GRACE Gravity Field Recovery
at AIUB: Status Report
Adrian JäggiG. Beutler, L. Mervart, U. Meyer, R. Rummel, R. Dach
August 31, 2009
Astronomical Institute University of Bern
IAG
Scientific
Assembly
2009
Buenos Aires
Argentina
08.31. – 09.04.
GRACE Gravity Field Recovery
at AIUB: Status Report
Adrian JäggiG. Beutler, L. Mervart, U. Meyer, R. Rummel, R. Dach
August 31, 2009
Astronomical Institute University of Bern
IAG
Scientific
Assembly
2009
Buenos Aires
Argentina
08.31. – 09.04.
Adrian JäggiG. Beutler, L. Mervart, U. Meyer, R. Rummel, R. Dach
August 31, 2009
GRACE Gravity Field Recovery
at AIUB: Status Report
Adrian JäggiG. Beutler, L. Mervart, U. Meyer, R. Rummel, R. Dach
August 31, 2009
Astronomical Institute University of Bern
IAG
Scientific
Assembly
2009
Buenos Aires
Argentina
08.31. – 09.04.
Adrian JäggiG. Beutler, L. Mervart, U. Meyer, R. Rummel, R. Dach
August 31, 2009
Adrian JäggiG. Beutler, L. Mervart, U. Meyer, R. Rummel, R. Dach
August 31, 2009
Institute of Advanced Geodesy Technical University of Prague
GRACE Gravity Field Recovery
at AIUB: Status Report
Adrian JäggiG. Beutler, L. Mervart, U. Meyer, R. Rummel, R. Dach
August 31, 2009
Astronomical Institute University of Bern
IAG
Scientific
Assembly
2009
Buenos Aires
Argentina
08.31. – 09.04.
Adrian JäggiG. Beutler, L. Mervart, U. Meyer, R. Rummel, R. Dach
August 31, 2009
Adrian JäggiG. Beutler, L. Mervart, U. Meyer, R. Rummel, R. Dach
August 31, 2009
Institute of Advanced Geodesy Technical University of Prague
Adrian JäggiG. Beutler, L. Mervart, U. Meyer, R. Rummel, R. Dach
August 31, 2009
Institute of Astron. & Physical Geodesy Technical University of Munich
GRACE Gravity Field Recovery
at AIUB: Status Report
Adrian JäggiG. Beutler, L. Mervart, U. Meyer, R. Rummel, R. Dach
August 31, 2009
Astronomical Institute University of Bern
IAG
Scientific
Assembly
2009
Buenos Aires
Argentina
08.31. – 09.04.
Adrian JäggiG. Beutler, L. Mervart, U. Meyer, R. Rummel, R. Dach
August 31, 2009
Adrian JäggiG. Beutler, L. Mervart, U. Meyer, R. Rummel, R. Dach
August 31, 2009
Institute of Advanced Geodesy Technical University of Prague
Adrian JäggiG. Beutler, L. Mervart, U. Meyer, R. Rummel, R. Dach
August 31, 2009
Institute of Astron. & Physical Geodesy Technical University of Munich
Adrian JäggiG. Beutler, L. Mervart, U. Meyer, R. Rummel, R. Dach
August 31, 2009
Institute for Advanced Study Technical University of Munich
Aug. 31, 2009
IAG
Scientific
Assembly
Adrian Jäggi
2
Session 2.2
Introduction
Celestial Mechanics Approach =Gravity field recovery is rigorously treated as an extended orbit determination problem, i.e., all available measurements contribute to one and the same set of parameters
Aug. 31, 2009
IAG
Scientific
Assembly
Adrian Jäggi
2
Session 2.2
Introduction
Celestial Mechanics Approach =Gravity field recovery is rigorously treated as an extended orbit determination problem, i.e., all available measurements contribute to one and the same set of parameters
The approach is flexible with respect to
Aug. 31, 2009
IAG
Scientific
Assembly
Adrian Jäggi
2
Session 2.2
Introduction
Celestial Mechanics Approach =Gravity field recovery is rigorously treated as an extended orbit determination problem, i.e., all available measurements contribute to one and the same set of parameters
The approach is flexible with respect to • Parameter set-up
Aug. 31, 2009
IAG
Scientific
Assembly
Adrian Jäggi
2
Session 2.2
Introduction
Celestial Mechanics Approach =Gravity field recovery is rigorously treated as an extended orbit determination problem, i.e., all available measurements contribute to one and the same set of parameters
The approach is flexible with respect to • Parameter set-up• Normal equation modifications
Aug. 31, 2009
IAG
Scientific
Assembly
Adrian Jäggi
2
Session 2.2
Introduction
Celestial Mechanics Approach =Gravity field recovery is rigorously treated as an extended orbit determination problem, i.e., all available measurements contribute to one and the same set of parameters
The approach is flexible with respect to • Parameter set-up• Normal equation modifications
� Generation of ensembles of solutions
Aug. 31, 2009
IAG
Scientific
Assembly
Adrian Jäggi
3
Session 2.2
Correlations over epochs are due to the GPS phase ambiguities
Studies on the GPS partCorrelations of kinematic positions over epochs
Cor
rela
tion
mat
rix(b
and-
limite
d)
Aug. 31, 2009
IAG
Scientific
Assembly
Adrian Jäggi
3
Session 2.2
Correlations over epochs are due to the GPS phase ambiguities
Studies on the GPS partCorrelations of kinematic positions over epochs
Cor
rela
tion
mat
rix(b
and-
limite
d)C
orre
latio
nm
atrix
(ban
d-lim
ited)
Aug. 31, 2009
IAG
Scientific
Assembly
Adrian Jäggi
3
Session 2.2
Correlations over epochs are due to the GPS phase ambiguities
Studies on the GPS partCorrelations of kinematic positions over epochs
Cor
rela
tion
mat
rix(b
and-
limite
d)C
orre
latio
nm
atrix
(ban
d-lim
ited)
Cor
rela
tion
mat
rix(b
and-
limite
d)
Aug. 31, 2009
IAG
Scientific
Assembly
Adrian Jäggi
4
Session 2.2
Studies on the GPS part
Observations:
GPS phase
Orbit reconstruction from kinematic positions
Aug. 31, 2009
IAG
Scientific
Assembly
Adrian Jäggi
4
Session 2.2
Studies on the GPS part
Observations:
GPS phase
Orbit reconstruction from kinematic positions
Observations:
KIN (w/o corr.)
Aug. 31, 2009
IAG
Scientific
Assembly
Adrian Jäggi
4
Session 2.2
Studies on the GPS part
Observations:
GPS phase
Orbit reconstruction from kinematic positions
Observations:
KIN (w/o corr.)
KIN (with corr.)
Aug. 31, 2009
IAG
Scientific
Assembly
Adrian Jäggi
4
Session 2.2
Studies on the GPS part
Observations:
GPS phase
Orbit reconstruction from kinematic positions
Observations:
KIN (w/o corr.)
KIN (with corr.)
Correlations over epochs are very important for orbit reconstruction
Aug. 31, 2009
IAG
Scientific
Assembly
Adrian Jäggi
5
Session 2.2
Studies on the GPS part
Reference field:
EIGEN-GL04C
Differences:
GRCB (w/o corr.)
Gravity field recovery from kinematic positions
Aug. 31, 2009
IAG
Scientific
Assembly
Adrian Jäggi
5
Session 2.2
Studies on the GPS part
Reference field:
EIGEN-GL04C
Differences:
GRCB (w/o corr.)
Gravity field recovery from kinematic positions
GRCB (with corr.)
Aug. 31, 2009
IAG
Scientific
Assembly
Adrian Jäggi
5
Session 2.2
Studies on the GPS part
Reference field:
EIGEN-GL04C
Differences:
GRCB (w/o corr.)
Gravity field recovery from kinematic positions
GRCB (with corr.)
Correlations over epochs are less important for gravity field recovery
Aug. 31, 2009
IAG
Scientific
Assembly
Adrian Jäggi
6
Session 2.2
Nominal K-band processing
Static field • SH expansion up to degree 150Variations • Not yet modeled
Preliminary solution AIUB-GRACE02Sp
Aug. 31, 2009
IAG
Scientific
Assembly
Adrian Jäggi
6
Session 2.2
Nominal K-band processing
Static field • SH expansion up to degree 150Variations • Not yet modeled
Preliminary solution AIUB-GRACE02Sp
Data • GRACE kinematic positions 2006/07 • Level 1B K-band range-rates 2006/07
Aug. 31, 2009
IAG
Scientific
Assembly
Adrian Jäggi
6
Session 2.2
Nominal K-band processing
Static field • SH expansion up to degree 150Variations • Not yet modeled
Preliminary solution AIUB-GRACE02Sp
Data • GRACE kinematic positions 2006/07 • Level 1B K-band range-rates 2006/07
Orbits • Initial conditions every 24h• Accelerations over 15min
K-band • No additional parameters• Correlations not modeled
Aug. 31, 2009
IAG
Scientific
Assembly
Adrian Jäggi
6
Session 2.2
Nominal K-band processing
Static field • SH expansion up to degree 150Variations • Not yet modeled
Preliminary solution AIUB-GRACE02Sp
Data • GRACE kinematic positions 2006/07 • Level 1B K-band range-rates 2006/07
Orbits • Initial conditions every 24h• Accelerations over 15min
K-band • No additional parameters• Correlations not modeled
A priori • EGM96 up to degree 150
Aug. 31, 2009
IAG
Scientific
Assembly
Adrian Jäggi
6
Session 2.2
Nominal K-band processing
Static field • SH expansion up to degree 150Variations • Not yet modeled
Preliminary solution AIUB-GRACE02Sp
Data • GRACE kinematic positions 2006/07 • Level 1B K-band range-rates 2006/07
Orbits • Initial conditions every 24h• Accelerations over 15min
K-band • No additional parameters• Correlations not modeled
A priori • EGM96 up to degree 150
Accelerometer • Level 1B data from 2006/07
Aug. 31, 2009
IAG
Scientific
Assembly
Adrian Jäggi
6
Session 2.2
Nominal K-band processing
Static field • SH expansion up to degree 150Variations • Not yet modeled
Preliminary solution AIUB-GRACE02Sp
Data • GRACE kinematic positions 2006/07 • Level 1B K-band range-rates 2006/07
Orbits • Initial conditions every 24h• Accelerations over 15min
K-band • No additional parameters• Correlations not modeled
A priori • EGM96 up to degree 150
Accelerometer • Level 1B data from 2006/07
• IERS 2003 solid Earth tides• EOT08a ocean tides• AOD1B dealiasing
Background
Aug. 31, 2009
IAG
Scientific
Assembly
Adrian Jäggi
7
Session 2.2
Comparison of AIUB-GRACE02Sp with external solution
Reference field:
ITG-GRACE03S
Differences:
EIGEN-05S
Nominal K-band processing
AIUB-2006
Aug. 31, 2009
IAG
Scientific
Assembly
Adrian Jäggi
7
Session 2.2
Comparison of AIUB-GRACE02Sp with external solution
Reference field:
ITG-GRACE03S
Differences:
EIGEN-05S
Nominal K-band processing
AIUB-2006
AIUB-2007
Aug. 31, 2009
IAG
Scientific
Assembly
Adrian Jäggi
7
Session 2.2
Comparison of AIUB-GRACE02Sp with external solution
Reference field:
ITG-GRACE03S
Differences:
EIGEN-05S
Nominal K-band processing
AIUB-2006
AIUB-2007
Differences:
AIUB-02Sp
Aug. 31, 2009
IAG
Scientific
Assembly
Adrian Jäggi
7
Session 2.2
Comparison of AIUB-GRACE02Sp with external solution
Reference field:
ITG-GRACE03S
Differences:
EIGEN-05S
Nominal K-band processing
AIUB-2006
AIUB-2007
Differences:
AIUB-02Sp
Overall quality is very promising, C20 is problematic
Aug. 31, 2009
IAG
Scientific
Assembly
Adrian Jäggi
8
Session 2.2
Nominal K-band processing
10.3
21.9
15.0
04.4
03.7
24.3
ITG03S
22.222.522.622.623.3EUREF (GPS)
15.314.815.514.415.1Canada (GPS)
11.210.611.810.711.0Japan (GPS)
06.2
05.4
24.2
GGM03S
05.0
04.4
25.0
AIUB2007
04.6
04.0
24.1
GGM03C
06.3
05.9
24.5
EIGEN5S
EIGEN5C
04.9
04.1
24.4
Germany (GPS)
Germany (EUVN)
Australia (GPS)
Comparison with levelling
Aug. 31, 2009
IAG
Scientific
Assembly
Adrian Jäggi
9
Session 2.2
Nominal K-band processingK-band range-rate residuals
Gravity field:
static part only
Aug. 31, 2009
IAG
Scientific
Assembly
Adrian Jäggi
9
Session 2.2
Nominal K-band processingK-band range-rate residuals
Gravity field:
static part only
Aug. 31, 2009
IAG
Scientific
Assembly
Adrian Jäggi
9
Session 2.2
Nominal K-band processingK-band range-rate residuals
Gravity field:
static part only
static + variability
Aug. 31, 2009
IAG
Scientific
Assembly
Adrian Jäggi
9
Session 2.2
Nominal K-band processingK-band range-rate residuals
Gravity field:
static part only
static + variability
Time variable signals are reflected in the residuals
Aug. 31, 2009
IAG
Scientific
Assembly
Adrian Jäggi
10
Session 2.2
Studies on the K-band partTime variability in the year 2007
Aug. 31, 2009
IAG
Scientific
Assembly
Adrian Jäggi
10
Session 2.2
Studies on the K-band partTime variability in the year 2007
Free solutions up to degree 30, artifacts are pronounced
Aug. 31, 2009
IAG
Scientific
Assembly
Adrian Jäggi
11
Session 2.2
Alternative processing strategies
Studies on the K-band part
Reference field:
ITG-GRACE03S
Differences:
RR: lw, acc
Aug. 31, 2009
IAG
Scientific
Assembly
Adrian Jäggi
11
Session 2.2
Alternative processing strategies
Studies on the K-band part
Reference field:
ITG-GRACE03S
Differences:
RR: lw, acc
RR: nw, acc
Aug. 31, 2009
IAG
Scientific
Assembly
Adrian Jäggi
11
Session 2.2
Alternative processing strategies
Studies on the K-band part
Reference field:
ITG-GRACE03S
Differences:
RR: lw, acc
RR: nw, acc
R: lw, acc
Aug. 31, 2009
IAG
Scientific
Assembly
Adrian Jäggi
11
Session 2.2
Alternative processing strategies
Studies on the K-band part
Reference field:
ITG-GRACE03S
Differences:
RR: lw, acc
RR: nw, acc
R: lw, acc
R: nw, acc
Aug. 31, 2009
IAG
Scientific
Assembly
Adrian Jäggi
11
Session 2.2
Alternative processing strategies
Studies on the K-band part
Reference field:
ITG-GRACE03S
Differences:
RR: lw, acc
RR: nw, acc
R: lw, acc
R: nw, acc
Range processing is dominated by systematic errors
Aug. 31, 2009
IAG
Scientific
Assembly
Adrian Jäggi
11
Session 2.2
Alternative processing strategies
Studies on the K-band part
Reference field:
ITG-GRACE03S
Differences:
RR: lw, acc
RR: nw, acc
R: lw, acc
R: nw, acc
Range processing is dominated by systematic errors
R: nw, pls
Aug. 31, 2009
IAG
Scientific
Assembly
Adrian Jäggi
11
Session 2.2
Alternative processing strategies
Studies on the K-band part
Reference field:
ITG-GRACE03S
Differences:
RR: lw, acc
RR: nw, acc
R: lw, acc
R: nw, acc
Range processing is dominated by systematic errors
R: nw, pls
R: nw, pls, corr
Aug. 31, 2009
IAG
Scientific
Assembly
Adrian Jäggi
12
Session 2.2
Conclusions
Aug. 31, 2009
IAG
Scientific
Assembly
Adrian Jäggi
12
Session 2.2
Conclusions
• Correlations in time of kinematic positions are very important for orbit reconstruction, but not that important for gravity field recovery
Aug. 31, 2009
IAG
Scientific
Assembly
Adrian Jäggi
12
Session 2.2
Conclusions
• Correlations in time of kinematic positions are very important for orbit reconstruction, but not that important for gravity field recovery
• Quality of AIUB K-band solutions is steadily improving and longer data spans are currently being processed. Further investigations are needed concerning the
Aug. 31, 2009
IAG
Scientific
Assembly
Adrian Jäggi
12
Session 2.2
Conclusions
• Correlations in time of kinematic positions are very important for orbit reconstruction, but not that important for gravity field recovery
• Quality of AIUB K-band solutions is steadily improving and longer data spans are currently being processed. Further investigations are needed concerning the
• C20 estimate
Aug. 31, 2009
IAG
Scientific
Assembly
Adrian Jäggi
12
Session 2.2
Conclusions
• Correlations in time of kinematic positions are very important for orbit reconstruction, but not that important for gravity field recovery
• Quality of AIUB K-band solutions is steadily improving and longer data spans are currently being processed. Further investigations are needed concerning the
• C20 estimate• time variability
Aug. 31, 2009
IAG
Scientific
Assembly
Adrian Jäggi
12
Session 2.2
Conclusions
• Correlations in time of kinematic positions are very important for orbit reconstruction, but not that important for gravity field recovery
• Quality of AIUB K-band solutions is steadily improving and longer data spans are currently being processed. Further investigations are needed concerning the
• C20 estimate• time variability• range vs. range-rate
Aug. 31, 2009
IAG
Scientific
Assembly
Adrian Jäggi
12
Session 2.2
Conclusions
• Correlations in time of kinematic positions are very important for orbit reconstruction, but not that important for gravity field recovery
• Quality of AIUB K-band solutions is steadily improving and longer data spans are currently being processed. Further investigations are needed concerning the
• C20 estimate• time variability• range vs. range-rate• orbit parametrization
Aug. 31, 2009
IAG
Scientific
Assembly
Adrian Jäggi
12
Session 2.2
Conclusions
• Correlations in time of kinematic positions are very important for orbit reconstruction, but not that important for gravity field recovery
• Quality of AIUB K-band solutions is steadily improving and longer data spans are currently being processed. Further investigations are needed concerning the
• C20 estimate• time variability• range vs. range-rate• orbit parametrization• observation weighting
Aug. 31, 2009
IAG
Scientific
Assembly
Adrian Jäggi
12
Session 2.2
Conclusions
• Correlations in time of kinematic positions are very important for orbit reconstruction, but not that important for gravity field recovery
• Quality of AIUB K-band solutions is steadily improving and longer data spans are currently being processed. Further investigations are needed concerning the
• C20 estimate• time variability• range vs. range-rate• orbit parametrization• observation weighting• …
Aug. 31, 2009
IAG
Scientific
Assembly
Adrian Jäggi
12
Session 2.2
Conclusions
• Correlations in time of kinematic positions are very important for orbit reconstruction, but not that important for gravity field recovery
• Quality of AIUB K-band solutions is steadily improving and longer data spans are currently being processed. Further investigations are needed concerning the
• C20 estimate• time variability• range vs. range-rate• orbit parametrization• observation weighting• …• …
Aug. 31, 2009
IAG
Scientific
Assembly
Adrian Jäggi
12
Session 2.2
Conclusions
• Correlations in time of kinematic positions are very important for orbit reconstruction, but not that important for gravity field recovery
• Quality of AIUB K-band solutions is steadily improving and longer data spans are currently being processed. Further investigations are needed concerning the
• C20 estimate• time variability• range vs. range-rate• orbit parametrization• observation weighting• …• …
