What does the Wide Area Augmentation System (WAAS) primarily correct?

The Wide Area Augmentation System (WAAS) primarily corrects satellite errors. It enhances the accuracy, integrity, and availability of the Global Positioning System (GPS) by using a network of ground-based reference stations that collect GPS signals. These stations calculate the difference between the GPS signals received and the known positions. This information is then used to correct any errors in the GPS signals caused by various factors, such as atmospheric conditions or satellite positioning inaccuracies.

By disseminating these corrections through geostationary satellites, WAAS improves the precision of GPS positioning in navigation systems used by aircraft, which is vital for safe operations, particularly in approaches and landings. The focus on satellite errors is crucial because even small inaccuracies in satellite positioning can lead to significant errors in navigation, especially in aviation where precision is paramount.