# A Magnetic Field Camera for Real-Time Subsurface Imaging Applications

## TL;DR

This paper presents a real-time magnetic field imaging device using an array of magnetometers, capable of visualizing subsurface objects and power-line currents with high spatial and temporal resolution.

## Contribution

The authors developed a portable magnetic field camera that provides real-time, high-resolution imaging of magnetic field distributions for subsurface and electrical applications.

## Key findings

- Successfully mapped hidden objects using magnetic field images
- Demonstrated imaging of power-line currents at 50 Hz
- Achieved real-time visualization with high spatial resolution

## Abstract

We have constructed an imaging device that capable to show a spatio-temporal distribution of magnetic field intensity in real-time. The device employs a set of AMR (Anisotropic Magneto Resistance) 3-axis magnetometers, which are arranged into a two-dimensional sensor array. All of the magnetic field values measured by the array are collected by a microcontroller, which pre-process and send the data to a PDU (Processing and Display Unit) implemented on a smartphone/tablets or a computer. An interpolation algorithm and display software in the PDU present the field as a high-resolution video; hence, the device works as a magnetic field camera. In the experiments, we employ the camera to map the field distribution of distorted ambient magnetic field induced by a hidden object. The obtained image of field shows both the position and shape of the object. We also demonstrate the capability of the device to image a loaded power-line cable carrying a 50~Hz alternating current.