How does station position modelling affect the VLBI scale in ITRF2020?
Other conference contribution, 2024
In the most recent realization of the International Terrestrial Reference System, the ITRF2020, it was found that the VLBI scale parameter has a positive drift after 2013.75.
While several possible reasons for this apparent VLBI scale drift are being discussed in the IVS community, a clear explanation for the issue has not been identified yet.
In this study, we investigate reasons for the apparent VLBI scale drift in the ITRF2020 using the CATREF software, applying the same approach as used for the ITRF2020 production.
We compare the models of discontinuities and post-seismic deformation used for VLBI station positions and velocities with those for co-located GNSS stations, and estimate the impact of these model differences on the VLBI scale drift.
The analysis reveals that one of the main factors causing the scale drift can be non-linear behavior of the Ny-Ålesund station and Wettzell station.
While several possible reasons for this apparent VLBI scale drift are being discussed in the IVS community, a clear explanation for the issue has not been identified yet.
In this study, we investigate reasons for the apparent VLBI scale drift in the ITRF2020 using the CATREF software, applying the same approach as used for the ITRF2020 production.
We compare the models of discontinuities and post-seismic deformation used for VLBI station positions and velocities with those for co-located GNSS stations, and estimate the impact of these model differences on the VLBI scale drift.
The analysis reveals that one of the main factors causing the scale drift can be non-linear behavior of the Ny-Ålesund station and Wettzell station.
ITRF2020
Scale
Author
Masafumi Ishigaki
Geospatial Information Authority of Japan
Chalmers, Space, Earth and Environment, Onsala Space Observatory
Karine le Bail
Chalmers, Space, Earth and Environment, Onsala Space Observatory
Maxime Mouyen
Chalmers, Space, Earth and Environment, Onsala Space Observatory
Rüdiger Haas
Chalmers, Space, Earth and Environment, Onsala Space Observatory
Tobias Nilsson
Chalmers, Space, Earth and Environment, Space Geodesy and Geodynamics
The Swedish Mapping, Cadastral and Land Registration Authority
13th General Meeting of the International VLBI Service for Geodesy and Astrometry
Tsukuba, Japan,
Tsukuba, Japan,
Subject Categories (SSIF 2025)
Other Earth Sciences