A Joint Vision of Infrastructure Strategy for Resilient Navigation in the Airspace

Aeronautical navigation services supported by Global Navigation Satellite Systems (GNSS) have enabled a new generation of navigation procedures that offer improved precision and efficiency. GNSS supports a variety of procedures in various operating environments, like oceanic, enroute, terminal, approach and landing, as well as in airport environments; all of these procedures are conceived as overlays, meaning that they follow the same ground tracks as operations established before GNSS. A more recent type of service, like Required Navigation Performance (RNP), leverage GNSS augmentation services to support such airspace design flexibility, which will ultimately result in better efficiency. By supporting RNP, GNSS services can support new safe and efficient operational procedures that minimize Air Traffic Control (ATC) and pilot workload and support a higher degree of autonomy to aircraft. While the capabilities and use cases for GNSS services have expanded rapidly over the last two decades, the resilient, complementary means of navigation based on terrestrial radionavigation have not received the same levels of support, partly due to a lack of research and investment, but mainly because of the apparent continuing belief by some that with enough satellites, signals, and orbits, GNSS can become the sole means of deriving all position, navigation, and timing services. Efforts to “re-establish” the requirement for resilient and complementary PNT systems has once again become a priority, according to Appendix C of Resolution A41-8 (ICAO 2022). This is, in part, the result of a growing call for action and increasing numbers of interference events worldwide that have impacted the safety, security, and efficiency of air transportation.