A new–generation EM system for the detection and classification of buried metallic objects

A prime requirement in discrimination between UXO and non-UXO metallic fragments (clutter) is to determine accurately the response parameters that characterize a metallic object in the ground. Lawrence Berkeley National Laboratory has been involved in assessing and comparing existing systems, and designing an optimum system for UXO detection. A prototype of a new electromagnetic system will be built based on the results of this study. The detection and characterization of metallic objects can be considered a two-step process: location and identification. A multi-component transmitter-receiver system is essential for the identifying of the principal dipole moments of a target. The ground response imposes an early time limit on the time window available for target discrimination. Once the target response falls below the ground response, it will be poorly resolved, especially since the ground response itself will be variable due to the inhomogeneous nature of the near surface. For a given range of targets and given ambient noise characteristics, one can optimize system bandwidth so as to maximize the observable signal-to-noise ratio. A sensor with four or more decades of flat frequency response is needed to record the secondary magnetic fields associated with the target.