Use of the delta-P-1 approximation for recovery of optical absorption, scattering, and asymmetry coefficients in turbid media

摘要

We introduce a robust method to recover optical absorption, reduced scattering, and single-scattering asymmetry coefficients (mu(a), mu(s)', g(1)) of infinite turbid media over a range of (mu(s)'/mu(a)) spanning 3 orders of magnitude. This is accomplished through the spatially resolved measurement of irradiance at source-detector separations spanning 0.25-8 transport mean free paths (l*). These measurements are rapidly processed by a multistaged nonlinear optimization algorithm in which the measured irradiances are compared with predictions given by the delta-P-1 variant of the diffusion approximation to the Boltzmann transport equation. The ability of the delta-P-1 model to accurately describe radiative transport within media of arbitrary albedo and on spatial scales comparable to l* is the key element enabling the separation of g(1) from mu(s)'. (C) 2004 Optical Society of America.