一静一动双基地SAR改进非线性CS算法

Improved NLCS Imaging Algorithm of Bistatic SAR with a Stationary Receiver

本文基于双基地一站固定(接收机固定)的特殊模式,首先建立了在该模式下双基地SAR的几何构型和信号模型;然后根据该模式的几何特点,分析了斜视情况下高次相位和调频率空变性对距离向聚焦的影响,考虑到利用驻定相位原理将信号从二维频域转换到距离多普勒域时二次模型的失效,引入了三次模型实现了距离向三次相位的补偿,其后通过距离多普勒域二次和三次扰动函数的相乘,并将距离向调频率在参考点进行展开,实现了距离向的聚焦和距离徙动的校正改进,并给出了距离向校正函数的解析表达式;最后,通过仿真和实测数据的处理验证了校正函数的正确性。

This paper is based on the special mode of a stational7 receiver configuration in Bistatic Synthetic Aperture Ra- dar, and firstly established the basic system geometrical model and signal model, Secondly, Based on the geometric charac- ter,two main problems, i.e. spatial variance of the FM rate and cubic phase terms, were introduced in the image formation algorithm. In view of the quadratic model is invalid, when the principle of stationary phase is used to transfer signal from the 2-D frequency domain to Range-Doppler domain, this paper introduced a cubic model to realize the compensation of cubic phase in Range, then after muhiplying the quadratic and cubic perturbation function in Range-Doppler domain, the correc- tion of range cell migration and the focus in the range direction can be achieved by expanding FM rate at the referenc, e point,and the improved correction function is then deduced. Finally, con＇esponding simulated and real bistatic data are pro- cessed to support it.