G01S13/9076

Method and device for suppressing range ambiguity

A method and device for suppressing range ambiguity and a computer readable storage medium are provided. The method includes: determining a pulse timing relationship of a transmission signal; determining orthogonal nonlinear frequency modulation signals; modulating the transmission signal by using the orthogonal nonlinear frequency modulation signals; transmitting the modulated transmission signal according to the pulse timing relationship, and determining echo data of the modulated transmission signal; and generating an image according to a polarization scattering matrix for the echo data of the modulated transmission signal.

Synthetic aperture radar apparatus and methods

A synthetic aperture radar (SAR) system generates an image of a first swath. The SAR includes at least one SAR antenna, at least one SAR processor and at least one SAR transceiver. In operation the SAR defines a first beam to illuminate the first swath and one or more second beams to illuminate area(s) of ambiguity associated with the first beam. The SAR transmits a pulse via the first beam and receives backscatter energy. The SAR generates a first signal associated with the first beam and one or more second signals associated with the second beam(s). The second signal(s) are combined with determined complex vector(s), generating ambiguity signal(s) and the ambiguity signals are combined with the first signal to generate an image associated with the first swath.

Method and apparatus for performing dual polarization change detection using polarimetric synthetic aperture radar imagery

Apparatus and method configured to determine locations of man-made objects within synthetic aperture radar (SAR) imagery. The apparatus and method prescreen SAR imagery to identify potential locations of man-made objects within SAR imagery. The potential locations are processed using a change detector to remove locations of natural objects to produce a target image containing location of substantially only man-made objects.

Method and device for radar transmission and reception by dynamic change of polarization notably for the implementation of interleaved radar modes
11644532 · 2023-05-09 · ·

Method and device for radar transmission and reception by dynamic change of polarization notably for the implementation of interleaved radar modes are provided. A radar transmission-reception method and a device for implementing this method, the method alternatively implementing two modes of operation, a short range mode exploiting short pulses and a long range mode exploiting modulated long pulses, the method consisting, for each mode, in: producing two synchronous radiofrequency (RF) transmission signals having between them a phase-shift θ of controllable given value; radiating two radiofrequency waves, each corresponding to one of the transmission RF signals produced, by means of two colocated radiating sources each having a given polarization axis; handling the reception of the backscattered radiofrequency signals picked up by each of the radiating sources, and delivering two radiofrequency (RF) reception signals each corresponding to a radiofrequency signal picked up by one of the radiating sources, a phase-shift θ′ being applied between the two signals delivered, θ′ being able to be determined as being equal to θ.

METHOD AND SYSTEM FOR CREATING INTERFEROMETRIC COHERENCE DATA PRODUCTS FOR OBJECTS

A method for creating interferometric coherence data products for objects imaged by Synthetic Aperture Radar (SAR) having polarization(s). The method includes: for each identifiable object geometry for which there are acquired geocoded interferometric SAR images with flat-earth and topographic phase removed having following pixel values: backscatter intensity (V1) in polarization(s) for master image; backscatter intensity (V2) in polarization(s) for slave image; in-phase component (V3) of geocoded interferogram in polarization(s); and quadratic-phase component (V4) of geocoded interferogram polarization(s), determining which geocoded pixels are within identifiable object geometry considering known geolocation accuracy of identifiable object geometry and geocoded interferometric SAR images; and determining coherence values and statistics of coherence values for objects for polarization(s), based on pixel values V1, V2, V3, and V4 within identifiable object geometry.

Multi-channel split-swath (MCSS) synthetic aperture radar (SAR)

A synthetic aperture radar (SAR) generates concurrent first radar pulses in first frequency channels. The SAR transmits, and receives returns of, the concurrent first radar pulses by first antenna feeds that form first beams in the first frequency channels and that are directed to respective first subswaths of a swath on the Earth separated by subswath gaps. The SAR generates concurrent second radar pulses in second frequency channels. The SAR transmits, and receives returns of, the concurrent second radar pulses by second antenna feeds configured to form second beams in the second frequency channels and that are directed to respective second subswaths of the swath on the Earth and that coincide with the subswath gaps. The SAR processes the returns of the first radar pulses from the first subswaths and the returns of the second radar pulses from the second subswaths to form a SAR image contiguous across the swath.

SUBSURFACE IMAGING RADAR
20170299716 · 2017-10-19 ·

A method and system for obtaining SAR images with reduced or eliminated surface clutter to detect subsurface targets, the method comprising the following steps: -selecting a first frequency and an incidence angle for the radar signal such that the ratio of surface backscattering to subsurface target backscattering is significantly larger for vertical polarization than for horizontal -obtaining vertically and horizontally polarized SAR images based on the same SAR path exploiting the selected first frequency and viewing angle -weighting and differencing the vertically and horizontally polarized SAR images so that the surface backscattering completely cancels between the two images and only the combination of the target backscattering components remains.

Radio frequency life detection radar system

Trapped or confined individuals may be located and rescued by detecting their vital signs (e.g., chest movement or heart beat) using reflected, radio frequency signals over a range of multiple antenna polarities.

METHOD AND APPARATUS FOR PERFORMING DUAL POLARIZATION CHANGE DETECTION USING POLARIMETRIC SYNTHETIC APERTURE RADAR IMAGERY

Apparatus and method configured to determine locations of man-made objects within synthetic aperture radar (SAR) imagery. The apparatus and method prescreen SAR imagery to identify potential locations of man-made objects within SAR imagery. The potential locations are processed using a change detector to remove locations of natural objects to produce a target image containing location of substantially only man-made objects.

Multiple beam antenna for wide swath satellite based SAR

A radar antenna for a flight vehicle that follows a flight path comprises a radio frequency (RF) reflector, and separated first arrays of first RF feed elements to form, with the reflector, respective first fixed radar beams that are directed at the Earth and positionally offset with respect to each other, such that when the radar antenna follows the flight path, the respective first fixed radar beams trace respective first subswaths on the Earth that are separated from each other by respective subswath gaps.