Using the algebra transformation method, we develop and demonstrate the use of the δ-P1 approximation to improve steady-state radiative-transfer estimates on spatial scales comparable to the mean free path. We show that the δ-P1 approximation agrees well with Monte Carlo simulation from source to infinity when we choose an appropriate parameter f (fractional portion that scatters directly forward) in the δ-Eddington phase function. We also provide the empirical formula to determine the parameter f.
© 2007 Optical Society of America
Original Manuscript: October 16, 2006
Revised Manuscript: March 7, 2007
Manuscript Accepted: March 29, 2007
Published: July 6, 2007
Vol. 2, Iss. 8 Virtual Journal for Biomedical Optics
Chenggang Chai, Yaqin Chen, Pengcheng Li, and Qingming Luo, "Improved steady-state diffusion approximation with an anisotropic point source and the δ--Eddington phase function," Appl. Opt. 46, 4843-4851 (2007)