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SYNTHETIC APERTURE RADAR

Subclass of:

342 - Communications: directive radio wave systems and devices (e.g., radar, radio navigation)

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Class / Patent application numberDescriptionNumber of patent applications / Date published
342025000 Mapping or imaging using synthetic aperture radar (EPO) 120
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DocumentTitleDate
20100045514DEVICE FOR IMAGING TEST OBJECTS USING ELECTROMAGNETIC WAVES, IN PARTICULAR FOR INSPECTING PEOPLE FOR SUSPICIOUS ITEMS - To depict test objects using electromagnetic waves, particularly to check people for suspicious articles, an apparatus is provided having: an antenna which emits electromagnetic waves, particularly millimetric waves, means for concentrating the emitted waves in three dimensions, and means for manipulating the waves at the point of high concentration such that this point serves as a moving virtual antenna for SAR evaluation. Whereby the means for three-dimensional concentration contain a rotatably mounted, focusing or defocusing, quasi-optical element and the means for manipulating the waves at the point of high concentration contain a reflector. In accordance with the invention, the quasi-optical element and the reflector are rotatably mounted about a common rotary axis and at the same angular velocity.02-25-2010
20090267825Method and Apparatus for Compressing SAR Signals - A method compresses synthetic aperture radar (SAR) data by sampling the SAR data into blocks and transforming each block to a corresponding block of transform coefficients. Each block of transform coefficient is quantized according to a quantization parameter to obtain a corresponding block of quantized transform coefficients, which are demultiplexed into sets of blocks of quantized transform coefficients. The quantized transform coefficients in the blocks in each set are arithmetically encoding in parallel according to a probability model to produce an intermediate bitstream for each set of blocks. The encoding of the quantized transform coefficients of one block is independent of the quantized transform coefficients of a successive block. The intermediate of bitstreams are then multiplexed to a compressed bitstream, which can be transmitted, or stored, for subsequent decoding to construct an SAR image.10-29-2009
20110215964RADAR APPARATUS AND TARGET DETECTING METHOD - Provided is a radar apparatus including an envelope detector unit that acquires an envelope component of a signal transmitted from a receiving antenna in at least one combination of a plurality of combinations of transmitting antennas and receiving antennas whose spatial phases become equal to each other in the array antenna; a determination unit that determines an amount of compensation in the at least one combination based on the envelope component acquired by the envelope detector unit; and a compensator unit that compensates a phase of a signal transmitted from each of the receiving antennas before aperture synthesis by using the amount of compensation determined by the determination unit, or compensates a phase of a signal radiated from the transmitting antenna in another combination.09-08-2011
20090085800Radar system and method of digital beamforming - A radar system and method is provided, in which the radar system includes a first transmitting portion of antenna elements, a second transmitting portion of antenna elements, and a receiving portion of antenna elements, such that the receiving antenna elements form a plurality of subarrays that represent real and synthetic antenna elements. The radar system further includes a transceiving device having a switching matrix. At least first and second switching transmit antenna elements are configured and time-multiplexed, wherein a receive aperture of the receiving antenna elements is increased. A first signal transmitted is received by the real antenna elements and a second signal transmitted is received by the real antenna elements, and combined so that the signals received from the first switching transmit antenna element represents a signal received by the real receive antenna element, and the signal received from the second switching transmit antenna element represents a signal received by the synthetic receive antenna element.04-02-2009
20090231185METHOD AND SYSTEM FOR MAPPING A TARGET SCENE USING SCANNING RADAR - A system and method for mapping a target scene by means of scanning radar utilizing the Doppler effect that arises in the event of movement between radar and target scene, where the movement of a platform upon which the radar's antenna is mounted is calculated utilizing navigation data obtained for the platform. The system and method can generate high-resolution radar images in an almost forward-looking application. This is achieved by introducing an approach compensation (09-17-2009
20090002224SAR ATR tree line extended operating condition - A synthetic aperture radar acquires an image of one or more objects and identifies them as targets. The objects are located in the proximity of clutter within the image such of trees, or a tree line. The radar acquires a SAR image having pixels descriptive of the clutter and the object(s). Regions having object pixels are identified within the synthetic aperture image using an object identification (algorithm), where the object identification (algorithm) utilizes one or more historically known target characteristics and one or more measured characteristic to obtain an output. Boundaries are identified for the one or more objects within the output using an object isolation, such as, for example, a Watershed transform. Clutter pixels are identified external to the one or more objects. The clutter pixels are suppressed from the synthetic aperture image thereby generating a clutter reduced image containing the one or more objects. The objects are compared with known images of a probable target until a match is found, the match representing the target identification.01-01-2009
20100277364TARGET IDENTIFICATION METHOD FOR A SYNTHETIC APERATURE RADAR SYSTEM - In a synthetic aperture radar system (11-04-2010
20110032142SYNTHETIC APERTURE PROCESSING SYSTEM AND SYNTHETC APERTURE PROCESSING METHOD - A synthetic aperture processing system 02-10-2011
20120169532VEHICLE-MOUNTED RADAR DEVICE - Provided is a vehicle-mounted radar device capable of obtaining a high azimuth resolution with a simple configuration.07-05-2012
20120169531WEATHER RADAR BEAM-SHARPENING AND DE-QUANTIZATION - Systems and methods for improving display quality for at range weather data of smaller antenna size radar weather systems. A processor receives a column of quantized reflectivity data associated with an antenna from a radar system. The processor adjusts the column of quantized reflectivity data based on estimated quantized reflectivity data associated with a beam pattern for an antenna that is larger than the antenna associated with the received column of quantized reflectivity data.07-05-2012
20110273326RADAR APPARATUS - A radar apparatus includes: an array antenna having antenna elements having function of a transmission antenna and a reception antenna and receiving an echo signal which is a reflection of a probe signal from a target, the probe signal being radiated from the antenna elements; a converter for converting the echo signal to a baseband signal; a signal synthesizing unit which generates a synthesized baseband signal vector on the basis of aperture synthesis of the baseband signal generated from a combination of the antenna elements giving an equal spatial phase; a correction data acquiring unit which acquires correction data on the basis of coefficients of terms of a synthesized array polynomial; a correction processing unit which corrects the synthesized baseband signal vector on the basis of the correction data; and an estimating unit which performs angle estimation on the basis of the synthesized baseband signal vector.11-10-2011
20120274506PERFORMANCE MODEL FOR SYNTHETIC APERTURE RADAR AUTOMATIC TARGET RECOGNITION AND METHOD THEREOF - A target correlation matrix is generated for multiple two-class combinations of target types each having a target correlation and a synthetic aperture radar observation space. A target probability density of a target radar cross-section signature and a background probability density of a background radar cross-section signature are utilized. The observation space of each of the two-class combinations is partitioned into a target partition and at least one background partition in accordance with the target correlation. A conditional log likelihood is calculated using at least one random number for each of the partitions in accordance with the target probability density and the background probability density, and summed according to the two-class combinations. A maximum log likelihood is calculated from the summed conditional log likelihoods given that one target type of the multiple two-class combinations is assumed to be true. An automatic target recognition performance prediction based on the maximum log likelihood is generated.11-01-2012
20130154876TARGET VELOCITY IDENTIFICATION APPARATUS, TARGET VELOCITY IDENTIFICATION PROGRAM, AND TARGET VELOCITY IDENTIFICATION METHOD - An object of the present invention is to identify the velocity of a target with high precision and with a small amount of computation. A step size determination unit 06-20-2013
20100149023Estimation and Correction of Error in Synthetic Aperture Radar - Methods, systems, and computer-readable media are disclosed for correcting synthetic aperture radar data to correct for gain errors in fast time. According to an embodiment, input data is received from a synthetic radar system representing returned data from an individual pulse. Data entropy optimization is performed to identify a gain correction configured to adjust the input data to minimize image intensity entropy to generate focused output data. The gain correction is applied to the input data to adjust data values in the input data to generate the focused output data.06-17-2010
20090051584Antenna Back-Lobe Rejection - A method of for processing signals in a radar system is shown comprising an antenna system having at least two antenna elements, a beam forming arrangement (ABF_RX, ABF_TX) for selectively steering the directivity of the antenna system in a given selected direction, the directivity of the antenna system having a main lobe in the selected direction and a back lobe (BL) in another direction and of a lower magnitude than the main lobe. By utilizing various scale and subtract processing both noise levels and ghost signals can be considerably reduced. A SAR radar apparatus has moreover been shown.02-26-2009
20130082870SYNTHETIC APERTURE INTEGRATION (SAI) ALGORITHM FOR SAR IMAGING - 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.04-04-2013
20130033394SYNTHETIC APERTURE RADAR CHIP LEVEL CROSS-RANGE STREAK DETECTOR - A method of reducing cross-range streaking in a radar image includes determining a number of on-pixels in each line of at least a portion of the radar image, determining which lines have a determined number of on-pixels that exceeds a threshold number, and removing the on-pixels of lines having the determined number of on-pixels exceeding the threshold number.02-07-2013
20100045512ACTIVE IMAGING USING SATELLITE COMMUNICATION SYSTEM - An active imaging system uses communication satellites to identify the location and physical attributes of a target. A transmitter emits a time-synchronized signal directed to a target. The transmitter radiates L-band RF signals. The transmitter can be positioned on an airborne or ground platform. A constellation of communication satellites receives and time stamps the time-synchronized signal reflected from the target to form an active image of the target. The constellation of communication satellites have multiple roles other than active imaging, such as providing voice and data communications. The time-synchronized signal reflected from the target can be received by multiple satellites within the constellation of communication satellites or by multiple antenna disposed on one satellite within the constellation of communication satellites.02-25-2010
20090303111AUTOFOCUS FOR MINIMUM ENTRY THROUGH MULTI-DIMENSIONAL OPTIMIZATION - A computer implemented method, apparatus, and computer usable program code for focusing an image. In one advantageous embodiment, a method is used to focus an image. Optimization is performed to identify an array of coefficients for a polynomial representing a phase correction in a manner that minimizes an entropy value generated by an entropy calculation for the image. The array of coefficients is applied to the polynomial to obtain a desired phase correction. A phase error in the image is corrected using the desired phase correction to focus the image.12-10-2009
20120218140METHOD AND APPARATUS FOR COMPENSATING FOR A PARAMETER CHANGE IN A SYNTHETIC APERTURE IMAGING SYSTEM - There is described a method for processing data generated by a synthetic aperture imaging system, comprising: receiving raw data representative of electromagnetic signals reflected by a target area to be imaged; receiving a parameter change for the synthetic aperture imaging system; digitally correcting the raw data in accordance with the parameter change, thereby compensating for the parameter change in order to obtain corrected data; and generating an image of the target area using the corrected data.08-30-2012
20090237297Geodesy Via GPS and INSAR Integration - A method for representing surface deformation measurements, including providing InSAR data, wherein the InSAR data is line of sight InSAR data; providing Global Positioning System (GPS) data; filtering the InSAR data; assembling the GPS data over a time span; resolving the GPS data into a line of sight direction; determining a correction; generating a corrected line of sight image; generating a plurality of XY motion maps, wherein generating includes: correlating a plurality of XY motions from a plurality of GPS sites with a gradient of the corrected line of site image; determining a correlation coefficient; and building a plane of XY motion using at least one of the plurality of XY motions; using the correlation coefficient to produce a linear combination of the plurality of XY motion maps; and using the linear combination to convert the InSAR data to vertical motion.09-24-2009
20110012778METHOD AND SYSTEM FOR FORMING VERY LOW NOISE IMAGERY USING PIXEL CLASSIFICATION - A method and system for generating images from projection data comprising inputting from at least one data receiving element first values representing correlated positional and recorded data; each of said first values forming a point in an array of k data points; forming an image by processing the projection data utilizing a pixel characterization imaging subsystem that combines the positional and recorded data to form the SAR imagery utilizing one of a back-projection algorithm or range migration algorithm; integrating positional and recorded data from many aperture positions, comprising: forming the complete aperture A01-20-2011
20110012777Interferometric Synthetic Aperture Radar for Imaging of Buildings - According to one embodiment, a synthetic aperture radar includes multiple antenna elements coupled to an image processing application. The antenna elements have a differing vertical spatial separation relative to one another and are configured to transmit a radio-frequency signal toward a stationary object and receive multiple reflected radio-frequency signals from one or more internal features of the building. The image processing application receives the reflected radio-frequency signals as the antenna elements are moved horizontally with respect to the stationary object. From these reflected radio-frequency signals, the image processing application generates imagery of the stationary object according to phase variations in the plurality of received radio-frequency signals. The imagery depicting vertical characteristics of the one or more internal features of the building.01-20-2011
20120112957MULTIDIRECTIONAL TARGET DETECTING SYSTEM AND METHOD - A method and system for investigating and displaying an image of an area of interest comprising a moving vehicle; at least one processor for producing an image of the area of interest; at least one first transmitter for emitting first signals substantially in a first direction, the at least one first transmitter being operatively associated with the moving vehicle and the processor; at least one first receiver for receiving backscattered signals resulting from the first radar signals, the at least one first receiver being operatively associated with the moving vehicle and the processor; at least one second transmitter operatively for emitting second signals in a direction substantially opposite to the first direction, the at least one second transmitter being operatively associated with the moving vehicle and the processor; at least one second receiver for receiving backscattered signals resulting from the second signals, the at least one second receiver being operatively associated with the moving vehicle and the processor, a GPS subsystem for providing position data relating to the position of the vehicle; the at least one first receiver and the at least one second receiver operating to provide image data to the at least one processor; the at least one processor operating to combine image data from the at least one first receiver and the at least one second receiver with the position data to form a single image; and a display to display the combined image data.05-10-2012
20110090110SYSTEM AND METHOD FOR INSPECTING A WIND TURBINE BLADE - A wind turbine blade inspection system includes a frequency modulated continuous wave radar system configured to be movable with respect to a wind turbine blade while transmitting reference microwave signals and receiving reflected microwave signals and a processor configured for using a synthetic aperture analysis technique to obtain a focused image of at least a region of the wind turbine blade based on the reflected microwave signals.04-21-2011
20110298654SAR RADAR SYSTEM - A method for detecting targets including moving and stationary targets with a radar system equipped with Synthetic Aperture Radar (SAR) onboard a SAR platform including navigation equipment for accurate determination of the position of the SAR platform. The SAR platform is transversing a stationary ground region and targets in the ground region, in which the SAR platform obtains radar data utilizing at least one antenna. A SAR processor records the radar data and the position of the antenna or antennas for each transmitted radar pulse. Radar data within synthetic sub-apertures, are successively merged in N iteration steps into SAR images of increasing resolution of the surveyed region and wherein each iteration step includes forming a new SAR image at a new iteration level by a linear combination of neighboring SAR images in the previous iteration step. A radar system and a SAR processor used for calculating the detection and positioning of targets including moving and stationary targets.12-08-2011
20090289838SYNTHETIC APERTURE RADAR AND METHOD FOR OPERATION OF A SYNTHETIC APERTURE RADAR - The invention relates to a synthetic aperture radar, having a first transmitting and receiving unit for transmission and for reception of a first frequency band, and a second transmitting and receiving unit for transmission and for reception of a second frequency band. According to the invention, the first frequency band and the second frequency band are each provided as a polarized frequency band, and a polarized antenna unit is provided for combination of the first polarized frequency band and of the second polarized frequency band. The synthetic aperture radar according to the invention and the method according to the invention for operation of a synthetic aperture radar have the advantage that they allow better resolution.11-26-2009
20100033367RADAR SYSTEM AND A METHOD RELATING THERETO - A radar system comprising a platform movable along a path in relation to a ground surface portion and carrying a positioning device, a timing device and a radar equipment. It is adapted to implement synthetic aperture radar (SAR) for imaging the ground portion. It includes recording means for collecting radar raw data comprising radar echo amplitudes annotated with distance and the moment of time of collection and being intertwined with platform position measurement data annotated with the respective moment of time of collection thereof.02-11-2010
20080211713METHOD AND DEVICE FOR IMAGING TEST OBJECTS BY MEANS OF ELECTROMAGNETIC WAVES, IN PARTICULAR FOR INSPECTING INDIVIDUALS FOR SUSPICIOUS ITEMS - A method for imaging test objects by means of electromagnetic waves, in particular for the purpose of checking individuals for suspicious articles, in which method the test object is illuminated by electromagnetic waves, the scattered waves are received and evaluated for an imaginal representation of the test object on the basis of the synthetic aperture principle (SAR). A synthetic aperture is produced by the waves output by an antenna being concentrated initially in spatial terms, the point of high concentration being moved on a reflector along a circle.09-04-2008
20110169686TARGET DETECTION IN A SAR-IMAGED SEA AREA - Disclosed herein is a method of detecting a target in a sea area based on a Synthetic Aperture Radar (SAR) image thereof. The Synthetic Aperture Radar (SAR) image is made up of pixels, each having a respective magnitude. The method comprises computing a first reference quantity which characterizes a Poisson distribution assumed for the magnitudes that the pixels in the Synthetic Aperture Radar (SAR) image would have if the sea area were free of targets. The method further comprises selecting pixels in the Synthetic Aperture Radar (SAR) image, computing a real quantity which characterizes a real statistical distribution of the magnitudes of the selected pixels, and detecting a target in the sea area based on the computed first reference and real quantities. The selected pixels are in a one and the same sub-image of the Synthetic Aperture Radar (SAR) image, and detecting comprises detecting a target in a sea subarea of the sea area, the sea subarea being represented by the sub-image.07-14-2011
20090295625Method for Optimizing the Operation of an Active Lateral-View Sensor When the Height Above the Surface to be Detected is Variable - A process for optimizing the operation of an active lateral-view sensor when the height above the surface to be detected is variable, includes the following steps: i) continuously determining the height of the lateral-view sensor above the surface to be detected, and ii) adjusting the scanning beams emitted by the lateral-view sensor for scanning the surface to be detected by roll rotation as a function of the determined height of the lateral-view sensor such that variation of the surface to be detected is reduced during the orbit of the lateral-view sensor.12-03-2009
20090051585Wide area high resolution SAR from a moving and hovering helicopter - A hovering helicopter has a radar transmitter/receiver for transmitting radar pulses for illuminating a target for SAR imaging, and rotor blades for generating lift. Radar reflectors are on the rotor blades. The radar reflectors are oriented to reflect the radar pulses from the transmitter to the target as the rotor blades rotate. The radar pulses reflected by the moving reflector from the transmitter are timed to generate the synthetic aperture image using radar returns from the target. The receiver also receives blade returns directly reflected from the moving reflectors attached to the lift rotor blades. The receiver analyzes the blade returns to extract motion details of the reflectors and uses the motion details for motion compensation of target returns for SAR imaging.02-26-2009
20100103028METHOD OF STRIP-MAP SYNTHETIC APERTURE RADAR AUTO-FOCUS PROCESSING - A strip-map Synthetic Aperture Radar (SAR) auto-focus image generation process is provided. Batches of raw radar return data are processed in order to form batch images which each have a valid region between invalid regions. The process determines an estimate of the first derivative of a phase error at an end of the valid region, determines a time-shift corresponding to that estimate and uses that information in determining a starting point for the next batch of raw radar return data.04-29-2010
20090051586METHOD AND DEVICE FOR HIGH-RESOLUTION IMAGING OF TEST OBJECTS BY ELECTROMAGNETIC WAVES, IN PARTICULAR FOR MONITORING PEOPLE FOR SUSPICIOUS ITEMS - In order to image test objects by electromagnetic waves, in particular millimetric waves, a test object is illuminated with the electromagnetic waves, the scattered waves are received, and are evaluated for a representation of the test object in the form of an image based on the principle of “synthetic aperture radar” (SAR). In order to allow as large an area as possible to be imaged with high resolution in a short time, the phase centres of the transmitting and receiving antennas are, according to the invention, moved on a circular path parallel to the respective digital focus planes of the imaging system, and are at the same time shifted linearly in a further direction parallel to the respective focus plane. The method can be used for monitoring people for suspicious objects, for example for monitoring airline passengers at an airport.02-26-2009
20110006944COMPUTATIONALLY EFFICENT RADAR PROCESSING METHOD AND SYTEM FOR SAR AND GMTI ON A SLOW MOVING PLATFORM - A method and system for processing radar data obtained from a platform which is subjected to non-uniform movement, the distance the platform travels during the formation of an image comprising an aperture; the system comprising software programming for performing a subroutine for building up an average pulse representing a single point on the aperture; the subroutine comprising the steps of inputting radar data from a radar antenna; passing the radar signal through low noise amplifier to reduce impact of electronic noise from the radar system; down converting the signal with a mixer to obtain a lower frequency; filtering out harmonics from the higher frequency range; sampling the radar data using an analog to digital converter at least at Nyquist down range frequency; based upon the IF of the radar; determining a scene center (center of SAR imagery) for the purpose of motion compensation; performing a two stage averaging scheme of the received signals with a variable window function; determining a window function based upon the velocity and acceleration of the platform and scene center; the window function comprising a first stage window; coherently averaging N pulses together to create an average pulse; performing an inverse Fourier transform; compensating to the scene center by multiplying by a complex exponential based upon both the GPS and inertial navigational system; summing the average pulses using low pass filter; the software programming operating to repeat the step of building up an average pulse a first predetermined number of times for a time period that is less than the Nyquist sample time interval; the software programming operating to repeat the step of building an average pulse for a predetermined number of times to generate a second predetermined number of average pulses; the software programming operating to perform a two dimensional inverse Fourier transform to obtain SAR image; outputting the SAR image on a display screen; and a display for displaying the outputted SAR image.01-13-2011
20090102704SYNTHETIC APERTURE RADAR, COMPACT POLARIMETRIC SAR PROCESSING METHOD AND PROGRAM - To provide a synthetic aperture radar for achieving a compact polarimetric SAR easily by using a general-purpose phased array antenna for vertical and horizontal polarizations. An antenna section is a phased array antenna for vertical and horizontal polarizations capable of switching to the vertical or horizontal polarizations in transmission at every transmission/reception module, and receiving two of the horizontal and vertical polarizations simultaneously. The control system divides electrically the phased array antenna in the elevation direction in transmission to set one of them for horizontal polarization transmission and the other for vertical polarization transmission, and sets the antenna for dual polarization simultaneous reception to receive the horizontal and vertical polarizations. The SAR processor takes complex data of horizontal and vertical polarization receiving data as a target vector, and obtains a calculation result corresponding to a covariance matrix of a target vector in full polarimetry so as to perform polarimetric SAR processing.04-23-2009
20120105275DETECTION SYSTEM AND METHOD USING GRADIENT MAGNITUDE SECOND MOMENT SPATIAL VARIANCE DETECTION - A detection system includes a detection processor configured to receive a frame of image data, that includes a range/Doppler matrix, perform a rate-of-change of variance calculation with respect to at least one pixel in the frame of image data, and compare the calculated rate-of-change of variance with a predetermined threshold to provide output data. The range/Doppler matrix may include N down-range samples and M cross-range samples. The detection processor may calculate a rate-of-change of variance over an N×M window within the range/Doppler matrix.05-03-2012
20120105274RADAR SYSTEM AND METHOD FOR A SYNTHETIC APERTURE RADAR - A radar system for a synthetic aperture radar including an arrangement of at least one transmitter, two receivers, two antennas and signal processing means located on a platform. The platform is arranged to move over ground and arranged to transmit a known signal shape and receive signals reflected from the ground. The received signals are used to produce a synthetic aperture radar image of the ground. The synthetic aperture radar image includes a number of resolution cells. The radar system is further arranged to operate in a frequency band with a center frequency and with a wide bandwidth of at least one octave. A first antenna and a second antenna have a length of less than half the wavelength of the center frequency. The radar system is further arranged for: a radar system transfer function to be flat over the frequency band and one-sided beam forming with wideband antenna gain. Also a corresponding method.05-03-2012
20090273509MICROWAVE IMAGING SYSTEM AND METHOD - A system and method for using microwaves for forming a three-dimensional image of a target are disclosed. One or more RF waveforms are emitted toward the target on a plurality of frequencies from an array of antennas positioned around the target. Each antenna in the array of antennas is selectively controlled to receive multi-frequency RF energy from one or more emitted RF waveforms that is scattered by the target. The multi-frequency RF energy is coherently digitized as reflection data. The reflection data is then processed to form a three-dimensional image of an area in proximity of the platform and including the target.11-05-2009
20090079621HIGH-RESOLUTION SYNTHETIC APERTURE RADAR DEVICE AND ANTENNA FOR ONE SUCH RADAR - The invention relates to a high-resolution synthetic aperture radar device (03-26-2009
20100225531System, Method, and Apparatus for Remote Measurement of Terrestrial Biomass - A system, method, and/or apparatus for remote measurement of terrestrial biomass contained in vegetative elements, such as large tree boles or trunks present in an area of interest, are provided. The method includes providing an airborne VHF radar system in combination with a LiDAR system, overflying the area of interest while directing energy toward the area of interest, using the VHF radar system to collect backscatter data from the trees as a function of incidence angle and frequency, and determining a magnitude of the biomass from the backscatter data and data from the laser radar system for each radar resolution cell. A biomass map is generated showing the magnitude of the biomass of the vegetative elements as a function of location on the map by using each resolution cell as a unique location thereon. In certain preferred embodiments, a single frequency is used with a linear array antenna.09-09-2010
20090289837Map Information Update Support Device, Map Information Update Support Method and Computer Readable Recording Medium - A map information update support device includes a communication interface unit that acquires plural items of radar image data of the same observation area acquired at different times, respectively, a registration processing unit that registrates the plural items of radar image data with respect to one another, a characteristic value calculation unit that calculates a characteristic value representing a state of a surface of the earth in the observation area using the items of radar image data after the registration process, a feature changed area extraction unit that extracts a feature changed area based on the characteristic value, a road change candidate area extraction unit that synthesizes the feature changed area with map information of the observation area and extracts a road change candidate area that is a candidate of a road changed portion, and an output unit that outputs the map information synthesized with the road change candidate area.11-26-2009
20110018756Synthesized Aperture Three-Dimensional Radar Imaging - A synthesized aperture radar imaging system is disclosed. The system includes an antenna reflector and a radar signal transceiver configured to generate a plurality of radar transmission signals and to receive a respective plurality of reflected radar signals. The system also includes a wave reflection device configured to sequentially reflect each of the plurality of radar transmission signals onto separate respective spot-portions of the antenna reflector. The plurality of radar transmission signals can be transmitted from the antenna reflector to a target and reflected from the target as the respective plurality of reflected radar signals. The system further includes a synthesized aperture radar controller configured to integrate the plurality of reflected radar signals and to generate a high-resolution, three-dimensional image of the target from the integrated plurality of reflected radar signals.01-27-2011
20110043402TERRESTRIAL OBJECT INFORMATION JUDGING IMAGE PRODUCING METHOD AND PROGRAM - In the case where radar image data obtained from a radar device equipped in a flying body and optical image data of a district taken by the radar device are synthesized to produce a terrestrial object information judging image, the radar image data are approximated to a black and white panchromatic image character. The radar image data approximated to the black and white panchromatic character and the optical image data are aligned in position and then synthesized. As a suitable embodiment, in an approximation processing of the radar image data to the black and white panchromatic image character, histogram conversion processing is carried out in accordance with a histogram characteristic of the radar image data.02-24-2011
20100295725METHOD AND DEVICE FOR SYNTHETIC IMAGING - A method of synthetic imaging comprising the steps of: emitting a first electromagnetic signal having a first frequency from a first radiation source, emitting at least one second electromagnetic signal having a second frequency from a second radiation source, wherein the first and second frequencies are different from each other, substantially simultaneously receiving the first signal and the second signal with a first receiver, substantially simultaneously receiving the first signal and the second signal with at least one second receiver, arranging an object on the path of at least one electromagnetic signal between the radiation sources and the receivers, wherein the signals are reflected by the object before they meet the receivers, and computing an image of the object from the signals received by the receivers and a device for practicing the method.11-25-2010
20110254728THREE QUARTER SPATIALLY VARIANT APODIZATION - A new spatially variant apodization (SVA) algorithm that uses a 3/4 filled aperture prior to two dimensional discrete Fourier transform (2-D DFT) to form the image. The algorithm can be used, for example, to improve contrast and resolution on synthetic aperture radar (SAR) imagery, with a lower degree of oversampling (and thus, fewer pixels) than other algorithms require. This can translate into more efficient use of radar displays and processor memory. Additional efficiencies of memory and computing power may be realized when Automatic Target Recognition (ATR) algorithms operate on this imagery. Embodiments of this invention use convolution kernels at two different spacings, which are better tuned to the local phase relationships of mainlobe and sidelobes with a 3/4 filled aperture. As such, these embodiments suppress sidelobes without sacrificing resolution, at an aperture-filling ratio of 3/4, rather than 1/2, as is usually used.10-20-2011
20100321234COMPUTATIONALLY EFFICENT RADAR PROCESSING METHOD AND SYTEM FOR SAR AND GMTI ON A SLOW MOVING PLATFORM - A method and system for processing radar data obtained from a platform which is subjected to non-uniform movement, the distance the platform travels during the formation of an image comprising an aperture; the system comprising software programming for performing a subroutine for building up an average pulse representing a single point on the aperture; the subroutine comprising the steps of inputting radar data from a radar antenna; passing the radar signal through low noise amplifier to reduce impact of electronic noise from the radar system; down converting the signal with a mixer to obtain a lower frequency; filtering out harmonics from the higher frequency range; sampling the radar data using an analog to digital converter at least at Nyquist down range frequency; based upon the IF of the radar; determining a scene center (center of SAR imagery) for the purpose of motion compensation; performing a two stage averaging scheme of the received signals with a variable window function; determining a window function based upon the velocity and acceleration of the platform and scene center; the window function comprising a first stage window; coherently averaging N pulses together to create an average pulse; performing an inverse Fourier transform; compensating to the scene center by multiplying by a complex exponential based upon both the GPS and inertial navigational system; summing the average pulses using low pass filter; the software programming operating to repeat the step of building up an average pulse a first predetermined number of times for a time period that is less than the Nyquist sample time interval; the software programming operating to repeat the step of building an average pulse for a predetermined number of times to generate a second predetermined number of average pulses; the software programming operating to perform a two dimensional inverse Fourier transform to obtain SAR image; outputting the SAR image on a display screen; and a display for displaying the outputted SAR image.12-23-2010
20110043403MILLIMETER WAVE CAMERA WITH IMPROVED RESOLUTION THROUGH THE USE OF THE SAR PRINCIPLE IN COMBINATION WITH A FOCUSING OPTIC - The present invention concerns an apparatus for and a method of imaging an object by means of electromagnetic very high frequency radiation. The state of the art discloses systems for and methods of imaging with a synthetic aperture, which distinguish the signals emitted by individual transmitting antennas from each other after reflection thereof by an object upon reception on a plurality of receivers. In that respect systems are known which for that purpose use a row-like arrangement of transmitters and receivers, wherein an object is rotated on a motor-driven platform in front of the transmitter or receiver row. In comparison the object of the present invention is to provide an apparatus for and a method of imaging an object, which make it possible to achieve as high a resolution as possible with as low a number of transmitters and receivers as possible. To attain that object in accordance with the invention there is proposed an apparatus for imaging an object by means of electromagnetic very high frequency radiation comprising at least two receivers for the very high frequency radiation, wherein the receivers are arranged in a row configuration, a control operating the receivers in such a way that they produce a synthetic aperture image in a direction parallel to the row and an imaging optical means which is so adapted that it causes optical imaging only in planes substantially perpendicular to the row.02-24-2011
20100283667Radar imaging system and method using second moment spatial variance - A detection system and method. The inventive system includes an arrangement for receiving a frame of image data; an arrangement for performing a variance calculation with respect to at least one pixel in the frame of image data; and an arrangement for comparing the calculated variance with a predetermined threshold to provide output data. In the illustrative embodiment, the frame of image data includes a range/Doppler matrix of N down range samples and M cross range samples. In this embodiment, the arrangement for performing a variance calculation includes an arrangement for calculating a variance over an N×M window within the range/Doppler matrix. The arrangement for performing a variance calculation includes an arrangement for identifying a change in a standard deviation of a small, localized sampling of cells. In accordance with the invention, the arrangement for performing a variance calculation outputs a variance pixel map.11-11-2010
20100259442FAST IMPLEMENTATION OF A MAXIMUM LIKELIHOOD ALGORITHM FOR THE ESTIMATION OF TARGET MOTION PARAMETERS - A system and method for implementing a maximum likelihood estimator for making a joint estimation of range, range rate, and acceleration of a target utilizing a pulse doppler radar. The MLE of target motion parameters are determined by keystone processing a baseband signal, and generating a first estimate of the motion parameters based on the processed signal. The first estimate is utilized to set up sampling intervals for the performance of a coarse search. Then a fine search is performed using Newton's method to determine the MLE.10-14-2010
20090167595SYSTEM AND METHOD FOR 3D RADAR IMAGE RENDERING - A 3D rendered image of a radar-scanned terrain surface is provided from a radar return signal from the surface, wherein the return signal includes data indicative of azimuth, elevation, and range of a radar-illuminated area of the surface. The data are processed for transformation into X, Y, and Z coordinates. The X and Y coordinates corresponding to each illuminated area are triangulated so as to create a mesh of triangles representing the terrain surface, each of the triangles in the mesh being defined by a vertex triplet. 3D imaging information (grey scale shading and/or coloring information) is added to each triangle in the mesh, based on the amplitude of the radar return signal from the coordinates represented by each vertex in the triplet and the value of the Z coordinate at each vertex, so as to form the 3D rendered image.07-02-2009
20090167596METHOD OF PROCESSING A RADAR IMAGE - Embodiments of the invention process a radar image arising from a radar antenna, by reading the reflectivity information associated with each pixel forming the radar image, processing the reflectivity information, pixel by pixel, with the aid of a first procedure. The method further includes a second processing of the radar image using a second procedure that includes extracting objects from the radar image, then calculating the extent and the position of each object, with the aid of an angular aperture between two signals. For each part of the radar image processed by the first procedure, corresponding to an extracted object, pixel within the result of the first procedure are replaced by corresponding pixels of the radar image processed by the second procedure, if the reflectivity value associated with the second pixel is greater than the reflectivity value of the first pixel, the parts of the radar image corresponding to zones situated at a distance greater than a given threshold from the radar antenna.07-02-2009
20120013501PROCESS FOR IDENTIFYING STATISTICALLY HOMOGENEOUS PIXELS IN SAR IMAGES ACQUIRED ON THE SAME AREA - A process is disclosed for identifying statistically homogeneous pixels in images acquired on the same area by means of a synthetic aperture radar (SAR sensor) comprising the following steps: (a) acquiring a plurality of N radar images (A01-19-2012
20120206292Synthetic Aperture Radar Image Formation System and Method - A saturated input signal acquired by a synthetic aperture radar (SAR) system is processed by estimating a reconstruction that generated the input signal, reproducing an input signal from an estimated reconstruction to generate a reproduced signal, comparing the reproduced signal with the input signal; adjusting an estimated reconstruction based on the comparison; and iterating from the reproducing step until a termination condition is reached.08-16-2012
20130009806SIGNAL PROCESSING METHODS AND APPARATUS - A signal processor performs a signal transform of a signal, and comprises a signal demodulator for demodulating said signal by a first chirp signal having a first chirp rate to obtain a reduced bandwidth chirped signal, a filter for filtering the reduced bandwidth chirped signal and delaying the reduced bandwidth chirped signal by an interval proportional to a reciprocal of said first chirp rate, a signal modulator for modulating said filtered signal by a second chirp signal having a second chirp rate to obtain an increased bandwidth chirped signal and to provide a time domain output spectrum of said signal, and wherein each of said first chirp signal and said second chirp signal is a complex signal representing a linear frequency modulated chirp.01-10-2013
20110175770High Resolution SAR Imaging Using Non-Uniform Pulse Timing - A synthetic aperture radar (SAR) system includes a non-uniform pulse generator, and an echo receiver. A SAR image is reconstructed from samples of received echoes, wherein transmitted pulses and reflected echoes overlap in time.07-21-2011
20120133550Method for Determining the Geographic Coordinates of Pixels in SAR Images - A method for effecting the airborne determination of geographic coordinates of corresponding pixels from digital synthetic aperture radar images, where the SAR images are available in the form of slant range images and the recording position of the respective SAR image is known. The coordinates of the corresponding pixels in the SAR images and the corresponding range gates are used in each case to determine the distance between a corresponding resolution cell on the ground and the respective recording position of the respective SAR image. The determined distances and associated recording positions of the SAR images are used to determine the geographic coordinates of the corresponding pixels in the SAR images by employing a WGS84 ellipsoid.05-31-2012
20100007549SYSTEM AND METHOD FOR BISTATIC CHANGE DETECTION FOR PERIMETER MONITORING - A method for monitoring an area that involves transmitting a first electromagnetic wave signal from a mobile platform moving over a ground surface, toward the ground surface. A receiver is used that is located remote from the mobile platform to receive the first electromagnetic wave signal after the signal is reflected from the ground surface. The first electromagnetic wave signal is processed to form a first synthetic aperture radar (SAR) image. Subsequently the receiver is used to receive a second electromagnetic wave signal transmitted from the mobile platform at a time subsequent to transmission of the first electromagnetic wave signal. The second electromagnetic wave signal is then processed to obtain a second SAR image. The first and second SAR images are then coherently analyzed to determine areas of non-correlation between the images.01-14-2010
20100283668Radar imaging system and method using gradient magnitude second moment spatial variance detection - A detection system and method. The inventive system includes an arrangement for receiving a frame of image data; an arrangement for performing a rate of change of variance calculation with respect to at least one pixel in said frame of image data; and an arrangement for comparing said calculated rate of change of variance with a predetermined threshold to provide output data. In the illustrative embodiment, the frame of image data includes a range/Doppler matrix of N down range samples and M cross range samples. In this embodiment, the arrangement for performing a rate of change of variance calculation includes an arrangement for calculating a rate of change of variance over an N×M window within the range/Doppler matrix. The arrangement for performing a rate of change of variance calculation includes an arrangement for identifying a change in a standard deviation of a small, localized sampling of cells. In accordance with the invention, the arrangement for performing a rate of change of variance calculation outputs a rate of change of variance pixel map.11-11-2010
20090303110CELESTIAL BODY MAPPING SYSTEMS AND METHODS - Systems and methods for mapping a surface of a celestial body containing objects and terrain are provided. One system includes a Synthetic Aperture RADAR (SAR) module configured to capture a high-resolution image of the terrain of at least a portion of the surface and a map module configured to store map data representing the portion of the surface. The system also includes a fusion module configured to combine the high-resolution image and the map data to generate a high-resolution map of the portion of the surface. A method includes orbiting the celestial body, capturing, via the SAR module, a high-resolution image during each orbit, and fusing the captured high-resolution image with a low-resolution map of the surface to generate a high-resolution map of the surface. A computer-readable medium for storing instructions that cause a processor to perform the above method is also provided.12-10-2009
20090021423METHOD AND APPARATUS FOR THREE DIMENSIONAL TOMOGRAPHIC IMAGE RECONSTRUCTION OF OBJECTS - In accordance with an embodiment, a system includes a plurality of vehicles and a central node. The plurality of vehicles each have radar systems used to collect radar data about the target object. Each in the plurality of vehicles moves in a path to collect a portion of the radar data using a sampling map to coordinate collection of the radar data by the plurality of vehicles and communicates with every other vehicle to identify uncollected portions of the radar data. The central node is in communication with the plurality of vehicles, wherein the central node receives the radar data from the plurality of vehicles and creates a three dimensional image from the radar data received from the plurality of vehicles using a tomographic reconstruction process.01-22-2009
20100321235Imaging Method Utilizing a Synthetic Aperture, Method for Determining a Relative Velocity Between a Wave-Based Sensor and an Object, or Apparatus for Carrying Out the Methods - An imaging method is provided for imaging or locating an object with a wave-based sensor. A wave field emanates from the object as an object signal, with this object signal emanating from a sensor is received at a sensor position, and wherein the sensor(s) and the object assume a number of spatial positions with respect to each other and form a synthetic aperture, and an echo signal is sensed at each of these sensor positions, a number of function values is extracted from the echo signals, which are allocated to a space coordinate of the object, and a signal with a residual phase characteristic is formed from the function values. Based on a residual phase characteristic that is due to a deviation of real sensor positions from assumed or measured sensor positions, an image point, the object position or the relative movement of the object is determined.12-23-2010
20090309786Synthetic aperture radar system - An imaging system for generating a three dimensional image of tissue of a patient is provided. The imaging system comprises of a transmitter, receiver, antenna system and a display element to form a synthetic aperture radar system that displays a three dimensional view of the tissue. The SAR system has been configured to operate in the near field as opposed to current equipment which can only perform satisfactorily in the far field. A calibration technique has been utilized that allows the system to perform as well as other systems that operate using far field techniques but allows for a much simpler, cost effective system.12-17-2009
20100231441Vehicular Surveillance System Using a Synthetic Aperture Radar - According to one embodiment, a system for gathering intelligence, surveillance, and reconnaissance information comprises a synthetic aperture radar that is housed within an enclosure coupled to a land vehicle. The synthetic aperture radar includes an antenna array that transmits and receives electro-magnetic radiation for generating images of objects around the land vehicle while the land vehicle is in motion.09-16-2010
20120274505AUTOMATED REGISTRATION OF SYNTHETIC APERTURE RADAR IMAGERY WITH HIGH RESOLUTION DIGITAL ELEVATION MODELS - A method, a radar image registration manager, and a set of instructions are disclosed. A primary sensor interface 11-01-2012
20130099960ICE DATA COLLECTION, PROCESSING AND VISUALIZATION SYSTEM - Autonomous Underwater Vehicles (AUV) collect and transmit information about ice floe thickness; this is combined with SYNTHETIC APERTURE RADAR images from satellites to identify and track dangerously thick regions of ice. The overlayed data is presented graphically to allow tracking of the thick ice regions over time. This information is used to alert drilling platforms in icy ocean conditions of pending ice floe dangers.04-25-2013
20100045513STABILITY MONITORING USING SYNTHETIC APERTURE RADAR - A stability monitoring system is described that provides an accurate, automated, and remote way of monitoring small movements over a large surface area without the need to pre-place reflective targets using a mobile SAR. The stability monitoring system allows the rapid, automated identification and measurement of small surface movements over a wide field of view from a safe standoff distance without the need for personnel working in hazardous zones. Using this data, authorities can more accurately identify hazard areas and efficiently allocate mitigation resources.02-25-2010
20090091492Detection and mitigation radio frequency memory (DRFM)-based interference in synthetic aperture radar (SAR) images - Methods and systems for detecting and mitigating DRFM-based interference in SAR images are provided. Embodiments include methods and systems for detecting and removing DRFM-based interference from SAR images by exploiting multi-channel SAR data. Embodiments provide an Electronic Counter Counter Measure (ECCM) technique that is effective against, among others, SAR DRFM-based repeater jamming, false target images, noise jamming, and vector multiplier jamming for false scene generation. When used, embodiments of the present invention reduce jammer effectiveness to a small range strip (a strip parallel to the range dimension) in the direction of the jammer. In addition, jammer mitigation is performed without losing SAR image data at the affected SAR pixels. Furthermore, embodiments of are compatible with time variable ECCM techniques, including orthogonal waveforms or pulse jitter techniques, for example.04-09-2009
20110298655Synthetic-aperture radar system and operating method for monitoring ground and structure displacements suitable for emergency conditions - A synthetic-aperture radar system, and related operating method, for the monitoring of ground and structure movements, particularly suitable for emergency conditions, characterized by a ground based platform with polarimetric capabilities, that able to quickly acquire, embeddedly process and post-process data by a novel data acquisition “On the Fly” mode of operation, reducing by at least an order of magnitude the data acquisition time. The inventive system characteristics allows to achieve on-field measurement results on three-dimensional maps georeferenced to absolute coordinate systems (WGS84, Gauss-Boaga, and so on). The operating method includes the step of installing the system, the acquiring of the first measurements, the quick data processing and post-processing to provide sub-millimetric precision georeferenced bi-dimensional and three-dimensional displacement maps for the objects belonging to the monitored scenario, with an improved performance and in a measurement time compatible to that required in an emergency condition, with an higher degree of integration with other sensors and autonomously and embeddendly.12-08-2011
20110163911Identification and Analysis of Persistent Scatterers In Series of SAR Images - Disclosed herein is a method for identifying persistent scatterers in digital “Synthetic Aperture Radar” images of an area of Earth's surface each taken at a respective time. The method involves processing the digital Synthetic Aperture Radar images to produce digital generalized differential interferograms. The method further involves analyzing properties of pairs of pixels in the digital generalized differential interferograms to identify individual pixels imaging persistent scatterers.07-07-2011
20120127028METHOD FOR GEO-REFERENCING OF OPTICAL REMOTE SENSING IMAGES - In the method for geo-referencing of optical remote sensing images of an area of the earth's surface, the geo-referencing is corrected based on an SAR image which is geo-referenced.05-24-2012
20120188119Identification and Analysis of Persistent Scatterers In Series of SAR Images - Disclosed herein is a method for identifying persistent scatterers in digital “Synthetic Aperture Radar” images of an area of Earth's surface each taken at a respective time. The method involves processing the digital Synthetic Aperture Radar images to produce digital generalized differential interferograms. The method further involves analyzing properties of pairs of pixels in the digital generalized differential interferograms to identify individual pixels imaging persistent scatterers.07-26-2012
20120229331SYNTHETIC APERTURE IMAGING INTERFEROMETER - There is described a method for generating a synthetic aperture image of a target area, comprising: receiving, from a synthetic aperture imaging system, first raw data representative of electromagnetic signals reflected by the target area and detected by the synthetic aperture imaging system according to a first angle of view; digitally combining the first raw data with second raw data, thereby obtaining combined data, the second raw data being representative of the electromagnetic signals reflected by the target area and detected by the synthetic aperture imaging system according to a second angle of view different from the first angle of view; and generating an interference pattern of the target data using the combined data.09-13-2012
20120319892Acquisition of SAR images for computing a height or a digital elevation model by interferometric processing - The present invention relates to a method for acquiring SAR images for interferometric processing. The method comprises acquiring, by one or more airborne SAR sensors, SAR images of one and the same area with an acquisition geometry such that to enable interferometric processing of said SAR images. The method is characterized by an acquisition geometry in which each SAR image of the area is acquired in a respective direction of acquisition that defines a respective squint angle with respect to the direction of flight, and in which the squint angles are such that to determine a mean squint angle different from zero.12-20-2012
20120319893DAMAGE PROXY MAP FROM INTERFEROMETRIC SYNTHETIC APERTURE RADAR COHERENCE - A method, apparatus, and article of manufacture provide the ability to generate a damage proxy map. A master coherence map and a slave coherence map, for an area prior and subsequent to (including) a damage event are obtained. The slave coherence map is registered to the master coherence map. Pixel values of the slave coherence map are modified using histogram matching to provide a first histogram of the master coherence map that exactly matches a second histogram of the slave coherence map. A coherence difference between the slave coherence map and the master coherence map is computed to produce a damage proxy map. The damage proxy map is displayed with the coherence difference displayed in a visually distinguishable manner.12-20-2012
20120019410PROCESS FOR FILTERING INTERFEROGRAMS OBTAINED FROM SAR IMAGES ACQUIRED ON THE SAME AREA - A process for filtering interferograms obtained from SAR images, acquired on the same area by synthetic aperture radars, comprising the following steps: a) acquiring a series of N radar images (Al . . . AN) by means of a SAR sensor on a same area with acquisition geometries such as to allow re-sampling of the data on a common grid; b) after re-sampling on a common grid, selecting a pixel from the common grid; c) calculating the coherence matrix of the selected pixel, that is estimating the complex coherence values for each possible pair of available images; d) maximizing, with respect of the source vector θ, here an unknown element, the functional: (formula) being R the operator which extracts the real part of a complex number, γ01-26-2012
20100164785SYNTHETIC APERTURE RADAR PROCESS - A continually adapted pulse-to-pulse shift, performed in the azimuth direction, of the phase center which is electrically active on the side of the transmitting antenna (Tx; Tx07-01-2010
20100039313Synthetic Aperture Radar (SAR) Imaging System - One embodiment of the invention includes a synthetic aperture radar (SAR) system. The system comprises a radar transmitter configured to transmit a combined signal, the combined signal comprising a first signal that is a modulated SAR radar signal and a second signal that is a modulated signal. The system also comprises at least one radar receiver configured to receive a reflected combined signal that comprises a reflected first signal and a reflected second signal, and to demodulate the reflected first and second signals. The reflected first and second signals can correspond to the first and second signals having been reflected from a target. The system further comprises a radar image processor configured to generate a radar image of the target based on signal parameters associated with the reflected first signal and based on information comprised within the reflected second signal.02-18-2010
20100019957TIME-COMPRESSED CLUTTER COVARIANCE SIGNAL PROCESSOR - The time compression processor coding methodology gives rise to an exceedingly fast clutter covariance processor compressor (CCPC). The CCPC includes a look up memory containing a very small number of predicted clutter covariances (PCCs) that are suitably designed off-line (e.g., in advance) using a discrete number of clutter to noise ratios (CNRs) and shifted antenna patterns (SAPs), where the SAPs are mathematical computational artifices not physically implemented. The on-line selection of the best PCC is achieved by investigating for each case, e.g., each range bin, the actual CNR, as well as the clutter cell centroid (CCC), which conveys information about the best SAP to select. The advanced CCPC is a ‘lossy’ processor coder that inherently arises from a novel practical and theoretical foundation for signal processing, namely, processor coding, that is the time compression signal processing dual of space compression source coding.01-28-2010
20100066598NON-STATISTICAL METHOD FOR COMPRESSING AND DECOMPRESSING COMPLEX SAR DATA - Provided is a non-statistical method for compressing and decompressing complex SAR data derived from reflected energy. The method includes selecting a first FFT to provide a target ratio of pixel spacing to resolution. A second FFT is then selected which is smaller than the first FFT. The data is zero-padded to fill the second FFT and transformed to provide at least one transfer frequency. This transfer frequency is then transferred to the at least one remote site. At the remote site the second FFT is inverted to restore the data from the received transfer frequency. The restored data is then zero-padded again to fill the first FFT. The first FFT is then used to transform the zero-padded restored data to provide a data set of points with the target ratio of pixel spacing to resolution.03-18-2010
20120105276SYNTHETIC APERTURE RADAR (SAR) IMAGING SYSTEM - One embodiment of the invention includes a synthetic aperture radar (SAR) system including a receiver configured to receive a plurality of reflected radar pulses corresponding to a plurality of radar transmission pulses having been reflected from a target region. A processing controller divides the target region into a plurality of tiles at a highest data layer and each of the plurality of tiles into a plurality of sub-tiles corresponding to one of a plurality of data layers and iteratively processes a portion of pulse data corresponding to a given tile associated with a higher data layer to generate pulse data corresponding to a given sub-tile in a lower data layer. An image processor is configured to generate a radar image of the target region based on the pulse data corresponding to each of the plurality of sub-tiles associated with a lowest data layer of the plurality of data layers.05-03-2012
20100214160SYNTHETIC APERTURE RADAR SYSTEM AND METHODS - A compact synthetic aperture radar system and associated methods are disclosed.08-26-2010
20110285580Method for constructing focused radar images - A method for constructing focused radar images includes chopping the radar illumination period into p sub-periods, two successive sub-periods overlapping temporally; choosing n successive sub-periods from among the p sub-periods, and for each of the n chosen sub-periods, performing radar acquisitions to generate an image IM_011-24-2011
20110285581Surveillance System Comprising a Radar Antenna Mounted on a Blade of a Windmill - A surveillance system for detecting targets comprises a radar antenna mounted on a blade of a windmill.11-24-2011
20110163912SYSTEM AND METHOD FOR ITERATIVE FOURIER SIDE LOBE REDUCTION - A method and system for generating images from projection data comprising: at least one processor for processing input data, the input data comprising positional data and image data, the image data comprising frequency data for a pre-determined number k frequencies the at least one processor operating to: a) set the frequency data to zero for a predetermined percentage of the k frequencies to form modified frequency data; b) form a preliminary image comprising an array of retained pixel values based upon first positional data and the modified frequency data; c) set the frequency data to zero for a predetermined percentage of the k frequencies to form modified frequency data; d) form a modified image comprising an array of pixels based upon the positional data and the modified frequency data; e) compare the retained array of pixel values to the pixel values of the modified image formed at step (d); f) retain the minimum pixel value at each pixel location to form an image comprising minimum pixel values; g) repeat steps (c) through (f) for L iterations each time retaining an array of pixel values; h) output the image of retained pixel values.07-07-2011
20100052977Inverse Synthetic Aperture Radar Image Processing - According to one embodiment, inverse synthetic aperture radar (ISAR) image processing includes receiving an ISAR image from an inverse synthetic aperture radar. A standard deviation profile is generated from the ISAR image, where the standard deviation profile represents a standard deviation of the ISAR image. The standard deviation profile is normalized to form a normalized standard deviation profile. A mean value profile is generated from the ISAR image, where the mean value profile represents a mean value deviation of the ISAR image. The mean value profile is normalized to form a normalized mean value profile. The normalized standard deviation profile and the normalized mean value profile are combined to form a sum normalized range profile. The sum normalized range profile may be processed to classify a target in the ISAR image.03-04-2010
20100090887MULTI-PIXEL HIGH-RESOLUTION THREE-DIMENSIONAL IMAGING RADAR - 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.04-15-2010
20110169687SYSTEM AND METHOD FOR DETECTING DAMAGE, DEFECT, AND REINFORCEMENT IN FIBER REINFORCED POLYMER BONDED CONCRETE SYSTEMS USING FAR-FIELD RADAR - A non-contact, far-field radar nondestructive testing (NDT) method is disclosed that is capable of detecting at least one of defects, damages, and reinforcement conditions in near-surface region of multi-layer systems using monostatic inverse synthetic aperture radar (ISAR) measurements and applicable to various types of structural elements. The method includes the steps of conducting far-field monostatic ISAR measurements, executing an imaging algorithm, and executing a progressive image focusing algorithm.07-14-2011
20100001901Apparatus and Method for Compressive Sensing Radar Imaging - Method and apparatus for developing radar scene and target profiles based on Compressive Sensing concept. An outgoing radar waveform is transmitted in the direction of a radar target and the radar reflectivity profile is recovered from the received radar wave sequence using a compressible or sparse representation of the radar reflectivity profile in combination with knowledge of the outgoing wave form. In an exemplary embodiment the outgoing waveform is a pseudo noise sequence or a linear FM waveform.01-07-2010
20090102705Spectrometric synthetic aperture radar - This invention relates to improved ultra-wideband synthetic aperture radar and inverse synthetic aperture radar, capable of simultaneously and independently imaging a plurality of spectral and polarimetric channels covering multiple radio frequency octaves. Advances in technologies relating to signal processing, graphical user interfaces, color representations of multi-spectral radar images, low aerodynamic drag polarimetric SAR antenna systems, and synthetic aperture radar aircraft platforms are some of the advancements disclosed herein.04-23-2009
20100141508METHOD AND SYSTEM FOR FORMING AN IMAGE WITH ENHANCED CONTRAST AND/OR REDUCED NOISE - A method and system for generating images from projection data; a preferred embodiment comprising inputting projection data from at least one receiving element; generating a first aperture or array of data points containing positional and signal data; arbitrarily and/or randomly removing data points from the first array to form a series of subarrays comprising different sets of data points; generating preliminary images from the subarrays; comparing the corresponding image pixels from two preliminary images to determine for each pixel location the lesser or equal pixel values; forming a merged image from the lesser or equal pixel values; and repeating the comparison of corresponding image pixels of another preliminary image to the merged image to determine the lesser or equal pixel values until a merged image of the desired quality is obtained. A preferred embodiment of the system may comprise at least one processor, comparator and/or image generator.06-10-2010
20110267223System and Method for Resolving Ambiguity in Radar, Lidar, and Acoustic Systems - Range and Doppler ambiguities are common in radar, lidar, and acoustic systems. Resolving these ambiguities is important to achieve desirable geolocation and image quality performance in these systems. A new method is described to iteratively resolve the ambiguities. For Doppler ambiguity applications, a first PRF value and an initial Doppler frequency search window are selected. A new PRF is determined based on the ratio of the initial search window to the first PRF. The radar data of the first pair of PRF's is used to determine two modulo Doppler estimates. The modulo Doppler estimates are used to determine a new Doppler estimate with a confidence interval smaller than the first search window. The ratio of the new Doppler search window to the first PRF, is used to determine the next PRF. This process is iterated until the new Doppler search window is less than the first PRF.11-03-2011
20120032839CREATING AND PROCESSING UNIVERSAL RADAR WAVEFORMS - A new approach to radar imaging is described herein, in which radar pulses are transmitted with an uneven sampling scheme and subsequently processed with novel algorithms to produce images of equivalent resolution and quality as standard images produced using standard synthetic aperture radar (SAR) waveforms and processing techniques. The radar data collected with these waveforms can be used to create many other useful products such as moving target indication (MTI) and high resolution terrain information (HRTI). The waveform and the correction algorithms described herein allow the algorithms of these other radar products to take advantage of the quality Doppler resolution.02-09-2012
20100207808Method for processing TOPS (Terrain Observation by Progressive Scan)-SAR (Synthetic Aperture Radar)-Raw Data - Sub-aperture processing is carried out. Within each sub-aperture, range compression and a correction for the target range variation are carried out. Baseband azimuth scaling is used for processing the azimuth signal, wherein a long azimuth reference function and thus a wide azimuth dimension are prevented. The scaling range is not constant and depends on the range, which is not equal to the original range vector. It is calculated such that, in combination with a subsequent derotation step, constant azimuth scanning is achieved for all ranges. The selected derotation function, which is applied in the azimuth time domain, makes it possible for all the targets to be in base band, in this way varying the effective chirp rate. Since the phase is purely quadratic because of the azimuth scaling step, it is thus possible to use an optimal filter which takes account of the effective chirp rate. IFFT results in a focused image, and a final phase function in the time domain allows phase maintenance. Application for SAR, SONAR and seismic raw data processing in the TOPS mode, as well as other modes which make use of the antenna polar diagram being scanned in the azimuth and/or elevation direction.08-19-2010
20090109086High-Resolution Synthetic Aperture Side View Radar System Used By Means of Digital Beamforming - The transmission antenna (04-30-2009
20090033549Application of time reversal to synthetic aperture imaging - A method and apparatus for target focusing and ghost image removal in synthetic aperture radar (SAR) is disclosed. Conventional SAR is not designed for imaging targets in a rich scattering environment. In this case, ghost images due to secondary reflections appear in the SAR images. We demonstrate, how, from a rough estimate of the target location obtained from a conventional SAR image and using time reversal, time reversal techniques can be applied to SAR to focus on the target with improved resolution, and reduce or remove ghost images.02-05-2009
20100013700ACTIVE TRANSPONDER, PARTICULARLY FOR SYNTHETIC APERTURE RADAR, OR SAR, SYSTEMS - The invention concerns an active transponder, particularly for synthetic aperture radar systems, or SAR, comprising: a receiving antenna (01-21-2010
20110148691Distributed Sensor SAR Processing System - According to one embodiment, a synthetic aperture radar (SAR) processing system includes multiple radar receivers and a corresponding multiple location determining devices communicating with a SAR processor. The SAR processor receives return envelopes from each radar receiver indicative of electro-magnetic energy reflected from a target of interest. The SAR processor also receives, from multiple location determining devices that are each configured with each radar receiver, a location signal representing the position of its associated radar receiver, and generates imagery of the target according to the received envelopes and the position associated with each received envelope.06-23-2011
20110210885System and method for target signature calculation and recognition - The present invention is directed to a system and method for the identification of a target object in PCL radar applications. The disclosed embodiments describe the systems and methods used in the identification of a target object from the collection of data representing specific target object features, such as velocity, altitude, fuselage length, wing length, or wing sweepback angle, and the comparison of selected target object features with a database of known aircraft features. The present invention also provides for the calculation of feature dimensions, such as the fuselage length, wing length, or wing sweepback angle from measurements associated with a peak signal lobe as a function of a bistatic aspect angle.09-01-2011
20110175771Synthetic Aperture Radar Hybrid-Quadrature-Polarity Method and Architecture for Obtaining the Stokes Parameters of Radar Backscatter - A synthetic aperture radar hybrid-quadrature-polarity method and architecture comprising transmitting both left and right circular polarizations (by alternately driving, at the minimum (Nyquist) sampling rate, orthogonal linear feeds simultaneously by two identical waveforms, +/−90° out of phase), and receiving two orthogonal linear polarizations, coherently. Once calibrated, the single-look complex amplitude data are sufficient to form all Stokes parameters, which fully characterize the radar backscatter.07-21-2011
20100283669Multi-mode ground surveillance airborne radar - Ground surveillance airborne radar device, characterized in that it reproduces a mapping of STRIPMAP type of an area of interest divided into bands (11-11-2010
20110133983Methods for two-dimensional autofocus in high resolution radar systems - Provided are two-dimensional autofocus methods in a synthetic aperture radar (SAR) system which include: (1) two-dimensional pulse pair product algorithm including shear PGA, eigenvector phase history (“EPH”), shear PGA/EPH); (2) two-dimensional optimization algorithms including parametric one-dimensional estimate/two-dimensional correction, parametric two dimensional estimate/two-dimensional correction, unconstrained two-dimensional nonparametric and constrained two-dimensional nonparametric methods; (3) a two-dimensional geometry filter algorithm; (4) a two-dimensional prominent point processing algorithm; (5) a one-dimensional phase estimate of higher order two dimensional phase errors; and, (6) a fast SHARP parametric autofocus algorithm.06-09-2011
20090066562Beam phase modulation for improved synthetic aperture detection and estimation - Phase modulated beam patterns are substituted for the constant-phase versions that have been used in prior synthetic aperture systems. Relative movement between a radar/sonar/ultrasound platform and a point target causes a sequence of echoes from the point target to be phase and amplitude modulated by the beam pattern, as well as by the usual quadratic phase variation caused by range changes. Azimuth, range rate, and azimuth rate estimation, as well as detection in clutter, are substantially improved by appropriate beam pattern phase modulation, which is applied to the transmitter and/or receiver beam patterns. Phase modulated beam patterns are synthesized with array element weighting functions that are designed for high ambiguity function peak-to-sidelobe level, reduction of unwanted ambiguity ridge lines, and adequate spatial sampling. Two dimensional beam pattern phase modulation is useful when the relative motion between a transmit-receive array and multiple targets has both azimuth and elevation components.03-12-2009
20120206293METHOD AND SYSTEM FOR FORMING IMAGES BY COMPARING SUBSETS OF IMAGE DATA - A system and method for generating enhanced images of a target area using projection data obtained using an electromagnetic radiation source, the method comprising forming an initial aperture of data points containing positional information of the transmitter and receiver of the electromagnetic radiation; and an associated data record; randomly removing data points from the initial aperture to form subapertures with randomly missing data points; creating a subset of data points from each of the plurality of subapertures; the subsets containing data points containing image data for portions of the target area which are the same or overlapping; comparing the subsets of data points to determine variations in the data points indicative of transient data; based upon the comparison between overlapping subsets of image data, determining whether the subsets of data points comprise image data relating to physical objects or noise.08-16-2012
20090184865Method and system for automatic classification of objects - A new method has been developed as an attempt to improve speed and robustness of existing ISAR classification methods. The new method produces a set of silhouettes of possible models in a 3D model database. The set of silhouettes of each model views the model from various viewing angles, as the target dimensions will vary as it is viewed from different angles. The silhouettes are stored as a training set. Classification is done by comparing the silhouette of the target with the set of silhouettes in the training set. The silhouettes are calculated prior to the silhouette matching.07-23-2009
20090051587Synthetic aperture radar - A method of operating synthetic aperture radar in a low PRF mode, comprising generating a stream of radar pulses, imposing onto said stream a predetermined modulation of the Pulse Repetition Frequency (PRF), directing said stream to a target area, and processing received pulses, comprising separating the received pulses as a sequence of sets, and superposing received radar pulses of said sets, whereby to enhance the central received lobe and to attenuate side lobes.02-26-2009
20120001796Method and Device for Determining Aspect Angle Progression - A method and a device are provided for specifying, in the context of the image generation of ISAR processing, the determination of the aspect angle course subject to which the radar illuminates the vehicle during the exposure and subject to which the vehicle echoes are reflected back to the radar. Using the distance between the radar sensor and the vehicle as well as the change in distance, both of which are determined from the radar data, the position and the velocity of the vehicle are determined at any time during the exposure through linkage with available road information. The aspect angle is then determined from the positions of the sensor and of the vehicle as well as from the direction of movement of the vehicle. The required road information can be acquired from digital maps or images (e.g. aerial photographs, SAR-images).01-05-2012
20120001795Multipath SAR imaging - Disclosed is a method for removing the distortions produced by multipath Synthetic Aperture Radar (SAR) imaging. Conventional SAR systems assume that the returned signal consists of only direct scatterings; in practice however, the returned signal consists of multiple scattering events. Multiple or multipath scattering occurs when part of the surface reflects energy to at least one other part of the surface before the signal is scattered back to the receiver. Multipath scattering distorts the SAR image by superimposing blurring artifacts that diminish the resolution of the radar image. We exploit the phase change introduced by the “half Nyquist” frequency points of Fourier space to remove the effects of multiple scattering. The reflectivity function of the scene is recovered while retaining the resolving power of single scattering SAR.01-05-2012
20120119943METHOD AND APPARATUS FOR DETERMINING A DOPPLER CENTROID IN A SYNTHETIC APERTURE IMAGING SYSTEM - There is described a method for determining a Doppler centroid in a synthetic aperture imaging system, comprising: receiving raw data representative of electromagnetic signals reflected by a target area; selecting, among the raw data, at least two sets of sub-area data each representative of electromagnetic signals reflected by a corresponding sub-area of the target area, the sub-areas being substantially aligned along an azimuth axis of the target area and having a substantially identical surface area; for each one of the sets of sub-area data, generating an image corresponding to the corresponding sub-area; and measuring a mean intensity of the image; and estimating the Doppler centroid from a skew of an intensity function representing the mean intensity as a function of a look number for the corresponding sub-area.05-17-2012
20100245163STEP FREQUENCY ISAR - A step frequency inverse synthetic aperture radar (ISAR) includes a transmitter configured to transmit a transmission pulse at a transmission frequency to a near earth object (NEO), the transmission frequency having a frequency range comprising a starting frequency, an ending frequency, and a step size; a receiver configured to receive a pulse response from the NEO, the pulse response corresponding to the transmission pulse; and a computer configured to determine a 3-dimensional image of the interior of the NEO from the pulse response.09-30-2010
20080297405Synthetic Aperture focusing techniques - The present application describes an apparatus that includes a radar antenna device to acquire synthetic aperture radar data, radar receiver and transmitter equipment coupled to the radar antenna device, and a synthetic aperture radar processing device in communication with the radar receiver and transmitter equipment. This processing device includes a processor structured to process the synthetic aperture radar data, which is representative of a defocused image. The processor is further structured to define an image processing constraint corresponding to an image region expected to have a low radar return and generate one or more output signals as a function of the image processing constraint and the data. The one or more output signals are representative of a more focused form of the defocused image.12-04-2008
20120268318AUTOMATED LAYOUT OF BEAMS - The technology described herein includes a system and/or a method of automated layout of beams. The method includes generating a plurality of boundary positions along boundaries of an image frame. The method further includes determining a start location for a first beam within the plurality of boundary positions based on at least one of a mapping priority, direction of movement of a beam platform, and speed of movement of the beam platform. The method further includes modifying the plurality of boundary positions based on the start location. The method further includes determining a second location for a second beam within the modified plurality of boundary positions based on at least one of a mapping priority, direction of movement of a beam platform, and speed of movement of the beam platform. The method further includes modifying the modified plurality of boundary positions based on the second location.10-25-2012
20120286989TARGET IDENTIFICATION FOR A RADAR IMAGE - The target identification technology described herein includes a method, a system, and a computer program product. In some examples, the system includes a length estimation module configured to determine a length of a target from a radar image based on a range profile, the radar image, and one or more adaptive parameters. The system can include a points of interest module configured to identify at least one point of interest of the target from the radar image based on the length of the target, the range profile, the radar image, the one or more adaptive parameters, and Hough Line processing. The system can include an identification module configured to determine a target identification from a plurality of identification classes based on the length of the target and the at least one point of interest of the target.11-15-2012
20100149024Methods for two-dimensional autofocus in high resolution radar systems - Provided are two-dimensional autofocus methods in a synthetic aperture radar (SAR) system which include: (1) two-dimensional pulse pair product algorithm including shear PGA, eigenvector phase history (“EPH”), shear PGA/EPH); (2) two-dimensional optimization algorithms including parametric one-dimensional estimate/two-dimensional correction, parametric two dimensional estimate/two-dimensional correction, unconstrained two-dimensional nonparametric and constrained two-dimensional nonparametric methods; (3) a two-dimensional geometry filter algorithm; (4) a two-dimensional prominent point processing algorithm; (5) a one-dimensional phase estimate of higher order two dimensional phase errors; and, (6) a fast SHARP parametric autofocus algorithm.06-17-2010
20080231504METHOD AND APPARATUS FOR PROCESSING COMPLEX INTERFEROMETRIC SAR DATA - A computer system for processing interferometric synthetic aperture radar (SAP) images includes a database for storing SAR images to be processed, and a processor for processing interferometric SAR images from the database. The processing includes receiving first and second complex SAR data sets of a same scene, with the second complex SAR data set being offset in phase with respect to the first complex SAR data set. Each complex SAR data set includes a plurality of pixels. An interferogram is formed based on the first and second complex SAR data sets for providing a phase difference therebetween. A complex anisotropic diffusion algorithm is applied to the interferogram. The interferogram includes a real and an imaginary part for each pixel. A shock filter is applied to the interferogram. The processing further includes performing a two-dimensional variational phase unwrapping on the interferogram after application of the shock filter.09-25-2008
20080231503METHOD AND APPARATUS FOR COMPRESSION OF SAR IMAGES - A computer system for compressing synthetic aperture radar (SAR) images includes a database for storing SAR images to be compressed, and a processor for compressing a SAR image from the database. The compressing includes applying an anisotropic diffusion algorithm to the SAR image, and compressing the SAR image after applying the anisotropic diffusion algorithm thereto. Applying the anisotropic diffusion algorithm includes determining noise in the SAR, selecting a noise threshold for the SAR image based on the determined noise, and mathematically adjusting the anisotropic diffusion algorithm based on the selected noise threshold.09-25-2008
20080231502METHOD AND APPARATUS FOR PROCESSING SAR IMAGES BASED ON AN ANISOTROPIC DIFFUSION FILTERING ALGORITHM - A computer system for processing synthetic aperture radar (SAR) images includes a database for storing SAR images to be processed, and a processor for processing a SAR image from the database. The processing includes determining noise in a SAR image to be processed, selecting a noise threshold for the SAR image based on the determined noise, and mathematically adjusting an anisotropic diffusion algorithm based on the selected noise threshold. The adjusted anisotropic diffusion algorithm is applied to the SAR image.09-25-2008
20130176167WAVEFRONT COMPENSATION IN OPTICAL SYNTHETIC APERTURE IMAGING PROCESSORS - There is provided a System and method of wavefront compensation in a synthetic aperture imaging system. A return signal data representative of a signal reflected by a target area to be imaged is received. A compensation phase figure corresponding to a wavefront compensation to be applied is provided. The compensation phase figure is added or otherwise applied to the phase pattern of the return signal data in order to obtain a compensated phase pattern. An optical beam is spatially modulated according to the compensated phase pattern to produce a modulated optical beam such that the compensation phase figure produces a wavefront compensation on the optical beam. An image of the target area is optically generated using the modulated optical beam.07-11-2013
20130141273IMAGE PROCESSING METHOD - An image processing method using an algorithm which incorporates simulated annealing by parallel Markov chains, the calculation of fitness values of states of the Markov chains which have substantially the same simulated annealing temperature, the calculation of the standard deviation of these fitness values, and the use of this standard deviation in setting the simulated annealing cooling schedule. The method may be used to delineate an object of interest in an image against a background by estimating the boundary of the object and optimising the fit of the region within this boundary to the region occupied by the object.06-06-2013
20090121926MULTI-SPOT INVERSE SYNTHETIC APERTURE RADAR IMAGING - Providing multi-spot inverse synthetic aperture radar (ISAR) imagery is disclosed. Embodiments of techniques in accordance with the present disclosure may advantageously improve multiple target discrimination, detection, identification, and tracking using ISAR imaging. In an embodiment, an inverse synthetic aperture radar (ISAR) method for producing multiple ISAR images from a single waveform includes transmitting a chirp signal into a dwell surveyed by the antenna beamwidth. Multiple dechirp reference signals may be generated to demodulate return signals from the dwell at multiple selected intervals within a pulse repetition interval (PRI) to create demodulated signals.05-14-2009
20110267222LOCATION DETECTION METHODS AND SYSTEMS - This document discusses, among other things, target, e.g., a vehicle, detection methods and systems that can identify, track, and positionally locate the vehicle using passive sensing of stray signals emitted by a target. The detector can be handheld, in an example, with computing devices, interchangeable antenna units, and a display. The antenna can offer desired gain at specific frequencies of interest. The computing devices can determine the location of the target, e.g., vehicle, aircraft, to within one degree of accuracy. The display can provide this data to a user. In an example, the detector can be a standalone device. In an example, the detector is part of a system that includes a server that can receive data from a plurality of detectors and transmit instructions to the detectors.11-03-2011
20100141506FUNKBASIERTES ORTUNGSSYSTEM MIT SYNTHETISCHER APERTUR - The invention relates to a method for increasing the accuracy of a measurement of a radio-based locating system comprising a mobile station and at least one fixed station, wherein the movement of a mobile station from an initial position is detected by way of measuring data of an absolute sensor system and a relative sensor system, a virtual antenna is embodied in the form of synthetic aperture by way of measuring data and the mobile station is focused on the fixed station and/or vice versa by using the synthetic aperture.06-10-2010
20090179790SYSTEM AND METHOD FOR PROCESSING IMAGERY FROM SYNTHETIC APERTURE SYSTEMS - A method of processing a temporal sequence of base images from a synthetic aperture system such as a synthetic aperture radar is provided that simplifies the task of identifying moving objects. The method comprises the steps of firstly temporally filtering a plurality of the base images to form a reference image, and secondly normalising the reference image with a base image to form a change detection image. The change detection image has the property that all moving objects are emphasised. Further processing can optionally be performed on the change detection image to remove false targets based on characteristics of the highlighted areas or on a temporal track taken over a plurality of change detection images. The invention allows detection of moving objects without requiring a Doppler return from a target. The invention extends to a system adapted to implement the method, and a computer program.07-16-2009
20090128401SYSTEM AND METHOD FOR MONITORING TARGETS - A system comprising a moving radar, a processing device, and a phase difference determination device is used to monitor a target. The moving radar has first and second phase centers that transmit and receive signals normal to a direction of movement of the radar. The processing device receives first and second ones of the received signals from the first and second phase centers, respectively, and performs a target motion compensation and target acceleration correction for each of the first and second received signals to produce first and second images. The phase difference determination device determines a phase difference image from a comparison of the first and second images.05-21-2009
20100141507Radar device for maritime surveillance - The present invention relates to a radar device for maritime surveillance, intended to be installed on a vehicle moving at very high altitude, generally on a satellite.06-10-2010
20090278732Method and apparatus for simultaneous synthetic aperture radar and moving target indication - Method and apparatus for simultaneous synthetic aperture radar and moving target detection. A plurality of independent radio frequency signals are generated and applied to separate radiating/receiving antenna elements. Signals are generated as basis functions, such that moving target detection and synthetic aperture radar signals are constructed from individual waveform components in space, time, frequency, and coding. Waveform components are sorted and combined at reception. Received data is simultaneously processed to extract synthetic aperture radar images and moving target indication detections.11-12-2009
20080204311SYNTHETIC APERTURE RADAR AND PROCESSING METHOD OF REPRODUCING SYNTHETIC APERTURE RADAR IMAGE - A synthetic aperture radar to provide high resolution in the azimuth direction under the predetermined conditions of wide observation swathwidth in the range direction, stripmap observation and free PRF (Pulse Repetition Frequency) comprises a transmission antenna 08-28-2008
20120146846Method and apparatus for simultaneous synthetic aperture radar and moving target indication - Method and apparatus for simultaneous synthetic aperture radar and moving target detection. A plurality of independent radio frequency signals are generated and applied to separate radiating, receiving antenna elements. Signals are generated as basis functions, such that moving target detection and synthetic aperture radar signals are constructed from individual waveform components in space, time, frequency, and coding. Waveform components are sorted and combined at reception. Received data is simultaneously processed to extract synthetic aperture radar images and moving target indication detections.06-14-2012
20120056780Method and apparatus for simultaneous synthetic aperture radar and moving target indication - Method and apparatus for simultaneous synthetic aperture radar and moving target detection. A plurality, of independent radio frequency signals are generated and applied to separate radiating/receiving antenna elements. Signals are generated as basis functions, such that moving target detection and synthetic aperture radar signals are constructed from individual waveform components in space, time, frequency, and coding. Waveform components are sorted and combined at reception. Received data is simultaneously processed to extract synthetic aperture radar images and moving target indication detections.03-08-2012
20130009807Apparatus & Method for Short Dwell Inverse Synthetic Aperture Radar (ISAR) Imaging of Turning Moving Vehicles - An apparatus and method for generating a radar image including acquiring a first plurality of data in a first domain, wherein one or more of the first plurality of data include data of a moving target engaged in a turning motion at a rotational rate greater than a threshold; converting the first plurality of data from the first domain to a second plurality of data in a second domain, wherein the second domain is a first two-dimensional transformation of the first domain; extracting one or more of the second plurality of data; converting the one or more of the extracted second plurality of data to a third plurality of data in a third domain, wherein the third domain is a second two-dimensional transformation of the second domain; phase compensating the third plurality of data; and transforming the phase compensated third plurality of data to generate the radar image.01-10-2013
20120013502SYSTEM AND METHOD FOR PHASE RETRIEVAL FOR RADIO TELESCOPE AND ANTENNA CONTROL - Disclosed herein are systems, methods, and non-transitory computer-readable storage media for radio phase retrieval. A system practicing the method gathers first data from radio waves associated with an object observed via a first aperture, gathers second data from radio waves associated with the object observed via an introduced second aperture associated with the first aperture, generates reduced noise data by incoherently subtracting the second data from the first data, and performs phase retrieval for the radio waves by modeling the reduced noise data using a single Fourier transform. The first and second apertures are at different positions, such as side by side. This approach can include determining a value Q which represents a ratio of wavelength times a focal ratio divided by pixel spacing. This information can be used to accurately measure and correct alignment errors or other optical system flaws in the apertures.01-19-2012
20080224923METHOD AND APPARATUS FOR DETECTION OF MOVING OBJECTS BY SAR IMAGES - A method for the detection of moving objects by SAR images envisages the steps of: generating a pulse-repetition frequency signal starting from a radar signal; and generating a sequence of SAR images starting from the pulse-repetition frequency signal. In particular, SAR images with low azimuth resolution are generated by of coherent integration of the pulse-repetition frequency signal for a sub-aperture time shorter than an aperture time. In addition, the method envisages generating difference images through point-to-point difference between subsequent low azimuth resolution SAR images, and recognizing patterns associated to moving objects in the difference images.09-18-2008
20080303712Radar imaging system and method using directional gradient magnitude second moment spatial variance detection - A detection system and method. The inventive system includes an arrangement for receiving a frame of image data; an arrangement for performing a rate of change of variance calculation with respect to at least one pixel in said frame of image data; and an arrangement for comparing said calculated rate of change of variance with a predetermined threshold to provide output data. In the illustrative embodiment, the frame of image data includes a range/Doppler matrix of N down range samples and M cross range samples. In this embodiment, the arrangement for performing a rate of change of variance calculation includes an arrangement for calculating a rate of change of variance over an N×M window within the range/Doppler matrix. The arrangement for performing a rate of change of variance calculation includes an arrangement for identifying a change in a standard deviation of a small, localized sampling of cells. In accordance with the invention, the arrangement for performing a rate of change of variance calculation outputs a rate of change of variance pixel map.12-11-2008

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