Bistatic forward-looking SAR imaging processing based on optimized NLCS algorithm

In bistatic forward-looking SAR, due to its special motion model, the inevitable non-ideal motion error is introduced into the radar echo signal. Resulting in unknown two-dimensional space-varying RCM and Doppler parameters in the target echo. This paper proposes an optimization based NLCS method. Firstly, the first-order RCM is corrected by the keystone transform. Then based on the minimum entropy criterion and the processing idea of NLCS algorithm, the problem of unknown space-varying bending correction and Doppler parameter equalization is transformed into a constrained optimization problem. The genetic algorithm is used to solve the optimal NLCS equilibrium parameters. Thereby achieving high-precision imaging processing of bistatic forward-looking SAR echoes.