Modeling a Ship’s Ferromagnetic Signatures

Ferromagnetic models of ships and submarines that predict or reproduce their magnetic signatures have found applications in the development of both offensive and defensive military systems from World War II to the present. The mathematical basis of generalized coordinate systems will be presented and demonstrated with example applications to analytic spherical and prolate spheroidal magnetic ship models. In addition, the advantages and pitfalls of using complex finite-element- and boundary-element numerical techniques to predict high-order near-field ship signatures will be discussed, followed by a short description of the design and testing of complementary physical scale models. Extrapolation of measured magnetic signatures from testing environments to threat areas using semi-empirical math models will be presented, along with an explanation of their inherent instabilities and methods for regularizing them. These magnetic ship signature modeling techniques are used today in designingoptimized signature reduction systems that have a minimum impact on ships and their systems. The discussion will be closed with an important discussion of the verification and validation of magnetic models of surface ships and submarines.

Introduction.- Basic Equations.- First-Principal Models.- Semiempirical Models.- Summary.

Dr. John J. Holmes received his B.S. (1973), M.S. (1974), and Ph.D. (1977) degrees in electrical engineering from West Virginia University. He joined the Naval Surface Warfare Center (1977) and is currently the Senior Scientist for the Underwater Electromagnetic Signatures and Technology Division, where he is responsible for the development of underwater electromagnetic field signature reduction systems for surface ships and submarines. Dr. Holmes has written 24 peer-reviewed papers, holds 10 patents, received the David Packard Excellence in Acquisition Award (1999), the Meritorious Civilian Service Award (1986), and is a senior member of the Institute of Electrical and Electronic Engineers.