1. Reference Frame Working Group
Progress on recommendations made at the 2016 IGS workshop in Sydney, Australia
Presented to the IGS Governing Board and Associate Members on 11 December 2016

2. The group recommends: Prepare, implement, test and adopt the IGS14/igs14.atx framework Revisit the consistency of repro2 station position time series with loading models
Paul Rebischung
Reference Frame Splinter Session Summary Recommendations
Splinter session discussions were mostly focused on the new ITRF2014 realization and on the post-seismic deformation models coming along with it. The procedure for the preparation and implementation of its IGS realization have been defined. IGS14 is planned to be adopted in the second half of 2016, together with the updated ANTEX file igs14.atx.

3. Progress since Sydney: IGS14/igs14.atx
Preliminary IGS14/igs14.atx made available to ACs in July
Some parallel IGS14-based AC solutions received since September
Test SINEX combinations performed; no unexpected results
Impact of the switch to IGS14/igs14.atx studied by re-combining the AC repro2 SINEX solutions in the new framework
Poster G41A-0998, Thursday, 15 Dec, 10:20–12:20
Waiting for IERS DB and IGS GB / ACs approval to:
Set the date of the official switch (GPS week 1934 – 29 Jan 2017?)
Announce the switch via IGS-MAIL (this week?)

4. Progress since Sydney: repro2 vs. loading
Li et al., EGU 2016: “A comparison of three environmental load combinations with repro2 residuals”
Similar results as obtained by Ray et al. (2011) using repro1 series
Loading corrections reduce WRMS and annual amplitude for most stations, but most variability remains (esp. in horizontal)
No significant improvement in loading models, nor in IGS position time series
Median WRMS reduction
Median annual amp. reduction
East
North Up
Ray et al. (2011)
1.6 %
3.8 %
15.2 %
8 %
22 %
48 %
Li et al. (2016)
2.8 %
5.0 %
11.5 %
13%
14%
44%

5. Future Work IGS14: Long-term objective: Official adoption
Prepare new IGS cumulative solution based on repro2 solutions and improved discontinuity list
Long-term objective:
Study, understand and mitigate errors in IGS station position time series

6. Contact: Paul Rebischung - paul.rebischung@ign.fr
Thank You
Contact:
Paul Rebischung -