Narrow-beam propagation in a two-dimensional scattering medium.

The problem of narrow-beam propagation in a medium with highly anisotropic scattering is considered within radiative transfer theory. A novel solution of the radiative transfer equation within small-angle approximation, accounting for the path length spread, is presented. A new stable numerical algorithm for the simulation of a narrow beam is developed and applied to a narrow beam in a two-dimensional scattering medium. A truly three-dimensional version of the proposed approach is formulated.