Specialty Ground Reference Receivers
The US Federal Aviation Administration (FAA) developed the Wide Area Augmentation System (WAAS) to improve the position accuracy of GPS receivers and to add a certified level of integrity to the aviation industry. WAAS corrects for GPS signal errors caused, for example, by ionospheric disturbances and satellite orbit errors and relays integrity information regarding the health of each GPS satellite. Corrupted signals can be eliminated from a GPS solution. WAAS corrections are available free of charge to civilian users in North America.