Bistatic Forward-Looking SAR Imaging of Uniformly Moving Target Based on Improved BP Algorithm

Back projection (BP) algorithm is a common imaging algorithm that processes signals in the time domain. It can be used to create a clear image of a stationary target in the bistatic forward-looking synthetic aperture radar (BFSAR) system. However, when a target has a translational velocity or a complex rotation, the motion of the target causes additional range migration and time delay in the echo data. Hence, the BP algorithm cannot obtain high-resolution images of a maneuvering target. In this paper, a novel algorithm of SABP is proposed, which is an improved BP algorithm based on the simulated annealing algorithm (SAA) to image a uniformly moving target under the BFSAR model. First, the motion parameters of a moving target are linked with those of the BFSAR model through a mathematical derivation. Then, SAA is applied for estimating the motion parameters of the target, which are used to construct the phase compensated factor for the correction of time delay. Finally, the effectiveness of the proposed algorithm is substantiated by the comparisons of the simulation results between the traditional algorithms and the proposed algorithm.