What device on a UAS determines the roll, pitch, and yaw of the aircraft?

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

Answer: (B)

Roll, pitch, and yaw describe how the aircraft is oriented around its three axes. To determine these angles, a UAS uses an inertial measurement unit that contains gyroscopes and accelerometers. Gyroscopes measure how fast the aircraft is rotating about each axis, while accelerometers sense linear acceleration and help identify the direction of gravity for roll and pitch. By fusing these measurements over time, the flight controller computes the current orientation: roll, pitch, and yaw. Yaw can drift without a reference, so a magnetometer often provides heading reference to correct it, but the device that gives the orientation data is the IMU. Barometers and GPS provide altitude and position, not orientation.