Fast Interchannel Phase Error Estimation for Azimuth Multichannel ScanSAR

The azimuth multi-channel (AMC) scanned-beam synthetic aperture radar (ScanSAR) can achieve high resolution and ultrawide-swath imaging. An inter-channel phase error estimation method for AMC ScanSAR is studied in this paper. First, the signal is dechirped and coarse-focused in the range-Doppler domain. Second, a linear regression is applied to estimate the post-dechirp spectral folding number (PDSF-number). Finally, phase errors are estimated based on the PDSF-number and the focused peak values. The proposed method can accurately estimate the phase errors and restore the image quality with low computational cost and high robustness, which is verified by experiments.