What is a Wide Area Augmentation System?

Wide Area Augmentation System (WAAS) is a Satellite Based Augmentation System (SBAS) put in place by the Federal Aviation Administration (FAA) and the Department of Transportation (DOT) for the US Airspace. Wide Area Augmentation System compliments GPS by improving the accuracy of information by correcting errors in signals with the help of accurately positioned reference points or ground stations. This system helps GPS overcome its disadvantages in respect to accuracy, integrity, continuity and availability with the help of external information.

WAAS is primarily deployed for civil aviation applications to provide accurate and precise navigation capabilities to aircrafts for en route navigation, airport departures, and airport arrivals. It provides horizontal and vertical navigation for landing approach operations, particularly in low-visibility situations.

WAAS currently covers only North America as there are no ground reference stations for this technology in other countries yet. Other international SBAS systems are GAGAN in India, EGNOS in Europe, and MSAS in Japan.