The Bidirectional Reflectance Signature of Typical Land Surfaces and Comparison of MISR and MODIS BRDF Products

The bidirectional reflectance distribution function (BRDF) of land surfaces specifies the behavior of surface directional reflectance as a function of illumination and viewing angles. The Moderate resolution Imaging Spectroradiometer (MODIS) and The Multiangle Imaging Spectroradiometer (MISR) provide their BRDF model parameters products respectively. Since the BRDF model parameters products are inverted from the observations with limited viewing directions for a given pixel, it is necessary to evaluate whether they can effectively characterize the directional reflectance in other viewing directions. In this study, we choose BRDF products data on four land cover types to learn their bidirectional reflectance signatures and to analyze the representation of MISR and MODIS BRDF model parameters products. The results show that: the MISR BRDF product shows hot spot more clearly than MODIS product, and both BRDF models´ representative ability for extrapolating the reflectance at those directions without viewing dada tends to weaken when the viewing zenith angle increases.