The full form of WAAS is Wide Area Augmentation System.
WAAS is a Satellite-Based Augmentation System (SBAS) developed by the Federal Aviation Administration (FAA) to improve the accuracy, integrity, and availability of GPS signals for civil aviation. It essentially enhances the GPS signal, making it more reliable for critical applications like landing aircraft. By using a network of ground reference stations that monitor GPS satellites, WAAS can correct errors and provide a more precise position to GPS receivers equipped to receive WAAS signals. This improved accuracy translates to safer and more efficient navigation, especially during low-visibility conditions.
In essence, WAAS works by:
- Monitoring GPS Satellites: A network of ground reference stations across North America tracks GPS satellite signals.
- Calculating Corrections: These stations calculate corrections for errors in GPS signals, such as those caused by atmospheric interference or satellite clock drift.
- Uplinking Corrections: The corrections are then uplinked to geostationary satellites (communications satellites).
- Broadcasting to Receivers: These geostationary satellites broadcast the correction signals to WAAS-enabled GPS receivers.
- Improving Accuracy: The receivers use the correction data to improve the accuracy of their GPS position, often down to within a few meters.
WAAS primarily benefits aviation, allowing for more precise instrument approaches, especially in areas where ground-based navigation aids are limited or unavailable. However, its benefits extend to other applications requiring improved GPS accuracy, such as precision agriculture, surveying, and mapping.
