Objective

Photo of the prototype system.

Building on an earlier SERDP SEED project (MR-1174), this project sought to design an optimum active electromagnetic (EM) system that can extract, from the measurements, the best possible estimates of the location, depth, size, shape and metal content of a buried metallic object in the presence of the interfering response of non-unexploded ordnance (UXO) metallic objects. Discrimination can be achieved through selective filtering of the response inherent to the system design followed by post acquisition data processing. The parameters of the object are obtained by an inversion of the measurements to establish the principal EM moments of the detected object. These are never determined perfectly because of a fundamental non-uniqueness in the solutions (the response of the target) to the governing diffusion equation. Limitations introduced by depth of the target, the response of the ground, and the presence of other non-UXO metallic objects combine with constraints of weight and power considerations to restrict what is achievable. An optimum system is bounded by these theoretical and practical considerations and, in the end, represents a compromise that detects, discriminates, and classifies to an agreed upon specification.

The project performed basic research to develop a systematic approach for the design and fabrication of an optimum active EM system based on the methodology employed in the minerals exploration industry in the search for metallic ore bodies. The intent of the optimum system, bounded by practical and theoretical limitations, is to detect, discriminate, and classify buried ordnance.