G01S13/9058

Symmetrical multistatic radar constellation for earth observation
11231505 · 2022-01-25 · ·

A constellation of satellites and associated methods for Earth Observation are disclosed. One method includes transmitting a set of at least four signals towards the Earth using a constellation of at least four satellites and receiving a set of at least four reflected signals from the Earth using the constellation. The method also includes analyzing, using a set of at least four signal analyzers, the set of at least four signals to generate a set of data. Each satellite in the constellation individually houses a signal analyzer in the set of at least four signal analyzers. The method also includes deriving the set of Earth observations using the set of data. Each satellite receives a signal in the set of at least four signals from every other satellite in the constellation.

METHOD AND APPARATUS FOR SPACE-VARIANCE CORRECTION IMAGING OF BISTATIC SAR, DEVICE AND STORAGE MEDIUM

A method for space-variance correction imaging of BiSAR includes: motion parameters corresponding to a target point in an equivalent monostatic mode are calculated using a first motion trajectory, a second motion trajectory and an imaging parameter for focusing a radar echo signal, the target point at least including a center point of an imaging scene; azimuth Doppler center bias correction is performed on the radar echo signal by using the motion parameters corresponding to the center point; uniform and residual range cell migration correction is performed on a corrected signal, range blocking is performed, and range space-variance phase errors are corrected block by block; azimuth blocking is performed, and a corresponding number of filters are constructed for filtering processing; and inverse Doppler center bias correction is further performed to obtain a final imaging result graph.

Motion Extended Array Synthesis For Use in High Resolution Imaging Applications
20210341596 · 2021-11-04 · ·

A process and systems for constructing arbitrarily large virtual arrays using two or more collection platforms (e.g. AUX and MOV systems) having differing velocity vectors. Referred to as Motion Extended Array Synthesis (MXAS), the resultant imaging system is comprised of the collection of baselines that are created between the two collection systems as a function of time. Because of the unequal velocity vectors, the process yields a continuum of baselines over some range, which constitutes an offset imaging system (OIS) in that the baselines engendered are similar to those for a real aperture of the same size as that swept out by the relative motion, but which are offset by some (potentially very large) distance.

SATELLITE-FORMATION-BASED REMOTE SENSING SYSTEM AND CONSTELLATION SYSTEM
20220283295 · 2022-09-08 ·

The present invention relates a remote sensing system, or particularly a satellite-formation-based remote sensing system, wherein comprising: a master satellite provided with an SAR system as a payload thereof, a first concomitant satellite, and a second concomitant satellite, wherein the first concomitant satellite and the second concomitant satellite fly around the master satellite, and the master satellite is located on major axes of motion trajectories of the first concomitant satellite and the second concomitant satellite, so as to define a first spatial baseline and a second spatial baseline that have an identical cross-track baseline component. The present invention enables high-precision, wide-range, three-dimensional imaging based on the satellite-formation, while acquires spatiotemporal features of variation of a ground region according to the synchronization in terms of time, frequency, and space.

Object sensing from a potentially moving frame of reference with virtual apertures formed from sparse antenna arrays

In some examples, a first plurality of independent waveforms can be generated and converted into a first plurality of independent transmitted radar signals transmitted towards a field of view using a transmitter array comprising a first plurality of transmitter antennas. Further, a second plurality of receive radar signals to the first plurality of independent transmitted radar signals can be received from the field of view using a receiver array comprising a second plurality of receiver antennas. The second plurality of receive radar signals can be combined to form a combined receive radar signal and a representation of one or more areas of interest in the field of view can be provided using the combined receive radar signal. One or more attributes of the one or more areas of interest can be rendered using the representation of the one or more areas of interest.

Satellite tomography of rain and motion via synthetic aperture

The system and method represents a high-resolution, three-dimensional, multi-static precipitation RADAR approach that employs agile microsatellites, in formation and remotely coupled, via a new high-precision, ultra-low power, remote timing synchronization technology. This system and method uses multi-static RADAR interferometric methods implemented via a microsatellite formation to synthesize an effectively large (e.g., 15 m) aperture to provide about 1 km horizontal resolution and about 125 m vertical resolution in the Ku-band.

Radar imaging for antennas with clock ambiguities

A radar system for generating a radar image of a scene includes an input interface to accept radar measurements of a scene collected from a set of antennas with clock ambiguities, wherein the radar measurements are measurements of reflections of a radar pulse transmitted to the scene, a hardware processor configured to solve a convex sparse recovery problem to produce a radar image of the scene, wherein the convex sparse recovery problem matches a time shift of the radar measurements with a signal generated by propagation of the radar pulse through a radar propagation function of the scene, wherein the time shift of the radar measurements is represented as a convolution of the radar measurements with a shift kernel that is one-sparse in time, and an output interface configured to render the radar image.

Synthetic aperture radar signal analysis device, synthetic aperture radar signal analysis method, and synthetic aperture radar signal analysis program
11835619 · 2023-12-05 ·

A synthetic aperture radar signal analysis device 20 includes: an extraction unit 21 that extracts a stable reflection point from time-series data acquired through observation, by a synthetic aperture radar, of a region to be observed from a predetermined observing direction; a generation unit 22 that generates a cluster which is a collection of stable reflection points on the basis of the extracted stable reflection point corresponding to the predetermined observing direction; an association unit 23 that associates the generated cluster corresponding to the predetermined observing direction with a structure indicated by map data corresponding to the region to be observed; and a synthesis unit 24 that performs vector-synthesis of displacement rates for a plurality of the clusters each corresponding to the observing direction associated with the structure.

Bistatic interferometric terrestrial radar with transponder

Bistatic interferometric terrestrial radar comprising: a main radar unit (2) provided with ground fixing means (6) and provided with at least one transmitting unit (3) and at least one receiving unit (4); at least one amplifier transponder (5, 50) placed far away from said main unit (2), provided with ground fixing means (9) and provided with a receiving antenna (7) and a transmitting antenna (11).

SYNTHETIC APERTURE RADAR SIGNAL ANALYSIS DEVICE, SYNTHETIC APERTURE RADAR SIGNAL ANALYSIS METHOD, AND SYNTHETIC APERTURE RADAR SIGNAL ANALYSIS PROGRAM
20210223389 · 2021-07-22 · ·

A synthetic aperture radar signal analysis device 20 includes: an extraction unit 21 that extracts a stable reflection point from time-series data acquired through observation, by a synthetic aperture radar, of a region to be observed from a predetermined observing direction; a generation unit 22 that generates a cluster which is a collection of stable reflection points on the basis of the extracted stable reflection point corresponding to the predetermined observing direction; an association unit 23 that associates the generated cluster corresponding to the predetermined observing direction with a structure indicated by map data corresponding to the region to be observed; and a synthesis unit 24 that performs vector-synthesis of displacement rates for a plurality of the clusters each corresponding to the observing direction associated with the structure.