Magnetometers for drone heading and magnetic surveys
Updated November 3, 2026
A magnetometer measures the magnetic field. On drones it serves two very different purposes: giving the flight controller a heading reference from the Earth’s field, and carrying out magnetic surveys in which the field itself is the data being collected.
Navigation magnetometers
Three-axis MEMS or magnetoresistive sensors give heading for the autopilot and INS. Their main problem is not the sensor but the aircraft: motors, high currents, steel parts and electronics distort the field. Good practice is to mount the magnetometer away from power cables and motors, often on a mast, and to calibrate it in the final installation.
Survey magnetometers
Geophysical and detection payloads measure tiny variations of the field to locate minerals, pipelines, unexploded ordnance or archaeological structures.
- Fluxgate magnetometers: vector measurements, robust and relatively low cost.
- Optically pumped magnetometers (caesium, potassium, helium): very high sensitivity, measuring the total field.
- Mounting: towed bird or boom to keep the sensor away from the drone’s magnetic noise.
- Compensation: software that removes the drone’s own magnetic signature from the data.
Key specifications
- Sensitivity and noise floor.
- Sampling rate, matched to flight speed and survey line spacing.
- Heading error and dead zones for optically pumped sensors.
- Integration: GNSS time-tagging, data logging and compensation.
- Mass and power, especially for towed systems.
Heading can also come from dual-antenna GNSS receivers or high-grade IMUs, which do not suffer from magnetic interference.
