Location estimation using a broadband electromagnetic induction array

Abstract

A broadband quadrapole electromagnetic induction (EMI) array with one transmitter and three receiver coils is built for detecting buried metallic targets. In this paper, it is shown that the locations of multiple metallic targets including their depth and cross-range position can be estimated accurately with the EMI array using an orthogonal matching pursuit (OMP) approach. Conventional OMP approaches use measurement dictionaries generated for each possible target space point which results in huge dictionaries for the 3D location problem. This paper exploits the inherent shifting properties of the scanning system to reduce the size of the dictionary used in OMP and to lower the computation cost for possibly a real-time EMI location estimation system. The method is tested on both simulated and experimental data collected over metal spheres at different depths and accurate location estimates were obtained. This method allows EMI to be used as a pre-screener and results in valuable location estimates that could be used by a multi-modal GPR or other sensor for enhanced operation. © 2009 SPIE.