基于多角度双层偏差度量的封闭空间SAR多径抑制方法  

Closed Space SAR Multipath Suppression Method Based on Multi-angle Dual-layer Deviation Measurement

作　　者：林赟 赵甲萌 王彦平 李洋[1] 申文杰 白泽朝 蒋雯 LIN Yun;ZHAO Jiameng;WANG Yanping;LI Yang;SHEN Wenjie;BAI Zechao;JIANG Wen(Radar Monitoring Technology Laboratory,School of Information,North China University of Technology,Beijing 100144,China)

机构地区：[1]北方工业大学信息学院雷达监测技术实验室,北京100144

出　　处：《雷达学报（中英文）》2024年第4期761-776,共16页Journal of Radars

基　　金：国家自然科学基金(62131001,62371005);北京市教育委员会创新团队建设计划项目(IDHT20190501)。

摘　　要：合成孔径雷达(SAR)具有全天时全天候非接触式监测的优势,是封闭空间安全监测的重要工具。然而,SAR应用于复杂封闭空间时,易受多径效应影响,导致图像存在大量虚像,严重影响判读。现有方法需要场景先验进行多径推算或通过子孔径加权融合抑制多径,但都难以准确区分多径虚像与目标图像。该文提出了一种新的多角度双层偏差度量方法,可有效获取多径虚像与目标间的特征差异。该方法首先采用大视角差对观测场景进行多角度观测,可充分利用多径虚像位置随观测角度变化,而实际目标位置保持不变的特性。然后使用双层偏差度量算法,该算法根据多径在多角度序列中的稀疏性,两次计算序列幅度值与序列均值的偏差,精准检测出稀疏、不稳定的多径成分并去除,对剩余稳定成分取均值。这样,在保留目标信息的同时有效抑制多径。最后,仿真和毫米波雷达实际数据处理验证了该文方法的有效性。Synthetic Aperture Radar(SAR)has the advantage of noncontact monitoring around the clock and is an important tool for closed space security monitoring.However,when SAR is employed in complex closed spaces,it is susceptible to multipath effects,resulting in a considerable number of virtual images in the image,which has a detrimental impact on interpretation.Existing methods require scene priors for multipath estimation or subaperture weighted fusion to suppress multipath;however,accurately distinguishing multipath virtual images from target images is challenging.This paper proposes a novel multi-angle dual-layer deviation measurement method that effectively distinguishes multipath virtual images from targets.The proposed method employs a large viewing angle difference to conduct multi-angle observation of the target scene,capitalizing on the fact that the position of the multipath virtual image varies with the observation angle,whereas the actual target position remains constant;this is followed by applying a dual-layer deviation measurement algorithm.The algorithm calculates the deviation between the sequence amplitude value and mean twice based on the sparsity of multipath in the multiangle sequence.The proposed method accurately detects and removes sparse and unstable multipath components,whereas the remaining stable components are averaged.This effectively suppresses multipath while retaining target information.Finally,the simulation and actual millimeter wave radar data processing verified the effectiveness of the proposed method.

关 键 词：毫米波雷达 多径抑制 多角度观测 双层偏差度量 封闭空间 

分 类 号：TN95[电子电信—信号与信息处理]