A range-variant channel-calibration algorithm for the multi-channel in azimuth HRWS SAR imaging

For a multi-channel in azimuth high-resolution and wide-swath SAR (HRWS) system, the range-variant channel mismatch in amplitude and phase deteriorates the coherence between different channels and the Doppler ambiguity suppression. In this paper, in order to improve the performance of multi-channel reconstruction in azimuth, the range-variant channel mismatch is compensated by coarse-compensation and fine-compensation. Then, the post-Doppler beam-forming algorithm is adopted to reconstruct the azimuth un-ambiguity signal. The airborne ScanSAR real data is utilized to demonstrate the performance of the channel-calibration method.