The performance of Global Navigation Satellite Systems (GNSSs) can be improved by regional Satellite-based Augmentation Systems (SBAS), such as the European Geostationary Navigation Overlay Service (EGNOS). SBAS improves the accuracy and reliability of GNSS information by correcting signal measurement errors & by providing information about the accuracy, integrity, continuity và availability of its signals.
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SBAS uses GNSS measurements taken by accurately located reference stations deployed across an entire continent. All measured GNSS errors are transferred lớn a central computing centre, where differential corrections và integrity messages are calculated. These calculations are then broadcast over the covered area using geostationary satellites that serve as an augmentation, or overlay, khổng lồ the original GNSS message.
Several countries have implemented their own Satellite-based Augmentation System. For example, in Europe EGNOS covers the majority of the European Union (EU), along with some neighbouring countries and regions. Other national SBASs include:USA: Wide Area Augmentation System (WAAS)Japan: Michibiki Satellite Augmentation System (MSAS) India: GPS-aided GEO-Augmented Navigation (GAGAN) China: BeiDou SBAS (BDSBAS) (in development)South Korea: Korea Augmentation Satellite System (KASS) (in development) Russia: System for Differential Corrections & Monitoring (SDCM) (in development)ASECNA: SBAS for Africa & Indian Ocean (A-SBAS) (in development)Australia và New Zealand: Southern Positioning Augmentation Network (SPAN) (in development)
All of these systems comply with a common global standard and are therefore:Compatible: they bởi not interfere with each other;Interoperable: a user with a standard receiver can benefit from the same màn chơi of service & performance, regardless of what coverage area they are located in.
SBAS in use
SBAS is essential for applications where accuracy và integrity are critical. In particular, SBAS is indispensable in situations where people’s lives are at stake or where a size of legal or commercial guarantee is required and GNSS is being used. For example, in the aviation sector GPS does not satisfy the strict operational requirements set by the International Civil Aviation Organisation (ICAO) for use in such critical flight stages as final approaches. However, with the addition of SBAS, ICAO standards are satisfied.
Beyond the aviation sector, SBAS improves & extends the scope of such GNSS applications as precision farming, on-road vehicle fleet management và geodesy – lớn name only a few.