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.

Disclosed is a calibration method of performing dual radiometric compensation by using an antenna gain pattern of a synthetic aperture radar (SAR) both in a time domain and in a frequency domain. The method may include performing frequency-domain radiometric compensation in relation to an elevation angle and performing time-domain radiometric compensation in relation to a frequency to calibrate the antenna gain pattern.

There are provided: a high-accuracy factor calculator for calculating, by a high-accuracy computation method, a distance R from a moving platform to a pixel position (a, b) within an observation target corresponding to an predicted position (x.sub.t, y.sub.t) and a phase factor A when a determination processor determines that an error is out of an allowable range; and a low-accuracy factor calculator for calculating, by a computation method with lower accuracy than that of the high-accuracy factor calculator (e.g., a computation method using an approximation algorithm), a distance R from the moving platform to the pixel position (a, b) corresponding to the predicted position (x.sub.t, y.sub.t) within the observation target and a phase factor A when the determination processor determines that the error is within the allowable range.

Range-compressed data are determined by range-compressing echo data, and are set as first data to be decomposed by first decomposition. Starting from n=1, iteration is performed as follows. nth data to be decomposed are up-sampled. nth decomposition is performed on the up-sampled data. Dependency on slant ranges between a reference point and sub-apertures before and after synthesis is determined. nth azimuth-synthesized data are acquired by performing, according to the dependency on the slant ranges, nth azimuth synthesis on data acquired by the nth decomposition. The nth azimuth-synthesized data are set as (n+1)th data to be decomposed by (n+1)th decomposition. The n is increased by 1. A next iteration is performed until the n reaches a positive integer N greater than 1. A focused image is acquired by performing azimuth focusing on the Nth azimuth-synthesized data by BP.

A detection system includes a phased array antenna having unitary radiating elements, the system being suitable for, in each cycle, successively directing, by way of the successive application of a first and a second determined phase law to the electrical signals for supplying power to the array antenna, the antenna radiation towards a first target area (Z1), then a second target area (Z2), which is separate from the first target area (Z1), and determining an image of each target area (Z1) on the basis of the echoes received from each of the first and second target areas.

Millimeter (mm) waves, in comparison to microwaves, have short wavelengths and can penetrate to few centimeters inside the body. The embodiments herein provide a method and system for millimeter (mm) wave synthetic aperture radar (SAR) imaging for superficial implant monitoring. The mmWave SAR and consecutive an autofocusing SAR imaging are suitable for a superficial tissue and subsequent continuous implant monitoring due to their smaller form-factor and faster processing coupled with focused dielectric lens. Additionally, a limb topography is approximated for localization of implant region on interest (ROI) in the SAR amplitude image. Further, the method and system provide a bone implant monitoring in order to assess any unwanted mobility or dislocation of the implant, and thus bone health is a critical issue.

The present invention concerns a method for performing SAR acquisitions, which comprises performing, in a time division fashion, SAR acquisitions of areas of a swath of earth's surface by means of a SAR system carried by an air or space platform; wherein performing SAR acquisitions in a time division fashion includes contemporaneously acquiring, in each pulse repetition interval, a plurality of areas of the swath that are separated in azimuth; and wherein the areas acquired in T successive pulse repetition intervals form an azimuth-continuous portion of said swath, T being an integer greater than one.

An information processing system, comprising: a memory configured to store instructions; and one or more processors configured to execute the instructions to: acquire a displacement of a structure on a ground; acquire sensor information related to a surface of the structure; determine a surface layer state of the structure based on the sensor information; and output the displacement in an entire or partial region of the structure and the surface layer state in the entire or partial region of the structure.

A synthetic aperture radar (SAR) system includes a chirp pulse generation unit configured to generate chirp pulses with a frequency increasing with time, a data storage unit storing transmission data, a chirp pulse modulation unit configured to generate modulated chirp pulses by modulating the chirp pulses through phase shift keying according to at least one bit value of the transmission data, and a transceiver unit configured to convert the modulated chirp pulses into a radio signal and transmit the radio signal.

A satellite (140) for operation in orbit around the earth comprises an ADCS (131, FIG. 1) configured for mechanically steering the satellite in the azimuth direction to prolong a dwell time (1105), during which a selected target is visible from the satellite, as the satellite orbits over the target. A processor at the ground station may be configured to process raw SAR data from any of the satellites described here. The raw SAR data may be processed in a number of ways to provide image information including but not limited to forming multilook images, compiling video sequences and colour coding images.