General Bistatic SAR Data Processing Based on Extended Nonlinear Chirp Scaling

General bistatic SAR (BiSAR) data are more challenging to process than their translational invariant counterparts because the transmitter and the receiver have unequal velocities or/and nonparallel tracks. Although several algorithms have been used to process the data in general cases, these can work only in small invariant regions of the azimuth-variant problem because of the complicated configurations. In this letter, an extended nonlinear chirp scaling (NLCS) is proposed to address this problem. The key is to use the vector analysis of the instantaneous slant ranges to extract the azimuth-variant components. Furthermore, a new perturbation function based on the principle of NLCS used to precompensate the data. The simulation results show that our algorithm can handle data with more complicated bistatic cases than the existing algorithms.