Phase history extraction for moving target

A synthetic aperture radar (SAR) system, comprising:

• a logic subsystem;
• and
• a storage subsystem holding instructions executable by the logic subsystem to:
• receive 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;
• obtain a region of interest (ROI) corresponding to a moving target within the scene;
• determine a doppler shift frequency range for the moving target based at least in part on an azimuth angle spread corresponding to the ROI and a known approximate trajectory of the moving target;
• filter the SAR phase history data to give extracted phase history corresponding to the moving target based at least in part on the doppler shift frequency range;
• and
• motion correct the extracted phase history to give a corrected phase history by applying a first motion correction to account for the known approximate trajectory of the moving target, and a second motion correction to account for unsteady trajectory perturbations of the moving target.

A method for synthetic aperture radar (SAR) phase history extraction, the method comprising:

• 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;
• obtaining a region of interest (ROI) corresponding to a moving target within the scene;
• determining a doppler shift frequency range for the moving target based at least in part on an azimuth angle spread corresponding to the ROI and a known approximate trajectory of the moving target;
• filtering the SAR phase history data to give extracted phase history corresponding to the moving target based at least in part on the doppler shift frequency range;
• motion correcting the extracted phase history to give a corrected phase history based at least in part on the known approximate trajectory of the moving target, wherein motion correcting the extracted phase history includes applying a fast time correction in which one or more of the plurality of return signals are time-shifted based at least in part on a perpendicular motion component of the moving target, and applying a slow time correction in which a time interval between two or more of the plurality of return signals is dilated or contracted based at least in part on a parallel motion component of the moving target;
• and
• providing the corrected phase history to an automatic target recognition (ATR) system configured to perform target recognition based on input phase history data.