A Radiative Transfer Backscatter Model for a Vegetative Layer of a Mixture of Discrete Scatterers

Abstract

Electromagnetic backscattering from a vegetative layer consisting of a mixture of randomly orientated discrete scatterers is modelled using the radiative transfer theory. For simplicity, the layer is assumed to be bounded at the bottom by a planar half-space. Circular disks are used to model the leaves while prolate ellipsoids are used to model the stems and small branches. The integro-differential equations are then solved using an iteration method. A first order solution is explicitly given. The results are compared with measurements from fields of soybean, corn, wheat and milo. To show the interactions between scatterers, a second order solution for a half-space of mixed scatterers is also given. It is found that interactions between scatterers appear in the form of extinction coefficients and cross products of phase matrices of the components of the mixture.