Which sensor primarily serves as a compass by measuring the Earth's magnetic field?

Which sensor primarily serves as a compass by measuring the Earth's magnetic field?

• A. Magnetometer
• B. Barometer
• C. IMU
• D. GPS

Answer: (A)

The magnetometer is the sensor that acts as a compass by reading the Earth’s magnetic field. It detects the magnetic field along three axes, and from those measurements you can determine which direction points toward magnetic north. In a drone, this provides a heading reference that the flight controller can use to keep orientation consistent, even as the vehicle tilts or moves. Other sensors serve different purposes: a barometer measures atmospheric pressure to estimate altitude, GPS gives position and velocity, and an IMU (which includes accelerometers and gyroscopes) measures motion and orientation but does not measure magnetic fields. Because a magnetometer is sensitive to nearby magnetic interference from metal or electronics, it needs calibration and often tilt compensation (using the accelerometer data) or sensor fusion to maintain accurate heading under real-world conditions.

The magnetometer is the sensor that acts as a compass by reading the Earth’s magnetic field. It detects the magnetic field along three axes, and from those measurements you can determine which direction points toward magnetic north. In a drone, this provides a heading reference that the flight controller can use to keep orientation consistent, even as the vehicle tilts or moves.

Other sensors serve different purposes: a barometer measures atmospheric pressure to estimate altitude, GPS gives position and velocity, and an IMU (which includes accelerometers and gyroscopes) measures motion and orientation but does not measure magnetic fields. Because a magnetometer is sensitive to nearby magnetic interference from metal or electronics, it needs calibration and often tilt compensation (using the accelerometer data) or sensor fusion to maintain accurate heading under real-world conditions.