Improving global reference frame realizations by correcting for non-tidal loading displacements
Abstract
Conventional realizations of the terrestrial reference frame (TRF) describe 3D station positions by offsets at a given reference epoch and constant linear motions (velocities) over time. The linear model approximates the so called regularized station position which is the instantaneous position corrected for well-known and accurate geophysical models such as Earth tides, ocean tides, etc. Thereby, the quality and the completeness of the correction models is essential for an accurate approximation through the linear station motion model. Beside the conventional correction models summarized in the IERS Conventions 2010 (Petit and Luzum., 2010), the most recent call for participation of the IERS ITRS Product Centre hosted by IGN (France) also mentions the possibility to correct for site displacements caused by non-tidal effects. Up to now, only a few global reference frame realizations such as the DTRF2014 (Seitz et al., 2016) took site displacement corrections due to non-tidal effects into account.
In this presentation, we outline the importance of applying site displacement corrections caused by atmospheric, oceanic and hydrological non-tidal loading (NT-L) when computing a global reference frame. We evaluate the impact of these corrections w.r.t. a conventional TRF solution (no NT-L corrections applied). It will be clearly shown that the application of NT-L corrections is beneficial for the accuracy, the geodetic datum and the reliability of the TRF solution. Furthermore, the impact when accounting for NT-L effects already at observation level (for SLR and VLBI) compared to the normal equation level of the Gauss-Markov least squares adjustment process is quantified. Based on the results presented in this contribution, the current plan for the DTRF2020 solution is that this solution will be corrected for NT-L effects if the quality of the NT-L correction models is sufficient.- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2019
- Bibcode:
- 2019AGUFM.G11A..01B
- Keywords:
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- 1229 Reference systems;
- GEODESY AND GRAVITY;
- 1295 Integrations of techniques;
- GEODESY AND GRAVITY;
- 1299 General or miscellaneous;
- GEODESY AND GRAVITY