Principles of the radiosity method versus radiative transfer for canopy reflectance modeling

The radiosity method is introduced to plant canopy reflectance modeling. The authors review the physics principles of the radiosity method which originates in thermal radiative transfer analysis when hot and cold surfaces are considered within a given enclosure. The radiosity equation, which is an energy balance equation for discrete surfaces, is described and contrasted with the radiative transfer equation, which is a volumetric energy balance equation. Comparing the strengths and weaknesses of the radiosity formulation with those of the radiative transfer formulation for canopy reflectance modeling, it is concluded that both methods are complementary to each other. Results of a sample calculation are given for a simplified canopy model with 4000 leaves