What does WAAS stand for?

WAAS stands for Wide Area Augmentation System. This is an integral part of the GPS system in the United States designed to improve the accuracy, integrity, and availability of GPS signals. It accomplishes this by using a network of ground-based reference stations that monitor the GPS satellite signals. The data collected from these stations is then processed and used to generate correction signals that are transmitted to satellites, which relay them back to GPS receivers.

This system is crucial for aviation and other applications where precision navigation is necessary, as it can improve GPS accuracy from about 10 meters to within 1-2 meters. Understanding the function and purpose of WAAS is important for pilots and navigators, as it enhances the reliability of GNSS in flight operations, particularly during approaches and landings.

The other options provided do not accurately describe WAAS and do not relate to the specific technology and function it represents in navigation systems.