基于压缩感知的频率分集阵列SAR三维成像方法  

Frequency diverse array 3D-SAR imaging method based on compressed sensing

作　　者：崔昆仑 欧阳缮[1,2] 廖可非 李晶晶[1] CUI Kunlun;OUYANG Shan;LIAO Kefei;LI Jingjing(School of Information and Communication,Guilin University of Electronic Technology,Guilin 541004,China;State and Local Joint Engineering Research Center for Satellite Navigation and Location Service,Guilin University of Electronic Technology,Guilin 541004,China)

机构地区：[1]桂林电子科技大学信息与通信学院,广西桂林541004 [2]桂林电子科技大学、卫星导航定位与位置服务国家地方联合工程研究中心,广西桂林541004

出　　处：《桂林电子科技大学学报》2023年第2期106-113,共8页Journal of Guilin University of Electronic Technology

基　　金：国家自然科学基金(61631019,61701128,61871425);广西创新驱动发展专项(桂科AA21077008);桂林电子科技大学研究生教育创新计划(2020YCX035)。

摘　　要：基于宽带发射信号的相控阵三维合成孔径雷达(SAR)系统硬件设计复杂且接收信号不易分离。通过将频率分集阵列应用到三维SAR中,线阵各阵元只需发射单频信号便可获得宽带观测性能,可大大降低系统硬件要求,但由于频率分集阵列的回波信号具有空间-频率稀疏特性,采用基于匹配滤波思想的传统后向投影算法成像时,分辨率受限且图像旁瓣较高。针对此问题,提出一种基于压缩感知的随机频率分集阵列SAR三维成像方法。该方法通过在切航迹向随机稀疏选取阵元,在沿航迹向随机稀疏选取观测位置,实现对回波数据的二维稀疏采样。在成像部分,采用正交匹配追踪算法对空间目标散射系数进行重构。仿真和实测实验结果表明,该压缩感知成像方法不仅可以减少频率分集阵列三维SAR系统的数据处理量,还能够有效抑制雷达图像旁瓣,成像质量显著提高。利用压缩感知算法,频率分集阵列三维SAR可以在回波稀疏的情况下准确重构目标信息,验证了所提方法的合理性和有效性。The hardware design of phased array three-dimension synthetic aperture radar(SAR)system based on wideband transmission signals is complicated,and the received signals are difficult to separate.By applying the frequency diverse array(FDA)to 3D-SAR,each array element only needs to transmit a single frequency signal to obtain wideband observation performance,which greatly reduces the hardware requirements of system.However,due to the space-frequency sparseness of FDA echo signals,the resolution is limited and the sidelobes of radar images are relatively high when using the back projection(BP)algorithm based on matched filtering.To solve this problem,this paper proposes a random frequency diverse array 3D-SAR imaging method based on compressed sensing(CS).The array elements in the tangent-track and the observation positions in the along-track are selected randomly and sparsely to realize two-dimensional sparse sampling of echo data.In the imaging part,orthogonal matching pursuit(OMP)algorithm is used to reconstruct the scattering coefficient of targets.Simulation and experimental results show that CS method not only reduces the data processing amount of FDA-3D-SAR system during imaging,but also effectively suppresses the sidelobes of radar images,and the imaging quality is significantly improved.By using the compressed sensing algorithm,FDA-3D-SAR can accurately reconstruct the information of space targets when the echo is sparse,which verifies the rationality and effectiveness of the proposed method.

关 键 词：频率分集阵列 合成孔径雷达 压缩感知 三维成像 正交匹配追踪 

分 类 号：TN95[电子电信—信号与信息处理]