一种新的斜视波束指向SAR信号处理方法

针对斜视波束指向合成孔径雷达(BS-SAR)信号时，存在距离向与方位向的强耦合性及方位频谱的模糊问题，提出了一种基于方位重采样的信号频谱处理方法．线性距离走动校正后对信号频谱进行方位向重新采样，将其完全等效为正侧视合成孔径雷达信号的频谱．针对斜视BS-SAR，将方位重采样与谱分析技术相结合，得到无模糊及方位空变的二维频谱；再采用传统的正侧视BS-SAR算法，实现对场景的聚焦．仿真实验表明，文中方法可以有效应用于斜视BS-SAR的数据处理中．

Novel signal processing approach for squint beam-steering SAR (BS-SAR)

Due to the severe coupling effect between range and azimuth and the aliasing in the azimuth-frequency domain, it is difficult to deal with the squint Beam-Steering Synthetic Aperture Radar (BS-SAR) signal. Although the linear range walk correction can decrease the coupling effect dramatically, it leads to azimuth-variation into the Doppler frequency modulation (FM) rate and range cell migration (RCM). In order to eliminate the azimuth-variation, a novel spectrum processing approach based on azimuth resampling is proposed in this paper. After the linear range walk correction, the azimuth resampling is carried out in the azimuth-frequency domain and the signal’s spectrum will be completely equivalent to the broadside SAR configuration. For squint BS-SAR, the resampling is combined with the SPECAN technique. So the squint BS-SAR signal’s spectrum without aliasing and azimuth-variation can be obtained. Then the signal can be focused by the broadside BS-SAR imaging algorithm. Simulation results show that the proposed approach can be used to process squint BS-SAR data effectively.