%0 Journal Article
%T The Study of Vegetation Effect on Passive Microwave Soil Moisture Retrieval<br>植被层对被动微波遥感土壤水分反演影响的研究
%A ZHANG Zhong jun
%A SUN Guo qing
%A ZHU Qi jiang
%A <br>张钟军
%A 孙国清
%A 朱启疆
%J 遥感学报
%D 2004
%I 
%X The commonly used soil moisture retrieval at vegetated area from microwave radiometry data assume a simple model of vegetation, which is characterized by vegetation volume fraction, effective dielectric constant, plant moisture content, etc. This algorithm is successfully applied under lower frequencies and lower vegetation, but the data used in single scattering albedo is simply assigned a fixed value which is independent of frequencies and polarization, sometimes are even set to zero. In this study, a radiative transfer model is used to model the emissivity and transmissivity of forest canopy, which is more realistically characterized as a volumetric medium consisting of discrete scatters (leaves, stems, tree branches, and trunks.) The scattering coefficient is obtained by integrating the Stokes matrix in the whole sphere region, the extinction coefficient is calculated by forward scattering theory. This mode is expected to cover a wider frequency range as well as vegetation species from lower crop to forest canopy. To facilitate the soil moisture inversion from radiometric data, the unknown variables need to be reduced. The possibility of fitting the modeled emissivity and transmissivity of vegetation canopy into simple equations, and the relationships of these parameters between different microwave radiometric frequencies were studied and the results are presented in this paper.
%K AMSR-E
%K emissivity
%K stokes matrix
%K single scattering albedo<br>AMSR-E
%K 发射率
%K 传输率
%K 单散射反照率
%K Stokes矩阵
%U http://www.alljournals.cn/get_abstract_url.aspx?pcid=E62459D214FD64A3C8082E4ED1ABABED5711027BBBDDD35B&cid=A41A70F4AB56AB1B&jid=F926358B31AC94511E4382C083F7683C&aid=7D1F9FACC8B02A6A&yid=D0E58B75BFD8E51C&vid=5D311CA918CA9A03&iid=38B194292C032A66&sid=334E2BB8B9A55ABB&eid=527AEE9F3446633A&journal_id=1007-4619&journal_name=遥感学报&referenced_num=7&reference_num=23