采用斜距波数子带划分的SAR图像自聚焦方法  

SAR Autofocusing Method Based on Slant Range Wavenumber Subband Division

作　　者：马彦恒 褚丽娜 杨晓亮[2] 侯晓泽 MA Yanheng;CHU Lina;YANG Xiaoliang;HOU Xiaoze(Shijiazhuang Campus,Army Engineering University of PLA,Shijiazhuang 050003,China;The 54th Research Institute of China Electronics Technology Group Corporation,Shijiazhuang 050000,China)

机构地区：[1]陆军工程大学石家庄校区,河北石家庄050003 [2]中国电子科技集团第五十四研究所,河北石家庄050000

出　　处：《陆军工程大学学报》2022年第3期12-21,共10页Journal of Army Engineering University of PLA

基　　金：国防科技基金(2019-JCJQ-JJ-015);军内科研项目(KYSZJQZL2019)。

摘　　要：小型旋翼无人机载合成孔径雷达在运动中易受大气湍流等因素影响,产生二维空变的运动误差,影响SAR成像质量。本文提出一种基于拟极坐标系的快速因子分解反向投影(QPG-FFBP)成像自聚焦方法。该方法基于斜距波数子带划分,采用基于加权的相位梯度自聚焦模型估计每个子带的方位相位误差,并融合非系统距离单元徙动的相干性估计,完成全图像的运动补偿,解决二维空变误差补偿问题,提升图像的聚焦效果。通过仿真实验以及小型旋翼无人机载实测SAR数据验证了该方法的有效性。The small rotor unmanned aerial vehicle synthetic aperture radar(SRUAV SAR) is susceptible to atmospheric turbulence and other factors, which leads to 2-dimensional(2-D) space-variant motion errors and affects the quality of SAR imaging. This paper proposed a quasi-polar grid-based fast factorized back-projection(QPG FFBP) imaging autofocusing method. Based on the slant range wavenumber subband division, the azimuthal phase errors(APE) of each subband was estimated by weighed phase gradient autofocus(WPGA), and the non-systematic range cell migration(NsRCM) was estimated according to the coherence of APE and NsRCM. After fusion of the subband NsRCM, the NsRCM compensation of the whole image was completed, and the 2-D space-variant error compensation problem was solved. This method was verified by simulation and real data of a SRUAV SAR.

关 键 词：合成孔径雷达 二维运动误差 自聚焦 拟极坐标系快速因子分解反向投影 运动补偿 

分 类 号：TN958[电子电信—信号与信息处理]