基于物理模型的被动微波遥感反演土壤水分  

Physically based retrieval of soil moisture using passive microwave remote sensing

作　　者：陈亮[1,2] 施建成[1] 蒋玲梅[3] 杜今阳[1] 

机构地区：[1]中国科学院遥感应用研究所,北京100101 [2]中国科学院研究生院,北京100039 [3]北京师范大学地理学与遥感科学学院,北京100875

出　　处：《水科学进展》2009年第5期663-667,共5页Advances in Water Science

基　　金：国家高技术研究发展计划(863)资助项目(2007AA12Z135)~~

摘　　要：利用土壤水分和海洋盐度（sMOs）卫星进行土壤水分反演的算法中，对地表发射率的描述仍采用半经验QIH模型，该模型描述地表粗糙度对有效发射率在V和H极化下影响相同。基于微波散射理论模型一高级积分方程模型（AIEM）建立了一个针对SMOS传感器的参数配置，包含各种地表粗糙度和介电特性的裸露地表辐射模拟数据库，发展了L波段多角度地表辐射参数化模型。在此基础上，利用SMOS多角度双极化特点，建立了土壤水分反演算法。该算法可以消除粗糙度对土壤水分反演的影响，同时最小化反演过程中辅助信息引入带来影响。反演算法通过美国农业部提供的L波段多角度地基辐射计数据（BARC）进行验证，在20°-50°入射角，土壤水分反演精度在4％左右。The soil moisture inversion algorithm, which is adopted in the soil moisture and ocean salinity （SMOS） mission, uses the semi-empirical Q/H model to figure out the surface emissivity. The Q/H model shows the effects of the surface roughness on the emissivity at V polarization are same as that of H polarization. In this study, we use the advanced integral e- quation model to generate a simulated database with a wide range of the surface roughness and soil moisture conditions under SMOS sensor configurations and develop a simplified multi-angular surface emission model based on the simulated database. Based on the parameterized model, an inversion procedure is set up in terms of dual-polarization microwave brightness temper- atures to retrieve soil moisture with the minimum auxiliary information about the ground. The inversion technique is validated with multi-angular ground microwave radiometer experiment data at L-band from several test sites at Beltsville, MD. The accu- racy in random-mean-square error is about 4% at inciden angles of 20°-50°. The results reveal that the proposed inversion procedure decreases the perturbing effects of the surface roughness on the soil moisture estimation.

关 键 词：物理模型 微波遥感 土壤水分 L波段 多角度 

分 类 号：P343.8[天文地球—水文科学]