1. IGS08, Miami, June 2-6, 2008 Combination of the Analysis Centers Reprocessed “SINEX” Solutions Rémi Ferland Geodetic Survey Division

2. IGS08, Miami, June 2-6, 2008 Contents Introduction Procedure Network Products Coordinates ERP’s Apparent Geocenter Summary

3. IGS08, Miami, June 2-6, 2008 Introduction Main Objective: Better meet users requirements by providing more consistent products. Current Contributors (6 ACs / 5 included): es1European Space Operations Center, ESA, Germany gf1GeoForschungsZentrum, Germany mi1Massachusetts Institute of Technology, USA ng1National Oceanic and Atmospheric Administration / NGS, USA pd1GFZ Potsdam/IPG Dresden, Germany si1(not included) Scripps Institution of Oceanography, USA,

4. IGS08, Miami, June 2-6, 2008 Procedure Used results of the test period (1042-1060) –Updated as needed Backward ( 2007 - 1994 ) Cumulative solution initialized: –Use Modified Wk 1460: Deweighted (x100) Removed marginal stations –At the beginning Not “Steady State” Rejection Criterion at 8 sigmas

5. IGS08, Miami, June 2-6, 2008 Combined Solution (2007) 425 Stations Used at least Once

6. IGS08, Miami, June 2-6, 2008 ACs Network #ACsReference Frame Stations Total Network Stations 10152 2171 31052 42542 592108 ACReference Frame Stations Total Network Stations es1126257 gf1109184 mi1127305 ng1122250 pd1108162 OverlapUsage

7. IGS08, Miami, June 2-6, 2008 Weekly Number of Stations Processed

8. IGS08, Miami, June 2-6, 2008 Weekly Number of Reference Frame Stations Processed

9. IGS08, Miami, June 2-6, 2008 ACs Coordinates Residuals Avg. & Std. w.r.t. IGS05 H N E Avg. (mm) Std. (mm) Consistency: N&E ~2-3mm H ~ 8mm Scale=3x

10. IGS08, Miami, June 2-6, 2008 ACs Coordinates Residuals Avg. & Std. w.r.t. IGS Weekly H N E Avg. (mm) Std. (mm) Consistency: N&E ~1-2mm H ~ 3mm

11. IGS08, Miami, June 2-6, 2008 ACs Coordinates Residuals Avg. & Std. w.r.t. IGS Cumulative H N E Avg. (mm) Std. (mm) Consistency: N&E ~ 2mm H ~ 5mm Scale=2x Reprocessing

12. IGS08, Miami, June 2-6, 2008 ACs Scale offset

13. IGS08, Miami, June 2-6, 2008 Combined Apparent Geocenter Position Z (mm) Y (mm) X (mm)

14. IGS08, Miami, June 2-6, 2008 Z X Y Res. (mm) Std. (mm) ACs Apparent Geocenter Residuals and Standard Deviation Excluded: gf1 Scale=2x Consistency: X&Y ~ 3-4mm H ~ 7mm

15. IGS08, Miami, June 2-6, 2008 ACs ERPs Average Weekly Residuals w.r.t. the IGS combined LOD Xp Xpr Yp Ypr Consistency: LOD ~ 10us [XY]p ~ 0.02-0.03mas [XY]pr ~ 0.08-0.10mas/d Excluded: pd1 LOD [XY]p, [XY]pr (Under Review)

16. IGS08, Miami, June 2-6, 2008 Difference Between IGS ERPs and Bulletin A LOD Xp Xpr Yp Ypr LOD (us) X 0.01mas Y 0.01.as Xr 0.01mas /d Yr 0.01mas /d Avg.-2-44-5 Std.18651215 Bull. A Pole Position Interpolated to mid-day Bull. A Pole Rate estimated from pole position

17. IGS08, Miami, June 2-6, 2008 Summary (1/3) 5 ACs Network:  All stations : Weekly ~275; Total ~425  Reference Frame Stations: 105 – 115 Some AC Parameters Excluded  ERPs : pd1  Geocenter : gf1

18. IGS08, Miami, June 2-6, 2008 Summary (2/3) ACs Coordinates Consistency w.r.t.:  IGS05(N-E ~ 2-3 mm, H ~ 8 mm)  IGS Weekly(N-E ~ 1-2 mm, H ~ 3 mm)  IGS Cumulative(N-E ~ 2 mm, H ~ 5 mm) ACs ERPs Consistency:  LOD ~ 10us  ( [XY]p ~ 0.02-0.03 mas; [XY]pr ~ 0.08-0.10mas/d) Bull. A & IGS ERPs:  LOD -2 ± 18us  ( Xp&Yp -4&4 ±6 mas; Xpr&Ypr -5&-1 ± 15mas/d) ACs Geocenter Consistency:  X & Y ~3-4 mm Z ~ 7mm

19. IGS08, Miami, June 2-6, 2008 Summary (3/3) Work in progress – some ACs are still missing ~ One month to recombine one year