Magnetometer

A magnetometer is a sensor used in inertial navigation systems (INS) to measure the Earth’s magnetic field and determine heading (direction relative to magnetic north). It is commonly used in IMUs (Inertial Measurement Units) to complement gyroscopes and accelerometers, improving navigation accuracy in aircraft, drones, submarines, and land vehicles.

How a Magnetometer Works in INS?

  1. Detects Magnetic Field Strength & Direction – Measures Earth’s magnetic field in three axes (X, Y, Z).

  2. Determines Heading – Calculates the object’s orientation relative to magnetic north.

  3. Aids INS & GNSS Navigation – Used for heading correction and drift compensation in combination with gyroscopes.

Applications of Magnetometers in INS

Drones & UAVs – Assists with orientation and course stabilization.

Marine & Submarine Navigation – Provides heading information when GNSS is unavailable.

Land Vehicles & Military Systems – Helps with navigation in GPS-denied environments.

Challenges of Using Magnetometers in INS

Magnetic Interference – Nearby electronics or metal structures can distort readings.

Not as Accurate as Gyroscopes – Used primarily for heading estimation, not precise attitude control.

Advantages of Using Magnetometers in INS

Low Power Consumption – Ideal for battery-operated navigation systems.

Provides Absolute Reference – Unlike gyroscopes, which drift over time, a magnetometer always detects magnetic north.

Enhances Sensor Fusion – Combined with IMU and GNSS, it improves navigation accuracy.