距离-多普勒-频带域3D-AWP-MRF分类辅助的SARGMTI杂波抑制方法  

A Multichannel SAR-GMTI Clutter Suppression Method Assisted by Range-Doppler-Band 3D-AWP-MRF Classification

作　　者：韩超垒 杨志伟[1] 张庆君[2] 廖桂生[1] 何鹏远 HAN Chao-lei;YANG Zhi-wei;ZHANG Qing-jun;LIAO Gui-sheng;HE Peng-yuan(National Laboratory of Radar Signal Processing,Xidian University,Xi’an,Shaanxi 710071,China;China Academy of Space Technology,Beijing 100094,China)

机构地区：[1]西安电子科技大学雷达信号处理国家重点实验室,陕西西安710071 [2]中国空间技术研究院,北京100094

出　　处：《电子学报》2021年第12期2339-2348,共10页Acta Electronica Sinica

基　　金：国家自然科学基金(No.62071481);国家青年基金(No.61801373);上海航天科技创新基金资助项目(No.SAST2018043;No.SAST2019036)。

摘　　要：针对复杂地理场景下非均匀杂波造成多通道SAR-GMTI(Synthetic Aperture Radar Ground Moving Target Indicator,合成孔径雷达动目标指示)系统杂波抑制性能下降的问题,本文提出一种距离-多普勒-频带域三维自适应加权惩罚马尔科夫场(Three Dimension Adaptive Weighted Penalty Markov Random Field,3D-AWP-MRF)分类辅助的SARGMTI杂波抑制方法.利用地物类型在距离-多普勒-频带三维SAR图像空间的马尔科夫性,构造了包含空间距离、类间Fisher距离、局部粗糙度距离和梯度方向距离的自适应加权惩罚函数.在贝叶斯框架下利用条件迭代模型(Iterated Conditional Mode,ICM)算法求解距离-多普勒单元所属地物类型的最大化后验概率对多频带SAR图像进行分类,接着利用图像形态学操作对图像分类结果进行区域提取.最后,对每个闭合区域分别估计杂波协方差矩阵,并进行自适应杂波抑制处理.相比于传统方法,本文方法在非均匀杂波环境下不仅能提高起伏区域强杂波10~15dB的强杂波抑制能力,还可以减少平坦区域慢速运动目标约2.5dB的输出能量损失.To address the problem that the clutter suppression performance of a multichannel synthetic aperture ra⁃dar ground moving target indicator(SAR-GMTI)system is reduced due to non-uniform clutter in a complex geographical scene,we propose a multichannel SAR-GMTI clutter suppression method assisted by Range-Doppler-Band three dimen⁃sion adaptive weighted penalty markov random field(3D-AWP-MRF)classification.Firstly,an adaptive weighted penalty function is constructed using the markov properties of the feature types in the Range-Doppler-Band 3D SAR image do⁃main.Spatial distance,inter-class Fisher distance,local roughness distance,and gradient direction distance are included.Subsequently,in the Bayesian framework,iterated conditional mode(ICM)algorithm is used to solve the maximum poste⁃rior probability of the feature type of the Range-Doppler unit,so as to accurately classify the multiband SAR images.Then,the image classification results are obtained by image morphology operation.Finally,the clutter covariance matrix is estimated separately for each closed region,and adaptive clutter suppression processing is performed.Compared with the traditional method,the proposed method not only can improve the suppression performance about 10~15 dB for the strong clutter in undulating areas,but also reduce the output signal power loss about 2.5dB of the moving targets in flat areas.

关 键 词：SAR-GMTI 杂波抑制 多频带 马尔科夫 杂波分类 自适应惩罚加权 

分 类 号：TN958.[电子电信—信号与信息处理]