Vegetation Tadiative Transfer Based on Virtual Flux Decomposition.
FDM is one-dimension model based on SAIL++ model.
Vegetation radiative transfer modeling based on virtual flux decomposition,
Journal of Quantitative Spectroscopy and Radiative Transfer, 111, 1389-1405, doi:10.1016/j.jqsrt.2010.02.010.
Extension of virtual flux decomposition model to the case of two vegetation layers: FDM-2,
Journal of Quantitative Spectroscopy and Radiative Transfer, 113, 440-460, doi:10.1016/j.jqsrt.2012.01.003.