SAR signal based motion compensation through combining PGA and 2-D map drift

For synthetic aperture radar (SAR) operating in fine resolution mode, even with advanced motion measurement sensors, residual range cell migration (RCM) together with azimuth phase error considerably deteriorates the image quality. In this paper, a solution to SAR signal based motion compensation (SBMC) is presented, which combines the well-known techniques of phase gradient autofocus (PGA) and map drift (MD). The presented SBMC scheme employs subaperture processing, and compensates the residual RCM in the meantime of combining the subaperture phase error. Experimental results indicate the effectiveness of our approach.