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.