The EPN (or EUREF Permanent Network) is a voluntary organization of several European agencies and universities that pool resources and permanent GNSS station data to generate precise GNSS products. The EPN has been created under the umbrella of the International Association Geodesy and more precisely by its sub-commission EUREF.
The European Terrestrial Reference System 89 (ETRS89) is used as the standard precise GPS coordinate system throughout Europe. Supported by EuroGeographics and endorsed by the EU, this reference system forms the backbone for all geographic and geodynamic projects on the European territory both on a national as on an international level.