机载双站聚束合成孔径雷达的三维空间分辨特性

建立一般构型机载双站聚束合成孔径雷达(SAR)的通用几何模型,给出雷达回波信号的时频域表达式,以观测场景中心的目标回波为参考信号做差频处理,对得到的差分距离做泰勒展开,利用远场假设条件下的一阶近似推导出双站聚束SAR的三维空间分辨率公式。通过数值仿真验证了分辨率公式的正确性,并结合一种发射雷达平飞-接收雷达斜上飞的一般双站构型,分析了机载双站聚束SAR空间分辨特性随双站雷达空间构型及其运动参数的变化规律。

Three-dimensional spatial resolution of airborne bistatic spotlight SAR

A general geometry model of airborne bistatic spotlight SAR is firstly established, and the echo expression in time-frequency domain is presented. Secondly, the difference frequency processing is performed by using the echo of the imaging scene center as the reference. The difference distance obtained is expanded into Taylor series. Then, the three-dimensional spatial resolution of bistatic spotlight SAR is formulated by using the first-order approximation under far-field assumption. Theoretical results are illustrated by numerical simulations. Finally, based on a general bistatic configuration with the transmitter and the receiver flying along the horizontal direction and the sloping direction, the paper analyzes the variation rules of the spatial resolution following by the geometric configuration and the motion parameters.