Design of a Test Setup to Measure Magnetic Signature Reduction

Abstract

In order to avoid detection by sea mines, the magnetic signature of merchant and naval vessels can be reduced by running a current through a set of on-board copper coils. This process is called degaussing. Studies have shown that the volume, weight and energy losses of a degaussing system can be reduced by replacing the copper coils with high temperature superconductive (HTS) coils. Moreover, since the technology and production of HTS has matured and the material is highly available, the use of HTS for degaussing coils is a serious option. As a preliminary study towards an HTS degaussing test setup, this paper presents the design of a table-top demonstration with copper degaussing coils. The goal of the demonstration is to measure the magnetic signature and the magnetic signature reduction of a cylindrical object. The design choices of the test setup and the measuring system are discussed. The magnetic signature of the table-top model is calculated as well as the optimal placement of the degaussing coils and the optimal degaussing currents. These results are compared with measurements of the magnetic flux density around the demonstrator.

Magnetic Signature Reduction by Converter Switching Frequency Modulation in Degaussing Systems

“…The degaussing currents are modelled as edge currents along a VOLUME 4, 2016 2D plane. This way of simulating the magnetic signature of a steel object with degaussing coils has been experimentally verified in previous works [7], [8], [14]. The total vector field of the magnetic flux density around the ship, ⃗ B, can then be found by adding the magnetic signature of the hull to the magnetic signature from each degaussing coil as follows:…”