Inversion scheme for ground penetrating radar that takes into account the planar air-soil in interface

A three-dimensional (3-D) diffraction-tomographgy inversion scheme that tak es into account the planar air-soil interface is derived for fixed-offset g round penetrating radar (GPR), The inversion scheme is based on a plane-wav e expansion of the dyadic Green's function for the interface problem and th e first Born approximation. It can be implemented efficiently with fast Fou rier transforms. Numerical examples demonstrate the importance of taking in to account the air-soil interface and the ability of the inversion scheme t o locate strong scatterers such as metal pipes.