Magnetic Source Localization Based on Magnetic Dipole-Array Method for Demagnetizing Field Estimation

Abstract

In this study, we address magnetic source localization under conditions where both the source and magnetic sensors are placed close to magnetic shielding material. In such environments, the magnetic field generated by the magnetic source is distorted by demagnetizing fields induced by the magnetic shielding material, leading to degradation of estimation accuracy. To address this problem, we apply the magnetic dipole-array method (MDM), previously proposed to account for the influence of demagnetizing fields, to magnetic source localization. In addition, we design a cylindrical magnetic dipole array specifically for cylindrical magnetic shields, in contrast to the planar dipole-array configurations for rectangular magnetic shields used in our previous studies. Experiments of magnetic source localization using coils, room-temperature magnetic sensors, and a compact cylindrical magnetic shield were conducted. The results showed that the proposed method improved the estimation accuracy, reducing the average position error from 2.7 to 0.59 mm compared with conventional approaches that do not account for demagnetizing fields. This study provides a fundamental investigation under controlled experimental conditions as a basis for future application of MDM to biomagnetic measurements.