Imaging Method of Spaceborne TOPS SAR Based on ECS and SPECAN

The terrain observation by progressive scans SAR (TOPS SAR) is a new working mode of spaceborne SAR. While maintaining the advantages of SCANSAR's wide mapping band, this working mode solves the scalloping effect and other problems. Aiming at the problem of azimuth spectrum aliasing of spaceborne TOPS SAR echo signals, this paper proposes a spaceborne TOPS SAR full aperture imaging algorithm based on ECs and SPECAN. First, the echo after range walk correction is SPECAN operated to obtain a two-dimensional spectrum without blur, and then the improved ECS algorithm is used for range migration correction and range pulse compression, Finally, azimuth defocusing and scaled Fourier transform (SCFT) are used to realize azimuth focusing. Simulation results show the effectiveness of the algorithm.