ground-based augmentation system (GBAS)
local area augmentation system (LAAS)
The augmentation to the global positioning system (GPS) to meet Cat I, Cat II, and CAT III precision approach accuracy, integrity, continuity, and availability requirements. The system is ground-based and comprises a ground reference station at or near an airport. The airborne system has only a top incorporate differential correction capability as well as a link with the ground reference station for receiving correctional data. Also known as DGPS (differential global positioning system) and ground-based augmentation system (GBAS). See differential GPS.