高分辨率星载聚束式SAR改进的ECS成像算法

提出一种适用于高星载聚束式合成孔径雷达（SAR）的改进Extended Chirp Scaling（ECS）算法。基于斜视距离等效模型，推导出改进的ECS算法，给出改进的方位Scaling因了以及算法的实现步骤。在斜视情况下改进的方法Scaling因子可以减小算法所需要的方位时间展宽，提高方位处理效率。为解决高分辨率星载聚束式SAR脉冲重复频率（PRF）过高等问题，在算法中结合了子孔径处理，并分析了采用子孔径处理的必要性及其实现方法。最后，通过计算机仿真，验证了算法的有效性。

Refined ECS algorithm for high-resolution spaceborne spotlight SAR imaging

A refined extended chirp scaling (ECS) algorithm for high resolution spaceborne spotlight synthetic aperture radar (SAR) imaging was presented.The squinted range equivalent model was selected,which was fitter for spaceborne geometrical relation than the broadside range model.Based the squinted range equivalent model,complete derivation of the algorithm was presented.The refined azimuth scaling factors was given.The refined azimuth scaling factor deceased azimuth time expansion and improved efficiency of azimuth processing.Besides,a subaperture approach was introduced.The subaperture approach could decrease pulse repetition frequency (PRF) and data rate of spaceborne spotlight SAR.The necessity and implementation of the subaperture approach was analyzed in depth.Finally,the validity of the refined algorithm is tested by computer simulation.