  With its roots in kinetic theory, the lattice Boltzmann method (LBM) cannot
only be used to solve complex fluid flows but also radiative transport in
volume. The present work derives a novel Fresnel boundary scheme for radiative
transport LBM, based on Fresnel's equation, which depicts the partly reflected
radiation on surfaces. Driven from a boundary modeling and discussion on the
microscopic level, incorporating Fresnel's equation, it is developed a boundary
model for the mesoscopic radiative transport LBM. At an intermediate step, the
Fresnel's equation is related to well known partial differential (Robin)
equations, based on a bottom-up approach where the P1-Approximation is
deployed. To connect the novel boundary scheme to the so derived target
equation, a Chapman-Enskog expansion is examined in addition. Both techniques
together, point out how to interpret microscopic modeling by the means of
macroscopic expressions and as a consequence how, to chose simulation
parameters according to the specific boundary. The numerical tests suggest that
the proposed boundary is first order convergent. The paper closes with a
showcase, where the novel boundary method for radiative transport LBM is
applied to a setup with multiple LED spots.
