ESOC IGS Reprocessing
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Transcript of ESOC IGS Reprocessing
ESOC Navigation Support OfficeIGS Workshop 2008
Miami
ESOC IGS Reprocessing
T. Springer, F. Dilssner, E. Schoenemann,
I. Romero, J. Tegedor, F. Pereira, J. Dow
ESOC Navigation Support OfficeIGS Workshop 2008
Miami
IGS Reprocessing at ESOC
• Features of New GNSS software at ESOC, Napeos: – Very fast!
» 30 minutes for a full final solution from scratch using 100 stations
» 60 minutes when using 150 stations
– Product quality excellent (see our posters)
– Ideally suited for IGS reprocessing
» But also for IGS real time!
• Reprocessing is the ideal tool for testing new models– Future improvements will come from small model changes which need
significant amounts of days (if not months) to be reanalysed.
» Being able to do that fast and efficient is key for all future progress!
ESOC wants to play a significant role in the IGS reprocessing
ESOC Navigation Support OfficeIGS Workshop 2008
Miami
Current Status of Reprocessing• Reprocessed 2007 four times since November 2007
– First time as software test for IGS operations
– Second and third time for IGS reprocessing and Albedo study
» Once without Earth Albedo and Infra-red radiation modelling (OFF)
» Once with Earth Albedo and Infra-red radiation modelling (ON, ES1)
– Fourth time after resolving issue with the CMC correction (see poster)
• Results have been analysed in some details– Orbit overlaps, orbit comparisons, ERP comparisons
– SLR validations
– Outstanding checks are:
» Clock comparisons
» Coordinate comparisons
After completion of the validation the full reprocessing will start!
ESOC Navigation Support OfficeIGS Workshop 2008
Miami
Comparison of ESOC Reprocessed Orbits
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5
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RMS Median
RM
S a
nd
Med
ian
or
Orb
it C
om
par
iso
ns
(mm
)
IGS-COD IGS-ESA IGS-ON IGS-OFF
ESOC Navigation Support OfficeIGS Workshop 2008
Miami
SLR Validation of ESOC Reprocessed Orbits
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Mean Sigma
Mea
n a
nd
Sig
ma
of t
wo
-way
SL
R O
-C R
esid
ual
s (m
m)
COD ESA ON OFF
ESOC Navigation Support OfficeIGS Workshop 2008
Miami
Comparison of ESOC Reprocessed ERP Estimates
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X-Pole (uas) Y-Pole (uas) LOD (us/day)
RM
S o
f ER
P D
iffer
ence
s o
ver
2007
IGS-COD IGS-ESA IGS-ES1
ESOC Navigation Support OfficeIGS Workshop 2008
Miami
SLR Residuals(As function of Satellite Latitude and Elevation of the Sun above the orbital plane)
ESOC Navigation Support OfficeIGS Workshop 2008
Miami
Periodic Signal in Orbit Overlap!
ESOC Navigation Support OfficeIGS Workshop 2008
Miami
Conclusions• ESOC Reprocessed solutions have very high quality!
– Completely independent 24 hour solutions
» No smoothing and no day boundary constraints!
– Small issue with CMC correction detected and fixed
» Corrected reprocessed series available
• Several comparisons show 14-day periods, e.g.,– Orbit Z-rotations, X-, Y-pole and LOD time series, orbit overlaps
– Most significant effect found in overlap of Right-Ascension of the Ascending Node
» 14-day period in RAAN overlap dominating the overlap statistics
» Explanation missing (see also our poster)• IERS Sub-daily Polar Motion model too simple?
• SLR validation of the orbits confirms the high quality– Difference between SLR observations and GPS orbits remains
– Earth Albedo and Infra-red radiation may give the explanation
» However, the Napeos model is too simple
ESOC ready to reprocess all IGS data since 1994
ESOC Navigation Support OfficeIGS Workshop 2008
Miami
Thank You!