行播冬小麦热辐射方向性的影响因子  

The Affecting Factors of Thermal Radiant Directionality of the Row Winter Wheat

作　　者：范闻捷[1] 徐希孺[1] 

机构地区：[1]北京大学遥感与地理信息系统研究所,北京100871

出　　处：《地理与地理信息科学》2003年第4期84-88,共5页Geography and Geo-Information Science

基　　金：国家自然科学基金资助项目(40171073);科技部国家重点基础研究发展规划项目(G2000077900);国家高技术发展计划(2001AA135110)

摘　　要：混合像元的热辐射方向性由于受到多种因素的影响而变得极为复杂。该文以行播冬小麦为例,建立矩阵模型,研究混合像元热辐射方向性问题。结果表明,混合像元热辐射方向性主要受到混合像元内部各组分在三维上分布的不均一、像元比辐射率的方向性以及由外界影响造成的各组分温度差异的影响。在这三个主要影响因子中,各组分的比辐射率是地物固有的特征,不随外界条件而发生变化。在同温条件下,像元热辐射方向性完全由像元比辐射率的方向性决定。而各组分温度虽然没有方向性,但可以通过组分空间分布对其产生调制作用。The thermal radiant directionality of mixed pixel is very complicated under the influence of many factors. Only through the understanding of the weight of each factor, the problem of radiant directionality of mixed pixel can really be solved. In this paper,the authors establish the matrix model and study the thermal radiation directionality of mixed pixel through a case study of row winter wheat. It shows that the thermal radiation directionality of mixed pixel is decisively influenced by three factors, the heterogeneity and three-dimensional structure of components in mixed pixel, the radiant directionality of emissivity of pixel, and the different temperature of components caused by environment. Among these major factors, the emissivity of pixels is the inherence characteristic of the object surface. It does not change with environmental condition. Radiant directionality of mixed pixel is completely decided by the directionality of emissivity in isothermal condition. Although the temperature of each component has no directionality, it can modulate the directionality of mixed pixel by components distribution in non-isothermal condition. 

关 键 词：行播冬小麦 热辐射方向性 影响因子 混合像元 矩阵模型 比辐射率 热红外遥感 

分 类 号：S127[农业科学—农业基础科学] S512.11