An Automated Indoor Scalar Calibration Method for Three-Axis Vector Magnetometers

In this paper, we propose a new indoor magnetometer calibration system using the 3-D Helmholtz coil. In this method, in order to the use two-step calibration algorithm instead of rotating the sensor in a constant magnetic field vector, the vector rotates around the magnetometer. In other words, a three-axis magnetometer can be calibrated by a zero degrees of freedom system while a shielded Helmholtz coil provides and rotates a constant magnetic field vector. The results of this calibration method will be compared with the classical calibration method in the earth's magnetic field as well. We also present evidence that the magnetometer does not need to align with the Helmholtz coil axis; instead, it can be calibrated with any arbitrary direction of the Helmholtz coil. It is shown that this method can be performed easily and fast in order to calibrate the three-axis magnetometer in an indoor environment. Meanwhile, it can provide almost the same calibration parameters and thermal model for the magnetometer, compared with the classical one.