High resolution subsurface imaging of deep targets based on distributed sensor networks

A realistic forward model based on a near-ground distributed sensor grid for a target buried under soil is devised. The soil medium is modeled as a planar stratified medium with a complex dielectric constant profile. The Dyadic Green´s function for multilayer dielectric is used to compute the electric field at the target. A high resolution inversion algorithm based on phase-conjugation approach to detect deeply submerged targets is also presented. The sensor network is setup to enhance the lateral resolution by forming a synthetic aperture. The depth resolution is improved by using bandwidth. So as to improve the efficiency of the search algorithm a soil dielectric model to predict the real and imaginary parts of the dielectric constant from the volumetric soil moisture for a given soil textural composition is extended to the frequency of interest (VHF) resulting in less number of variables.