圆周扫描地基合成孔径雷达极坐标格式成像算法  

Polar Format Algorithm for Circular SAR Imaging

作　　者：张远 贾林靖 王彦平 李伟[1] ZHANG Yuan;JIA Linjing;WANG Yanping;LI Wei(Information Science and Technology,North China University of Technology,Beijing 100144,China)

机构地区：[1]北方工业大学信息学院,北京100144

出　　处：《信号处理》2023年第5期858-865,共8页Journal of Signal Processing

基　　金：北京市自然科学基金(4202019)。

摘　　要：圆周扫描地基合成孔径雷达(圆周扫描地基SAR)成像是一种实现360度全方位观测的合成孔径雷达成像技术。现有的成像算法存在计算效率随场景扩大而降低和斜距近似导致的成像精度下降问题,难以实现实时成像。本文提出一种新的圆周扫描地基SAR成像的算法。该算法的基本思想是:首先,将球面波回波信号进行分解,表示为平面波积分形式;其次,构造扫描角度方向的滤波器,利用傅里叶变换的卷积定理,消除角度方向的高阶相位误差;进一步对信号进行极坐标转直角坐标插值,实现角度方向与距离方向的解耦;最终,通过二维逆傅里叶变换实现目标聚焦。通过仿真和实际数据实验对算法进行验证,并对本文算法与BP算法在成像质量和成像效率方面进行对比,证明本文算法可以实现高效成像。Circular Synthetic Aperture Radar(Circular SAR)imaging is a synthetic aperture radar imaging technology that realizes 360 degree omnidirectional observation.The existing Circular SAR imaging algorithms have the problems of low computational efficiency as the scene expands and reduced imaging accuracy caused by the slant-range approximation,difficult to achieve real-time imaging.In this paper,a new algorithm for Circular SAR imaging is proposed.First,the echo signal in the form of spherical wave is decomposed into an integral of plane waves.Second,according to the integration,an angular filter can be constructed by virtue of the convolution theorem,which is used to eliminate the high-order phase error in the scanning angle direction.Next,the interpolation from the polar to rectangular coordinates on the filtered signal is performed to achieve decoupling of the scanning angle and wavenumber.Finally,the target focusing is achieved by 2-D inverse Fourier transform.The algorithm is verified by simulation and actual data experiments,and the comparison between the algorithm in this paper and the BP algorithm in terms of imaging quality and imaging efficiency proves that the algorithm in this paper can achieve high-efficiency imaging.

关 键 词：合成孔径雷达(Synthetic aperture radar SAR) 圆周扫描地基合成孔径雷达(圆周扫描地基SAR) SAR成像 

分 类 号：TN958[电子电信—信号与信息处理]