Backscattering of nonlinear acoustic impulses from buried inclusions in granular beds

Nonlinear acoustic impulses travel as weakly dispersive bundles of energy through 3-D, dry, granular assemblies. Such impulses can therefore be exploited to probe for buried objects in 3-D granular assemblies. In this article, we shall discuss the details of propagation of an impulse generated at the surface of a granular bed. The role of polydispersity will be briefly addressed. The calculations suggest that backscattered data, as received at predetermined locations at the surface, may be helpful in reconstructing an approximate image of the buried inclusion, as viewed from above.