GPS (Global Positioning System)

GPS (Global Positioning System) is a satellite-based radio navigation system operated by the United States that provides accurate position, velocity, and time information to equipped receivers anywhere on or near the Earth. It has become the primary navigation source for modern aviation.

• Constellation of 31+ satellites in medium Earth orbit (~20,200 km altitude)
• Standard positioning accuracy: ~3–5 meters laterally
• Aviation GPS receivers must be TSO-certified (e.g., TSO-C129, TSO-C145/C146 for WAAS)
• WAAS/EGNOS/MSAS provide differential corrections for precision approach capability
• RAIM (Receiver Autonomous Integrity Monitoring) detects satellite failures
• Backup systems essential — GPS is vulnerable to jamming and solar activity