Which sensor acts as a compass by measuring the magnetic field around the aircraft?

Which sensor acts as a compass by measuring the magnetic field around the aircraft?

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

Answer: (D)

Measuring the Earth's magnetic field along three axes gives a heading reference, which is exactly what a compass does. The magnetometer is the sensor that detects magnetic field strength and direction, allowing the flight controller to determine which way the aircraft is facing relative to magnetic north. Barometers monitor air pressure to estimate altitude, not direction. GPS provides position and motion information from satellites and can infer course over ground, but it doesn't directly measure magnetic orientation. An IMU tracks movement and orientation changes using accelerometers and gyroscopes, but for reliable magnetic heading it relies on the magnetometer data; without it, heading would drift. Magnetic readings can be distorted by nearby electronics or ferrous materials, so calibration (adjusting for distortions) helps keep heading accurate.

Measuring the Earth's magnetic field along three axes gives a heading reference, which is exactly what a compass does. The magnetometer is the sensor that detects magnetic field strength and direction, allowing the flight controller to determine which way the aircraft is facing relative to magnetic north. Barometers monitor air pressure to estimate altitude, not direction. GPS provides position and motion information from satellites and can infer course over ground, but it doesn't directly measure magnetic orientation. An IMU tracks movement and orientation changes using accelerometers and gyroscopes, but for reliable magnetic heading it relies on the magnetometer data; without it, heading would drift. Magnetic readings can be distorted by nearby electronics or ferrous materials, so calibration (adjusting for distortions) helps keep heading accurate.