EGNOS Satellite Based Augmentation System

The European Geostationary Navigation Overlay Service (EGNOS) is a satellite-based augmentation system (SBAS) developed by the European Space Agency (ESA), the European Commission (EC), and EUROCONTROL. It supplements the primary satellite navigation systems (like GPS and Galileo) by providing corrections to improve the accuracy of the information from these systems. EGNOS uses geostationary satellites and a network of ground stations to receive, correct, and re-transmit signals broadcast by primary GNSS satellites. The corrections are related to the ionospheric disturbances, timing, and satellite orbit errors of the GNSS signals. The EGNOS system is used in aviation, maritime, and land-based applications where precision is crucial. It provides three services: the Open Service (OS), the Safety of Life (SoL) service, and the EGNOS Data Access Service (EDAS). The OS is free to use and provides positioning and timing information, the SoL service provides integrity information about the reliability of the GNSS signals, and the EDAS provides access to EGNOS data in real-time and in a user-friendly format.