GNSS Based Low-Cost Magnetometer Calibration.

Area of Science:

• Geomatics Engineering
• Sensor Technology
• Navigation Systems

Background:

• Magnetometers are crucial sensors in modern devices, including wearables and vehicles, measuring magnetic fields.
• Traditional magnetometer calibration methods, often requiring multi-sided rotation, are impractical for large objects like vehicles.
• Vehicles possess significant ferromagnetic materials that interfere with magnetic field measurements, necessitating robust calibration.

Purpose of the Study:

• To introduce a novel magnetometer calibration technique for vehicles utilizing Global Navigation Satellite System (GNSS) motion vectors.
• To address the impracticality of conventional calibration methods for vehicle-mounted sensors.
• To enable reliable magnetometer usage within vehicle navigation systems, such as Inertial Navigation Systems (INS).

Main Methods:

• Calibration is performed using the GNSS motion vector derived from the initial part of a vehicle's trajectory.
• The method leverages the azimuth and speed data from GNSS.
• Validation involves comparing GNSS-derived azimuth with the calibrated magnetometer's azimuth over the remaining trajectory.

Main Results:

• The proposed GNSS-based calibration method proved functional for vehicle-mounted magnetometers.
• Vehicle-specific ferromagnetic interference rendered uncalibrated magnetometer data unusable.
• The calibrated magnetometer provided reliable azimuth data for navigation.

Conclusions:

• Magnetometer calibration using GNSS motion vectors is a viable and practical solution for vehicles.
• This method effectively mitigates the impact of ferromagnetic materials on sensor readings.
• The technique enhances the utility of magnetometers in vehicle navigation and INS applications.