An extended NLCS algorithm for Bistatic fixed-receiver SAR imaging

Imaging of Bistatic fixed-receiver SAR which is azimuth-dependent, is rather different from monostatic SAR, because the relative position between the transmitter and the receiver is slow-time dependent. In this paper, the Range Cell Migration (RCM) characteristics of Bistatic fixed-receiver SAR are analyzed firstly. Then the nonlinear chirp scaling (NLCS) algorithm is presented and the residual phases caused by the NLCS processing are analysed as well. An extended NLCS algorithm based on sub-aperture approach is proposed to handle the case in which the residual phases cannot be ignored for Bistatic fixed-receiver SAR. Finally, a simulation with typical parameters is performed to verify the correctness of the extended NLCS algorithm.