对NOAA／AVHRR通道反照率和植被指数的大气影响订正试验

在利用大气窗区进行遥感时，大气成分对辐射的吸收和散射作用造成辐射消弱，从而影响气象卫星（ＡＶＨＲＲ）两个通道（可见光和近红外）反演地表反照率值及其差和比的植被指数值。在选取实测卫星资料对其作预处理并考虑仪器定标衰减作用后，利用ＬＯＷＴＲＡＮ－７大气辐射传输模式对卫星资料进行大气订正的探讨，指出气溶胶、水汽等大气参数是订正计算中的敏感因子。

The Correction Experiment of Atmospheric Effects on NOAA/ AVHRR Channel Albedos and Vegetation Indexes

Meteorological satellites have been used widely in remote sensing of natural resources and environment. The vegetation index calculated by satellite radiative measurements is an important parameter reflecting land surface characteristics, and has already been used in vegetation monitoring, land surface classification and yield estimation and so on. In this paper, the calculation of vegetation index using AVHRR/NOAA-11 the near-IR and visible channel data in 1992 is described, and the necessity to consider the decay of sensitivity of radiometer on satellite in calibration is pointed out. On the other hand, the channel albedos and vegetation indexes have been investigated and a correction experiment of atmospheric effects has been carried out. The results indicate that the vegetation index could describe land surface characteristics well, but the atmosphere has significant impact on it, and it is necessary to make atmospheric correction.