一种新的斜视波束指向SAR信号处理方法

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

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.

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 .