Adapted from RAMI site
The FLIGHT model (v.6.3) is based on Monte Carlo simulation of photon transport (North, 1996; Disney et al., 2000; Barton and North, 2001), and has been developed to simulate the observed reflectance response of three-dimensional vegetation canopies. Evaluation of bidirectional reflectance is achieved by simulation of the photon free-path within a canopy representation, and simulation of the chain of scattering events incurred by a photon in its path from the source to the receiver or to its absorption. Multiple scattering between different foliage elements and with the ground is thus modelled. Foliage is approximated by structural parameters of area density, angular distribution, and size, and optical properties of reflectance and transmittance. Leaves are approximated as bi-Lambertian scatters, and the angular distribution of incident diffuse light may be modelled explicitly.
North, P. R. J.(1996), Three-dimensional forest light interaction model using a Monte Carlo method, IEEE Transactions on Geoscience and Remote Sensing, 34, 946.956.
Disney, M. I., Lewis, P., & North, P. R. J. (2000). Monte Carlo ray tracing in optical canopy reflectance modelling. Remote Sensing Reviews, 18(2 – 4), 163 – 196.
Barton, C.V.M. and North, P.R.J., (2001). Remote sensing of canopy light use efficiency using the photochemical reflectance index: model and sensitivity analysis. Remote Sensing of Environment, 78, 164-273.