积雪和植被被动微波遥感矢量辐射传输的累加-倍加法

项目名称： 积雪和植被被动微波遥感矢量辐射传输的累加-倍加法

项目编号： No.41475018

项目类型： 面上项目

立项/批准年度： 2015

项目学科： 天文学、地球科学

项目作者： 杨文

作者单位： 中国科学院寒区旱区环境与工程研究所

项目金额： 73万元

中文摘要： 积雪和植被被动微波矢量辐射传输方程快速、准确的数值解无论对微波遥感理论建模还是对遥感应用都是非常重要的。利用调整的Debye公式和Polder-Van/de Loor 多相混合公式计算积雪与植被层的平均介电常数；对于离散粒子介质，建立薄层积雪热辐射的零阶近似，漫射反射与漫射透射的一阶近似；重点探讨水平与垂直极化消光系数不相等时，连续随机植被介质的热辐射、反射与透射矩阵的近似形式；由此构建多分层、非均匀离散粒子介质被动微波遥感的累加―倍加辐射传输方法；发展、建立连续随机介质被动微波遥感的完全矩阵形式的累加―倍加法矢量辐射传输模式，初步阐明积雪、植被亮度温度与介质的介电特性、粒子等效半径、含水量和温度等参数的定量关系，进而为遥感数据的分析和应用，参数的反演等提供可靠的理论计算平台，对进一步发展遥感新方法、新手段，也具有一定的科学指导意义。

中文关键词： 矢量辐射传输模式；被动微波遥感；累加-倍加法；积雪；植被指数

英文摘要： The fast and accurate solutions to vector radiative transfer equations of snowpack and vegetation canopy are very important for either radiative transfer theory or remote sensing. The average dielectric constants of snowpack and vegetation are calculated by modified Debye formula and Polder-Van/de Loor mixture one, respectively. For discrete scatterer media of thin layer snowpack, thermal radiative transfer is approximated to zero order, while the diffuse reflection and transmission coefficients to first order, i.e. single scattering approximations for thin media layer. At same time, for continuoue random media of vegetation, it should be focused to the thermal emission, reflection, transmission coefficients matrix when horizontally polarized extinction coefficient is not equal to the vertically polarized one, which just is the case of continuous random media of vegetation. The main purpose is to build the adding-doubling method (ADM) of vector radiative transfer equation for multilayered inhomogeneous random media (e.g. snowpack and vegetation canopy), especially to obtain the ADM in full matrix style. Based on this ADM, the quantitative relationship between brightness temperatures and the physical parameters （dielectric properties,effective radius,water equivalent,temperature）of random media is concisely explained. In this way it can serve as a numerical computation platform, and is very important for remote sensing and new method building in random media.

英文关键词： vector radiative transfer model;passive microwave remote sensing;adding-doubling method;snow;vegetation