A fast, invertible canopy reflectance model

Taking advantage of positive features of the Nilson-Kuusk and the SAIL canopy reflectance (CA) models, a new fast CR model has been developed. The new model considers the diffuse and specular reflection of shortwave radiation on leaves, the canopy hot spot, and nonlambertian soil. Diffuse fluxes are treated in a four-stream approximation. An elliptical distribution has been used for leaf inclination. Comparisons of the models demonstrate a good agreement. The complete set of algorithms of the new model is appended.