EUREF is the Reference Frame Sub-commission for Europe of the IAG (International Association of Geodesy), a component of the Regional Reference Frames Sub-commission, integrated in Commission 1-Reference Frames. The long-term objective of EUREF, as defined in its Terms of Reference,“is the definition, realization and maintenance of the European Reference Systems, in close cooperation with the pertinent IAG components (Services, Commissions, and Inter-Commission projects) as well as EuroGeographics”.

The results and recommendations proceeding from EUREF support the use of the European Reference Systems in all scientific and practical activities related to precise geo-referencing and navigation, Earth sciences research and multidisciplinary applications. EUREF makes use of the most accurate and reliable terrestrial and space-borne techniques available, and develops the necessary scientific background and methodology.
Its activities are focused on a continuous innovation and on the changing user needs, as well as on the maintenance of an active network of people and organizations, and may be summarized as follows:

• to maintain the ETRS89 (European Terrestrial Reference System) and the EVRS (European Vertical Reference System) and upgrade the respective realizations;
• to refine the EUREF Permanent Network (EPN) in close cooperation with the IGS;
• to improve the Unified European Levelling Network (UELN);
• to contribute to the IAG Project GGOS (Global Geodetic Observing System) using the installed infrastructures managed by the EUREF members.

These activities are reported and discussed at the EUREF Symposia, an event that occurs every year since 1990, with an attendance of about 100 participants coming from more than 30 countries in Europe and other continents, representing universities, research centres and the NMCA (National Mapping and Cadastre Agencies). It's an open forum, and may be attended by any person interested in the work of the Sub-Commission.

The organization of the EUREF Symposia has been and will be supported by EuroGeographics, the consortium of the European NMCA, reflecting the importance of the EUREF work for practical purposes. This involvement is consolidated by a formal liaison between EUREF and EuroGeographics.

For the year 2009 we have the kind invitation from the Italian Istituto Geografico Militare (IGM), to hold the 2009 Symposium in Florence, from 27 to 30 May.

The scientific programme will cover the following preliminary topics:

• Activities of the TWG
• New Developments in GNSS Networks
• Modelling the Earth with GNSS
• Mitigation of GNSS Error Sources
• Height, Gravity, Geoid, and Combination of Techniques
• Improvements and Densifications of the ETRS89
• National Reports

Presentations (oral and poster) on these and related topics are welcome, as well as National Reports covering the activities carried out at national level in the context of EUREF. We invite anyone to make his/her contribution, and we are sure that the Symposium that will take place in Florence, will be a successful one.

Johannes Ihde, EUREF Chair
Helmut Hornik, EUREF Secretary