Investigation of ELF Signals Associated with Mine Warfare: A University of Idaho and Acoustic Research Detachment Collaboration, Phase 2

Extremely low frequency ELF electromagnetic signals are used by enemy combatants to detect and, subsequently, to incapacitate, by means of surface and subsurface mines, naval vessels. The questions that are being asked in this investigation are 1 once an ELF signal is generated, how far will it propagate and still be detectable and 2 how can such signals be modeled, excited and measured To this end, the scenario considered is one in which an ELF source of the electric or magnetic kind is located in or above water, such as a lake or ocean. This source stimulates an ELF signal that is free to propagate in the water and air, and is reflected by various material interfaces. For purposes of experimental demonstration, the investigation focuses on the scenario of ELF sources and signals in the context of Lake Pend Oreille, where the Acoustic Research Detachment ARD, Bayview, Idaho is located. The research program was designed with two major thrusts Modeling and experimentation. The modeling thrust was coordinated and executed by the University of Idaho UI, Moscow, Idaho the experimentation thrust was coordinated and executed by ARD.