  In this investigation the boundary value problem of light propagation in the
gravitational field of one arbitrarily moving body with monopole structure is
considered in the second post-Newtonian approximation. The solution of the
boundary value problem comprises a set of altogether three transformations: k
-> sigma and sigma -> n and k -> n. Analytical solutions of these
transformations are given and the upper limit of each individual term is
determined. Based on these results, simplified transformations are obtained by
keeping only those terms relevant for the given goal accuracy of 1
nano-arcsecond in light deflection. Like in case of light propagation in the
gravitational field of one body at rest, there are so-called enhanced terms
which are of second post-Newtonian order but contain one and the same typical
large numerical factor. Finally, the impact of enhanced terms beyond 2PN
approximation is considered. It is found that enhanced 3PN terms are relevant
for astrometry on the level of 1 nano-arcsecond in light deflection, while
enhanced 4PN terms are negligible, except for grazing rays at the Sun.

General Relativity and Quantum Cosmology