A phase-preserving imaging algorithm for azimuth multi-channel spaceborne SAR data processing

Azimuth multi-channels is widely used for high-resolution and wide-swath recently, especially for the purpose of interferometry processing. However, due to the reconstruction of non-uniformly azimuth signal, the classical phase-preserving algorithm does not work well. In this paper, a phase-preserving imaging algorithm for azimuth multi-channel spaceborne SAR data processing is proposed. Firstly, combined with the reconstruction operation, the effect on phase-preserving accuracy is analyzed in detail, with the discussion of the equivalent phase center position. Then, the novel phase-preserving algorithm is addressed, which can accurately compensate the phase errors, including the constant phase term, the linear phase term introduced by the shifting zero-Doppler frequency, the residual cubic phase error along range direction, and the nonuniform sampling phase error after range-compression. Finally, simulation results verify the effectiveness of the proposed algorithm.