Exploitation of A Ship's Magnetic Field Signatures

Holmes, John J.

doi:10.2200/s00034ed1v01y200605cem009

Cited by 49 publications

(36 citation statements)

References 3 publications

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“…The traditional work in underwater electromagnetic radiation has primarily focused on magneto-static fields (DC fields) arising from interactions between the ferromagnetic steel portions of the ship and earth's magnetic field [1], where this magnetic field can be exploited by magnetic influence mines [2]. Although it is known that there is high attenuation of AC electromagnetic waves for conductive mediums (like seawater) there is a current interest to study AC radiation due to the inclusion of new electric motor propulsor designs and electromagnetic machinery.…”

Section: Introductionmentioning

confidence: 99%

Underwater Electromagnetic Holography Imaging Techniques for Shallow Water Mediums

Valdivia¹,

Williams²,

Alqadah³

2017

PIER B

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Abstract-We propose an approach to characterize the AC underwater radiation produced by a ship over a shallow water medium using dipole sources distributed over an interior surface to the ship. The proposed approach relies on the accurate and efficient representation of dipole sources over the shallow water medium that characterizes the behavior of the electric or magnetic field. The approach is reduced to the solution of the resultant matrix system from the dipole representation. These systems are ill-posed, i.e., if the matrix systems are not solved by special regularization methods, the resultant solution will amplify the measurement noise. The regularization method applied is the least squares QR iterations combined with a new stopping rule that uses a numerical estimate of the measurement noise. Numerically generated data is used to study the validity of the different dipole representations. Finally, we validate our methodology using magnetic measurements that result from degaussing coils of a mid-size vessel.

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Section: Introductionmentioning

confidence: 99%

Underwater Electromagnetic Holography Imaging Techniques for Shallow Water Mediums

Valdivia¹,

Williams²,

Alqadah³

2017

PIER B

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“…Induced magnetism, caused by the movement of ships, planes, and other metallic vehicles within a magnetic field, is one of the main threats to the security of naval vessels [1,2]. It is also a primary factor hindering the development of highprecision magnetic measurement technologies using sensors aboard these vehicles [3].…”

Section: Introductionmentioning

confidence: 99%

An Accelerated 3D-Magnetostatic Field Computation Method With Tetrahedral Surface Integrals

Zhao¹,

Wubing²,

Zhuang³

2017

Proceedings of the 2017 2nd Joint International Information Technology, Mechanical and Electronic Engineering Conference (JIMEC

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An innovative accelerated integral equation method is proposed based on a fast search algorithm for both shared and non-shared faces among mesh elements. This method successfully accelerates the computational process of solving for the tetrahedral coupling coefficients. By using the proposed accelerated integral equation method, the efficiency of constructing the coupling matrix can be improved by more than 40% without decreasing computational accuracy, as demonstrated by analytical solutions, simulations and experimental examples.

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“…Even though its magnitude is much smaller than that of the Earth's magnetic field, it can activate underwater weapon systems equipped with high-sensitivity magnetic sensors, such as influence mines, or underwater detecting equipment. To protect the ship from these threats, it is necessary to establish proper countermeasures against the detection sensors of an influence mine or an underwater detection system [1][2][3][4][5][6][7][8][9].…”

Section: Introductionmentioning

confidence: 99%

A Magnetic Field Separation Technique for a Scaled Model Ship through an Earth's Magnetic Field Simulator

Chung¹,

Yang²,

Jung³

2015

Journal of Magnetics

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This paper presents an experimental technique to accurately separate a permanent magnetic field and an induced one from the total magnetic fields generated by a steel ship, through compensating for the Earth's magnetic field. To achieve this, an Earth's magnetic field simulator was constructed at a non-magnetic laboratory, and the field separation technique was developed, which consisted of five stages. The proposed method was tested with a scaled model ship, and its permanent and induced magnetic fields were successfully extracted from the magnetic field created by the ship. Finally, based on the separated permanent magnetic field data, the permanent magnetization distribution on the hull was predicted by solving an inverse problem. Accordingly, the permanent magnetic fields generated by the ship can easily be calculated at any depth of water.

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Exploitation of A Ship's Magnetic Field Signatures

Cited by 49 publications

References 3 publications

Underwater Electromagnetic Holography Imaging Techniques for Shallow Water Mediums

Underwater Electromagnetic Holography Imaging Techniques for Shallow Water Mediums

An Accelerated 3D-Magnetostatic Field Computation Method With Tetrahedral Surface Integrals

A Magnetic Field Separation Technique for a Scaled Model Ship through an Earth's Magnetic Field Simulator

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