European Geodetic Reference Systems


In 1987, the IAG and CERCO decided to develop a new European Geodetic Reference Frame based on GPS. This reference should be a precise continent-wide modern reference near to the WGS84 and usable for multinational Digital Cartographic Datasets, no longer derived from multiple national datums across Europe. It should unify national reference systems for surveying, mapping, GIS and navigation in Europe.
As in the late eighties the International Terrestrial Reference System (ITRS) was the most precise global reference system available, EUREF decided to base its reference on the ITRS which is maintained by the International Earth Rotation and Reference Systems Service (IERS). However, in the global ITRS, plate tectonics cause the coordinates of European stations to slowly change in the order of about 2.5 cm/year. Therefore, in 1990 at it symposium in Firenze, Italy, EUREF designed the European Terrestrial Reference System 89 (ETRS89) in such a way that it would be based on the ITRS except that it is tied to the stable part of Europe, so that the relations between European stations are kept fixed. Coordinates in ETRS89 are expressed as either three dimensional (X, Y, Z) Cartesian coordinates or as three dimensional ellipsoidal coordinates (Φ, λ and H, Ellipsoidal height), based on the GRS80 ellipsoid.
The acceptance of ETRS89 by several communities (civil aviation, industry, national and regional agencies) as the backbone for geo-referencing in Europe is a continuous process. EuroControl (European Agency for Safely of Air navigation) uses ETRS89 since a long time in its technical specifications and there is a recommendation by the European Commission to adopt ETRS89 as the geodetic datum for geo-referenced information and to promote the use of ETRS89 within its member states.
EUREF and EuroGeographics conducted in 2005 a survey among 41 NMCA in the European countries. From the 28 answers, 78% of the NMCA already adopted officially the ETRS89 and 18% of them will adopt it in the near future. In the majority of the countries the usage of the ETRS89 is not mandatory in all situations, due to the existence of national reference systems and the need to have a transition period until the ETRS89 can be fully adopted.

More details:
EVRS – European Vertical Reference System

The web project EVRS (European Vertical Reference System) includes, as described in detail in the chapter dealing with the European height reference system, information about this coordinate reference system, their realizations EVRF2000 and EVRF2007 and related projects as, e.g. realization of the EUVN (European Vertical Reference Network) and EUVN_DA (EUVN Densification Action).
CRS-EU – Information system for European Coordinate Reference Systems

The information system CRS_EU containing the description of pan-European and national coordinate reference systems as well as their relations with each other. It is based on information of the National Mapping Agencies of European countries, is edited in accordance with an ISO standard and verified by test computations.

The information offered includes:
– description (reference system, coordinate system or map projection) of the pan-European coordinate reference systems ETRS89, EVRF2000 and EVRF2007 and the coordinate reference systems of most European countries

– parameters for the transformation of the national coordinate reference systems into the pan-European coordinate reference systems for position and height.

– verification coordinates for check transformation and online-transformation of single points for position from national coordinate reference systems to pan-European coordinate reference systems ETRS89 for test and verification purposes

This way, the requirements imposed by the users of geoinformation and by other users of geodetic-cartographic information shall be met in a better way regarding such issues as geodetic referencing.
EUREF Densification Campaigns

ECGN – European Combined Geodetic Network

In order to be able to refer to an integrated European reference network for spatial reference purposes, the creation of a ECGN is already under way. This network combines measurements of the Global Navigation Satellite Systems (GNSS) and other space techniques with gravity and levelling measurements. Sea level and other measurements will also be integrated into this network.

The web pages of the ECGN – European Combined Geodetic Network – serve the provision of information and the project management. They contain calls for participation in this project, station data, guidelines for the measurement, and other details.

Technical Working Group (TWG)

The EUREF TWG was created at the EUREF symposium in Berne, 1992.

The TWG meets twice to three times a year to manage current activities. One of these activities is the validation of GPS campaigns under the established guidelines, for approval by the plenary.

The minutes of the meetings are published together with the symposia proceedings.

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General information

The EUREF TWG (Technical Working Group) was created at the EUREF symposium in Berne, 1992.

The TWG is responsible, in general, for the control of EUREF activities and policy, and has the following specific tasks:
to coodinate and develop the EPN (EUREF Permanent Network);
to evaluate and classify results of GNSS campaigns presented to the TWG for acceptance as EUREF densification or extension;
to organize and coordinate European-wide geodetic observation campaigns for the improvement of the European reference frame;
to coordinate the actions for the realisation of a European Height System and the integration of the geo-spatial and vertical components of the European Reference Frame;
to identify the relevant actions for the continuation and development of EUREF, with respect to innovation and the changing user needs;
to set up the working groups to run the projects defined by the plenary;
to prepare the recomendations for the EUREF plenary.

The TWG meets at least twice a year, preferably three times a year.

The TWG is constituted by members elected by the plenary, ex-officio members and members in charge of specific tasks.

The TWG Chair, elected among and by its members, coordinates the TWG. The term is 4 years, in a maximum of 2 terms.

The number of members elected by the plenary is defined by the TWG Chair and must be in agreement with the tasks committed to the TWG. The recommended term is 4 years.

The ex-officio members are the EUREF Chair and Secretary.

Members in charge of a specific task, in a limited number, also compose the TWG. The TWG Chair appoints these members. The term is established according to the tasks commited.

The TWG Chair may invite persons to attend the meetings, to assist in the discussion of specific subjects or to present relevant items to EUREF. These persons have no voting rights.

The WG (Working Group) are established within the TWG and appoved in a Plenary’s resolution. The TWG Chair proposes the leadership of the WG. The leader of a WG must be a member of the TWG.


EUREF is the IAG Reference Frame Sub-Commission for Europe, integrated in the Sub-Commission 1.3, Regional Reference Frames, under Commission 1 – Reference Frames, following the implementation of the new IAG structure at the IUGG (International Union of Geodesy and Geophysics) General Assembly held in Sapporo, 2003.

The Sub-Commission EUREF was founded in 1987 at the IUGG General Assembly held in Vancouver.

EUREF deals with the definition, realization and maintenance of the European Reference Frame – the geodetic infrastructure for multinational projects requiring precise geo-referencing (e.g. three-dimensional and time dependent positioning, geodynamics, precise navigation, geo-information) – in close cooperation with the IAG components (Services, Commissions, and Inter-commision projects) and EuroGeographics, the consortium of the National Mapping Agencies (NMA) in Europe.

Mission & Objectives

EUREF, the “Reference Frame Sub-Commission for Europe” is part of the Sub-Commission 1.3, Regional Reference Frames, under Commission 1 of the IAG. The activities and tasks of EUREF are to:

develop, in close cooperation with the IGS (International GNSS Service), the EUREF Permanent Network (EPN) for the maintenance of the European Reference Frame, as contribution to the ITRF and as infrastructure to support other relevant projects, namely the European initiatives related to Galileo;
improve the Unified European Leveling Network (UELN) by extending it to all European countries, taking into account the perspective of a geokinematic computation;
implement the necessary projects for the long-term maintenance of the ETRS89 (European Terrestrial Reference System) and the EVRS (European Vertical Reference System), as well as for the improvement of the coherence between both systems, and this in close cooperation with other IAG components;
promote the adoption of the reference systems defined by EUREF (ETRS89 and EVRS) in the European countries and European-wide organizations involved in geo-referencing activities.

Terms of Reference (ToR)

The complete Terms of Reference (ToR) for EUREF have been updated at the EUREF 2008 Symposium held in Brussels.

EUREF Partners

EUREF established partnerships through a Memorandum of Understanding with the following organizations:


is the umbrella organization of the European National Mapping and Cartographic Agencies. The Memorandum of Understanding between EUREF and EuroGeographics is a more intensive continuation of the hitherto cooperation for common interests between both organizations. It guarantees on one hand that the developments made by EUREF are absorbed and implemented by the NMCA; and on the other hand, brings to EUREF the NMCA concerns and problems on geodetic issues that must be solved in a European and global perspective. The cooperative activities will be developed in the following areas: the European Spatial Data Infrastructure (INSPIRE), Global Monitoring for Environment & Security (GMES), Galileo and its applications related to geo-information, and sharing of best practice within and between the participants’ members.
More details: Memorandum of Understanding


is a network of European national meteorological services, facilitating committing inter-European collaboration within meteorology. The goals of the Memorandum of Understanding between EUREF and EUMETNET are to increase synergies and collaborations between the geodetic and meteorological communities and to facilitate the data exchange between the two parties. On one hand, E-GVAP, a program running under the aegis of EUMETNET, aims at establishing a European observing system for delivering near real-time GNSS-based tropospheric zenith path delay (ZPD) estimates for operational numerical weather prediction (NWP). For that, meteorologists need continued access to GNSS raw data and products. On the other hand, EUREF needs access to meteorological observations over all Europe In order to improve its GNSS data processing and to validate its GNSS-derived products from the EUREF Permanent Network (EPN).
More details: Memorandum of Understanding


is a scientific Consortium of Research Institutions committed to a coordinated programme of measurements, technical developments and for international access to monitoring geodetic and geodynamic processes for a long period of time in Central Europe. The objective of this Memorandum of Understanding is, in general, to create the conditions to facilitate the data exchange and to promote the increase in the co-operation between the two parties, and in particular, to facilitate the densification of the European GNSS network for reference frame definition and geokinematical applications, and to support the ECGN (European Combined Geodetic Network) project. It is expected that a closer co-operation between EUREF and CEGRN will increase the level of support to the IAG Dense Velocity Field Project, and the availability of a combined solution with respect to a denser network.
More details: Memorandum of Understanding



The International GNSS Service (IGS), formerly the International GPS Service, is a voluntary federation of more than 200 worldwide agencies that pool resources and permanent GPS & GLONASS station data to generate precise GPS & GLONASS products.
The EUREF Permanent Network is considered as the European regonial densification of the IGS. In a spirit of cross-fertilization, EUREF members are participating to the IGS real-time Pilot Project, the IGS GNSS Working Group, the IGS antenna calibration Working Group and the IGS Infrastructure Committee. In addition, IGS standards are used for the routine EPN operations.

IAG WG on “Regional Dense Velocity Fields”

The IAG Working Group on ‘Regional Dense Velocity Fields’ is part of IAG Sub-Commission 1.3 ‘Regional Reference Frames’ which is embedded in IAG Commission 1 on Reference Frames.In a collaborative effort with the regional sub-commissions within IAG sub-commission 1.3 (such as EUREF), the IAG Working Group on ‘Regional Dense Velocity Fields’ aims at creating a dense global velocity field. For that purpose, EUREF collects GNSS-based velocity solutions from all over Europe and combines them into one single solution which is submitted to the Working Group. The Working Group then combines all regional and global velocity solutions to obtain a global dense velocity field.

ICG (International Committee on Global Navigation Satellite Systems)

The International Committee on Global Navigation Satellite Systems (ICG) had been established on a voluntary basis as an informal body to promote cooperation on matters of interest related to civil satellite-based positioning, navigation, timing and value-added services, as well as the compatibility and interoperability of global navigation satellite systems, while increasing their use to support sustainable development, particularly in developing countries. Members of ICG are providers of Global Navigation Satellite Systems (GNSS). EUREF is associated member of ICG. Goals of the annual meetings are reviewing and discussing developments in GNSS and to allow ICG members, associate members and observers to consider matters of interest. ICG also addressed GNSS technology in the era of multi-systems receivers and the impact of GNSS interoperability on timing and other user applications. Representatives from industry, academia and Governments shared views on GNSS compatibility and interoperability.

FIG Commission 5 – Positioning and Measurement

FIG was founded in 1878 in Paris and was known as the Fèdèration Internationale des Gèometres. This has become anglicized to the International Federation of Surveyors. It is an UN-recognized non-government organization (NGO), representing more than 100 countries throughout the world, and its aim is to ensure that the disciplines of surveying and all who practise them meet the needs of the markets and communities that they serve.

FIG is the premier international organization representing the interests of surveyors worldwide. It is a federation of the national member associations and covers the whole rage of professional fields within the global surveying community. It provides an international forum for discussion and development aiming to promote professional practice and standards.

Ten commissions lead FIG’s technical work. Each member association appoints a delegate to each of the commissions. Detailed information on the work of the commissions, their work plans, working groups, seminars, newsletters and publications can be found at

FIG Commission 5 (Positioning and Measurement) has the strongest links with IAG. A MoU between FIG and IAG was signed in 2001 and Commission 5 has the lead within FIG on the collaboration with IAG.

FIG Commission 5 deals with the science of measurement (instrumentation, methodology and guidelines) and the acquisition of accurate and reliable survey data related to the position, size and shape of natural and artificial features of the earth and its environment and including variation with time. The work plan of the commission covers the development, use and integration of technologies for positioning and measurement and the associated standardisation, best practice and fundamental reference frame issues. Many of the issues are global in nature and Commission 5, working with like-minded Sister Associations as IAG, is well placed to deal with them. FIG Council has also asked the Commissions to cooperate with United Nations Agencies to address global problems such as sustainable development and humanitarian needs. The disciplines covered by Commission 5 are at the heart of delivering solutions for the spatial aspects of these important global problems. Specific activities aimed at developing countries include examination of Low Cost Surveying Technologies, assistance with implementation of modern Geodetic Reference Frames and associated infrastructure and contribution to appropriate Continuing Professional Development programs.

FIG Commission 5 has during the last 10 years focused on facilitating the exchanging of information and knowledge regarding national GNSS CORS and the services connected to them, GNSS modernisation, new positioning and measurement techniques, as well as the development of regional reference frames. FIG has assisted and supported the work run by IAG on projects such as AFREF and more recently APREF.


WEGENER (Working Group of European Geoscientists for the Establishment of Networks for Earth science Research) is a IAG Inter commission project with Commission 1 and Commission 3. Commission 1 is responsible for regional and global reference frames, for the coordination of space techniques and for satellite dynamics. WEGENER contributes significantly to each one of these areas and, in particular, to regional and global reference frames by making available, in its study area, quality-tested regional data sets acquired with different space and terrestrial techniques, as well as relevant quality-tested solutions. Commission 3 is responsible for earth rotation and geodynamics. WEGENER provides its main contribution in the field of geodynamics by studying, regionally, both short and long-term crustal motions.