Autofocusing of moving objects in SAR data based on adaptive notch filtering

This paper proposes a new autofocusing method for synthetic aperture radar (SAR) imaging of complex moving structures such as ships on the ocean. This method is well suited for linear uniform motion as well as for nonuniform motion that may be caused by ocean waves. The key step is a modified adaptive notch filter (ANF) that can retrieve phase modulation due to motion. Simulation examples and real SAR results are presented.