Research on 3D canopy´s reflectance model of semi-arid grassland

In this paper, a model for light interaction has been developed to compute bidirectional reflectance from realistic 3D canopies approximated by an arbitrary configuration of plants. It can well simulate multi-spectral reflectance of semi-arid nature grassland. There are two important parts of the simulation model. The first part is the generation of the 3D realistic grassland scene. In this model, the Clumped Architecture Model of Plants (CLAMP) is used to. The second part is the determining the visibility and brightness of grass canopy scene using Geometric Optics Model. The simulating model is validated by comparing the simulation result with the HJ satellite data at synchronous time. As a result, it can describe directional reflectance properties of semi-grassland canopies in terms of canopy architecture parameters and optical scattering properties of discrete phytoelements.