基于特征值分解和自适应滤波的极化相位优化方法  

A new polarimetric phase optimization method based on eigenvalue decomposition and adaptive filtering

作　　者：姜修成 张正加 王猛猛 刘修国[1] 陈启浩[1] JIANG Xiucheng;ZHANG Zhengjia;WANG Mengmeng;LIU Xiuguo;CHEN Qihao(School of Geography and Information Engineering,China University of Geosciences,Wuhan 430078,China)

机构地区：[1]中国地质大学(武汉)地理与信息工程学院,武汉430078

出　　处：《遥感学报》2024年第3期781-792,共12页NATIONAL REMOTE SENSING BULLETIN

基　　金：国家自然科学基金青年基金(编号:41801348)。

摘　　要：基于分布式散射体DSs (Distributed Scatterers)的时序InSAR技术很好的弥补了PSInSAR技术在低相干区域难以获取足够形变监测点的缺陷。考虑到DS目标容易受时间和空间失相干因素的影响,从而引入斑点噪声,因此优化相干点目标的相位非常必要。基于此,本文提出了一种新的基于特征值分解和自适应滤波的极化相位优化方法 (EVD-FPO)。该方法利用Sentinel-1A双极化数据幅度信息识别DS与PS目标,并基于时空间相干矩阵利用特征值分解极化相位优化技术和自适应均值滤波技术改善相位质量。为了证明本文方法的可行性与有效性,17景Sentinel-1A双极化(VV-VH) SAR数据用于评估本文方法的性能。结果表明:EVD-FPO方法能够有效提高相干目标点的密度和改善相位质量,相较于单极化振幅离差法(VV-D_(A))和振幅离差极化相位优化方法(ESM-D_(A))相干点目标分别增加了9.06倍和1.64倍,相较于单极化CAESAR方法提取的PS目标更加完整。为了定量评价优化后的相位结果,本文采用相位导数变化指标来评估各相位优化方法的相位质量,研究发现ESM-D_(A)方法的平均相位导数为1.184,CAESAR方法的平均相位导数为0.854,EVD-FPO方法的平均相位导数为0.810,表明EVD-FPO方法得到的干涉相位质量高于CAESAR方法和ESM-D_(A)方法。The time-series interferometric synthetic aperture radar(InSAR)technology based on distributed scatterers(DSs)makes up for the drawback of the persistent scatterer InSAR technology,which struggles to obtain a sufficient number of deformation monitoring points in low-coherence regions.Given that DS targets are easily affected by temporal and spatial decorrelation factors,leading to the introduction of speckle noise,the phase of DS targets must be optimized.In this paper,a new polarimetric phase optimization method based on eigenvalue decomposition and adaptive filtering(EVD-FPO)is proposed to address these limitations.This method uses Sentinel-1A dualpolarization data amplitude information to identify DS and PS targets and uses eigenvalue decomposition polarimetric phase optimization technology based on the temporal and spatial coherence matrix and adaptive mean filtering technology to improve the phase quality.To prove the feasibility and effectiveness of the proposed method,17 Sentinel-1A dual-polarization(VV-VH)SAR images are used to evaluate its performance.Experimental results show that the proposed EVD-FPO method can effectively increase the density of coherent target points and improve the phase quality.Compared with the single polarimetric amplitude dispersion method(VV-D_(A))and amplitude dispersion polarimetric phase optimization method(ESM-D_(A)),EVD-FPO increases the coherence point target by 9.06 and 1.64 times,respectively.Compared with the single-polarization CAESAR method,the PSs extracted are more complete.EVD-FPO can suppress the phase noise of the DSs while protecting the phase of the PSs,and the phase quality is better than those of the ESM-D_(A) and CAESAR methods.To evaluate the optimized phase results,this paper adopts the average phase derivative to evaluate the phase quality of each phase optimization method.As for the global average phase derivative,the variation of phase derivative of the ESM-D_(A) method is 1.22,that of the CAESAR method is 0.998,and that of the EVD-FPO method is 0.974.

关 键 词：遥感 极化相位优化 特征值分解 自适应滤波 相干点 INSAR 

分 类 号：P237[天文地球—摄影测量与遥感] P2[天文地球—测绘科学与技术]