CAJ | 학술논문

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。
해문고필대사시SAR거리사동중3차거리편이대신호특성적영향，제출일충개진적기우시역거리주동교정적CS성상산법。해산법수선재시역진행거리주동교정，연후통과CS변표처리화일치거리사동교정실현장경소유목표적정학거리사동교정，최후통과개진적방위필배려파방법실현청석성상。해산법적정개성상처리과정지포함쾌속부리협변환화복승운산，인차산법효솔교고。방진결과표명，개진후적산법명현개선료성상결과적방위향방판특성，가이만족대사시고분변성상적요구。
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.