The IAG Subcommission 1.3.a for Europe EUREF started in 1994 with its activities for development and establishment of European height systems. Several projects were initiated. The work base on an excellent cooperation between, National Mapping Agencies (Comité Européen des Responsables de la Cartographie Officielle – now EuroGeographics) and the Technical Working Group EUREF In accordance with the Resolution No. 3 of the Symposium 1994 in Warsaw, the objective of the United European leveling Network (UELN) project is to establish an unified vertical datum for Europe at the one-decimeter level with simultaneous enlargement of UELN as far as possible to the Eastern European countries.
The results of the adjustment with status of end 1998 were handed over to each participating country under the nameUELN95/98. One year later at the EUREF symposium 2000 in Tromsø a first definition of the European Vertical Reference System (EVRS) was adopted. The realization on the base of the UELN95/98 solution got the nameEVRF2000.
The European Vertical Reference Network (EUVN) was prepared in parallel to the UELN. It is an integrated network of GNSS, levelling and tide gauge observations as a static height reference. On the basis of UELN and EUVN it was possible to derive relations between the UELN datum Normaal Amsterdams Peil and the European national height datums.
In the meantime the importance of harmonization of the vertical reference of spatial coordinates increased on the one hand and the extension, density and topicality of the available data were improved on the other hand. Half of the participating countries provided new national leveling data to the UELN data centre after the release of the last solution EVRF2000. Therefore, a new realization of the EVRS was computed and published under the name European Vertical Reference Frame 2007 Read More
