辐照度基法确定卫星各波段的定标系数时,要求精确测量辐射定标场的地表反射率和漫射辐射度与总辐射度的比值。中国科学院通用光学定标与表征技术重点 实验室分别于2013年6～8月及2014年8月期间,协同其他单位在敦煌校正场运用辐照度基法进行场地辐射定标,实测过程中使用ASD、SVC光谱辐射计,运用野 外参考板反射率因子法确定敦煌校正场的地表反射率。详细阐述地表反射率测量方式及数据处理方法,根据实地观测数据,分析当前场区的地表反 射率并与历史数据相互比对。结果显示,敦煌校正场地表反射率在时间和空间上均保持良好的稳定性。

Precise measurement of radiation calibration field surface reflectivity and the ratio between diffuse and total radiation are required when using the irradiance-based method to determine the satellite calibration coefficient of each band. From June to August in 2013, Anhui Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, allying with other units, calibrated X satellite by using the irradiance-based method in Dunhuang Radiometric Calibration Test Site. ASD, SVC spectral radiometer were used and the surface reflectance was obtained by reference board reflectivity modify method during the measure process. The surface reflectance measurement and data processing method were elaborated, and the reflectance characteristics between 2013 and historical data were contrasted and analyzed. The results indicated that the surface reflectance of Dunhuang Radiometric Calibration Test Site maintained good stability both in space and time.