Which system uses satellites rather than ground-based transmitters for location information?

• A. Global Navigation Satellite System (GNSS)
• B. Ground Positioning System (GPS)
• C. Global Positioning System (GPS)
• D. GPWS

Answer: (C)

Location information obtained from satellites is provided by the Global Positioning System, which uses a network of orbiting satellites that broadcast precise timing signals. A receiver on the aircraft reads signals from multiple satellites, measures how long each signal took to arrive, and then triangulates the position from those distances. This satellite-based method is what sets GPS apart from systems that rely on ground-based transmitters. Note that GNSS is the broader family that includes GPS, but GPS is the specific system referred to in the question. GPWS isn’t a satellite-based positioning system; it’s a terrain awareness and warning system.