MOCO for High-Resolution ScanSAR via Full-Aperture Processing

In this paper, a novel Doppler rate (DR) estimation-based two-dimensional (2-D) subaperture motion compensation (MOCO) approach is proposed for high-resolution scanning synthetic aperture radar (ScanSAR) mode. It can estimate space-variant phase errors in different subswaths simultaneously by exploiting data of multiple subswaths. High-resolution ScanSAR images, produced by full-aperture processing algorithm, are often defocused by uncompensated phase errors. As a result of the periodic gapped data in each subswath in ScanSAR mode, the performance of the commonly used stripmap MOCO approaches will be degraded or even not work when using full-aperture processing algorithm. The effectiveness of the proposed approach is demonstrated by an airborne ScanSAR real data set containing different types of terrain, with a high geometric resolution of about 3.5 m (mid or far range) or 5 m (near range) in azimuth working at C band.