Time-dependent aureole about a source in a multiple-scattering medium

A technique for computing the time-dependent aureole radiance field about a point source in a scattering and absorbing medium is outlined. The experimental feasibility of a time-resolved measurement of this field with narrow field-of-view radiometer is considered. The method proposed here allows a determination of the single-scattering phase function if the optical thickness (product of the direct path length and the scattering coefficient) is less than 0.1. If the optical thickness exceeds 0.5, multiple scattering becomes evident and causes increased broadening of the pulse received by the radiometer. Since the aureole is especially important in the ultraviolet, a numerical simulation of pulse broadening is presented for this spectral region.