Electromagnetic Induction Spectroscopy

Abstract

An object, made partly or wholly of metals, has a distinct combination of electrical conductivity, magnetic permeability, and geometrical shape and size. When the object is exposed to a low-frequency electromagnetic field, it produces a secondary magnetic field. By measuring the secondary field in a broadband spectrum, we obtain a distinct spectral signature that may uniquely identify the object. Based on the response spectrum, we attempt to “fingerprint” the object. This is the basic concept of Electromagnetic Induction Spectroscopy (EMIS). EMIS technology may be particularly useful for detecting and characterizing buried landmines and unexploded ordnance. EMIS should be fully applicable to many other problems where target identification and recognition (without intrusive search) are important. Potential applications may include industrial sorting processes and robotics.