基于BP和PGA算法的斜视SAR成像方法  

Imaging algorithm for squint SAR based on back projection and phase gradient autofocus method

作　　者：闫梦圆 高安琪 薛晨 孙兵[1] 李景文[1] YAN Mengyuan;GAO Anqi;XUE Chen;SUN Bing;LI Jingwen(School of Electronic and Information Engineering,Beihang University,Beijing 100083,China)

机构地区：[1]北京航空航天大学电子信息工程学院,北京100083

出　　处：《中国传媒大学学报（自然科学版）》2021年第3期25-31,共7页Journal of Communication University of China：Science and Technology

基　　金：国家自然科学基金项目(62071022)。

摘　　要：在斜视合成孔径雷达(Synthetic Aperture Radar,SAR)成像的情况中,由于目标的运动或者平台运动误差,导致成像结果方位向散焦,需要通过相位梯度自聚焦(Phase Gradient Autofocus,PGA)处理改善图像质量。但由于斜视成像时点目标扩展函数二维不正交,采用传统自聚焦算法难以提取出强点目标较完整的方位向能量进行自聚焦处理,聚焦效果不佳。本文提出了一种基于BP(Back Projection)算法成像点目标扩展函数(Point Spread Function,PSF)二维不正交的自聚焦方法,利用后向投影算法对晃动的舰船目标进行成像,通过坐标旋转解决方位向倾斜导致PGA性能不佳的问题,得到聚焦良好的图像。仿真结果验证了本文方法的有效性。In the case of squint SAR imaging,the movement of target and the error of platform movement can generate the echo phase error,resulting in azimuth defocusing.Phase Gradient Autofocus(PGA)processing is need to improve image quality.However,the Point Spread Function is not orthogonal in two dimensions during the squint imaging.Using the traditional autofocus algorithm is hard to extract the complete azimuth energy of the strong point target for autofocus processing,leading to poor focusing.This paper proposes a 2D Non-Orthogonal Point Spread Function(PSF)autofocus algorithms for squint SAR based on BP imaging algorithm.Using BP algorithm to image the shaking ship target.Using coordinate rotation to solve the problem of poor PGA performance caused by azimuth tilt,finally we get a well-focused image.The simulation results verify the effectiveness of this method.

关 键 词：斜视SAR 后向投影算法 相位梯度自聚焦 点目标扩展函数 

分 类 号：TN957.52[电子电信—信号与信息处理]