利用MODIS可见光和1．38μm通道反演卷云反射率

Deriving of the cirrus clouds reflectivity utilizing MODIS channels of visible light and 1.38 μm

本文介绍了一种算法,利用TERRA或AQUA卫星平台上的中分辨率成像光谱仪(MODIS)的0.66μm和1.38μm通道来反演卷云双向反射率。资料表明,用1.38μm通道测量的卷云反射率会被卷云上的水汽吸收所削弱。该算法将1.38μm通道所得的反射率与0.66μm通道所得的反射率作比较来衡量这种削弱作用的影响,从而获得可见光谱区域较精确的卷云反射率。

In this paper, we describe an algorithm to retrieve cirrus bidirectional reflectance using channels near 0. 66 and 1.38 μm of the Moderate Resolution Imaging Speetro-Radiometer （MODIS） on the TERRA or AQUA Spacecraft. It is shown that the apparent reflectance of the 1.38 μm channel is essentially the bidirectional reflectance of cirrus clouds attenuated by the absorption of water vapor above cirrus clouds. This algorithm, based on the scatter diagram of 1.38 μm channel apparent reflectance versus 0. 66μm channel apparent reflectance, has been developed to estimate the effect of water vapor absorption, so that the true cirrus reflectance in the visible spectral region can be obtained.