Inverse-scattering methods for three-dimensional targets buried in the lossy earth

New diffraction tomographic (DT) algorithms for imaging three-dimensional (3D) buried objects are presented using electric and magnetic dipoles as transmitters and receivers, respectively, where the air-earth interface is taken into account. A general asymptotic formulation is developed to evaluate the Sommerfeld integrals, which is valid for any buried depth and measurement height. These algorithms are directly derived based on a lossy background and can be used by lower-frequency systems, from which objects deeply buried in the earth can be detected. Reconstruction examples are given to show the validity of these algorithms.