Abstract

An algorithm and numerical results are presented for the causal evolution of a radiance field which satisfies the time-dependent radiative transfer equation in a scattering and absorbing medium. Propagation from point to point requires a method of spatial interpolation which does not violate causality, i.e., a method which ensures that the radiance propagates at a predetermined physical speed and not at a speed which is determined by the spatial grid. A causal interpolation scheme is illustrated, and example results for a cylindrically symmetric pulsed beam are presented. This scheme can introduce artificial oscillations which do not affect the long-time behavior of the solution and can be controlled.

© 1987 Optical Society of America