ORGANISATION > STRUCTURE

EPN management The ETRS89 is maintained thanks to the creation of a European permanent GPS station network, known as the EUREF permanent network (EPN).

EUREF TWG EPN Coordination Group EPN Central Bureau Data Centres Analysis Centres Projects GNSS EPN Stations

This permanent network consists of part of the GNSS permanent tracking stations distributed over almost all European countries. The EPN consists of the following components:

  • Tracking Stations (TS): They set up and operate the permanent GNSS tracking receivers and antennae on suitable geodetic markers.

  • Operational Centres (OC): They perform data validation, conversion of raw data to Receiver Independent Exchange Format (RINEX), data compression, and data upload to a data centre through the Internet. For some stations the OC is identical with the institution responsible for the respective station (i.e., the OC is identical with the TS).

  • Local Data Centres (LDC): They receive the data of all stations of a local network and distribute them to the users (local and EPN). One or more of these stations are part of the EPN network. For many of the local networks the LDC will be identical with their Operational Centre.

  • Local Analysis Centres (LAC): They process a subnetwork of EPN stations and deliver weekly free network solutions to the Combination Centre. All processing is done following specific international guidelines. The subnetworks have been designed in such a way that each station has minimally three analysis centres. Thanks to this redundancy errors can be eliminated without any problems. This solution is available in the SINEX format (Software Independent Exchange format).

  • A Combination Centre (CC): It combines the individual subnetwork solutions into one official EPN solution including all tracking stations. This solution is send to the IGS where it is integrated in the global GNSS network. Once a year a multi-year EUREF solution is sent to the IERS, with as direct result that the EUREF stations become primary ITRS stations.

  • A Central Bureau, which coordinates the activities of the tracking stations, data centres and analysis centres. It distributes standards and guidelines. It maintains the history information of all tracking stations, checks the individual coordinate time series and notifies the EUREF user community when a station does not fulfil the standards or when irregular behaviour is detected through a coordinate variation.