The United States’ Global Positioning System (GPS) offers a single frequency service to many aviation systems and applications, including:
- performance-based navigation (PBN);
- automatic dependent surveillance-broadcast (ADS-B);
- aircraft systems, such as terrain avoidance warning systems (TAWS).
In the future, Dual Frequency Multi Constellation services (DFMC) combining dual frequency signals from the United States’ GPS, the Russian Federation’s GLONASS, Europe’s Galileo and China’s BeiDou will help aviation both enhance its performance and benefit from additional robustness.