Description & Download
The EUREF reference frame solution provides the most accurate positions and velocities for the EPN GNSS stations. However, due to the transition to the IGS20 reference frame and the absence of an EPN Repro3 solution using IGS20 modelling standards (e.g., epn20.atx), updates to this product have not been possible since February 2023. Its last official version remains therefore in IGb14 and is available here.
While awaiting the EPN Repro3 solution, a temporary hybrid solution has been developed to bridge the gap. This temporary hybrid solution is suitable for monitoring purposes, offering updated station positions in IGS20 starting from November 2022. However, it is not valid for periods before November 2022, when it is based on the epn14.atx antenna model rather than the current epn20.atx.
The hybrid solution is a multi-year position and velocity solution computed with the CATREF software (Altamimi et al., 2007). The positions and velocities are aligned to the IGS20 reference solution under minimal constraints using 14 transformations parameters (translations, rotations, scale and their rates) on a selection of IGS20 reference stations.
- Discontinuities
- During the stacking, position and velocity discontinuities (discontinuity file) are introduced to account for sudden position change or velocity change in the position time series. A new station position and velocity is estimated after each discontinuity and the velocities are usually constrained to be equal before and after a discontinuity.
- Post seismic deformations
- In addition, this solution incorporates the ITRF2020 post-seismic deformation models for 3 stations: ISTA00TUR, REYK00ISL, TUBI00TUR.
- Collocated stations
- Also, except in cases of significant disagreements, the velocities of collocated sites are constrained to be the same.
- Input Files
-
The EPN multi-year solution, is computed using the EPN daily combined SINEX files:
- from GPS week 834 up to GPS week 1772, the daily SINEX from the EPN-repro2 computed using the epn_08.atx calibration file and corrected to be in accordance with the epn_14.atx antenna calibration model.
- between GPS week 1772 and GPS week 1933, the operational daily EPN combined SINEX files computed using the epn_08.atx calibration file and corrected to be in accordance with the epn_14.atx antenna calibration model.
- between GPS week 1934 and GPS week 2133, the operational daily EPN combined SINEX files computed using the epn_14.atx calibration file.
- after GPS week 2134, the operational daily EPN combined SINEX files computed using the epn_20.atx calibration file.
Remark: The most recent EUREF reference frame solution is available from: https://epncb.oma.be/pub/product/referenceframe/latest/. See more information about this official reference frame solution here. Previous reference frame solutions have been archived at: https://epncb.oma.be/pub/product/referenceframe/.
The latest hybrid solution is available https://epncb.oma.be/pub/product/referenceframe/hybrid/
The hybrid product consists in:
- Positions & Velocities of EPN stations with more than 3 years
-
The positions and velocities of the EPN stations with more than 3 years of observations and without modelled post-seismic deformations are provided in the SNX and SSC format and are expressed in 4 different reference frames IGS20, ETRF2000, ETRF2014, ETRF2020.
SINEX Format SSC Format ITRS (IGS20 realization) EUR0EXPSNX_1996001_2024006_00U_SOL.SNX.Z EUR0EXPSNX_1996001_2024006_00U_SOL_IGS20.SSC ETRS89 (ETRF2000 realization) EUR0EXPSNX_1996001_2024006_00U_SOL_ETRF2000.SNX.Z EUR0EXPSNX_1996001_2024006_00U_SOL_ETRF2000.SSC ETRS89 (ETRF2014 realization) EUR0EXPSNX_1996001_2024006_00U_SOL_ETRF2014.SNX.Z EUR0EXPSNX_1996001_2024006_00U_SOL_ETRF2014.SSC ETRS89 (ETRF2020 realization) EUR0EXPSNX_1996001_2024006_00U_SOL_ETRF2020.SNX.Z EUR0EXPSNX_1996001_2024006_00U_SOL_ETRF2020.SSC Under test: For Bernese users, a CRD (EUR0EXPSNX_1996001_2024006_00U_SOL.CRD) and a VEL (EUR0EXPSNX_1996001_2024006_00U_SOL.VEL) file are available for all the stations observed within the last 270 days. For each station, the position and the velocity of the last available solution number is given.
- Positions of other EPN stations
-
The positions of the stations with less than 3 years of observations and of the 5 stations with modeled post-seismic deformations (ANKR00TUR, BUCU00ROU, ISTA00TUR, REYK00ISL, TUBI00TUR) are only provided in the SSC format and expressed in 3 different reference frames: IGb14, ETRF2000, ETRF2014.
SSC Format ITRS (IGS20 realization) EUR0EXPSNX_1996001_2024006_00U_SOL_IGS20_short.SSC ETRS89 (ETRF2000 realization) EUR0EXPSNX_1996001_2024006_00U_SOL_ETRF2000_short.SSC ETRS89 (ETRF2014 realization) EUR0EXPSNX_1996001_2024006_00U_SOL_ETRF2014_short.SSC ETRS89 (ETRF2020 realization) EUR0EXPSNX_1996001_2024006_00U_SOL_ETRF2020_short.SSC - Extended Position Time Series of EPN Stations
-
Each day, the EPN CB extends the multi-year EPN time series with recent EPN solutions to enable a quick monitoring of the EPN station positions. In practice, currently, the multi-year EPN solution from GPS week 834 till 2295 has been extended in time using the operational daily combined EPN solutions from GPS week 2296 till 2339 and the rapid daily combined solutions from GPS week 2340 till 2346.
Dynamic plots of the extended position (in IGS20 and ETRF2014) and residual position time series are available online.
- EPN discontinuities
- EPN_discontinuities.snx contains a catalogue of all discontinuities observed in the EPN multi-year solution. It defines the solution numbers (soln) used in the hybrid solution. The list has been as much as possible harmonized to agree with the IGS/ITRF discontinuity table. Unfortunately, some stations still disagree due to different period of observations.
Please cite the EPN Multi-year Position and Velocity Solutions as: Legrand J. (2022): EPN multi-year position and velocity solution CWWWW, Available from Royal Observatory of Belgium, https://doi.org/10.24414/ROB-EUREF-CWWWW.