基于目标相干性表征差异的多波段SAR相干变化检测方法  

Multi-band SAR Coherent Change Detection Method Based on Coherent Representation Differences of Targets

作　　者：冀广宇 董勇伟[1,2] 卜运成 李焱磊 周良将[1,2] 梁兴东 Ji Guangyu;Dong Yongwei;Bu Yuncheng;Li Yanlei;Zhou Liangjiang;Liang Xingdong(Key Laboratory of Science and Technology on Microwave Imaging,Institute of Electronics Chinese Academy of Sciences,Beijing 100190,China;University of Chinese Academy of Sciences,Beijing 100049,China)

机构地区：[1]中国科学院电子学研究所微波成像技术重点实验室,北京100190 [2]中国科学院大学,北京100049

出　　处：《雷达学报（中英文）》2018年第4期455-464,共10页Journal of Radars

基　　金：国家部委基金~~

摘　　要：相干变化检测(Coherent Change Detection,CCD)利用变化前后SAR图像间的相位相干性检测场景中发生的微小变化。传统的CCD方法由于对目标探测尺度单一,难以区分场景中目标变化区域与低相干干扰区域。多波段SAR对目标进行多尺度探测,依据电磁波对目标的穿透特性、目标的结构特性以及目标发生的变化尺度形成不同的相干性表征。该文据此提出一种多波段CCD方法。该方法先分别获取各个波段的相干变化差异图,然后依据目标的多波段相干性表征使用改进的期望最大化(Expectation-Maximization,EM)算法对场景分类,接下来根据少量监督样本确定目标变化类别,最后用Dempster-Shafer(DS)证据理论处理,获取多波段融合相干变化差异图。该结果可有效排除各个单波段存在的低相干干扰,达到降低虚警概率的目的。该文采用变化前后的L波段与P波段重轨SAR数据进行方法验证,实验结果与指标参数证明了该方法的有效性与正确性。Coherent Change Detection （CCD） detects micro changes in a scene using phase coherence of SAR images before and after a change. It is difficult for conventional CCD method to distinguish low coherence interference region from objective change region because of a single detection scale. Multi-band SAR target detection in a multiscale way develops variable coherent representation according to the diversity of electromagnetic wave penetration, target structure, and change magnitude. In this paper, a multi-band CCD method is proposed. Firstly, the CCD images of every band were acquired; secondly, the detected scene was classified on the basis of coherent representation of targets in each single band using improved Expectation- Maximization （EM） algorithm; thirdly, the objective change class in each single band was selected by a few supervised samples; lastly, multi-band fusion CCD image was acquired by the use of Dempster-Shafer （DS） evidence theory. This multi-band CCD result can eliminate low coherent interference in each single band and decrease false alarm probability. The method is validated by L- and P-band repeat-pass SAR images acquired before and after change. Results and index parameters demonstrate the validity and correctness of the proposed method.

关 键 词：相干变化检测 多波段合成孔径雷达 相干性表征 EM算法 DS证据理论 

分 类 号：TP751.1[自动化与计算机技术—检测技术与自动化装置]