A Novel Image Formation Algorithm for High-Resolution Wide-Swath Spaceborne SAR Using Compressed Sensing on Azimuth Displacement Phase Center Antenna

High-resolution wide-swath (HRWS) imaging with space- borne synthetic aperture radar (SAR) can be achieved by using az- imuth displacement phase center antenna (DPCA) technique. How- ever, it will consequently leads to extremely high data rate on satellite downlink system. A novel sparse sampling scheme based on compressed sensing (CS) theory for azimuth DPCA SAR was proposed, by which only a small proportion of radar echoes are utilized for imaging to re- duce data rate. The corresponding image formation algorithm for the proposed scheme was presented in the paper. The SAR echo signal of each channel can be reconstructed with high probability by using orthogonal matching pursuit (OMP) algorithm in Doppler frequency domain. The reconstructed echo signals of each channel are jointly processed by means of spectrum reconstructing fllter for compensat- ing Doppler spectrum aliasing resulting from non-uniform sampling in azimuth direction. The high quality SAR image can be obtained by us- ing chirp scaling algorithm. The efiectiveness of the proposed approach was validated by computer simulations using both point targets and distributed targets.