Which system is used primarily in North America to improve GPS capabilities?

The Wide Area Augmentation System (WAAS) is specifically designed to enhance the accuracy, integrity, and availability of GPS signals in North America. It accomplishes this by using a network of ground-based reference stations that monitor GPS satellite signals. Any discrepancies in GPS signals are detected, and correction information is sent to geostationary satellites, which then broadcast the corrections to users' receivers. This results in improved positional accuracy, allowing for more reliable navigation and precision approaches, particularly crucial in areas where accuracy is critical for aviation.

The use of WAAS is particularly valuable for aviation, as the system supports precision approaches and can allow for flights to operate in lower visibility conditions by providing tighter accuracy than standard GPS alone. Overall, WAAS not only enhances the functionality of GPS but also provides users with better situational awareness and safety in their operations.