基于子孔径相位误差拼接的相位梯度自聚焦算法  

A Phase Gradient Autofocus Algorithm Based on Subaperture Phase Error Stitching

作　　者：王文 王伟[1] 张俊 WANG Wen;WANG Wei;ZHANG Jun(Xi'an Electronic Engineering Research Institute, Xi'an 710100)

机构地区：[1]西安电子工程研究所,西安710100

出　　处：《火控雷达技术》2021年第1期26-31,共6页Fire Control Radar Technology

摘　　要：随着雷达技术的发展,合成孔径雷达的成像精度也得到了大幅提升,与之相匹配的,也需要能更精确地进行运动补偿的算法。由于惯导精度无法满足需求,如果仅使用惯导数据对运动误差进行补偿,补偿的结果中含有残余的距离单元徙动,这会损失图像的精度。本文首先分析了残余的距离单元徙动对快速分解后向投影成像算法和相位梯度自聚焦算法的影响,再将用于聚束SAR相位误差补偿的相位梯度自聚焦算法进行优化,提出了基于子孔径相位误差拼接的相位梯度自聚焦算法,使其可以对残余的距离单元徙动进行补偿,并可以将其应用到条带SAR的运动补偿中,最后利用Ku波段雷达的实测数据验证算法的有效性。With the development of radar technology,the imaging accuracy of synthetic aperture radar(SAR)has been greatly improved,which requires algorithms that can perform motion compensation more accurately.Accuracy of inertial navigation data is not enough for current SAR imaging.If motion compensation is performed by using only inertial navigation data,the imaging accuracy will be degraded because of residual range cell migration.In this paper,the impact of residual range cell migration on fast factorized back-projection(FFBP)imaging algorithm and phase gradient autofocus(PGA)algorithm is analyzed at first.And then the PGA algorithm for spotlight SAR phase error compensation is optimized,resulting in a PGA algorithm based on subaperture phase error stitching.The proposed PGA algorithm makes it possible to compensate for residual range cell migration,which can also be applied to the strip SAR.At last,the measured data of a Ku-band radar prove the effectiveness of the proposed algorithm.

关 键 词：子孔径相位误差拼接 相位梯度自聚焦算法 运动补偿 快速分解后向投影算法 

分 类 号：TN958.94[电子电信—信号与信息处理]