GPS қабылдағыштарының дәлдігін арттыратын жүйе

System that enhances the accuracy of GPS receivers

The European Geostationary Navigation Overlay Service (EGNOS) is a satellite based augmentation system (SBAS) developed by the European Space Agency and EUROCONTROL on behalf of the European Commission. Currently, it supplements the GPS by reporting on the reliability and accuracy of their positioning data and sending out corrections. The system will supplement Galileo in a future version. EGNOS consists of 40 Ranging Integrity Monitoring Stations, 2 Mission Control Centres, 6 Navigation Land Earth Stations, the EGNOS Wide Area Network (EWAN), and 3 geostationary satellites. Ground stations determine the accuracy of the satellite navigation systems data and transfer it to the geostationary satellites; users may freely obtain this data from those satellites using an EGNOS enabled receiver, or over the Internet. One main use of the system is in aviation. According to specifications, horizontal position accuracy when using EGNOS provided corrections should be better than seven metres. In practice, the horizontal position accuracy is at the metre level. Similar service is provided in North America by the Wide Area Augmentation System (WAAS), in Russia by the System for Differential Corrections and Monitoring (SDCM), and in Asia, by Japan's Multi functional Satellite Augmentation System (MSAS) and India's GPS aided GEO augmented navigation (GAGAN). Galileo and EGNOS budget for the 2021–2027 period is €9 billion

The system started its initial operations in July 2005, with accuracy better than two metres and availability above 99%. As of July 2005, EGNOS has been broadcasting a continuous signal, and at the end of July 2005, the system was again used to track cyclists in the Tour de France road race. In 2009, the European Commission announced it had signed a contract with the company European Satellite Services Provider to run EGNOS. The official start of operations was announced by the European Commission on 1 October 2009. The system was certified for use in safety of life applications in March 2011. An EGNOS Data Access Service became available in July 2012. Initial work to extend EGNOS coverage to the Southern Africa region is being done under a project called ESESA EGNOS Service Extension to South Africa. The European Commission is defining the roadmap for the evolution of the EGNOS mission. This roadmap should cope with legacy and new missions:
2011–2030: En route / NPA / APV1 / LPV200 service based on augmentation of GPS L1 only. The Safety of Life (SoL) will be guaranteed up to 2030 in compliance with ICAO SBAS SARPS. 2020+: It is planned that EGNOS will experiment with a major evolution, EGNOS V3, including the fulfilment of the SBAS L1/L5 standard, expansion to dual frequency, and evolution toward a multi constellation concept. In 2021, following Brexit, the United Kingdom withdrew regulatory approval for EGNOS, and aircraft pilots were no longer permitted to use the system.

Open Service (OS): It improves positioning accuracy by correcting error sources affecting GNSS signals intended for a wide range of applications in various domains. The corrections transmitted by EGNOS help mitigate the ranging error sources related to satellite clocks, satellite position and ionospheric effects. EGNOS can also detect distortions affecting the signals transmitted by GNSS and prevent users from tracking unhealthy or misleading signals that could lead to inaccurate positioning. The service is available free of charge in Europe to any user equipped with an appropriate GPS/SBAS compatible receiver for which no specific receiver certification is required. It has been available since 1 October 2009. Safety of Life (SoL) Service: The main objective of the EGNOS SoL service is to support civil aviation operations down to Localizer Performance with Vertical Guidance (LPV) minima. However, the EGNOS SoL service might also be used in a wide range of other application domains (e. g. maritime, rail, road ) in the future. This service provides the most stringent level of signal in space performance to all Safety of Life user communities. The EGNOS system has been designed so that the EGNOS Signal In Space (SIS) is compliant with the ICAO SARPs for SBAS. It has been available since 2 March 2011. EGNOS Data Access Service (EDAS): EDAS is the terrestrial data service and offers ground based access to EGNOS data in real time and also in a historical FTP archive to authorised users (e. g. added value application providers). EDAS is the single point of access for the data collected and generated by the EGNOS ground infrastructure distributed over Europe and North Africa, it is aimed at users who require enhanced performance for commercial and professional use. It has been available since 26 July 2012.