For a system consisting of a random medium with rough boundaries, the
governing (Bethe-Salpeter) equation for boundary-value transport
problems can be written in a form such that the medium and the
boundaries are treatedon an equal footing. This enables several
expressions for the solution to be obtained by interchanging the roles
of the medium and the boundaries, thus allowing the most convenient one
to be selected according to the specific situation and the information
required. This book presents a unified theory based on the
Bethe-Salpeter equation with particular attention being paid to:
boundary-value problems of transport, layer problems, a fixed scatterer
imbedded in a bounded random medium, construction of an optical
scattering matrix for a complete system, and optical wave propagation in
a turbulent medium. The last topic is treated in terms of first moment
equations combined with the cluster expansion and, second, the two-scale
method based on the Lagrange variational principle.