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.
