The Study On Thermal Infrared Emission Directionality Of Typical Soil-vegetation Canopy Based On 3-D Structure Simulation Model

As key environmental factor land surface temperature has too much relativity with human life. It's significant to study the distribution and change by remote sensing. Due to the anisotropy of land surface thermal radiation, it's necessary to make clear the mechanism of directional distribution of thermal infrared emission before we can get more reliable temperature information of observed objects.From many the directional models, the 3-D real structure model are used in this paper based on computer graphics. Firstly, we achieve the 3-D real structure simulation of typical crop canopies. Different from similar real structure models, we primarily consider the soil roughness. Also we design a simple means accomplish the roughness measurement and simulation of soil. Secondly, we transplant a calculation system —RGM (Radiosity-Graphics combined Method) from Unix Workstation to PC. Then we modified the RGM to calculate both scene's BRDF and thermal infrared radiance. We can conveniently simulate scenes composed of various types of soils and crop canopies.Theoretical analysis shows that factors related to thermal infrared directionality include emissivity's directional difference of material, component temperature distribution, multi-scattering caused by canopy structures and the components proportion's change along with the view direction. Real structure models has born advantage to deal with multi-scattering and components proportion's change, so we take an emphasis on the way to decide the components' temperature. 4-heft means and Cupid model are introduced in this paper.