  We study analytically and numerically field/intensity correlations in wave
transport through volume-disordered waveguide. The obtained channel and spacial
correlations deviate from those found in framework of
Dorokhov-Mello-Pereyra-Kumar (DMPK) formalism, that we relate to
inapplicability of equivalent channel approximation in DMPK. We show that this
can be remedied by introducing boundary correction -- an escape function which
depends on the waveguide geometry -- that describes wave transport near a
boundary between random medium and free space. We obtain the expressions for
field/intensity channel and spacial correlation functions which agree with the
numerics and are consistent with the perturbative expressions in slab geometry
as well as experiments conducted in Q1D.
