Average crossing parameter and forward scattering ratio values in four-flux model for multiple scattering media (vol 194, pg 251, 2001)
Résumé
The four-flux model for multiple scattering media allows one to evaluate scattering properties (reflectances, transmittances) by using simple formulae which may even be readily handled by pocket calculators. Unfortunately, it involves parameters ϵ, called the average crossing parameter, and ζ, called forward scattering ratio, which cannot be a priori evaluated in the framework of the four-flux model, excepted in special cases (collimated radiation or semi-isotropic diffuse radiation). It however happens that the four-flux model can be extended to larger fields of applications if the average crossing parameter and the forward scattering ratio, originally defined as physical quantities, are viewed adjustable parameters. This paper is devoted to the evaluation of these free parameters, allowing one to carry out more accurate four-flux computations.