面向双站SAR系统的长波PolInSAR目标自适应分解  

Adaptive Decomposition of Long-Wave PolInSAR Targets for The Bistatic SAR System

作　　者：符龙崇 朱建军[1] 付海强[1] 解清华 韩文涛 FU Longchong;ZHU Jianjun;FU Haiqiang;XIE Qinghua;HAN Wentao(School of Geociences and Info-Physics,Central South University,Changsha 410083,China;School of Geography and Information Engineering,China University of Geosciences(Wuhan),Wuhan 430074,China)

机构地区：[1]中南大学地球科学与信息物理学院,湖南长沙410083 [2]中国地质大学(武汉)地理与信息工程学院,湖北武汉430074

出　　处：《遥感技术与应用》2023年第5期1017-1027,共11页Remote Sensing Technology and Application

基　　金：国家自然科学基金项目“低矮植被覆盖下的双站极化干涉SAR高精度地形测绘研究”(41820104005);国家自然科学基金项目“顾及森林随机体非随机朝向/非均匀分布的长波PolInSAR林下地形反演”(41904004);国家自然科学基金项目“基于长波SAR数据的植被覆盖区时序极化InSAR地表形变监测理论与方法”(42030112);国家自然科学基金项目“顾及植被形态结构异质性的极化干涉SAR林下地形反演研究”(41804004)。

摘　　要：双站SAR系统无时间去相干的特性,结合长波的强穿透能力,在估计植被结构参数上应用前景极大,借助极化干涉SAR分解技术研究双站SAR系统下的植被区散射过程,对揭示信号与地物的交互过程,构建植被结构参数反演模型具有重要意义。考虑模型适用性和双站SAR系统存在的不可忽略的去相干,将极化干涉矩阵表达为极化方位角扩展的广义表面散射矩阵、广义二次散射矩阵和Neumann自适应体散射矩阵与其对应相干成分乘积的和的形式,基于残差最小二乘准则,使用非线性最小二乘优化技术同时求解所有模型参数。使用BioSAR 2008项目的 L波段全极化机载数据对方法进行测试,获取了实验区不同散射机制的相干成分、相位分布和能量信息,结合机载激光雷达数据进行了分析。结果表明:分解方法对植被区不同散射机制区分良好,有效抑制了体散射功率高估;植被区表面散射在垂直向上的分布与植被高度和穿透程度存在联系,体散射相位中心高度与机载激光雷达植被高接近且趋势一致;有效估计了散射机制的相干性。The Bistatic SAR system has no temporal decoherence,and combined with the powerful penetration capability of long wave,it has great prospects for application in estimating vegetation structure parameters.Using polarimetric interferometric SAR decomposition technique to study the scattering process of vegetation area in bistatic SAR system is of great significance for revealing the interaction between signal and ground object and constructing the inversion model of vegetation structure parameters.Considering the applicability of the model and the non-negligible decoherence in bistatic SAR system,the polarization interference matrix is expressed as the sum of the product of the polarization azimuth-extended generalized surface scattering matrix,the generalized quadratic scattering matrix and the Neumann adaptive volume scattering matrix with their corresponding coherent components.Solving all model parameters simultaneously using nonlinear least squares optimization technique based on residual least squares criterion.The method is tested using L-band fully polarimetric airborne data from the BioSAR 2008 project.The coherent components,phase distribution and energy information of different scattering mechanisms in the experimental area are obtained and analyzed with airborne lidar data.The results show that the decomposition method can well distinguish different scattering mechanisms in vegetation area,effectively suppress the overestimation of volume scattering power,and better fit with the actual data.The vertical distribution of surface scattering in the vegetation area is related to the vegetation height and penetration degree.The height of the volume scattering phase center is close to and the trend is consistent with the vegetation height of the airborne lidar.The coherence of the scattering mechanism is effectively estimated.

关 键 词：双站SAR极化干涉测量 长波 目标自适应分解 植被区散射机制 

分 类 号：TN911.7[电子电信—通信与信息系统]