青藏高原MODIS地表反照率和GLASS地表反照率的对比分析

对比分析了青藏高原MODIS地表反照率产品和GLASS地表反照率产品的空间分布连续性、高质量反演结果的比例，应用青藏高原CAMP/Tibet试验期间的高精度观测数据评估了两种产品的精度，通过人工目视解译MODIS地表反射率图像并结合MODIS积雪产品分析了影响两种产品精度的原因，结果表明：1）GLASS地表反照率产品具有比MODIS地表反照率产品更好的空间分布连续性和更高的反演质量；2）绝大多数时段内两种产品都能与地面观测结果保持较好的一致性，能准确地反映地表反照率的异常变化过程；3）局地积雪是影响两种产品精度的重要因素之一；4）积雪条件下，GLASS地表反照率反演算法比MODIS地表反照率反演算法更具优势。研究结果有助于促进人们对地表反照率卫星遥感反演产品的认识，改进青藏高原地表反照率卫星遥感反演算法，提高青藏高原地表反照率卫星遥感反演结果的精度、反演质量和空间分布连续性。

Comparative analysis on land surface albedo from MODIS and GLASS over the Tibetan Plateau

In this paper,the spatial distribution continuity and ratio of the high-quality retrievals over the Tibetan Plateau of two land surface albedo products,namely MODIS(MODerate resolution Imaging Spectroradiometer)land surface albedo and GLASS (Global LAnd Surface Satellite Products System)land surface albedo,were comparatively analyzed.Next,the accuracies of these two products were evaluated using the high-precision ground observation data obtained during the CAMP/Tibet experiments.Furthermore,the factors affecting the accuracies of these two products were analyzed through artificial visual interpretation combined with the MODIS snow product.The results of the study are as follows:1)The product of the GLASS land surface albedo is superior to that of the MODIS land surface albedo in terms of both spatial distribution continuity and the ratio of the high-quality retrievals.2)These two products both have high consistency with land surface albedo ground measurements during most of the retrieval periods,and rather accurately reflect the abnormal changing processes of land surface albedo.3)The patchy snow is an important factor affecting the accuracies of these two products when performing comparison with the ground measurements.4)The inversion algorithm of the GLASS land surface albedo has a great advantage over that of the MODIS land surface albedo under snow conditions.The above results are conducive to the users to acquiring better knowledge of these two products.In addition,the results also contribute to the improvements of the algorithm of satellite remote sensing land surface albedo over the Tibetan Plateau,so as to assist in obtaining retrievals with better precision,quality and spatial distribution continuity.