改进的基于时域距离走动校正的CS成像算法

摘要

该文考虑大斜视SAR距离徙动中3次距离偏移对信号特性的影响，提出一种改进的基于时域距离走动校正的CS成像算法。该算法首先在时域进行距离走动校正，然后通过CS变标处理和一致距离徙动校正实现场景所有目标的精确距离徙动校正，最后通过改进的方位匹配滤波方法实现清晰成像。该算法的整个成像处理过程只包含快速傅里叶变换和复乘运算，因此算法效率较高。仿真结果表明，改进后的算法明显改善了成像结果的方位向旁瓣特性，可以满足大斜视高分辨成像的要求。%In this paper, the effects on signal characteristic which caused by cubic range migration in high squint mode are considered, and a modified chirp scaling imaging algorithm is proposed. In this method, range walk is removed in time domain firstly, and range cell migrations of all targets in the imaging scene are corrected accurately by chirp scaling operation and the unified Range Cell Migration Correction (RCMC). Finally, a focused SAR image can be obtained after the modified azimuth filtering. The overall imaging procedure of the algorithm only involves fast Fourier transform and complex multiplication, which means higher efficiency. Simulation results show that the modified algorithm can greatly improve the azimuth side-lobe performance, which is a great advantage in the high resolution imaging in high squint mode.