Signal Separation in GEO SAR Imaging of Maneuvering Ships by Removing Micro-Motion Effect

Geosynchronous synthetic aperture radar system provides the capability of continuous observation for several hours, which is of great significance for ship monitoring. The complex motion of maneuvering ship during long integration time makes the signals of different targets interfere with each other, resulting in the micro-motion effect, which degrades the quality of the image. The micro-motion of the expected target is first compensated for by the generalized radon-Fourier transform based method. The key of the algorithm is to enlarge the range cell migration of the interfering target while maintaining the energy of the expected target in a range bin based on the Keystone transform (KT) and inverse KT. Combined with the L-statistics method, the proposed algorithm can separate signals effectively. Validation results based on simulation and airborne experiments show that the proposed algorithm achieves good signal separation performance.