①National Key Laboratory of Microwave Imaging Technology, Institute of Electronics, Chinese Academy of Sciences, Beijing 100080, China;②Graduate University of the Chinese Academy of Sciences, Beijing 100039, China
Abstract:This paper starts from a signal model of a stationary receiver configuration in airborne bistatic SAR systems which are characterized by spatially separated transmitters and receivers. Through analyzing the system geometrical characteristic, the range cell migration, the influence of the difference on the range cell migration and the change of the linear FM rate both in range and azimuth direction in RD field are discussed. And then a nonlinear perturbation function is deduced to equalize the targets’ FM rates in azimuth direction. After that, an imaging algorithm based on the CSA for bistatic SAR with a stationary receiver is get, and the distorted image is corrected. Finally the validity and the feasibility of dealing with big mapping zone of the algorithm proposed with this paper is supported with point target simulation experiments.