Positions & Velocities
The most accurate and up-to-date EPN station positions and velocities are derived from a multi-year adjustment of the EPN weekly SINEX product. The cumulative 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 adjustment comprises weekly SINEX files from GPSweek 834 up to the most recent solutions involving the EPN_REPRO1 results and the routine weekly EPN product. The multi-year solution is updated each 15 weeks in order to provide up-to-date coordinates and velocities.
Based on the series of the regularly updated EPN multi-year position and velocity solution, the EPN stations are categorized taking the station quality and the length of the available observation time span into account (Kenyeres, 2010):
- 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.
Only Class A stations are suitable as fiducial 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 (IGb08 realization) :
- EPN_A_IGb08.SSC, table with station positions (at epoch 2005.0) and velocities
- EPN_A_IGb08.SNX.Z, solution in SINEX format
- EPN_A_ETRF2000.SSC, table with station positions (at epoch 2005.0) and velocities
- EPN_A_ETRF2000.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_IGb08.SSC, EPN_B_ETRF2000.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 addressed to the EPN Reference Frame Coordinator.
The EPN cumulative solution is maintained by the EPN Reference Frame Coordinator (A. Kenyeres).
Description and additional information about the EPN multi-year solution :
- Map of the multi-year EPN positions and velocities.
- EPN station discontinuities, fully harmonized with the IGS/ITRF discontinuity table.
- List of rejected outliers.
- Residual position time series.
- Miscellanous plots