  The problem of recovering the asymptotics of a short range perturbation of
the Euclidean Laplacian on n dimensional Eudlidean space from fixed energy
scattering data is studied. It is shown that for greater than or equal to three
that a magnetic potential is determined, modulo Gauge invariance, by its
scattering matrix at a fixed non-zero energy. This result also holds for a wide
class of scattering manifolds.
