Automatic Correction of Range Migration in SAR Imaging

A new technique is developed for the automatic correction of range migration in synthetic aperture radar imaging. In the range-Doppler domain, samples at a Doppler frequency constitute a Doppler slice. It is noted that, when there is no range migration, the Doppler slices have similar envelopes, i.e., the envelope of one Doppler slice roughly equals the envelope of another Doppler slice multiplied by a constant. Thus, range migration can be corrected by shifting the Doppler slices such that their envelopes are similar. The technique applies even when the radar moves irregularly or the target is moving.