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IERS Message No. 541                                   December 01, 2025
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Release of DTRF2020-u2023 


Dear colleagues,

We are pleased to inform you that the DTRF2020 update, DTRF2020-u2023
has been released on 28. November 2025. It is available from Zenodo

https://doi.org/10.5281/zenodo.17432063

and via the DGFI website http://dtrf.dgfi.tum.de.

Compared to DTRF2020, the update introduces
- three more years of data provided by the four IAG Technique Services
  covering the years 2021-2023
- the approximation of post-seismic deformation (PSD) for new stations
  or stations with a short time spans in DTRF2020.
- the consideration of new calibrations for 10 GNSS receiver antennas. 
  This also includes correcting DTRF2020 station positions by mean
  coordinate offsets. For this, we reprocessed the GNSS part of DTRF2020
  taking these offsets into account for their respective time of 
  validity.
- the consideration of new local tie measurements
- the DTRF2020-u2023 datum realization based on the full time series of
  SLR data for the origin and the full series of GNSS and VLBI data for
  the scale.

The DTRF2020-u2023 release comprises (please see the website and the
solution description for details):
- one SINEX file per technique (for coordinates only, full variance-
  covariance matrix)
- an EOP file in IERS 20 C04 format
- PSD approximation time series for the DTRF2020 period
- NTL displacements (CM-and CF-related) per station and component
- NTL offsets and trends removed a priori from the input NTL model time
  series
- station position residual time series
- SLR translation time series
- a short solution description

We thank all the colleagues who analyzed the DTRF2020-u2023 preliminary
solution. Your feedback was very helpful to improve the DTRF2020-u2023.
Any further feedback on the DTRF2020-u2023 is very welcome and helpful
to improve the DTRF also in the future.
In case you have any questions, please do not hesitate to contact us.

We thank all the Technique Services of the IAG, the IERS GGFC and the
ITRS Center for their great efforts in providing the input data and for
the good cooperation!
We thank also the IERS Central Bureau for their assistance regarding
publication and communication.

Best regards,
on behalf of the DGFI-TUM ITRS CC team,
Manuela Seitz


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