A standardized excitation approach for classification of buried UXO

In this paper, a new discrimination procedure is presented to enhance classification of buried metallic object. This algorithm is based on a standardized source set (SSS) approximation, applicable for an arbitrary highly conducting and permeable metallic objects placed in a low frequency (from 10´s of Hertz up to several 100´s of kHz) time varying electromagnetic field. The method treats accurately all near field, heterogeneity, and internal interaction effects. In the SSS approach, any input primary magnetic field is represented as a sum of magnetic fields produced by a set of sources distributed over on an auxiliary surface outside the fictitious surface. The object´s response corresponding to unit amplitudes of any of these input field sources is likewise quantified in terms of a set of (responding) sources, which can be derived from measured data. Thereafter, the object´s response to any excitation can be expressed just by different superpositions of these standardized inputs. The spatial distribution and frequency dependence features of responding equivalent sources are analyzed and used for target discrimination. The numerical results are given for an actual unexploded ordinance (UXO)