Abbreviated as WAAS, Wide Area Augmentation System is a system of satellites and ground stations that provide GPS signal corrections for errors caused by ionosphere disturbances, timing, and satellite orbit errors. The Federal Aviation Administration (FAA) and the Department of Transportation (DOT) are developing the WAAS program for use in precision flight approaches. The WAAS specification requires a position accuracy of at least 7.6 meters for both lateral and vertical measurements, 95 percent of the time.
