“…For a complete review of most important papers, the reader is referred to [26]. This causes a systematic error in the solution, which grows with the optical path length of the radiation, and prevents the application of the SAA solution to certain nonstationary RTE problems, where the time dispersion is the principal effect [24,27]. If the SAA solution is used in the scheme of rigorous calculation of the radiation field as the sum of the anisotropic and diffuse parts L ¼ L a þ L D [10], a large part of anisotropic radiance appears to be included in the diffuse component L D .…”