Systems and methods according to one or more embodiments are provided for registration of synthetic aperture range profile data to aid in SAR-based navigation. In one example, a SAR-based navigation system includes a memory comprising a plurality of executable instructions. The SAR-based navigation system further includes a processor adapted to receive range profile data associated with observed views of a scene, compare the range profile data to a template range profile data of the scene, and estimate registration parameters associated with the range profile data relative to the template range profile data to determine a deviation from the template range profile data.

A method of determining feasible swaths of a synthetic aperture radar (SAR) includes determining a first plurality of swaths that are transmit-feasible and nadir-feasible, determining a second plurality of swaths of the first plurality of swaths that satisfy at least one hard constraint, the at least one hard constraint being an image quality constraint or a system constraint, and generating a graph of the second plurality of swaths. The method may include assigning each feasible swath of the second plurality of swaths to a node in a directed graph, and adding a directed edge in the directed graph when a pair of swaths of the second plurality of swaths satisfy one or more defined constraints. The method may include configuring the SAR to operate based at least in part on the generated graph of the second plurality of swaths. Operating the configured SAR may include obtaining SAR images.

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.

Described is a method for extraction of a region of interest (ROI) from a composite synthetic aperture radar (SAR) phase history data. The method comprising receiving, with a system comprising a processor, the composite SAR phase history data of a plurality of backscattered return signals produced by a SAR system illuminating a scene with a SAR beam. The method also comprises obtaining a location of a first ROI within the scene and extracting from the composite SAR phase history data a first component SAR phase history data corresponding to the ROI at the location of the ROI.

A method of determining feasible swaths of a synthetic aperture radar (SAR) includes determining a first plurality of swaths that are transmit-feasible and nadir-feasible, determining a second plurality of swaths of the first plurality of swaths that satisfy at least one hard constraint, the at least one hard constraint being an image quality constraint or a system constraint, and generating a graph of the second plurality of swaths. The method may include assigning each feasible swath of the second plurality of swaths to a node in a directed graph, and adding a directed edge in the directed graph when a pair of swaths of the second plurality of swaths satisfy one or more defined constraints. The method may include configuring the SAR to operate based at least in part on the generated graph of the second plurality of swaths. Operating the configured SAR may include obtaining SAR images.

Systems and methods according to one or more embodiments are provided for mapping and registration of synthetic aperture raw radar data to aid in SAR-based navigation. In one example, a SAR-based navigation system includes a memory including executable instructions and a processor adapted to receive phase history data associated with observation views of a scene. The processor further converts the received phase history data associated with the observation views to a range profile of the scene. The range profile is compared to a range profile template of the scene to estimate a geometric transformation of the scene encoded in the received phase history data with respect to a reference template.

A synthetic aperture radar (SAR) system is disclosed. The SAR comprises a memory, a convolutional neural network (CNN), a machine-readable medium on the memory, and a machine-readable medium on the memory. The machine-readable medium storing instructions that, when executed by the CNN, cause the SAR system to perform operations. The operation comprises: receiving range profile data associated with observed views of a scene; concatenating the range profile data with a template range profile data of the scene; and estimating registration parameters associated with the range profile data relative to the template range profile data to determine a deviation from the template range profile data.

A multi-static synthetic aperture radar using beamformed illumination beams and multiple collection satellites is described. An illumination satellite may be in first orbit and multiple collection satellites may be in a second orbit. The illumination satellite may transmit beam signals (e.g., communication signals carrying modulated data to user terminals) from an antenna array to different beam coverage areas according to a beamforming matrix. Each of the collection satellites may receive reflections of the beam signals. The reflected signals received at the collection satellites may be processed according to the beam signals and beamforming matrix used to transmit the beam signals to obtain an image of a geographical area. In some cases, the collection satellites may relay the received signals for processing via the illumination satellite.

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.

A method for detecting a horizontally buried linear object is provided, the horizontally buried linear object having a longitudinal extension. The method comprises moving, with a flying platform comprising a radar for synthetic aperture radar, SAR, vertical imaging, along a trajectory corresponding to a synthetic aperture. The method further comprises transmitting and receiving radar signals while moving along the trajectory corresponding to the synthetic aperture. The method also comprises forming a SAR image based on collected data representing radar signal reflections received from the ground. The method additionally comprises detecting one or more features in the formed SAR image relating to the horizontally buried linear object. Said trajectory is oriented in a direction substantially perpendicular to an expected orientation of the longitudinal extension of the horizontally buried object and traversing the horizontally buried object.