G01S13/9054

METHOD AND SYSTEM FOR SYNTHETIC APERTURE RADAR SIGNAL PROCESSING
20190227162 · 2019-07-25 · ·

A method for synthetic aperture radar signal processing includes storing signal responses of a radar signal in a memory buffer, wherein the stored signal responses are represented by a two-dimensional signal in an azimuth dimension and a range dimension. The method further includes frequency filtering the two-dimensional signal in the azimuth dimension. In addition, the method includes applying a Fourier transformation to the frequency filtered signal in the range dimension. The method further includes generating a synthetic aperture radar image based on the Fourier transformed frequency filtered signal.

SAR Imaging Method for Interferometric Analyses

A SAR imaging method for interferometric analyses is provided, including: receiving raw SAR data related to two or more SAR acquisitions of one and the same area of the earth's surface carried out by one or more synthetic aperture radars; and processing the raw SAR data to generate SAR images. For each SAR acquisition, the respective raw SAR data is processed based on two different sets of processing parameters: a first set that is the same for all the SAR acquisitions and which comprises focusing Doppler parameters computed based on physical Doppler parameters related to all the SAR acquisitions; and a second set which comprises respective radiometric equalization Doppler parameters related to the SAR acquisition and computed based on respective physical Doppler parameters related to the SAR acquisition. Processing includes: focusing the raw SAR data related to all SAR acquisitions based on the focusing Doppler parameters and, for each SAR acquisition, applying a respective radiometric equalization, based on the respective radiometric equalization Doppler parameters, to the respective SAR data to compensate for possible differences in pointing of the synthetic aperture radar(s), without degrading azimuth resolution and without introducing radiometric distortions.

CROP CLASSIFICATION AND GROWTH TRACKING WITH SYNTHETIC APERTURE RADAR

A computer-implemented method executed by one or more satellites for assessing crop development by using synthetic aperture radar (SAR) is presented. The method includes generating SAR images from scanning fields including crops, monitoring grown of the crops within the fields during a predetermined time period, and estimating a height of the crops during the predetermined time period by using interferometric information from one or more of the SAR images and tracking change in height and growth rates. The method further includes differentiating between crops in different fields by monitoring changes in the height of the crops during an entire growing season.

Method 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.

Method and device for processing SAR raw data
12099114 · 2024-09-24 · ·

A method according to the present invention comprises the steps of: dividing SAR raw data into one or more sub-aperture data by a predetermined number in an azimuth direction; performing a spectral length extension FFT on the sub-aperture data in the azimuth direction; multiplying the sub-aperture data by a chirp scaling function; performing a range FFT on the sub-aperture data; performing range compression, SRC, and a bulk RCMC on the sub-aperture data; performing an inverse chirp-z transform on the sub-aperture data in a range direction; multiplying the divided sub-aperture data by a predetermined first function; performing an IFFT on the sub-aperture data in the azimuth direction; recombining the sub-aperture data; multiplying the recombined data by a second function and deramping same; performing an azimuth FFT on the recombined data; performing an azimuth IFFT on the recombined data; multiplying the recombined data by a third function and deramping same; performing the azimuth FFT on the recombined data; performing azimuth compression by multiplying the recombined data by a fourth function; performing an azimuth inverse chirp-z transform on the recombined data; and multiplying the recombined data by a fifth function for phase preservation.

PHASE HISTORY EXTRACTION FOR MOVING TARGET

A method for synthetic aperture radar (SAR) phase history extraction includes receiving, at a SAR system, a set of SAR phase history data derived from a plurality of return signals, the plurality of return signals produced by the SAR system illuminating a scene with a plurality of radar pulses. A region of interest (ROI) is obtained, the ROI corresponding to a moving target within the scene. A doppler shift frequency range for the moving target is determined based at least in part on an azimuth angle spread corresponding to the ROI and a known approximate trajectory of the moving target. The SAR phase history data is filtered to give extracted phase history corresponding to the moving target based at least in part on the doppler shift frequency range.

SYNTHETIC APERTURE RADAR USING ALTERNATING BEAMS AND ASSOCIATED METHODS

A synthetic aperture radar (SAR) for a flight vehicle may include an elongate phased array antenna oriented with a long axis in an elevation direction. The elevation direction is normal to a direction of flight of the flight vehicle. A transmitter is coupled to the elongate phased array antenna, and a receiver is coupled to the elongate phased array antenna. A controller is coupled to the transmitter and receiver and is configured to generate temporally alternating sets of receive beams for respective swaths to be used to form a SAR image across a surface below the flight vehicle. The same center frequency is used to create consistent SARs for all swaths, allowing for coherent combination between subsequent passes over the same swath.

Systems and Methods for Performing Synthetic Aperture Radar Imaging Using Superchirps
20180259639 · 2018-09-13 · ·

Synthetic aperture radar (SAR) imaging systems that transmit repeated waveforms based upon pseudonoise sequences to generate SAR imaging data in accordance with various embodiments of the invention are disclosed. A synthetic aperture radar in accordance with one embodiment of the invention includes: a transmitter configured to transmit superchirps, where the superchirp is generated by convolving a kernel with a pseudonoise modulated impulse sequence having a flat power spectrum; a receiver configured to receive backscatters of transmitted superchirps and digitize the received backscatters; and signal processing circuitry configured to perform matched filtering on digitized backscatters.

Method 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.

METHOD AND APPARATUS FOR COMPENSATING FOR A PARAMETER CHANGE IN A SYNTHETIC APERTURE IMAGING SYSTEM
20180113207 · 2018-04-26 ·

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.