星载聚束式SAR回波信号快速仿真研究

Fast Echo Simulation Research for Spaceborne Spotlight SAR

基于Chialinwu提出的SAR的回波信号模型㈨，提出了一种星载聚束式SAR回波的快速仿真方法。该方法应用FFT快速产生dechirp处理前的雷达回波信号，再进行dechirp处理，并通过距离谱滤波，以避免成像处理时出现距离谱混迭现象，然后进行欠采样，产生聚束式SAR回波信号。与常规的直接仿真方法相比，该方法计算量很小且点目标数量对计算量影响很小，适用于高分辨率星载聚束式多点目标或面目标回波信号的仿真。最后，通过计算机仿真，给出了成像处理结果，并验证了该仿真方法的有效性。

Based on the SAR echo signal model presented by Chialin Wu, a fast echo simulation method for spacebome spotlight SAR was presented. Firstly, radar echo before dechirping was generated by FFT transform, then echo was dechirped. In order to avoid range alias during imaging, range spectrum filter was applied . Finally, spotlight SAR echo signal ,sas generated by downsampling. The validity of the simulation method was tested by computer simulation. Comparing with the normal direct simulation method, the method isn＇t affected by the number of point targets basically. So it is suitable for the simulation of multiple point targets and planar targets.