Which system uses satellites to calculate the aircraft's speed over ground, headings, and rate of climb?

Which system uses satellites to calculate the aircraft's speed over ground, headings, and rate of climb?

• A. Inertial Measurement Unit
• B. Barometer
• C. Magnetometer
• D. Global Positioning System

Answer: (D)

Satellites enable a navigation system to determine an aircraft’s precise position, which in turn lets us compute speed over the ground and the direction the aircraft is moving. The Global Positioning System is the satellite-based system that provides these measurements by using signals from a network of GPS satellites. By comparing changes in position over time, it derives groundspeed and track (heading). It can also infer vertical motion, or rate of climb, from how altitude changes with time using GPS-derived altitude data (though vertical speed is often supplemented by barometric data for accuracy). The other sensors don’t rely on satellites: an inertial measurement unit uses internal accelerometers and gyros to track motion without external references; a barometer measures air pressure to estimate altitude and vertical speed relative to the air; a magnetometer determines heading from the Earth’s magnetic field but doesn’t provide position or velocity via satellites.

Satellites enable a navigation system to determine an aircraft’s precise position, which in turn lets us compute speed over the ground and the direction the aircraft is moving. The Global Positioning System is the satellite-based system that provides these measurements by using signals from a network of GPS satellites. By comparing changes in position over time, it derives groundspeed and track (heading). It can also infer vertical motion, or rate of climb, from how altitude changes with time using GPS-derived altitude data (though vertical speed is often supplemented by barometric data for accuracy). The other sensors don’t rely on satellites: an inertial measurement unit uses internal accelerometers and gyros to track motion without external references; a barometer measures air pressure to estimate altitude and vertical speed relative to the air; a magnetometer determines heading from the Earth’s magnetic field but doesn’t provide position or velocity via satellites.