固定接收机双站UWB SAR改进NLCS算法

摘要

Based on the imaging feature of bistatic UWB SAR with a stationary receiver, the paper establishes a received signal model, analyzes the characteristic of range migration under such a configuration and then proposes an improved NLCS algorithm to mitigate the influence of the space warp of the range migration. The study places an emphasis on the analysis of changes of the FM rate with different azimuth positions. To solve the problem of azimuth focusing caused by the space warp of the FM rate, the paper introduces a extended NLCS algorithm, deduces the azimuth perturbation function of a higher precision and gives the specific procedure of the novel algorithm. Finally, the new algorithm is used to process the echoes of a point target in a bistatic UWB SAR system by computer simulation, and the effects of imaging and focusing of the target are better than the traditional algorithm.%针对固定接收机双基地UWB SAR成像特点,建立回波信号模型,分析了该构型下距离徙动特征,结合改进NLCS算法解决了距离徙动空变带来的影响.重点分析了方位向调频率随目标方位位置的变化情况,为了解决方位调频率空变影响方位聚焦的问题,提出了一种扩展NLCS算法,推导了更高精度的方位扰动函数的解析表达式,并给出了该算法的具体操作流程.最后用该方法对仿真的点目标双基回波进行成像处理,获得了较好的目标聚焦效果,验证了所提出方法的正确性.