青藏高原GLASS地表反照率产品精度分析

An assessment on the accuracy of the GLASS albedo products over the Tibetan Plateau

应用2003年青藏高原3个站点的地表反照率观测结果,对比分析了GLASS(Global LAnd Surface Satellites)地表反照率1 km×1 km分辨率产品的精度,结果表明,GLASS黑空反照率、白空反照率与地表反照率地面观测结果的总体变化趋势基本一致,能够有效地反映实际地表状态的变化;局地积雪和云覆盖对GLASS地表反照率产品的精度影响较大,云覆盖导致GLASS地表反照率可能比实际地表反照率高;消除云覆盖和局地积雪的影响后,GLASS黑空反照率、白空反照率与地表反照率地面观测结果的均方根误差显著降低,分别为0.0155和0.0190。

The accuracies of the GLASS（Global LAnd Surface Satellites）albedo products in1 km resolution are assessed using the ground measurements of year 2003 at three stations over the Tibetan Plateau.The results show that the overall change trends of the GLASS black-sky and white-sky albedos are consistent with the ground-observed albedos,which could indicate the state of surface fair well;both the small fraction of snow cover and cloud cover have great effect on the accuracy of the GLASS albedo products and cloud cover might result in higher values of GLASS albedo products than ground measurements;the RMSEs（root-mean-square errors）between the GLASS black-sky albedos,GLASS white-sky albedos and ground measurements are evidently decreased when eliminating the effect of snow and cloud cover,which are 0.0155 and 0.019,respectively.