Bi-directional Reflectance Factor Simulation Of Winter Wheat Canopy Based On Radiositv Model

With the development of science and technology, multi-angle remote sensing ofvegetation catches more and more attention, and has become a hot topic in the field of remotesensing research. The theoretical basis of multi-angle remote sensing of vegetation is plantBRDF (Bi-directional reflectance distribution function) models. By establishing plant BRDFmodels, the structural parameters of the plant could be obtained. The measurement of plantBi-directional reflectance factor (BRF) aims at getting the structural features of the plant fromthe distribution of BRF, thereby the remote sensing data may be analyzed better.In this study, on the basis of the rule of plant growth, a realistic3D scenes of winterwheat is built using Radiosity method（one of computer simulation model）. Based on therealistic3D scenes, canopy Bi-directional reflectance factor (BRF) of winter wheat issimulated, after that, it is analyzed to obtain the distribution of BRF.By simulation we get the distribution of BRF of solar principal plane with shifty zenithangle of observation under different LAI in the visible light or near-infrared wave band. Inorder to analyze the impact of stem components under the different LAI on winter wheatcanopy BRF, the contribution rates of leaf, stem and soil component to canopy Bi-directionalreflectance factor (BRF) are present and calculated. Finally, the effects of differentobservation plane (including principle plane and orthogonal principle plane) and of differentpositions of the sun on canopy BRF are analyzed respectively.