Underground imaging using RF tomography: The effect of lateral waves

Abstract

Radio Frequency (RF) tomography is a novel strategy for underground imaging over relatively wide and deep surveillance areas. RF tomography requires a set of low-cost transmitters and receivers deployed randomly on the surface of the ground, or slightly buried. Using the principles of inverse scattering, it is possible to image below ground high contrast dielectric or conducting anomalies, thus revealing buried objects and hidden targets. In RF Tomography, when antennas are buried, or targets are in shallow regions, waves are propagating in proximity of the air-earth interface; therefore, it is necessary to account the Green's function of the half-space and the interference effect of lateral waves. In this paper we introduce an improved inversion scheme that is robust with respect to noise and attenuation due to lossy soils. The effectiveness of this inversion strategy is shown by presenting images reconstructed via synthetic data.