aircraft-based augmentation system (location) (ABAS)

An Aircraft-Based Augmentation System (ABAS) is a precision navigation system whose focus is on the integrity ofmeasurement in air traffic rather than on improving accuracy.

The ABAS system incorporates information the aircraft has from other global navigation systems into its calculations. In doing so, the ABAS system can access redundant navigation measurements from Receiver Autonomous Integrity Monitoring( RAIM) for integrity monitoring, or it can access its own onboard sensors for altitude, direction, and airspeed.