NOAA will lead an international effort to pinpoint the locations of more than 40 global positioning satellites in Earth orbit, which is vital to ensuring the accuracy of GPS data that millions worldwide rely upon every day for safe navigation and commerce. NOAA personnel will compile and analyze satellite orbit data from 10 analysis centers worldwide to ensure the accuracy of GPS information. For the next four years NOAA’s National Geodetic Survey will serve as the Analysis Center Coordinator for the International Global Navigation Satellite Systems Service, a voluntary federation of more than 200 organizations that provide continuous global satellite-tracking data.