Positions & Velocities
The most accurate and up-to-date EPN station positions and velocities are derived from a multi-year combination of the EPN daily combined SINEX files. This multi-year solution is used for the realisation of the regional densification of the ITRFyy/IGSyy between two releases and also for the maintenance of the ETRS89. The multi-year combination comprises EPN-repro2 daily SINEX files from GPSweek 834 up to GPSweek 1772 and routine daily EPN combined SINEX files from GPSweek 1772 up to the most recent solutions. The multi-year solution is updated each 15 weeks in order to provide up-to-date coordinates and velocities.
Based on the EPN multi-year position and velocity solution and its associated residual position time series, the EPN stations are categorized taking into account the station quality and the length of the available observation time span:
- Class A: station positions have a 1 cm accuracy at all epochs of the time span of the used observations
- Class B: station positions have a 1 cm accuracy at the epoch of minimal variance. Stations are in Class B because of a short time frame of SINEX availability or a higher noise level (including the seasonal variability) of the position time series.
Remark: The categorization of the EPN stations is currently under revision. It will be improved in the future realization. Don't hesitate to contact the EPN Reference Frame Coordinator (J. Legrand) for any questions or comments.
Only Class A stations are suitable as reference stations for the densification of the ETRS89. The associated files can be downloaded from the EPN Central Bureau; the most recent realization is available through the links:
In the ITRS (IGS14 realization) :
- EPN_A_IGS14.SSC, table with station positions (at epoch 2010.0) and velocities
- EPN_A_IGS14.SNX.Z, solution in SINEX format
- EPN_A_ETRF2000.SSC, table with station positions (at epoch 2010.0) and velocities
- EPN_A_ETRF2000.SNX.Z, solution in SINEX format
- EPN_A_ETRF2014.SSC, table with station positions (at epoch 2010.0) and velocities
- EPN_A_ETRF2014.SNX.Z, solution in SINEX format
More details about the usage of the Class A stations for EUREF densifications are available from "Guidelines for EUREF Densifications" by Bruyninx et al.
For Class B stations, EUREF provides only position estimates (EPN_B_IGS14.SSC, EPN_B_ETRF2000.SSC, EPN_B_ETRF2014.SSC) at the epoch of minimal variance. The velocity estimates of the Class B stations are not released because of their limited accuracy (caused by e.g. the short observation period of the station, or lower data quality). However, Class B velocities are available upon request ftom the EPN Reference Frame Coordinator.
Since the release C1950, the EPN cumulative solution is maintained by the EPN Reference Frame Coordinator (J. Legrand).
Remark: Compared to previous version this solution has some differences and new features:
C1934 New Reference frame IGb08 IGS14 Associated atx calibration file epn_08.atx epn_08.atx converted to epn_14.atx + epn_14.atx Input SINEXs weekly daily Reference frame epoch 2005.0 2010.0 Earthquake modelling for ITRF stations Piece-wise linear Post-seismic deformation modeled for ANKR00TUR, BUCU00ROU, ISTA00TUR, REYK00ISL, TUBI00TUR Discontinuity list C1934 Update Software CATREF CATREF Align to IGxxx with translation, rotation, scale translation, rotation, scale
Description and additional information about the EPN multi-year solution :
- An updated version of the description is currently under preparation. A preliminary version of the current solution has been presented at the EUREF AC Workshop held in Brussels, the October 25-26, 2017 (Presentation). Description for the previous solution is available here
- Map of the multi-year EPN positions and velocities.
- EPN station discontinuities, be careful for some stations (due to different period of observations) the harmonization with the IGS/ITRF discontinuity table was not possible.
- List of rejected outliers. Format has changed in order to take into account daily files.
- Residual position time series.
- Miscellanous plots