提出了基于自动化多通道光谱辐射计(ATR)、6SV辐射传输模型、敦煌场地历史高光谱反射率模型、中分辨率成像光谱仪(MODIS)的双向反射分布函数(BRDF)的自动化辐射定标方法。当天气状况和卫星观测几何参数满足条件时,所提方法可对遥感器进行连续辐射定标。2015年8月至2016年3月在敦煌辐射校正场进行了实验,共获取17天的有效观测数据。以“水”卫星的中分辨率成像光谱仪(AQUA/MODIS)为辐射基准,验证了所提方法的精度和定标频次。结果表明平均10~15天能够对卫星遥感器进行一次辐射定标。与AQUA/MODIS各通道观测数据相比,利用所提方法得到的大气顶反射率的相对偏差均小于5%,平均相对偏差小于2%,标准差小于2%。

An automated radiation calibration method is proposed based on the automated multichannel spectral radiometer (ATR), 6SV radiometric transfer model, historical hyperspectral reflectance model of Dunhuang site and moderate-resolution imaging spectroradiometer (MODIS) bidirectional reflectance distribution function (BRDF). The proposed method can be used for radiation calibration continuously when the weather and satellite observation geometry parameters satisfy the conditions. Experiments are carried out at Dunhuang radiometric calibration site from August 2015 to March 2016, and effective observation data in 17 days is obtained. AQUA/MODIS is used as radiation benchmark to verify the accuracy and calibration frequency. Results show that the radiometric calibration for a satellite remote sensor can be conducted per average 10-15 days. The reflectivity at top of the atmosphere obtained by the proposed method is compared with the observed data by each channel of AQUA/MODIS, and we find that the relative deviation is less than 5%, the mean relative deviation is less than 2%, and the standard deviation is less than 2%.