%0 Journal Article
%T The Thermal Radiant Directionality of Continuous Vegetation<br>连续植被的热辐射方向性
%A CHEN Liang fu
%A LIU Qin huo
%A <br>陈良富
%A 柳钦火
%J 遥感学报
%D 2001
%I 
%X The correct recognition of radiant directionality of non isothermal mixed pixel is a precondition to its retrieval of component temperatrues. Based on the local thermal equilibrium and component effective emissivity concept the radiant model of continuous vegetation has been studied. The model shows that the radiant directionality of isothermal mixed pixel is fully dependent on that of whole effective emissivity of pixel, which is a function of component emissivities and the crown construct. For nonisothermal mixed pixel, the component temperatures play important role in adjustment of radiant directionality. The paper studies the relationship between the radiant directionality with leaf facet emissivity, soil surface emissivity, leaves area index ( LAI ) and leaves angle distribution ( LAD ) by Monte Carlo simulated results, it further analyses the whole effective emissivity and radiance increments caused by cave effects. Take the spherical type of LAD as an example, and set the values of leaf facet emissivity and soil surface emissivity to 0.98 and 0.94 respectively, the increment of whole effective emissivity ranges from 0.01 to 0.025 when value of LAI is set to more than 1.0 in nadir direction. When the vegetation and soil system is isothermal with 293K temperature, the radiant brightness temperature increment is more than 0.8K, the maximum is 1.3K caused by cave effects.
%K Component effective emissivity
%K thermal radiant directionality
%K cave effects
%K Monte Carlo simulation<br>组分有效发射率
%K 热辐射方向性
%K 孔穴效应
%K 蒙特卡罗模拟
%K 陆面温度
%K 植被叶面
%K 热红外遥感
%K 土壤
%U http://www.alljournals.cn/get_abstract_url.aspx?pcid=E62459D214FD64A3C8082E4ED1ABABED5711027BBBDDD35B&cid=A41A70F4AB56AB1B&jid=F926358B31AC94511E4382C083F7683C&aid=BB92844F0B2DD115&yid=14E7EF987E4155E6&vid=94C357A881DFC066&iid=B31275AF3241DB2D&sid=8CCD0401CC9AE432&eid=BFB86B6ED3A99B9D&journal_id=1007-4619&journal_name=遥感学报&referenced_num=2&reference_num=34