地面热红外发射率的天顶角变化效应

DEPENDENCE OF INFRARED EMISSIVITY ON VIEW ZENITH ANGLE FOR NATURAL GROUND SURFACES

  • 摘要: 文中着重研究了自然地表面的红外辐射的方向特征,实地测量了发射率随观测天顶角的变化,分别对卫星资料反演地面温度和地面辐射测量作出红外发射率的观测天顶角修正,两者比较的结果表明,发射观测天顶角修正在精确地面温度的反演计算中不可忽视,尤其在大角度观测情况下,对某些地物发射率方向特征的修正比发射率本身的修正更重要。

     

    Abstract: The present paper concentrates on investigating the dependence of emissivity on view zenith angle for natural ground surfaces, The in-situ measurements of emissivity have been made with dif ferent view zenith angles for several materials on the ground. The angular correction of infrared emissivity was made for land surfaces' temperature both inversed from satellite data and measured by groundbased radiometer. The comparison of the results inversed by AVHRR data with that measured by ground radiometer shows that the correction of the angular effect of emissivity can not be neglected for land surface temperature derived by remote sensing methods. In the case of very large viewing zenit hangles the angular correction is more important than emissivity correction itself.

     

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