ITRF2014: Etat d'avancement et résultats préliminaires Zuheir Altamimi, Paul Rebischung, Xavier Collilieux, Laurent Métivier

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1 ITRF2014: Etat d'avancement et résultats préliminaires Zuheir Altamimi, Paul Rebischung, Xavier Collilieux, Laurent Métivier

2 Key Points of ITRF2014 The Network: DORIS, GNSS, SLR & VLBI Linear & Non-linear motions Periodic: seasonals (e.g. annual, semi-annual) & others (e.g. draconitics for certain satellites) Post-seismic deformation Origin: DORIS vs SLR Scale : DORIS vs SLR & VLBI Polar Motion DORIS contribution? Preliminary results, but close to final

3 ITRF2014: DORIS

4 ITRF2014 : SLR

5 ITRF2014: VLBI

6 ITRF2014: GNSS Site # sites 1024 stations 1797 discontinuities

7 ITRF2014

8 Periodic signals

9 Standard residuals Brasilia GNSS site ATML-corrected before stacking Annual & semi-annual estimated ATML model provided by Tonie van Dam

10 IGS Horizontal Velocity Differences (Standard Annual+Semi-Annual)

11 IGS Vertical Velocity Differences (Standard Annual+Semi-Annual)

12 Post-Seismic Deformations

13 ITRF2014 Site affected by PSD Red Stars: EQ Epicenters Green circles: ITRF2014 sites

14 Arequipa-GPS & DORIS

15 Arequipa-GPS, SLR & DORIS

16 Santiago: GPS & DORIS

17 Fairbanks: GPS, VLBI & DORIS

18 Tsukuba GPS & VLBI

19 Origin & Scale stability

20 DORIS GPS SLR VLBI ITRF Construction Time series stacking Step 1 Long-term Solutions DORIS GPS SLR VLBI X V, EOPs Local ties Velocity equality at co-location sites Combination ITRF X V, EOPs Step 2 ITRF Specifications: Origin: SLR Scale: SLR & VLBI Orientation: Alignment to previous ITRF

21 Preserving SLR origin and SLR and VLBI scales Stacking/accumulating individual time series where the long-term origin of SLR & DORIS and scale of VLBI, SLR & DORIS are defined via internal (minimum-type) constraints, i.e. the average of the origins/scales of the time series, using: value Parameter Zero line time (Altamimi et al., 2007)

22 SLR/ILRS Origin & Scale WRT ITRF2008

23 SLR/ILRS Origin & Scale WRT ITRF2008 Annual and Semi-Annual signals + PSD removed

24 SLR Origin & Scale WRT ITRF2014P

25 DORIS/IDS Origin & Scale WRT ITRF2008

26 DORIS/IDS Origin & Scale WRT ITRF2008 Annual + Semi-annual signals removed

27 DORIS/IDS Origin & Scale WRT ITRF2014P

28 VLBI, SLR, DORIS & GPS Scales wrt ITRF2014P GPS DORIS SLR VLBI

29 VLBI, SLR, DORIS & GPS Scales wrt ITRF2014P GPS DORIS SLR VLBI

30 ITRF2014P: Horizontal Velocities

31 ITRF2014P: Vertical Velocities

32 ITRF2014P: Vertical Velocities Zoom Europe Ice melting Thulé GPS DORIS

33 ITRF2014P: Polar Motion Residuals VLBI SLR GNSS(GPS) DORIS

34 Performance (WRMS) DORIS GNSS 34

35 Conclusion 30 years of R&D on the ITRF ITRF2014: What is new? ==> Modelling the non-linear motions Estimation of the seasonal terms Application of parametric models for post-seismic deformation ITRF2014: When? By end of October, early November, 2015

36 Backup slides

37 ITRF2014 Products The usual products: Station positions, velocities and residuals; EOPs Additional/new products Geocenter motion model (amplitude & phase per component: X, Y, Z), probably from SLR only Post-seismic parametric models (amplitude A & relaxation time ) Necessary to propagate coordinates at any epoch On request: periodic signals (amplitudes & phases), per technique