Definition
A satellite-based augmentation system (SBAS) operated in Europe that improves the accuracy, integrity, and availability of GPS signals by broadcasting correction and integrity data from geostationary satellites. EGNOS is the European equivalent of the U.S. Wide Area Augmentation System (WAAS) and supports en route, terminal, and approach operations down to LPV minima.
Plain English
EGNOS is Europe's version of WAAS. It listens to GPS signals over Europe, works out the small errors, and sends corrections to aircraft so the GPS position is more accurate and trustworthy enough to use for instrument approaches.
Context Anchor
Seen in discussions of WAAS and other systems that improve satellite navigation for instrument flying.
Derivation
European: the region it serves. Geostationary: the type of satellite used to broadcast corrections, which sits over a fixed point on Earth. Overlay: the corrections are layered on top of the existing GPS signal rather than replacing it. Service: the operational system delivering this to users.
Why Pilots Care
It enables precision GPS approaches with vertical guidance at European airports, improving access and safety during instrument flight.
Grounding Statement
EGNOS does not replace satellite navigation; it adds correction and warning information so the receiver can calculate a more dependable position.
Intuition Check
Do not think of EGNOS as GPS itself. EGNOS is an added European service that improves and monitors satellite navigation signals.
Example Sentence 1
Flying into a regional airport in France, the crew briefed an LPV approach made possible by EGNOS corrections to the GPS signal.
Example Sentence 2
EGNOS signals allowed the crew to maintain accurate position during the IFR arrival into a European airport.