A computationally efficient canopy reflectance model is developed. A typica
l two-layer canopy of forest understory communities is addressed in the mod
el where a geometrically thin layer of vegetation of different structure an
d/or optical properties is under the main layer of canopy. The model allows
to calculate reflectance spectrum in every given direction for the spectra
l range 400-2500 nm. The model calculations show that the use of effective
canopy parameters in a homogeneous canopy reflectance model may cause signi
ficant biases in estimated canopy reflectance. (C) 2001 Elsevier Science Lt
d. All rights reserved.