Uniqueness Theorems for the Inverse Problem of Elastodynamic Boundary Scattering

A uniqueness theorem is established for the elastodynamic problemof direct scattering of harmonic small-amplitude waves by anobstacle embedded in an isotropic medium with spatially varyingparameters. Uniqueness theorems are then developed for the inverseproblem of boundary determination of the obstacle associatedwith this direct scattering problem. In particular, it is shownfor nondegenerate elastodynamic problems that knowledge of boththe lamellar and the solenoidal far-field patterns is necessaryto reconstruct the obstacle's boundary.