Solution of Linear Radiative Transfer Problems in Plane-Parallel Atmospheres. III

This paper examines the problem of determining the statistical averages describing the diffusion of radiation in an inhomogeneous plane-parallel atmosphere. The method of invariant imbedding is used to find the mean number of scattering events and the average traveling time of different groups of photons in the medium. In all cases the problem reduces to solving integro-differential equations of the same form with specified initial conditions, which is easy to realize by numerical calculation.