Deriving albedo over cloudy areas with composite inversion

摘要

A new way called compositive inversion is presented in the paper to derive albedo over cloudy areas with multi-angular satellite remote sensing data. It combines complementary angular clear observations of pixels having same BRDF shape and directly retrieves BRDF parameters and albedo with RossThick-LiSparse Reciprocal model when the minimum multi-angular observations meet its requirement. Contrastive retrieval experiments with five continuous 16-day Terra MODIS data over the Tibetan Plateau (30 cases in total) showed that its retrieval capability is much higher than that of the magnitude inversion, a backup algorithm adopted by the U.S. BRDF/albedo products, and accuracy of its retrievals is rather equivalent to those with magnitude inversion. Since the unique ancillary data used in which is the land-cover type classification data, which is superior over a priori BRDF database, so the compositive inversion can give more accurate albedo information, and is an applicable and practical way to derive albedo of cloudy areas. The idea of compositive inversion provides a new way to derive albedo in shorter temporal cycle and a particular view for use of multi-angular remote sensing data to derive land surface information.