reference frame working group report

AGU, S.F., Dec 10-14, 2007

Reference FrameWorking Group

Report

Rémi FerlandMike Piraszewski

Geodetic Survey Division

IGS08, Miami, June 2-6, 2008

Contents

• Contributors• Network

• Reference Frame Realization Status (IGS05)• Weekly solutions (1400 – Now)

• Products• Coordinates• ERP’s• Apparent Geocenter

• Summary


Contributors

• Analysis Centers (ACs):• cod Center for Orbit Determination in Europe, AIUB,

Switzerland,• emr Natural Resources Canada, Canada,• esa European Space Operations Center, ESA, Germany,• gfz GeoForschungsZentrum, Germany,• jpl Jet Propulsion Laboratory, USA,• MIT Massachusetts Institute of Technology, USA,• ngs National Oceanic and Atmospheric Administration / NGS,

USA,• sio Scripps Institution of Oceanography, USA,• grg (new) Groupe de Recherche en Geodesie Spatiale /CNES, France

• Global Network Associate Analysis Centers (GNAACs):• mit Massachusetts Institute of Technology, USA,• ncl University of Newcastle-upon-Tyne, U.K.


IGS05 Reference Frame Realization (132 Stations)

Criterions:

GeometryMonumentationCollocationPerformanceData availabilityTime seriesHistorical


Evolution of the Numberof IGS05 Stations Processed


IGS05 Status

• Initially 132 stations (Wk 1400 – 06/11/05)• Recently ~100 stations + ~6 intermittent• Inactive ~26 … Main Causes:

– Discontinuities (15)– Equipment (13)– Earthquakes (2)

– Dormant (6)– Not operational (3)– IGS05 poor velocity (1)– Poor data (1)


IGS05 Inactive Stations (26)

IGS08, Miami, June 2-6, 2008Evolution of the Number

of IGS Stations Processed

IGS08, Miami, June 2-6, 2008Stations in Recent IGS

Weekly Solutions

Up to ~350 Stations

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

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

H

N

E

Avg

. (m

m)

Std

. (m

m)

Scale=3x

Consistency:N&E ~ 3mm

H ~ 9mm


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

H

N

E

Avg

. (m

m)

Std

. (m

m)

Scale=3x

jpl: switch to AbsoluteAntenna phase center

esa: new software

Consistency:N&E ~ 1-2mm

H ~ 3-4mm


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

H

N

E

Avg

. (m

m)

Std

. (m

m)

Scale=3x

Consistency:N&E ~ 2-3mm H ~ 5-7mm


ACs Scale offset esa new software

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

w.r.t. IGS Combined

LOD

Xp

Xpr

Yp

Ypr

Excluded:cod [XY]p, [XY]prsio [XY]pr

Consistency:LOD ~ 10us[XY]p ~ 0.03-0.05mas[XY]pr ~ 0.10-0.20mas/d

IGS08, Miami, June 2-6, 2008ERPs Residuals Between

IGS Combined and Bulletin A

LOD

Xp

Xpr

Yp

Ypr

LOD(us)

Xp.01mas

Yp.01.mas

Xpr.01mas/d

Ypr.01mas/d

Avg -1 -4 5 -2 0

Std 18 5 4 11 12

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

IGS08, Miami, June 2-6, 2008IGS Combined Weekly

Apparent Geocenter

Z

YX

Scale=2x

Offset ~2mm

Annual PeriodX&Y ~4mm

Z ~5mm


Z

X

Y

Res

. (m

m)

Std

. (m

m)

ACs Apparent Geocenter Residuals and Std. w.r.t. IGS Weekly

Excluded:gfzngs (until wk 1476)

Consistency:X&Y ~ 5mm

Z ~ 10mm

Scale=2x Scale=2x


Summary (1/2)

• Reference Frame Stations 106 Active 15 Discontinuities 11 dormant + not operational

• Network of stations: 60 – 250 (+) per AC ~350 stations combined

• Some AC Parameters Excluded ERPs : cod ([XY]p, [XY]pr) ; sio ([XY]p) Geocenter : gfz, ngs (until wk 1476)


Summary (2/2)

• ACs Coordinates Consistency w.r.t.: IGS05 (N-E ~ 3 mm, H ~ 9 mm) IGS Weekly (N-E ~ 1-2 mm, H ~ 3-4 mm) IGS Cumulative (N-E ~ 2-3 mm, H ~ 5-7 mm)

• ACs ERP’s Consistency: LOD ~ 10us ( [XY]p ~ 0.03-0.05 mas; [XY]pr ~ 0.10-0.20mas/d)

• Bull A. & IGS ERPs: LOD -1 ± 10 us Xp&Yp -4&+5 ± 5mas ; Xpr&Ypr -2&0 ± 12mas/d

• ACs Geocenter Consistency: X&Y ~5 mm; Z ~ 10mm

• AC’s Residual Time Series have small bias w.r.t. each other.


Some Issues

• Provide warning or separate solutions when changes that can affect the products do occur (Usually done)

• When a change in Antenna type occur, logs and ACs databases need to be updated quickly, so proper calibration is applied.

reference frame working group report

Documents