An Analysis of Improved Ross-Li Models on the Ability of Estimationg Albedo under Large Solar Zenith Angle by Polder Datasets

Surface albedo is a key parameter controlling the earth energy budget, which can be estimated by integrating the Bidirectional Reflectance Distribution Function (BRDF). The semi-empirical kernel-driven BRDF models has been widely used in BRDF/Albedo products, MODIS products for instance (Schaaf et al., 2002). However, these albedo products are suspect under large SZA (Liu et al., 2009). With the hotspot improved kernel-driven models, it is necessary to assess the property of these models. In this study, two POLDER datasets are utilized to access these models by root-mean-square error (RMSE) and relative RMSE (RMSE r). Then, cross-comparison between albedos estimated by improved models under several SZAs is analyzed by POLDER and the concurrence MODIS pixels. This study is aimed at choosing suitable models for albedo estimation under different angular situations to retrieve more accurate albedo.