Range migration correction of translational variant bistatic forward-looking SAR based on iterative keystone transformation

In the imaging processing of translational variant bistatic forward-looking SAR (TV-BFSAR), range cell migration correction (RCMC) is an essential procedure. Based on the azimuth variance property of the range cell migration (RCM), the keystone transformation is used for RCMC in TV-BFSAR. Before the RCMC, the ambiguity correction of the Doppler frequency must be done. However, the motion error makes the ambiguity correction hard to be realized. An iterative RCMC based on Keystone transformation scheme is proposed in this paper to overcome the challenge motion error. By searching for the correct Doppler ambiguity number based on the minimum entropy, this scheme corrects the RCM in TV-BFSAR. Simulations validate the effectiveness of this method.