Measured dipole expansion of discrete relaxations to represent the electromagnetic induction response of buried metal targets

Broadband electromagnetic induction (EMI) sensors have been shown to be able to reduce false alarm rates and increase the probability of detecting landmines. To aid in the development of these sensors and associated detection algorithms, a testing facility and inversion technique have been developed to characterize the response of typical targets and clutter objects as a function of orientation and frequency. The models are simple sets of magnetic dipoles with discrete relaxation frequencies. Results will be presented for a range of targets such as shell casings, wire loops, and landmines. It is envisioned that the models derived in this work will be utilized to reduce false alarm rates and increase the probability of detection for EMI sensors through improvements in both the hardware and the processing algorithms used to detect and discriminate buried targets.