Study on spectrum reconstruction algorithm for high resolution and wide swath space-borne SAR

The confliction between swath width and resolution in the routine space-borne SAR can be solved by Displaced Phase Centers multibeam in Azimuth with ScanSAR in across-track direction. However, the pulse repetition frequency (PRF), sensor velocity and antenna size underlie a stringent timing requirement and any deviation will result in a non-uniform sampling in space domain. The paper derives an innovative frequency domain reconstruction algorithm, which enables a recovery of the unambiguous Doppler spectrum also in case of a non-uniform sampling. The simulation results which illustrate the methods´ validities show that the paired echoes from the non-uniform sampling is suppressed to below -60dB and AASR is below -23dB.