宽波束角大测绘带UWB SAR的子孔径子带运动补偿算法  

An Improved Sub-aperture Sub-patch Motion Compensation Algorithm for UWB SAR

作　　者：薛国义[1] 周智敏[1] 赖涛[1] 

机构地区：[1]长沙国防科技大学电子科学与工程学院,长沙410073

出　　处：《宇航学报》2008年第3期1008-1014,1020,共8页Journal of Astronautics

摘　　要：VHF/UHF波段的正侧视条带式超宽带合成孔径雷达(UWB SAR)通常具有宽方位波束角和大处理测绘带特性,这些特点造成了雷达回波相位误差的距离空变和方位空变,使得传统的运动补偿算法失效。从载机视线误差对回波相位的影响出发,推导了一种在回波距离压缩后、距离迁徙校正前的子孔径子带补偿算法。通过将距离压缩后的回波沿距离向分块,沿方位向分子孔径,并将距离向和方位向的空变误差补偿紧密结合,提高了补偿效率。计算机点目标仿真结果,验证了该算法的有效性。文中还给出了子孔径和子带的划分原则及子孔径子带补偿算法与扩展ECS算法结合的方法。Ultra Wide-Band （UWB） Synthetic Aperture Radar （SAR） operating on UHF/VHF band with wide processing beam and wide processing swath produces space-variant phase errors and invalidate most conventional motion compensation algorithms. Based on the aircraft motion errors in line of sight （LOS） influence upon phase errors of SAR echoes, a new sub-aperture sub-patch motion compensation algorithms for real-time motion compensation is derived detailedly. The new algorithms combines second-order motion error correction caused by large swath and second-order motion error correction caused by wide beam tightly, improving computational efficiency and the compensation algorithms can be done before range cell migration correction （RCMC）, which will benefit RCMC of imaging algorithm in reverse. The effect of the new compensation algorithm is validated by simulation. The division principle of sub-aperture in azimuth and sub-patch in range is discussed in this paper, and the method incorporating the compensation method into extended ECS algorithm is studied also.

关 键 词：UWB SAR 宽波束角 大测绘带 运动补偿 子孔径 

分 类 号：TN958[电子电信—信号与信息处理]