SBAS is a well-known technology that can augment standalone Global Navigation Satellite Systems such as GPS, GLONASS, Galileo and Beidou in a number of areas including accuracy, integrity and availability. It works by collecting raw positioning data from Continuously Operating Reference Stations (CORS) in the region, computing error corrections (processing and correction) and disseminating these corrections to users by sending these corrections to a geostationary communications satellite via an uplink ground station.

diagramSBAS is currently used in United States (WAAS), Europe (EGNOS), Japan (MSAS), India (GAGAN) and Russia (SDCM) to aid positioning and navigation across many user sectors. The map below shows the footprint of the current SBAS services around the world.