Sessions

Opening Session

Chairperson: Alessandro Caporali

Session 1: Activities of the TWG

Chairperson: Johannes Ihde, Carine Bruyninx

This session is dedicated to the activities of the EUREF Technical Working Group

Session 2: New developments in GNSS networks (EPN, other networks, real time, GLONASS/Galileo)

Chairperson: Heinz Habrich

This session shows new developments in GNSS networks in the broadest sense. The presentations have a close relation to the EPN, but also other regional and global networks will be addressed. Real-time applications became a challenging tool during the last years and have been pushed by increased internet connectivity. Technologies for streaming observation data, analysis of data and providing the products in real-time have been developed and the accuracy of geodetic parameters as determined through such techniques is going to be improved rapidly. Experiences in operating a network of stations that make their data available in real-time will be discussed. The deployment of more than eighteen GLONASS satellites and the first two Galileo test satellites in space build together with GPS satellites a real GNSS constellation. The extended satellite constellation asks station operators to install combined receivers that are capable to track GPS/GLONASS and in future Galileo. Furthermore new satellite signals such as L2C are now broadcasted by newly launched satellites or such as L5 are going to be transmitted after next satellite launches. The potential of new satellite constellations and frequencies will be shown, as well as today's realisation in GNSS networks.

Session 3: Modelling the Earth with GNSS

Chairperson: Jan Dousa

Latest improvements in modelling the lower and upper atmosphere proved that GNSS could serve as a valuable and efficient tool for sensing the Earth atmosphere for various purposes - numerical weather prediction, climate study, space weather monitoring etc. With advanced technology, new analysis models and efficient techniques, the monitoring of the solid Earth deformations or variations in the liquid Earth provides further expectation on GNSS in future too. The session solicits contributions with new achievements in modelling/monitoring the solid and liquid Earth and its atmosphere with GNSS, contributions demonstrating new approaches and products, their validation and exploitation.

Session 4: Mitigation of GNSS error sources

Chairperson: Elmar Brockmann

Site effects and propagation effects still control the accuracy with which GNSS phase tracking data can be modelled. Site effects address the displacements of the physical position of the GNSS antenna, and therefore include monumentation, antenna calibration, tidal displacements and surface mass loading. Propagation effects address effects due to the troposphere, ionosphere or multipath. The influence of these effects on GNSS-derived products (such as station coordinates, station velocities, zenith total delay estimates for numerical weather prediction, troposphere horizontal gradients, etc.) is an area of advanced research. Some groups in Europe started with re-processing activities in the last years, in order to generate results which are based on an homogeneously set of models. A new special project within EUREF has recently be started in order to coordinate these activities.

The session solicits contributions focussing on the sources of systematic errors that limit the accuracy of GNSS products. We welcome papers with analyses and new ideas on how to calibrate or to prevent such systematic errors, or on techniques to recognize their signature in the data, and possibly minimize them. Also welcome are papers comparing results with results derived from other sources or results stemming from a re-processing.

Session 5: Height, Gravity, Geoid, and Combination of Techniques

Chairperson: Markku Poutanen

Gravity-related heights, i.e., heights based on potential differences remain fundamental. Definition and realization of the European Vertical Reference System (EVRS) is under way, and many countries are renewing or updating their height systems. Simultaneously, the realization of heights using 3-D coordinates and geoid models is continuously improving, supported by the gravity satellite missions GRACE and GOCE. Gravity methods are increasingly contributing to the maintenance of reference frames. Combining different techniques and data access in a systematized way will be done under the umbrella of the Global Geodetic Observation System GGOS and regionally, under the European Combined Geodetic Network ECGN.

We solicit papers on the definition and realization of height systems at the national, European and global level, on gravity-field modelling and geoid computations, on the use of gravity and multiple techniques in the maintenance of the reference frame. Especially welcome are papers on the contribution of EUREF to the ECGN or GGOS.

Session 6: Improvements and densification of ETRF89

Chairperson: Joao Torres

The European Terrestrial Reference Frame (ETRS89) is currently the basis for geo-referencing in most of the European continent, and will play a key role in INSPIRE.

For this session the presentations will cover the following aspects:

• scientific and technical developments related to the improvement of ETRS89;
• presentation of GNSS campaigns as extensions and upgrades of the ETRF;
• practical developments for the adoption of ETRS89 at sub-regional and national level;
• developments and new implementations of the European Coordinate Reference Systems (CRS) Information and Service System.

Session 7: National Reports

Chairperson: Jan Krynski

National surveying and mapping authorities of European countries report in this session on all branches of their activities, from geodetic surveying to the establishment of geometric reference systems and positioning, to gravimetric and height related tasks, and to outstanding developments in geo-information systems. The implementation of EUREF results on national level is of particular interest. Due to the limited time, which is typically only a few minutes for each country, the reports must focus on new developments since the last report given at a EUREF symposium.

In addition, this year, the EUREF TWG would like to ask the national representatives to specify in the national reports how the official national ETRF coordinates of the permanent stations are maintained. Background of this query is the activity within projects of INSPIRE and EuroGeographics, where the usage of ETRS89 as the common reference system for data exchange in Europe is a key issue.

Due to the fact that the official national ETRF coordinates are based on different realizations (different ETRF reference frames, different definition times, different campaign-style analyses, etc.), the EUREF TWG likes to perform a survey, how homogeneous the different frames are realized. With the recently published European densification solution of the ITRF2005 (EUREF mail 4142) homogeneous, scientific, coordinates of each permanent station are published on the EPN web pages (e.g. for station XXXX http://www.epncb.oma.be/_trackingnetwork/coordinates/stationcoordinates4onestation.php?station=XXXX ; first table under "A) Positions/velocities published by EUREF (release Dec. 2008)", section ETRF2000). We therefore would like to ask the national representatives to compare these published scientific coordinates of the EPN stations with the national official ETRF coordinates and to report on detected differences, which may also be assigned to problems in the densification solution.

At the symposium we plan to discuss, if the publication of the official national ETRF coordinates for permanent EPN-stations on the EPN and/or CRS-EU web-page (if the representatives of the countries agree) is a gainful extension of the present monitoring of the EPN network. The EUREF TWG is prepared to offer a service to the contributing countries by submitting a feedback, if the EPN-generated scientific coordinates should disagree considerably with the used coordinates in the countries. Results of this query will be presented at the symposium for about 15 countries, which were already asked to provide some feedback.

For more details: E. Brockmann (elmar.brockmann@swisstopo.ch)

Closing Session

Chairperson: to be determined