Although all satellite-based augmentation systems (SBAS) are regional systems, it is important to ensure that they are compatible and that SBAS providers cooperate with each other and coordinate their actions.
In addition to GAGAN, three other regional systems of note exist:
WAAS (Wide Area Augmentation System): The United States Federal Aviation Administration leads the development of WAAS, which covers the US and Canada.
MSAS (MTSAT Satellite-Based Augmentation System): The Japanese Civil Aviation Bureau is implementing the MSAS which will cover the Flight Instrument Rules region of Japan.
EGNOS:The European Geostationary Navigation Overlay Service (EGNOS) is Europe’s first venture into satellite navigation. It augments the positioning signals provided by the USA’s GPS global navigation satellite system and makes them suitable for safety critical applications such as flying aircraft or navigating ships through narrow channels.
Compatibility makes each system more effective and ensures that all the systems can be integrated into a seamless worldwide navigation network. Cooperation on SBAS is currently coordinated through the Interoperability Working Groups for GAGAN, MSAS, EGNOS and WAAS.