-01-01

    The assessment of earthquake hazards and mineral and oil potential of a given region requires a detailed knowledge of geological structure, including the configuration of faults. Delineation of faults is traditionally based on three types of data: (1) seismicity data, which shows the location and magnitude of earthquake activity; (2) field mapping, which in remote areas is typically incomplete and of insufficient accuracy; and (3) remote sensing, including LANDSAT images and high altitude photography. Recently, high resolution radar images of tectonically active regions have been obtained by SEASAT and Shuttle Imaging Radar (SIR-A and SIR-B) systems. These radar images are sensitive to terrain slope variations and emphasize the topographic signatures of fault zones. Techniques were developed for using the radar data in conjunction with the traditional types of data to delineate major faults in well-known test sites, and to extend interpretation techniques to remote areas.

  11. Space Radar Image of Randonia Rain Cell

    NASA Technical Reports Server (NTRS)

    1994-01-01

    This multi-frequency space radar image of a tropical rainforest in western Brazil shows rapidly changing land use patterns and it also demonstrates the capability of the different radar frequencies to detect and penetrate heavy rainstorms. This color image was created by combining the three separate radar frequencies into a composite image. The three black and white images below represent the individual frequencies. The lower left image, X-band vertically transmitted and received, is blue in the color image; the lower center image, C-band horizontally transmitted and vertically received is green; and the lower right image, L-band horizontally transmitted and vertically received is red. A heavy downpour in the lower center of the image appears as a black 'cloud' in the X-band image, the same area is shows up faintly in the C-band image, and is invisible in the L-band image. When combined in the color image, the rain cell appears red and yellow. Although radar can usually 'see' through clouds, short radar wavelengths (high frequency), such as X and C-band, can be changed by unusually heavy rain cells. L-band, at a 24 cm (9 inches) wavelength, is unaffected by such rain cells. By analyzing the way the radar changes, scientist can estimate rainfall rates. The area shown is in the state of Rondonia, in western Brazil. The pink areas are pristine tropical rainforest, and the blue and green patches are areas where the forest has been cleared for agriculture. Cleared areas are typically able to support intense farming for a only few years, before soil erosion renders the fields unusable. Radar imaging can be used to monitor not only the rainforest destruction, but also the rates of recovery of abandoned fields. This image is 35.2 kilometers by 21.3 kilometers (21.8 miles by 13.2 miles) and is centered at 11.2 degrees south latitude, 61.7 degrees west longitude. North is toward the upper left. The image was acquired by the Spaceborne Imaging Radar-C/X-band Synthetic Aperture Radar (SIR-C/X-SAR) on April 10, 1994 onboard the space shuttle Endeavour. 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.

  12. Jamming cancellation algorithm for wideband imaging radar

    NASA Astrophysics Data System (ADS)

    Zheng, Yibin; Yu, Kai-Bor

    1998-10-01

    We describe a jamming cancellation algorithm for wide-band imaging radar. After reviewing high range resolution imaging principle, several key factors affecting jamming cancellation performances, such as the 'instantaneous narrow-band' assumption, bandwidth, de-chirped interference, are formulated and analyzed. Some numerical simulation results, using a hypothetical phased array radar and synthetic point targets, are presented. The results demonstrated the effectiveness of the proposed algorithm.

  13. Space Radar Image of Mt. Rainer, Washington

    NASA Technical Reports Server (NTRS)

    1994-01-01

    This is a radar image of Mount Rainier in Washington state. The volcano last erupted about 150 years ago and numerous large floods and debris flows have originated on its slopes during the last century. Today the volcano is heavily mantled with glaciers and snowfields. More than 100,000 people live on young volcanic mudflows less than 10,000 years old and, consequently, are within the range of future, devastating mudslides. 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 20th orbit on October 1, 1994. The area shown in the image is approximately 59 kilometers by 60 kilometers (36.5 miles by 37 miles). North is toward the top left of the image, which was composed by assigning red and green colors to the L-band, horizontally transmitted and vertically, and the L-band, horizontally transmitted and vertically received. Blue indicates the C-band, horizontally transmitted and vertically received. In addition to highlighting topographic slopes facing the space shuttle, SIR-C records rugged areas as brighter and smooth areas as darker. The scene was illuminated by the shuttle's radar from the northwest so that northwest-facing slopes are brighter and southeast-facing slopes are dark. Forested regions are pale green in color; clear cuts and bare ground are bluish or purple; ice is dark green and white. The round cone at the center of the image is the 14,435-foot (4,399-meter) active volcano, Mount Rainier. On the lower slopes is a zone of rock ridges and rubble (purple to reddish) above coniferous forests (in yellow/green). The western boundary of Mount Rainier National Park is seen as a transition from protected, old-growth forest to heavily logged private land, a mosaic of recent clear cuts (bright purple/blue) and partially regrown timber plantations (pale blue). The prominent river seen curving away from the mountain at the top of the image (to the northwest) is the White River, and the river leaving the mountain at the bottom right of the image (south) is the Nisqually River, which flows out of the Nisqually glacier on the mountain. The river leaving to the left of the mountain is the Carbon River, leading west and north toward heavily populated regions near Tacoma. The dark patch at the top right of the image is Bumping Lake. Other dark areas seen to the right of ridges throughout the image are radar shadow zones. Radar images can be used to study the volcanic structure and the surrounding regions with linear rock boundaries and faults. In addition, the recovery of forested lands from natural disasters and the success of reforestation programs can also be monitored. Ultimately this data may be used to study the advance and retreat of glaciers and other forces of global change. 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: the L-band (24 cm), the C-band (6 cm) and the 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.

  14. Feature utility in polarimetric radar image classification

    NASA Technical Reports Server (NTRS)

    Cumming, Ian G.; Van Zyl, Jakob J.

    1989-01-01

    The information content in polarimetric SAR images is examined, and the polarimetric image variables containing the information that is important to the classification of terrain features in the images are determined. It is concluded that accurate classification can be done when just over half of the image variables are retained. A reduction in image data dimensionality gives storage savings, and can lead to the improvement of classifier performance. In addition, it is shown that a simplified radar system with only phase-calibrated CO-POL or SINGLE TX channels can give classification performance which approaches that of a fully polarimetric radar.

  15. Space Radar Image of Bebedauro, Brazil, seasonal

    NASA Technical Reports Server (NTRS)

    1994-01-01

    This is an X-band image showing seasonal changes at the hydrological test site of Bebedouro in Brazil. The image is centered at 9 degrees south latitude and 40.2 degrees west longitude. 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 April 10, 1994, during the first flight of the radar system, and on October 1, 1994, during the second mission. The swath width is approximately 16.5 kilometers (10.5 miles) wide. The image channels have the following color assignments: red represents data acquired on April 10; green represents data acquired on October 1; blue corresponds to the ratio of the two data sets. Agriculture plays an important economic and social role in Brazil. One of the major problems related to Brazilian agriculture is estimating the size of planting areas and their productivity. Due to cloud cover and the rainy season, which occurs from November through April, optical and infrared Earth observations are seldom used to survey the region. An additional goal of monitoring this region is to watch the floodplains of rivers like Rio Sao Francisco in order to determine suitable locations for additional agricultural fields. This area belongs to the semi-arid northeastern region of Brazil, where estimates have suggested that about 10 times more land could be used for agriculture, including some locations which could be used for irrigation projects. Monitoring of soil moisture during the important summer crop season is of high priority for the future development and productivity of this region. In April the area was covered with vegetation because of the moisture of the soil and only small differences could be seen in X-band data. In October the run-off channels of this hilly region stand out quite clearly because the greenish areas indicated much less soil moisture and water content in plants. 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 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. Imaging coherent scatter radar, incoherent scatter radar, and optical observations of quasiperiodic structures associated with sporadic

    E-print Network

    Mendillo, Michael

    Imaging coherent scatter radar, incoherent scatter radar, and optical observations of quasiperiodic; published 20 June 2007. [1] During June and July 2002, a 30-MHz imaging coherent scatter radar was installed scatter radar. In six of those events, simultaneous measurements were made with the Arecibo 430-MHz

  17. Segmentation Of Multitemporal Side-Looking Airborne Radar (SLAR) Images

    NASA Astrophysics Data System (ADS)

    Gerbrands, Jan J.; Backer, Eric

    1983-10-01

    This paper describes a procedure developed for the automated segmentation of multiple side-looking airborne radar (SLAR) images, i.e. the detection of the boundaries of agricultural fields. The segmentation procedure is based on a split-and-merge algorithm which may process up to three input images simultaneously. The input images must be in registration. A registration method is proposed which uses coarse structural descriptions of the input images as represented by attributed quartic picture trees (QPT).

  18. Space Radar Image of Belgrade, Serbia

    NASA Technical Reports Server (NTRS)

    1994-01-01

    This spaceborne radar image of Belgrade, Serbia, illustrates the variety of land use patterns that can be observed with a multiple wavelength radar system. Belgrade, the capital of Serbia and former capital of Yugoslavia, is the bright area in the center of the image. The Danube River flows from the top to the bottom of the image, and the Sava River flows into the Danube from the left. Agricultural fields appear in shades of dark blue, purple and brown in outlying areas. Vegetated areas along the rivers appear in light blue-green, while dense forests in hillier areas in the lower left appear in a darker shade of green. The image was acquired by the Spaceborne Imaging Radar-C/X-Band Synthetic Aperture Radar (SIR-C/X-SAR) onboard the space shuttle Endeavour on October 2, 1994. The image is centered at 44.5 degrees north latitude and 20.5 degrees east longitude. North is toward the upper right. The image shows an area 36 kilometers by 32 kilometers 22 miles by 20 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; blue is C-band, horizontally transmitted, vertically 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 program.

  19. Compressed sensing technique for high-resolution radar imaging

    NASA Astrophysics Data System (ADS)

    Yoon, Yeo-Sun; Amin, Moeness G.

    2008-04-01

    Compressed sensing (CS) has recently attracted much interest because of its important offerings and versatility. High-resolution radar imaging applications such as through-the-wall radar (TWR) imaging or inverse synthetic aperture radar (ISAR) are two key application areas that can greatly benefit from CS. Both applications require probing targets using radar signals with large bandwidth for collecting, and then processing, a large number of data samples for achieving high resolution imaging. These applications are also characterized by sparse imaging where targets of interest are few and have larger cross-section than clutter objects. Reducing the number of samples without compromising the imaging quality reduces the acquisition time and saves signal bandwidth. This reduction is important when surveillance is performed within small time window and when targets are required to remain stationary without translation or rotation motions, to avoid blurring and smearing of images. In this paper, we discuss applicability of compressed sensing to indoor radar imaging, using synthesized TWR data.

  20. Doppler radar imaging of spherical planetary surfaces

    NASA Technical Reports Server (NTRS)

    Hudson, R. Scott; Ostro, Steven J.

    1990-01-01

    This paper describes a technique for using echo power-spectra for making radar images of spherical planetary targets. In developing the Doppler-radar imaging system, the target's reflectivity distribution is expanded in a truncated spherical harmonic series; the distribution of echo power in rotational phase and the Doppler frequency are obtained in form of a system of linear equations which express the echo spectra as functions of the series coefficients. To estimate the coefficients from an observed phase-Doppler distribution, the inversion is cast as a least-squares problem, and is solved using singular value decompositions, yielding a linear imaging system which can be fully characterized by its impulse response as a function of latitude. Simulations were designed and used to explore the capabilities of Doppler radar imaging, and the sensitivity of imaging to such factors as subradar altitude coverage and signal-to-noise ratio was investigated.

  1. Space Radar Image of Wenatchee, Washington

    NASA Technical Reports Server (NTRS)

    1994-01-01

    This spaceborne radar image shows a segment of the Columbia River as it passes through the area of Wenatchee, Washington, about 220 kilometers (136 miles) east of Seattle. The Wenatchee Mountains, part of the Cascade Range, are shown in green at the lower left of the image. The Cascades create a 'rain shadow' for the region, limiting rainfall east of the range to less than 26 centimeters (10 inches) per year. The radar's ability to see different types of vegetation is highlighted in the contrast between the pine forests, that appear in green and the dry valley plain that shows up as dark purple. The cities of Wenatchee and East Wenatchee are the grid-like areas straddling the Columbia River in the left center of the image. With a population of about 60,000, the region produces about half of Washington state's lucrative apple crop. Several orchard areas appear as green rectangular patches to the right of the river in the lower right center. Radar images such as these can be used to monitor land use patterns in areas such as Wenatchee, that have diverse and rapidly changing urban, agricultural and wild land pressures. This image was acquired by Spaceborne Imaging Radar-C/X-Band Synthetic Aperture Radar (SIR-C/X-SAR) onboard the space shuttle Endeavour on October 10, 1994. The image is 38 kilometers by 45 kilometers (24 miles by 30 miles) and is centered at 47.3 degrees North latitude, 120.1 degrees West longitude. North is toward the upper left. The colors are assigned to different radar frequencies and polarizations of the radar as follows: red is L-band, horizontally transmitted and received; green is L-band, horizontally transmitted, vertically received; and blue is C-band, horizontally transmitted, vertically 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.

  2. 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 development.

  3. Space Radar Image of Los Angeles, California

    NASA Technical Reports Server (NTRS)

    1994-01-01

    This radar image shows the massive urbanization of Los Angeles, California. The image extends from the Santa Monica Bay at the left to the San Gabriel Mountains at the right. Downtown Los Angeles is in the center of the image. The runways of the Los Angeles International Airport appear as black strips at the left center of the image. The waterways of Marina del Rey are seen just above the airport. The San Gabriel Mountains and the city of Pasadena are at the right center of the image. Black areas on the mountains on the right are fire scars from the 1993 Altadena fire. The Rose Bowl is shown as a small circle near the right center. The complex freeway system is visible as dark lines throughout the image. Some city areas, such as Santa Monica in the upper left, appear red due to the alignment of streets and buildings to the incoming radar beam. The image was acquired by the Spaceborne Imaging Radar-C/X-band Synthetic Aperture Radar (SIR-C/X-SAR) onboard the space shuttle Endeavour on October 3, 1994. 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. This image is centered at 34.04 degrees North latitude and 118.2 degrees West longitude with North pointing toward the upper right. The area shown measures 40 kilometers by 50 kilometers (25 miles by 31 miles).

  4. 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.

  5. Using doppler radar images to estimate aircraft navigational heading error

    DOEpatents

    Doerry, Armin W. (Albuquerque, NM); Jordan, Jay D. (Albuquerque, NM); Kim, Theodore J. (Albuquerque, NM)

    2012-07-03

    A yaw angle error of a motion measurement system carried on an aircraft for navigation is estimated from Doppler radar images captured using the aircraft. At least two radar pulses aimed at respectively different physical locations in a targeted area are transmitted from a radar antenna carried on the aircraft. At least two Doppler radar images that respectively correspond to the at least two transmitted radar pulses are produced. These images are used to produce an estimate of the yaw angle error.

  6. Compact Ku-Band T/R Module for High-Resolution Radar Imaging of Cold Land Processes

    NASA Technical Reports Server (NTRS)

    Andricos, Constantine; Yueh, Simon H.; Krimskiy, Vladimir A.; Rahmat-Samii, Yahya

    2010-01-01

    Global measurement of terrestrial snow cover is critical to two of the NASA Earth Science focus areas: (1) climate variability and change and (2) water and energy cycle. For radar backscatter measurements, Ku-band frequencies, scattered mainly within the volume of the snowpack, are most suitable for the SWE (snow-water equivalent) measurements. To isolate the complex effects of different snowpack (density and snowgrain size), and underlying soil properties and to distinctly determine SWE, the space-based synthetic aperture radar (SAR) system will require a dual-frequency (13.4 and 17.2 GHz) and dual polarization approach. A transmit/receive (T/R) module was developed operating at Ku-band frequencies to enable the use of active electronic scanning phased-array antenna for wide-swath, high-resolution SAR imaging of terrestrial snow cover. The T/R module has an integrated calibrator, which compensates for all environmental- and time-related changes, and results in very stable power and amplitude characteristics. The module was designed to operate over the full frequency range of 13 to 18 GHz, although only the two frequencies, 13.4 GHz and 17.2 GHz, will be used in this SAR radar application. Each channel of the transmit module produces > 4 W (35 dbm) over the operating bandwidth of 20 MHz. The stability requirements of <0.1 dB receive gain accuracy and <0.1 dB transmit power accuracy over a wide temperature range are achieved using a self-correction scheme, which does real-time amplitude calibration so that the module characteristics are continually corrected. All the calibration circuits are within the T/R module. The timing and calibration sequence is stored in a control FPGA (field-programmable gate array) while an internal 128K 8bit high-speed RAM (random access memory) stores all the calibration values. The module was designed using advanced components and packaging techniques to achieve integration of the electronics in a 2 x6.5x1-in. (5x17x2.5-cm) package. The module size allows 4 T/R modules to feed the 16 16-element subarray on an antenna panel. The T/R module contains four transmit channels and eight receive channels (horizontal and vertical polarizations).

  7. Space Radar Image of Safsaf Oasis, Egypt

    NASA Technical Reports Server (NTRS)

    1994-01-01

    This three-frequency space radar image of south-central Egypt demonstrates the unique capability of imaging radar to penetrate thin sand cover in arid regions to reveal hidden details below the surface. Nearly all of the structures seen in this image are invisible to the naked eye and to conventional optical satellite sensors. Features appear in various colors because the three separate radar wavelengths are able to penetrate the sand to different depths. Areas that appear red or orange are places that can be seen only by the longest wavelength, L-band, and they are the deepest of the buried structures. Field studies in this area indicate L-band can penetrate as much as 2 meters (6.5 feet) of very dry sand to image buried rock structures. Ancient drainage channels at the bottom of the image are filled with sand more than 2 meters (6.5 feet) thick and therefore appear dark because the radar waves cannot penetrate them. The fractured orange areas at the top of the image and the blue circular structures in the center of the image are granitic areas that may contain mineral ore deposits. Scientists are using the penetrating capabilities of radar imaging in desert areas in studies of structural geology, mineral exploration, ancient climates, water resources and archaeology. This image is 51.9 kilometers by 30.2 kilometers (32.2 miles by 18.7 miles) and is centered at 22.7 degrees north latitude, 29.3degrees east longitude. North is toward the upper right. The colors are assigned to different radar frequencies and polarizations as follows: red is L-band, horizontally transmitted and received; green is C-band, horizontally transmitted and received; and blue is X-band, vertically transmitted and received. The image was acquired by the Spaceborne Imaging Radar-C/X-band Synthetic Aperture Radar (SIR-C/X-SAR) on April 16, 1994, on board the space shuttle Endeavour. 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 program.

  8. Space Radar Image of Weddell Sea, Antarctica

    NASA Technical Reports Server (NTRS)

    1994-01-01

    This Spaceborne Imaging Radar-C/X-band Synthetic Aperture Radar color composite shows a portion of the Weddell Sea, which is adjacent to the continent of Antarctica. The image shows extensive coverage of first-year sea ice mixtures and patches of open water inside the ice margin. The image covers a 100 kilometer by 30 kilometer (62 mile by 18.5 mile) region of the southern ocean, centered at approximately 57 degrees south latitude and 3 degrees east longitude, which was acquired on October 3, 1994. Data used to create this image were obtained using the L-band (horizontally transmitted and vertically received) in red; the L-band (horizontally transmitted and received) in green; and the C-band (horizontally transmitted and received) in blue. The sea ice, which appears rust-brown in the image, is composed of loosely packed floes from approximately 1 meter to 2 meters (3 feet to 6.5 feet) thick and ranging from 1 meter to 20 meters (3 feet to 65.5 feet) in diameter. Large patches of open water, shown as turquoise blue, are scattered throughout the area, which is typical for ice margins experiencing off-ice winds. The thin, well-organized lines clearly visible in the ice pack are caused by radar energy reflected by floes riding the crest of ocean swells. The wispy, black features seen throughout the image represent areas where new ice is forming. Sea ice, because it acts as an insulator, reduces the loss of heat between the relatively warm ocean and cold atmosphere. This interaction is an important component of the global climate system. Because of the unique combination of winds, currents and temperatures found in this region, ice can extend many hundreds of kilometers north of Antarctica each winter, which classifies the Weddell Sea as one of nature's greatest ice-making engines. During the formation of sea ice, great quantities of salt are expelled from the frozen water. The salt increases the density of the upper layer of sea water, which then sinks to great depths. Oceanographers believe this process forms most of the oceans' deep water. Sea ice covering all of the southern oceans, including the Weddell Sea, typically reaches its most northerly extent in about September. As periods of daylight become gradually longer in the Southern Hemisphere, ice formation stops and the ice edge retreats southward. By February, most of the sea ice surrounding Antarctica disappears. Imaging radar is extremely useful for studying the polar regions because of the long periods of darkness and extensive cloud cover. The multiple frequencies of the SIR-C/X-SAR instruments allow further study into ways of improving the separation of the various thickness ranges of sea ice, which are vital to understanding the heat balance in the ice, ocean and atmospheric system. 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 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.

  9. 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.

  10. Space Radar Image of Star City, Russia

    NASA Technical Reports Server (NTRS)

    1994-01-01

    This radar image shows the Star City cosmonaut training center, east of Moscow, Russia. Four American astronauts are training here for future long-duration flights aboard the Russian Mir space station. These joint flights are giving NASA and the Russian Space Agency experience necessary for the construction of the international Alpha space station, beginning in late 1997. This image was acquired by the Spaceborne Imaging Radar-C/X-band Synthetic Aperture Radar (SIR-C/X-SAR), on its 62nd orbit on October 3, 1994. This Star City image is centered at 55.55 degrees north latitude and 38.0 degrees east longitude. The area shown is approximately 32 kilometers by 49 kilometers (20 miles by 30 miles). North is to the top in this image. The radar illumination is from the top of the image. The image was produced using three channels of SIR-C radar data: red indicates L-band (23 cm wavelength, horizontally transmitted and received); green indicates L-band (horizontally transmitted and vertically received); blue indicates C-band (6 cm wavelength, horizontally transmitted and vertically received). In general, dark pink areas are agricultural; pink and light blue areas are urban communities; black areas represent lakes and rivers; dark blue areas are cleared forest; and light green areas are forested. The prominent black runways just right of center are Shchelkovo Airfield, about 4 km long. The textured pale blue-green area east and southeast of Shchelkovo Airfield is forest. Just east of the runways is a thin railroad line running southeast; the Star City compound lies just east of the small bend in the rail line. Star City contains the living quarters and training facilities for Russian cosmonauts and their families. Moscow's inner loop road is visible at the lower left edge of the image. The Kremlin is just off the left edge, on the banks of the meandering Moskva River. The Klyazma River snakes to the southeast from the reservoir in the upper left (shown in bright red), passing just east of Star City and flowing off the lower right edge of the image. The dark blue band of the Vorya River runs north-south in the upper right quadrant, east of Star City. SIR-C/X-SAR radar images are being compared with data from the Russian radar satellite Almaz to evaluate the usefulness of a permanent orbital radar platform in monitoring Earth s environment and ecology.

  11. Radar transponder apparatus and signal processing technique

    DOEpatents

    Axline, R.M. Jr.; Sloan, G.R.; Spalding, R.E.

    1996-01-23

    An active, phase-coded, time-grating transponder and a synthetic-aperture radar (SAR) and signal processor means, in combination, allow the recognition and location of the transponder (tag) in the SAR image and allow communication of information messages from the transponder to the SAR. The SAR is an illuminating radar having special processing modifications in an image-formation processor to receive an echo from a remote transponder, after the transponder receives and retransmits the SAR illuminations, and to enhance the transponder`s echo relative to surrounding ground clutter by recognizing special transponder modulations from phase-shifted from the transponder retransmissions. The remote radio-frequency tag also transmits information to the SAR through a single antenna that also serves to receive the SAR illuminations. Unique tag-modulation and SAR signal processing techniques, in combination, allow the detection and precise geographical location of the tag through the reduction of interfering signals from ground clutter, and allow communication of environmental and status information from said tag to be communicated to said SAR. 4 figs.

  12. Radar transponder apparatus and signal processing technique

    DOEpatents

    Axline, Jr., Robert M. (Albuquerque, NM); Sloan, George R. (Albuquerque, NM); Spalding, Richard E. (Albuquerque, NM)

    1996-01-01

    An active, phase-coded, time-grating transponder and a synthetic-aperture radar (SAR) and signal processor means, in combination, allow the recognition and location of the transponder (tag) in the SAR image and allow communication of information messages from the transponder to the SAR. The SAR is an illuminating radar having special processing modifications in an image-formation processor to receive an echo from a remote transponder, after the transponder receives and retransmits the SAR illuminations, and to enhance the transponder's echo relative to surrounding ground clutter by recognizing special transponder modulations from phase-shifted from the transponder retransmissions. The remote radio-frequency tag also transmits information to the SAR through a single antenna that also serves to receive the SAR illuminations. Unique tag-modulation and SAR signal processing techniques, in combination, allow the detection and precise geographical location of the tag through the reduction of interfering signals from ground clutter, and allow communication of environmental and status information from said tag to be communicated to said SAR.

  13. Space Radar Image of Ventura County, California

    NASA Technical Reports Server (NTRS)

    1994-01-01

    This radar image of Ventura County, California, shows the Santa Clara River valley and the surrounding mountains. The river valley is the linear feature that extends from the lower right to the upper left (east to west), where it empties into the Pacific Ocean (dark patches in upper and lower left). The cities of Ventura and Oxnard are seen along the left side of the image. Simi Valley is located in the lower center of the image, between the Santa Monica Mountains (purple area in lower left) and the Santa Susanna Mountains to the north. This area of California is known for its fruit; strawberry fields are shown in red and purple rectangular areas on the coastal plain, and citrus groves are the yellow green areas adjacent to the river. This image is centered at 34.33 degrees north latitude, 119 degrees west longitude. The area shown is approximately 53 kilometers by 35 kilometers (33 miles by 22 miles). Colors are assigned to different radar frequencies and polarizations as follows: red is L-band, horizontally transmitted, horizontally received; green is L-band, horizontally transmitted, vertically received; blue is C-band, horizontally transmitted, vertically received. The image was acquired by the Spaceborne Imaging Radar-C/X-band Synthetic Aperture (SIR-C/X-SAR) imaging radar when it flew aboard the space shuttle Endeavour on October 6, 1994.

  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 forthcoming Canadian RADARSAT satellite. 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 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.

  15. Space Radar Image of Athens, Greece

    NASA Technical Reports Server (NTRS)

    1994-01-01

    This space radar image of Athens, Greece, shows the sprawling, modern development of this ancient capital city. Densely populated urban areas appear in shades of pink and light green. The Acropolis the dark green triangular patch in the center of the image. Archaeological discoveries indicate Athens has been continuously occupied for at least the last 5,000 years. Numerous ships, shown as bright dots, are seen in the harbor areas in the upper left part of the image. The port city of Piraeus is at the left center. This image is 45 kilometers by 45 kilometers (28 miles by 28 miles) and is centered at 37.9 degrees north latitude, 23.7 degrees east longitude. North is toward the upper right. The colors are assigned to different radar frequencies and polarizations are as follows: red is L-band, horizontally transmitted and received; green is L-band, horizontally transmitted and vertically received; and blue is C-band, horizontally transmitted and received. The image was acquired by the Spaceborne Imaging Radar-C/X-band Synthetic Aperture Radar (SIR-C/X-SAR) on October 2, 1994 onboard the space shuttle Endeavour. 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 program.

  16. Space Radar Image of Teide Volcano

    NASA Technical Reports Server (NTRS)

    1994-01-01

    This radar image shows the Teide volcano on the island of Tenerife in the Canary Islands. The Canary Islands, part of Spain, are located in the eastern Atlantic Ocean off the coast of Morocco. Teide has erupted only once in the 20th Century, in 1909, but is considered a potentially threatening volcano due to its proximity to the city of Santa Cruz de Tenerife, shown in this image as the purple and white area on the lower right edge of the island. The summit crater of Teide, clearly visible in the left center of the image, contains lava flows of various ages and roughnesses that appear in shades of green and brown. Different vegetation zones, both natural and agricultural, are detected by the radar as areas of purple, green and yellow on the volcano's flanks. Scientists are using images such as this to understand the evolution of the structure of Teide, especially the formation of the summit caldera and the potential for collapse of the flanks. The volcano is one of 15 identified by scientists as potentially hazardous to local populations, as part of the international The image was acquired by the Spaceborne Imaging Radar-C/X-Band Synthetic Aperture Radar (SIR-C/X-SAR) onboard the space shuttle Endeavour on October 11, 1994. 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. The image is centered at 28.3 degrees North latitude and 16.6 degrees West longitude. North is toward the upper right. The area shown measures 90 kilometers by 54.5 kilometers (55.8 miles by 33.8 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; green is L-band horizontally transmitted, vertically received; blue is C-band horizontally transmitted, vertically received.

  17. Space Radar Image of Honolulu, Oahu, Hawaii

    NASA Technical Reports Server (NTRS)

    1994-01-01

    This spaceborne 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, along the bottom of this image. Diamond Head, an extinct volcanic crater, is seen in the lower right. The bright white strip left of Diamond Head is the Waikiki Beach area. Further west are the downtown area and harbor. Runways of the airport can be seen in the lower left. 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. Densely vegetated areas appear green in this radar image, while urban areas generally appear orange, red or white. Images such as this can be used by land use planners to monitor urban development and its effect on the tropical environment. The image was acquired by the Spaceborne Imaging Radar-C/X-Band Synthetic Aperture Radar (SIR-C/X-SAR) onboard the space shuttleEndeavour on October 6, 1994.The image is 20.6 kilometers by 31.0kilometers (12.8 miles by 19.2 miles) and is centered at 21.4degrees North latitude, 157.8 degrees West longitude. North is toward the upper left. The colors are assigned to different radarfrequencies and polarizations of the radar as follows: red is L-band, horizontally transmitted and received; green is L-band, horizontally transmitted, vertically received; and blue is C-band, horizontally transmitted, vertically 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.

  18. Space Radar Image of Death Valley, California

    NASA Technical Reports Server (NTRS)

    1999-01-01

    This image shows Death Valley, California, centered at 36.629 degrees north latitude, 117.069 degrees west longitude. The image shows Furnace Creek alluvial fan and Furnace Creek Ranch at the far right, and the sand dunes near Stove Pipe Wells at the center. The dark fork-shaped feature between Furnace Creek fan and the dunes is a smooth flood-plain which encloses Cottonball Basin. This SIR-C/X-SAR supersite is an area of extensive field investigations and has been visited by both Space Radar Lab astronaut crews. Elevations in the valley range from 70 meters (230 feet) below sea level, the lowest in the United States, to more than 3,300 meters (10,800 feet) above sea level. Scientists are using SIR-C/X-SAR data from Death Valley to help answer a number of different questions about Earth's geology. One question concerns how alluvial fans are formed and change through time under the influence of climatic changes and earthquakes. Alluvial fans are gravel deposits that wash down from the mountains over time. They are visible in the image as circular, fan-shaped bright areas extending into the darker valley floor from the mountains. Information about the alluvial fans helps scientists study Earth's ancient climate. Scientists know the fans are built up through climatic and tectonic processes and they will use the SIR-C/X-SAR data to understand the nature and rates of weathering processes on the fans, soil formation and the transport of sand and dust by the wind. SIR-C/X-SAR's sensitivity to centimeter-scale (inch-scale) roughness provides detailed maps of surface texture. Such information can be used to study the occurrence and movement of dust storms and sand dunes. The goal of these studies is to gain a better understanding of the record of past climatic changes and the effects of those changes on a sensitive environment. This may lead to a better ability to predict future response of the land to different potential global climate-change scenarios. Death Valley is also one of the primary calibration sites for SIR-C/X-SAR. The bright dots near the center of the image are corner reflectors that have been set-up to calibrate the radar as the shuttle passes overhead. Thirty triangular-shaped reflectors (they look like aluminum pyramids) have been deployed by the calibration team from JPL over a 40- by 40-kilometer (25- by 25-mile) area in and around Death Valley. The calibration team will also deploy transponders (electronic reflectors) and receivers to measure the radar signals from SIR-C/X-SAR on the ground. 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).

  19. High-Altitude Cassini Radar Imaging of Titan

    NASA Astrophysics Data System (ADS)

    West, R. D.; Stiles, B.; Anderson, Y.; Boehmer, R.; Callahan, P.; Gim, Y.; Hamilton, G.; Hensley, S.; Janssen, M.; Johnson, W. T.; Kelleher, K.; Lorenz, R.; Ostro, S.; Paganelli, F.; Shaffer, S.; Wye, L.; Zebker, H.

    2006-12-01

    The Cassini spacecraft is now about halfway through its primary Tour of the Saturn system. By the time of this meeting, the radar instrument will have collected seven synthetic aperture strips during close flyby's, with 13 more to come. These images have resolutions as fine as 300 m. We present here data acquired using another imaging mode, very high altitude synthetic aperture radar (SAR) imaging, which extends imaging radar coverage and increases coincidental coverage with other Cassini imaging instruments such as VIMS and ISS. We also discuss calibration of SAR images and other radar data from additional engineering observations. Here we examine the performance trade-offs, special processing issues, and science potential of the high- altitude image observations, and the latest results from the calibration data. The high-altitude data collections are distinct from the normal Titan radar images because the range is much larger (around 20,000 km vs 950 km to 5000 km for normal SAR passes). To increase the signal to noise ratio in these circumstances, the radar operates in the lowest bandwidth scatterometer mode while spacecraft pointing control is used to slowly pan the central beam across a small swath. These high altitude images incorporate 150-200 independent looks in order to let us discriminate features that may lie below the noise floor. So far, three high-altitude images have been acquired, during Titan flyby's T12, T13, and T15. In T12 imaging was attempted from 37000 km with an effective resolution around 5 km. In T13 the Huygens Probe landing site was imaged from 11000 km with effective resolution of 1 2 km. In T15 the Tsegehi area was imaged from 20000 km with effective resolution of 2 -3 km. Additional high altitude image segments are also planned during the T19 and T20 Titan flyby's. The calibration observations are conducted independently or coupled with a distant icy satellite observation. They consist of receive-only data in all four bandwidths provided by the radar (117, 468, 937, and 4675 kHz) and use many different back-end attenuation settings while observing cold space and a known reference such as Saturn. These data are used to characterize the system's performance.

  20. 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.

  1. 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.

  2. 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-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 (DLR) and Italian (ASI) space agencies. It is managed by NASA's Jet Propulsion Laboratory, Pasadena, CA, for NASA's Earth Science Enterprise,Washington, DC.

    Size: 56 by 50 kilometers (35 by 32 miles) Location: 17 deg. North lat., 54 deg. East lon. Orientation: North at top Date Acquired: February 15, 2000

  3. Doppler Synthetic Aperture Radar Imaging Ling Wanga and Birsen Yazicib

    E-print Network

    Yazici, Birsen

    Doppler Synthetic Aperture Radar Imaging Ling Wanga and Birsen Yazicib aDepartment of Information, which we refer to as Doppler Synthetic Aperture Radar (DSAR). We present a novel image formation method, Continuous Wave (CW), Doppler, Backprojection 1. INTRODUCTION We consider a synthetic aperture radar imaging

  4. Mississippi Delta, Radar Image with Colored Height

    NASA Technical Reports Server (NTRS)

    2005-01-01

    [figure removed for brevity, see original site] Click on the image for the animation

    About the animation: This simulated view of the potential effects of storm surge flooding on Lake Pontchartrain and the New Orleans area was generated with data from the Shuttle Radar Topography Mission. Although it is protected by levees and sea walls against storm surges of 18 to 20 feet, much of the city is below sea level, and flooding due to storm surges caused by major hurricanes is a concern. The animation shows regions that, if unprotected, would be inundated with water. The animation depicts flooding in one-meter increments.

    About the image: The geography of the New Orleans and Mississippi delta region is well shown in this radar image from the Shuttle Radar Topography Mission. In this image, bright areas show regions of high radar reflectivity, such as from urban areas, and elevations have been coded in color using height data also from the mission. Dark green colors indicate low elevations, rising through yellow and tan, to white at the highest elevations.

    New Orleans is situated along the southern shore of Lake Pontchartrain, the large, roughly circular lake near the center of the image. The line spanning the lake is the Lake Pontchartrain Causeway, the world's longest over water highway bridge. Major portions of the city of New Orleans are below sea level, and although it is protected by levees and sea walls, flooding during storm surges associated with major hurricanes is a significant concern.

    Data used in this image were acquired by the Shuttle Radar Topography Mission aboard the Space Shuttle Endeavour, launched on Feb. 11, 2000. The mission used the same radar instrument that comprised the Spaceborne Imaging Radar-C/X-Band Synthetic Aperture Radar that flew twice on the Space Shuttle Endeavour in 1994. The Shuttle Radar Topography Mission was designed to collect 3-D measurements of the Earth's surface. To collect the 3-D data, engineers added a 60-meter (approximately 200-foot) mast, installed additional C-band and X-band antennas, and improved tracking and navigation devices. The mission is a cooperative project between NASA, the National Geospatial-Intelligence Agency of the U.S. Department of Defense and the German and Italian space agencies. It is managed by NASA's Jet Propulsion Laboratory, Pasadena, Calif., for NASA's Science Mission Directorate, Washington, D.C.

    Location: 30 degrees North latitude, 90 degrees East longitude Orientation: North toward the top, Mercator projection Size: 222.6 by 192.8 kilometers (138.3 by 119.8 miles) Image Data: Radar image and colored Shuttle Radar Topography Mission elevation model Date Acquired: February 2000

  5. Space Radar Image of Hong Kong

    NASA Technical Reports Server (NTRS)

    1994-01-01

    This spaceborne radar image shows part of the British territory of Hong Kong, adjacent to mainland China. The South China Sea is shown in dark blue and red on the image. Land surfaces are seen in shades of lighter blue and gold, including Hong Kong Island in the lower center, the Kowloon Peninsula in the upper right and many other small islands. The brightest yellow areas are the densely developed areas of Hong Kong's business and residential districts. The small yellow dots in the water are the many ships that make Hong Kong one of the busiest seaports in the Far East. Images such as this can be used by land-use planners to monitor urban development and its effect on the tropical environment. The image was acquired by the Spaceborne Imaging Radar-C/X-band Synthetic Aperture Radar (SIR-C/X-SAR) onboard the space shuttle Endeavour on October 10, 1994. The image is 23 kilometers by 31 kilometers (14 miles by 19 miles) and is centered at 22.3 degreesnorth latitude, 114.1 degrees east longitude. North is toward theupper right. The colors are assigned to different radar frequenciesand polarizations of the radar as follows: red is L-band, verticallytransmitted and received; green is C-band, vertically transmitted and received; and blue is C-band minus L-band, both vertically transmitted and received. SIR-C/X-SAR, a joint mission of theGerman, Italian and United States space agencies, is part of NASA's Mission to Planet Earth.

  6. Bibliography of geologic studies using imaging radar

    NASA Technical Reports Server (NTRS)

    Bryan, M. L.

    1979-01-01

    Articles concerning imaging studies on the geomorphology, mineralogy, and topology of various landforms are reported. One hundred and ninety citations are listed and an index by National Technical Information service citation number is included. Several illustrations of L-band radar imagery are presented.

  7. 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, called pahoehoe flows, are depicted in red, and rougher flows, called a'a flows in volcanology terminology that originated in the Hawaiian language, are shown in yellow and white. Mauna Loa 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 towns of Hilo and Kona. The Kilauea volcano is located off to the right of Mauna Loa and is not visible in this image.

  8. 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.

  9. Space Radar Image of Harvard Forest

    NASA Technical Reports Server (NTRS)

    1999-01-01

    This is a radar image of the area surrounding the Harvard Forest in north-central Massachusetts that has been operated as a ecological research facility by Harvard University since 1907. At the center of the image is the Quabbin Reservoir, and the Connecticut River is at the lower left of the image. The Harvard Forest itself is just above the reservoir. Researchers are comparing the naturally occurring physical disturbances in the forest and the recent and projected chemical disturbances and their effects on the forest ecosystem. Agricultural land appears dark blue/purple, along with low shrub vegetation and some wetlands. Urban development is bright pink; the yellow to green tints are conifer-dominated vegetation with the pitch pine sand plain at the middle left edge of the image appearing very distinctive. The green tint may indicate pure pine plantation stands, and deciduous broadleaf trees appear gray/pink with perhaps wetter sites being pinker. This image was acquired by the Spaceborne Imaging Radar-C/X-Band Synthetic Aperture Radar (SIR-C/X-SAR) aboard the space shuttle Endeavour. 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. The image is centered at 42.50 degrees North latitude and 72.33 degrees West longitude and covers an area of 53 kilometers 63 by kilometers (33 miles by 39 miles). The colors in the image are assigned to different frequencies and polarizations of the radar as follows: red is L-band horizontally transmitted and horizontally received; green is L-band horizontally transmitted and vertically received; and blue is C-band horizontally transmitted and horizontally received.

  10. Biometric Identification Using Holographic Radar Imaging Techniques

    SciTech Connect

    McMakin, Douglas L.; Sheen, David M.; Hall, Thomas E.; Kennedy, Mike O.; Foote, Harlan P.

    2007-04-01

    Pacific Northwest National Laboratory researchers have been at the forefront of developing innovative screening systems to enhance security and a novel imaging system to provide custom-fit clothing using holographic radar imaging techniques. First-of-a-kind cylindrical holographic imaging systems have been developed to screen people at security checkpoints for the detection of concealed, body worn, non-metallic threats such as plastic and liquid explosives, knifes and contraband. Another embodiment of this technology is capable of obtaining full sized body measurements in near real time without the person under surveillance removing their outer garments. Radar signals readily penetrate clothing and reflect off the water in skin. This full body measurement system is commercially available for best fitting ready to wear clothing, which was the first “biometric” application for this technology. One compelling feature of this technology for security biometric applications is that it can see effectively through disguises, appliances and body hair.

  11. Imaging radar polarimetry from wave synthesis

    NASA Technical Reports Server (NTRS)

    Zebker, Howard A.; Vanzyl, Jacob J.; Held, Daniel N.

    1986-01-01

    It was shown that it is possible to measure the complete scattering matrix of an object using data acquired on a single aircraft pass, and can combine the signals later in the data processor to generate radar images corresponding to any desired combination of transmit and receive polarization. Various scattering models predict different dependence on polarization state of received power from an object. The imaging polarimeter permits determination of this dependence, which is called the polarization signature, of each point in a radar image. Comparison of the theoretical predictions and observational data yield identification of possible scattering mechanisms for each area of interest. It was found that backscatter from the ocean is highly polarized and well-modeled by Bragg scattering, while scattering from trees in a city park possesses a considerable unpolarized component. Urban regions exhibit the characteristics expected from dihedral corner reflectors and their polarization signatures are quite different from the one-bounce Bragg model.

  12. Improving Ground Penetrating Radar Imaging in High Loss Environments by Coordinated System Development, Data Processing, Numerical Modeling, and Visualization Methods with Applications to Site Characterization

    SciTech Connect

    Wright, David L.

    2003-06-01

    The Department of Energy has identified the location and characterization of subsurface contaminants and the characterization of the subsurface as a priority need. Many DOE facilities are in need of subsurface imaging in the vadose and saturated zones. This includes (1) the detection and characterization of metal and concrete structures, (2) the characterization of waste pits (for both contents and integrity) and (3) mapping the complex geological/hydrological framework of the vadose and saturated zones. The DOE has identified ground penetrating radar (GPR) as a method that can non-invasively map transportation pathways and vadose zone heterogeneity. An advanced GPR system and advanced subsurface modeling, processing, imaging, and inversion techniques can be directly applied to several DOE science needs in more than one focus area and at many sites. Needs for enhanced subsurface imaging have been identified at Hanford, INEEL, SRS, ORNL, LLNL, SNL, LANL, and many other sites. In fact, needs for better subsurface imaging probably exist at all DOE sites. However, GPR performance is often inadequate due to increased attenuation and dispersion when soil conductivities are high.

  13. Space Radar Image of Sydney, Australia

    NASA Technical Reports Server (NTRS)

    1994-01-01

    This spaceborne radar image is dominated by the metropolitan area of Australia's largest city, Sydney. Sydney Harbour, with numerous coves and inlets, is seen in the upper center of the image, and the roughly circular Botany Bay is shown in the lower right. The downtown business district of Sydney appears as a bright white area just above the center of the image. The Sydney Harbour Bridge is a white line adjacent to the downtown district. The well-known Sydney Opera House is the small, white dot to the right of the bridge. Urban areas appear yellow, blue and brown. The purple areas are undeveloped areas and park lands. Manly, the famous surfing beach, is shown in yellow at the top center of the image. Runways from the Sydney Airport are the dark features that extend into Botany Bay in the lower right. Botany Bay is the site where Captain James Cook first landed his ship, Endeavour, in 1770. The image was acquired by the Spaceborne Imaging Radar-C/X-band Synthetic Aperture Radar (SIR-C/X-SAR) on April 20, 1994, onboard the space shuttle Endeavour. The area shown is 33 kilometers by 38kilometers (20 miles by 23 miles) and is centered at 33.9 degrees south latitude, 151.2 degrees east longitude. North is toward the upper left. The colors are assigned to different radar frequenciesand polarizations as follows: red is L-band, vertically transmittedand horizontally received; green is C-band, vertically transmitted and horizontally received; and blue is C-band, vertically transmittedand received. SIR-C/X-SAR, a joint mission of the German, Italianand United States space agencies, is part of NASA's Mission to Planet Earth. #####

  14. Radar signal pre-processing to suppress surface bounce and multipath

    DOEpatents

    Paglieroni, David W; Mast, Jeffrey E; Beer, N. Reginald

    2013-12-31

    A method and system for detecting the presence of subsurface objects within a medium is provided. In some embodiments, the imaging and detection system operates in a multistatic mode to collect radar return signals generated by an array of transceiver antenna pairs that is positioned across the surface and that travels down the surface. The imaging and detection system pre-processes that return signal to suppress certain undesirable effects. The imaging and detection system then generates synthetic aperture radar images from real aperture radar images generated from the pre-processed return signal. The imaging and detection system then post-processes the synthetic aperture radar images to improve detection of subsurface objects. The imaging and detection system identifies peaks in the energy levels of the post-processed image frame, which indicates the presence of a subsurface object.

  15. Space Radar Image Isla Isabela in 3-D

    NASA Technical Reports Server (NTRS)

    1999-01-01

    This is a three-dimensional view of Isabela, one of the Galapagos Islands located off the western coast of Ecuador, South America. This view was constructed by overlaying a Spaceborne Imaging Radar-C/X-band Synthetic Aperture Radar (SIR-C/X-SAR) image on a digital elevation map produced by TOPSAR, a prototype airborne interferometric radar which produces simultaneous image and elevation data. The vertical scale in this image is exaggerated by a factor of 1.87. The SIR-C/X-SAR image was taken on the 40th orbit of space shuttle Endeavour. The image is centered at about 0.5 degree south latitude and 91 degrees west longitude and covers an area of 75 by 60 kilometers (47 by 37 miles). The radar incidence angle at the center of the image is about 20 degrees. The western Galapagos Islands, which lie about 1,200 kilometers (750 miles)west of Ecuador in the eastern Pacific, have six active volcanoes similar to the volcanoes found in Hawaii and reflect the volcanic processes that occur where the ocean floor is created. Since the time of Charles Darwin's visit to the area in 1835, there have been more than 60 recorded eruptions on these volcanoes. This SIR-C/X-SAR image of Alcedo and Sierra Negra volcanoes shows the rougher lava flows as bright features, while ash deposits and smooth pahoehoe lava flows appear dark. Vertical exaggeration of relief is a common tool scientists use to detect relationships between structure (for example, faults, and fractures) and topography. 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).

  16. Radar image and data fusion for natural hazards characterisation

    USGS Publications Warehouse

    Lu, Zhong; Dzurisin, Daniel; Jung, Hyung-Sup; Zhang, Jixian; Zhang, Yonghong

    2010-01-01

    Fusion of synthetic aperture radar (SAR) images through interferometric, polarimetric and tomographic processing provides an all - weather imaging capability to characterise and monitor various natural hazards. This article outlines interferometric synthetic aperture radar (InSAR) processing and products and their utility for natural hazards characterisation, provides an overview of the techniques and applications related to fusion of SAR/InSAR images with optical and other images and highlights the emerging SAR fusion technologies. In addition to providing precise land - surface digital elevation maps, SAR - derived imaging products can map millimetre - scale elevation changes driven by volcanic, seismic and hydrogeologic processes, by landslides and wildfires and other natural hazards. With products derived from the fusion of SAR and other images, scientists can monitor the progress of flooding, estimate water storage changes in wetlands for improved hydrological modelling predictions and assessments of future flood impacts and map vegetation structure on a global scale and monitor its changes due to such processes as fire, volcanic eruption and deforestation. With the availability of SAR images in near real - time from multiple satellites in the near future, the fusion of SAR images with other images and data is playing an increasingly important role in understanding and forecasting natural hazards.

  17. Space Radar Image of Cape Cod, Massachusetts

    NASA Technical Reports Server (NTRS)

    1994-01-01

    This spaceborne radar image shows the famous 'hook' of Cape Cod, Massachusetts. The Cape, which juts out into the Atlantic Ocean about 100 kilometers (62 miles) southeast of Boston, actually consists of sandy debris left behind by the great continental ice sheets when they last retreated from southern New England about 20,000 years ago. Today's landscape consists of sandy forests, fields of scrub oak and other bushes and grasses, salt marshes, freshwater ponds, as well as the famous beaches and sand dunes. In this image, thickly forested areas appear green, marshes are dark blue, ponds and sandy areas are black, and developed areas are mostly pink. The dark L-shape in the lower center is the airport runways in Hyannis, the Cape's largest town. The dark X-shape left of the center is Otis Air Force Base. The Cape Cod Canal, above and left of center, connects Buzzards Bay on the left with Cape Cod Bay on the right. The northern tip of the island of Martha's Vineyard is seen in the lower left. The tip of the Cape, in the upper right, includes the community of Provincetown, which appears pink, and the protected National Seashore areas of sand dunes that parallel the Atlantic coast east of Provincetown. Scientists are using radar images like this one to study delicate coastal environments and the effects of human activities on the ecosystem and landscape. This image was acquired by Spaceborne Imaging Radar-C/X-band Synthetic Aperture Radar (SIR-C/X-SAR) onboard the space shuttle Endeavour on April 15, 1994. The image is 81.7 kilometers by 43.1 kilometers (50.7 miles by 26.7 miles) and is centered at 41.8 degrees north latitude, 70.3 degrees west 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, horizontally transmitted and received; green is C-band, horizontally transmitted, vertically received; and blue is C-band, horizontally 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 program.

  18. 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's Mission to Planet Earth program.

  19. Spaceborne radar subsurface imaging in hyperarid regions

    NASA Technical Reports Server (NTRS)

    Elachi, C.; Roth, L. E.; Schaber, G. G.

    1984-01-01

    Imaging data acquired with the Shuttle Imaging Radar (SIR-A) over the hyperarid region of Egypt/Sudan clearly show surface penetration through the sand cover. Even though absorption does occur in the sand layer, surface refraction leads to a steeper incidence angle at the sand/bedrock interface resulting in a stronger backscatter. A simple backscatter model shows that for a low-loss thin sand layer the presence of the covering layer enhances the capability to image the subsurface interface, particularly at large incidence angles and HH polarization.

  20. Space Radar Image of Colorado River

    NASA Technical Reports Server (NTRS)

    1994-01-01

    This space radar image illustrates the recent rapid urban development occurring along the lower Colorado River at the Nevada/Arizona state line. Lake Mojave is the dark feature that occupies the river valley in the upper half of the image. The lake is actually a reservoir created behind Davis Dam, the bright white line spanning the river near the center of the image. The dam, completed in 1953, is used both for generating electric power and regulating the river's flow downstream. Straddling the river south of Davis Dam, shown in white and bright green, are the cities of Laughlin, Nevada (west of the river) and Bullhead City, Arizona (east of the river). The runway of the Laughlin, Bullhead City Airport is visible as a dark strip just east of Bullhead City. The area has experienced rapid growth associated with the gambling industry in Laughlin and on the Fort Mojave Indian Reservation to the south. The community of Riviera is the bright green area in a large bend of the river in the lower left part of the image. Complex drainage patterns and canyons are the dark lines seen throughout the image. Radar is a useful tool for studying these patterns because of the instrument's sensitivity to roughness, vegetation and subtle topographic differences. This image is 50 kilometers by 35 kilometers (31 miles by 22 miles) and is centered at 35.25 degrees north latitude, 114.67 degrees west longitude. North is toward the upper right. The colors are assigned to different radar frequencies and polarizations as follows: red is L-band, horizontally transmitted and received; green is L-band, horizontally transmitted and vertically received; and blue is C-band, horizontally transmitted and vertically received. The image was acquired by the Spaceborne Imaging Radar-C/X-band Synthetic Aperture Radar (SIR-C/X-SAR) on April 13, 1994, onboard the space shuttle Endeavour. SIR-C/X-SAR, a joint mission of the German, Italian and United States space agencies, is part of NASA's Office of Mission to Planet Earth.

  1. The 94 GHz MMW imaging radar system

    NASA Technical Reports Server (NTRS)

    Alon, Yair; Ulmer, Lon

    1993-01-01

    The 94 GHz MMW airborne radar system that provides a runway image in adverse weather conditions is now undergoing tests at Wright-Patterson Air Force Base (WPAFB). This system, which consists of a solid state FMCW transceiver, antenna, and digital signal processor, has an update rate of 10 times per second, 0.35x azimuth resolution and up to 3.5 meter range resolution. The radar B scope (range versus azimuth) image, once converted to C scope (elevation versus azimuth), is compatible with the standard TV presentation and can be displayed on the Head Up Display (HUD) or Head Down Display (HDD) to aid the pilot during landing and takeoff in limited visibility conditions.

  2. Radar E-O image fusion

    NASA Technical Reports Server (NTRS)

    Oneil, William F.

    1993-01-01

    The fusion of radar and electro-optic (E-O) sensor images presents unique challenges. The two sensors measure different properties of the real three-dimensional (3-D) world. Forming the sensor outputs into a common format does not mask these differences. In this paper, the conditions under which fusion of the two sensor signals is possible are explored. The program currently planned to investigate this problem is briefly discussed.

  3. Space Radar Image of Vesuvius, Italy

    NASA Technical Reports Server (NTRS)

    1994-01-01

    Mt. Vesuvius, one of the best known volcanoes in the world primarily for the eruption that buried the Roman city of Pompeii, is shown in the center of this radar image. The central cone of Vesuvius is the dark purple feature in the center of the volcano. This cone is surrounded on the northern and eastern sides by the old crater rim, called Mt. Somma. Recent lava flows are the pale yellow areas on the southern and western sides of the cone. Vesuvius is part of a large volcanic zone which includes the Phalagrean Fields, the cluster of craters seen along the left side of the image. The Bay of Naples, on the left side of the image, is separated from the Gulf of Salerno, in the lower left, by the Sorrento Peninsula. Dense urban settlement can be seen around the volcano. The city of Naples is above and to the left of Vesuvius; the seaport of the city can be seen in the top of the bay. Pompeii is located just below the volcano on this image. The rapid eruption in 79 A.D. buried the victims and buildings of Pompeii under several meters of debris and killed more than 2,000 people. Due to the violent eruptive style and proximity to populated areas, Vesuvius has been named by the international scientific community as one of fifteen Decade Volcanoes which are being intensively studied during the 1990s. The image is centered at 40.83 degrees North latitude, 14.53 degrees East longitude. It shows an area 100 kilometers by 55 kilometers (62 miles by 34 miles.) This image was acquired on April 15, 1994 by the Spaceborne Imaging Radar-C/X-Band Synthetic Aperture Radar (SIR-C/X-SAR) aboard the Space Shuttle Endeavour. 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. Processing for spaceborne synthetic aperture radar imagery

    NASA Technical Reports Server (NTRS)

    Lybanon, M.

    1973-01-01

    The data handling and processing in using synthetic aperture radar as a satellite-borne earth resources remote sensor is considered. The discussion covers the nature of the problem, the theory, both conventional and potential advanced processing techniques, and a complete computer simulation. It is shown that digital processing is a real possibility and suggests some future directions for research.

  5. Synthetic aperture radar and digital processing: An introduction

    NASA Technical Reports Server (NTRS)

    Dicenzo, A.

    1981-01-01

    A tutorial on synthetic aperture radar (SAR) is presented with emphasis on digital data collection and processing. Background information on waveform frequency and phase notation, mixing, Q conversion, sampling and cross correlation operations is included for clarity. The fate of a SAR signal from transmission to processed image is traced in detail, using the model of a single bright point target against a dark background. Some of the principal problems connected with SAR processing are also discussed.

  6. Space radar image of Mississippi River

    NASA Technical Reports Server (NTRS)

    1995-01-01

    This image of the Mississippi River in Mississippi, Arkansas, and Louisiana shows regions of the southern United States that are prone to flooding. Data acquired by the Spaceborne Imaging Radar-C/X-band Synthetic Aperture imaging radar system, which flew on two space shuttle missions in April and October 1994, can help scientists assess flooding potentials and improve land management for future agricultural development. This image was acquired on October 9, 1994, during orbit 151 of the space shuttle Endeavour. The image is centered at about 32.75 degrees north latitude and 90.5 degrees west longitude and covers an area of about 23 kilometers by 40 kilometers (14.2 miles by 24.8 miles). North is toward the upper right of the image. The different colors represent the data return in different radar channels: red is L-band, vertically transmitted and received; green is L-band vertically transmitted and horizontally received; and blue is C-band vertically transmitted and received. This site along the Mississippi River lies north of Vicksburg along the Arkansas-Louisiana-Mississippi state borders. The river marks the stateline. Louisiana and Arkansas lie above the river and Mississippi is below the river. This region is characterized by rich farmland where a variety of crops are grown. The town located in the extreme upper left hand corner is Eudora, Arkansas. The long, narrow lakes which lie roughly parallel to the river are called oxbow lakes, named for the U-shaped harness worn by an ox. Oxbows are formed when a river changes course, abandoning old channels in favor of a new course. As the river changes course, the surrounding land dries out, leaving these lakes isolated. Oxbow lakes are common in areas where rivers flow through generally flat terrain, allowing the river to easily change course. The green regions bordering the river are undeveloped forested areas

  7. Space Radar Image of Manaus region of Brazil

    NASA Technical Reports Server (NTRS)

    1994-01-01

    These L-band images of the Manaus region of Brazil were acquired by the Spaceborne Imaging Radar-C and X-band Synthetic Aperture Radar (SIR-C/X-SAR) aboard the space shuttle Endeavour. The left image was acquired on April 12, 1994, and the middle image was acquired on October 3, 1994. The area shown is approximately 8 kilometers by 40 kilometers (5 miles by 25 miles). The two large rivers in this image, the Rio Negro (top) and the Rio Solimoes (bottom), combine at Manaus (west of the image) to form the Amazon River. The image is centered at about 3 degrees south latitude and 61 degrees west longitude. North is toward the top left of the images. The differences in brightness between the images reflect changes in the scattering of the radar channel. In this case, the changes are indicative of flooding. A flooded forest has a higher backscatter at L-band (horizontally transmitted and received) than an unflooded river. The extent of the flooding is much greater in the April image than in the October image, and corresponds to the annual, 10-meter (33-foot) rise and fall of the Amazon River. A third image at right shows the change in the April and October images and was created by determining which areas had significant decreases in the intensity of radar returns. These areas, which appear blue on the third image at right, show the dramatic decrease in the extent of flooded forest, as the level of the Amazon River falls. The flooded forest is a vital habitat for fish and floating meadows are an important source of atmospheric methane. This demonstrates the capability of SIR-C/X-SAR to study important environmental changes that are impossible to see with optical sensors over regions such as the Amazon, where frequent cloud cover and dense forest canopies obscure monitoring of floods. Field studies by boat, on foot and in low-flying aircraft by the University of California at Santa Barbara, in collaboration with Brazil's Instituto Nacional de Pesguisas Estaciais, during the first and second flights of the SIR-C/X-SAR system have validated the interpretation of the radar images. 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 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.

  8. Space Radar Image of Niya ruins, Taklamakan desert

    NASA Technical Reports Server (NTRS)

    1999-01-01

    This radar image is of an area thought to contain the ruins of the ancient settlement of Niya. It is located in the southwestern corner of the Taklamakan Desert in China's Sinjiang Province. This oasis was part of the famous Silk Road, an ancient trade route from one of China's earliest capitols, Xian, to the West. The image shows a white linear feature trending diagonally from the upper left to the lower right. Scientists believe this newly discovered feature is a man-made canal which presumably diverted river waters toward the settlement of Niya for irrigation purposes. The 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 106th orbit on April 16, 1994, and is centered at 37.78 degrees north latitude and 82.41 degrees east longitude. The false-color radar image was created by displaying the C-band (horizontally transmitted and received) return in red, the L-band (horizontally transmitted and received) return in green, and the L-band (horizontally transmitted and vertically received) return in blue. Areas in mottled white and purple are low-lying floodplains of the Niya River. Dark green and black areas between river courses are higher ridges or dunes confining the water flow. 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: the 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 Forschungsanstaltfuer Luft und Raumfahrt e.v.(DLR), the major partner in science, operations and data processing of X-SAR.

  9. Space Radar Image of Lisbon, Portugal

    NASA Technical Reports Server (NTRS)

    1994-01-01

    This radar image of Lisbon, Portugal illustrates the different land use patterns that are present in coastal Portugal. Lisbon, the national capital, lies on the north bank of the Rio Tejo where the river enters the Atlantic Ocean. The city center appears as the bright area in the center of the image. The green area west of the city center is a large city park called the Parque Florestal de Monsanto. The Lisbon Airport is visible east of the city. The Rio Tejo forms a large bay just east of the city. Many agricultural fields are visible as a patchwork pattern east of the bay. Suburban housing can be seen on the southern bank of the river. Spanning the river is the Ponte 25 de Abril, a large suspension bridge similar in architecture to San Francisco's Golden Gate Bridge. The image was acquired on April 19, 1994 and is centered at 38.8 degrees north latitude, 9.2 degrees west longitude. North is towards the upper right. The image is 50 kilometers by 30 kilometers (31 miles by 19 miles). The colors in this image represent the following radar channels and polarizations: red is L-band, horizontally transmitted and received; green is L-band, horizontally transmitted and 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.

  10. Space Radar Image of Safsaf, North Africa

    NASA Technical Reports Server (NTRS)

    1999-01-01

    This is a false-color image of the uninhabited Safsaf Oasis in southern Egypt near the Egypt/Sudan border. It was produced from data obtained from the L-band and C-band radars that are part of the Spaceborne Imaging Radar C/X-Band Synthetic Aperture Radar (SIR-C/X-SAR) onboard space shuttle Endeavour on April 9, 1994. The image is centered at 22 degree north latitude, 29 degrees east longitude. It shows detailed structures of bedrock; the dark blue sinuous lines are braided channels that occupy part of an old broad river valley. On the ground and in optical photographs, this big valley and the channels in it are invisible because they are entirely covered by windblown sand. Some of these same channels were observed in SIR-A images in 1981. It is hypothesized that the large valley was carved by one of several ancient predecessor rivers that crossed this part of North Africa, flowing westward, tens of millions of years before the Nile River existed. The Nile flows north about 300 kilometers (200 miles) to the east. The small channels are younger, and probably formed during relatively wet climatic periods within the past few hundred thousand years. This image shows that the channels are in a river valley located in an area where U.S. Geological Survey geologists and archeologists discovered an unusual concentration of hand axes (stone tools) used by Early Man (Homo erectus) hundreds of thousands of years ago. The image clearly shows that in wetter times, the valley would have supported game animals and vegetation. Today, as a result of climate change, the area in uninhabited and lacks water except fora few scattered oases. This color composite image was produced from C-band and L-band horizontal polarization images. The C-band image was assigned red, the L-band (HH) polarization image is shown in green, and the ratio of these two images (LHH/CHH) appears in blue. The primary and composite colors on the image indicate the degree to which the C-band, H-band, their ratio --or some combination of all three -- respond to the roughness of the radar backscattering surface. Using this coloring scheme, areas that appear bright at both L-band and C-band are colored yellow, while areas that appear brighter at L-band than C-band appear more blue. Detailed analysis of this scene indicates that the separate C-band and L-band images used to produce this color composite have a very similar overall appearance. This suggests that the C-band and the L-band signals are both easily penetrating the thin 1- to 12-centimeter (0.5- to 5-inch) 'average' surface cover of loose windblown sand, and are commonly 'seeing' similar interfaces just below that cover. This radar interface may be at the scattered rocky outcrops on the ground surface, but is more likely to be the shallow underlying surfaces of river gravel or bedrock, which are generally covered by only a few inches of windblown sand. Virtually everything visible on this radar composite image cannot be seen, either when standing on the ground or when viewing photographs or satellite images such as the United States' Landsat or the French SPOT satellite. 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, Ag

  11. Multi-static Synthetic Aperture Radar Image Formation

    E-print Network

    Yazici, Birsen

    -static radar are less effective against distributed radar systems [3], [4]. Finally, multi-static measurementsMulti-static Synthetic Aperture Radar Image Formation V. P. Krishnan Department of Electrical, Systems and Computer Engineering Rensselaer Polytechnic Institute 110 8th Street, Troy, NY 12180 Email

  12. Imaging radar observations of directional properties of ocean waves

    NASA Astrophysics Data System (ADS)

    McLeish, William; Ross, Duncan B.

    1983-05-01

    SEASAT-A synthetic aperture radar (SAR) and side-looking airborne radar (SLAR) images of ocean waves are examined in the form of normalized directional distributions of backscatter variance at series of frequencies. This method provides a more detailed description of radar results than have contoured two-dimensional wave number spectra and reduces some of the uncertainties in relating radar measurements to the waves. The range of aspects of the radar distribution that parallel those of ocean waves is defined. Within this restriction, not only can dominant wave frequencies and directions be determined accurately, but also the shape of a directional peak at a frequency, its directional width, and the background level can be determined approximately. Some of these aspects are examined with SLAR images obtained near reference wave measurements. Through its superior directional resolution, the radar appears to have distinguished two wave trains at a single frequency only 20° different in direction. The SEASAT-A satellite SAR provided an unusual opportunity to examine directional properties of waves in the hostile environment about Hurricane Fico. A swell highly dispersed in frequency and direction at a distance from the center of 450 km had a minimum observed directional width of 11°. Wave directions, their changes with frequency, and directional widths were in accord with those expected from the hurricane winds. Thematic maps of the direction and width of the swell energy as it spread across the ocean surface show smooth changes in these properties over distance, with relatively small scatter of individual values. These patterns also are in accord with those from a simple hurricane wave emission concept, but details of the distributions show distinct departures that must represent unrecognized smaller-scale fluctuations of the process.

  13. Optical signal processing of phased array radar

    NASA Astrophysics Data System (ADS)

    Weverka, Robert T.

    This thesis develops optical processors that scale to very high processing speed. Optical signal processing is often promoted on the basis of smaller size, lower weight and lower power consumption as well as higher signal processing speed. While each of these requirements has applications, it is the ones that require processing speed beyond that available in electronics that are most compelling. Thirty years ago, optical processing was the only method fast enough to process Synthetic Aperture Radar (SAR), one of the more demanding signal processing tasks at this time. Since that time electronic processing speed has improved sufficiently to tackle that problem. We have sought out the problems that require significantly higher processing speed and developed optical processors that tackle these more difficult problems. The components that contribute to high signal processing speed are high input signal bandwidth, a large number of parallel input channels each with this high bandwidth, and a large number of parallel operations required on each input channel. Adaptive signal processing for phased array radar has all of these factors. The processors developed for this task scale well in three dimensions, which allows them to maximize parallelism for high speed. This thesis explores an example of a negative feedback adaptive phased array processor and an example of a positive feedback phased array processor. The negative feedback processor uses and array of inputs in up to two dimensions together with the time history of the signal in the third dimension to adapt the array pattern to null out incoming jammer signals. The positive feedback processor uses the incoming signals and assumptions about the radar scene to correct for position errors in a phased array. Discovery and analysis of these new processors are facilitated by an original volume holographic analysis technique developed in the thesis. The thesis includes a new acoustooptic Bragg cell geometry developed with this analysis technique. This Bragg cell provides a low insertion delay making it suitable for the feedback phased array radar systems. This thesis develops a new algorithm for phased array radar processing. This adaptation of the Widrow algorithm requires fewer delay lines allowing us to implement a system that can scale to dense two-dimensional phased array radar. The thesis explores this processor in depth, developing the description of the system evolution, the nonlinear dynamics governing the system and the dynamic range: that can be achieved. The system behavior and dynamics are confirmed experimentally. Finally this thesis explores positive feed back architectures for the phased radar problem posed by Steinberg in which the array itself is poorly surveyed. To our knowledge, optical signal processing solutions to this problem have not been developed prior to this work.

  14. Golay Complementary Waveforms for Sparse Delay-Doppler Radar Imaging

    E-print Network

    Pezeshki, Ali

    Golay Complementary Waveforms for Sparse Delay-Doppler Radar Imaging Yuejie Chi , Robert Calderbank, CO 80523, USA Abstract--We present a new approach to radar imaging that exploits sparsity in the matched filter domain to enable high resolution imaging of targets in delay and Doppler. We show

  15. Space Radar Image of Namib Desert in Southern Namib

    NASA Technical Reports Server (NTRS)

    1999-01-01

    This is a C-band, VV polarization radar image of the Namib desert in southern Namibia, near the coast of South West Africa. The image is centered at about 25 degrees South latitude, 15.5 degrees East longitude. This image was one of the first acquired by the Spaceborne Imaging Radar-C/X-Band Synthetic Aperture Radar (SIR-C/X-SAR) when it was taken on orbit 4 from the shuttle Endeavour on April 9, 1994. The area shown is approximately 78 kilometers by 20 kilometers. The dominant features in the image are complex sand dune patterns formed by the prevailing winds in this part of the Namib desert. The Namib desert is an extremely dry area formed largely because of the influence of the cold Benguela ocean current that flows northward along the coast of Namibia. The bright areas at the bottom of the image are exposed outcrops of Precambrian rocks. This extremely barren area is a region rich in diamonds that through the centuries have washed down from the mountains. The town of Luderitz is located just to the south of the area shown. 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 Aumfahrtangelegenheiten (DARA), and the Italian space agency, Agenzia Spaziale Italiana (ASI), with the Deutsche Forschungsanstaltfuer Luft und Raumfahrt e.v. (DLR), he major partner in science, operations and data processing of X-SAR.

  16. Meteor radar signal processing and error analysis

    NASA Astrophysics Data System (ADS)

    Kang, Chunmei

    Meteor wind radar systems are a powerful tool for study of the horizontal wind field in the mesosphere and lower thermosphere (MLT). While such systems have been operated for many years, virtually no literature has focused on radar system error analysis. The instrumental error may prevent scientists from getting correct conclusions on geophysical variability. The radar system instrumental error comes from different sources, including hardware, software, algorithms and etc. Radar signal processing plays an important role in radar system and advanced signal processing algorithms may dramatically reduce the radar system errors. In this dissertation, radar system error propagation is analyzed and several advanced signal processing algorithms are proposed to optimize the performance of radar system without increasing the instrument costs. The first part of this dissertation is the development of a time-frequency waveform detector, which is invariant to noise level and stable to a wide range of decay rates. This detector is proposed to discriminate the underdense meteor echoes from the background white Gaussian noise. The performance of this detector is examined using Monte Carlo simulations. The resulting probability of detection is shown to outperform the often used power and energy detectors for the same probability of false alarm. Secondly, estimators to determine the Doppler shift, the decay rate and direction of arrival (DOA) of meteors are proposed and evaluated. The performance of these estimators is compared with the analytically derived Cramer-Rao bound (CRB). The results show that the fast maximum likelihood (FML) estimator for determination of the Doppler shift and decay rate and the spatial spectral method for determination of the DOAs perform best among the estimators commonly used on other radar systems. For most cases, the mean square error (MSE) of the estimator meets the CRB above a 10dB SNR. Thus meteor echoes with an estimated SNR below 10dB are discarded due to the potential of producing a biased estimate. The precision of the estimated parameters can then be computed using their CRB values as a proxy for the estimated variance. These errors propagate to form the instrumental errors on the height and horizontal wind measurements. Thirdly, the interferometer configuration of interferometric meteor radar system is studied. The interferometer uses the phase differences measured at different sensor pairs to determine the DOA of the meteor trail. Typically Jones cross is used in most of current meteor radar systems, such as MEDAC and SKYiMet. We have evaluated this configuration with other array geometries,such as 'T', 'L' and circular array to examine their performance on the precision of the DOA estimates. The results show that 'T' array has an overall better CRB than other geometries, while with the yagi antenna pattern as a course determination of the DOA range, the circular array performs the best with the lowest sidelobes on the spatial spectral. A Matlab based planar array design package designed for determination and visualization of the DOA estimation performance for a user designed antenna array was developed. Fourthly, based on the special configuration of the South Pole COBRA system, a low cost computational phase calibration method is proposed. Accurate knowledge of the receiver phase ofsets is another factor that can affect system performance. Lastly, the postprocessing results of the meteor echoes collected during 2005 from the South Pole COBRA system are presented. This radar system is shown to have a precision of 2m/s in the horizontal winds, an azimuth precision of 1o, and an elevation precision of 3o. Preliminary scientific results are presented to verify the effectiveness of our processing scheme, and include the seasonal variation of meteor rates as a function of height, and the vertical structure of large semidiurnal tide observed over the South Pole austral summer. The processing schemes and error analysis methods presented in this dissertation can be easily extended to other meteor radar

  17. High-resolution planetary imaging via spotlight-mode synthetic aperture radar.

    PubMed

    Webb, J H; Munson, D R; Stacy, N S

    1998-01-01

    We consider the application of a spotlight-mode synthetic aperture radar (SAR) imaging technique to the problem of high-resolution lunar imaging and other related radar astronomy problems. This approach offers improved image quality, compared with conventional processing, at the expense of slightly increased computational effort. Results of the processing of lunar data acquired with the 12.6 cm wavelength radar system at Arecibo Observatory are presented, and compared with the best available published result, by Stacy (1993), which uses focusing techniques from stripmap SAR. PMID:18276222

  18. SPace Radar Image of Mt. Pinatubo, Philippines

    NASA Technical Reports Server (NTRS)

    1999-01-01

    This is a false color L-band and C-band image of the area around Mount Pinatubo in the Philippines, centered at about 15 degrees north latitude, 120.5 degrees east longitude. 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 orbit 78 on April 13, 1994. The false-color composite is made by displaying the L-band HH return in red, the L-band HV return in green and the C-band HV return in blue. The area shown is approximately 45 by 68 kilometers (28 by 42 miles). The main volcanic crater on Mount Pinatubo produced by the June 1991 eruptions, and the steep slopes on the upper flanks of the volcano, are easily seen in this image. The red color on the high slopes show the rougher ash deposited during the 1991 eruption. The dark drainages are the smooth mudflows which continue to flood the river valleys after heavy rain. Radar images such as this one can be used to identify the areas flooded by mudflows, which are difficult to distinguish visually, and to assess the rate at which the erosion and deposition continues. A key aspect of the second SIR-C/X-SAR mission in August 1994 will be to collect a second image of Pinatubo during the summer monsoon season -- new mudflows will have occurred -- and to evaluate the short-term changes. The 1991 eruption of Mount Pinatubo in the Philippines is well known for its near-global effects on the atmosphere and climate due to the large amount of sulfur dioxide that was injected into the upper atmosphere. What is less widely known is that even today the volcano continues to be a major hazard to the people who have returned to the area around the volcano. Dangerous mudflows (called 'lahars') are often generated by heavy rains, and these can still sweep down river valleys and wash out roads and villages, or bury low lying areas in several meters of mud and volcanic debris. These mudflows will continue to be a severe hazard around Pinatubo for the next 10 to 15 years. 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).

  19. Space Radar Image of Rabaul Volcano, New Guinea

    NASA Technical Reports Server (NTRS)

    1994-01-01

    This is a radar image of the Rabaul volcano on the island of New Britain, Papua, New Guinea taken almost a month after its September 19, 1994, eruption that killed five people and covered the town of Rabaul and nearby villages with up to 75 centimeters (30 inches) of ash. More than 53,000 people have been displaced by the eruption. 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 173rd orbit on October 11, 1994. This image is centered at 4.2 degrees south latitude and 152.2 degrees east longitude in the southwest Pacific Ocean. The area shown is approximately 21 kilometers by 25 kilometers (13 miles by 15.5 miles). North is toward the upper right. 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 and vertically received); blue represents the C-band (horizontally transmitted and vertically received). Most of the Rabaul volcano is underwater and the caldera (crater) creates Blanche Bay, the semi-circular body of water that occupies most of the center of the image. Volcanic vents within the caldera are visible in the image and include Vulcan, on a peninsula on the west side of the bay, and Rabalanakaia and Tavurvur (the circular purple feature near the mouth of the bay) on the east side. Both Vulcan and Tavurvur were active during the 1994 eruption. Ash deposits appear red-orange on the image, and are most prominent on the south flanks of Vulcan and north and northwest of Tavurvur. A faint blue patch in the water in the center of the image is a large raft of floating pumice fragments that were ejected from Vulcan during the eruption and clog the inner bay. Visible on the east side of the bay are the grid-like patterns of the streets of Rabaul and an airstrip, which appears as a dark northwest-trending band at the right-center of the image. Ashfall and subsequent rains caused the collapse of most buildings in the town of Rabaul. Mudflows and flooding continue to pose serious threats to the town and surrounding villages. Volcanologists and local authorities expect to use data such as this radar image to assist them in identifying the mechanisms of the eruption and future hazardous conditions that may be associated with the vigorously active volcano. Spaceborne Imaging Radar-C/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 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.

  20. Earth resources shuttle imaging radar. [systems analysis and design analysis of pulse radar for earth resources information system

    NASA Technical Reports Server (NTRS)

    1975-01-01

    A report is presented on a preliminary design of a Synthetic Array Radar (SAR) intended for experimental use with the space shuttle program. The radar is called Earth Resources Shuttle Imaging Radar (ERSIR). Its primary purpose is to determine the usefulness of SAR in monitoring and managing earth resources. The design of the ERSIR, along with tradeoffs made during its evolution is discussed. The ERSIR consists of a flight sensor for collecting the raw radar data and a ground sensor used both for reducing these radar data to images and for extracting earth resources information from the data. The flight sensor consists of two high powered coherent, pulse radars, one that operates at L and the other at X-band. Radar data, recorded on tape can be either transmitted via a digital data link to a ground terminal or the tape can be delivered to the ground station after the shuttle lands. A description of data processing equipment and display devices is given.

  1. Transceiver array development for submillimeter-wave imaging radars

    NASA Astrophysics Data System (ADS)

    Cooper, Ken B.; Reck, Theodore A.; Jung-Kubiak, Cecile; Lee, Choonsup; Siles, Jose V.; Lin, Robert H.; Peralta, Alejandro; Decrossas, Emmanuel; Schlecht, Erich T.; Chattopadhyay, Goutam; Mehdi, Imran

    2013-05-01

    The Jet Propulsion Laboratory (JPL) is developing compact transceiver arrays housing discrete GaAs Schottky diodes with integrated waveguides in order to increase the frame rate and lower the cost of active submillimeter-wave imaging radar systems. As part of this effort, high performance diode frequency multiplier and mixer devices optimized for a 30 GHz bandwidth centered near 340 GHz have been fabricated using JPL's MoMeD process. A two-element array unit cell was designed using a layered architecture with three-dimensional waveguide routing for maximum scalability to multiple array elements. Prototype two-element arrays have been built using both conventionally machined metal blocks as well as gold-plated micromachined silicon substrates. Preliminary performance characterization has been accomplished in terms of transmit power, and conversion loss, and promising 3D radar images of concealed weapons have been acquired using the array.

  2. 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.

  3. Micro-Doppler processing for ultra-wideband radar data

    NASA Astrophysics Data System (ADS)

    Smith, Graeme E.; Ahmad, Fauzia; Amin, Moeness G.

    2012-06-01

    In this paper, we describe an operational pulse Doppler radar imaging system for indoor target localization and classification, and show how a target's micro-Doppler signature (?DS) can be processed when ultra-wideband (UWB) waveforms are employed. Unlike narrowband radars where time-frequency signal representations can be applied to reveal the target time-Doppler frequency signatures, the UWB system permits joint range-time-frequency representation (JRTFR). JRTFR outputs the data in a 3D domain representing range, frequency, and time, allowing both the ?DS and high range resolution (HRR) signatures to be observed. We delineate the relationship between the ?DS and the HRR signature, showing how they would form a complimentary joint feature for classification. We use real-data to demonstrate the effectiveness of the UWB pulse-Doppler radar, combined with nonstationary signal analyses, in gaining valuable insights into human positioning and motions.

  4. An Approach to Ground Moving Target Indication Using Multiple Resolutions of Multilook Synthetic Aperture Radar Images

    E-print Network

    Akers, Geoffrey

    2009-12-15

    Ground moving target indication (GMTI) using multiple resolutions of synthetic aperture radar (SAR) images to estimate the clutter scattering statistics is shown to outperform conventional sample matrix inversion space-time adaptive processing GMTI...

  5. Semisupervised synthetic aperture radar image segmentation with multilayer superpixels

    NASA Astrophysics Data System (ADS)

    Wang, Can; Su, Weimin; Gu, Hong; Gong, Dachen

    2015-01-01

    Image segmentation plays a significant role in synthetic aperture radar (SAR) image processing. However, SAR image segmentation is challenging due to speckle. We propose a semisupervised bipartite graph method for segmentation of an SAR image. First, the multilayer over-segmentation of the SAR image, referred to as superpixels, is computed using existing segmentation algorithms. Second, an unbalanced bipartite graph is constructed in which the correlation between pixels is replaced by the texture similarity between superpixels, to reduce the dimension of the edge matrix. To also improve efficiency, we define a new method, called the combination of the Manhattan distance and symmetric Kullback-Leibler divergence, to measure texture similarity. Third, by the Moore-Penrose inverse matrix and semisupervised learning, we construct an across-affinity matrix. A quantitative evaluation using SAR images shows that the new algorithm produces significantly high-quality segmentations as compared with state-of-the-art segmentation algorithms.

  6. Space radar image of Sunbury, Pennsylvania

    NASA Technical Reports Server (NTRS)

    1995-01-01

    Scientists are using this radar image of the area surrounding Sunbury, Pennsylvania to study the geologic structure and land use patterns in the Appalachian Valley and Ridge province. This image was collected on October 6, 1994 by the Spaceborne Imaging Radar-C/ X-Band Synthetic Aperture Radar (SIR-C/X-SAR) on orbit 102 of the space shuttle Endeavour. The image is centered on latitude 40.85 degrees North latitude and 76.79 degrees West longitude. The area shown is approximately 30.5 km by 38 km.(19 miles by 24 miles). North is towards the upper right of the image. The Valley and Ridge province occurs in the north-central Appalachians, primarily in Pennsylvania, Maryland, and Virginia. It is an area of adjacent valleys and ridges that formed when the Appalachian mountain were created some 370 to 390 million years ago. During the continental collision that formed the Appalachians, the rocks in this area were pushed from the side and buckled much like a rug when pushed from one end. Subsequent erosion has produced the landscape we see in this image. The more resistant rocks, such as sandstone, form the tops of the ridges which appear as forested greenish areas on this image. The less resistant rocks, such as limestone, form the lower valleys which are cleared land and farm fields and are purple in this image. Smaller rivers and streams in the area flow along the valleys and in places cut across the ridges in 'water gaps.' In addition to defining the geography of this region, the Valley and Ridge province also provides this area with natural resources. The valleys provide fertile farmland and the folded mountains form natural traps for oil and gas accumulation; coal deposits are also found in the mountains. The colors in the image are assigned to different frequencies and polarizations of the SIR-C radar as follows: red is L-band horizontally transmitted, horizontally received; green is L-band horizontally transmitted, vertically received; blue is C-band horizontally transmitted, horizontally received. The river junction near the top of the image is where the West Branch River flows into the Susquehanna River, which then flows to the south-southwest past the state capitol of Harrisburg, 70 km (43 miles) to the south and not visible in this image. The town of Sunbury is shown along the Susquehanna on the east just to the southeast of the junction with West Branch. Three structures that cross the Susquehanna; the northern and southern of these structures are bridges and middle structure is the Shamokin Dam which confines the Susquehanna just south of the junction with West Branch. The prominent S-shaped mountain ridge in the center of the image is, from north to south, Little Mountain (the top of the S), Line Mountain (the middle of the S), and Mahantango Mountain (the bottom of the S).

  7. Computational ghost imaging versus imaging laser radar for three-dimensional imaging

    E-print Network

    Hardy, Nicholas David

    Ghost imaging has been receiving increasing interest for possible use as a remote-sensing system. There has been little comparison, however, between ghost imaging and the imaging laser radars with which it would be competing. ...

  8. Imaging radar polarimetry - A status report

    NASA Technical Reports Server (NTRS)

    Held, Daniel N.

    1987-01-01

    The development of imaging radar polarimetry at JPL is considered. Advances in the correlation of polarimetric SAR and in the synthesis of arbitrary polarization are discussed. The capabilities of the polarization workstation are described. Various applications for polarimetric SAR data include: the identification of scatter, the evaluation of scattering theories, the measurement of the roughness of geologic targets, the classification of forest stands, and the characterization of trees within a particular stand. The development and testing of the DC-8 SAR and the SIR-C system are examined.

  9. Space Radar Image of Prince Albert, Canada

    NASA Technical Reports Server (NTRS)

    1999-01-01

    This is a false-color composite of Prince Albert, Canada, centered at 53.91 north latitude and 104.69 west longitude. This image was acquired by the Spaceborne Imaging Radar C/X-Band Synthetic Aperture Radar(SIR-C/X-SAR) aboard space shuttle Endeavour on its 20th orbit. The area is located 40 kilometers (25 miles) north and 30 kilometers (20 miles) east of the town of Prince Albert in the Saskatchewan province of Canada. The image covers the area east of the Candle lake, between gravel surface highways 120 and 106 and west of 106. The area in the middle of the image covers the entire Nipawin (Narrow Hills) provincial park. The look angle of the radar is 30 degrees and the size of the image is approximately 20 kilometers by 50 kilometers (12 by 30 miles). The image was produced by using only the L-band. The three polarization channels HH, HV and VV are illustrated by red, green and blue respectively. The changes in the intensity of each color are related to various surface conditions such as variations in forest stands, frozen or thawed condition of the surface, disturbances (fire and deforestation), and areas of regrowth. Most of the dark areas in the image are the ice-covered lakes in the region. The dark area on the top right corner of the image is the white Gull Lake north of the intersection of highway 120 and 913. The right middle part of the image shows Lake Ispuchaw and Lower Fishing Lake. The deforested areas are also shown by dark areas in the image. Since most of the logging practice at the Prince Albert area is around the major highways, the deforested areas can be easily detected as small geometrically shaped dark regions along the roads. At the time of the SIR-C/X-SAR overpass a major part of the forest is either frozen or undergoing the spring thaw. The L-band HH shows a high return in the jack pine forest. The reddish areas in the image are old jack pine forest, 12 to 17 meters (40to 55 feet) in height and 60 to 75 years old. The orange-greenish areas are young jack pine trees, 3 to 5 meters (10 to 16 feet) in height and 11 to 16 years old. The green areas are due to the relative high intensity of the HV channel which is strongly correlated with the amount of biomass. L-band HV channel shows the biomass variations over the entire region. Most of the green areas, when compared to the forest cover maps are identified as black spruce trees. The dark blue and dark purple colors show recently harvested or regrowth areas respectively. 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).

  10. Space Radar Image of Missouri River, Glasgow, Missouri

    NASA Technical Reports Server (NTRS)

    1994-01-01

    This is a false-color L-band image of an area near Glasgow, Missouri, centered at about 39.2 degrees north latitude and 92.8 degrees west longitude. The 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 50th orbit on October 3, 1994. The false-color composite was made by displaying the L-band (horizontally transmitted and received) return in red; the L-band (horizontally transmitted and vertically received) return in green; and the sum of the two channels in blue. The area shown is approximately 37 kilometers by 25 kilometers (23 miles by 16 miles). The radar data, coupled with pre-flood aerial photography and satellite data and post-flood topographic and field data, are being used to evaluate changes associated with levee breaks in landforms, where deposits formed during the widespread flooding in 1993 along the Missouri and Mississippi Rivers. The distinct radar scattering properties of farmland, sand fields and scoured areas will be used to inventory floodplains along the Missouri River and determine the processes by which these areas return to preflood conditions. The image shows one such levee break near Glasgow, Missouri. In the upper center of the radar image is a region covered by several meters of sand, shown as blue regions below the bend in the river. West (left) of this dark area, a blue gap in the levee tree canopy can be seen, showing the area where the levee failed. Radar data such as these can help scientists more accurately assess the potential for future flooding in this region and how that might impact surrounding communities. 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 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.

  11. Apodized RFI filtering of synthetic aperture radar images

    SciTech Connect

    Doerry, Armin Walter

    2014-02-01

    Fine resolution Synthetic Aperture Radar (SAR) systems necessarily require wide bandwidths that often overlap spectrum utilized by other wireless services. These other emitters pose a source of Radio Frequency Interference (RFI) to the SAR echo signals that degrades SAR image quality. Filtering, or excising, the offending spectral contaminants will mitigate the interference, but at a cost of often degrading the SAR image in other ways, notably by raising offensive sidelobe levels. This report proposes borrowing an idea from nonlinear sidelobe apodization techniques to suppress interference without the attendant increase in sidelobe levels. The simple post-processing technique is termed Apodized RFI Filtering (ARF).

  12. 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 indicates areas of canopy burn and mixed burn with a biomass of between 12 to 20 tons per hectare; light green is mixed burn and on-burn forest with a biomass of 20 to 35 tons per hectare; and green is non-burned forest with a biomass of greater than 35 tons per hectare. Forest recovery from the fire seems to depend on fire intensity and soil conditions. In areas of severe canopy burn and poor soil conditions, crown biomass was still low in 1994 (indicated by the brown areas at the center left), whereas in areas of mixed burn with nutrient-rich soils, seen west of Yellowstone Lake, crown biomass has increased significantly in six years (indicated by the yellow and light green areas). Imaging fire-affected regions with spaceborne radar illustrates SIR-C/X-SAR's keen abilities to monitor regrowth after a fire. Knowing the amount of carbon accumulated in the atmosphere by regenerating forest in the 20 to 50 years following a fire disturbance is also a significant factor in understanding the global carbon cycle. Measuring crown biomass is necessary to evaluate the effects of past and future fires in specific regions. Spaceborne Imaging Radar-C and X-Synthetic Aperture Radar (SIR-C/X-SAR) are 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 that are caused by nature and those changes that 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 Italian

  13. Space Radar Image of the Lost City of Ubar

    NASA Technical Reports Server (NTRS)

    1999-01-01

    This is a radar image of the region around the site of the lost city of Ubar in southern Oman, on the Arabian Peninsula. The ancient city was discovered in 1992 with the aid of remote sensing data. Archeologists believe Ubar existed from about 2800 B.C. to about 300 A.D. and was a remote desert outpost where caravans were assembled for the transport of frankincense across the desert. This image was acquired on orbit 65 of space shuttle Endeavour on April 13, 1994 by the Spaceborne Imaging Radar C/X-Band Synthetic Aperture Radar (SIR-C/X-SAR). The SIR-C image shown is centered at 18.4 degrees north latitude and 53.6 degrees east longitude. The image covers an area about 50 by 100 kilometers (31 miles by 62 miles). The image is constructed from three of the available SIR-C channels and displays L-band, HH (horizontal transmit and receive) data as red, C-band HH as blue, and L-band HV (horizontal transmit, vertical receive) as green. The prominent magenta colored area is a region of large sand dunes, which are bright reflectors at both L-and C-band. The prominent green areas (L-HV) are rough limestone rocks, which form a rocky desert floor. A major wadi, or dry stream bed, runs across the middle of the image and is shown largely in white due to strong radar scattering in all channels displayed (L and C HH, L-HV). The actual site of the fortress of the lost city of Ubar, currently under excavation, is near the Wadi close to the center of the image. The fortress is too small to be detected in this image. However, tracks leading to the site, and surrounding tracks, appear as prominent, but diffuse, reddish streaks. These tracks have been used in modern times, but field investigations show many of these tracks were in use in ancient times as well. Mapping of these tracks on regional remote sensing images was a key to recognizing the site as Ubar in 1992. This image, and ongoing field investigations, will help shed light on a little known early civilization. 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.

  14. Imaging radar polarimetry from wave synthesis

    NASA Technical Reports Server (NTRS)

    Zebker, Howard A.; Van Zyl, Jakob J.; Held, Daniel N.

    1987-01-01

    A new approach is reported to the measurement of the complete polarization signature of each resolution element in an image implemented with an airborne synthetic aperture radar system. Signals recorded on one data pass from orthogonal linearly polarized antennas are utilized. The signals are combined in a data processor to synthesize any desired combination of transmit and receive polarizations. The technique permits measurement of the complex, multichannel reflectivity of a scene on a single aircraft pass and to late reprocess the data to provide multiple image maps, with each representing the backscattered energy from the scene measured with a different combination of observational transmit and recieve polarizations. The resulting polarization signature measurements indicate optimum polarizations for observations of certain classes of objects and give insight into the identification of dominant scattering mechanisms for each kind of object. The mathematical model for polarization synthesis is summarized, and some theoretical polarization measurements are illustrated for several types of targets. The overall radar system implementation is described in detail. Some analyses of data acquired on three aircraft flights are presented. The technique has been applied to mapping and differentiation of lava flows and to differentiation of forested and clear-cut areas.

  15. Terahertz inverse synthetic aperture radar (ISAR) imaging with a

    E-print Network

    Massachusetts at Lowell, University of

    ," Opt. Lett. 33, 440-442 (2008). 7. D. L. Mensa, High Resolution Radar Cross-Section Imaging, (ArtechTerahertz inverse synthetic aperture radar (ISAR) imaging with a quantum cascade laser transmitter (TQCL) laser as the transmitter and an optically pumped molecular laser as the local oscillator has been

  16. Space Radar Image of St. Louis, Missouri

    NASA Technical Reports Server (NTRS)

    1994-01-01

    This is a spaceborne radar image of the area surrounding St. Louis, Missouri, where the Mississippi and Missouri Rivers come together. The city of St. Louis is the bright gold area within a bend in the Mississippi River at the lower center of the image. The rivers show up as dark blue sinuous lines. Urbanized areas appear bright gold and forested areas are shown as a brownish color. Several bridges can be seen spanning the river near downtown St. Louis. The Missouri River flows east, from left to right, across the center of the image, and meets the Mississippi River, which flows from top to bottom of the image. A small stretch of the Illinois River is shown at the top of the image where it merges with the Mississippi. The Mississippi forms the state boundary between Illinois (to the right) and Missouri (to the left). Flat farmland areas within the river floodplains appear blue on the image. The major roadways that pass through the area can be seen radiating out from, and encircling, the city of St. Louis. These highways, the rivers and the bridges help maintain St. Louis' reputation as the 'Gateway to the West.

  17. Convolution backprojection image reconstruction for spotlight mode synthetic aperture radar.

    PubMed

    Desai, M D; Jenkins, W K

    1992-01-01

    Convolution backprojection (CBP) image reconstruction has been proposed as a means of producing high-resolution synthetic-aperture radar (SAR) images by processing data directly in the polar recording format which is the conventional recording format for spotlight mode SAR. The CBP algorithm filters each projection as it is recorded and then backprojects the ensemble of filtered projections to create the final image in a pixel-by-pixel format. CBP reconstruction produces high-quality images by handling the recorded data directly in polar format. The CBP algorithm requires only 1-D interpolation along the filtered projections to determine the precise values that must be contributed to the backprojection summation from each projection. The algorithm is thus able to produce higher quality images by eliminating the inaccuracies of 2-D interpolation, as well as using all the data recorded in the spectral domain annular sector more effectively. The computational complexity of the CBP algorithm is O(N (3)). PMID:18296183

  18. 2ND INTERNATIONAL WORKSHOP ON ADVANCED GROUND PENETRATING RADAR (IWAGPR), DELFT, THE NETHERLANDS, MAY 2003 1 Processing of polarimetric infrared images for

    E-print Network

    van Vliet, Lucas J.

    , MAY 2003 1 Processing of polarimetric infrared images for landmine detection Frank Cremer, Wim de Jong is to show the processing algorithms for images measured with a polarimetric infrared camera. In images infrared camera as discussed in Sec. II. The second step, the pre-processing, converts the raw images from

  19. Space Radar Image of Central African Gorilla Habitat

    NASA Technical Reports Server (NTRS)

    1999-01-01

    This is a false-color radar image of Central Africa, showing the Virunga Volcano chain along the borders of Rwanda, Zaire and Uganda. This area is home to the endangered mountain gorillas. This C-band L-band image was acquired on April 12, 1994, on orbit 58 of space shuttle Endeavour by the Spaceborne Imaging Radar-C/X-band Synthetic Aperture Radar (SIR-C/X-SAR). The area is centered at about 1.75 degrees south latitude and 29.5 degrees east longitude. The image covers an area 58 kilometers by 178 kilometers (48 miles by 178 miles). The false-color composite is created by displaying the L-band HH return in red, the L-band HV return in green and the C-band HH return in blue. The dark area in the bottom of the image is Lake Kivu, which forms the border between Zaire (to the left) and Rwanda (to the right). The airport at Goma, Zaire is shown as a dark line just above the lake in the bottom left corner of the image. Volcanic flows from the 1977 eruption of Mt. Nyiragongo are shown just north of the airport. Mt. Nyiragongo is not visible in this image because it is located just to the left of the image swath. Very fluid lava flows from the 1977 eruption killed 70 people. Mt. Nyiragongo is currently erupting (August 1994) and will be a target of observation during the second flight of SIR-C/X-SAR. The large volcano in the center of the image is Mt. Karisimbi (4,500 meters or 14,800 feet). This radar image highlights subtle differences in the vegetation and volcanic flows of the region. The faint lines shown in the purple regions are believed to be the result of agriculture terracing by the people who live in the region. The vegetation types are an important factor in the habitat of the endangered mountain gorillas. Researchers at Rutgers University in New Jersey and the Dian Fossey Gorilla Fund in London will use this data to produce vegetation maps of the area to aid in their study of the remaining 650 gorillas in the region. 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.

  20. A Butterfly Algorithm for Synthetic Aperture Radar Imaging

    E-print Network

    Demanet, Laurent

    In spite of an extensive literature on fast algorithms for synthetic aperture radar (SAR) imaging, it is not currently known if it is possible to accurately form an image from N data points in provable near-linear time ...

  1. Space Radar Image of Raco, Michigan

    NASA Technical Reports Server (NTRS)

    1999-01-01

    This image is a false-color composite of Raco, Michigan, centered at 46.39 degrees north latitude, 84.88 degrees west longitude. 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 sixth orbit and during the first full-capability test of the instrument on April 9, 1994. This image was produced using both L-band and C-band data. The area shown is approximately 20 kilometers by 50 kilometers (12 by 30 miles). Raco is located at the eastern end of Michigan's upper peninsula, west of Sault Ste. Marie and south of Whitefish Bay on Lake Superior. The site is located at the boundary between the boreal forests and the northern temperate forests, a transitional zone that is expected to be ecologically sensitive to anticipated global changes resulting from climatic warming. On any given day, there is a 60 percent chance that this area will be obscured to some extent by cloud clover which makes it difficult to image using optical sensors. In this color representation (red=LHH,green=LHV, blue=CHH), darker areas in the image are smooth surfaces such as frozen lakes and other non-forested areas. The colors are related to the types of trees and the brightness is related to the amount of plant material covering the surface, called forest biomass. The black area in the upper right corner is the ice-covered Lake Superior. The blue mosaic areas in the lower part of the image are bare agricultural fields with hay stubble. The large blue area to the center left of the image corresponds to a large frozen swamp with no trees and lots of grass tufts. The light greenish-yellow areas are red pine trees approximately 30 meters (100 feet) in height. The brownish yellow areas are jack pine trees of various ages. The dark patches are areas of recent clear cuts in the managed Hiawatha National Forest. The shore line of Lake Superior in the light greenish blue is a mixture of aspen and birch trees. South of that, surrounding McNearny and Johnson lakes is a dark purple area containing north hardwoods. Accurate information about land-cover is important to area resource managers and for use in regional-to-global-scale scientific models used understand global change.

  2. 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 Venusian latitudes. Examples of anomalies and system artifacts that can affect image interpretation are described.

  3. Engineering studies related to the Skylab program. Task H: Microwave/optical/infrared image processing for ocean current recognition. [from radar altimeter data

    NASA Technical Reports Server (NTRS)

    Smith, A. G.

    1974-01-01

    Images from the Skylab S-193 radar altimeter were selected from data obtained on appropriate passes made by Skylabs 2, 3, and 4 missions for the following three objectives: (1) to serve as a precursor to an investigation for the planned GEOS-C mission, in which radar altimeter data will be analyzed to reveal ocean current related to surface topography; (2) to determine the value of satellite infrared and visual radiometer data as potential sources of ground truth data, the results of which be incorporated in the planning of the SEASAT program; and (3) to determine whether optimal data reduction techniques are useful for revealing clues on Gulf Stream topographic signature characteristics. The results obtained which apply to the stated objectives are discussed.

  4. Space Radar Image of the Yucatan Impact Crater Site

    NASA Technical Reports Server (NTRS)

    1999-01-01

    This is a radar image of the southwest portion of the buried Chicxulub impact crater in the Yucatan Peninsula, Mexico. The radar image was acquired on orbit 81 of space shuttle Endeavour on April 14, 1994 by the Spaceborne Imaging Radar C/X-Band Synthetic Aperture Radar (SIR-C/X-SAR). The image is centered at 20 degrees north latitude and 90 degrees west longitude. Scientists believe the crater was formed by an asteroid or comet which slammed into the Earth more than 65 million years ago. It is this impact crater that has been linked to a major biological catastrophe where more than 50 percent of the Earth's species, including the dinosaurs, became extinct. The 180-to 300-kilometer-diameter (110- to 180-mile)crater is buried by 300 to 1,000 meters (1,000 to 3,000 feet) of limestone. The exact size of the crater is currently being debated by scientists. This is a total power radar image with L-band in red, C-band in green, and the difference between C-band L-band in blue. The 10-kilometer-wide (6-mile) band of yellow and pink with blue patches along the top left (northwestern side) of the image is a mangrove swamp. The blue patches are islands of tropical forests created by freshwater springs that emerge through fractures in the limestone bedrock and are most abundant in the vicinity of the buried crater rim. The fracture patterns and wetland hydrology in this region are controlled by the structure of the buried crater. Scientists are using the SIR-C/X-SAR imagery to study wetland ecology and help determine the exact size of the impact crater. 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. Research on the biological effects of the Chicxulub impact is supported by the NASA Exobiology Program.

  5. Terrain Classification in Central Navarre (Spain) Using Polarimetric Radar Images

    NASA Astrophysics Data System (ADS)

    Larrañaga, A.; Álvarez-Mozos, J.; Albizua, L.; Barinagarrementeria, I.

    2009-04-01

    Traditionally in Navarre, studies concerning remote sensing techniques have been carried out using optical sensor data. However, cloud cover frequently hampers the acquisition of optical data, causing limitations in its use. Radar sensors are not affected by clouds and, apart from that, the new generation of space-borne radar sensors available offer new capabilities such as the ability to operate with multiple polarizations simultaneously, acquiring polarimetric observations. The main objective of this study is to evaluate the feasibility of polarimetric radar observations for terrain classification in central Navarre. The use of radar images in Navarre is something new because until now these images only have been used to do doctoral thesis.

  6. Clutter discrimination algorithm simulation in pulse laser radar imaging

    NASA Astrophysics Data System (ADS)

    Zhang, Yan-mei; Li, Huan; Guo, Hai-chao; Su, Xuan; Zhu, Fule

    2015-10-01

    Pulse laser radar imaging performance is greatly influenced by different kinds of clutter. Various algorithms are developed to mitigate clutter. However, estimating performance of a new algorithm is difficult. Here, a simulation model for estimating clutter discrimination algorithms is presented. This model consists of laser pulse emission, clutter jamming, laser pulse reception and target image producing. Additionally, a hardware platform is set up gathering clutter data reflected by ground and trees. The data logging is as clutter jamming input in the simulation model. The hardware platform includes a laser diode, a laser detector and a high sample rate data logging circuit. The laser diode transmits short laser pulses (40ns FWHM) at 12.5 kilohertz pulse rate and at 905nm wavelength. An analog-to-digital converter chip integrated in the sample circuit works at 250 mega samples per second. The simulation model and the hardware platform contribute to a clutter discrimination algorithm simulation system. Using this system, after analyzing clutter data logging, a new compound pulse detection algorithm is developed. This new algorithm combines matched filter algorithm and constant fraction discrimination (CFD) algorithm. Firstly, laser echo pulse signal is processed by matched filter algorithm. After the first step, CFD algorithm comes next. Finally, clutter jamming from ground and trees is discriminated and target image is produced. Laser radar images are simulated using CFD algorithm, matched filter algorithm and the new algorithm respectively. Simulation result demonstrates that the new algorithm achieves the best target imaging effect of mitigating clutter reflected by ground and trees.

  7. Synthetic aperture radar signal processing on the MPP

    NASA Technical Reports Server (NTRS)

    Ramapriyan, H. K.; Seiler, E. J.

    1987-01-01

    Satellite-borne Synthetic Aperture Radars (SAR) sense areas of several thousand square kilometers in seconds and transmit phase history signal data several tens of megabits per second. The Shuttle Imaging Radar-B (SIR-B) has a variable swath of 20 to 50 km and acquired data over 100 kms along track in about 13 seconds. With the simplification of separability of the reference function, the processing still requires considerable resources; high speed I/O, large memory and fast computation. Processing systems with regular hardware take hours to process one Seasat image and about one hour for a SIR-B image. Bringing this processing time closer to acquisition times requires an end-to-end system solution. For the purpose of demonstration, software was implemented on the present Massively Parallel Processor (MPP) configuration for processing Seasat and SIR-B data. The software takes advantage of the high processing speed offered by the MPP, the large Staging Buffer, and the high speed I/O between the MPP array unit and the Staging Buffer. It was found that with unoptimized Parallel Pascal code, the processing time on the MPP for a 4096 x 4096 sample subset of signal data ranges between 18 and 30.2 seconds depending on options.

  8. DIGITAL VISION he advent of phased array radars and space-time adaptive processing has given radar

    E-print Network

    Nehorai, Arye

    © DIGITAL VISION T he advent of phased array radars and space-time adaptive processing has given radar designers the ability make radars adaptable on receive. The current state of radar technolo- gy of pairs of complementary sequences. Shortly thereafter, Welti proposed to use Golay sequences in radar

  9. Ultrawideband radar imaging system for biomedical applications

    SciTech Connect

    Jafari, H.M.; Liu, W.; Hranilovic, S.; Deen, M.J.

    2006-05-15

    Ultrawideband (UWB) (3-10 GHz) radar imaging systems offer much promise for biomedical applications such as cancer detection because of their good penetration and resolution characteristics. The underlying principle of UWB cancer detection is a significant contrast in dielectric properties, which is estimated to be greater than 2:1 between normal and cancerous tissue, compared to a few-percent contrast in radiographic density exploited by x rays. This article presents a feasibility study of the UWB imaging of liver cancer tumors, based on the frequency-dependent finite difference time domain method. The reflection, radiation, and scattering properties of UWB pulses as they propagate through the human body are studied. The reflected and back-scattered electromagnetic energies from cancer tumors inside the liver are also investigated. An optimized, ultrawideband antenna was designed for near field operation, allowing for the reduction of the air-skin interface. It will be placed on the fat-liver tissue phantom with a malignant tumor stimulant. By performing an incremental scan over the phantom and removing early time artifacts, including reflection from the antenna ends, images based on the back-scattered signal from the tumor can be constructed. This research is part of our effort to develop a UWB cancer detection system with good detection and localization properties.

  10. Image Processing

    NASA Technical Reports Server (NTRS)

    1993-01-01

    Electronic Imagery, Inc.'s ImageScale Plus software, developed through a Small Business Innovation Research (SBIR) contract with Kennedy Space Flight Center for use on space shuttle Orbiter in 1991, enables astronauts to conduct image processing, prepare electronic still camera images in orbit, display them and downlink images to ground based scientists for evaluation. Electronic Imagery, Inc.'s ImageCount, a spin-off product of ImageScale Plus, is used to count trees in Florida orange groves. Other applications include x-ray and MRI imagery, textile designs and special effects for movies. As of 1/28/98, company could not be located, therefore contact/product information is no longer valid.

  11. Statement of capabilities: Micropower Impulse Radar (MIR) technology applied to mine detection and imaging

    SciTech Connect

    Azevedo, S.G.; Gavel, D.T.; Mast, J.E.; Warhus, J.P.

    1995-03-13

    The Lawrence Livermore National Laboratory (LLNL) has developed radar and imaging technologies with potential applications in mine detection by the armed forces and other agencies involved in demining efforts. These new technologies use a patented ultra-wideband (impulse) radar technology that is compact, low-cost, and low power. Designated as Micropower Impulse Radar, these compact, self-contained radars can easily be assembled into arrays to form complete ground penetrating radar imaging systems. LLNL has also developed tomographic reconstruction and signal processing software capable of producing high-resolution 2-D and 3-D images of objects buried in materials like soil or concrete from radar data. Preliminary test results have shown that a radar imaging system using these technologies has the ability to image both metallic and plastic land mine surrogate targets buried in 5 to 10 cm of moist soil. In dry soil, the system can detect buried objects to a depth of 30 cm and more. This report describes LLNL`s unique capabilities and technologies that can be applied to the demining problem.

  12. Real-time implementation of frequency-modulated continuous-wave synthetic aperture radar imaging using field programmable gate array

    NASA Astrophysics Data System (ADS)

    Quan, Yinghui; Li, Yachao; Hu, Guibin; Xing, Mengdao

    2015-06-01

    A new miniature linear frequency-modulated continuous-wave radar which mounted on an unmanned aerial vehicle is presented. It allows the accomplishment of high resolution synthetic aperture radar imaging in real-time. Only a Kintex-7 field programmable gate array from Xilinx is utilized for whole signal processing of sophisticated radar imaging algorithms. The proposed hardware architecture achieves remarkable improvement in integration, power consumption, volume, and computing performance over its predecessor designs. The realized design is verified by flight campaigns.

  13. 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.

  14. Censoring Biological Echoes in Weather Radar Images Valliappa Lakshmanan

    E-print Network

    Lakshmanan, Valliappa

    , biological contaminants can not be easily removed by means of such local texture or vertical profile featuresCensoring Biological Echoes in Weather Radar Images Valliappa Lakshmanan University of Oklahoma/Office of Atmospheric Research Norman, Oklahoma, USA Abstract Weather radar data is susceptible to several artifacts due

  15. Radar Images of the Earth and the World Wide Web

    NASA Technical Reports Server (NTRS)

    Chapman, B.; Freeman, A.

    1995-01-01

    A perspective of NASA's Jet Propulsion Laboratory as a center of planetary exploration, and its involvement in studying the earth from space is given. Remote sensing, radar maps, land topography, snow cover properties, vegetation type, biomass content, moisture levels, and ocean data are items discussed related to earth orbiting satellite imaging radar. World Wide Web viewing of this content is discussed.

  16. Proceedings of the Third Spaceborne Imaging Radar Symposium

    NASA Technical Reports Server (NTRS)

    1993-01-01

    This publication contains summaries of the papers presented at the Third Spaceborne Imaging Radar Symposium held at the Jet Propulsion Laboratory (JPL), California Institute of Technology, in Pasadena, California, on 18-21 Jan. 1993. The purpose of the symposium was to present an overview of recent developments in the different scientific and technological fields related to spaceborne imaging radars and to present future international plans. This symposium is the third in a series of 'Spaceborne Imaging Radar' symposia held at JPL. The first symposium was held in Jan. 1983 and the second in 1986.

  17. Varying FM Rates in Adaptive Processing for Distributed Radar Apertures

    E-print Network

    Adve, Raviraj

    to the application of target detection for a distributed radar aperture system in the presence of noise and clutter detection for a distributed radar aperture system in the presence of noise and clutter. CruciallyVarying FM Rates in Adaptive Processing for Distributed Radar Apertures Earnest Lock and Raviraj S

  18. Maximum Likelihood Methods in Radar Array Signal Processing

    E-print Network

    Swindlehurst, A. Lee

    invariance principle, likelihood ratio detection test, maximum likelihood estimation, radar cross section radar cross section), direction of arrival (DOA), range, and Doppler frequency. Even when only a singleMaximum Likelihood Methods in Radar Array Signal Processing A. LEE SWINDLEHURST, MEMBER, IEEE

  19. IFP V4.0:a polar-reformatting image formation processor for synthetic aperture radar.

    SciTech Connect

    Eichel, Paul H.

    2005-09-01

    IFP V4.0 is the fourth generation of an extraordinarily powerful and flexible image formation processor for spotlight mode synthetic aperture radar. It has been successfully utilized in processing phase histories from numerous radars and has been instrumental in the development of many new capabilities for spotlight mode SAR. This document provides a brief history of the development of IFP, a full exposition of the signal processing steps involved, and a short user's manual for the software implementing this latest iteration.

  20. A radar data processing and enhancement system

    NASA Technical Reports Server (NTRS)

    Anderson, K. F.; Wrin, J. W.; James, R.

    1986-01-01

    This report describes the space position data processing system of the NASA Western Aeronautical Test Range. The system is installed at the Dryden Flight Research Facility of NASA Ames Research Center. This operational radar data system (RADATS) provides simultaneous data processing for multiple data inputs and tracking and antenna pointing outputs while performing real-time monitoring, control, and data enhancement functions. Experience in support of the space shuttle and aeronautical flight research missions is described, as well as the automated calibration and configuration functions of the system.

  1. Radar beam- and range-weighting effects on three-dimensional radar imaging for the atmosphere

    NASA Astrophysics Data System (ADS)

    Chen, Jenn-Shyong; Chen, Chun-Hua; Furumoto, Jun-Ichi

    2011-12-01

    Multiple-receiver and multiple-frequency radar imaging techniques used with VHF atmospheric radar can improve, respectively, angular and range resolutions of the atmospheric irregularity structure inside the radar volume. In addition to the imaging method itself, calibration of the imaging is also crucial to yield a better visualization of the irregularity structure. In this paper, the three-dimensional radar imaging using multiple receivers and multiple frequencies simultaneously is demonstrated on the basis of numerical simulation with the Capon method. More than previous works did, radar beam and range weighting effects on the imaging were examined in this study. Beam weighting effect on angular brightness distribution of the scattering region is apparent, but it gives different impacts on the range imaging as accompanying with the range weighting effect: the higher the range position of the scattering region is, the smaller the synthetic influence of both weighting effects will be. Beam weighting effect also causes a range-shortening effect for a localized scattering region, which should be considered in interpreting the shift of range brightness distribution with angular location of the target. Moreover, it is demonstrated that adaptable beam width is effectual to recover a two-blob structure and a wavy layer. An experimental case was also investigated to demonstrate the need of correcting beam weighting effect using adaptable beam width; meanwhile, it suggests that an adaptable range weighting function could be helpful to a further amendment of the three-dimensional imaging.

  2. Three-dimensional radar imaging of buildings based on computer models

    NASA Astrophysics Data System (ADS)

    Dogaru, Traian; Liao, DaHan; Le, Calvin

    2013-05-01

    This paper describes the study of a through-the-wall radar system for three-dimensional (3-D) building imaging, based on computer simulations. Two possible configurations are considered, corresponding to an airborne spotlight and a ground-based strip-map geometry. The paper details all the steps involved in this analysis: creating the computational meshes, calculating the radar signals scattered by the target, forming the radar images, and processing the images for visualization and interpretation. Particular attention is given to the scattering phenomenology and its dependence on the system geometry. The images are created via the backprojection algorithm and further processed using a constant falsealarm rate (CFAR) detector. We discuss methods of 3-D image visualization and interpretation of the results.

  3. Computational Burden Resulting from Image Recognition of High Resolution Radar Sensors

    PubMed Central

    López-Rodríguez, Patricia; Fernández-Recio, Raúl; Bravo, Ignacio; Gardel, Alfredo; Lázaro, José L.; Rufo, Elena

    2013-01-01

    This paper presents a methodology for high resolution radar image generation and automatic target recognition emphasizing the computational cost involved in the process. In order to obtain focused inverse synthetic aperture radar (ISAR) images certain signal processing algorithms must be applied to the information sensed by the radar. From actual data collected by radar the stages and algorithms needed to obtain ISAR images are revised, including high resolution range profile generation, motion compensation and ISAR formation. Target recognition is achieved by comparing the generated set of actual ISAR images with a database of ISAR images generated by electromagnetic software. High resolution radar image generation and target recognition processes are burdensome and time consuming, so to determine the most suitable implementation platform the analysis of the computational complexity is of great interest. To this end and since target identification must be completed in real time, computational burden of both processes the generation and comparison with a database is explained separately. Conclusions are drawn about implementation platforms and calculation efficiency in order to reduce time consumption in a possible future implementation. PMID:23609804

  4. Space Radar Image of Raco, Michigan, ecological test site

    NASA Technical Reports Server (NTRS)

    1994-01-01

    This is an X-band image of seasonal changes at the ecological test site of Raco, Michigan, located south of Whitefish Bay on Lake Superior. The image is centered at about 46 degrees north latitude and 85 degrees west longitude. This image was acquired by the X-band Synthetic Aperture Radar onboard the space shuttle Endeavour on April 10th, 1994, and on October 1, 1994. The areas shown in red correspond to the April 10th data; the areas in blue correspond to data acquired on October 1, 1994; green indicates the ratio of data acquired on April 10 and October 1, 1994. The area shown is 22.7 kilometers by 53 kilometers (14 miles by 33 miles). Lake Superior in the upper right was frozen in April and had small waves (ripples) on its surface in October. The land area contains mostly forests and, to a lesser extent, agricultural regions. In April the area was covered in wet snow. By October, there agricultural areas were covered with grass. Vegetation and soils were moist due to rainfalls three days before the data was acquired on October 1, 1994. The bright light green/yellow tones in the lower half of the image show the stronger reflections of the snow-covered agricultural fields. The pinkish color corresponds to the coniferous and deciduous forests. The green area represents red pines. These trees are smaller than the surrounding forest cover and allow more radar penetration. The area is green because the radar is sensing the surface, which undergoes great change from snow to grass and fern undergrowth between April and October. The bright green triangle in the upper half of the image is an old airstrip, while the modern airport can be seen on the bottom right side of the image. The Raco site is an important location for monitoring seasonal changes and future global change because it is situated at the ecological transition zone between the boreal forests and the northern temperate forests. This transitional zone is expected to be ecologically sensitive to anticipated global changes resulting from climatic warming. Baseline studies of vegetation are essential in monitoring these expected changes. 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 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.

  5. Shuttle Imaging Radar-C (SIR-C): Executive summary

    NASA Technical Reports Server (NTRS)

    1983-01-01

    The scientific and technological objectives of the Shuttle Imaging Radar-C (SIR-C) Project are reviewed. Information regarding the implementation philosophy and approach, and the relationship of the project to the overall SIR program is also provided.

  6. Imaging radar investigations of the Sudbury structure

    NASA Technical Reports Server (NTRS)

    Lowman, P. D.; Singhroy, V. H.; Slaney, V. R.

    1992-01-01

    This paper reports preliminary results of airborne imaging radar studies of the Sudbury structure carried out in preparation for a CCRS European Remote Sensing Satellite (ERS-1) investigation. The data used were synthetic aperture radar (SAR) C-band (5.66 cm) images acquired from about 6 km altitude in 1987. They cover the Sudbury area in both wide and narrow swath modes, with east-west flight paths and north-south illumination directions. Narrow swath resolution is 6 m in range and azimuth; wide swath resolution is 20 m in range and 10 m in azimuth. The STAR imagery has proven highly effective for field use, providing excellent rendition of topography and topographically expressed structure. Reasons for this include the illumination geometry, notably the look azimuth normal to the long axis of the Sudbury structure and Penokean fold axes, the good spatial resolution, and the short wavelength. Forested areas in the Sudbury area tend to be uniformly rough at C-band wavelength, with backscatter dominated by local incidence angle (i.e., topography). Field work using the SAR imagery has to date been concentrated in the North Range and Superior Province as far north as the Benny greenstone belt. This area was chosen for initial investigation of the original size and shape of the Sudbury structure because the effects of the Penokean Orogeny were minimal there. Field work using SAR indicates that there has been little postimpact deformation of the North Range or adjacent Superior Province rock. There appears to be no evidence for an outer ring concentric with the North Range as indicated by early Landsat imagery. The apparent ring shown by Landsat is visible on the SAR imagery as the intersection of two regional fracture patterns not related to the Sudbury structure. There is no outer ring visible southwest of the structure. This can reasonably be explained by Penokean deformation, but there is no outer ring to the northeast cutting the relatively undeformed Huronian sediments of the Cobalt Embayment.

  7. Beam Width Robustness of a 670 GHz Imaging Radar

    NASA Technical Reports Server (NTRS)

    Cooper, K. B.; Llombart, N.; Dengler, R. J.; Siegel, P. H.

    2009-01-01

    Detection of a replica bomb belt concealed on a mannequin at 4 m standoff range is achieved using a 670 GHz imaging radar. At a somewhat larger standoff range of 4.6 m, the radar's beam width increases substantially, but the through-shirt image quality remains good. This suggests that a relatively modest increase in aperture size over the current design will be sufficient to detect person-borne concealed weapons at ranges exceeding 25 meters.

  8. Signal processing for airborne bistatic radar 

    E-print Network

    Ong, Kian P

    The major problem encountered by an airborne bistatic radar is the suppression of bistatic clutter. Unlike clutter echoes for a sidelooking airborne monostatic radar, bistatic clutter echoes are range dependent. Using ...

  9. Goldstone solar system radar signal processing

    NASA Technical Reports Server (NTRS)

    Jurgens, R.; Satorius, E.; Sanchez, O.

    1992-01-01

    A performance analysis of the planetary radar data acquisition system is presented. These results extend previous computer simulation analysis and are facilitated by the development of a simple analytical model that predicts radar system performance over a wide range of operational parameters. The results of this study are useful to both the radar system designer and the science investigator in establishing operational radar data acquisition parameters which result in the best systems performance for a given set of input conditions.

  10. Goldstone solar system radar signal processing

    NASA Technical Reports Server (NTRS)

    Jurgens, R. F.; Satorius, E.; Sanchez, O.

    1992-01-01

    A performance analysis of the planetary radar data acquisition system is presented. These results extend previous computer simulation analysis and are facilitated by the development of a simple analytical model that predicts radar system performance over a wide range of operational parameters. The results of this study are useful to both the radar systems designer and the science investigator in establishing operational radar data acquisition parameters which result in the best systems performance for a given set of input conditions.

  11. Edge detection for synthetic aperture radar and other noisy images

    NASA Technical Reports Server (NTRS)

    Frost, V. S.; Shanmugan, K. S.; Holtzman, J. C.

    1982-01-01

    The development is examined of a new edge detector which is shown to perform adequately in the non-Gaussian multiplicative noise environment which characterizes radar images. This edge detector operates over larger local neighborhood and is less susceptible to noise than previous edge detectors and is therefore more suitable for radar. In addition, a radar image noise model is employed for the design of this new operator. This edge detector is unique in that it is assumed that every local area belongs to either the class of local areas not containing edges or to the class of local areas containing edges. Each pixel's local neighborhood is then assigned to one of these two classes using a statistical hypothesis (a likelihood ratio) test. It is demonstrated that this algorithm is useful for detecting edges in radar images.

  12. SIMULATION OF ORBITAL RADAR IMAGES R. S. Saunders

    E-print Network

    Faraon, Andrei

    synthetic aperture imaging radar system. The land images contain a wide variety of geologic features (Figure 1) and preliminary analyses indicate that the Seasat images may be a useful geologic mapping tool\\NGLE a b TIME 1 a a c GROUND RANGE PROJECTION a Figure 2. Illustration of layover and shadow

  13. Multispectral microwave imaging radar for remote sensing applications

    NASA Technical Reports Server (NTRS)

    Larson, R. W.; Rawson, R.; Ausherman, D.; Bryan, L.; Porcello, L.

    1974-01-01

    A multispectral airborne microwave radar imaging system, capable of obtaining four images simultaneously is described. The system has been successfully demonstrated in several experiments and one example of results obtained, fresh water ice, is given. Consideration of the digitization of the imagery is given and an image digitizing system described briefly. Preliminary results of digitization experiments are included.

  14. The APL image processing laboratory

    NASA Technical Reports Server (NTRS)

    Jenkins, J. O.; Randolph, J. P.; Tilley, D. G.; Waters, C. A.

    1984-01-01

    The present and proposed capabilities of the Central Image Processing Laboratory, which provides a powerful resource for the advancement of programs in missile technology, space science, oceanography, and biomedical image analysis, are discussed. The use of image digitizing, digital image processing, and digital image output permits a variety of functional capabilities, including: enhancement, pseudocolor, convolution, computer output microfilm, presentation graphics, animations, transforms, geometric corrections, and feature extractions. The hardware and software of the Image Processing Laboratory, consisting of digitizing and processing equipment, software packages, and display equipment, is described. Attention is given to applications for imaging systems, map geometric correction, raster movie display of Seasat ocean data, Seasat and Skylab scenes of Nantucket Island, Space Shuttle imaging radar, differential radiography, and a computerized tomographic scan of the brain.

  15. Onboard Data Processor for Change-Detection Radar Imaging

    NASA Technical Reports Server (NTRS)

    Lou, Yunling; Muellerschoen, Ronald J.; Chien, Steve A.; Saatchi, Sasan S.; Clark, Duane

    2008-01-01

    A computer system denoted a change-detection onboard processor (CDOP) is being developed as a means of processing the digitized output of a synthetic-aperture radar (SAR) apparatus aboard an aircraft or spacecraft to generate images showing changes that have occurred in the terrain below between repeat passes of the aircraft or spacecraft over the terrain. When fully developed, the CDOP is intended to be capable of generating SAR images and/or SAR differential interferograms in nearly real time. The CDOP is expected to be especially useful for understanding some large-scale natural phenomena and/or mitigating natural hazards: For example, it could be used for near-real-time observation of surface changes caused by floods, landslides, forest fires, volcanic eruptions, earthquakes, glaciers, and sea ice movements. It could also be used to observe such longer-term surface changes as those associated with growth of vegetation (relevant to estimation of wildfire fuel loads). The CDOP is, essentially, an interferometric SAR processor designed to operate aboard a radar platform.

  16. A wavefront reconstruction method for 3-D cylindrical subsurface radar imaging.

    PubMed

    Flores-Tapia, Daniel; Thomas, Gabriel; Pistorius, Stephen

    2008-10-01

    In recent years, the use of radar technology has been proposed in a wide range of subsurface imaging applications. Traditionally, linear scan trajectories are used to acquire data in most subsurface radar applications. However, novel applications, such as breast microwave imaging and wood inspection, require the use of nonlinear scan trajectories in order to adjust to the geometry of the scanned area. This paper proposes a novel reconstruction algorithm for subsurface radar data acquired along cylindrical scan trajectories. The spectrum of the collected data is processed in order to locate the spatial origin of the target reflections and remove the spreading of the target reflections which results from the different signal travel times along the scan trajectory. The proposed algorithm was successfully tested using experimental data collected from phantoms that mimic high contrast subsurface radar scenarios, yielding promising results. Practical considerations such as spatial resolution and sampling constraints are discussed and illustrated as well. PMID:18784038

  17. Spaceborne imaging radar research in the 90's

    NASA Technical Reports Server (NTRS)

    Elachi, Charles

    1986-01-01

    The imaging radar experiments on SEASAT and on the space shuttle (SIR-A and SIR-B) have led to a wide interest in the use of spaceborne imaging radars in Earth and planetary sciences. The radar sensors provide unique and complimentary information to what is acquired with visible and infrared imagers. This includes subsurface imaging in arid regions, all weather observation of ocean surface dynamic phenomena, structural mapping, soil moisture mapping, stereo imaging and resulting topographic mapping. However, experiments up to now have exploited only a very limited range of the generic capability of radar sensors. With planned sensor developments in the late 80's and early 90's, a quantum jump will be made in our ability to fully exploit the potential of these sensors. These developments include: multiparameter research sensors such as SIR-C and X-SAR, long-term and global monitoring sensors such as ERS-1, JERS-1, EOS, Radarsat, GLORI and the spaceborne sounder, planetary mapping sensors such as the Magellan and Cassini/Titan mappers, topographic three-dimensional imagers such as the scanning radar altimeter and three-dimensional rain mapping. These sensors and their associated research are briefly described.

  18. Imaging Earthquake From Offsets Measured on Optical or Radar Images

    NASA Astrophysics Data System (ADS)

    Michel, R.; Avouac, J.

    2001-12-01

    The measurement of ground deformation and surface ruptures is a major issue in seismotectonics to address key issue such as fault geometry at depth or rupture dynamics. Satellite or airborne imagery might be used in complement geodetic techniques, which are limited in terms of spatial coverage and which require available preseismic measurements. The approach is based on the simple idea that the horizontal component of the ground deformation that might have occurred in the time span between two image acquisitions induces geometric distortions (offsets) that might be retrieved from the cross-correlation of the two images. Based on the few case examples of co-seismic deformation analyzed at the moment (Landers, 1992; Hector Mine, 1998; Izmit, 1999; Chichi, 1999; Bujh, 2000) we may outline potentialities and limitations of this approach. Both radar and optical images might be used. The characteristic speckle pattern of radar images makes correlation techniques particularly adapted. For optical images we use another technique assuming that deformation is approximated by a local translation, equivalent to a phase shift in the Fourier domain. With ERS radar images the technique provides independent measurements every about 80X320 m2. The azimuthal component of displacement (equivalent, although less accurate, to the unwrapped interferogram) with an accuracy of 35 cm, and the range component with an accuracy of 25 cm. Limitation is due to the availability of SAR images and to the insufficient image resolution. With SPOT images it yields independent measurements every about 80m with an accuracy better than 1/10th of the pixel size (10m). The technique is generally well adapted to delineate zones of high strain, in particular surface ruptures, and estimate of co-seismic slip that can usually not be derived from other techniques (InSar or GPS). The technique suffers limitations in the low frequency domain due to the uncertainty of the changing attitude of the platform during image acquisition. The study of the Chichi test case shows however that this limitation can be overcome by merging offsets with available co-seismic GPS data. The resulting displacement map is an unprecedented data set allowing a comprehensive analysis of the deformation including estimate of both the near fault complexity and the slip gradient at depth. This limitation does not exist for standard photographic technique provided that geometric distortions have not been introduced by digitization. Metric resolution imagery can reveal the detail surface ruptures but is more sensitive to temporal and geometrical decorrelation. The technique is promising because it offers the possibility if measuring ground deformation due to past earthquakes for which air photos are available, and also to the increasing availability of high-resolution satellite imagery. A near real time production of deformation maps might be envisioned in the futures.

  19. 29. Perimeter acquisition radar building room #318, data processing system ...

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

    29. Perimeter acquisition radar building room #318, data processing system area; data processor maintenance and operations center, showing data processing consoles - 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. 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.

  1. Segmentation and cooperative fusion of laser radar image data

    SciTech Connect

    Beckerman, M.; Sweeney, F.J.

    1994-06-01

    In segmentation, the goal is to partition a given 2D image into regions corresponding to the meaningful surfaces in the underlying physical scene. Segmentation is frequently a crucial step in analyzing and interpreting image data acquired by a variety of automated systems ranging from indoor robots to orbital satellites. In this paper, we present results of a study of segmentation by means of cooperative fusion of registered range and intensity images acquired using a prototype amplitude-modulated CW laser radar. In our approach, we consider three modalities -- depth, reflectance and surface orientation. These modalities are modeled as sets of coupled Markov random fields for pixel and line processes. Bayesian inferencing is used to impose constraints of smoothness on the pixel process and linearity on the line process. The latter constraint is modeled using an Ising Hamiltonian. We solve the constrained optimization problem using a form of simulated annealing termed quenched annealing. The resulting model is illustrated in this paper in the rapid quenched, or iterated conditional mode, limit for several laboratory scenes.

  2. Space Radar Image of Giza Egypt - with enlargement

    NASA Technical Reports Server (NTRS)

    1994-01-01

    This radar image shows the area west of the Nile River near Cairo, Egypt. The Nile River is the dark band along the right side of the image and it flows approximately due North from the bottom to the right. The boundary between dense urbanization and the desert can be clearly seen between the bright and dark areas in the center of the image. This boundary represents the approximate extent of yearly Nile flooding which played an important part in determining where people lived in ancient Egypt. This land usage pattern persists to this day. The pyramids at Giza appear as three bright triangles aligned with the image top just at the boundary of the urbanized area. They are also shown enlarged in the inset box in the top left of the image. The Great Pyramid of Khufu (Cheops in Greek) is the northern most of the three Giza pyramids. The side-looking radar illuminates the scene from the top, the two sides of the pyramids facing the radar reflect most of the energy back to the antenna and appear radar bright; the two sides away from the radar reflect less energy back and appear dark Two additional pyramids can be seen left of center in the lower portion of the image. The modern development in the desert on the left side of the image is the Sixth of October City, an area of factories and residences started by Anwar Sadat to relieve urban crowding. The image was taken on April 19, 1994 by the Spaceborne Imaging Radar-C/X-Band Synthetic Aperture Radar (SIR-C/X-SAR) aboard the shuttle Endeavour. 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. The image is centered on latitude 29.72 degrees North latitude and 30.83 degrees East longitude. The area shown is approximately 20 kilometers by 30 kilometers. 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; green is C-band horizontally transmitted, horizontally received; blue is C-band horizontally transmitted, vertically received.

  3. Pulse pair beamforming and the effects of reflectivity field variations on imaging radars

    NASA Astrophysics Data System (ADS)

    Cheong, Boon Leng; Hoffman, Michael W.; Palmer, Robert D.; Frasier, Stephen J.; López-Dekker, F. J.

    2004-06-01

    Coherent radar imaging (CRI), which is fundamentally a beamforming process, has been used to create images of microscale, reflectivity structures within the resolution volume of atmospheric Doppler radars. This powerful technique has the potential to unlock many new discoveries in atmospheric studies. The Turbulent Eddy Profiler (TEP) is a unique 915 MHz boundary layer radar consisting of a maximum of 91 independent receivers. The TEP configuration allows sophisticated CRI algorithms to be implemented providing significant improvement in angular resolution. The present work includes a thorough simulation study of some of the capabilities of the TEP system. The pulse pair processor, used for radial velocity and spectral width estimation with meteorological radars, is combined with beamforming technique, in an efficient manner, to the imaging radar case. By numerical simulation the new technique is shown to provide robust and computationally efficient estimates of the spectral moments. For this study, a recently developed atmospheric radar simulation method is employed that uses the ten thousand scattering points necessary for the high resolution imaging simulation. Previous methods were limited in the number of scatterers due to complexity issues. Radial velocity images from the beamforming radar are used to estimate the three-dimensional wind field map within the resolution volume. It is shown that a large root mean square (RMS) error in imputed three-dimensional wind fields can occur using standard Fourier imaging. This RMS error does not improve even as SNR is increased. The cause of the error is reflectivity variations within the resolution volume. The finite beamwidth of the beamformer skews the radial velocity estimate, and this results in poor wind field estimates. Adaptive Capon beamforming consistently outperforms the Fourier method in the quantitative study and has been demonstrated to enhance the performance compared to the Fourier method.

  4. Space Radar Image of Rhine River, France and Germany

    NASA Technical Reports Server (NTRS)

    1994-01-01

    This spaceborne radar image shows a segment of the Rhine River where it forms the border between the Alsace region of northeastern France on the left and the Black Forest region of Germany on the right. The Rhine, one of the largest and most used waterways in central Europe, winds its way through five countries from the Swiss-Austrian Alps to the North Sea coast of the Netherlands. The river valley is densely populated, as seen in this image, which shows the French city of Strasbourg, the light blue and orange area in the upper left center; and the German cities of Kehl, across the river from Strasbourg and Offenburg, the bright area in right center. The fertile valley is famous for its wine production and most of the agricultural areas in the image, shown in purple patches, are vineyards. The light green areas are forest. Scientists can use radar images like this one to monitor the effects of urban and agricultural development on sensitive ecosystems such as the Rhine River valley. This image was acquired by the Spaceborne Imaging Radar-C/X-Band Synthetic Aperture Radar (SIR-C/X-SAR) onboard the space shuttle Endeavour on October 2, 1994. The image is 34.2 kilometers by 33.2 kilometers (21.2 miles by 20.6 miles) and is centered at 48.5 degrees north latitude, 7.7 degrees east longitude. North is toward the upper left. The colors are assigned to different radar frequencies and polarizations of the radar as follows: red is L-band, horizontally transmitted and received; green is L-band, horizontally transmitted, vertically received; and blue is C-band, horizontally transmitted, vertically 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 program.

  5. Geologic Studies of Planetary Surfaces Using Radar Polarimetric Imaging

    NASA Technical Reports Server (NTRS)

    Carter, Lynn M.; Campbell, Donald B.; Campbell, Bruce A.

    2010-01-01

    Radar is a useful remote sensing tool for studying planetary geology because it is sensitive to the composition, structure, and roughness of the surface and can penetrate some materials to reveal buried terrain. The Arecibo Observatory radar system transmits a single sense of circular polarization, and both senses of circular polarization are received, which allows for the construction of the Stokes polarization vector. From the Stokes vector, daughter products such as the circular polarization ratio, the degree of linear polarization, and linear polarization angle are obtained. Recent polarimetric imaging using Arecibo has included Venus and the Moon. These observations can be compared to radar data for terrestrial surfaces to better understand surface physical properties and regional geologic evolution. For example, polarimetric radar studies of volcanic settings on Venus, the Moon and Earth display some similarities, but also illustrate a variety of different emplacement and erosion mechanisms. Polarimetric radar data provides important information about surface properties beyond what can be obtained from single-polarization radar. Future observations using polarimetric synthetic aperture radar will provide information on roughness, composition and stratigraphy that will support a broader interpretation of surface evolution.

  6. Space Radar Image of Washington D.C.

    NASA Technical Reports Server (NTRS)

    1994-01-01

    The city of Washington, D.C., is shown is this space radar image. Images like these are useful tools for urban planners and managers, who use them to map and monitor land use patterns. Downtown Washington is the bright area between the Potomac (upper center to lower left) and Anacostia (middle right) rivers. The dark cross shape that is formed by the National Mall, Tidal Basin, the White House and Ellipse is seen in the center of the image. Arlington National Cemetery is the dark blue area on the Virginia (left) side of the Potomac River near the center of the image. The Pentagon is visible in bright white and red, south of the cemetery. Due to the alignment of the radar and the streets, the avenues that form the boundary between Washington and Maryland appear as bright red lines in the top, right and bottom parts of the image, parallel to the image borders. This image is centered at 38.85 degrees north latitude, 77.05 degrees west longitude. North is toward the upper right. The area shown is approximately 29 km by 26 km (18 miles by 16 miles). Colors are assigned to different frequencies and polarizations of the radar as follows: Red is the L-band horizontally transmitted, horizontally received; green is the L-band horizontally transmitted, vertically received; blue is the C-band horizontally transmitted, vertically received. The image was acquired by the Spaceborne Imaging Radar-C/X-band Synthetic Aperture (SIR-C/X-SAR) imaging radar when it flew aboard the space shuttle Endeavour on April 18, 1994. 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 program.

  7. 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.

  8. SAR Image Processing using GPU

    NASA Astrophysics Data System (ADS)

    Shanmugha Sundaram, GA; Sujith Maddikonda, Syam

    Synthetic aperture Radar (SAR) has been extensively used for space-borne Earth observations in recent times. In conventional SAR systems analog beam-steering techniques are capable of implementing multiple operational modes, such as the Stripmap, ScanSAR, and Spotlight, to fulfill the different requirements in terms of spatial resolution and coverage. Future RADAR satellites need to resolve the complex issues such as wide area coverage and resolution. Digital beamforming (DBF) is a promising technique to overcome the problems mentioned above. In communication satellites DBF technique is already implemented. This paper discuses the relevance of DBF in space-borne RADAR satellites for enhancements to quality imaging. To implement DBF in SAR, processing of SAR data is an important step. This work focused on processing of Level 1.1 and 1.5 SAR image data. The SAR raw data is computationally intensive to process. To resolve the computation problem, high performance computing (HPC) is necessary. The relevance of HPC for SAR data processing using an off-the-shelf graphical processing unit (GPU) over CPU is discussed in this paper. Quantitative estimates on SAR image processing performance comparisons using both CPU and GPU are also provided as validation for the results.

  9. Fisheries imaging radar surveillance test /FIRST/ - Bering Sea test

    NASA Technical Reports Server (NTRS)

    Woods, E. G.; Ivey, J. H.

    1977-01-01

    A joint NOAA, U.S. Coast Guard and NASA program is being conducted to determine if a synthetic aperture radar (SAR) system, such as planned for NASA's SEASAT, can be useful in monitoring fishing vessels within the newly established 200-mile fishing limit. As part of this program, data gathering field operations were conducted over concentrations of foreign fishing vessels in the Bering Sea off Alaska in April 1976. The Jet Propulsion Laboratory developed synthetic aperture L-band radar which was flown aboard the NASA Convair 990 aircraft, with a Coast Guard cutter and C-130 aircraft simultaneously gathering data to provide both radar imagery and sea truth information on the vessels being imaged. Results indicate that synthetic aperture radar systems have potential for all weather detection, enumeration and classification of fishing vessels.

  10. Transmitter passband requirements for imaging radar.

    SciTech Connect

    Doerry, Armin Walter

    2012-12-01

    In high-power microwave power amplifiers for radar, distortion in both amplitude and phase should generally be expected. Phase distortions can be readily equalized. Some amplitude distortions are more problematic than others. In general, especially for SAR using LFM chirps, low frequency modulations such as gain slopes can be tolerated much better than multiple cycles of ripple across the passband of the waveform.

  11. Space Radar Image of Orange County, California (annotated version)

    NASA Technical Reports Server (NTRS)

    1994-01-01

    This spaceborne radar image of Orange County, Calif., shows the massive urbanization of this rapidly growing region located just south of Los Angeles. Orange County, sandwiched between rugged mountains and the Pacific Ocean, includes the communities of Anaheim, Santa Ana and Huntington Beach. Anaheim Stadium can be seen in the upper center of the image, as a small white ring to the right of a major freeway intersection. The large dark blue rectangular area in the upper left is the Seal Beach Naval Weapons Station and adjacent wildlife refuge. Runways of the El Toro Marine Air Station appear as a black 'x' near the center of the image. The large purple area to the left of the the Air Station and extending to the coast is the scar left by the Laguna wildfire of October 1993. The sparse vegetation left in the wake of the fire provides a weak source of radar echoes, making the burn areas distinctively dark in the image. Another large burn area, from the Ortega fire of 1993, is seen in the mountains in the lower right of the image. The image was acquired by the Spaceborne Imaging Radar-C/X-band Synthetic Aperture Radar (SIR-C/X-SAR) onboard the space shuttle Endeavour on October 3, 1994. The image is centered at 33.7 degrees north latitude and 117.7 degrees west longitude. North is toward the upper right. The image shows an area 66.2 kilometers by 44.2 kilometers (41.0 miles by 27.4 miles). The colors are assigned todifferent frequencies and polarizations of the radar as follows: red is L-band, horizontally transmitted, horizontally received; green is L-band, horizontally transmitted, vertically received; blue is C-band, horizontally transmitted, vertically 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 program.

  12. Remote sensing with spaceborne synthetic aperture imaging radars: A review

    NASA Technical Reports Server (NTRS)

    Cimino, J. B.; Elachi, C.

    1983-01-01

    A review is given of remote sensing with Spaceborne Synthetic Aperture Radars (SAR's). In 1978, a spaceborne SA was flown on the SEASAT satellite. It acquired high resulution images over many regions in North America and the North Pacific. The acquired data clearly demonstrate the capability of spaceborne SARs to: image and track polar ice floes; image ocean surface patterns including swells, internal waves, current boundaries, weather boundaries and vessels; and image land features which are used to acquire information about the surface geology and land cover. In 1981, another SAR was flown on the second shuttle flight. This Shuttle Imaging Radar (SIR-A) acquired land and ocean images over many areas around the world. The emphasis of the SIR-A experiment was mainly toward geologic mapping. Some of the key results of the SIR-A experiment are given.

  13. Passive synthetic aperture radar imaging of ground moving targets

    NASA Astrophysics Data System (ADS)

    Wacks, Steven; Yazici, Birsen

    2012-05-01

    In this paper we present a method for imaging ground moving targets using passive synthetic aperture radar. A passive radar imaging system uses small, mobile receivers that do not radiate any energy. For these reasons, passive imaging systems result in signicant cost, manufacturing, and stealth advantages. The received signals are obtained by multiple airborne receivers collecting scattered waves due to illuminating sources of opportunity such as commercial television, radio, and cell phone towers. We describe a novel forward model and a corresponding ltered-backprojection type image reconstruction method combined with entropy optimization. Our method determines the location and velocity of multiple targets moving at dierent velocities. Furthermore, it can accommodate arbitrary imaging geometries. we present numerical simulations to verify the imaging method.

  14. Ground-penetrating radar imaging of fluid flow through a discrete fracture

    E-print Network

    Baker, Matthew Peter

    2014-12-31

    surface-based multi-polarization 3-D GPR to examine the effects of radar signal polarization for imaging a fresh-water saturated, millimeter scale subhorizontal fracture. Imaging of a horizontal reflection plane should be independent of radar signal...

  15. Influence of surface material characteristics on laser radar 3D imaging of targets

    NASA Astrophysics Data System (ADS)

    Wang, Biao; Wu, Zhen-Sen; Gong, Yanjun

    2010-11-01

    Characteristics of laser radar (LADAR) 3D image depend on ladar transceivers, propagation effects, target/beam interactions, and data processing or detection algorithms. Process of target/beam interaction is determined by target surface optical scattering properties, which can be characterized by bidirectional reflectivity distribution function (BRDF). Based on alternative monostatic BRDF models, we report here a backscattering model of optical radiation for ladar 3D range image. Atmospheric turbulence effects are not treated.

  16. Subsurface Imaging using Ground-Penetrating Radar Measurements Nathan Goodman, Carl Leuschen, Richard Plumb and Chris Allen

    E-print Network

    Kansas, University of

    Subsurface Imaging using Ground-Penetrating Radar Measurements Nathan Goodman, Carl Leuschen will be a thorough investigation of ground- penetrating radar subsurface imaging techniques, another step toward

  17. Spot restoration for GPR image post-processing

    DOEpatents

    Paglieroni, David W; Beer, N. Reginald

    2014-05-20

    A method and system for detecting the presence of subsurface objects within a medium is provided. In some embodiments, the imaging and detection system operates in a multistatic mode to collect radar return signals generated by an array of transceiver antenna pairs that is positioned across the surface and that travels down the surface. The imaging and detection system pre-processes the return signal to suppress certain undesirable effects. The imaging and detection system then generates synthetic aperture radar images from real aperture radar images generated from the pre-processed return signal. The imaging and detection system then post-processes the synthetic aperture radar images to improve detection of subsurface objects. The imaging and detection system identifies peaks in the energy levels of the post-processed image frame, which indicates the presence of a subsurface object.

  18. A data compression technique for synthetic aperture radar images

    NASA Technical Reports Server (NTRS)

    Frost, V. S.; Minden, G. J.

    1986-01-01

    A data compression technique is developed for synthetic aperture radar (SAR) imagery. The technique is based on an SAR image model and is designed to preserve the local statistics in the image by an adaptive variable rate modification of block truncation coding (BTC). A data rate of approximately 1.6 bit/pixel is achieved with the technique while maintaining the image quality and cultural (pointlike) targets. The algorithm requires no large data storage and is computationally simple.

  19. 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 the National Aeronautics and Space Administration (NASA), the National Imagery and Mapping Agency (NIMA) and the German (DLR) and Italian (ASI) space agencies. It is managed by NASA's Jet Propulsion Laboratory, Pasadena, CA, for NASA's Earth Science Enterprise, Washington, DC.

    Size: 41 km (25 miles) x 29 km (18 miles) Location: 34.1 deg. North lat., 118.3 deg. West lon. Orientation: North toward upper right Original Data Resolution: 30 meters (99 feet) Date Acquired: February 16, 2000

  20. 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 operated in this way, with horizontal resolution of about 5 m and vertical errors less than 2 m. The findings and developments of these earlier investigations are discussed.

  1. Sparse Auto-Calibration for Radar Coincidence Imaging with Gain-Phase Errors.

    PubMed

    Zhou, Xiaoli; Wang, Hongqiang; Cheng, Yongqiang; Qin, Yuliang

    2015-01-01

    Radar coincidence imaging (RCI) is a high-resolution staring imaging technique without the limitation of relative motion between target and radar. The sparsity-driven approaches are commonly used in RCI, while the prior knowledge of imaging models needs to be known accurately. However, as one of the major model errors, the gain-phase error exists generally, and may cause inaccuracies of the model and defocus the image. In the present report, the sparse auto-calibration method is proposed to compensate the gain-phase error in RCI. The method can determine the gain-phase error as part of the imaging process. It uses an iterative algorithm, which cycles through steps of target reconstruction and gain-phase error estimation, where orthogonal matching pursuit (OMP) and Newton's method are used, respectively. Simulation results show that the proposed method can improve the imaging quality significantly and estimate the gain-phase error accurately. PMID:26528981

  2. Registration of a synthetic aperture radar image to Thematic Mapper imagery for remote sensing applications

    NASA Technical Reports Server (NTRS)

    Yao, S. S.; Gilbert, J. R.

    1984-01-01

    Multiple Thematic Mapper multitemporal acquisitions from Landsat and one synthetic-aperture radar acquisition from Seasat have been precisely registered using Johnson Space Center registration processors. The registered images have been output in the Universal Transverse Mercator projection. The procedure to accomplish such disparate data processing tasks and the registration accuracy evaluation are discussed.

  3. A Userfriendly System for Synthetic Aperture Radar Image Classification based on Grayscale Distributional Properties and Context

    E-print Network

    de Figueiredo, Luiz Henrique

    A User­friendly System for Synthetic Aperture Radar Image Classification based on Grayscale and classification of Synthetic Aperture Radar (SAR) images. This system, unlike most of its competitors, allows, system. 1 Introduction Synthetic Aperture Radar (SAR) images are gen­ erated by either airborne

  4. San Gabriel Mountains, California, Radar image, color as height

    NASA Technical Reports Server (NTRS)

    2000-01-01

    This topographic radar image shows the relationship of the urban area of Pasadena, California to the natural contours of the land. The image includes the alluvial plain on which Pasadena and the Jet Propulsion Laboratory sit, and the steep range of the San Gabriel Mountains. The mountain front and the arcuate valley running from upper left to the lower right are active fault zones, along which the mountains are rising. The chaparral-covered slopes above Pasadena are also a prime area for wildfires and mudslides. 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 along the front of active mountain ranges.

    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 blue at the lowest elevations to white at the highest elevations. This image contains about 2300 meters (7500 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-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 (DLR) and Italian (ASI) space agencies. It is managed by NASA's Jet Propulsion Laboratory, Pasadena, CA, for NASA's Earth Science Enterprise, Washington, DC.

    Size: 41 km (25 miles) x 29 km (18 miles) Location: 34.2 deg. North lat., 118.1 deg. West lon. Orientation: North toward upper right Original Data Resolution: 30 meters (99 feet) Date Acquired: February 16, 2000

  5. 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), the National Imagery and Mapping Agency (NIMA) and the German (DLR) and Italian (ASI) space agencies. It is managed by NASA's Jet Propulsion Laboratory, Pasadena, CA, for NASA's Earth Science Enterprise, Washington, DC.

    Size: 56 by 56 kilometers (35 by 35 miles) Location: 21.4 deg. North lat., 157.8 deg. West lon. Orientation: North toward upper left Original Data Resolution: 30 meters (99 feet) Date Acquired: February 18, 2000

  6. Experimental 0.22 THz Stepped Frequency Radar System for ISAR Imaging

    NASA Astrophysics Data System (ADS)

    Liang, Mei Yan; Zhang, Cun Lin; Zhao, Ran; Zhao, Yue Jin

    2014-09-01

    High resolution inverse synthetic aperture radar (ISAR) imaging is demonstrated by using a 0.22 THz stepped-frequency (SF) imaging radar system. The synthesis bandwidth of the terahertz (THz) SF radar is 12 GHz, which are beneficial for high resolution imaging. The resolution of ISAR image can reach centimeter-scale with the use of Range-Doppler algorithm (RDA). Results indicate that high resolution ISAR imaging is realized by using 0.22THz SF radar coupled with turntable scanning, which can provide foundations for further research on high-resolution radar image in the THz band.

  7. Space Radar Image of Great Wall of China

    NASA Technical Reports Server (NTRS)

    1994-01-01

    These radar images show two segments of the Great Wall of China in a desert region of north-central China, about 700 kilometers (434 miles) west of Beijing. The wall appears as a thin orange band, running from the top to the bottom of the left image, and from the middle upper-left to the lower-right of the right image. These segments of the Great Wall were constructed in the 15th century, during the Ming Dynasty. The wall is between 5 and 8 meters high (16 to 26 feet) in these areas. The entire wall is about 3,000 kilometers (1,864 miles) long and about 150 kilometers (93 miles) of the wall appear in these two images. The wall is easily detected from space by radar because its steep, smooth sides provide a prominent surface for reflection of the radar beam. Near the center of the left image, two dry lake beds have been developed for salt extraction. Rectangular patterns in both images indicate agricultural development, primarily wheat fields. The images were acquired by the Spaceborne Imaging Radar-C/X-Band Synthetic Aperture Radar (SIR-C/X-SAR) onboard the space shuttle Endeavour on April 10, 1994. 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. The left image is centered at 37.7 degrees North latitude and 107.5 degrees East longitude. The right image is centered at 37.5 degrees North latitude and 108.1 degrees East longitude. North is toward the upper right. Each area shown measures 25 kilometers by 75 kilometers (15.5 miles by 45.5 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; green is L-band horizontally transmitted, vertically received; blue is C-band horizontally transmitted, vertically received.

  8. 1290 IEEE TRANSACTIONS ON IMAGE PROCESSING, VOL. 19, NO. 5, MAY 2010 Multistatic Synthetic Aperture

    E-print Network

    Yazici, Birsen

    countermeasures that have been devised for monostatic radar are less effective against distributed radar systems1290 IEEE TRANSACTIONS ON IMAGE PROCESSING, VOL. 19, NO. 5, MAY 2010 Multistatic Synthetic Aperture, multistatic, radar, synthetic aperture imagery (SAR). I. INTRODUCTION I N synthetic aperture radar (SAR

  9. A fast 3D image simulation algorithm of moving target for scanning laser radar

    NASA Astrophysics Data System (ADS)

    Li, Jicheng; Shi, Zhiguang; Chen, Xiao; Chen, Dong

    2014-10-01

    Scanning Laser Radar has been widely used in many military and civil areas. Usually there are relative movements between the target and the radar, so the moving target image modeling and simulation is an important research content in the field of signal processing and system design of scan-imaging laser radar. In order to improve the simulation speed and hold the accuracy of the image simulation simultaneously, a novel fast simulation algorithm is proposed in this paper. Firstly, for moving target or varying scene, an inequation that can judge the intersection relations between the pixel and target bins is obtained by deriving the projection of target motion trajectories on the image plane. Then, by utilizing the time subdivision and approximate treatments, the potential intersection relations of pixel and target bins are determined. Finally, the goal of reducing the number of intersection operations could be achieved by testing all the potential relations and finding which of them is real intersection. To test the method's performance, we perform computer simulations of both the new proposed algorithm and a literature's algorithm for six targets. The simulation results show that the two algorithm yield the same imaging result, whereas the number of intersection operations of former is equivalent to only 1% of the latter, and the calculation efficiency increases a hundredfold. The novel simulation acceleration idea can be applied extensively in other more complex application environments and provide equally acceleration effect. It is very suitable for the case to produce a great large number of laser radar images.

  10. Fast high-resolution terahertz radar imaging at 25 meters

    NASA Astrophysics Data System (ADS)

    Cooper, Ken B.; Dengler, Robert J.; Llombart, Nuria; Talukder, Ashit; Panangadan, Anand V.; Peay, Chris S.; Mehdi, Imran; Siegel, Peter H.

    2010-04-01

    We report improvements in the scanning speed and standoff range of an ultra-wide bandwidth terahertz (THz) imaging radar for person-borne concealed object detection. Fast beam scanning of the single-transceiver radar is accomplished by rapidly deflecting a flat, light-weight subreflector in a confocal Gregorian optical geometry. With RF back-end improvements also implemented, the radar imaging rate has increased by a factor of about 30 compared to that achieved previously in a 4 m standoff prototype instrument. In addition, a new 100 cm diameter ellipsoidal aluminum reflector yields beam spot diameters of approximately 1 cm over a 50×50 cm field of view at a range of 25 m, although some aberrations are observed that probably arise from misaligned optics. Through-clothes images of concealed pipes at 25 m range, acquired in 5 seconds, are presented, and the impact of reduced signal-to-noise from an even faster frame rate is analyzed. These results inform the requirements for eventually achieving sub-second or video-rate THz radar imaging.

  11. Fast, High-Resolution Terahertz Radar Imaging at 25 Meters

    NASA Technical Reports Server (NTRS)

    Cooper, Ken B.; Dengler, Robert J.; Llombart, Nuria; Talukder, Ashit; Panangadan, Anand V.; Peay, Chris S.; Siegel, Peter H.

    2010-01-01

    We report improvements in the scanning speed and standoff range of an ultra-wide bandwidth terahertz (THz) imaging radar for person-borne concealed object detection. Fast beam scanning of the single-transceiver radar is accomplished by rapidly deflecting a flat, light-weight subreflector in a confocal Gregorian optical geometry. With RF back-end improvements also implemented, the radar imaging rate has increased by a factor of about 30 compared to that achieved previously in a 4 m standoff prototype instrument. In addition, a new 100 cm diameter ellipsoidal aluminum reflector yields beam spot diameters of approximately 1 cm over a 50x50 cm field of view at a range of 25 m, although some aberrations are observed that probably arise from misaligned optics. Through-clothes images of a concealed threat at 25 m range, acquired in 5 seconds, are presented, and the impact of reduced signal-to-noise from an even faster frame rate is analyzed. These results inform the system requirements for eventually achieving sub-second or video-rate THz radar imaging.

  12. 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.

  13. 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.

  14. Ground-penetrating imaging radar development for bridge deck and road bed inspection

    SciTech Connect

    Warhus, J.P.; Mast, J.E.; Nelson, S.D.; Johansson, E.M.

    1993-05-01

    Ground-penetrating imaging radar (GPIR) is proposed for large-area inspection of concrete and concrete/asphalt composite bridge decks and roadways. This technique combines ground-penetrating radar (GPR) with unique image reconstruction algorithms developed for identification and characterization of subsurface flaws and structural features. New data acquisition hardware and image reconstruction techniques, under development at LLNL, offer the possibility for reliable and efficient, high-resolution subsurface imaging through the use of improved ultra-wideband transmitters, antennas, and arrays, and enhanced image- and signal-processing software. A field test of a limited-capability prototype system is planned for FY-93, as is completion of a conceptual design for a practical inspection system. A follow-on program for FY-94 would focus on development and demonstration of an advanced bridge inspection system prototype based on the conceptual design completed during FY-93.

  15. Microwave Radar Imaging of Heterogeneous Breast Tissue Integrating A Priori Information

    PubMed Central

    Kelly, Thomas N.; Sarafianou, Mantalena; Craddock, Ian J.

    2014-01-01

    Conventional radar-based image reconstruction techniques fail when they are applied to heterogeneous breast tissue, since the underlying in-breast relative permittivity is unknown or assumed to be constant. This results in a systematic error during the process of image formation. A recent trend in microwave biomedical imaging is to extract the relative permittivity from the object under test to improve the image reconstruction quality and thereby to enhance the diagnostic assessment. In this paper, we present a novel radar-based methodology for microwave breast cancer detection in heterogeneous breast tissue integrating a 3D map of relative permittivity as a priori information. This leads to a novel image reconstruction formulation where the delay-and-sum focusing takes place in time rather than range domain. Results are shown for a heterogeneous dense (class-4) and a scattered fibroglandular (class-2) numerical breast phantom using Bristol's 31-element array configuration. PMID:25435861

  16. Space Radar Image of Kilauea, Hawaii in 3-D

    NASA Technical Reports Server (NTRS)

    1999-01-01

    This is a three-dimensional perspective view of a false-color image of the eastern part of the Big Island of Hawaii. It was produced using all three radar frequencies -- X-band, C-band and L-band -- from the Spaceborne Imaging Radar-C/X-Band Synthetic Aperture Radar (SIR-C/X-SAR) flying on the space shuttle Endeavour, overlaid on a U.S. Geological Survey digital elevation map. Visible in the center of the image in blue are the summit crater (Kilauea Caldera) which contains the smaller Halemaumau Crater, and the line of collapse craters below them that form the Chain of Craters Road. The image was acquired on April 12, 1994 during orbit 52 of the space shuttle. The area shown is approximately 34 by 57 kilometers (21 by 35 miles) with the top of the image pointing toward northwest. The image is centered at about 155.25 degrees west longitude and 19.5 degrees north latitude. The false colors are created by displaying three radar channels of different frequency. Red areas correspond to high backscatter at L-HV polarization, while green areas exhibit high backscatter at C-HV polarization. Finally, blue shows high return at X-VV polarization. Using this color scheme, the rain forest appears bright on the image, while the green areas correspond to lower vegetation. The lava flows have different colors depending on their types and are easily recognizable due to their shapes. The flows at the top of the image originated from the Mauna Loa volcano. 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-quartermile) inland from the coast. A moving lava flow about 200 meters (650 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. Currently, most of the lava that is erupted travels the 8 kilometers (5 miles) from the Pu'u O'o crater (the active vent) just outside this image to the coast through a series of lava tubes, but in the past there have been many large lava flows that have traveled this distance, destroying houses and parts of the Hawaii Volcanoes National Park. This SIR-C/X-SAR image shows two types of lava flows that are common to Hawaiian volcanoes. Pahoehoe lava flows are relatively smooth, and appear very dark blue because much of the radar energy is reflected away from the radar. In contrast other lava flows are relatively rough and bounce much of the radar energy back to the radar, making that part of the image bright blue. This radar image is valuable because it allows scientists to study an evolving lava flow field from the Pu'u O'o vent. Much of the area on the northeast side (right) of the volcano is covered with tropical rain forest, and because trees reflect a lot of the radar energy, the forest appears bright in this radar scene. The linear feature running from Kilauea Crater to the right of the image is Highway 11leading to the city of Hilo which is located just beyond the right edge of this image. 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)

  17. Space Radar Image of Craters of the Moon, Idaho

    NASA Technical Reports Server (NTRS)

    1994-01-01

    Ancient lava flows dating back 2,000 to 15,000 years are shown in light green and red on the left side of this space radar image of the Craters of the Moon National Monument area in Idaho. The volcanic cones that produced these lava flows are the dark points shown within the light green area. Craters of the Moon National Monument is part of the Snake River Plain volcanic province. Geologists believe this area was formed as the North American tectonic plate moved across a 'hot spot' which now lies beneath Yellowstone National Park. The irregular patches, shown in red, green and purple in the lower half of the image are lava flows of different ages and surface roughnesses. One of these lava flows is surrounded by agricultural fields, the blue and purple geometric features, in the right center of the image. The town of Arco, Idaho is the bright yellow area on the right side of the agricultural area. The peaks along the top of the image are the White Knob Mountains. The Big Lost River flows out of the canyon at the top right of the image. The image was acquired by the Spaceborne Imaging Radar-C/X-band Synthetic Aperture Radar (SIR-C/X-SAR) when it flew aboard the space shuttle Endeavour on October 5, 1994. This image is centered at 43.58 degrees north latitude, 113.42 degrees west longitude. The area shown is approximately 33 kilometers by 48 kilometers 20.5 miles by 30 miles). Colors are assigned to different frequencies and polarizations of the radar as follows: red is the L-band horizontally transmitted, horizontally received; green is the L-band horizontally transmitted, vertically received; blue is the C-band horizontally transmitted, vertically 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 program.

  18. An Approach for Sub-Second Imaging of Concealed Objects Using Terahertz (THz) Radar

    NASA Astrophysics Data System (ADS)

    Cooper, K. B.; Dengler, R. J.; Llombart, N.; Bryllert, T.; Chattopadhyay, G.; Mehdi, I.; Siegel, P. H.

    2009-12-01

    High-resolution, long-range detection of person-borne concealed weapons has recently been demonstrated using a terahertz imaging radar. However, the radar’s image acquisition time must be greatly shortened, from minutes to less than one second, before the system can be effectively deployed in a real-life threat environment. Here we analyze the major system modifications necessary for increasing the speed of a terahertz imaging radar by up to two orders of magnitude.

  19. Radar Image with Color as Height, Ancharn Kuy, Cambodia

    NASA Technical Reports Server (NTRS)

    2002-01-01

    This image of Ancharn Kuy, Cambodia, was taken by NASA's Airborne Synthetic Aperture Radar (AIRSAR). The image depicts an area northwest of Angkor Wat. The radar has highlighted a number of circular village mounds in this region, many of which have a circular pattern of rice fields surrounding the slightly elevated site. Most of them have evidence of what seems to be pre-Angkor occupation, such as stone tools and potsherds. Most of them also have a group of five spirit posts, a pattern not found in other parts of Cambodia. The shape of the mound, the location in the midst of a ring of rice fields, the stone tools and the current practice of spirit veneration have revealed themselves through a unique 'marriage' of radar imaging, archaeological investigation, and anthropology.

    Ancharn Kuy is a small village adjacent to the road, with just this combination of features. The region gets slowly higher in elevation, something seen in the shift of color from yellow to blue as you move to the top of the image.

    The small dark rectangles are typical of the smaller water control devices employed in this area. While many of these in the center of Angkor are linked to temples of the 9th to 14th Century A.D., we cannot be sure of the construction date of these small village tanks. They may pre-date the temple complex, or they may have just been dug ten years ago!

    The image dimensions are approximately 4.75 by 4.3 kilometers (3 by 2.7 miles) with a pixel spacing of 5 meters (16.4 feet). North is at top. Image brightness is from the C-band (5.6 centimeters, or 2.2 inches) wavelength radar backscatter, which is a measure of how much energy the surface reflects back toward the radar. Color is used to represent elevation contours. One cycle of color; that is going from blue to red to yellow to green and back to blue again; corresponds to 10 meters (32.8 feet) of elevation change.

    AIRSAR flies aboard a NASA DC-8 based at NASA's Dryden Flight Research Center, Edwards, Calif. In the TOPSAR mode, AIRSAR collects radar interferometry data from two spatially separated antennas (2.6 meters, or 8.5 feet). Information from the two antennas is used to form radar backscatter imagery and to generate highly accurate elevation data. Built, operated and managed by JPL, AIRSAR is part of NASA's Earth Science Enterprise program. JPL is a division of the California Institute of Technology in Pasadena.

  20. Real-time implementation of frequency-modulated continuous-wave synthetic aperture radar imaging using field programmable gate array.

    PubMed

    Quan, Yinghui; Li, Yachao; Hu, Guibin; Xing, Mengdao

    2015-06-01

    A new miniature linear frequency-modulated continuous-wave radar which mounted on an unmanned aerial vehicle is presented. It allows the accomplishment of high resolution synthetic aperture radar imaging in real-time. Only a Kintex-7 field programmable gate array from Xilinx is utilized for whole signal processing of sophisticated radar imaging algorithms. The proposed hardware architecture achieves remarkable improvement in integration, power consumption, volume, and computing performance over its predecessor designs. The realized design is verified by flight campaigns. PMID:26133857

  1. Distortion effects in a switch array UWB radar for time-lapse imaging of human heartbeats

    NASA Astrophysics Data System (ADS)

    Brovoll, Sverre; Berger, Tor; Aardal, Åyvind; Lande, Tor S.; Hamran, Svein-Erik

    2014-05-01

    Cardiovascular diseases (CVD) are a major cause of deaths all over the world. Microwave radar can be an alternative sensor for heart diagnostics and monitoring in modern healthcare that aids early detection of CVD symptoms. In this paper measurements from a switch array radar system are presented. This UWB system operates below 3 GHz and does time-lapse imaging of the beating heart inside the human body. The array consists of eight fat dipole elements. With a switch system, every possible sequence of transmit/receive element pairs can be selected to build a radar image from the recordings. To make the radar waves penetrate the human tissue, the antenna array is placed in contact with the body. Removal of the direct signal leakage through the antennas and body surface are done by high-pass (HP) filtering of the data prior to image processing. To analyze the results, measurements of moving spheres in air and simulations are carried out. We see that removal of the direct signal introduces amplitude distortion in the images. In addition, the effect of small target motion between the collection times of data from the individual elements is analyzed. With low pulse repetition frequency (PRF) this motion will distort the image. By using data from real measurements of heart motion in simulations, we analyze how the PRF and the antenna geometry influence this distortions.

  2. New Orleans Topography, Radar Image with Colored Height

    NASA Technical Reports Server (NTRS)

    2005-01-01

    [figure removed for brevity, see original site] Click on the image for the animation

    About the animation: This simulated view of the potential effects of storm surge flooding on Lake Pontchartrain and the New Orleans area was generated with data from the Shuttle Radar Topography Mission. Although it is protected by levees and sea walls against storm surges of 18 to 20 feet, much of the city is below sea level, and flooding due to storm surges caused by major hurricanes is a concern. The animation shows regions that, if unprotected, would be inundated with water. The animation depicts flooding in one-meter increments.

    About the image: The city of New Orleans, situated on the southern shore of Lake Pontchartrain, is shown in this radar image from the Shuttle Radar Topography Mission (SRTM). In this image bright areas show regions of high radar reflectivity, such as from urban areas, and elevations have been coded in color using height data also from the SRTM mission. Dark green colors indicate low elevations, rising through yellow and tan, to white at the highest elevations.

    New Orleans is near the center of this scene, between the lake and the Mississippi River. The line spanning the lake is the Lake Pontchartrain Causeway, the world's longest overwater highway bridge. Major portions of the city of New Orleans are actually below sea level, and although it is protected by levees and sea walls that are designed to protect against storm surges of 18 to 20 feet, flooding during storm surges associated with major hurricanes is a significant concern.

    Data used in this image were acquired by the Shuttle Radar Topography Mission aboard the Space Shuttle Endeavour, launched on Feb. 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 3-D measurements of the Earth's surface. To collect the 3-D data, engineers added a 60-meter (approximately 200-foot) mast, installed additional C-band and X-band antennas, and improved tracking and navigation devices. The mission is a cooperative project between NASA, the National Geospatial-Intelligence Agency (NGA) of the U.S. Department of Defense and the German and Italian space agencies. It is managed by NASA's Jet Propulsion Laboratory, Pasadena, Calif., for NASA's Science Mission Directorate, Washington, D.C.

    Location: 30.2 degrees North latitude, 90.1 degrees East longitude Orientation: North toward the top, Mercator projection Size: 80.3 by 68.0 kilometers (49.9 by 42.3 miles) Image Data: Radar image and colored Shuttle Radar Topography Mission elevation model Date Acquired: February 2000

  3. Thermally Enhanced Photoacoustic Radar Imaging of Biotissues

    NASA Astrophysics Data System (ADS)

    Wang, Wei; Mandelis, Andreas

    2015-06-01

    The signal-to-noise ratio (SNR) and imaging depth of photoacoustic (PA) imaging remain limited for clinical applications. The temperature can influence PA signals; the SNR of PA signals can be increased at higher temperatures. Therefore, the imaging quality and depth can be improved by the assistance of heating. Experimental results showed that the maximum imaging depth can be doubled by raising the temperature of the absorbers ( ex-vivo beef muscle) uniformly from to , and the SNR can be increased.

  4. Space Radar Image of Calcutta, West Bengal, India

    NASA Technical Reports Server (NTRS)

    1994-01-01

    This radar image of Calcutta, India, illustrates different urban land use patterns. Calcutta, the largest city in India, is located on the banks of the Hugli River, shown as the thick, dark line in the upper portion of the image. The surrounding area is a flat swampy region with a subtropical climate. As a result of this marshy environment, Calcutta is a compact city, concentrated along the fringes of the river. The average elevation is approximately 9 meters (30 feet) above sea level. Calcutta is located 154 kilometers (96 miles) upstream from the Bay of Bengal. Central Calcutta is the light blue and orange area below the river in the center of the image. The bridge spanning the river at the city center is the Howrah Bridge which links central Calcutta to Howrah. The dark region just below the river and to the left of the city center is Maidan, a large city park housing numerous cultural and recreational facilities. The international airport is in the lower right of the image. The bridge in the upper right is the Bally Bridge which links the suburbs of Bally and Baranagar. This image is 30 kilometers by 10 kilometers (19 miles by 6 miles)and is centered at 22.3 degrees north latitude, 88.2 degrees east longitude. North is toward the upper right. The colors are assigned to different radar frequencies and polarizations as follows: red is L-band, horizontally transmitted and received; green is L-band, horizontally transmitted and vertically received; and blue is C-band, horizontally transmitted and vertically received. The image was acquired by the Spaceborne Imaging Radar-C/X-band Synthetic Aperture Radar (SIR-C/X-SAR) on October 5, 1994, onboard the Space Shuttle Endeavour. 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 program.

  5. Ultra wideband ground penetrating radar imaging of heterogeneous solids

    DOEpatents

    Warhus, J.P.; Mast, J.E.

    1998-11-10

    A non-invasive imaging system for analyzing engineered structures comprises pairs of ultra wideband radar transmitters and receivers in a linear array that are connected to a timing mechanism that allows a radar echo sample to be taken at a variety of delay times for each radar pulse transmission. The radar transmitters and receivers are coupled to a position determining system that provides the x,y position on a surface for each group of samples measured for a volume from the surface. The radar transmitter and receivers are moved about the surface, e.g., attached to the bumper of a truck, to collect such groups of measurements from a variety of x,y positions. Return signal amplitudes represent the relative reflectivity of objects within the volume and the delay in receiving each signal echo represents the depth at which the object lays in the volume and the propagation speeds of the intervening material layers. Successively deeper z-planes are backward propagated from one layer to the next with an adjustment for variations in the expected propagation velocities of the material layers that lie between adjacent z-planes. 11 figs.

  6. Ultra wideband ground penetrating radar imaging of heterogeneous solids

    DOEpatents

    Warhus, John P. (Brentwood, CA); Mast, Jeffrey E. (Livermore, CA)

    1998-01-01

    A non-invasive imaging system for analyzing engineered structures comprises pairs of ultra wideband radar transmitters and receivers in a linear array that are connected to a timing mechanism that allows a radar echo sample to be taken at a variety of delay times for each radar pulse transmission. The radar transmitters and receivers are coupled to a position determining system that provides the x,y position on a surface for each group of samples measured for a volume from the surface. The radar transmitter and receivers are moved about the surface, e.g., attached to the bumper of a truck, to collect such groups of measurements from a variety of x,y positions. Return signal amplitudes represent the relative reflectivity of objects within the volume and the delay in receiving each signal echo represents the depth at which the object lays in the volume and the propagation speeds of the intervening material layers. Successively deeper z-planes are backward propagated from one layer to the next with an adjustment for variations in the expected propagation velocities of the material layers that lie between adjacent z-planes.

  7. Signal Processing System for the CASA Integrated Project I Radars

    SciTech Connect

    Bharadwaj, Nitin; Chandrasekar, V.; Junyent, Francesc

    2010-09-01

    This paper describes the waveform design space and signal processing system for dual-polarization Doppler weather radar operating at X band. The performance of the waveforms is presented with ground clutter suppression capability and mitigation of range velocity ambiguity. The operational waveform is designed based on operational requirements and system/hardware requirements. A dual Pulse Repetition Frequency (PRF) waveform was developed and implemented for the first generation X-band radars deployed by the Center for Collaborative Adaptive Sensing of the Atmosphere (CASA). This paper presents an evaluation of the performance of the waveforms based on simulations and data collected by the first-generation CASA radars during operations.

  8. Hurricane Rita Track Radar Image with Topographic Overlay

    NASA Technical Reports Server (NTRS)

    2005-01-01

    [figure removed for brevity, see original site] Animation

    About the animation: This simulated view of the potential effects of storm surge flooding on Galveston and portions of south Houston was generated with data from the Shuttle Radar Topography Mission. Although it is protected by a 17-foot sea wall against storm surges, flooding due to storm surges caused by major hurricanes remains a concern. The animation shows regions that, if unprotected, would be inundated with water. The animation depicts flooding in one-meter increments.

    About the image: The Gulf Coast from the Mississippi Delta through the Texas coast is shown in this satellite image from NASA's Moderate Resolution Imaging Spectroradiometer (MODIS) overlain with data from the Shuttle Radar Topography Mission (SRTM), and the predicted storm track for Hurricane Rita. The prediction from the National Weather Service was published Sept. 22 at 4 p.m. Central Time, and shows the expected track center in black with the lighter shaded area indicating the range of potential tracks the storm could take.

    Low-lying terrain along the coast has been highlighted using the SRTM elevation data, with areas within 15 feet of sea level shown in red, and within 30 feet in yellow. These areas are more at risk for flooding and the destructive effects of storm surge and high waves.

    Data used in this image were acquired by the Shuttle Radar Topography Mission aboard the Space Shuttle Endeavour, launched on Feb. 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 3-D measurements of the Earth's surface. To collect the 3-D data, engineers added a 60-meter (approximately 200-foot) mast, installed additional C-band and X-band antennas, and improved tracking and navigation devices. The mission is a cooperative project between NASA, the National Geospatial-Intelligence Agency (NGA) of the U.S. Department of Defense and the German and Italian space agencies. It is managed by NASA's Jet Propulsion Laboratory, Pasadena, Calif., for NASA's Science Mission Directorate, Washington, D.C.

    Location: 28 degrees North latitude, 23.5 degrees West longitude Orientation: North toward the top Size:890 by 1447 kilometers (552 by 897 miles) Image Data: MODIS image and colored SRTM elevation model Date Acquired: February 2000

  9. 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.

  10. (To appear in Optical Engineering) An Automated Stokesmetric Imaging Laser Radar

    E-print Network

    Shahriar, Selim

    . Introduction #12;2 Laser radar, also referred to as LADAR or LIDAR, uses eye-safe lasers to measure the range1 (To appear in Optical Engineering) An Automated Stokesmetric Imaging Laser Radar System Xue Liu1-speed, automated laser radar (LADAR) system with sensitivity enhanced by polarimetric imaging technique. This LADAR

  11. Multidimensional Cloud Images Retrieval From Dual-Frequency Millimeter-Wave Radar

    E-print Network

    Cruz-Pol, Sandra L.

    use radar scans of cloud reflectivity at 33 GHz and 95 GHz to produce multi-dimensional cloud images such as the General Circulation Models (GCMs)[9]. The cloud reflectivity was measured with the Cloud Profiling RadarMultidimensional Cloud Images Retrieval From Dual- Frequency Millimeter-Wave Radar Sandra L. Cruz

  12. Region-enhanced passive radar imaging M. C etin and A.D. Lanterman

    E-print Network

    Yanikoglu, Berrin

    target recognition. This provides an alternative to the radar cross-section signature-based automaticRegion-enhanced passive radar imaging M. C¸ etin and A.D. Lanterman Abstract: The authors adapt and apply a recently-developed region-enhanced synthetic aperture radar (SAR) image reconstruction technique

  13. 2 1 APPLICATION GALLERY 1.1 Tracking ``Fuzzy'' Storms in Doppler Radar Images

    E-print Network

    Barron, John

    2 1 APPLICATION GALLERY 1.1 Tracking ``Fuzzy'' Storms in Doppler Radar Images J. L. Barron 1 , R. E. 2 King City Radar Station, Atmospheric Environmental Services, Canada. Problem statement. Because radar images. Since 1985, the Cloud Physics Research Division of AES (Atmospheric Environment Service

  14. Multi-frequency fine resolution imaging radar instrumentation and data acquisition. [side-looking radar for airborne imagery

    NASA Technical Reports Server (NTRS)

    Rendleman, R. A.; Champagne, E. B.; Ferris, J. E.; Liskow, C. L.; Marks, J. M.; Salmer, R. J.

    1974-01-01

    Development of a dual polarized L-band radar imaging system to be used in conjunction with the present dual polarized X-band radar is described. The technique used called for heterodyning the transmitted frequency from X-band to L-band and again heterodyning the received L-band signals back to X-band for amplification, detection, and recording.

  15. Space Radar Image of Santa Cruz Island, California

    NASA Technical Reports Server (NTRS)

    1994-01-01

    This space radar image shows the rugged topography of Santa Cruz Island, part of the Channel Islands National Park in the Pacific Ocean off the coast of Santa Barbara and Ventura, Calif. Santa Cruz, the largest island of the national park, is host to hundreds of species of plants, animals and birds, at least eight of which are known nowhere else in the world. The island is bisected by the Santa Cruz Island fault, which appears as a prominent line running from the upper left to the lower right in this image. The fault is part of the Transverse Range fault system, which extends eastward from this area across Los Angeles to near Palm Springs, Calif. Color variations in this image are related to the different types of vegetation and soils at the surface. For example, grass-covered coastal lowlands appear gold, while chaparral and other scrub areas appear pink and blue. The image is 35 kilometers by 32 kilometers (22 miles by 20 miles) and is centered at 33.8 degrees north latitude, 119.6 degrees west longitude. North is toward upper right. The colors are assigned to different radar frequencies and polarizations as follows: red is L-band, horizontally transmitted and received; green is C-band, horizontally transmitted and received; and blue is C-band, horizontally transmitted and vertically received. The image was acquired by the Spaceborne Imaging Radar-C/X-band Synthetic Aperture Radar (SIR-C/X-SAR) on October 10, 1994, onboard the space shuttle Endeavour. 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 program.

  16. Space Radar Image of Sakura-Jima Volcano, Japan

    NASA Technical Reports Server (NTRS)

    1994-01-01

    The active volcano Sakura-Jima on the island of Kyushu, Japan is shown in the center of this radar image. The volcano occupies the peninsula in the center of Kagoshima Bay, which was formed by the explosion and collapse of an ancient predecessor of today's volcano. The volcano has been in near continuous eruption since 1955. Its explosions of ash and gas are closely monitored by local authorities due to the proximity of the city of Kagoshima across a narrow strait from the volcano's center, shown below and to the left of the central peninsula in this image. City residents have grown accustomed to clearing ash deposits from sidewalks, cars and buildings following Sakura-jima's eruptions. The volcano is one of 15 identified by scientists as potentially hazardous to local populations, as part of the international 'Decade Volcano' program. The image was acquired by the Spaceborne Imaging Radar-C/X-Band Synthetic Aperture Radar (SIR-C/X-SAR) onboard the space shuttle Endeavour on October 9, 1994. 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. The image is centered at 31.6 degrees North latitude and 130.6 degrees East longitude. North is toward the upper left. The area shown measures 37.5 kilometers by 46.5 kilometers (23.3 miles by 28.8 miles). The colors in the image are assigned to different frequencies and polarizations of the radar as follows: red is L-band vertically transmitted, vertically received; green is the average of L-band vertically transmitted, vertically received and C-band vertically transmitted, vertically received; blue is C-band vertically transmitted, vertically received.

  17. Image Visualization Medical Image Processing

    E-print Network

    Wu, Xiaolin

    Image Visualization ENG4BF3 Medical Image Processing #12;2 Visualization Methods · Visualization of medical images is for the determination of the quantitative information about the properties of anatomic types) #12;3 Two-dimensional Image Generation and Visualization · The utility of 2D images depends

  18. SRTM Radar Image with Color as Height: Kachchh, Gujarat, India

    NASA Technical Reports Server (NTRS)

    2001-01-01

    This image shows the area around the January 26, 2001, earthquake in western India, the deadliest in the country's history with some 20,000 fatalities. The epicenter of the magnitude 7.6 earthquake was just to the left of the center of the image. The Gulf of Kachchh (or Kutch) is the black area running from the lower left corner towards the center of the image. The city of Bhuj is in the yellow-toned area among the brown hills left of the image center and is the historical capital of the Kachchh region. Bhuj and many other towns and cities nearby were almost completely destroyed by the shaking of the earthquake. These hills reach up to 500 meters (1,500 feet) elevation. The city of Ahmedabad, capital of Gujarat state, is the radar-bright area next to the right side of the image. Several buildings in Ahmedabad were also destroyed by the earthquake. The dark blue areas around the center of the image and extending to the left side are low-lying salt flats called the Rann of Kachchh with the Little Rann just to the right of the image center. The bumpy area north of the Rann (green and yellow colors) is a large area of sand dunes in Pakistan. A branch of the Indus River used to flow through the area on the left side of this image, but it was diverted by a previous large earthquake that struck this area in 1819.

    The annotated version of the image includes a 'beachball' that shows the location and slip direction of the January 26, 2001, earthquake from the Harvard Quick CMT catalog: http://www.seismology.harvard.edu/CMTsearch.html. [figure removed for brevity, see original site]

    This image combines two types of data from the Shuttle Radar Topography Mission (SRTM). 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 blue at the lowest elevations to brown and white at the highest elevations. This image is a mosaic of four SRTM swaths.

    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: 450 by 300 kilometers (280 by 190 miles) Location: 23.5 deg. North lat., 70.5 deg. East lon. Orientation: North up Original Data Resolution: SRTM 30 meters (99 feet) Date Acquired: four days in February, 2000

  19. An information theory characterization of radar images and a new definition for radiometric resolution

    NASA Technical Reports Server (NTRS)

    Frost, V. S.; Shanmugan, K. S.; Holtzman, J. C.

    1982-01-01

    The noise properties of the radar image formation process are used in the present modeling of a communication channel in which the desired target properties are the information transmitted, and the final image represents the received signal. The average information rate over this communication channel is calculated together with appropriate bounds and approximations, and is found to be small on a per-sample basis. As a result, many samples must be averaged to allow for the discrimination, or classification, of several levels of target reflectivity. These information rate properties are consistent with known results concerning target detection and image quality in speckle, and the rate is applicable to the definition of radar image radiometric resolution. Radiometric resolution is functionally related to the degree of noncoherent averaging performed by the sensor.

  20. A systematic search for undiscovered companions to near-Earth asteroids in radar images

    NASA Astrophysics Data System (ADS)

    Bowman, M. Oliver; Margot, Jean-Luc

    2015-11-01

    Radar observations have been paramount to the characterization of small (<20 km) Near-Earth Objects (NEOs), specifically with regards to asteroid trajectories, shapes, spins, and multi-component systems. Binary systems make up a sizable fraction (~16%) of the asteroid population in near-Earth space. Their formation process is understood to be rotational fission caused by the YORP effect. Possible outcomes of post-fission dynamics include contact binaries, tightly and loosely bound binaries, and asteroid pairs. Radar images have been used to identify asteroid satellites that orbit near the primary component, but relatively little attention has been paid to the detection of more distant satellites. We are conducting a systematic search for faint and/or distant satellites in the Arecibo radar data archive. To this end, we have developed a software package to identify candidate objects in radar images and to differentiate these candidates from background noise using statistical analysis; preliminary results of the search will be presented at the meeting. Possible future applications include systematic measurements of asteroid radar properties (e.g., Doppler and range extents) that could become part of an automated data reduction pipeline.

  1. Shuttle Imaging Radar - Physical controls on signal penetration and subsurface scattering in the Eastern Sahara

    NASA Technical Reports Server (NTRS)

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

    1986-01-01

    Interpretation of Shuttle Imaging Radar-A (SIR-A) images by McCauley et al. (1982) dramatically changed previous concepts of the role that fluvial processes have played over the past 10,000 to 30 million years in shaping this now extremely flat, featureless, and hyperarid landscape. In the present paper, the near-surface stratigraphy, the electrical properties of materials, and the types of radar interfaces found to be responsible for different classes of SIR-A tonal response are summarized. The dominant factors related to efficient microwave signal penetration into the sediment blanket include (1) favorable distribution of particle sizes, (2) extremely low moisture content and (3) reduced geometric scattering at the SIR-A frequency (1.3 GHz). The depth of signal penetration that results in a recorded backscatter, here called 'radar imaging depth', was documented in the field to be a maximum of 1.5 m, or 0.25 of the calculated 'skin depth', for the sediment blanket. Radar imaging depth is estimated to be between 2 and 3 m for active sand dune materials. Diverse permittivity interfaces and volume scatterers within the shallow subsurface are responsible for most of the observed backscatter not directly attributable to grazing outcrops. Calcium carbonate nodules and rhizoliths concentrated in sandy alluvium of Pleistocene age south of Safsaf oasis in south Egypt provide effective contrast in premittivity and thus act as volume scatterers that enhance SIR-A portrayal of younger inset stream channels.

  2. A comparison of spotlight synthetic aperture radar image formation techniques

    SciTech Connect

    Knittle, C.D.; Doren, N.E.; Jakowatz, C.V.

    1996-10-01

    Spotlight synthetic aperture radar images can be formed from the complex phase history data using two main techniques: (1) polar-to-cartesian interpolation followed by two-dimensional inverse Fourier transform (2DFFT), and (2) convolution backprojection (CBP). CBP has been widely used to reconstruct medical images in computer aided tomography, and only recently has been applied to form synthetic aperture radar imagery. It is alleged that CBP yields higher quality images because (1) all the Fourier data are used and (2) the polar formatted data is used directly to form a 2D Cartesian image and therefore 2D interpolation is not required. This report compares the quality of images formed by CBP and several modified versions of the 2DFFT method. We show from an image quality point of view that CBP is equivalent to first windowing the phase history data and then interpolating to an exscribed rectangle. From a mathematical perspective, we should expect this conclusion since the same Fourier data are used to form the SAR image. We next address the issue of parallel implementation of each algorithm. We dispute previous claims that CBP is more readily parallelizable than the 2DFFT method. Our conclusions are supported by comparing execution times between massively parallel implementations of both algorithms, showing that both experience similar decreases in computation time, but that CBP takes significantly longer to form an image.

  3. Space Radar Image of Death Valley in 3-D

    NASA Technical Reports Server (NTRS)

    1999-01-01

    This picture is a three-dimensional perspective view of Death Valley, California. This view was constructed by overlaying a SIR-C radar image on a U.S. Geological Survey digital elevation map. The SIR-C image is centered at 36.629 degrees north latitude and 117.069 degrees west longitude. We are looking at Stove Pipe Wells, which is the bright rectangle located in the center of the picture frame. Our vantage point is located atop a large alluvial fan centered at the mouth of Cottonwood Canyon. In the foreground on the left, we can see the sand dunes near Stove Pipe Wells. In the background on the left, the Valley floor gradually falls in elevation toward Badwater, the lowest spot in the United States. In the background on the right we can see Tucki Mountain. This SIR-C/X-SAR supersite is an area of extensive field investigations and has been visited by both Space Radar Lab astronaut crews. Elevations in the Valley range from 70 meters (230 feet) below sea level, the lowest in the United States, to more than 3,300 meters (10,800 feet) above sea level. Scientists are using SIR-C/X-SAR data from Death Valley to help the answer a number of different questions about Earth's geology. One question concerns how alluvial fans are formed and change through time under the influence of climatic changes and earthquakes. Alluvial fans are gravel deposits that wash down from the mountains over time. They are visible in the image as circular, fan-shaped bright areas extending into the darker valley floor from the mountains. Information about the alluvial fans helps scientists study Earth's ancient climate. Scientists know the fans are built up through climatic and tectonic processes and they will use the SIR-C/X-SAR data to understand the nature and rates of weathering processes on the fans, soil formation and the transport of sand and dust by the wind. SIR-C/X-SAR's sensitivity to centimeter-scale (inch-scale) roughness provides detailed maps of surface texture. Such information can be used to study the occurrence and movement of dust storms and sand dunes. The goal of these studies is to gain a better understanding of the record of past climatic changes and the effects of those changes on a sensitive environment. This may lead to a better ability to predict future response of the land to different potential global climate-change scenarios. Vertical exaggeration is 1.87 times; exaggeration of relief is a common tool scientists use to detect relationships between structure (for example, faults and fractures) and topography. Death Valley is also one of the primary calibration sites for SIR-C/X-SAR. In the lower right quadrant of the picture frame two bright dots can be seen which form a line extending to Stove Pipe Wells. These dots are corner reflectors that have been set up to calibrate the radar as the shuttle passes overhead. Thirty triangular-shaped reflectors (they look like aluminum pyramids) have been deployed by the calibration team from JPL over a 40- by 40-kilometer (25- by 25-mile) area in and around Death Valley. The signatures of these reflectors were analyzed by JPL scientists to calibrate the image used in this picture. The calibration team here also deployed transponders (electronic reflectors) and receivers to measure the radar signals from SIR-C/X-SAR on the ground. SIR-C/X-SAR 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, in conjunction with 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

  4. Imaging targets embedded in a lossy half space with Synthetic Aperture Radar

    SciTech Connect

    Doerry, A.W.; Brock, B.C.; Boverie, B.; Cress, D.

    1994-05-01

    This paper addresses theoretical aspects of forming images from an airborne Synthetic Aperture Radar (SAR) of targets buried below the earth`s surface. Soil is generally a lossy, dispersive medium, with wide ranging variability in these attributes depending on soil type, moisture content, and a host of other physical properties. Focussing a SAR subsurface image presents new dimensions of complexity relative to its surface-image counterpart, even when the soil`s properties are known. This paper treats the soil as a lossy, dispersive half space, and presents a practical model for the radar echo-delay time to point scatterers within it. This model is then used to illustrate effects of refraction, dispersion, and attenuation on a SAR`s phase histories, and the resulting image. Various data collection geometries and processing strategies are examined for both 2-Dimensional and 3-Dimensional SAR images. The conclusions from this work are that (1) focussing a SAR image must generally take into account both refraction and dispersion, (2) resolving targets at different depths in lossy soils requires perhaps unprecedented sidelobe attenuation, that for some soils may only be achievable with specialized window functions, (3) the impulse response of the soil itself places a practical limit on the usable bandwidth of the radar, and (4) dynamic ranges and sensitivities will need to be orders of magnitude greater than typical surface-imaging SARs, leading to significant impact on SAR parameters, for example compressing the usable range of pulse repetition frequencies (PRFs).

  5. 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.

  6. Mathematical analysis study for radar data processing and enhancement. Part 1: Radar data analysis

    NASA Technical Reports Server (NTRS)

    James, R.; Brownlow, J. D.

    1985-01-01

    A study is performed under NASA contract to evaluate data from an AN/FPS-16 radar installed for support of flight programs at Dryden Flight Research Facility of NASA Ames Research Center. The purpose of this study is to provide information necessary for improving post-flight data reduction and knowledge of accuracy of derived radar quantities. Tracking data from six flights are analyzed. Noise and bias errors in raw tracking data are determined for each of the flights. A discussion of an altiude bias error during all of the tracking missions is included. This bias error is defined by utilizing pressure altitude measurements made during survey flights. Four separate filtering methods, representative of the most widely used optimal estimation techniques for enhancement of radar tracking data, are analyzed for suitability in processing both real-time and post-mission data. Additional information regarding the radar and its measurements, including typical noise and bias errors in the range and angle measurements, is also presented. This is in two parts. This is part 1, an analysis of radar data.

  7. Space Radar Image of Kliuchevskoi Volcano,Russia

    NASA Technical Reports Server (NTRS)

    1994-01-01

    This photograph of the eruption of Kliuchevskoi volcano, Kamchatka, Russia was taken by space shuttle Endeavour astronauts during the early hours of the eruption on September 30, 1994. The ash plume, which reached heights of more than 18 kilometers (50,000 feet), is emerging from a vent on the north flank of Kliuchevskoi, partially hidden by the plume and its shadow in this view. The photograph is oriented with north toward the bottom, for comparison with the Spaceborne Imaging Radar C/X-Band Synthetic Aperture Radar (SIR-C/X-SAR) image (P-44823) that was acquired a few days later. Near the center of the photo, a small whitish steam plume may be seen emanating from the growing lava dome of a companion volcano, Bezymianny.

  8. Shuttle radar images for geologic mapping in tropical rainforest

    NASA Technical Reports Server (NTRS)

    Ford, J. P.; Da Cunha, R.

    1986-01-01

    Images of forested low-relief terrain in the Amazon basin of Brazil, obtained with airborne imaging radar in the Radambrasil project, are compared with SIR-A and Landsat MSS band-7 images to evaluate their usefulness in constructing geologic maps. Sample images are shown, and it is found that Radam images are more useful in distinguishing drainage patterns and mapping the region distribution of stream channels due to their relatively low depression angles (less than 25 deg as opposed to 43-37 deg for SIR-A), but that SIR-A images give superior discrimination of alluvial forest, where trees stand in water, due to the higher reflectivity of branches and water at the SIR-A wavelength (23.5 cm as opposed to 3 cm for Radam). Alluvial forest is also identified by Landsat band 7.

  9. Synthetic aperture radar/LANDSAT MSS image registration

    NASA Technical Reports Server (NTRS)

    Maurer, H. E. (editor); Oberholtzer, J. D. (editor); Anuta, P. E. (editor)

    1979-01-01

    Algorithms and procedures necessary to merge aircraft synthetic aperture radar (SAR) and LANDSAT multispectral scanner (MSS) imagery were determined. The design of a SAR/LANDSAT data merging system was developed. Aircraft SAR images were registered to the corresponding LANDSAT MSS scenes and were the subject of experimental investigations. Results indicate that the registration of SAR imagery with LANDSAT MSS imagery is feasible from a technical viewpoint, and useful from an information-content viewpoint.

  10. Space Radar Image of Salt Lake City, Utah

    NASA Technical Reports Server (NTRS)

    1994-01-01

    This radar image of Salt Lake City, Utah, illustrates the different land use patterns that are present in the Utah Valley. Salt Lake City lies between the shores of the Great Salt Lake (the dark area on the left side of the image) and the Wasatch Front Range (the mountains in the upper half of the image). The Salt Lake City area is of great interest to urban planners because of the combination of lake, valley and alpine environments that coexist in the region. Much of the southern shore of the Great Salt Lake is a waterfowl management area. The green grid pattern in the right center of the image is Salt Lake City and its surrounding communities. The Salt Lake City airport is visible as the brown rectangle near the center of the image. Interstate Highway 15 runs from the middle right edge to the upper left of the image. The bright white patch east of Interstate 15 is the downtown area, including Temple Square and the state capitol. The University of Utah campus is the yellowish area that lies at the base of the mountains, east of Temple Square. The large reservoir in the lower left center is a mine tailings pond. The semi-circular feature in the mountains at the bottom edge of the image is the Kennecott Copper Mine. The area shown is 60 kilometers by 40 kilometers (37 miles by 25 miles) and is centered at 40.6 degrees north latitude, 112.0 degrees west longitude. North is toward the upper left. 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 April 10, 1994. The colors in this image represent the following radar channels and polarizations: red is L-band, horizontally transmitted and received; green is L-band, horizontally transmitted and vertically received; and blue is C-band, horizontally transmitted and vertically 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 program.

  11. Knowledge-based signal processing for radar ESM systems

    NASA Astrophysics Data System (ADS)

    Roe, J.; Cussons, S.; Feltham, A.

    1990-10-01

    Radar electronic support measures (ESM) systems perform the functions of threat detection and area surveillance to determine the identity and bearing of surrounding radar emitters. Automatic ESM systems incorporate a passive receiver to measure the parameters of detected radar pulses and an automatic processor to rapidly sort pulses and identify the emitters. Current processors use algorithmic processing methods which are inflexible and do not fully utilize available sources of a priori information. The paper discusses the role of knowledge-based processing methods and how they may be applied to the key ESM signal-processing functions of deinterleaving, merge and emitter identification. ESM processors are required to sort input pulse data streams exceeding one million pulses per second and minimize the reporting latency of new emitters. The paper further discusses the requirements to achieve real-time operation of knowledge-based ESM processing techniques.

  12. High Resolution 3D Radar Imaging of Comet Interiors

    NASA Astrophysics Data System (ADS)

    Asphaug, E. I.; Gim, Y.; Belton, M.; Brophy, J.; Weissman, P. R.; Heggy, E.

    2012-12-01

    Knowing the interiors of comets and other primitive bodies is fundamental to our understanding of how planets formed. We have developed a Discovery-class mission formulation, Comet Radar Explorer (CORE), based on the use of previously flown planetary radar sounding techniques, with the goal of obtaining high resolution 3D images of the interior of a small primitive body. We focus on the Jupiter-Family Comets (JFCs) as these are among the most primitive bodies reachable by spacecraft. Scattered in from far beyond Neptune, they are ultimate targets of a cryogenic sample return mission according to the Decadal Survey. Other suitable targets include primitive NEOs, Main Belt Comets, and Jupiter Trojans. The approach is optimal for small icy bodies ~3-20 km diameter with spin periods faster than about 12 hours, since (a) navigation is relatively easy, (b) radar penetration is global for decameter wavelengths, and (c) repeated overlapping ground tracks are obtained. The science mission can be as short as ~1 month for a fast-rotating JFC. Bodies smaller than ~1 km can be globally imaged, but the navigation solutions are less accurate and the relative resolution is coarse. Larger comets are more interesting, but radar signal is unlikely to be reflected from depths greater than ~10 km. So, JFCs are excellent targets for a variety of reasons. We furthermore focus on the use of Solar Electric Propulsion (SEP) to rendezvous shortly after the comet's perihelion. This approach leaves us with ample power for science operations under dormant conditions beyond ~2-3 AU. This leads to a natural mission approach of distant observation, followed by closer inspection, terminated by a dedicated radar mapping orbit. Radar reflections are obtained from a polar orbit about the icy nucleus, which spins underneath. Echoes are obtained from a sounder operating at dual frequencies 5 and 15 MHz, with 1 and 10 MHz bandwidths respectively. The dense network of echoes is used to obtain global 3D images of interior structure to ~20 m, and to map dielectric properties (related to internal composition) to better than 200 m throughout. This is comparable in detail to modern 3D medical ultrasound, although we emphasize that the techniques are somewhat different. An interior mass distribution is obtained through spacecraft tracking, using data acquired during the close, quiet radar orbits. This is aligned with the radar-based images of the interior, and the shape model, to contribute to the multi-dimensional 3D global view. High-resolution visible imaging provides boundary conditions and geologic context to these interior views. An infrared spectroscopy and imaging campaign upon arrival reveals the time-evolving activity of the nucleus and the structure and composition of the inner coma, and the definition of surface units. CORE is designed to obtain a total view of a comet, from the coma to the active and evolving surface to the deep interior. Its primary science goal is to obtain clear images of internal structure and dielectric composition. These will reveal how the comet was formed, what it is made of, and how it 'works'. By making global yet detailed connections from interior to exterior, this knowledge will be an important complement to the Rosetta mission, and will lay the foundation for comet nucleus sample return by revealing the areas of shallow depth to 'bedrock', and relating accessible deposits to their originating provenances within the nucleus.

  13. Noise resistant algorithm for radar images recognition and classification

    NASA Astrophysics Data System (ADS)

    Zeljkovi?, Vesna; Li, Qiang; Vincelette, Robert; Tameze, Claude; Liu, Fengshan

    2009-08-01

    We propose a novel algorithm for automatic aircraft classification. The proposed method makes numerical equivalents to shape, size and other aircraft features as critical criteria to constitute the algorithm for their correct classification. This method uses Inverse Synthetic Aperture Radar (ISAR) aircraft images that are making maneuvers that introduce aircraft rotation relative to the radar station. By means of analyzing the shape of the radar pulse and Doppler shifts that are caused by rotation of the aircraft, an image of the aircraft shape can be constructed. We computer simulated five different categories of ISAR images. We tested the proposed classification algorithm on these five categories and on two more categories taken from the Internet. One aircraft model is simulated and the other one is a real sequence with much added noise. All seven different aircraft models are flying a holding pattern. We investigated where in the holding patterns ISAR reflections made it possible to identify each category of aircraft. Our experimental results demonstrate that in most parts of the holding pattern the category of the aircraft can be successfully identified. The performed tests show that the proposed algorithm appears to be noise resistant.

  14. Forest discrimination with multipolarization imaging radar

    NASA Technical Reports Server (NTRS)

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

    1985-01-01

    The relations between polarization signatures and biophysical characteristics through a range of different forest environments were investigated using airborne synthetic-aperture (SAR) images acquired at L-band on March 1, 1984 in South Carolina. SAR data acquired in four linear polarization states with 10-m spatial resolution were encoded as color composite images and compared to US Forest Service forest stand data. The most useful correlative forest data were stand basal area, forest age, site condition index, and forest management type. It is found that the multipolarization images discriminate variation in tree density or difference in the amount of understory, but no evidence has been found for discrimination between evergreen and deciduous forest types.

  15. Radar Image with Color as Height, Old Khmer Road, Cambodia

    NASA Technical Reports Server (NTRS)

    2002-01-01

    This image shows the Old Khmer Road (Inrdratataka-Bakheng causeway) in Cambodia extending from the 9th Century A.D. capitol city of Hariharalaya in the lower right portion of the image to the later 10th Century AD capital of Yasodharapura. This was located in the vicinity of Phnom Bakheng (not shown in image). The Old Road is believed to be more than 1000 years old. Its precise role and destination within the 'new' city at Angkor is still being studied by archeologists. But wherever it ended, it not only offered an immense processional way for the King to move between old and new capitols, it also linked the two areas, widening the territorial base of the Khmer King. Finally, in the past and today, the Old Road managed the waters of the floodplain. It acted as a long barrage or dam for not only the natural streams of the area but also for the changes brought to the local hydrology by Khmer population growth.

    The image was acquired by NASA's Airborne Synthetic Aperture Radar (AIRSAR). Image brightness is from the P-band (68 cm wavelength) radar backscatter, which is a measure of how much energy the surface reflects back towards the radar. Color is used to represent elevation contours. One cycle of color represents 20 m of elevation change, that is going from blue to red to yellow to green and back to blue again corresponds to 20 m of elevation change. Image dimensions are approximately 3.4 km by 3.5 km with a pixel spacing of 5 m. North is at top.

    AIRSAR flies aboard a NASA DC-8 based at NASA's Dryden Flight Research Center, Edwards, Calif. In the TOPSAR mode, AIRSAR collects radar interferometry data from two spatially separated antennas (2.6 meters, or 8.5 feet). Information from the two antennas is used to form radar backscatter imagery and to generate highly accurate elevation data. Built, operated and managed by JPL, AIRSAR is part of NASA's Earth Science Enterprise program. JPL is a division of the California Institute of Technology in Pasadena.

  16. Space Radar Image of Karakax Valley, China 3-D

    NASA Technical Reports Server (NTRS)

    1994-01-01

    This three-dimensional perspective of the remote Karakax Valley in the northern Tibetan Plateau of western China was created by combining two spaceborne radar images using a technique known as interferometry. Visualizations like this are helpful to scientists because they reveal where the slopes of the valley are cut by erosion, as well as the accumulations of gravel deposits at the base of the mountains. These gravel deposits, called alluvial fans, are a common landform in desert regions that scientists are mapping in order to learn more about Earth's past climate changes. Higher up the valley side is a clear break in the slope, running straight, just below the ridge line. This is the trace of the Altyn Tagh fault, which is much longer than California's San Andreas fault. Geophysicists are studying this fault for clues it may be able to give them about large faults. Elevations range from 4000 m (13,100 ft) in the valley to over 6000 m (19,700 ft) at the peaks of the glaciated Kun Lun mountains running from the front right towards the back. Scale varies in this perspective view, but the area is about 20 km (12 miles) wide in the middle of the image, and there is no vertical exaggeration. The two radar images were acquired on separate days during the second flight of the Spaceborne Imaging Radar-C/X-band Synthetic Aperture Radar (SIR-C/X-SAR) aboard the space shuttle Endeavour in October 1994. The interferometry technique provides elevation measurements of all points in the scene. The resulting digital topographic map was used to create this view, looking northwest from high over the valley. Variations in the colors can be related to gravel, sand and rock outcrops. This image is centered at 36.1 degrees north latitude, 79.2 degrees east longitude. 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 the average of L-band vertically transmitted, vertically received and C-band vertically transmitted, vertically received; and blue is C-band vertically transmitted, vertically 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.

  17. Space Radar Image of Mount Pinatubo Volcano, Philippines

    NASA Technical Reports Server (NTRS)

    1994-01-01

    These are color composite radar images showing the area around Mount Pinatubo in the Philippines. The images were acquired by the Spaceborne Imaging Radar-C and X-band Synthetic Aperture Radar (SIR-C/X-SAR) aboard the space shuttle Endeavour on April 14, 1994 (left image) and October 5,1994 (right image). The images are centered at about 15 degrees north latitude and 120.5 degrees east longitude. Both images were obtained with the same viewing geometry. The color composites were made by displaying the L-band (horizontally transmitted and received) in red; the L-band (horizontally transmitted and vertically received) in green; and the C-band (horizontally transmitted and vertically received) in blue. The area shown is approximately 40 kilometers by 65 kilometers (25 miles by 40 miles). The main volcanic crater on Mount Pinatubo produced by the June 1991 eruptions and the steep slopes on the upper flanks of the volcano are easily seen in these images. Red on the high slopes shows the distribution of the ash deposited during the 1991 eruption, which appears red because of the low cross-polarized radar returns at C and L bands. The dark drainages radiating away from the summit are the smooth mudflows, which even three years after the eruptions continue to flood the river valleys after heavy rain. Comparing the two images shows that significant changes have occurred in the intervening five months along the Pasig-Potrero rivers (the dark area in the lower right of the images). Mudflows, called 'lahars,' that occurred during the 1994 monsoon season filled the river valleys, allowing the lahars to spread over the surrounding countryside. Three weeks before the second image was obtained, devastating lahars more than doubled the area affected in the Pasig-Potrero rivers, which is clearly visible as the increase in dark area on the lower right of the images. Migration of deposition to the east (right) has affected many communities. Newly affected areas included the community of Bacolor, Pampanga, where thousands of homes were buried in meters of hot mud and rock as 80,000 people fled the lahar-stricken area. Scientists are closely monitoring the westward migration ( toward the left in this image) of the lahars as the Pasig-Potrero rivers seek to join with the Porac River, an area that has not seen laharic activity since the eruption. This could be devastating because the Pasig-Potrero rivers might be permanently redirected to lower elevations along the Porac River where communities are located. Ground saturation with water during the rainy season reveals inactive channels that were dry in the April image. A small lake has turned into a pond in the lower reaches of the Potrero River because the channels are full of lahar deposits and the surface runoff has no where to flow. Changes in the degree of erosion in ash and pumice deposits from the 1991 eruption can also be seen in the channels that deliver the mudflow material to the Pasig-Potrero rivers. The 1991 Mount Pinatubo eruption is well known for its near-global effects on the atmosphere and short-term climate due to the large amount of sulfur dioxide that was injected into the upper atmosphere. Locally, however, the effects will most likely continue to impact surrounding areas for as long as the next 10 to 15 years. Mudflows, quite certainly, will continue to pose severe hazards to adjacent areas. Radar observations like those obtained by SIR-C/X-SAR will play a key role in monitoring these changes because of the radar's ability to see in daylight or darkness and even in the worst weather conditions. Radar imaging will be particularly useful, for example, during the monsoon season, when the lahars form. Frequent imaging of these lahar fields will allow scientists to better predict when they are likely to begin flowing again and which communities might be at risk. 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

  18. Space Radar Image of the Silk route in Niya, Taklamak, China

    NASA Technical Reports Server (NTRS)

    1999-01-01

    This composite image is of an area thought to contain the ruins of the ancient settlement of Niya. It is located in the southwest corner of the Taklamakan Desert in China's Sinjiang Province. This region was part of some of China's earliest dynasties and from the third century BC on was traversed by the famous Silk Road. The Silk Road, passing east-west through this image, was an ancient trade route that led across Central Asia's desert to Persia, Byzantium and Rome. The multi-frequency, multi-polarized radar imagery was acquired on orbit 106 of the space shuttle Endeavour on April 16, 1994 by the Spaceborne Imaging Radar-C/X-band Synthetic Aperture Radar. The image is centered at 37.78 degrees north latitude and 82.41 degrees east longitude. The area shown is approximately 35 kilometers by 83 kilometers (22 miles by 51 miles). The image is a composite of an image from an Earth-orbiting satellite called Systeme Probatoire d'Observation de la Terre (SPOT)and a SIR-C multi-frequency, multi-polarized radar image. The false-color radar image was created by displaying the C-band (horizontally transmitted and received) return in red, the L-band (horizontally transmitted and received) return in green, and the L-band (horizontally transmitted and vertically received) return in blue. The prominent east/west pink formation at the bottom of the image is most likely a ridge of loosely consolidated sedimentary rock. The Niya River -- the black feature in the lower right of the French satellite image -- meanders north-northeast until it clears the sedimentary ridge, at which point it abruptly turns northwest. Sediment and evaporite deposits left by the river over millennia dominate the center and upper right of the radar image (in light pink). High ground, ridges and dunes are seen among the riverbed meanderings as mottled blue. Through image enhancement and analysis, a new feature probably representing a man-made canal has been discovered and mapped. 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: the 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.

  19. Image Processing

    NASA Technical Reports Server (NTRS)

    1987-01-01

    A new spinoff product was derived from Geospectra Corporation's expertise in processing LANDSAT data in a software package. Called ATOM (for Automatic Topographic Mapping), it's capable of digitally extracting elevation information from stereo photos taken by spaceborne cameras. ATOM offers a new dimension of realism in applications involving terrain simulations, producing extremely precise maps of an area's elevations at a lower cost than traditional methods. ATOM has a number of applications involving defense training simulations and offers utility in architecture, urban planning, forestry, petroleum and mineral exploration.

  20. Radar Image with Color as Height, Sman Teng, Temple, Cambodia

    NASA Technical Reports Server (NTRS)

    2002-01-01

    This image of Cambodia's Angkor region, taken by NASA's Airborne Synthetic Aperture Radar (AIRSAR), reveals a temple (upper-right) not depicted on early 19th Century French archeological survey maps and American topographic maps. The temple, known as 'Sman Teng,' was known to the local Khmer people, but had remained unknown to historians due to the remoteness of its location. The temple is thought to date to the 11th Century: the heyday of Angkor. It is an important indicator of the strategic and natural resource contributions of the area northwest of the capitol, to the urban center of Angkor. Sman Teng, the name designating one of the many types of rice enjoyed by the Khmer, was 'discovered' by a scientist at NASA's Jet Propulsion Laboratory, Pasadena, Calif., working in collaboration with an archaeological expert on the Angkor region. Analysis of this remote area was a true collaboration of archaeology and technology. Locating the temple of Sman Teng required the skills of scientists trained to spot the types of topographic anomalies that only radar can reveal.

    This image, with a pixel spacing of 5 meters (16.4 feet), depicts an area of approximately 5 by 4.7 kilometers (3.1 by 2.9 miles). North is at top. Image brightness is from the P-band (68 centimeters, or 26.8 inches) wavelength radar backscatter, a measure of how much energy the surface reflects back toward the radar. Color is used to represent elevation contours. One cycle of color represents 25 meters (82 feet) of elevation change, so going from blue to red to yellow to green and back to blue again corresponds to 25 meters (82 feet) of elevation change.

    AIRSAR flies aboard a NASA DC-8 based at NASA's Dryden Flight Research Center, Edwards, Calif. In the TOPSAR mode, AIRSAR collects radar interferometry data from two spatially separated antennas (2.6 meters, or 8.5 feet). Information from the two antennas is used to form radar backscatter imagery and to generate highly accurate elevation data. Built, operated and managed by JPL, AIRSAR is part of NASA's Earth Science Enterprise program. JPL is a division of the California Institute of Technology in Pasadena.

  1. Evidence for crater ejecta on Venus tessera terrain from Earth-based radar images

    NASA Astrophysics Data System (ADS)

    Campbell, Bruce A.; Campbell, Donald B.; Morgan, Gareth A.; Carter, Lynn M.; Nolan, Michael C.; Chandler, John F.

    2015-04-01

    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.

  2. Abstract--Post processing reconstruction and resolution enhancement algorithms can be applied to Cassini Titan Radar

    E-print Network

    Long, David G.

    to Cassini Titan Radar Mapper data to improve the image resolution for scatterometer- mode imagery to Cassini Radar data. Some sample results are provided. A comparison with the Backus-Gilbert algorithm is also provided. I. INTRODUCTION HE Cassini mission to Saturn includes a radar sensor to image

  3. Holographic Radar Imaging Privacy Techniques Utilizing Dual-Frequency Implementation

    SciTech Connect

    McMakin, Douglas L.; Hall, Thomas E.; Sheen, David M.

    2008-04-18

    Over the last 15 years, the Pacific Northwest National Laboratory has performed significant research and development activities to enhance the state of the art of holographic radar imaging systems to be used at security checkpoints for screening people for concealed threats hidden under their garments. These enhancement activities included improvements to privacy techniques to remove human features and providing automatic detection of body-worn concealed threats. The enhanced privacy and detection methods used both physical and software imaging techniques. The physical imaging techniques included polarization-diversity illumination and reception, dual-frequency implementation, and high-frequency imaging at 60 GHz. Software imaging techniques to enhance the privacy of the person under surveillance included extracting concealed threat artifacts from the imagery to automatically detect the threat. This paper will focus on physical privacy techniques using dual-frequency implementation.

  4. Synthetic aperture radar images with composite azimuth resolution

    DOEpatents

    Bielek, Timothy P; Bickel, Douglas L

    2015-03-31

    A synthetic aperture radar (SAR) image is produced by using all phase histories of a set of phase histories to produce a first pixel array having a first azimuth resolution, and using less than all phase histories of the set to produce a second pixel array having a second azimuth resolution that is coarser than the first azimuth resolution. The first and second pixel arrays are combined to produce a third pixel array defining a desired SAR image that shows distinct shadows of moving objects while preserving detail in stationary background clutter.

  5. Standoff concealed weapon detection using a 350-GHz radar imaging system

    NASA Astrophysics Data System (ADS)

    Sheen, David M.; Hall, Thomas E.; Severtsen, Ronald H.; McMakin, Douglas L.; Hatchell, Brian K.; Valdez, Patrick L. J.

    2010-04-01

    The sub-millimeter (sub-mm) wave frequency band from 300 - 1000 GHz is currently being developed for standoff concealed weapon detection imaging applications. This frequency band is of interest due to the unique combination of high resolution and clothing penetration. The Pacific Northwest National Laboratory (PNNL) is currently developing a 350 GHz, active, wideband, three-dimensional, radar imaging system to evaluate the feasibility of active sub-mm imaging for standoff detection. Standoff concealed weapon and explosive detection is a pressing national and international need for both civilian and military security, as it may allow screening at safer distances than portal screening techniques. PNNL has developed a prototype active wideband 350 GHz radar imaging system based on a wideband, heterodyne, frequency-multiplier-based transceiver system coupled to a quasi-optical focusing system and high-speed rotating conical scanner. This prototype system operates at ranges up to 10+ meters, and can acquire an image in 10 - 20 seconds, which is fast enough to scan cooperative personnel for concealed weapons. The wideband operation of this system provides accurate ranging information, and the images obtained are fully three-dimensional. During the past year, several improvements to the system have been designed and implemented, including increased imaging speed using improved balancing techniques, wider bandwidth, and improved image processing techniques. In this paper, the imaging system is described in detail and numerous imaging results are presented.

  6. Radar remote sensing of wind-driven land degradation processes in northeastern Patagonia.

    PubMed

    del Valle, H F; Blanco, P D; Metternicht, G I; Zinck, J A

    2010-01-01

    Wind-driven land degradation negatively impacts on rangeland production and infrastructure in the Valdes Peninsula, northeastern Patagonia. The Valdes Peninsula has the most noticeable dunefields of the Patagonian drylands. Wind erosion has been assessed at different scales in this region, but often with limited data. In general, terrain features caused by wind activity are better discriminated by active microwaves than by sensors operating in the visible and infrared regions of the electromagnetic spectrum. This paper aims to analyze wind-driven land degradation processes that control the radar backscatter observed in different sources of radar imagery. We used subsets derived from SIR-C, ERS-1 and 2, ENVISAT ASAR, RADARSAT-1, and ALOS PALSAR data. The visibility of aeolian features on radar images is mostly a function of wavelength, polarization, and incidence angle. Stabilized sand deposits are clearly observed in radar images, with defined edges but also signals of ongoing wind erosion. One of the most conspicuous features corresponds to old track sand dunes, a mixture of active and inactive barchanoid ridges and parabolic dunes. This is a clear example of deactivation of migrating dunes under the influence of vegetation. The L-band data reveal details of these sand ridges, whereas the C-band data only allow detecting a few of the larger tracks. The results of this study enable us to make recommendations about the utility of some radar sensor configurations for wind-driven land degradation reconnaissance in mid-latitude regions. PMID:20048294

  7. Optimum frequency for subsurface-imaging synthetic-aperture radar

    SciTech Connect

    Brock, B.C.; Patitz, W.E.

    1993-05-01

    A subsurface-imaging synthetic-aperture radar (SISAR) has potential for application in areas as diverse as non-proliferation programs for nuclear weapons to environmental monitoring. However, most conventional synthetic-aperture radars operate at higher microwave frequencies which do not significantly penetrate below the soil surface. This study attempts to provide a basis for determining optimum frequencies and frequency ranges which will allow synthetic-aperture imaging of buried targets. Since the radar return from a buried object must compete with the return from surface clutter, the signal-to-clutter ratio is an appropriate measure of performance for a SISAR. A parameter-based modeling approach is used to model the complex dielectric constant of the soil from measured data obtained from the literature. Theoretical random-surface scattering models, based on statistical solutions to Maxwell`s equations, are used to model the clutter. These models are combined to estimate the signal-to-clutter ratio for canonical targets buried in several soil configurations. Initial results indicate that the HF spectrum (3--30 MHz), although it could be used to detect certain targets under some conditions, has limited practical value for use with SISAR, while the upper vhf through uhf spectrum ({approximately}100 MHz--1 GHz) shows the most promise for a general purpose SISAR system. Recommendations are included for additional research.

  8. Optimum frequency for subsurface-imaging synthetic-aperture radar

    SciTech Connect

    Brock, B.C.; Patitz, W.E.

    1993-05-01

    A subsurface-imaging synthetic-aperture radar (SISAR) has potential for application in areas as diverse as non-proliferation programs for nuclear weapons to environmental monitoring. However, most conventional synthetic-aperture radars operate at higher microwave frequencies which do not significantly penetrate below the soil surface. This study attempts to provide a basis for determining optimum frequencies and frequency ranges which will allow synthetic-aperture imaging of buried targets. Since the radar return from a buried object must compete with the return from surface clutter, the signal-to-clutter ratio is an appropriate measure of performance for a SISAR. A parameter-based modeling approach is used to model the complex dielectric constant of the soil from measured data obtained from the literature. Theoretical random-surface scattering models, based on statistical solutions to Maxwell's equations, are used to model the clutter. These models are combined to estimate the signal-to-clutter ratio for canonical targets buried in several soil configurations. Initial results indicate that the HF spectrum (3--30 MHz), although it could be used to detect certain targets under some conditions, has limited practical value for use with SISAR, while the upper vhf through uhf spectrum ([approximately]100 MHz--1 GHz) shows the most promise for a general purpose SISAR system. Recommendations are included for additional research.

  9. 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.

  10. An Ultra-Wideband Radar System for Through-the-Wall Imaging using a Mobile Robot

    E-print Network

    , rescue missions in collapsed buildings, and target feature extraction. While narrowband Doppler radar Doppler radar in the millimeter- wave or infrared spectrum has been shown to provide good resolution to Doppler radar for through-the-wall imaging: UWB compensates for the significant drop in center frequency

  11. DETECTING AND TRACKING SEVERE STORMS IN 3D DOPPLER RADAR IMAGES

    E-print Network

    Barron, John

    DETECTING AND TRACKING SEVERE STORMS IN 3D DOPPLER RADAR IMAGES Robert E. Mercer, John L. Barron in Doppler radar datasets. This 3D detection and tracking algorithm is posed in a relaxation labelling, N6A 5B7 Paul Joe Paul.Joe@ec.gc.ca King City Radar Station Meteorological Service of Canada Toronto

  12. A three-dimensional imaging technique for a directional borehole radar

    E-print Network

    van Vliet, Lucas J.

    A three-dimensional imaging technique for a directional borehole radar Koen W.A. van Dongen, Peter M. van den Berg and Jacob T. Fokkema T&A RADAR, Badhuisweg 3, PO Box 37060, 1030 AB Amsterdam, The Netherlands ABSTRACT In this paper we describe a directional borehole radar system. We first present

  13. Improved Speed and Functionality of a 580-GHz Imaging Radar

    NASA Technical Reports Server (NTRS)

    Dengler, Robert; Cooper, Ken; Chattopadhyay, Goutam; Siegel, Peter; Schlecht, Erich; Mehdi, Imran; Skalare, Anders; Gill, John

    2010-01-01

    With this high-resolution imaging radar system, coherent illumination in the 576-to-589-GHz range and phase-sensitive detection are implemented in an all-solid-state design based on Schottky diode sensors and sources. By employing the frequency-modulated, continuous-wave (FMCW) radar technique, centimeter-scale range resolution has been achieved while using fractional bandwidths of less than 3 percent. The high operating frequencies also permit centimeter-scale cross-range resolution at several-meter standoff distances without large apertures. Scanning of a single-pixel transceiver enables targets to be rapidly mapped in three dimensions, so that the technology can be applied to the detection of concealed objects on persons.

  14. Impulse radar imaging system for concealed object detection

    NASA Astrophysics Data System (ADS)

    Podd, F. J. W.; David, M.; Iqbal, G.; Hussain, F.; Morris, D.; Osakue, E.; Yeow, Y.; Zahir, S.; Armitage, D. W.; Peyton, A. J.

    2013-10-01

    Electromagnetic systems for imaging concealed objects at checkpoints typically employ radiation at millimetre and terahertz frequencies. These systems have been shown to be effective and provide a sufficiently high resolution image. However there are difficulties and current electromagnetic systems have limitations particularly in accurately differentiating between threat and innocuous objects based on shape, surface emissivity or reflectivity, which are indicative parameters. In addition, water has a high absorption coefficient at millimetre wavelength and terahertz frequencies, which makes it more difficult for these frequencies to image through thick damp clothing. This paper considers the potential of using ultra wideband (UWB) in the low gigahertz range. The application of this frequency band to security screening appears to be a relatively new field. The business case for implementing the UWB system has been made financially viable by the recent availability of low-cost integrated circuits operating at these frequencies. Although designed for the communication sector, these devices can perform the required UWB radar measurements as well. This paper reports the implementation of a 2 to 5 GHz bandwidth linear array scanner. The paper describes the design and fabrication of transmitter and receiver antenna arrays whose individual elements are a type of antipodal Vivaldi antenna. The antenna's frequency and angular response were simulated in CST Microwave Studio and compared with laboratory measurements. The data pre-processing methods of background subtraction and deconvolution are implemented to improve the image quality. The background subtraction method uses a reference dataset to remove antenna crosstalk and room reflections from the dataset. The deconvolution method uses a Wiener filter to "sharpen" the returned echoes which improves the resolution of the reconstructed image. The filter uses an impulse response reference dataset and a signal-to-noise parameter to determine how the frequencies contained in the echo dataset are normalised. The chosen image reconstruction algorithm is based on the back-projection method. The algorithm was implemented in MATLAB and uses a pre-calculated sensitivity matrix to increase the computation speed. The results include both 2D and 3D image datasets. The 3D datasets were obtained by scanning the dual sixteen element linear antenna array over the test object. The system has been tested on both humans and mannequin test objects. The front surface of an object placed on the human/mannequin torso is clearly visible, but its presence is also seen from a tell-tale imaging characteristic. This characteristic is caused by a reduction in the wave velocity as the electromagnetic radiation passes through the object, and manifests as an indentation in the reconstructed image that is readily identifiable. The prototype system has been shown to easily detect a 12 mm x 30 mm x70 mm plastic object concealed under clothing.

  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. SUBMITTED TO THE IEEE TRANSACTIONS ON SIGNAL PROCESSING 1 Spatial Diversity in Radars -Models and

    E-print Network

    Blum, Rick

    . It is well known that in conventional radar, slow fluctuations of the target radar cross section (RCS) resultSUBMITTED TO THE IEEE TRANSACTIONS ON SIGNAL PROCESSING 1 Spatial Diversity in Radars - Models-input multiple-output (MIMO) communications, this proposal introduces the statistical MIMO radar concept. To our

  17. Iterative Self-Dual Reconstruction on Radar Image Recovery

    SciTech Connect

    Martins, Charles; Medeiros, Fatima; Ushizima, Daniela; Bezerra, Francisco; Marques, Regis; Mascarenhas, Nelson

    2010-05-21

    Imaging systems as ultrasound, sonar, laser and synthetic aperture radar (SAR) are subjected to speckle noise during image acquisition. Before analyzing these images, it is often necessary to remove the speckle noise using filters. We combine properties of two mathematical morphology filters with speckle statistics to propose a signal-dependent noise filter to multiplicative noise. We describe a multiscale scheme that preserves sharp edges while it smooths homogeneous areas, by combining local statistics with two mathematical morphology filters: the alternating sequential and the self-dual reconstruction algorithms. The experimental results show that the proposed approach is less sensitive to varying window sizes when applied to simulated and real SAR images in comparison with standard filters.

  18. Photoacoustic radar imaging signal-to-noise ratio, contrast, and resolution enhancement using

    E-print Network

    Mandelis, Andreas

    Photoacoustic radar imaging signal-to-noise ratio, contrast, and resolution enhancement using-correlation (radar) frequency-domain photoacoustic (PA) imaging parameters [signal-to-noise ratio (SNR), contrast.5120, 110.5125. Photoacoustic (PA) imaging can be implemented ei- ther in time domain by powerful nanosecond

  19. 47 CFR 15.509 - Technical requirements for ground penetrating radars and wall imaging systems.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 47 Telecommunication 1 2010-10-01 2010-10-01 false Technical requirements for ground penetrating radars and wall imaging systems. 15.509 Section 15.509 Telecommunication FEDERAL COMMUNICATIONS... ground penetrating radars and wall imaging systems. (a) The UWB bandwidth of an imaging system...

  20. 47 CFR 15.509 - Technical requirements for ground penetrating radars and wall imaging systems.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 47 Telecommunication 1 2011-10-01 2011-10-01 false Technical requirements for ground penetrating radars and wall imaging systems. 15.509 Section 15.509 Telecommunication FEDERAL COMMUNICATIONS... ground penetrating radars and wall imaging systems. (a) The UWB bandwidth of an imaging system...

  1. 47 CFR 15.509 - Technical requirements for ground penetrating radars and wall imaging systems.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 47 Telecommunication 1 2013-10-01 2013-10-01 false Technical requirements for ground penetrating radars and wall imaging systems. 15.509 Section 15.509 Telecommunication FEDERAL COMMUNICATIONS... ground penetrating radars and wall imaging systems. (a) The UWB bandwidth of an imaging system...

  2. 47 CFR 15.509 - Technical requirements for ground penetrating radars and wall imaging systems.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 47 Telecommunication 1 2014-10-01 2014-10-01 false Technical requirements for ground penetrating radars and wall imaging systems. 15.509 Section 15.509 Telecommunication FEDERAL COMMUNICATIONS... ground penetrating radars and wall imaging systems. (a) The UWB bandwidth of an imaging system...

  3. 47 CFR 15.509 - Technical requirements for ground penetrating radars and wall imaging systems.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 47 Telecommunication 1 2012-10-01 2012-10-01 false Technical requirements for ground penetrating radars and wall imaging systems. 15.509 Section 15.509 Telecommunication FEDERAL COMMUNICATIONS... ground penetrating radars and wall imaging systems. (a) The UWB bandwidth of an imaging system...

  4. 3D Synthetic Aperture Radar Imaging of the Interior of the Cometary Nucleus

    NASA Astrophysics Data System (ADS)

    Gim, Y.; Heggy, E.; Arumugam, D.; Wu, X.; Asphaug, E. I.

    2014-12-01

    A capability of constructing the primitive body's interior structure such as the cometary nucleus is the key to the successful realization of a future three-dimensional (3D) mapping mission using a long-wavelength (20-60 meters) penetrating radar system. Discontinuities in the material density and/or composition at the surface and deep interior reflect a small amount of incoming electro-magnetic waves back to the orbiting radar system that records amplitudes and travel times (or phases). By coherently processing the phase information collected from different viewing angles at different times, we would like to show that we could build 3D internal structural and compositional images, and thereby provide crucial information about the origin and evolution of the cometary nucleus. Here, we will report our efforts on the high-fidelity electromagnetic (E&M) forward modeling, comet modeling related to Rosetta experiments, and validation of a radar reflection tomographic imaging technique. We have developed innovative techniques to reduce numerical errors in the E&M modeling, allowing us to simulate data collection in a realistic environment while significantly reducing spurious effects caused by numerical errors or imperfect matching layers surrounding the simulation scene. For comet modeling, we have used models developed for radar sounding experiments on Rosetta comet 67P/Churyumov-Gerasimenko. These models are driven from various scientific hypothesis and lab measurements of cometary materials. For an imaging algorithm, we have used a proven SAR technique after taking into account the slowness of light inside the comet and refraction (ray-bending) at the comet surface. We have successfully imaged 2D cross-sectional images of various comet models and will pursuit 3D simulation and imaging reconstruction in the near future.

  5. Experiment in Onboard Synthetic Aperture Radar Data Processing

    NASA Technical Reports Server (NTRS)

    Holland, Matthew

    2011-01-01

    Single event upsets (SEUs) are a threat to any computing system running on hardware that has not been physically radiation hardened. In addition to mandating the use of performance-limited, hardened heritage equipment, prior techniques for dealing with the SEU problem often involved hardware-based error detection and correction (EDAC). With limited computing resources, software- based EDAC, or any more elaborate recovery methods, were often not feasible. Synthetic aperture radars (SARs), when operated in the space environment, are interesting due to their relevance to NASAs objectives, but problematic in the sense of producing prodigious amounts of raw data. Prior implementations of the SAR data processing algorithm have been too slow, too computationally intensive, and require too much application memory for onboard execution to be a realistic option when using the type of heritage processing technology described above. This standard C-language implementation of SAR data processing is distributed over many cores of a Tilera Multicore Processor, and employs novel Radiation Hardening by Software (RHBS) techniques designed to protect the component processes (one per core) and their shared application memory from the sort of SEUs expected in the space environment. The source code includes calls to Tilera APIs, and a specialized Tilera compiler is required to produce a Tilera executable. The compiled application reads input data describing the position and orientation of a radar platform, as well as its radar-burst data, over time and writes out processed data in a form that is useful for analysis of the radar observations.

  6. A study on aspect sensitivity of clear-air turbulence using coherent radar imaging of VHF atmospheric radar

    NASA Astrophysics Data System (ADS)

    Chen, J.-S.; Furumoto, J.

    2012-11-01

    Aspect sensitivity of clear-air turbulence was examined with multiple-receiver coherent radar imaging (CRI) of VHF atmospheric radar. The study was carried out by means of aspect angle, estimated from two CRI parameters: direction of arrival of echo center from oblique radar beam and brightness distribution width from vertical radar beam. The brightness distribution was retrieved by the Capon method. Modification of brightness value has been made with a suitable radar beam-weighting function before estimating the two CRI parameters. The radar beam-weighting function used for correction is a Gaussian form, and its standard deviation (beam width) varies with off-beam direction angle and is also adaptive to signal-to-noise ratio of echoes. The use of adaptable beam width can avoid over-modifying the brightness values at the edges of the imaged map, yielding a more reliable estimate of aspect angle. The CRI-estimated aspect angle was compared with that obtained from comparison of echo powers of different oblique radar beams. The statistical features of aspect angles obtained from the two approaches are consistent.

  7. Space Radar Image of San Rafael Glacier, Chile

    NASA Technical Reports Server (NTRS)

    1994-01-01

    A NASA radar instrument has been successfully used to measure some of the fastest moving and most inaccessible glaciers in the world -- in Chile's huge, remote Patagonia ice fields -- demonstrating a technique that could produce more accurate predictions of glacial response to climate change and corresponding sea level changes. This image, produced with interferometric measurements made by the Spaceborne Imaging Radar-C and X-band Synthetic Aperture Radar (SIR-C/X-SAR) flown on the Space Shuttle last fall, has provided the first detailed measurements of the mass and motion of the San Rafael Glacier. Very few measurements have been made of the Patagonian ice fields, which are the world's largest mid-latitude ice masses and account for more than 60 percent of the Southern Hemisphere's glacial area outside of Antarctica. These features make the area essential for climatologists attempting to understand the response of glaciers on a global scale to changes in climate, but the region's inaccessibility and inhospitable climate have made it nearly impossible for scientists to study its glacial topography, meteorology and changes over time. Currently, topographic data exist for only a few glaciers while no data exist for the vast interior of the ice fields. Velocity has been measured on only five of the more than 100 glaciers, and the data consist of only a few single-point measurements. The interferometry performed by the SIR-C/X-SAR was used to generate both a digital elevation model of the glaciers and a map of their ice motion on a pixel-per-pixel basis at very high resolution for the first time. The data were acquired from nearly the same position in space on October 9, 10 and 11, 1994, at L-band frequency (24-cm wavelength), vertically transmitted and received polarization, as the Space Shuttle Endeavor flew over several Patagonian outlet glaciers of the San Rafael Laguna. The area shown in these two images is 50 kilometers by 30 kilometers (30 miles by 18 miles) in size and is centered at 46.6 degrees south latitude, 73.8 degrees west longitude. North is toward the upper right. The top image is a digital elevation model of the scene, where color and saturation represent terrain height (between 0 meters and 2,000 meters or up to 6,500 feet) and brightness represents radar backscatter. Low elevations are shown in blue and high elevations are shown in pink. The digital elevation map of the glacier surface has a horizontal resolution of 15 meters (50 feet) and a vertical resolution of 10 meters (30 feet). High-resolution maps like these acquired over several years would allow scientists to calculate directly long-term changes in the mass of the glacier. The bottom image is a map of ice motion parallel to the radar look direction only, which is from the top of the image. Purple indicates ice motion away from the radar at more than 6 centimeters per day; dark blue is ice motion toward or away at less than 6 cm per day; light blue is motion toward the radar of 6 cm to 20 cm (about 2 to 8 inches) per day; green is motion toward the radar of 20 cm to 45 cm (about 8 to 18 inches) per day; yellow is 45 cm to 85 cm (about 18 to 33 inches) per day; orange is 85 cm to 180 cm (about 33 to 71 inches) per day; red is greater than 180 cm (71 inches) per day. The velocity estimates are accurate to within 5 millimeters per day. The largest velocities are recorded on the San Rafael Glacier in agreement with previous work. Other outlet glaciers exhibit ice velocities of less than 1 meter per day. Several kilometers before its terminus, (left of center) the velocity of the San Rafael Glacier exceeds 10 meters (32 feet) per day, and ice motion cannot be estimated from the data. There, a revisit time interval of less than 12 hours would have been necessary to estimate ice motion from interferometry data. The results however demonstrate that the radar interferometry technique permits the monitoring of glacier characteristics unattainable by any other means. Spaceborne Imaging Radar-C and X-Synthetic Aperture Radar (SIR-C/X-SAR) are part of NASA's

  8. Radar Image with Color as Height, Hariharalaya, Cambodia

    NASA Technical Reports Server (NTRS)

    2002-01-01

    Hariharalaya, the ancient 9th Century A.D. capitol of the Khmer in Cambodia, is shown in the upper center portion of this NASA Airborne Synthetic Aperture Radar (AIRSAR) image. The image was acquired during the 1996 PACRIM mission with AIRSAR operating in the TOPSAR mode. At the center of the image is the terraced sandstone temple mountain of the King Indravarman, the Bakong. The smaller enclosed rectangular feature just to the north is Preah Ko. Further to the south are more rectangular features, temples and water reservoirs attributed to other kings in the earlier part of the 9th Century A.D. and maybe even earlier. Just visible at the top on the image is a long linear feature that forms the southern border of the immense water reservoir, at the center of which is the Lolei temple. The city was the first capitol of the Khmer after the 802 A.D. ceremony consecrating the king as 'Devaraja'. This usually translated as 'god who was king' or 'king who was god'. In the next century, the center of power shifted to the northwest, to the area known today as Angkor.

    Thus this early capital is unique both in being the first after the historical 'founding' of the Khmer Empire, and for being inhabited for a relatively short time. Although kings returned from Angkor in the 11th and 12th Centuries A.D. to build the temple known as the Lolei and to construct the tower in the center of Bakong, the city of Hariharalaya remained on the perimeter of royal power. It was revered, however, as part of a longstanding and important custom of ancestral veneration. This manifested itself in a complex set of rituals honoring one's forebears--also ensuring legitimacy for one's claim to the throne. So behind this seemingly simple patterning of rectangles on the radar image lies many layers of history, ritual and meaning for the Khmer people, past and present.

    Image dimensions are approximately 6 by 4.8 kilometers (3.7 by 3 miles) with a pixel spacing of 5 meters (16.4 feet). North is at top. Image brightness is from the C-band (5.6 centimeters, or 2.2 inches wavelength) radar backscatter, which is a measure of how much energy the surface reflects back toward the radar. Color is used to represent elevation contours. One cycle of color--from blue to red to yellow to green and back to blue again--represents 10 meters (32.8 feet) of elevation change.

    AIRSAR flies aboard a NASA DC-8 based at NASA's Dryden Flight Research Center, Edwards, Calif. In the TOPSAR mode, AIRSAR collects radar interferometry data from two spatially separated antennas (2.6 meters, or 8.5 feet). Information from the two antennas is used to form radar backscatter imagery and to generate highly accurate elevation data. Built, operated and managed by JPL, AIRSAR is part of NASA's Earth Science Enterprise program. JPL is a division of the California Institute of Technology in Pasadena.

  9. Near-Field Three-Dimensional Radar Imaging Techniques and Applications

    SciTech Connect

    Sheen, David M.; McMakin, Douglas L.; Hall, Thomas E.

    2010-07-01

    Three dimensional radio frequency imaging techniques have been developed for a variety of near field applications including radar cross-section imaging, concealed weapon detection, ground penetrating radar imaging, through-barrier imaging, and non-destructive evaluation. These methods employ active radar transceivers that operate at various frequency ranges covering a wide range from less than 100 MHz to in excess of 350 GHz with the frequency range customized for each application. Computational wavefront reconstruction imaging techniques have been developed that optimize the resolution and illumination quality of the images. In this paper, rectilinear and cylindrical three-dimensional imaging techniques are described along with several application results.

  10. Near-field three-dimensional radar imaging techniques and applications.

    PubMed

    Sheen, David; McMakin, Douglas; Hall, Thomas

    2010-07-01

    Three-dimensional radio frequency imaging techniques have been developed for a variety of near-field applications, including radar cross-section imaging, concealed weapon detection, ground penetrating radar imaging, through-barrier imaging, and nondestructive evaluation. These methods employ active radar transceivers that operate at various frequency ranges covering a wide range, from less than 100 MHz to in excess of 350 GHz, with the frequency range customized for each application. Computational wavefront reconstruction imaging techniques have been developed that optimize the resolution and illumination quality of the images. In this paper, rectilinear and cylindrical three-dimensional imaging techniques are described along with several application results. PMID:20648125

  11. A frequency domain radar interferometric imaging (FII) technique based on high-resolution methods

    NASA Astrophysics Data System (ADS)

    Luce, H.; Yamamoto, M.; Fukao, S.; Helal, D.; Crochet, M.

    2001-01-01

    In the present work, we propose a frequency-domain interferometric imaging (FII) technique for a better knowledge of the vertical distribution of the atmospheric scatterers detected by MST radars. This is an extension of the dual frequency-domain interferometry (FDI) technique to multiple frequencies. Its objective is to reduce the ambiguity (resulting from the use of only two adjacent frequencies), inherent with the FDI technique. Different methods, commonly used in antenna array processing, are first described within the context of application to the FII technique. These methods are the Fourier-based imaging, the Capon's and the singular value decomposition method used with the MUSIC algorithm. Some preliminary simulations and tests performed on data collected with the middle and upper atmosphere (MU) radar (Shigaraki, Japan) are also presented. This work is a first step in the developments of the FII technique which seems to be very promising.

  12. Radar echo processing with partitioned de-ramp

    DOEpatents

    Dubbert, Dale F.; Tise, Bertice L.

    2013-03-19

    The spurious-free dynamic range of a wideband radar system is increased by apportioning de-ramp processing across analog and digital processing domains. A chirp rate offset is applied between the received waveform and the reference waveform that is used for downconversion to the intermediate frequency (IF) range. The chirp rate offset results in a residual chirp in the IF signal prior to digitization. After digitization, the residual IF chirp is removed with digital signal processing.

  13. Agile beam laser radar using computational imaging for robotic perception

    NASA Astrophysics Data System (ADS)

    Powers, Michael A.; Stann, Barry L.; Giza, Mark M.

    2015-05-01

    This paper introduces a new concept that applies computational imaging techniques to laser radar for robotic perception. We observe that nearly all contemporary laser radars for robotic (i.e., autonomous) applications use pixel basis scanning where there is a one-to-one correspondence between world coordinates and the measurements directly produced by the instrument. In such systems this is accomplished through beam scanning and/or the imaging properties of focal-plane optics. While these pixel-basis measurements yield point clouds suitable for straightforward human interpretation, the purpose of robotic perception is the extraction of meaningful features from a scene, making human interpretability and its attendant constraints mostly unnecessary. The imposing size, weight, power and cost of contemporary systems is problematic, and relief from factors that increase these metrics is important to the practicality of robotic systems. We present a system concept free from pixel basis sampling constraints that promotes efficient and adaptable sensing modes. The cornerstone of our approach is agile and arbitrary beam formation that, when combined with a generalized mathematical framework for imaging, is suited to the particular challenges and opportunities of robotic perception systems. Our hardware concept looks toward future systems with optical device technology closely resembling modern electronically-scanned-array radar that may be years away from practicality. We present the design concept and results from a prototype system constructed and tested in a laboratory environment using a combination of developed hardware and surrogate devices for beam formation. The technological status and prognosis for key components in the system is discussed.

  14. Size estimate of (99942) Apophis based on radar imaging

    NASA Astrophysics Data System (ADS)

    Brozovic, Marina; Benner, Lance; McMichael, Joseph; Pravec, Petr; Scheirich, Petr; Giorgini, Jon; Magri, Chris; Busch, Michael; Jao, Joseph; Lee, Clement; Nolan, Michael; Taylor, Patrick; Howell, Ellen; Slade, Martin

    2015-11-01

    (99942) Apophis is one of the most important near-Earth asteroids ever discovered. It will make a very close Earth approach on Friday, April 13, 2029 when it will pass within only a few Earth radii above Earth's surface. This will be the closest approach by something this large currently known. Apophis approached within 0.1 au in January of 2013, and we organized an extensive radar campaign at Goldstone and Arecibo between December 2012 and March 2013. Our primary objective was to obtain ranging measurements to improve the orbit, characterize its physical properties, and facilitate detection of the Yarkovsky effect leading to estimation of the mass and bulk density. We obtained frequency-only data, and 150 m and 75 m ranging data. The signal-to-noise ratios (SNRs) were strong enough so that coarsely resolved delay-Doppler images revealed aspects of Apophis’ shape. The visible extents varied from ~0.2 km to ~0.4 km and the bandwidths varied from 0.9 Hz to1.4 Hz. The object is clearly elongated, which is consistent with the large lightcurve amplitude of ~0.9 mag reported by Behrend et al. ( http://obswww.unige.ch/~behrend/r099942a.png) and Pravec et al. (Icarus 233, 48-60, 2014). The radar images suggest that Apophis could be a contact binary.Pravec et al. have estimated the shape and spin of Apophis from lightcurves that were collected at similar times as our radar data. The radar data were not strong enough for 3D shape modeling, but we used the Shape software (Hudson, Remote Sens. Rev. 8, 195-203, 1993 and Magri et al., Icarus 186, 152-177, 2007) to scale the convex lightcurve-derived shape model to fit the radar data. We find that the best ?2 value corresponds to the model that has 0.43×0.30×0.26 (±0.04, ±0.03, ±0.03) km for long, intermediate, and short axis, and a dynamically equivalent, equal volume ellipsoid of 0.31±0.03 km.

  15. Improving Ground Penetrating Radar Imaging in High Loss Environments by Coordinated System Development, Data Processing, Numerical Modeling, and Visualization methods with Applications to Site Characterization

    SciTech Connect

    David Wright; Michael Powers Charles Oden; Craig Moulton

    2006-10-07

    The Department of Energy has identified the location and characterization of subsurface contaminants and the charcterization of the subsurface as a priority need. Many DOE facilities are in need of subsurface imaging in the vadose and saturated zones.

  16. Space Radar Image of Prince Albert, Canada, seasonal

    NASA Technical Reports Server (NTRS)

    1994-01-01

    This is a comparison of images over Prince Albert, produced by the Spaceborne Imaging Radar-C and X-band Synthetic Aperture Radar aboard the space shuttle Endeavour on its 20th orbit on April 10, 1994, and again on orbit 20 of the second flight of Endeavour on October 1, 1994. The area is centered at 53.91 degrees north latitude and 104.69 degrees west longitude and is located 40 kilometers (25 miles) north and 30 kilometers (18.5 miles) east of the town of Prince Albert in the Saskatchewan province of Canada. The image covers the area east of Candle Lake, between the gravel highway of 120 and west of highway 106. The area imaged is near the southern limit of the boreal forest. The boreal forest of North America is a continuous vegetation belt at high latitudes stretching across the continent from the Atlantic shoreline of central Labrador and then westward across Canada to the interior mountains and central coastal plains of Alaska. The forest is also part of a larger northern hemisphere circumpolar boreal forest belt. Coniferous trees dominate the entire forest but deciduous trees are also present. During the month of April, the forest experiences seasonal changes from a frozen condition to a thawed condition. The trees are completely frozen over the winter season and the forest floor is covered by snow. As the average temperature rises in the spring, the trees are thawed and the snow melts. This transition has an impact on the rate of moisture evaporation and release of carbon dioxide into the atmosphere. In late September and early October, the boreal forest experiences a relatively different seasonal change. At this time, the leaves on deciduous trees start changing color and dropping off. The soil and trees are quite often moist due to frequent rainfall and cloud cover. The evaporation of moisture and carbon dioxide into the atmosphere also diminishes at this time. SIR-C/X-SAR is sensitive to the moisture of soil and vegetation and can sense this freeze-thaw cycle and the summer-fall seasonal transition over forested areas in particular. Optical sensors, by contrast, are blind to these regions, which are perpetually obscured by thick cloud cover. These changes were detected by comparing the April and October color composite images of L-band data in red, C-band data in green and X-band (vertically received and transmitted) in blue. The changes in intensity of each color over lakes, various forest stands and clear cuts in the two images is striking. Lakes such as Lake Heiberg, Crabtree Lake and Williams Lake, in the right middle part of the image, are frozen in April (appearing in bright blue) and melted (appearing in black) in October. The higher intensity of blue over lakes in April is due to low penetration of the X-band (vertically received and transmitted) and the radar's high sensitivity to surface features. Forest stands also exhibit major changes between the two images. The red areas in the October image are old jack pine canopies that cause higher return at L-band because of their moist condition in late summer compared to their partially frozen condition in April (in purple). Similarly, in the areas near the middle of the image, where black spruce and mixed aspen and jack pine trees dominate, the contrast between blue in October and red and green in April is an indication that the top of the canopy (needles and branches) were frozen in April and moist in October. The changes due to deforestation by logging companies or natural fires can also be detected by comparing the images. For example, the small blue area near the intersection of Harding Road and Highway 120 is the result of logging which occurred after the April data was acquired. The surface area of clear cut is approximately 4 hectares, which is calculated from the high-resolution capability of the radar images and verified by scientists participating in field work during the mission. 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, al

  17. Radar Imaging of Binary Near-Earth Asteroid 2004 DC

    NASA Astrophysics Data System (ADS)

    Taylor, Patrick A.; Margot, J. L.; Nolan, M. C.; Benner, L. A.; Ostro, S. J.; Giorgini, J. D.; Magri, C.

    2006-09-01

    Arecibo S-band (2380 MHz, 13 cm) and Goldstone X-band (8560 MHz, 3.5 cm) radar observations on June 2-6, 2006 show that Apollo asteroid 2004 DC is a binary system [IAU CBET 535]. Preliminary estimates of the diameters, based on visible range extents in the delay-Doppler images, are 300 m for the primary and 60 m for the secondary. The motion of the secondary in the delay-Doppler images suggests an orbital period of roughly 23 hours and a maximum primary-to-secondary separation of at least 0.6 km. The bandwidth of the primary increases from May 29 to June 3, then decreases until the end of observations on June 6, implying 2004 DC was viewed closest to equatorial on June 3. Assuming an equatorial view, the bandwidth suggests a rotation period of about 2 hours, which is in agreement with lightcurve observations [R. Behrend, pers. comm.]. The radar albedo and circular polarization ratio are 0.4 and 0.8 at S-band and 0.3 and unity at X-band. The circular polarization ratios are larger than those of the majority of radar-observed asteroids and imply that 2004 DC has extreme decimeter-scale near-surface roughness. We will estimate the parameters of the mutual orbit and the shape of the primary, and will place the orbital and physical properties of the system into the context of the existing binary near-Earth asteroid population.

  18. Shuttle synthetic aperture radar implementation study, volume 1. [flight instrument and ground data processor system for collecting raw imaged radar data

    NASA Technical Reports Server (NTRS)

    Mehlis, J. G.

    1976-01-01

    Results of an implementation study for a synthetic aperture radar for the space shuttle orbiter are described. The overall effort was directed toward the determination of the feasibility and usefulness of a multifrequency, multipolarization imaging radar for the shuttle orbiter. The radar is intended for earth resource monitoring as well as oceanographic and marine studies.

  19. Active laser radar (lidar) for measurement of corresponding height and reflectance images

    NASA Astrophysics Data System (ADS)

    Froehlich, Christoph; Mettenleiter, M.; Haertl, F.

    1997-08-01

    For the survey and inspection of environmental objects, a non-tactile, robust and precise imaging of height and depth is the basis sensor technology. For visual inspection,surface classification, and documentation purposes, however, additional information concerning reflectance of measured objects is necessary. High-speed acquisition of both geometric and visual information is achieved by means of an active laser radar, supporting consistent 3D height and 2D reflectance images. The laser radar is an optical-wavelength system, and is comparable to devices built by ERIM, Odetics, and Perceptron, measuring the range between sensor and target surfaces as well as the reflectance of the target surface, which corresponds to the magnitude of the back scattered laser energy. In contrast to these range sensing devices, the laser radar under consideration is designed for high speed and precise operation in both indoor and outdoor environments, emitting a minimum of near-IR laser energy. It integrates a laser range measurement system and a mechanical deflection system for 3D environmental measurements. This paper reports on design details of the laser radar for surface inspection tasks. It outlines the performance requirements and introduces the measurement principle. The hardware design, including the main modules, such as the laser head, the high frequency unit, the laser beam deflection system, and the digital signal processing unit are discussed.the signal processing unit consists of dedicated signal processors for real-time sensor data preprocessing as well as a sensor computer for high-level image analysis and feature extraction. The paper focuses on performance data of the system, including noise, drift over time, precision, and accuracy with measurements. It discuses the influences of ambient light, surface material of the target, and ambient temperature for range accuracy and range precision. Furthermore, experimental results from inspection of buildings, monuments and industrial environments are presented. The paper concludes by summarizing results achieved in industrial environments and gives a short outlook to future work.

  20. Space Shuttle Radar Images of Terrestrial Impact Structures: SIR-C/X-SAR

    NASA Astrophysics Data System (ADS)

    McHone, J. F.; Blumberg, D. G.; Greeley, R.; Underwood, J. R., Jr.

    1995-09-01

    The Spaceborne Radar Laboratory (SRL) orbited Earth in April and October of 1994 operating two imaging radars: X-SAR, an X-band (3 cm lambda) instrument, and the polarimetric SIR-C, a combination L-band/C-band (24 cm and 5.6 cm lambda). More than 150 terrestrial meteorite craters and astroblemes are presently known. Three of these, Wolfe Creek in Australia; Roter Kamm in Namibia; and Zhamanshin in Kazakhstan, were planned targets and were imaged successfully with multiple passes and look directions. Several other impact sites were fortuitously imaged while radar data were being collected for other purposes. These sites include B.P. and Oasis structures in Libya, Aourounga multi-ring feature in Chad, Amguid crater in Algeria, and the Spider astrobleme and Henbury crater field in Australia. Wolfe Creek (19 degrees 10'S; 127 degrees 47'E; 875 m dia) Both the elevated rim and the inner floor of this crater appear as radar bright features. Strong radar returns are due to blocky rubble textures in the rim and desert vegetation within the central bowl. Associated linear sand dunes show differential penetration properties in the various radar wavelengths and polarization. Roter Kamm (27 degrees 46'S; 016 degrees 18'E; 2.5 km dia) This bowl-shaped crater is mostly buried by wind-blown sands. Comparison of differential radar penetration patterns due to changes in wavelength and look direction reveal concealed target rocks and a buried possible ejecta unit. Zhamanshin (48 degrees 24'N; 060 degrees 48'E; 14 km dia) This unusual impact structure, first detected by the presence of glassy impact melt products [1], has very little topographic relief and is nearly invisible on survey-quality radar imagery. Fully processed images, however, enhance subtle vegetation patterns which highlight regional streams. These drainage patterns are now being analyzed in detail to better delineate boundaries and internal structure of this feature. B.P. Structure (25 degrees 19'N; 024 degrees 20'E; 2.8 km dia) Wind-blown sands which cover much of this relatively small feature make it difficult to distinguish from numerous dark sandstone outcrops using only optical images. Radar, however, penetrates the shallow sand mantle to reveal a nearly complete radar-bright bullseye pattern typical of central-uplift style impact structure. Oasis Structure (24 degrees 35'N; 24 degrees 24'E; >11.5 km dia) Oasis astrobleme was originally described as an elevated ring of sandstone some 5.1 km wide in desert sands. Examination of optical satellite images detected subtle concentric patterns more than 11 km across [2]. SIR-C images reveal strong arcuate reflectors buried beneath the sand at an even larger diameter of greater than 17 km. Aurounga (19 degrees 06'N; 019 degrees 15'E; 12.6 km dia) Although this highly circular depression has been noticed in numerous remote sensing studies, eg.[3], it usually has been associated with a large volcanic field and attributed to endogenic forces. Recent reports of shatter cones [4] and microscopic shock metamorphic effects [5] now demonstrate an impact origin. The radar-dark ring is a sand-filled trough which interupts a regional pattern of yardangs, wind-cut parallel ridges and grooves, developed in surrounding sandstones. Amguid (26 degrees 05'N; 004 degrees 23'E; 450 m dia) Situated in elevated rocky highlands [6], the small Amguid crater is nearly overprinted by surrounding radar backscatter. A dry central bowl is partially filled with smoothly surfaced fine-grained playa deposits which absorb radar energy and/or reflect it away from the spacecraft. The result is a distinct radar-dark disk within a bright regional ground clutter. Spider (16 degrees 44'S; 126 degrees 05'E; 13 km dia) Named for a radially splayed fault system in its center, Spider is the exposed root structure of a central-uplift impact feature [7]. Radar slope effects on processed data clearly delineate its size and internal complexity. Henbury craters (24 degrees 35'S; 133 degrees 09'E; largest ca.150 m dia) Although quite small, Henbury crater field [8] app

  1. HIGH SPECTRAL RESOLUTION LIDAR EMULATION VIA DOPPLER CLOUD RADAR SPECTRUM PROCESSING AND ITS IMPLICATIONS FOR

    E-print Network

    HIGH SPECTRAL RESOLUTION LIDAR EMULATION VIA DOPPLER CLOUD RADAR SPECTRUM PROCESSING AND ITS measurements of high spectral resolution lidar (HSRL) through processing of Doppler cloud radar spectra are sustainable. In this arena, the synergistic relationship of radar and lidar is often exploited, with lidar

  2. MULTI-MOMENT FORMULATION OF AUTOCONVERSION PROCESS AND THRESHOLD RADAR REFLECTIVITY

    E-print Network

    the autoconversion formulation to examine the threshold of radar reflectivity that separates precipitating cloudsMULTI-MOMENT FORMULATION OF AUTOCONVERSION PROCESS AND THRESHOLD RADAR REFLECTIVITY Yangang Liu from nonprecipitating clouds. An analytical expression that relates the reflectivity threshold

  3. Focused synthetic aperture radar processing of ice-sounder data collected over the Greenland ice sheet

    E-print Network

    Legarsky, J.; Gogineni, Sivaprasad; Akins, T. L.

    2001-10-01

    We developed a synthetic aperture radar (SAR) processing algorithm for airborne/spaceborne ice-sounding radar systems and applied it to data collected in Greenland. By using focused SAR (phase-corrected coherent averaging), we improved along...

  4. Range-imaging observations of cumulus convection and Kelvin-Helmholtz instabilities with the MU radar

    NASA Astrophysics Data System (ADS)

    Luce, H.; Hassenpflug, G.; Yamamoto, M.; Crochet, M.; Fukao, S.

    2007-02-01

    In the present work, we report observations of cumulus convection and Kelvin-Helmholtz (KH) instabilities in the troposphere at high vertical and time resolution with the middle and upper atmosphere (MU) radar (46.5 MHz, 34.85°N, 136.10°E, Japan). A detailed morphology of the structures could be obtained through application of range-imaging technique (called frequency radar interferometric imaging (FII) or range imaging (RIM)) with the Capon processing method. The usefulness of this work lies in the demonstration of the performance of the MU radar in range-imaging mode for investigating various atmospheric phenomena at small scales. As one case study, we describe the high-resolution echo pattern during a convective event. It is found that the convective cells formed in the early afternoon and reached a maximum altitude of about 3.5 km. The high-resolution images revealed thin layers above this altitude, unresolved at the standard 150-m low-resolution mode, associated with vertical oscillations possibly due to gravity waves generated by the convective cells through the mechanism of "obstacle effects." As a second case study, two clear images of KH billows and waves are shown. The KH billows were observed in the troposphere in regions of strong vertical shear of the horizontal wind and persisted for at least 20 min in both cases. The horizontal wavelengths of the KH waves were estimated to be about 2.5 and 5.7 km, according to the magnitude of the horizontal wind in the altitude range where the dynamic shear instabilities were observed.

  5. Multi-pixel high-resolution three-dimensional imaging radar

    NASA Technical Reports Server (NTRS)

    Cooper, Ken B. (Inventor); Dengler, Robert J. (Inventor); Siegel, Peter H. (Inventor); Chattopadhyay, Goutam (Inventor); Ward, John S. (Inventor); Juan, Nuria Llombart (Inventor); Bryllert, Tomas E. (Inventor); Mehdi, Imran (Inventor); Tarsala, Jan A. (Inventor)

    2012-01-01

    A three-dimensional imaging radar operating at high frequency e.g., 670 GHz radar using low phase-noise synthesizers and a fast chirper to generate a frequency-modulated continuous-wave (FMCW) waveform, is disclosed that operates with a multiplexed beam to obtain range information simultaneously on multiple pixels of a target. A source transmit beam may be divided by a hybrid coupler into multiple transmit beams multiplexed together and directed to be reflected off a target and return as a single receive beam which is demultiplexed and processed to reveal range information of separate pixels of the target associated with each transmit beam simultaneously. The multiple transmit beams may be developed with appropriate optics to be temporally and spatially differentiated before being directed to the target. Temporal differentiation corresponds to a different intermediate frequencies separating the range information of the multiple pixels. Collinear transmit beams having differentiated polarizations may also be implemented.

  6. A comparison of spatial sampling techniques enabling first principles modeling of a synthetic aperture RADAR imaging platform

    E-print Network

    Gartley, Michael G.

    different ways. One method treats a scene as a radar cross section (RCS) map and simply evaluates the radar aperture RADAR imaging platform Michael Gartley*a , Adam Goodenougha , Scott Browna , Russel P. Kauffmanb, Philadelphia PA, 19101; ABSTRACT Simulation of synthetic aperture radar (SAR) imagery may be approached in many

  7. ERTS computer compatible tape data processing and analysis. Appendix 1: The utility of imaging radars for the study of lake ice

    NASA Technical Reports Server (NTRS)

    Polcyn, F. C.; Thomson, F. J.; Porcello, L. J.; Sattinger, I. J.; Malila, W. A.; Wezernak, C. T.; Horvath, R.; Vincent, R. K. (principal investigators); Bryan, M. L.

    1972-01-01

    There are no author-identified significant results in this report. Remotely sensed multispectral scanner and return beam vidicon imagery from ERTS-1 is being used for: (1) water depth measurements in the Virgin Islands and Upper Lake Michigan areas; (2) mapping of the Yellowstone National Park; (3) assessment of atmospheric effects in Colorado; (4) lake ice surveillance in Canada and Great Lakes areas; (5) recreational land use in Southeast Michigan; (6) International Field Year on the Great Lakes investigations of Lake Ontario; (7) image enhancement of multispectral scanner data using existing techniques; (8) water quality monitoring of the New York Bight, Tampa Bay, Lake Michigan, Santa Barbara Channel, and Lake Erie; (9) oil pollution detection in the Chesapeake Bay, Gulf of Mexico southwest of New Orleans, and Santa Barbara Channel; and (10) mapping iron compounds in the Wind River Mountains.

  8. Using Centimetric Visible Imagery Obtained from an UAV Quadrotor for Classification of Radar Images

    NASA Astrophysics Data System (ADS)

    Gademer, A.; Petitpas, B.; Beaudoin, L.; Roux, M.; Tanzi, T.; Riera, B.; Rudant, J. P.

    2010-12-01

    Interpreting remote sensing images, and SAR images in particular, is often a challenging task. The aim of this article is to explore how visible centimetre information taken from an Unmanned Vehicle System (UAS) could help in interpretation of radar images. After nearly two decades of operational use, it is very common to work with radar images like the ERS ones. Obtaining visible centimetre images on a particular scene is a more complicated task. To face this difficulty, we have developed a small scale UAV dedicated to low altitude aerial remote sensing. From the stereo pair acquired, we have computed dense disparity maps and deduced some roughness parameters. As there is a direct link between the soil roughness, the soil moisture and the radar backscattering, we think that theses measures can have a high added-valued to interpret generic radar images and even the amplitude and coherence images obtained during the interferometric treatment.

  9. Determining titan's spin state from cassini radar images

    USGS Publications Warehouse

    Stiles, B.W.; Kirk, R.L.; Lorenz, R.D.; Hensley, S.; Lee, E.; Ostro, S.J.; Allison, M.D.; Callahan, P.S.; Gim, Y.; Iess, L.; Del Marmo, P.P.; Hamilton, G.; Johnson, W.T.K.; West, R.D.

    2008-01-01

    For some 19 areas of Titan's surface, the Cassini RADAR instrument has obtained synthetic aperture radar (SAR) images during two different flybys. The time interval between flybys varies from several weeks to two years. We have used the apparent misregistration (by 10-30 km) of features between separate flybys to construct a refined model of Titan's spin state, estimating six parameters: north pole right ascension and declination, spin rate, and these quantities' first time derivatives We determine a pole location with right ascension of 39.48 degrees and declination of 83.43 degrees corresponding to a 0.3 degree obliquity. We determine the spin rate to be 22.5781 deg day -1 or 0.001 deg day-1 faster than the synchronous spin rate. Our estimated corrections to the pole and spin rate exceed their corresponding standard errors by factors of 80 and 8, respectively. We also found that the rate of change in the pole right ascension is -30 deg century-1, ten times faster than right ascension rate of change for the orbit normal. The spin rate is increasing at a rate of 0.05 deg day -1 per century. We observed no significant change in pole declination over the period for which we have data. Applying our pole correction reduces the feature misregistration from tens of km to 3 km. Applying the spin rate and derivative corrections further reduces the misregistration to 1.2 km. ?? 2008. The American Astronomical Society. All rights reserved.

  10. Three-dimensional subsurface imaging synthetic aperture radar

    SciTech Connect

    Moussally, G.J.

    1995-03-01

    The objective of this applied research and development project is to develop a system known as `3-D SISAR`. This system consists of a ground penetrating radar with software algorithms designed for the detection, location, and identification of buried objects in the underground hazardous waste environments found at DOE storage sites. Three-dimensional maps of the object locations will be produced which can assist the development of remediation strategies and the characterization of the digface during remediation operations. It is expected that the 3-D SISAR will also prove useful for monitoring hydrocarbon based contaminant migration after remediation. The underground imaging technique being developed under this contract utilizes a spotlight mode Synthetic Aperture Radar (SAR) approach which, due to its inherent stand-off capability, will permit the rapid survey of a site and achieve a high degree of productivity over large areas. When deployed from an airborne platform, the stand-off techniques is also seen as a way to overcome practical survey limitations encountered at vegetated sites.

  11. Three-dimensional radar imaging of atmospheric layer and turbulence structures using multiple receivers and multiple frequencies

    NASA Astrophysics Data System (ADS)

    Chen, J.-S.; Furumoto, J.; Yamamoto, M.

    2014-08-01

    The pulsed, beamwidth-limited atmospheric radar suffers from a finite resolution volume, making it difficult to resolve the small-scale irregularity structure of refractive index (or clear-air turbulence) in the scattering region. Multi-receiver and multi-frequency imaging techniques were thus proposed to improve the spatial resolution of the measurements in the finite resolution volume. The middle and upper atmosphere radar (MUR; 34.85° N, 136.10° N) possesses the capabilities of 5 frequencies, ranging from 46 MHz to 47 MHz, and up to 25 receivers to carry out the imaging techniques. In this paper, we exhibit the three-dimensional (3-D) radar imaging utilizing five frequencies and 19 receivers of the MUR. The Capon method was employed for the process of imaging, and examinations of a wavy layer and turbulent structures were made, in which the spatial weighting effect on the imaging were mitigated beforehand. Information such as echo center and structure morphology in the resolution volume was then extracted. For example, the location distribution of echo centers could imply the traveling orientation of the wavy layer, which was correspondent with horizontal wind direction. Such information of wavy layer structure was more difficult to disclose without removal of the spatial weighting effect. This paper demonstrates an advanced application of 3-D radar imaging to some practical atmospheric phenomena.

  12. A system for the real-time display of radar and video images of targets

    NASA Technical Reports Server (NTRS)

    Allen, W. W.; Burnside, W. D.

    1990-01-01

    Described here is a software and hardware system for the real-time display of radar and video images for use in a measurement range. The main purpose is to give the reader a clear idea of the software and hardware design and its functions. This system is designed around a Tektronix XD88-30 graphics workstation, used to display radar images superimposed on video images of the actual target. The system's purpose is to provide a platform for tha analysis and documentation of radar images and their associated targets in a menu-driven, user oriented environment.

  13. Change Detection in Synthetic Aperture Radar Images Based on Deep Neural Networks.

    PubMed

    Gong, Maoguo; Zhao, Jiaojiao; Liu, Jia; Miao, Qiguang; Jiao, Licheng

    2016-01-01

    This paper presents a novel change detection approach for synthetic aperture radar images based on deep learning. The approach accomplishes the detection of the changed and unchanged areas by designing a deep neural network. The main guideline is to produce a change detection map directly from two images with the trained deep neural network. The method can omit the process of generating a difference image (DI) that shows difference degrees between multitemporal synthetic aperture radar images. Thus, it can avoid the effect of the DI on the change detection results. The learning algorithm for deep architectures includes unsupervised feature learning and supervised fine-tuning to complete classification. The unsupervised feature learning aims at learning the representation of the relationships between the two images. In addition, the supervised fine-tuning aims at learning the concepts of the changed and unchanged pixels. Experiments on real data sets and theoretical analysis indicate the advantages, feasibility, and potential of the proposed method. Moreover, based on the results achieved by various traditional algorithms, respectively, deep learning can further improve the detection performance. PMID:26068879

  14. An image-based approach for classification of human micro-doppler radar signatures

    NASA Astrophysics Data System (ADS)

    Tivive, Fok Hing Chi; Phung, Son Lam; Bouzerdoum, Abdesselam

    2013-05-01

    With the advances in radar technology, there is an increasing interest in automatic radar-based human gait identification. This is because radar signals can penetrate through most dielectric materials. In this paper, an image-based approach is proposed for classifying human micro-Doppler radar signatures. The time-varying radar signal is first converted into a time-frequency representation, which is then cast as a two-dimensional image. A descriptor is developed to extract micro-Doppler features from local time-frequency patches centered along the torso Doppler frequency. Experimental results based on real data collected from a 24-GHz Doppler radar showed that the proposed approach achieves promising classification performance.

  15. 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.

  16. 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.

  17. 1796 IEEE TRANSACTIONS ON SIGNAL PROCESSING, VOL. 62, NO. 7, APRIL 1, 2014 Sub-Nyquist Radar via Doppler Focusing

    E-print Network

    Eldar, Yonina

    of a monostatic pulse-Doppler radar transceiver trying to detect targets sparsely populated in the radar in a pulse-Doppler radar system, using sub-Nyquist sampling rates. The radar is a single transceiver1796 IEEE TRANSACTIONS ON SIGNAL PROCESSING, VOL. 62, NO. 7, APRIL 1, 2014 Sub-Nyquist Radar via

  18. Development of signal processing methods for imaging buried pipes

    SciTech Connect

    Michiguchi, Y.; Hiramoto, K.; Nishi, M.; Takahashi, F.; Ohtaka, T.; Okada, M.

    1987-01-01

    A new imaging technique for subsurface radars is described for reconstructing clear images of buried pipes in soil. The method developed has two signal processing stages; preprocessing and aperture synthesis. The preprocessing extracts signals scattered from the pipes by reducing clutter noise. The synthetic-aperture processing analyzes only the scattered signals derived by the first stage and reconstructs high-quality images in a short processing time. The imaging technique developed was successfully applied to the imaging of actual buried metallic pipes. It was experimentally confirmed that the new imaging method was capable of reconstructing clear images in a short time without losing image quality.

  19. Hyperspectral image processing

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Hyperspectral image processing refers to the use of computer algorithms to extract, store and manipulate both spatial and spectral information contained in hyperspectral images across the visible and near-infrared portion of the electromagnetic spectrum. A typical hyperspectral image processing work...

  20. Noise analysis for near-field 3D FM-CW radar imaging systems

    NASA Astrophysics Data System (ADS)

    Sheen, David M.

    2015-05-01

    Near field radar imaging systems are used for demanding security applications including concealed weapon detection in airports and other high-security venues. Despite the near-field operation, phase noise and thermal noise can limit performance in several ways. Practical imaging systems can employ arrays with low gain antennas and relatively large signal distribution networks that have substantial losses which limit transmit power and increase the effective noise figure of the receiver chain, resulting in substantial thermal noise. Phase noise can also limit system performance. The signal coupled from transmitter to receiver is much larger than expected target signals. Phase noise from this coupled signal can set the system noise floor if the oscillator is too noisy. Frequency modulated continuous wave (FM-CW) radar transceivers used in short range systems are relatively immune to the effects of the coupled phase noise due to range correlation effects. This effect can reduce the phase-noise floor such that it is below the thermal noise floor for moderate performance oscillators. Phase noise is also manifested in the range response around bright targets, and can cause smaller targets to be obscured. Noise in synthetic aperture imaging systems is mitigated by the processing gain of the system. In this paper, the effects of thermal noise, phase noise, and processing gain are analyzed in the context of a near field 3-D FM-CW imaging radar as might be used for concealed weapon detection. In addition to traditional frequency domain analysis, a time-domain simulation is employed to graphically demonstrate the effect of these noise sources on a fast-chirping FM-CW system.

  1. Probability of acquisition of three-dimensional imaging laser radar

    NASA Astrophysics Data System (ADS)

    Dong, Li-jun; Zhu, Shao-lan; Sun, Chuan-dong; Gao, Cun-xiao; Song, Zhi-yuan

    2011-06-01

    Three-dimensional imaging laser radar (3-D ladar) is widely used in area of modern military, scientific research, agriculture and industry. Because of its many features such as angle-angle-range capturing, high resolution, anti-jamming ability and no multipath effect ,but it has to scan for target searching, acquiring and tracking. This paper presents a novel probability model of target acquiring which provides a theoretical basis for optimizing the scanning mechanism. The model combines space and time, target moving velocity and ladar scanning velocity together. Then the optimum scanning mechanism to obtain the maximum probability of acquisition and associated with different targets can be gained. The result shows that this model provides a method to optimize parameter for designing of the scanner.

  2. Spatially assisted down-track median filter for GPR image post-processing

    SciTech Connect

    Paglieroni, David W; Beer, N Reginald

    2014-10-07

    A method and system for detecting the presence of subsurface objects within a medium is provided. In some embodiments, the imaging and detection system operates in a multistatic mode to collect radar return signals generated by an array of transceiver antenna pairs that is positioned across the surface and that travels down the surface. The imaging and detection system pre-processes the return signal to suppress certain undesirable effects. The imaging and detection system then generates synthetic aperture radar images from real aperture radar images generated from the pre-processed return signal. The imaging and detection system then post-processes the synthetic aperture radar images to improve detection of subsurface objects. The imaging and detection system identifies peaks in the energy levels of the post-processed image frame, which indicates the presence of a subsurface object.

  3. Bistatic SAR: Signal Processing and Image Formation.

    SciTech Connect

    Wahl, Daniel E.; Yocky, David A.

    2014-10-01

    This report describes the significant processing steps that were used to take the raw recorded digitized signals from the bistatic synthetic aperture RADAR (SAR) hardware built for the NCNS Bistatic SAR project to a final bistatic SAR image. In general, the process steps herein are applicable to bistatic SAR signals that include the direct-path signal and the reflected signal. The steps include preprocessing steps, data extraction to for a phase history, and finally, image format. Various plots and values will be shown at most steps to illustrate the processing for a bistatic COSMO SkyMed collection gathered on June 10, 2013 on Kirtland Air Force Base, New Mexico.

  4. Automatic position calculating imaging radar with low-cost synthetic aperture sensor for imaging layered media

    DOEpatents

    Mast, J.E.

    1998-08-18

    An imaging system for analyzing structures comprises a radar transmitter and receiver connected to a timing mechanism that allows a radar echo sample to be taken at a variety of delay times for each radar pulse transmission. The radar transmitter and receiver are coupled to a position determining system that provides the x,y position on a surface for each group of samples measured for a volume from the surface. The radar transmitter and receiver are moved about the surface to collect such groups of measurements from a variety of x,y positions. Return signal amplitudes represent the relative reflectivity of objects within the volume and the delay in receiving each signal echo represents the depth at which the object lays in the volume and the propagation speeds of the intervening material layers. Successively deeper z-planes are backward propagated from one layer to the next with an adjustment for variations in the expected propagation velocities of the material layers that lie between adjacent z-planes. 10 figs.

  5. Automatic position calculating imaging radar with low-cost synthetic aperture sensor for imaging layered media

    DOEpatents

    Mast, Jeffrey E. (Livermore, CA)

    1998-01-01

    An imaging system for analyzing structures comprises a radar transmitter and receiver connected to a timing mechanism that allows a radar echo sample to be taken at a variety of delay times for each radar pulse transmission. The radar transmitter and receiver are coupled to a position determining system that provides the x,y position on a surface for each group of samples measured for a volume from the surface. The radar transmitter and receiver are moved about the surface to collect such groups of measurements from a variety of x,y positions. Return signal amplitudes represent the relative reflectivity of objects within the volume and the delay in receiving each signal echo represents the depth at which the object lays in the volume and the propagation speeds of the intervening material layers. Successively deeper z-planes are backward propagated from one layer to the next with an adjustment for variations in the expected propagation velocities of the material layers that lie between adjacent z-planes.

  6. Subroutines For Image Processing

    NASA Technical Reports Server (NTRS)

    Faulcon, Nettie D.; Monteith, James H.; Miller, Keith W.

    1988-01-01

    Image Processing Library computer program, IPLIB, is collection of subroutines facilitating use of COMTAL image-processing system driven by HP 1000 computer. Functions include addition or subtraction of two images with or without scaling, display of color or monochrome images, digitization of image from television camera, display of test pattern, manipulation of bits, and clearing of screen. Provides capability to read or write points, lines, and pixels from image; read or write at location of cursor; and read or write array of integers into COMTAL memory. Written in FORTRAN 77.

  7. Investigation of image enhancement techniques for the development of a self-contained airborne radar navigation system

    NASA Technical Reports Server (NTRS)

    Phatak, A. V.; Karmali, M. S.

    1983-01-01

    This study was devoted to an investigation of the feasibility of applying advanced image processing techniques to enhance radar image characteristics that are pertinent to the pilot's navigation and guidance task. Millimeter (95 GHz) wave radar images for the overwater (i.e., offshore oil rigs) and overland (Heliport) scenario were used as a data base. The purpose of the study was to determine the applicability of image enhancement and scene analysis algorithms to detect and improve target characteristics (i.e., manmade objects such as buildings, parking lots, cars, roads, helicopters, towers, landing pads, etc.) that would be helpful to the pilot in determining his own position/orientation with respect to the outside world and assist him in the navigation task. Results of this study show that significant improvements in the raw radar image may be obtained using two dimensional image processing algorithms. In the overwater case, it is possible to remove the ocean clutter by thresholding the image data, and furthermore to extract the target boundary as well as the tower and catwalk locations using noise cleaning (e.g., median filter) and edge detection (e.g., Sobel operator) algorithms.

  8. Thermal-wave radar: A novel subsurface imaging modality with extended depth-resolution dynamic range

    E-print Network

    Mandelis, Andreas

    in the dynamic range when using the thermal-wave radar TWR instead of conventional PTR. A practical TWR image-called thermal-wave radar TWR method is able to detect inhomo- geneities far beneath the effective detection range of conven- tional PTR. TWR has the potential to be used in biomedical applications, since it can

  9. Microwave penetration and attenuation in desert soil - A field experiment with the Shuttle Imaging Radar

    NASA Technical Reports Server (NTRS)

    Farr, T. G.; Elachi, C.; Hartl, P.; Chowdhury, K.

    1986-01-01

    Receivers buried in the Nevada desert were used with the Shuttle Imaging Radar to measure microwave attenuation as a function of soil moisture in situ. Results agree closely with laboratory measurements of attenuation and suggest that penetration of tens of centimeters in desert soils is common for L-band (1.2-GHz) radar.

  10. PERFORMANCE ANALYSIS OF MEASUREMENT ERROR REGRESSION IN DIRECT-DETECTION LASER RADAR IMAGING

    E-print Network

    Gustafsson, Fredrik

    PERFORMANCE ANALYSIS OF MEASUREMENT ERROR REGRESSION IN DIRECT-DETECTION LASER RADAR IMAGING Christina Grönwall, Tomas Carlsson Swedish Defence Research Agency (FOI) Department of Laser Systems P@isy.liu.se ABSTRACT In this paper a tool for synthetic generation of scan- ning laser radar data is described and its

  11. Three-dimensional monopulse radar imaging simulation of ships on sea surfaces

    NASA Astrophysics Data System (ADS)

    Guijie, Diao; Xu, Xiaojian

    2012-09-01

    The signal model of wideband monopulse radar is developed according to spotlight synthetic aperture radar (SAR) geometry to study the three-dimensional (3-D) imaging for ship targets on sea surface. An efficient 3-D monopulse imaging algorithm based on multi-frame one-dimensional (1-D) high resolution range profiles (HRRP) is proposed, where no complex phase compensation is needed. Simulation results validate the algorithm and show that the reconstructed 3-D images represent more detailed backscattering characteristics of the targets, demonstrating promising features for radar recognition.

  12. Seasat views North America, the Caribbean, and Western Europe with imaging radar

    NASA Technical Reports Server (NTRS)

    Ford, J. P.; Blom, R. G.; Bryan, M. L.; Daily, M.; Dixon, T. H.; Elachi, C.; Xenos, E. C.

    1980-01-01

    Forty-one digitally correlated Seasat synthetic-aperture radar images of land areas in North America, the Caribbean, and Western Europe are presented to demonstrate this microwave orbital imagery. The characteristics of the radar images, the types of information that can be extracted from them, and certain of their inherent distortions are briefly described. Each atlas scene covers an area of 90 X 90 kilometers, with the exception of the one that is the Nation's Capital. The scenes are grouped according to salient features of geology, hydrology and water resources, urban landcover, or agriculture. Each radar image is accompanied by a corresponding image in the optical or near-infrared range, or by a simple sketch map to illustrate features of interest. Characteristics of the Seasat radar imaging system are outlined.

  13. A model for forming airborne synthetic aperture radar images of underground targets

    SciTech Connect

    Doerry, A.W.

    1994-01-01

    Synthetic Aperture Radar (SAR) from an airborne platform has been proposed for imaging targets beneath the earth`s surface. The propagation of the radar`s energy within the ground, however, is much different than in the earth`s atmosphere. The result is signal refraction, echo delay, propagation losses, dispersion, and volumetric scattering. These all combine to make SAR image formation from an airborne platform much more challenging than a surface imaging counterpart. This report treats the ground as a lossy dispersive half-space, and presents a model for the radar echo based on measurable parameters. The model is then used to explore various imaging schemes, and image properties. Dynamic range is discussed, as is the impact of loss on dynamic range. Modified window functions are proposed to mitigate effects of sidelobes of shallow targets overwhelming deeper targets.

  14. An investigation of ionospheric irregularity effects on SIR-B image processing and information extraction

    NASA Technical Reports Server (NTRS)

    Szuszczewicz, E. P.; Abdu, M. A.; Sobral, J. H. A.; Jost, J.; Reddy, B. M.; Rino, C.; Robinson, T.; Rodrigues, P.; Singh, M.; Woodman, R.

    1984-01-01

    Ionospheric irregularities and associated effects on space-time synthetic aperture radar (SAR) image processing and information extraction, including sensor calibration, target statistics determination, resolution, distortion, and overall image integrity were investigated.

  15. Standoff concealed weapon detection using a 350 GHz radar imaging system

    SciTech Connect

    Sheen, David M.; Hall, Thomas E.; Severtsen, Ronald H.; McMakin, Douglas L.; Hatchell, Brian K.; Valdez, Patrick LJ

    2010-04-01

    The Pacific Northwest National Laboratory is currently developing a 350 GHz, active, wideband, three-dimensional, radar imaging system to evaluate the feasibility of active sub-mm imaging for standoff concealed weapon detection. The prototype radar imaging system is based on a wideband, heterodyne, frequency-multiplier-based transceiver system coupled to a quasi-optical focusing system and high-speed rotating conical scanner. The wideband operation of this system provides accurate ranging information, and the images obtained are fully three-dimensional. Recent improvements to the system include increased imaging speed using improved balancing techniques, wider bandwidth, and image display techniques.

  16. Orbital Imaging Radar and the Search for Water on Mars

    NASA Technical Reports Server (NTRS)

    Campbell, B. A.; Campbell, D. B.; Grant, J. A.; Hensley, S.; Maxwell, T. A.; Plaut, J. J.; Rosen, P.; Shepard, M. K.; Simpson, R.

    2001-01-01

    The surface of Mars has been modified by a range of geologic processes, and many regions are mantled by varying depths of wind-blown dust, volcanic ash, and fluvially deposited or other water-lain sediments. We are proposing an orbital mission carrying a synthetic aperture radar (SAR) that can penetrate a significant depth of overlying material to reveal the detailed geomorphology as it relates to the changing fluvial, eolian, volcanic, and cratering history of Mars. Moreover, the data to be returned are of direct relevance to the search for past and present occurrences of liquid water, life, changing martian climate, and geologic history (e.g., origin of the northern plains, mechanisms for past and possible present valley formation, and genesis of widespread mantling deposits), the validation of potential landing sites for rover safety, and evaluation of sub-surface accessibility for drilling.

  17. Research on high precision timing system based on FPGA non scanning imaging laser radar

    NASA Astrophysics Data System (ADS)

    Fu, Yanbo; Han, Shaokun; Wang, Liang; Ma, Yayun

    2015-08-01

    The article introduced the system structure and imaging principle of no three-dimensional imaging laser radar. This paper used the XC7K325T XILINX chip of KINTEX 7 series and used temporal interpolation method to measure distance. Rough side used PLL multiplier 400MHZ, which reached 2.5ns time accuracy. This method used a thin chip delay chains carry resources to reach 50ps accuracy and greatly improved the accuracy of the timing of imaging. Application technique used a delay line in APD array imaging system, such that each channel distance accuracy greatly improved. Echo signal by photoelectric conversion is completed by APD array detector, and designed by the impedance amplifier and other analog signal processing circuit. FPGA signal processing circuit is to complete the back-end processing, which is the timing function. FPGA array timer clock is to achieve coarse portion through timing, and delay line technique for measuring the length of time a non-integer multiple of the period of the laser pulse emission and the moment of reception, each stage of the delay units delay accuracy of sub ns magnitude, so as to achieve precision measuring part timers. With the above device was close imaging experiments, obtaining the 5 × 5 pixel imaging test results, presented to further improve system accuracy improved method.

  18. A neural network for enhancing boundaries and surfaces in synthetic aperture radar images.

    PubMed

    Mingolla, Ennio; Ross, William; Grossberg, Stephen

    1999-04-01

    A neural network system for boundary segmentation and surface representation, inspired by a new local-circuit model of visual processing in the cerebral cortex, is used to enhance images of range data gathered by a synthetic aperture radar (SAR) sensor. Boundary segmentation is accomplished by an improved Boundary Contour System (BCS) model which completes coherent boundaries that retain their sensitivity to image contrasts and locations. A Feature Contour System (FCS) model compensates for local contrast variations and uses the compensated signals to diffusively fill-in surface regions within the BCS boundaries. Image noise pixels that are not supported by BCS boundaries are hereby eliminated. More generally, BCS/FCS processing normalizes input dynamic range, reduces noise, and enhances contrasts between surface regions. BCS/FCS processing hereby makes structures such as motor vehicles, roads, and buildings more salient to human observers than in original imagery. The new BCS model improves image enhancement with significant reductions in processing time and complexity over previous BCS applications. The new system also outperforms several established techniques for image enhancement. PMID:12662691

  19. Martian CAT scan: Three-dimensional imaging of Planum Boreum with Shallow Radar data

    NASA Astrophysics Data System (ADS)

    Putzig, N. E.; Foss, F. J., II; Campbell, B. A.; Phillips, R. J.

    2012-12-01

    We present a preliminary three-dimensional (3-D) subsurface volume created from Shallow Radar (SHARAD) observations of Planum Boreum, the 3-km-high mound of icy layered deposits in the north polar region of Mars. Our goal is to achieve a better understanding of the nature and timing of the layered deposits and their relationship to climatological cycles by enabling the mapping of subsurface radar returns in regions presently obfuscated by highly variable surface topography and complex subsurface structures. In the medical field, computed axial tomography (CAT scan) involves taking a series of 2-D X-ray images around an axis of rotation and applying geometric processing to generate a 3-D image of a body's interior. Similarly, SHARAD has taken over 2500 2-D radar images (radargrams) on passes of the Mars Reconnaissance Orbiter (MRO) across the north polar region of Mars, and we have used a subset of those radargrams to develop a means of generating 3-D images of the polar layered deposits. While the sets of radargrams over both polar regions have been very fruitful scientifically (e.g., Putzig et al., 2009, Icarus 204, 443-457; Holt et al., 2010, Nature 465, 450-453; Phillips et al., 2011, Science 332, 838-841), examination of 3-D subsurface structures has been restricted to identifying and tracing those structures on the radargrams and then "connecting the dots" by interpolation. Identification and tracing of structures is limited to the trajectories of MRO's nadir track and is hampered by "clutter," or signals returned from off-nadir surface or subsurface features that often interfere with signals returned from nadir. Clutter becomes a severe impediment to structure interpretation in areas of high topographic variability, such as the trough-rich regions of Planum Boreum. Given a sufficient number of observations from a range of lateral offsets, radar signals from nadir and off-nadir can be distinguished within a 3-D volume, and off-nadir clutter can be repositioned and promoted to signal in its source location. Such 3-D imaging techniques are well developed not only in the medical field but also in terrestrial subsurface radar and seismic studies, where they are commonly referred to as "migration." Available 3-D imaging software requires that the data first be binned into a 3-D grid and co-registered to a common datum. For SHARAD, the Martian ionosphere introduces a complication in that it significantly distorts and delays the radar signals on the sunlit side of the planet. To address phase distortion, we apply an autofocus technique (Campbell et al., 2011, IEEE Geosci. Remote Sens. Lett. 8, No. 5) that relies on an empirically derived phase correction of the SHARAD signal and optimization of an image-quality metric over 100-km segments of each affected radargram. This method also allows us to estimate the along-track variable delays introduced by the ionosphere. We remove any residual delays using a correlation technique applied to the data subsequent to the 3-D binning step. At that point, we proceed to migration of the data, yielding a geometrically corrected 3-D volume of SHARAD data.

  20. Joint anisotropy characterization and image formation in wide-angle synthetic aperture radar

    E-print Network

    Varshney, Kush R. (Kush Raj)

    2006-01-01

    Imagery formed from wide-angle synthetic aperture radar (SAR) measurements has fine cross-range resolution in principle. However, conventional SAR image formation techniques assume isotropic scattering, which is not valid ...

  1. Two-stage radar image despeckling based on local statistic Lee and sigma filtering

    NASA Astrophysics Data System (ADS)

    Lukin, Vladimir V.; Ponomarenko, Nikolay N.; Alekseyev, Leonid Y.; Melnik, Vladimir P.; Astola, Jaakko T.

    2001-05-01

    The peculiarities of radar images and the problems of their filtering are considered. A two-stage procedure of radar image despeckling based on successive application of the local statistic Lee and sigma filters is proposed. The recommendations concerning filter parameter selection are presented. The performance characteristics of the proposed procedure are evaluated for a set of test artificial images. It is shown that the two-stage despeckling can be successfully applied to both images formed by side look aperture radar (SLAR) or synthetic aperture radar (SAR). An available trade-off of filter basic properties is provided. The examples for real data demonstrating the proposed procedure efficiency and benefits are also given.

  2. Sparsity-Driven Synthetic Aperture Radar Imaging: Reconstruction, autofocusing, moving targets, and compressed sensing

    E-print Network

    Cetin, Mujdat

    This article presents a survey of recent research on sparsity-driven synthetic aperture radar (SAR) imaging. In particular, it reviews 1) the analysis and synthesis-based sparse signal representation formulations for SAR ...

  3. 47 CFR 15.509 - Technical requirements for ground penetrating radars and wall imaging systems.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 15.509 Section 15.509 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL RADIO FREQUENCY DEVICES Ultra-Wideband Operation § 15.509 Technical requirements for ground penetrating radars and wall imaging systems....

  4. 47 CFR 15.509 - Technical requirements for ground penetrating radars and wall imaging systems.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 15.509 Section 15.509 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL RADIO FREQUENCY DEVICES Ultra-Wideband Operation § 15.509 Technical requirements for ground penetrating radars and wall imaging systems....

  5. 47 CFR 15.509 - Technical requirements for ground penetrating radars and wall imaging systems.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 15.509 Section 15.509 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL RADIO FREQUENCY DEVICES Ultra-Wideband Operation § 15.509 Technical requirements for ground penetrating radars and wall imaging systems....

  6. 47 CFR 15.509 - Technical requirements for ground penetrating radars and wall imaging systems.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 15.509 Section 15.509 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL RADIO FREQUENCY DEVICES Ultra-Wideband Operation § 15.509 Technical requirements for ground penetrating radars and wall imaging systems....

  7. 47 CFR 15.509 - Technical requirements for ground penetrating radars and wall imaging systems.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 15.509 Section 15.509 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL RADIO FREQUENCY DEVICES Ultra-Wideband Operation § 15.509 Technical requirements for ground penetrating radars and wall imaging systems....

  8. Development of an electronically tunable ultra-wideband radar imaging sensor and its components 

    E-print Network

    Han, Jeongwoo

    2006-08-16

    Novel microwave transmitter and receiver circuits have been developed for implementing UWB (Ultra-Wideband) impulse radar imaging sensor operating in frequency band 0.2 to 4 GHz. with tunable operating frequency band. The fundamental system design...

  9. Image processing mini manual

    NASA Technical Reports Server (NTRS)

    Matthews, Christine G.; Posenau, Mary-Anne; Leonard, Desiree M.; Avis, Elizabeth L.; Debure, Kelly R.; Stacy, Kathryn; Vonofenheim, Bill

    1992-01-01

    The intent is to provide an introduction to the image processing capabilities available at the Langley Research Center (LaRC) Central Scientific Computing Complex (CSCC). Various image processing software components are described. Information is given concerning the use of these components in the Data Visualization and Animation Laboratory at LaRC.

  10. Apple Image Processing Educator

    NASA Technical Reports Server (NTRS)

    Gunther, F. J.

    1981-01-01

    A software system design is proposed and demonstrated with pilot-project software. The system permits the Apple II microcomputer to be used for personalized computer-assisted instruction in the digital image processing of LANDSAT images. The programs provide data input, menu selection, graphic and hard-copy displays, and both general and detailed instructions. The pilot-project results are considered to be successful indicators of the capabilities and limits of microcomputers for digital image processing education.

  11. High-resolution imaging using a wideband MIMO radar system with two distributed arrays.

    PubMed

    Wang, Dang-wei; Ma, Xiao-yan; Chen, A-Lei; Su, Yi

    2010-05-01

    Imaging a fast maneuvering target has been an active research area in past decades. Usually, an array antenna with multiple elements is implemented to avoid the motion compensations involved in the inverse synthetic aperture radar (ISAR) imaging. Nevertheless, there is a price dilemma due to the high level of hardware complexity compared to complex algorithm implemented in the ISAR imaging system with only one antenna. In this paper, a wideband multiple-input multiple-output (MIMO) radar system with two distributed arrays is proposed to reduce the hardware complexity of the system. Furthermore, the system model, the equivalent array production method and the imaging procedure are presented. As compared with the classical real aperture radar (RAR) imaging system, there is a very important contribution in our method that the lower hardware complexity can be involved in the imaging system since many additive virtual array elements can be obtained. Numerical simulations are provided for testing our system and imaging method. PMID:20051345

  12. Imaging laser radar for high-speed monitoring of the environment

    NASA Astrophysics Data System (ADS)

    Froehlich, Christoph; Mettenleiter, M.; Haertl, F.

    1998-01-01

    In order to establish mobile robot operations and to realize survey and inspection tasks, robust and precise measurements of the geometry of the 3D environment is the basis sensor technology. For visual inspection, surface classification, and documentation purposes, however, additional information concerning reflectance of measured objects is necessary. High-speed acquisition of both geometric and visual information is achieved by means of an active laser radar, supporting consistent range and reflectance images. The laser radar developed at Zoller + Froehlich (ZF) is an optical-wavelength system measuring the range between sensor and target surface as well as the reflectance of the target surface, which corresponds to the magnitude of the back scattered laser energy. In contrast to other range sensing devices, the ZF system is designed for high-speed and high- performance operation in real indoor and outdoor environments, emitting a minimum of near-IR laser energy. It integrates a single-point laser measurement system and a mechanical deflection system for 3D environmental measurements. This paper reports details of the laser radar which is designed to cover requirements with medium range applications. It outlines the performance requirements and introduces the two-frequency phase-shift measurement principle. The hardware design of the single-point laser measurement system, including the main modulates, such as the laser head, the high frequency unit and the signal processing unit are discussed in detail. The paper focuses on performance data of the laser radar, including noise, drift over time, precision, and accuracy with measurements. It discusses the influences of ambient light, surface material of the target, and ambient temperature for range accuracy and range precision. Furthermore, experimental results from inspection of tunnels, buildings, monuments and industrial environments are presented. The paper concludes by summarizing results and gives a short outlook to future work.

  13. Synthetic aperture radar target detection, feature extraction, and image formation techniques

    NASA Technical Reports Server (NTRS)

    Li, Jian

    1994-01-01

    This report presents new algorithms for target detection, feature extraction, and image formation with the synthetic aperture radar (SAR) technology. For target detection, we consider target detection with SAR and coherent subtraction. We also study how the image false alarm rates are related to the target template false alarm rates when target templates are used for target detection. For feature extraction from SAR images, we present a computationally efficient eigenstructure-based 2D-MODE algorithm for two-dimensional frequency estimation. For SAR image formation, we present a robust parametric data model for estimating high resolution range signatures of radar targets and for forming high resolution SAR images.

  14. Through-wall imaging and characterization of human activity using ultrawideband (UWB) random noise radar

    NASA Astrophysics Data System (ADS)

    Lai, Chieh-Ping; Narayanan, Ram M.

    2005-05-01

    Recent terrorist activities and law-enforcement situations involving hostage situations underscore the need for effective through-wall imaging. Current building interior imaging systems are based on short-pulse waveforms, which require specially designed antennas to subdue unwanted ringing. In addition, periodically transmitted pulses of energy are easily recognizable by the intelligent adversary who may employ appropriate countermeasures to confound detection. A coherent polarimetric random noise radar architecture is being developed based on UWB technology and software defined radio, which has great promise in its ability to covertly image obscured targets. The main advantages of the random noise radar lie in two aspects: first, random noise waveform has an ideal "thumbtack" ambiguity function, i.e., its down range and cross range resolution can be separately controlled, thus providing unambiguous high resolution imaging at any distance; second, random noise waveform is inherently low probability of intercept (LPI) and low probability of detection (LPD), i.e., it is immune from detection, jamming, and interference. Thus, it is an ideal candidate sensor for covert imaging of obscured regions in hostile environments. The coherency in the system can be exploited to field a fully-polarimetric system that can take advantage of polarization features in target recognition. Moving personnel can also be detected using Doppler processing. Simulation studies are used to analyze backscattered signals from the walls, and humans and other targets behind the walls. Real-time data processing shows human activity behind the wall and human target tracking. The high resolution provides excellent multipath and clutter rejection.

  15. A fast level set method for synthetic aperture radar ocean image segmentation.

    PubMed

    Huang, Xiaoxia; Huang, Bo; Li, Hongga

    2009-01-01

    Segmentation of high noise imagery like Synthetic Aperture Radar (SAR) images is still one of the most challenging tasks in image processing. While level set, a novel approach based on the analysis of the motion of an interface, can be used to address this challenge, the cell-based iterations may make the process of image segmentation remarkably slow, especially for large-size images. For this reason fast level set algorithms such as narrow band and fast marching have been attempted. Built upon these, this paper presents an improved fast level set method for SAR ocean image segmentation. This competent method is dependent on both the intensity driven speed and curvature flow that result in a stable and smooth boundary. Notably, it is optimized to track moving interfaces for keeping up with the point-wise boundary propagation using a single list and a method of fast up-wind scheme iteration. The list facilitates efficient insertion and deletion of pixels on the propagation front. Meanwhile, the local up-wind scheme is used to update the motion of the curvature front instead of solving partial differential equations. Experiments have been carried out on extraction of surface slick features from ERS-2 SAR images to substantiate the efficacy of the proposed fast level set method. PMID:22399940

  16. Radar data pre-processing for reliable rain field estimation

    NASA Astrophysics Data System (ADS)

    Daliakopoulos, Ioannis N.; Tsanis, Ioannis K.

    2010-05-01

    A comparative analysis of different pre-processing methods applied to radar data for the minimization of the uncertainty of the produced Z-R relationship is conducted. The study focuses on measurements from 3 ground precipitation stations which are located in close proximity to the Souda Bay C-Band radar in Crete, Greece. While precipitation and reflectivity measurements were both collected in almost synchronized 10 minute intervals, uncertainties related to timing issues are discussed and measurements are aggregated to various scales up to 12 hours. Reflectivity measurements are also transformed and resampled in space, from polar coordinates to regular grids of 500 to 5000m resolution. The tradeoffs of both spatial and temporal transformation are discussed. Data is also filtered for noise using simple thresholding, the Wiener filter and combinations of both methods. The effects of the three pre-processing procedures are studied with respect to the final fit of the data to acceptable Z-R equations for the generation of reliable precipitation fields.

  17. Image Processing System

    NASA Technical Reports Server (NTRS)

    1986-01-01

    Mallinckrodt Institute of Radiology (MIR) is using a digital image processing system which employs NASA-developed technology. MIR's computer system is the largest radiology system in the world. It is used in diagnostic imaging. Blood vessels are injected with x-ray dye, and the images which are produced indicate whether arteries are hardened or blocked. A computer program developed by Jet Propulsion Laboratory known as Mini-VICAR/IBIS was supplied to MIR by COSMIC. The program provides the basis for developing the computer imaging routines for data processing, contrast enhancement and picture display.

  18. Enhanced Feature Based Mosaicing Technique for Visually and Geometrically Degraded Airborne Synthetic Aperture Radar Images

    NASA Astrophysics Data System (ADS)

    Manikandan, S.; Vardhini, J. P.

    2015-11-01

    In airborne synthetic aperture radar (SAR), there was a major problem encountered in the area of image mosaic in the absence of platform information and sensor information (geocoding), when SAR is applied in large-scale scene and the platform faces large changes. In order to enhance real-time performance and robustness of image mosaic, enhancement based Speeded-Up Robust Features (SURF) mosaic method for airborne SAR is proposed in this paper. SURF is a novel scale-invariant and rotation-invariant feature. It is perfect in its high computation, speed and robustness. In this paper, When the SAR image is acquired, initially the image is enhanced by using local statistic techniques and SURF is applied for SAR image matching accord to its characteristic, and then acquires its invariant feature for matching. In the process of image matching, the nearest neighbor rule for initial matching is used, and the wrong points of the matches are removed through RANSAC fitting algorithm. The proposed algorithm is implemented in different SAR images with difference in scale change, rotation change and noise. The proposed algorithm is compared with other existing algorithms and the quantitative and qualitative measures are calculated and tabulated. The proposed algorithm is robust to changes and the threshold is varied accordingly to increase the matching rate more than 95 %.

  19. Spaceborne radar applications in geology. An introduction to imaging radar and application examples of ERS SAR in geology and geomorphology

    NASA Astrophysics Data System (ADS)

    Fletcher, Karen

    2005-12-01

    This document is intended for geologists who are interested in broadening their knowledge of interpretation of imaging radar data, but also addresses the general public for reference and information. It introduces imaging radar as it may be used by technicians and image interpreters, stressing the use of synthetic aperture radar (SAR) for Earth observation in general and for geology in particular. Interferometric SAR is briefly treated, with some basic and practical hints. An illustrated application study on land subsidence is included. SAR/optical data fusion is explained, with examples of the different methods suggested. The main part of the document, part II, consists of 14 case studies that demonstrate the potential of SAR imagery for geology. These studies cover themes such as the detection and mapping of neotectonic activity, tectonic mapping, and recognition of karst structures, as well as analysis of active lahars and other volcanic events. They look into drainage systems in desert areas, consider lithofacies changes and morphostructure texture analysis, and they demonstrate the geological mapping of active tectonic compression. Finally, the document mentions the key points of the ESA SAR missions. Contacts for further information are also provided.

  20. Forward Looking Radar Imaging by Truncated Singular Value Decomposition and Its Application for Adverse Weather Aircraft Landing

    PubMed Central

    Huang, Yulin; Zha, Yuebo; Wang, Yue; Yang, Jianyu

    2015-01-01

    The forward looking radar imaging task is a practical and challenging problem for adverse weather aircraft landing industry. Deconvolution method can realize the forward looking imaging but it often leads to the noise amplification in the radar image. In this paper, a forward looking radar imaging based on deconvolution method is presented for adverse weather aircraft landing. We first present the theoretical background of forward looking radar imaging task and its application for aircraft landing. Then, we convert the forward looking radar imaging task into a corresponding deconvolution problem, which is solved in the framework of algebraic theory using truncated singular decomposition method. The key issue regarding the selecting of the truncated parameter is addressed using generalized cross validation approach. Simulation and experimental results demonstrate that the proposed method is effective in achieving angular resolution enhancement with suppressing the noise amplification in forward looking radar imaging. PMID:26094627

  1. Drumlin fields and glaciated mountains - A contrast in geomorphic perception from Seasat radar images

    NASA Technical Reports Server (NTRS)

    Ford, J. P.

    1981-01-01

    Digitally correlated Seasat synthetic-aperture radar (SAR) images of the Alaska Range, Alaska, and the drumlin-drift belt in Ireland are analyzed for the perception and identification of geomorphic features. The two terrains display strongly contrasted types of glacial topography whose identification in each case is related to the geometry of the Seasat imaging radar. Identification of terrain shape and form is important within the caveats imposed by the intrinsic distortions on the radar images. Image texture serves coarsely to distinguish topography. Image tones are scene-dependent and do not uniquely identify specific targets. Extensive alignments of linear and curvilinear features provide some of the more important image information from which to make geologic interpretations in each case.

  2. Three-dimensional ground penetrating radar imaging using multi-frequency diffraction tomography

    SciTech Connect

    Mast, J.E.; Johansson, E.M.

    1994-11-15

    In this talk we present results from a three-dimensional image reconstruction algorithm for impulse radar operating in monostatic pule-echo mode. The application of interest to us is the nondestructive evaluation of civil structures such as bridge decks. We use a multi-frequency diffraction tomography imaging technique in which coherent backward propagations of the received reflected wavefield form a spatial image of the scattering interfaces within the region of interest. This imaging technique provides high-resolution range and azimuthal visualization of the subsurface region. We incorporate the ability to image in planarly layered conductive media and apply the algorithm to experimental data from an offset radar system in which the radar antenna is not directly coupled to the surface of the region. We present a rendering in three-dimensions of the resulting image data which provides high-detail visualization.

  3. Visualizing characteristics of ocean data collected during the Shuttle Imaging Radar-B experiment

    NASA Technical Reports Server (NTRS)

    Tilley, David G.

    1991-01-01

    Topographic measurements of sea surface elevation collected by the Surface Contour Radar (SCR) during NASA's Shuttle Imaging Radar (SIR-B) experiment are plotted as three dimensional surface plots to observe wave height variance along the track of a P-3 aircraft. Ocean wave spectra were computed from rotating altimeter measurements acquired by the Radar Ocean Wave Spectrometer (ROWS). Fourier power spectra computed from SIR-B synthetic aperture radar (SAR) images of the ocean are compared to ROWS surface wave spectra. Fourier inversion of SAR spectra, after subtraction of spectral noise and modeling of wave height modulation, yields topography similar to direct measurements made by SCR. Visual perspectives on the SCR and SAR ocean data are compared. Threshold distinctions between surface elevation and texture modulations of SAR data are considered within the context of a dynamic statistical model of rough surface scattering. The result of these endeavors is insight as to the physical mechanism governing the imaging of ocean waves with SAR.

  4. Estimation of Ground Surface Displacement from Microwave Radar Images by Using Phase-only Correlation

    E-print Network

    Takiguchi, Tetsuya

    to use satellite images in earthquake analysis has been performed. Especially, the observation through surface displacement accurately from microwave radar images captured before/after an earthquake and also is examined through the experiment using real satellite images. 1. Introduction In recent years, an attempt

  5. Evidence of hydrocarbon pollution in soil exploiting satellite optical and radar images

    NASA Astrophysics Data System (ADS)

    Monsivais-Huertero, A.; Galvan-Pineda, J.; Espinosa-Hernandez, A.; Jimenez-Escalona, J. C.; Ramos-Rodriguez, J. M.

    2013-05-01

    Oil spills are one of the most important sources of hydrocarbon pollution in soils of areas near centers of extraction, storage or transportation of petroleum products. These spills or leaks can occur arising from deficient maintenance of facilities or accidents. The effects of these spills can spread for kilometers affecting large areas. This has a strong impact on the local ecosystem disturbing the flora and fauna. In costal tourist areas, this type of contaminants represents significant health risks for visitors and therefore, economic losses for the place. For this reason, it is very important to know and identify the areas affected by this type of pollution in order to create action plans for remediation of the ecosystem. Due to the large land extensions that can cover such disasters, satellite images become a valuable tool because of their large spatial coverage. Nowadays, different satellite techniques have been developed to recognize land affected by the presence of hydrocarbons. In the optical spectrum, optical sensing imagery (e.g. Landsat, SPOT, MODIS, etc.) has been widely used. However, these techniques have the intrinsic limitation in scenes with vegetation cover. In contrast, techniques exploiting radar images are still rare. The type of signal that is detected by the radar provides information even in areas with vegetation cover. The radar signal interacts with the vegetation and soil collecting information about the dielectric properties of the soil. This study identifies zones of contaminated soil by using the synergy of optical and radar images. This site of study is located in Paraiso, Tabasco, in Southern Mexico (18°27'N 93°32'W). The region is composed of coastal and tropical forest ecosystems and includes the Port Dos Bocas. The Port Dos Bocas has its points of extractions 130m away from the coast. The annual activities report 10 millions of tons of hydrocarbons transported using around 5500 ships. The methodology presented in this paper includes field measurements collecting soil samples at depths of 0-30 cm and 30-60 cm, the implementation of an algorithm to exploit Landsat 5 and 7 images to identify polluted zones, and the implementation of an algorithm using Envisat ASAR and an incoherent scattering model to delineate the polluted soil. The laboratory analysis of the soil samples showed that in all cases the most contaminated region of the soil is the deeper layer (30-60 cm). The processing of the optical images identifies contaminated regions mainly for bare soils and short vegetation. For highly vegetated regions, the optical images do not detect the polluted soils because the wavelength of observation cannot penetrate vegetation. The radar algorithm indicates that the most contaminated zones showed the lowest backscattering coefficient in comparison to clean zones. Unlike optical images, the Envisat images allowed the identification of polluted zones even under high vegetation conditions.

  6. Shuttle imaging radar (SIR-B) investigations of the Canadian Shield - Summary report

    NASA Technical Reports Server (NTRS)

    Masuoka, P. M.; Lowman, P. D.; Blodget, H. W.; Garvin, J. B.; Graham, D.

    1989-01-01

    The objectives and results of two imaging-radar experiments carried on a Shuttle mission with the purpose of studying the structure of crustal province boundaries and the effects of illumination geometry are reviewed. The primary geological objectives as well as the secondary technique-oriented objective are outlined, along with digital processing techniques. The tectonic relationships of structural provinces are analyzed, and data pertaining to the Kapuskasing Structural Zone is discussed. Fracture patterns and diabase dike swarms are assessed. Focus is placed on the utilization of multiple look directions and incidence angles and on digital image-enhancement techniques such as linear contrast stretch, low-pass filter for speckle reduction, modified Moore-Waltz edge enhancement, and coregistration and display of multiple look azimuths.

  7. Feature-enhanced synthetic aperture radar image formation based on nonquadratic regularization.

    PubMed

    Cetin, M; Karl, W C

    2001-01-01

    We develop a method for the formation of spotlight-mode synthetic aperture radar (SAR) images with enhanced features. The approach is based on a regularized reconstruction of the scattering field which combines a tomographic model of the SAR observation process with prior information regarding the nature of the features of interest. Compared to conventional SAR techniques, the method we propose produces images with increased resolution, reduced sidelobes, reduced speckle and easier-to-segment regions. Our technique effectively deals with the complex-valued, random-phase nature of the underlying SAR reflectivities. An efficient and robust numerical solution is achieved through extensions of half-quadratic regularization methods to the complex-valued SAR problem. We demonstrate the performance of the method on synthetic and real SAR scenes. PMID:18249651

  8. Impact of frequency and polarization diversity on a terahertz radar's imaging performance

    NASA Astrophysics Data System (ADS)

    Cooper, Ken B.; Dengler, Robert J.; Llombart, Nuria

    2011-05-01

    The Jet Propulsion Laboratory's 675 GHz, 25 m standoff imaging radar can achieve >1 Hz real time frame rates over 40x40 cm fields of view for rapid detection of person-borne concealed weapons. In its normal mode of operation, the radar generates imagery based solely on the time-of-flight, or range, between the radar and target. With good clothing penetration at 675 GHz, a hidden object will be detectable as an anomaly in the range-to-surface profile of a subject. Here we report on results of two modifications in the radar system that were made to asses its performance using somewhat different detection approaches. First, the radar's operating frequency and bandwidth were cut in half, to 340 GHz and 13 GHz, where there potential system advantages include superior transmit power and clothing penetration, as well as a lower cost of components. In this case, we found that the twofold reduction in range and cross-range resolution sharply limited the quality of through-clothes imagery, although some improvement is observed for detection of large targets concealed by very thick clothing. The second radar modification tested involved operation in a fully polarimetric mode, where enhanced image contrast might occur between surfaces with different material or geometric characteristics. Results from these tests indicated that random speckle dominates polarimetric power imagery, making it an unattractive approach for contrast improvement. Taken together, the experiments described here underscore the primary importance of high resolution imaging in THz radar applications for concealed weapons detection.

  9. wradlib - an Open Source Library for Weather Radar Data Processing

    NASA Astrophysics Data System (ADS)

    Pfaff, Thomas; Heistermann, Maik; Jacobi, Stephan

    2014-05-01

    Even though weather radar holds great promise for the hydrological sciences, offering precipitation estimates with unrivaled spatial and temporal resolution, there are still problems impeding its widespread use, among which are: almost every radar data set comes with a different data format with public reading software being available only rarely. standard products as issued by the meteorological services often do not serve the needs of original research, having either too many or too few corrections applied. Especially when new correction methods are to be developed, researchers are often forced to start from scratch having to implement many corrections in addition to those they are actually interested in. many algorithms published in the literature cannot be recreated using the corresponding article only. Public codes, providing insight into the actual implementation and how an approach deals with possible exceptions are rare. the radial scanning setup of weather radar measurements produces additional challenges, when it comes to visualization or georeferencing of this type of data. Based on these experiences, and in the hope to spare others at least some of these tedious tasks, wradlib offers the results of the author's own efforts and a growing number of community-supplied methods. wradlib is designed as a Python library of functions and classes to assist users in their analysis of weather radar data. It provides solutions for all tasks along a typical processing chain leading from raw reflectivity data to corrected, georeferenced and possibly gauge adjusted quantitative precipitation estimates. There are modules for data input/output, data transformation including Z/R transformation, clutter identification, attenuation correction, dual polarization and differential phase processing, interpolation, georeferencing, compositing, gauge adjustment, verification and visualization. The interpreted nature of the Python programming language makes wradlib an ideal tool for interactive data exploration and analysis. Based on the powerful scientific python stack (numpy, scipy, matplotlib) and in parts augmented by functions compiled in C or Fortran, most routines are fast enough to also allow data intensive re-analyses or even real-time applications. From the organizational point of view, wradlib is intended to be community driven. To this end, the source code is made available using a distributed version control system (DVCS) with a publicly hosted repository. Code may be contributed using the fork/pull-request mechanism available to most modern DVCS. Mailing lists were set up to allow dedicated exchange among users and developers in order to fix problems and discuss new developments. Extensive documentation is a key feature of the library, and is available online at http://wradlib.bitbucket.org. It includes an individual function reference as well as examples, tutorials and recipes, showing how those routines can be combined to create complete processing workflows. This should allow new users to achieve results quickly, even without much prior experience with weather radar data.

  10. On the combined use of radar systems for multi-scale imaging of transport infrastructures

    NASA Astrophysics Data System (ADS)

    Catapano, I.; Bavusi, M.; Loperte, A.; Crocco, L.; Soldovieri, F.

    2012-04-01

    Ground Penetrating Radar (GPR) systems are worth to be considered as in situ non invasive diagnostic tools capable of assessing stability and integrity of transport infrastructures. As a matter of fact, by exploiting the interactions among probing electromagnetic waves and hidden objects, they provide images of the inner status of the spatial region under test from which infer risk factors, such as deformations and oxidization of the reinforcement bars as well as water infiltrations, crack and air gaps. With respect to the assessment of concrete infrastructures integrity, the reconstruction capabilities of GPR systems have been widely investigated [1,2]. However, the demand for diagnostic tools capable of providing detailed and real time information motivates the design and the performance evaluation of novel technologies and data processing methodologies aimed not only to effectively detect hidden anomalies but also to estimate their geometrical features. In this framework, this communication aims at investigating the advantages offered by the joint use of two GPR systems both of them equipped with a specific tomographic imaging approach. The first considered system is a time domain GPR equipped with a 1.5GHz shielded antenna, which is suitable for quick and good resolution surveys of the shallower layers of the structure. As second system, the holographic radar Rascan-4/4000 [3,4] is taken into account, due to its capability of providing holograms of hidden targets from the amplitude of the interference signal arising between the backscattered field and a reference signal. The imaging capabilities of both the GPR tools are enhanced by means of model based data processing approaches, which afford the imaging as a linear inverse scattering problem. Mathematical details on the inversion strategies will be provided at the conference. The combined use of the above GPR systems allows to perform multi-resolution surveys of the region under test, whose aim is, first of all, to detect hidden anomalies and then to provide a high resolution image of their geometrical features. Therefore, reliable and efficient diagnostic surveys devoted to state the healthy state of a structure can be scheduled. Numerical examples and on field validations assessing the achievable reconstruction capabilities will be provided at the conference. [1] D. J. Daniels, Ground Penetrating Radar, in IEE Radar, Sonar and Navigation Series 15, London, U.K.: IEE, 2004. [2] M. Proto, M. Bavusi, R. Bernini et al., Transport Infrastructure Surveillance and Monitoring by Electromagnetic Sensing: The ISTIMES Project, Sensors, vol.10, n.12, pp.10620-10639, 2010. [3] S. Ivashov, I. A. Vasiliev, T. D. Bechtel, C. Snapp, Comparison between impulse and holographic subsurface radar for NDT of space vehicle structural materials, Progress In Electromagnetic Research, vol.3, pp.658-661, 2004. [4] I. Catapano. L. Crocco, A. F. Morabito, F. Soldovieri, Tomographic imaging of holographic GPR data for non-invasive structural assessment: the Musmeci Bridge investigation, submitted to Nondestructive Testing and Evaluation Acknowledgement The research leading to these results has received funding from the European Community's Seventh Framework Programme (FP7/2007-2013) under Grant Agreement no 225663.

  11. NASA Radar Images Asteroid Toutatis - Duration: 40 seconds.

    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...

  12. Sea surface wave reconstruction from marine radar images

    E-print Network

    Qi, Yusheng, S.M. Massachusetts Institute of Technology

    2012-01-01

    The X-band marine radar is one type of remote sensing technology which is being increasingly used to measure sea surface waves nowadays. In this thesis, how to reconstruct sea surface wave elevation maps from X-band marine ...

  13. Evaluation of multifrequency range-imaging technique implemented on the Chung-Li VHF atmospheric radar

    NASA Astrophysics Data System (ADS)

    Chen, J.-S.; Tsai, S.-C.; Su, C.-L.; Chu, Y.-H.

    2015-09-01

    Multifrequency range imaging technique (RIM) has been implemented on the Chung-Li VHF-array radar since 2008 after its renovation. This study made a more complete examination and evaluation of the RIM technique to facilitate the performance of the radar for atmospheric studies. Various experiments of RIM with different radar parameters such as pulse length, pulse shape, receiver bandwidth, transmitter frequency set, and so on, were conducted. The radar data employed for the study were collected from 2008 to 2013. It has been shown that two factors, the range/time delay of the signal traveling in the media and the standard deviation of Gaussian-shaped range-weighting function, play crucial roles in ameliorating the RIM-produced brightness (or power distribution); the two factors are associated with some radar parameters. In addition to radar parameters, long-term RIM data show that the aging of cable lines or key components of the radar system may result in an increase of the range/time delay of signal. It is also found that the range/time delay was visibly different for the echoes from the atmosphere with and without the presence of significant precipitation. A procedure of point-by-point correction of range/time delay was thus conducted to minimize the bogus brightness discontinuity at range gate boundaries. With the RIM technique, the Chung-Li VHF radar demonstrates its first successful observation of double-layer structures as well as their temporal and spatial variations with time.

  14. Adaptive Space/Frequency Processing for Distributed Aperture Radars Raviraj Advea

    E-print Network

    Adve, Raviraj

    Adaptive Space/Frequency Processing for Distributed Aperture Radars Raviraj Advea , Richard investigation into space-time-waveform adaptive processing for waveform diverse distributed apertures. The large the resolution of a monolithic system (single large radar) with the same power-aperture. This capability comes

  15. Acoustic micro-Doppler radar for human gait imaging.

    PubMed

    Zhang, Zhaonian; Pouliquen, Philippe O; Waxman, Allen; Andreou, Andreas G

    2007-03-01

    A portable acoustic micro-Doppler radar system for the acquisition of human gait signatures in indoor and outdoor environments is reported. Signals from an accelerometer attached to the leg support the identification of the components in the measured micro-Doppler signature. The acoustic micro-Doppler system described in this paper is simpler and offers advantages over the widely used electromagnetic wave micro-Doppler radars. PMID:17407918

  16. Shuttle Imaging Radar-A (SIR-A) experiment

    NASA Technical Reports Server (NTRS)

    Elachi, C. (editor); Cimino, J. B. (editor)

    1982-01-01

    The SIR-A experiment was conducted in order to acquire radar data over a variety of regions to further understanding of the radar signatures of various geologic features. The capability of the Shuttle as a scientific platform for observation of the Earth's resources was assessed. The SIR-A sensor operated nominally and the full data acquisition capacity of the optical recorder was used.

  17. 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.

  18. Informational Analysis for Compressive Sampling in Radar Imaging

    PubMed Central

    Zhang, Jingxiong; Yang, Ke

    2015-01-01

    Compressive sampling or compressed sensing (CS) works on the assumption of the sparsity or compressibility of the underlying signal, relies on the trans-informational capability of the measurement matrix employed and the resultant measurements, operates with optimization-based algorithms for signal reconstruction and is thus able to complete data compression, while acquiring data, leading to sub-Nyquist sampling strategies that promote efficiency in data acquisition, while ensuring certain accuracy criteria. Information theory provides a framework complementary to classic CS theory for analyzing information mechanisms and for determining the necessary number of measurements in a CS environment, such as CS-radar, a radar sensor conceptualized or designed with CS principles and techniques. Despite increasing awareness of information-theoretic perspectives on CS-radar, reported research has been rare. This paper seeks to bridge the gap in the interdisciplinary area of CS, radar and information theory by analyzing information flows in CS-radar from sparse scenes to measurements and determining sub-Nyquist sampling rates necessary for scene reconstruction within certain distortion thresholds, given differing scene sparsity and average per-sample signal-to-noise ratios (SNRs). Simulated studies were performed to complement and validate the information-theoretic analysis. The combined strategy proposed in this paper is valuable for information-theoretic orientated CS-radar system analysis and performance evaluation. PMID:25811226

  19. Informational analysis for compressive sampling in radar imaging.

    PubMed

    Zhang, Jingxiong; Yang, Ke

    2015-01-01

    Compressive sampling or compressed sensing (CS) works on the assumption of the sparsity or compressibility of the underlying signal, relies on the trans-informational capability of the measurement matrix employed and the resultant measurements, operates with optimization-based algorithms for signal reconstruction and is thus able to complete data compression, while acquiring data, leading to sub-Nyquist sampling strategies that promote efficiency in data acquisition, while ensuring certain accuracy criteria. Information theory provides a framework complementary to classic CS theory for analyzing information mechanisms and for determining the necessary number of measurements in a CS environment, such as CS-radar, a radar sensor conceptualized or designed with CS principles and techniques. Despite increasing awareness of information-theoretic perspectives on CS-radar, reported research has been rare. This paper seeks to bridge the gap in the interdisciplinary area of CS, radar and information theory by analyzing information flows in CS-radar from sparse scenes to measurements and determining sub-Nyquist sampling rates necessary for scene reconstruction within certain distortion thresholds, given differing scene sparsity and average per-sample signal-to-noise ratios (SNRs). Simulated studies were performed to complement and validate the information-theoretic analysis. The combined strategy proposed in this paper is valuable for information-theoretic orientated CS-radar system analysis and performance evaluation. PMID:25811226

  20. Analysis of the Gran Desierto, Pinacte Region, Sonora, Mexico, via shuttle imaging radar

    NASA Technical Reports Server (NTRS)

    Greeley, R.; Christensen, P. R.; Mchone, J. F.; Asmerom, Y.; Zimbelman, J. R.

    1984-01-01

    The radar discriminability of geolian features and their geological setting as imaged by the SIR-A experiment is examined. The Gran Desierto and Pincate volcanio field of Sonora, Mexico was used to analyze the radar characteristics of the interplay of aeolian features and volcano terrain. The area in the Gran Desierto covers 4000 sq. km. and contains sand dunes of several forms. The Pincate volcanio field covers more than 2.000 sq. km. and consists primarily of basaltic lavas. Margins of the field, especially on the western and northern sides, include several maar and maar-like craters; thus obtaining information on their radar characteristics for comparison with impact craters.

  1. SUBMITTED TO IEEE SPM SPECIAL ISSUE ON RECENT ADVANCES IN SAR IMAGING 1 Sparsity-Driven Synthetic Aperture Radar

    E-print Network

    Yanikoglu, Berrin

    Aperture Radar Imaging M¨ujdat C¸ etin, Ivana Stojanovi´c, N. ¨Ozben ¨Onhon, Kush R. Varshney, Sadegh on sparsity-driven synthetic aperture radar (SAR) imaging. In particular, it reviews (i) analysis and synthesis-based sparse signal representation formulations for SAR image formation together

  2. Thermal-wave radar: a novel subsurface imaging modality with extended depth-resolution dynamic range.

    PubMed

    Tabatabaei, Nima; Mandelis, Andreas

    2009-03-01

    Combining the ideas behind linear frequency modulated continuous wave radars and frequency domain photothermal radiometry (PTR), a novel PTR method is introduced. Analytical solutions to the heat diffusion problem for both opaque and transparent solids are provided. Simulations and experimental results suggest a significant improvement in the dynamic range when using the thermal-wave radar (TWR) instead of conventional PTR. A practical TWR image resolution augmentation method is proposed. PMID:19334943

  3. Thermal-wave radar: A novel subsurface imaging modality with extended depth-resolution dynamic range

    NASA Astrophysics Data System (ADS)

    Tabatabaei, Nima; Mandelis, Andreas

    2009-03-01

    Combining the ideas behind linear frequency modulated continuous wave radars and frequency domain photothermal radiometry (PTR), a novel PTR method is introduced. Analytical solutions to the heat diffusion problem for both opaque and transparent solids are provided. Simulations and experimental results suggest a significant improvement in the dynamic range when using the thermal-wave radar (TWR) instead of conventional PTR. A practical TWR image resolution augmentation method is proposed.

  4. A comparative study of algorithms for radar imaging from gapped data

    NASA Astrophysics Data System (ADS)

    Xu, Xiaojian; Luan, Ruixue; Jia, Li; Huang, Ying

    2007-09-01

    In ultra wideband (UWB) radar imagery, there are often cases where the radar's operating bandwidth is interrupted due to various reasons, either periodically or randomly. Such interruption produces phase history data gaps, which in turn result in artifacts in the image if conventional image reconstruction techniques are used. The higher level artifacts severely degrade the radar images. In this work, several novel techniques for artifacts suppression in gapped data imaging were discussed. These include: (1) A maximum entropy based gap filling technique using a modified Burg algorithm (MEBGFT); (2) An alternative iteration deconvolution based on minimum entropy (AIDME) and its modified version, a hybrid max-min entropy procedure; (3) A windowed coherent CLEAN algorithm; and (4) Two-dimensional (2-D) periodically-gapped Capon (PG-Capon) and APES (PG-APES) algorithms. Performance of various techniques is comparatively studied.

  5. Space Shuttle Columbia views the world with imaging radar: The SIR-A experiment

    NASA Technical Reports Server (NTRS)

    Ford, J. P.; Cimino, J. B.; Elachi, C.

    1983-01-01

    Images acquired by the Shuttle Imaging Radar (SIR-A) in November 1981, demonstrate the capability of this microwave remote sensor system to perceive and map a wide range of different surface features around the Earth. A selection of 60 scenes displays this capability with respect to Earth resources - geology, hydrology, agriculture, forest cover, ocean surface features, and prominent man-made structures. The combined area covered by the scenes presented amounts to about 3% of the total acquired. Most of the SIR-A images are accompanied by a LANDSAT multispectral scanner (MSS) or SEASAT synthetic-aperture radar (SAR) image of the same scene for comparison. Differences between the SIR-A image and its companion LANDSAT or SEASAT image at each scene are related to the characteristics of the respective imaging systems, and to seasonal or other changes that occurred in the time interval between acquisition of the images.

  6. Directional ocean wave measurements in a coastal setting using a focused array imaging radar

    SciTech Connect

    Frasier, S.J.; Liu, Y.; Moller, D.; McIntosh, R.E.; Long, C.

    1995-03-01

    A unique focused array imaging Doppler radar was used to measure directional spectra of ocean surface waves in a nearshore experiment performed on the North Carolina Outer Banks. Radar images of the ocean surface`s Doppler velocity were used to generate two dimensional spectra of the radial component of the ocean surface velocity field. These are compared to simultaneous in-situ measurements made by a nearby array of submerged pressure sensors. Analysis of the resulting two-dimensional spectra include comparisons of dominant wave lengths, wave directions, and wave energy accounting for relative differences in water depth at the measurement locations. Limited estimates of the two-dimensional surface displacement spectrum are derived from the radar data. The radar measurements are analogous to those of interferometric synthetic aperture radars (INSAR), and the equivalent INSAR parameters are shown. The agreement between the remote and in-situ measurements suggests that an imaging Doppler radar is effective for these wave measurements at near grazing incidence angles.

  7. Multiscale Solar Image Processing

    NASA Astrophysics Data System (ADS)

    Young, C. B.; Byrne, J.; Ireland, J.; Gallagher, P. T.; McAteer, R. J.

    2006-12-01

    Wavelets have been very successfully used as a tool for noise reduction and general processing of images. Despite this, wavelets have inherent limitations with 2-D data. Wavelets are well suited for describing point singularities but much of the interesting information in images is described by edges, lines or curves. Newly developed multiscale transforms address some of these issues. The ridgelet transform takes the multiscale concept of wavelets but applies it to 1-D objects (lines) instead of 0-D objects (points). The curvelet transform likewise applies to multiscale curves. We present a preliminary study of the use of these new multiscale transforms with solar image data. These data include TRACE EUV images and LASCO coronagraph images.

  8. The browse file of NASA/JPL quick-look radar images from the Loch Linnhe 1989 experiment

    NASA Technical Reports Server (NTRS)

    Brown, Walter E., Jr. (editor)

    1989-01-01

    The Jet Propulsion Laboratory (JPL) Aircraft Synthetic Aperture Radar (AIRSAR) was deployed to Scotland to obtain radar imagery of ship wakes generated in Loch Linnhe. These observations were part of a joint US and UK experiment to study the internal waves generated by ships under partially controlled conditions. The AIRSAR was mounted on the NASA-Ames DC-8 aircraft. The data acquisition sequence consisted of 8 flights, each about 6 hours in duration, wherein 24 observations of the instrumented site were made on each flight. This Browse File provides the experimenters with a reference of the real time imagery (approximately 100 images) obtained on the 38-deg track. These radar images are copies of those obtained at the time of observation and show the general geometry of the ship wake features. To speed up processing during this flight, the images were all processed around zero Doppler, and thus azimuth ambiguities often occur when the drift angel (yaw) exceeded a few degrees. However, even with the various shortcomings, it is believed that the experimenter will find the Browse File useful in establishing a basis for further investigations.

  9. Photon-counting compressive sensing laser radar for 3D imaging.

    PubMed

    Howland, G A; Dixon, P B; Howell, J C

    2011-11-01

    We experimentally demonstrate a photon-counting, single-pixel, laser radar camera for 3D imaging where transverse spatial resolution is obtained through compressive sensing without scanning. We use this technique to image through partially obscuring objects, such as camouflage netting. Our implementation improves upon pixel-array based designs with a compact, resource-efficient design and highly scalable resolution. PMID:22086015

  10. 60GHz Mobile Imaging Radar Yibo Zhu, Yanzi Zhu, Zengbin Zhang, Ben Y. Zhao, Haitao Zheng

    E-print Network

    California at Santa Barbara, University of

    .g. a mobile imaging radar system that captures the position, shape and surface material of nearby objects]. These constraints dramatically reduce the set of possible solu- tions. Traditional imaging systems rely on visible of lighting con- ditions under most indoor or outdoor conditions. Finally, 60GHz radios are relatively

  11. On the convergence of the phase gradient autofocus algorithm for synthetic aperture radar imaging

    SciTech Connect

    Hicks, M.J.

    1996-01-01

    Synthetic Aperture Radar (SAR) imaging is a class of coherent range and Doppler signal processing techniques applied to remote sensing. The aperture is synthesized by recording and processing coherent signals at known positions along the flight path. Demands for greater image resolution put an extreme burden on requirements for inertial measurement units that are used to maintain accurate pulse-to-pulse position information. The recently developed Phase Gradient Autofocus algorithm relieves this burden by taking a data-driven digital signal processing approach to estimating the range-invariant phase aberrations due to either uncompensated motions of the SAR platform or to atmospheric turbulence. Although the performance of this four-step algorithm has been demonstrated, its convergence has not been modeled mathematically. A new sensitivity study of algorithm performance is a necessary step towards this model. Insights that are significant to the application of this algorithm to both SAR and to other coherent imaging applications are developed. New details on algorithm implementation identify an easily avoided biased phase estimate. A new algorithm for defining support of the point spread function is proposed, which promises to reduce the number of iterations required even for rural scenes with low signal-to-clutter ratios.

  12. Signal processing for airborne doppler radar detection of hazardous wind shear as applied to NASA 1991 radar flight experiment data

    NASA Technical Reports Server (NTRS)

    Baxa, Ernest G., Jr.

    1992-01-01

    Radar data collected during the 1991 NASA flight tests have been selectively analyzed to support research directed at developing both improved as well as new algorithms for detecting hazardous low-altitude windshear. Analysis of aircraft attitude data from several flights indicated that platform stability bandwidths were small compared to the data rate bandwidths which should support an assumption that radar returns can be treated as short time stationary. Various approaches at detection of weather returns in the presence of ground clutter are being investigated. Non-coventional clutter rejection through spectrum mode tracking and classification algorithms is a subject of continuing research. Based upon autoregressive modeling of the radar return time sequence, this approach may offer an alternative to overcome errors in conventional pulse-pair estimates. Adaptive filtering is being evaluated as a means of rejecting clutter with emphasis on low signal-to-clutter ratio situations, particularly in the presence of discrete clutter interference. An analysis of out-of-range clutter returns is included to illustrate effects of ground clutter interference due to range aliasing for aircraft on final approach. Data are presented to indicate how aircraft groundspeed might be corrected from the radar data as well as point to an observed problem of groundspeed estimate bias variation with radar antenna scan angle. A description of how recorded clutter return data are mixed with simulated weather returns is included. This enables the researcher to run controlled experiments to test signal processing algorithms. In the summary research efforts involving improved modelling of radar ground clutter returns and a Bayesian approach at hazard factor estimation are mentioned.

  13. Integration of speckle de-noising and image segmentation using Synthetic Aperture Radar image for flood extent extraction

    NASA Astrophysics Data System (ADS)

    Senthilnath, J.; Shenoy, H. Vikram; Rajendra, Ritwik; Omkar, S. N.; Mani, V.; Diwakar, P. G.

    2013-06-01

    Flood is one of the detrimental hydro-meteorological threats to mankind. This compels very efficient flood assessment models. In this paper, we propose remote sensing based flood assessment using Synthetic Aperture Radar (SAR) image because of its imperviousness to unfavourable weather conditions. However, they suffer from the speckle noise. Hence, the processing of SAR image is applied in two stages: speckle removal filters and image segmentation methods for flood mapping. The speckle noise has been reduced with the help of Lee, Frost and Gamma MAP filters. A performance comparison of these speckle removal filters is presented. From the results obtained, we deduce that the Gamma MAP is reliable. The selected Gamma MAP filtered image is segmented using Gray Level Co-occurrence Matrix (GLCM) and Mean Shift Segmentation (MSS). The GLCM is a texture analysis method that separates the image pixels into water and non-water groups based on their spectral feature whereas MSS is a gradient ascent method, here segmentation is carried out using spectral and spatial information. As test case, Kosi river flood is considered in our study. From the segmentation result of both these methods are comprehensively analysed and concluded that the MSS is efficient for flood mapping.

  14. Quantum image processing?

    E-print Network

    Mario Mastriani

    2015-12-03

    This paper presents a number of problems concerning the practical (real) implementation of the techniques known as Quantum Image Processing. The most serious problem is the recovery of the outcomes after the quantum measurement, which will be demonstrated in this work that is equivalent to a noise measurement, and it is not considered in the literature on the subject. It is noteworthy that this is due to several factors: 1) a classical algorithm that uses Dirac's notation and then it is coded in MATLAB does not constitute a quantum algorithm, 2) the literature emphasizes the internal representation of the image but says nothing about the classical-to-quantum and quantum-to-classical interfaces and how these are affected by decoherence, 3) the literature does not mention how to implement in a practical way (at the laboratory) these proposals internal representations, 4) given that Quantum Image Processing works with generic qubits this requires measurements in all axes of the Bloch sphere, logically, and 5) among others. In return, the technique known as Quantum Boolean Image Processing is mentioned, which works with computational basis states (CBS), exclusively. This methodology allows us to avoid the problem of quantum measurement, which alters the results of the measured except in the case of CBS. Said so far is extended to quantum algorithms outside image processing too.

  15. HERMES: a high-speed radar imaging system for inspection of bridge decks

    SciTech Connect

    Azevedo, S.G.

    1996-10-26

    Corrosion of rebar in concrete bridges causes subsurface cracks and is a major cause of structural degradation that necessitates repair or replacement. Early detection of corrosion effects can limit the location and extent of necessary repairs, while providing long-term information about the infrastructure status. Most current detection methods, however, are destructive of the road surface and require closing or restricting traffic while the tests are performed. A ground-penetrating radar imaging system has been designed and developed that will perform the nondestructive evaluation of road-bed cracking at traffic speeds; i.e., without the need to restrict traffic flow. The first-generation system (called the HERMES bridge inspector), consists of an offset-linear array of 64 impulse radar transceivers and associated electronics housed in a trailer. Computers in the trailer and in the towing vehicle control the data acquisition, processing, and display. Cross-road resolution is three centimeters at up to 30 cm in depth, while down-road resolution depends on speed; 3 cm below 20 mph up to 8 cm at 50 mph. A two-meter- wide path is inspected on each pass over the roadway. This paper, describes the design of this system, shows preliminary results, and lays out its deployment schedule.

  16. Processing of High Resolution, Multiparametric Radar Data for the Airborne Dual-Frequency Precipitation Radar APR-2

    NASA Technical Reports Server (NTRS)

    Tanelli, Simone; Meagher, Jonathan P.; Durden, Stephen L.; Im, Eastwood

    2004-01-01

    Following the successful Precipitation Radar (PR) of the Tropical Rainfall Measuring Mission, a new airborne, 14/35 GHz rain profiling radar, known as Airborne Precipitation Radar - 2 (APR-2), has been developed as a prototype for an advanced, dual-frequency spaceborne radar for a future spaceborne precipitation measurement mission. . This airborne instrument is capable of making simultaneous measurements of rainfall parameters, including co-pol and cross-pol rain reflectivities and vertical Doppler velocities, at 14 and 35 GHz. furthermore, it also features several advanced technologies for performance improvement, including real-time data processing, low-sidelobe dual-frequency pulse compression, and dual-frequency scanning antenna. Since August 2001, APR-2 has been deployed on the NASA P3 and DC8 aircrafts in four experiments including CAMEX-4 and the Wakasa Bay Experiment. Raw radar data are first processed to obtain reflectivity, LDR (linear depolarization ratio), and Doppler velocity measurements. The dataset is then processed iteratively to accurately estimate the true aircraft navigation parameters and to classify the surface return. These intermediate products are then used to refine reflectivity and LDR calibrations (by analyzing clear air ocean surface returns), and to correct Doppler measurements for the aircraft motion. Finally, the the melting layer of precipitation is detected and its boundaries and characteristics are identifIed at the APR-2 range resolution of 30m. The resulting 3D dataset will be used for validation of other airborne and spaceborne instruments, development of multiparametric rain/snow retrieval algorithms and melting layer characterization and statistics.

  17. Synthetic Aperture Radar Processing by a Multiple Scale Neural System for Boundary and Surface

    E-print Network

    Grossberg, Stephen

    Synthetic Aperture Radar Processing by a Multiple Scale Neural System for Boundary and Surface Representation Stephen Grossberg 1 , Ennio Mingolla 2 , and James Williamson 3 Department of Cognitive and Neural containing range data gathered by a synthetic aperture radar (SAR) sensor. The boundary and surface

  18. Radar Signal Processing with Antenna Arrays via Maximum Likelihood* A. Lee Swindlehurst Petre Stoica

    E-print Network

    Swindlehurst, A. Lee

    Radar Signal Processing with Antenna Arrays via Maximum Likelihood* A. Lee Swindlehurst Petre 84602 USA swindle@ee.byu.edu Abstract This paper considers two different models for coherent radar data in which a single target is observed by an array of antennas in the presence of noise, clutter, and jamming

  19. Effects of Signal Processing and Antenna Frequency on the Geostatistical Structure of Ground-Penetrating Radar Data

    E-print Network

    Barrash, Warren

    -Penetrating Radar Data Greg A. Oldenborger1 , Michael D. Knoll and Warren Barrash Center for Geophysical suggested that the geostatistical structure of ground-penetrating radar data may be representative of the spatial structure of hydraulic properties. However, radar images of the subsurface can change drastically

  20. Three radar imaging methods based on the one-dimensional laser range profile

    NASA Astrophysics Data System (ADS)

    Mou, Yuan; Wu, Zhen-sen; Qu, Tan; Liao, Run-gui

    2013-09-01

    One-dimensional range profile is known as a simple radar imaging technology. Based on the imaging mechanism, the laser range profiles (LRPS) of the convex rotators in three different methods, which named as the Beam Scattering Method (BS method), Radar Cross Section Method (RCS method) and Surface Elements Method (SE method),were studied. In detail, BS method, which combined the laser beam pulse scattering theory and radar equation, is the very model that can be applied to the convex quadric rotary bodies, however, it may produce singular solutions in certain incident directions. The RCS method is just an extension of the theory of radar cross section theory and radar equation. According to the definition, the simplest forms of RCS which were then substituted into the radar equation were obtained, finally the one-dimensional range profiles were analytically resolved. The SE Method is a much more comprehensive theory to get the laser range profiles of arbitrary objects. The object should be first divided into numerous small triangle facets, and sum the backscattering power of these facets in the same distance, and in this way the final LRPS were deduced. In the meanwhile, the SE method is the most convenient way to evolve into the three-dimensional range profile. In the paper, the LRPS of a cone based on the three models above were simulated, it was found that the features and shape of each profiles were similar basically, but theoretical correction to SE method was still needed.

  1. Radar Imaging of Binary Near-Earth Asteroid (357439) 2004 BL86

    NASA Astrophysics Data System (ADS)

    Benner, Lance AM; Brozovic, Marina; Giorgini, Jon D.; Jao, Joseph S.; Lee, Clement G.; Taylor, Patrick A.; Howell, Ellen S.; Busch, Michael W.; Ford, H. Alyson; Ghigo, Frank; Nolan, Michael C.; Slade, Martin A.; Lawrence, Kenneth J.; Richardson, James E.; Rivera-Valentin, Edgard G.; Rozek, Agata

    2015-08-01

    We report radar observations of near-Earth asteroid 2004 BL86 obtained during 2015 Jan. 26-31 at the 70 m and 34 m Goldstone facilities, Arecibo, Green Bank, and elements of the Very Long Baseline Array. 2004 BL86 approached within 0.0080 au (3.1 lunar distances) on Jan. 26, the closest known approach by any object with an absolute magnitude brighter than ~19 until 2027. Prior to the encounter, virtually nothing was known about its physical properties other than its absolute magnitude of 19, which suggested a diameter within a factor of two of 500 m. Due to its size and the extremely close approach, 2004 BL86 was a very strong radar target that provided an outstanding opportunity for radar imaging and physical characterization. The radar images confirmed photometric results reported by Pravec et al. (2015, CBET 4063) that 2004 BL86 is a binary system. This is the 43rd near-Earth asteroid binary detected by radar. Delay-Doppler images placed thousands of 3.75 m-resolution pixels on the object and reveal a rounded and oblate primary with an equatorial diameter of ~300 m, suggesting it is optically-bright, evidence for ridges, small-scale topography including boulders, and a large angular feature near one of the poles. A preliminary estimate for the diameter of the secondary is ~70 m. The images hint that the secondary’s rotation is synchronous with its orbital period. The observations also yielded the first detection of an asteroid with a new 80 kW C-band radar (7190 MHz, 4.2 cm) at the 34 m DSS-13 antenna at the Goldstone Deep Space Communications Complex. This new radar can achieve a range resolution up to 1.875 m/pixel that is twice as fine as the highest resolution previously achievable.

  2. The detection of weak signal patterns in radar ocean intensity images

    SciTech Connect

    Manasse, R.

    1996-06-15

    Detection of weak patterns in radar ocean RCS images is complicated by the fact that signals and noise are interactive rather than additive and the ambient noise background is non Gaussian or even strongly non Gaussian at low grazing angles. This paper addresses this difficult problem with the aid of two simplifying assumptions: (1) the signal modulation is weak, and (2) departure from Gaussianity is small. In situations where this departure is large, an approach is suggested for reducing this non Gaussianity. The relevant weak signal detection theory, based on the Likelihood ratio, is reviewed and adapted for use in the analysis. The approach to this problem, similar to that previously used for complex images, is facilitated by approximating the multivariate probability distributions as a composite integral involving underlying processes which are assumed to be Gaussian. This formulation, subject to the approximations in the analysis, permits derivation of an ideal detection statistic (which determines the form of optimum receiver) and a signal/noise ratio which characterizes detection performance in the weak signal limit. Implications for image processing are discussed and directions for future analysis are suggested.

  3. Three-dimensional subsurface imaging Synthetic Aperture Radar

    SciTech Connect

    Wuenschel, E.

    1995-10-01

    This report describes the development of a system known as 3-D SISAR. This system consists of a ground penetrating radar with software algorithms designed for the detection, location, and identification of buried objects in the underground hazardous waste environments at DOE storage sites.

  4. Titan Electromagnetic Response and Surface Roughness Imaged by Cassini RADAR

    NASA Astrophysics Data System (ADS)

    Paganelli, F.; van Zyl, J.; Janssen, M. A.; Stiles, B.; West, R.; Lopes, R. M.; Stofan, E.; Callahan, P.; Roth, L.; Wall, S. D.; Farr, T. G.; Elachi, C.; Lorenz, R. D.; Soderblom, L.; Radar Team

    2006-03-01

    Cassini RADAR SAR data have been used to estimate the electromagnetic response and surface roughness as Root Mean Square (RMS). Estimates are derived using a modified empirical model developed from data of the LCX POLARSCAT, and RASAM systems of Earth observations.

  5. Processing Of Binary Images

    NASA Astrophysics Data System (ADS)

    Hou, H. S.

    1985-07-01

    An overview of the recent progress in the area of digital processing of binary images in the context of document processing is presented here. The topics covered include input scan, adaptive thresholding, halftoning, scaling and resolution conversion, data compression, character recognition, electronic mail, digital typography, and output scan. Emphasis has been placed on illustrating the basic principles rather than descriptions of a particular system. Recent technology advances and research in this field are also mentioned.

  6. Optimal Signal Processing of Frequency-Stepped CW Radar Data

    NASA Technical Reports Server (NTRS)

    Ybarra, Gary A.; Wu, Shawkang M.; Bilbro, Griff L.; Ardalan, Sasan H.; Hearn, Chase P.; Neece, Robert T.

    1995-01-01

    An optimal signal processing algorithm is derived for estimating the time delay and amplitude of each scatterer reflection using a frequency-stepped CW system. The channel is assumed to be composed of abrupt changes in the reflection coefficient profile. The optimization technique is intended to maximize the target range resolution achievable from any set of frequency-stepped CW radar measurements made in such an environment. The algorithm is composed of an iterative two-step procedure. First, the amplitudes of the echoes are optimized by solving an overdetermined least squares set of equations. Then, a nonlinear objective function is scanned in an organized fashion to find its global minimum. The result is a set of echo strengths and time delay estimates. Although this paper addresses the specific problem of resolving the time delay between the first two echoes, the derivation is general in the number of echoes. Performance of the optimization approach is illustrated using measured data obtained from an HP-X510 network analyzer. It is demonstrated that the optimization approach offers a significant resolution enhancement over the standard processing approach that employs an IFFT. Degradation in the performance of the algorithm due to suboptimal model order selection and the effects of additive white Gaussion noise are addressed.

  7. Optimal Signal Processing of Frequency-Stepped CW Radar Data

    NASA Technical Reports Server (NTRS)

    Ybarra, Gary A.; Wu, Shawkang M.; Bilbro, Griff L.; Ardalan, Sasan H.; Hearn, Chase P.; Neece, Robert T.

    1995-01-01

    An optimal signal processing algorithm is derived for estimating the time delay and amplitude of each scatterer reflection using a frequency-stepped CW system. The channel is assumed to be composed of abrupt changes in the reflection coefficient profile. The optimization technique is intended to maximize the target range resolution achievable from any set of frequency-stepped CW radar measurements made in such an environment. The algorithm is composed of an iterative two-step procedure. First, the amplitudes of the echoes are optimized by solving an overdetermined least squares set of equations. Then, a nonlinear objective function is scanned in an organized fashion to find its global minimum. The result is a set of echo strengths and time delay estimates. Although this paper addresses the specific problem of resolving the time delay between the two echoes, the derivation is general in the number of echoes. Performance of the optimization approach is illustrated using measured data obtained from an HP-851O network analyzer. It is demonstrated that the optimization approach offers a significant resolution enhancement over the standard processing approach that employs an IFFT. Degradation in the performance of the algorithm due to suboptimal model order selection and the effects of additive white Gaussion noise are addressed.

  8. Application of image processing to randomly rough surfaces

    NASA Astrophysics Data System (ADS)

    Zhang, Xiangdong; Wu, Chengke

    1997-10-01

    Ocean surfaces should be considered as randomly rough surfaces at the IR and optical bands. The geometric model of sea surfaces has been obtained by using image processing. Based on the electromagnetic scattering theory, the Laser Radar Cross Section for the sea surfaces is analyzed at IR band and the scattering properties of the sea surfaces have been gotten.

  9. Co-registration of ultrasound and frequency-domain photoacoustic radar images and image improvement for tumor detection

    NASA Astrophysics Data System (ADS)

    Dovlo, Edem; Lashkari, Bahman; Choi, Sung soo Sean; Mandelis, Andreas

    2015-03-01

    This paper demonstrates the co-registration of ultrasound (US) and frequency domain photoacoustic radar (FD-PAR) images with significant image improvement from applying image normalization, filtering and amplification techniques. Achieving PA imaging functionality on a commercial Ultrasound instrument could accelerate clinical acceptance and use. Experimental results presented demonstrate live animal testing and show enhancements in signal-to-noise ratio (SNR), contrast and spatial resolution. The co-registered image produced from the US and phase PA images, provides more information than both images independently.

  10. Image-Processing Program

    NASA Technical Reports Server (NTRS)

    Roth, D. J.; Hull, D. R.

    1994-01-01

    IMAGEP manipulates digital image data to effect various processing, analysis, and enhancement functions. It is keyboard-driven program organized into nine subroutines. Within subroutines are sub-subroutines also selected via keyboard. Algorithm has possible scientific, industrial, and biomedical applications in study of flows in materials, analysis of steels and ores, and pathology, respectively.

  11. Image Processing for Teaching.

    ERIC Educational Resources Information Center

    Greenberg, R.; And Others

    1993-01-01

    The Image Processing for Teaching project provides a powerful medium to excite students about science and mathematics, especially children from minority groups and others whose needs have not been met by traditional teaching. Using professional-quality software on microcomputers, students explore a variety of scientific data sets, including…

  12. Image processing and reconstruction

    SciTech Connect

    Chartrand, Rick

    2012-06-15

    This talk will examine some mathematical methods for image processing and the solution of underdetermined, linear inverse problems. The talk will have a tutorial flavor, mostly accessible to undergraduates, while still presenting research results. The primary approach is the use of optimization problems. We will find that relaxing the usual assumption of convexity will give us much better results.

  13. Near-Earth Asteroid 2005 CR37: Radar Images and Photometry of a Candidate Contact Binary

    NASA Technical Reports Server (NTRS)

    Benner, Lance A. M.; Nolan, Michael C.; Ostro, Steven J.; Giorgini, Jon D.; Pray, Donald P.; Harris, Alan W.; Magri, Christopher; Margot, Jean-Luc

    2006-01-01

    Arecibo (2380 MHz, 13 cm) radar observations of 2005 CR37 provide detailed images of a candidate contact binary: a 1.8-km-long, extremely bifurcated object. Although the asteroid's two lobes are round, there are regions of modest topographic relief, such as an elevated, 200-m-wide facet, that suggest that the lobes are geologically more complex than either coherent fragments or homogeneous rubble piles. Since January 1999, about 9% of NEAs larger than approx.200 m imaged by radar can be described as candidate contact binaries.

  14. A User-friendly System for Synthetic Aperture Radar Image Classi cation based on Grayscale Distributional Properties and Context

    E-print Network

    de Figueiredo, Luiz Henrique

    A User-friendly System for Synthetic Aperture Radar Image Classi cation based on Grayscale Aperture Radar SAR images. This system, unlike most of its competitors, allows a careful modeling Distributional Properties and Context Alejandro C. Frery1 Corina da C. F. Yanasse2 Pedro R. Vieira3 Sidnei J. S

  15. THE APPLICATION OF ACTIVE CONTOURS FOR THE LOCALIZATION OF VARYING-CONTRAST EDGES IN SYNTHETIC APERTURE RADAR IMAGES

    E-print Network

    Hamburg,.Universität

    APERTURE RADAR IMAGES Benjamin Seppke and Leonie Dreschler-Fischer University of Hamburg, MIN-Faculty, Department of Informatics, Cognitive Systems Laboratory Vogt-Kölln-Str 30 D-22527 Hamburg Germany Email applying the basic snake technique to synthetic aperture radar (SAR) remote sensing images

  16. Automatic target classification of man-made objects in synthetic aperture radar images using Gabor wavelet and neural network

    NASA Astrophysics Data System (ADS)

    Vasuki, Perumal; Roomi, S. Mohamed Mansoor

    2013-01-01

    Processing of synthetic aperture radar (SAR) images has led to the development of automatic target classification approaches. These approaches help to classify individual and mass military ground vehicles. This work aims to develop an automatic target classification technique to classify military targets like truck/tank/armored car/cannon/bulldozer. The proposed method consists of three stages via preprocessing, feature extraction, and neural network (NN). The first stage removes speckle noise in a SAR image by the identified frost filter and enhances the image by histogram equalization. The second stage uses a Gabor wavelet to extract the image features. The third stage classifies the target by an NN classifier using image features. The proposed work performs better than its counterparts, like K-nearest neighbor (KNN). The proposed work performs better on databases like moving and stationary target acquisition and recognition against the earlier methods by KNN.

  17. Imaging Buried Culverts Using Ground Penetrating Radar: Comparing 100 MHZ Through 1 GHZ Antennae

    NASA Astrophysics Data System (ADS)

    Abdul Aziz, A.; Stewart, R. R.; Green, S. L.

    2013-12-01

    *Aziz, A A aabdulaziz@uh.edu Allied Geophysical Lab, Department of Earth and Atmospheric Sciences, University of Houston, TX, USA Stewart, R R rrstewart@uh.edu Allied Geophysical Lab, Department of Earth and Atmospheric Sciences, University of Houston, TX, USA *Green, S L slgreen@yahoo.com Allied Geophysical Lab, Department of Earth and Atmospheric Sciences, University of Houston, TX, USA A 3D ground penetrating radar (GPR) survey, using three different frequency antennae, was undertaken to image buried steel culverts at the University of Houston's La Marque Geophysical Observatory 30 miles south of Houston, Texas. The four culverts, under study, support a road crossing one of the area's bayous. A 32 m by 4.5 m survey grid was designed on the road above the culverts and data were collected with 100 MHz, 250 MHz, and 1 GHz antennae. We used an orthogonal acquisition geometry for the three surveys. Inline sampling was from 1.0 cm to 10 cm (from 1 GHz to 100 MHz antenna) with inline and crossline spacings ranging from 0.2 m to 0.5 m. We used an initial velocity of 0.1 m/ns (from previous CMP work at the site) for the display purposes. The main objective of the study was to analyze the effect of different frequency antennae on the resultant GPR images. We are also interested in the accuracy and resolution of the various images, in addition to developing an optimal processing flow.The data were initially processed with standard steps that included gain enhancement, dewow and temporal-filtering, background suppression, and 2D migration. Various radar velocities were used in the 2D migration and ultimately 0.12 m/ns was used. The data are complicated by multipathing from the surface and between culverts (from modeling). Some of this is ameliorated via deconvolution. The top of each of the four culverts was evident in the GPR images acquired with the 250 MHz and 100 MHz antennas. For 1 GHz, the top of the culvert was not clear due to the signal's attenuation. The 250 MHz shielded antenna provides a vertical resolution of about 0.1 m and is the choice to image the culverts. The 100 MHz antenna provided an increment in depth of penetration, but at the expense of a substantially diminished resolution (0.25 m).

  18. Information extraction and transmission techniques for spaceborne synthetic aperture radar images

    NASA Technical Reports Server (NTRS)

    Frost, V. S.; Yurovsky, L.; Watson, E.; Townsend, K.; Gardner, S.; Boberg, D.; Watson, J.; Minden, G. J.; Shanmugan, K. S.

    1984-01-01

    Information extraction and transmission techniques for synthetic aperture radar (SAR) imagery were investigated. Four interrelated problems were addressed. An optimal tonal SAR image classification algorithm was developed and evaluated. A data compression technique was developed for SAR imagery which is simple and provides a 5:1 compression with acceptable image quality. An optimal textural edge detector was developed. Several SAR image enhancement algorithms have been proposed. The effectiveness of each algorithm was compared quantitatively.

  19. SHUTTLE IMAGING RADAR: PHYSICAL CONTROLS ON SIGNAL PENETRATION AND SUBSURFACE SCATTERING IN THE EASTERN SAHARA.

    USGS Publications Warehouse

    Schaber, Gerald G.; McCauley, John F.; Breed, Carol S.; Olhoeft, Gary R.

    1986-01-01

    It is found that the Shuttle Imaging Radar A (SIR-A) signal penetration and subsurface backscatter within the upper meter or so of the sediment blanket in the Eastern Sahara of southern Egypt and northern Sudan are enhanced both by radar sensor parameters and by the physical and chemical characteristics of eolian and alluvial materials. The near-surface stratigraphy, the electrical properties of materials, and the types of radar interfaces found to be responsible for different classes of SIR-A tonal response are summarized. The dominant factors related to efficient microwave signal penetration into the sediment blanket include 1) favorable distribution of particle sizes, 2) extremely low moisture content and 3) reduced geometric scattering at the SIR-A frequency (1. 3 GHz). The depth of signal penetration that results in a recorded backscatter, called radar imaging depth, was documented in the field to be a maximum of 1. 5 m, or 0. 25 times the calculated skin depth, for the sediment blanket. The radar imaging depth is estimated to be between 2 and 3 m for active sand dune materials.

  20. A novel super-resolution imaging method based on stochastic radiation radar array

    NASA Astrophysics Data System (ADS)

    Guo, Yuanyue; He, Xuezhi; Wang, Dongjin

    2013-07-01

    A novel concept of stochastic radiation radar array (SRRA) is proposed to achieve super-resolution in real aperture staring radar imagery. Firstly, the definition of the temporal-spatial stochastic characteristics of the temporal-spatial stochastic radiation field (TSSRF) is presented. Then, a correlated imaging algorithm based on Gram-Schmidt orthogonalization (GSO-CIA) is proposed to reconstruct the target image using the echo signals and TSSRF. By the theoretical analysis, the super-resolution potentiality of staring imaging based on stochastic radiation radar array (SRRA-SI) is verified, which can overcome the resolution limitation of the real antenna aperture. The influences of the random transmitting signals and the configuration of the radar array (the number of array elements, the size array aperture, etc) on the stochastic characteristics of TSSRF are investigated in detail. Finally, numerical simulations are performed and the striking effect of super-resolution, which is more than 20 times compared with traditional real-aperture radar array, is demonstrated.

  1. The US Geological Survey's side-looking airborne radar acquisition program: Image data from the Rocky Mountains to the Pacific

    SciTech Connect

    Kovar, A.N.; Schoonmaker, J.W. Jr. )

    1993-04-01

    The US Geological Survey (USGS) has been systematically collecting side-looking airborne radar (SLAR) image data for the US since 1980. The image strip swaths, ranging in width from 20 to 46 km, are acquired commercially by X-band (3 cm) radar systems. Data are acquired with 60 percent side-lap for better mosaic preparation and stereoscopic capability. The image strips are assembled into 1[degree] x 2[degree] mosaic quadrangles that are based on the USGS 1:250,000-topographic map series for control, format, and nomenclature. These mosaics present the data in a broad synoptic view that facilitates geologic interpretation. SLAR image mosaics have been prepared for more than 35 percent of the US west of the Rocky Mountain front. In addition to quadrangle mosaics, regional composite mosaics have been prepared as value-added products. These include Pacific Northwest (14 quadrangles), southern California Coastal (from San Francisco to San Diego), Reno-Walker (includes parts of Yellowstone and Grand Teton National Parks), Uinta Basin (Salt Lake City, Price and Grand Junction), and Salton Sea Region (San Diego, Santa Ana, El Centro and Salton Sea). Most of the image data are available on computer compatible tapes and photographic products. To make the data more accessible and reasonably priced, the strip images are being processed into CD-ROM (compact disc, read-only memory). One demonstration CD-ROM includes the mosaics of Las Vegas, Mariposa, Ritzville, Walla Walla, and Pendleton quadrangles.

  2. Data Processing and Primary results of Lunar Penetrating Radar on Board the Chinese Yutu Rover

    NASA Astrophysics Data System (ADS)

    Su, Yan; Xing, Shuguo; Feng, Jianqing; Dai, Shun; Ding, Chunyu; Xiao, Yuan; Zhang, Hongbo; Zhao, Shu; Xue, Xiping; Zhang, Xiaoxia; Liu, Bin; Yao, Meijuan; Li, Chunlai

    2015-04-01

    Radar is an attractive and powerful technique to observe the Moon. Radar mapping of the Moon's topography was first done by the Arecibo telescope at a wave- length of 70 cm in 1964 (Thompson & Dyce 1966). Chang'e-3 (CE-3) was successfully launched on 2013 December 2, and the landing place is in Mare Imbrium, about 40km south of the 6km diameter Laplace F crater, at 44.1214ON, 19.5116OW. The Lunar ground-Penetrating Radar (LPR) is one of scientific payloads of the Yutu rover, aiming to achieve the first direct measurements and explore the lunar subsurface structure. Compared with ALSE and LRS, LPR works at higher frequencies of 60 MHz and 500 MHz. Thus it can probe regions with shallower depth including the regolith and lunar crust at higher range resolution. The LPR uses one transmitting and one receiving dipole antenna for 60 MHz which are installed at the back of the rover. For 500 MHz, one transmitting and two bow-tie receiving antennas are attached to the bottom of the rover. It transmits a pulsed signal and receives the radar echo signal along the path that the Yutu rover traverses. The free space range resolutions are ~ 50 cm and ~ 25 m for 60 MHz and 500 MHz respectively. The radar data stop being sampled and are sent back to Earth when Yutu is stationary. Observations are simultaneously carried out at frequencies of 60 MHz and 500 MHz. Since the Yutu rover had severe problems during its second lunar day, it is pity that the Yutu rover only transversed a limited distance of 114.8m. In total, 566 MB of data were obtained. The scientific data are archived and distributed by National Astronomical Observatories, Chinese Academy of Sciences. Data processing has been done in order to eliminate the effect of the instrument. To obtain clear radar images, more data processing need to be applied such as coordinate transformation, data editing, background removal, the operations of smoothing and gain resetting. The radar signal could detect hundreds of meters deep at 60MHz and tens of meters at 500MHz. Based on the previous lunar subsurface research and Apollo samples analysis, the dielectric constantÉ?r of the lunar rock is set to be 7 and the dielectric constantÉ?r of the lunar regolith is set to be 3.1 The LPR observations reveal that Mare Imbrium has subsurface stratifications. The regolith is not uniform and structures with multiple layers have been observed. The results indicate the thickness of the regolith is 4-6 m. The typical hyperbolic shapes that might be caused by rocks underneath the regolith have been found. Furthermore, several prominent reflective layers at depths of hundreds of meters have been clearly derived. The buried regolith layer might have been accumulated during the depositional hiatus of mare basalts.

  3. Onboard Radar Processing Development for Rapid Response Applications

    NASA Technical Reports Server (NTRS)

    Lou, Yunling; Chien, Steve; Clark, Duane; Doubleday, Josh; Muellerschoen, Ron; Wang, Charles C.

    2011-01-01

    We are developing onboard processor (OBP) technology to streamline data acquisition on-demand and explore the potential of the L-band SAR instrument onboard the proposed DESDynI mission and UAVSAR for rapid response applications. The technology would enable the observation and use of surface change data over rapidly evolving natural hazards, both as an aid to scientific understanding and to provide timely data to agencies responsible for the management and mitigation of natural disasters. We are adapting complex science algorithms for surface water extent to detect flooding, snow/water/ice classification to assist in transportation/ shipping forecasts, and repeat-pass change detection to detect disturbances. We are near completion of the development of a custom FPGA board to meet the specific memory and processing needs of L-band SAR processor algorithms and high speed interfaces to reformat and route raw radar data to/from the FPGA processor board. We have also developed a high fidelity Matlab model of the SAR processor that is modularized and parameterized for ease to prototype various SAR processor algorithms targeted for the FPGA. We will be testing the OBP and rapid response algorithms with UAVSAR data to determine the fidelity of the products.