罗布泊“大耳朵”成因的体散射特性模拟与分析  

Analyzing the genesis of Lop Nur "Ear" feature based on volume scattering characteristic simulation

作　　者：高志宏[1,2] 邵芸[1] 宫华泽[1] 卞小林[1] 谢酬[1] 蔡爱民[1,2] 万紫[1,2] 王国军[1,2] 

机构地区：[1]中国科学院遥感应用研究所遥感科学国家重点实验室,北京100101 [2]中国科学院研究生院,北京100049

出　　处：《地球物理学报》2012年第3期906-913,共8页Chinese Journal of Geophysics

基　　金：中国科学院知识创新工程重要方向项目(KZCX2-EW-320);中国科学院遥感应用研究所青年人才领域前沿项目(Y1S01200CX);国家高技术研究发展计划项目(2007AA12Z168);遥感科学国家重点实验室开放基金(OFSLRSS201106);遥感科学国家重点实验室自由探索项目资助

摘　　要：根据SAR信号对干燥地表的穿透性能,在对罗布泊湖盆区域复杂散射机制深入分析的基础上,结合野外考察和实验室测量的数据,利用双层散射结构模型对湖盆区域的微波散射特性进行描述,并对次地表稳定沉积物的体散射分量进行模拟.为了对模型进行验证,本文利用Cloude极化分解方法将ALOS PALSAR数据进行散射机制的分解,并以体散射贡献量作为标准数据,与模型模拟的结果进行对比,得到的水平和垂直极化方式的均方根误差分别为1.62%和1.68%,证明了模型的可用性和有效性.同时,对模型的相关参数进行扩展分析,结果表明,次地表稳定沉积物是罗布泊古湖盆演化结果的直接反映,沉积物的含盐量是罗布泊"大耳朵"特征形成的根本原因.Lop Nur is a famous dried up lake in Xinjiang Province of northwest China and finally lost its last drop of water in 1960 s.It is well known for its ＂Ear＂ feature in optical remote sensing images.Likewise,the ＂Ear＂ feature is shown in Synthetic Aperture Radar（SAR） images,and even larger because of penetration effect for SAR signals.That is to say,SAR is capable of detecting subsurface targets and materials.The objective of this paper is to analyze the volume scattering mechanism of subsurface and reveal the genesis of Lop Nur ＂Ear＂ feature with full polarimetic SAR images.Two field investigations were conducted in 2006 and 2008 in order to validate the image interpretation and calculation results.In this study,the scattering physical mechanisms are discussed based on the results of field investigation.A suitable volume scattering model is used to simulate the contribution of volume backscattering to a certain extent.Meanwhile,ALOS PALSAR images for Lop Nur were collected,and the SAR Cloude decomposition method was used to extract the volume scattering components,based on which the developed volume scattering model was validated.The root mean square error（RMSE） of horizontal and vertical polarization are 1.62% and 1.68% representatively,and the fitting effect is relatively good.According to the parameters analysis of the model,it is found that salinity at subsurface is the genesis of ＂Ear＂ feature,which is strongly correlated with Lop Nur evolution.

关 键 词：罗布泊 SAR 极化分解 模型 体散射 

分 类 号：P237[天文地球—摄影测量与遥感] P631[天文地球—测绘科学与技术]