(From the Garmin site)
WAAS consists of approximately 25 ground reference stations positioned across the United States that monitor GPS satellite data. Two master stations, located on either coast, collect data from the reference stations and create a GPS correction message. This correction accounts for GPS satellite orbit and clock drift plus signal delays caused by the atmosphere and ionosphere. The corrected differential message is then broadcast through one of two geostationary satellites, or satellites with a fixed position over the equator. The information is compatible with the basic GPS signal structure, which means any WAAS-enabled GPS receiver can read the signal.
Quote:
Originally posted by lincomatic
WAAS support definitely improves accuracy, but if i remember correctly, there are currently only 2 satellites and it's hard to get a clear sky view to them at all times.
as far as stumbling is concerned, the position of the AP is just an estimate based on the signal strength trajectory, so it adds so much error that talking about GPS error relative to stumbling is moot.
just my 2cents. [/b]
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