The National Oceanic and Atmospheric Administration reports it has brought 43 GPS tracking stations online, including 13 sites that will feed the WAAS (Wide Area Augmentation System) network. Four of the new WAAS sites are located in Alaska, four in Canada, and five in Mexico. The NOAA’s release explains:
WAAS provides differential GPS correctors for safe airline navigation across North America. These correctors help more precisely determine a position and enable pilots to determine the three-dimensional location of their aircraft with an accuracy of a few meters.