An Explicit Formula for the Magnetic Polarizability Tensor for Object Characterization

Ledger, Paul D.; Lionheart, William R. B.

Abstract

The magnetic polarizability tensor (MPT) has attracted considerable interest due to the possibility it offers for characterizing conducting objects and assisting with the identification and location of hidden targets in metal detection. An explicit formula for its calculation for arbitrary-shaped objects is missing in the electrical engineering literature. Furthermore, the circumstances for the validity of the magnetic dipole approximation of the perturbed field, induced by the presence of the object, are not fully understood. On the other hand, in the applied mathematics community, an asymptotic expansion of the perturbed magnetic field has been derived for small objects and a rigorous formula for the calculation of the MPT has been obtained. The purpose of this paper is to relate the results of the two communities, to provide a rigorous justification for the MPT, and to explain the situations in which the approximation is valid.

Citation

Ledger, P. D., & Lionheart, W. R. B. (2018). An Explicit Formula for the Magnetic Polarizability Tensor for Object Characterization. IEEE Transactions on Geoscience and Remote Sensing, 56(6), 3520-3533. https://doi.org/10.1109/tgrs.2018.2801359

• Journal Article Type: Article
• Acceptance Date: Mar 29, 2018
• Online Publication Date: Mar 29, 2018
• Publication Date: 2018-06
• Deposit Date: Jun 12, 2023
• Journal: IEEE Transactions on Geoscience and Remote Sensing
• Print ISSN: 0196-2892
• Electronic ISSN: 1558-0644
• Publisher: Institute of Electrical and Electronics Engineers (IEEE)
• Peer Reviewed: Peer Reviewed
• Volume: 56
• Issue: 6
• Pages: 3520-3533
• DOI: https://doi.org/10.1109/tgrs.2018.2801359
• Keywords: General Earth and Planetary Sciences; Electrical and Electronic Engineering