| 植被层对被动微波遥感土壤水分反演影响的研究 |
| |
| 引用本文： | 张钟军,孙国清,朱启疆.植被层对被动微波遥感土壤水分反演影响的研究[J].遥感学报,2004,8(3):207-213. |
| |
| 作者姓名： | 张钟军 孙国清 朱启疆 |
| |
| 作者单位： | 1. 北京师范大学,遥感与GIS研究中心,北京,100875
2. 美国马里兰大学地理系,MD 20742,美国 |
| |
| 基金项目： | 国家 973项目“地球表面时空多变要素的定量遥感理论与应用”(G2 0 0 0 0 7790 8)，北京师范大学信息科学学院“微波辐射模型和应用研究”的资助 |
| |
| 摘 要： | 在很多对土壤水分被动微波遥感的研究中 ,为简单起见 ,覆盖的植被层使用了一种简单的模型来表征其散射和衰减特性。本文中使用了一种基于辐射传输理论的离散模型来研究植被的发射率、传输率。这种方法可以更加真实地刻划组成植被的散射个体如叶、茎、树枝、树干等对这两个参数的影响 ,因而能更准确地描述植被对下垫面的影响。为了减少土壤水分反演算法中未知量的数目 ,该文给出了这两个参数的模拟结果分别在AMSR E三种不同频率下的简单关系。
|
| 关 键 词： | AMSR-E 发射率 传输率 单散射反照率 Stokes矩阵 |
| 文章编号： | 1007-4619(2004)03-0207-07 |
| 收稿时间： | 2002/10/8 0:00:00 |
| 修稿时间： | 2002年10月8日 |
The Study of Vegetation Effect on Passive Microwave Soil Moisture Retrieval |
| |
| ZHANG Zhong-jun,SUN Guo-qing and ZHU Qi-jiang.The Study of Vegetation Effect on Passive Microwave Soil Moisture Retrieval[J].Journal of Remote Sensing,2004,8(3):207-213. |
| |
| Authors: | ZHANG Zhong-jun SUN Guo-qing and ZHU Qi-jiang |
| |
| Institution: | Research Center for Remote Sensing and GIS,Beijing Normal University,Beijing 100875,China;Department of Geography,University of Maryland,MD 20742,USA;Research Center for Remote Sensing and GIS,Beijing Normal University,Beijing 100875,China |
| |
| Abstract: | 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. |
| |
| Keywords: | AMSR-E emissivity stokes matrix single scattering albedo |
| 本文献已被 CNKI 维普 万方数据 等数据库收录！ |
| 点击此处可从《遥感学报》浏览原始摘要信息 |
| 点击此处可从《遥感学报》下载免费的PDF全文 |
|
