IGS08, Miami, June 2-6, 2008

Combination of the Analysis Centers Reprocessed “SINEX” Solutions

Rémi Ferland

Geodetic Survey Division

IGS08, Miami, June 2-6, 2008

Contents

• Introduction

• Procedure

• Network

• Products• Coordinates

• ERP’s

• Apparent Geocenter

• Summary

IGS08, Miami, June 2-6, 2008

Introduction

• Main Objective:• Better meet users requirements by providing more consistent

products.

• Current Contributors (6 ACs / 5 included):• es1 European Space Operations Center, ESA,

Germany • gf1 GeoForschungsZentrum, Germany• mi1 Massachusetts Institute of Technology, USA • ng1 National Oceanic and Atmospheric

Administration / NGS, USA • pd1 GFZ Potsdam/IPG Dresden, Germany• si1 (not included) Scripps Institution of

Oceanography, USA,

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

IGS08, Miami, June 2-6, 2008

Combined Solution (2007)

425 Stations Used at least Once

IGS08, Miami, June 2-6, 2008

ACs Network

#ACs Reference Frame

Stations

Total Network Stations

1 0 152

2 1 71

3 10 52

4 25 42

5 92 108

AC Reference Frame

Stations

Total Network Stations

es1 126 257

gf1 109 184

mi1 127 305

ng1 122 250

pd1 108 162

OverlapUsage

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

Processed

IGS08, Miami, June 2-6, 2008Weekly Number of Reference

Frame Stations Processed

IGS08, Miami, June 2-6, 2008ACs Coordinates Residuals

Avg. & Std. w.r.t. IGS05

H

N

E

Avg

. (m

m)

Std

. (m

m)

Consistency:N&E ~2-3mm

H ~ 8mm

Scale=3x

IGS08, Miami, June 2-6, 2008ACs Coordinates Residuals

Avg. & Std. w.r.t. IGS Weekly

H

N

E

Avg

. (m

m)

Std

. (m

m)

Consistency:N&E ~1-2mm

H ~ 3mm

IGS08, Miami, June 2-6, 2008ACs Coordinates Residuals

Avg. & Std. w.r.t. IGS Cumulative

H

N

E

Avg

. (m

m)

Std

. (m

m)

Consistency:N&E ~ 2mm

H ~ 5mm

Scale=2x

Reprocessing

IGS08, Miami, June 2-6, 2008

ACs Scale offset

IGS08, Miami, June 2-6, 2008Combined Apparent

Geocenter Position

Z(mm)

Y(mm)X(mm)

IGS08, Miami, June 2-6, 2008

Z

X

Y

Res

. (m

m)

Std

. (m

m)

ACs Apparent Geocenter Residuals and Standard Deviation

Excluded:gf1

Scale=2x

Consistency:X&Y ~ 3-4mm H ~ 7mm

IGS08, Miami, June 2-6, 2008ACs ERPs Average Weekly

Residuals w.r.t. the IGS combinedLOD Xp

Xpr

Yp

YprConsistency:LOD ~ 10us[XY]p ~ 0.02-0.03mas[XY]pr ~ 0.08-0.10mas/d

Excluded:pd1 LOD [XY]p, [XY]pr(Under Review)

IGS08, Miami, June 2-6, 2008Difference Between

IGS ERPs and Bulletin ALOD Xp

Xpr

Yp

YprLOD

(us)

X0.01mas

Y0.01.as

Xr0.01mas/d

Yr0.01mas/d

Avg. -2 -4 4 -5 -1

Std. 18 6 5 12 15

Bull. A Pole Position Interpolated to mid-dayBull. A Pole Rate estimated from pole position

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

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

IGS08, Miami, June 2-6, 2008

Summary (3/3)

• Work in progress – some ACs are still missing

• ~ One month to recombine one year