A hotspot function in a simple bidirectional reflectance model for satellite applications

The model presented here is an improvement over the semiempirical model of Roujean et al. [1992] for estimating the bidirectional reflectance from vegetation. Roujean's model has been considered for global applications because of its simplicity and the underlying physics. However, the model does not adequately describe the hotspot near the Sun's illumination direction. In this paper, a hotspot kernel based on a canopy gap size distribution …