EGNOS

The purpose of the European Geostationary Navigation Overlay Service, EGNOS, is to monitor the real-time performance of US GPS satellites, then generate a correction message, containing information on the reliability and accuracy of their positioning data, which are then broadcast via EGNOS’s geostationary satellites to all suitably equipped satnav receivers. EGNOS consists of three geostationary satellites and a Europe-wide ground segment composed of two master control stations, six uplink stations and a network of 40 monitoring stations, all connected and communicating in real time.