[IGSMAIL-1176] Wk 0825-9 Final Orbits
AC
AC
Thu Jan 4 09:32:33 PST 1996
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IGS Electronic Mail Thu Jan 4 9:32:33 PST 1996 Message Number 1176
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Author: AC Coordinator
Subject: Wk 0825-9 Final Orbits
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IGS Final orbits/clocks completed and put onto CDDIS (Weeks 825 - 829)
(Oct 29 - Dec 02, 1995)
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The IGS Rapid Orbits for this period were recomputed using up to date
orbits and the final EOP values of Bulletin B, published by IERS. ( Daily
values, page 2 of Bull. B ) The EOP were corrected for the difference
between the IERS pole series and ITRF as published in the IERS 1993 Annual
Report (p. II-19, Table II-3), so both the IGS orbits and the associated
ERP files are consistent with ITRF93 (current epoch).
We have downloaded all the submitted ephemeris and ERP files from CDDIS
before the final orbit/clock combination to ensure that the sets are
complete and up to date. In the final combination we have largely followed
the actions taken during the Rapid orbit generation and since there were
very few orbit resubmissions, both the IGS Rapid and Final orbits are
virtually the same except for the orientation difference (IGS mean pole and
Bull.B). Orbit evaluation are also nearly the same, since we used centre
specific ERP in the long arc evaluations. For more information see the
corresponding summary files on CDDIS.
The clock solution alignment and centre clock weight assignment are based
on non-SA broadcast satellite corrections only (PRN12, 15, 28). This should
result in an objective clock weighting, provided that the non-SA satellites
are representative of centre clock solution quality. Starting with the GPS
week 756 the new IGS erp format (see IGSMAIL# 662) is used by all Analysis
Centres and for the IGS erp files. ERP rates, whenever given, are also
utilized in both orbit combination and the long arc evaluation.
PRODUCTS GENERATED:
The resulting final IGS ephemeris and clocks are in daily files in the SP3
format. The sat. orb. accuracy codes displayed in the headers are based on
weighted RMS for each satellite. Note that each file contains all the submitted
satellites. If a satellite or centre had to be excluded from the combination it
is noted in the summary file along with the reason for doing so.
The IGS FINAL ORBIT files generated and uploaded into CDDIS @ NASA/GSFC are:
IGS08250-6.SP3 IGS GPS orbit/clock files for days 0-6, week 0825
IGS08260-6.SP3 IGS GPS orbit/clock files for days 0-6, week 0826
IGS08270-6.SP3 IGS GPS orbit/clock files for days 0-6, week 0827
IGS08280-6.SP3 IGS GPS orbit/clock files for days 0-6, week 0828
IGS08290-6.SP3 IGS GPS orbit/clock files for days 0-6, week 0829
IGS08257.ERP EOP associated with the above orbits (Bull. B aligned to ITRF)
IGS08267.ERP EOP associated with the above orbits (Bull. B aligned to ITRF)
IGS08277.ERP EOP associated with the above orbits (Bull. B aligned to ITRF)
IGS08287.ERP EOP associated with the above orbits (Bull. B aligned to ITRF)
IGS08297.ERP EOP associated with the above orbits (Bull. B aligned to ITRF)
IGS08257.SUM Complete summary/statistics report
IGS08267.SUM Complete summary/statistics report
IGS08277.SUM Complete summary/statistics report
IGS08287.SUM Complete summary/statistics report
IGS08297.SUM Complete summary/statistics report
The old Rapid Orbit files have been renamed (on CDDIS) to:
(Note this is temporary, based on discussions with ACs and GB and may be
changed)
IGR08250-6.SP3 Rapid service orbits/clocks for days 0-6, week 0825
IGR08260-6.SP3 Rapid service orbits/clocks for days 0-6, week 0826
IGR08270-6.SP3 Rapid service orbits/clocks for days 0-6, week 0827
IGR08280-6.SP3 Rapid service orbits/clocks for days 0-6, week 0828
IGR08290-6.SP3 Rapid service orbits/clocks for days 0-6, week 0829
IGR08257.ERP IGS Mean EOP associated with the above orbits
IGR08267.ERP IGS Mean EOP associated with the above orbits
IGR08277.ERP IGS Mean EOP associated with the above orbits
IGR08287.ERP IGS Mean EOP associated with the above orbits
IGR08297.ERP IGS Mean EOP associated with the above orbits
IGR08257.SUM Rapid service complete summary/statistic report
IGR08267.SUM Rapid service complete summary/statistic report
IGR08277.SUM Rapid service complete summary/statistic report
IGR08287.SUM Rapid service complete summary/statistic report
IGR08297.SUM Rapid service complete summary/statistic report
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REMARKS/CORRECTIONS:
************* NOTE: ***************************
Since Wk803 the IGS Rapid combinations are performed directly in the ITRF frame
without any EOP alignments. The associated erp files (IGR0WWW7.erp) contain
weighted averages of all submitted erp solutions given at 12h UT each day
(using the orbit weights), augmented with the current IERS Bull.A UT1-UTC.
Consequently, since Wk 803, the IGR erp contains 7 daily EOP values at 12h UT,
unlike the Final orbit erp (and the Rapid orbit erp prior Wk 803) which
contain 9 daily IERS EOP values at 0h UT to facilitate accurate interpolation
at the beginning and the end of the week.
***********************************************
The following table shows the average statistics of the Final orbit/clock
combination for the current period (Wks 0825-0829).
Start: 95 Oct 29 / wk825
End: 95 Dec 02 / wk829
STA DX DY DZ RX RY RZ SCL RMS WRMS LaRMS RMSc Days
----------------------------------------------------------------------------
cod 60 0.00 0.02 0.01 -0.20 -0.10 -0.18 0.0 10 7 11 3.6 35
0.01 0.01 0.01 0.26 0.25 0.18 0.1
emr 27 0.01 -0.03 -0.01 0.27 -0.09 0.04 -0.1 11 10 14 1.1 35
0.01 0.01 0.01 0.40 0.35 0.16 0.1
esa 46 0.01 -0.03 -0.03 0.11 0.19 0.19 0.0 14 13 14 2.8 35
0.01 0.01 0.01 0.27 0.44 0.42 0.2
gfz 46 -0.03 -0.02 -0.01 -0.19 -0.04 -0.15 -0.2 12 11 14 6120.6 35
0.01 0.01 0.01 0.23 0.17 0.15 0.1
jpl 37 0.01 0.03 0.00 -0.46 -0.02 0.04 0.1 8 8 8 1.0 35
0.01 0.01 0.01 0.26 0.25 0.13 0.1
ngs 45 0.01 -0.02 0.01 -0.23 0.27 0.18 0.0 15 13 16 24693.3 35
0.01 0.01 0.01 0.39 0.32 0.23 0.2
sio 76 -0.01 0.02 0.01 -0.19 -0.03 -0.15 0.2 10 9 15 0.0 35
0.01 0.02 0.01 0.38 0.30 0.81 0.1
Units: m - DX, DY, DZ
mas - RX,RY,RZ
ppb - SCL
cm - RMS, WRMS, LaRMS (Long arc orbit RMS)
ns - RMSc (sv clock)
The following table shows the average statistics of the Final orbit/clock
combination for the current year (Wks 0782-0820).
Start: 95 Jan 01 / wk782
End: 95 Dec 02 / wk829
STA DX DY DZ RX RY RZ SCL RMS WRMS LaRMS RMSc Days
----------------------------------------------------------------------------
cod 56 0.00 0.02 0.00 -0.41 -0.06 0.02 0.0 10 8 11 3876.3 336
0.01 0.02 0.01 0.24 0.30 0.21 0.1
emr 26 0.01 -0.02 0.00 -0.06 -0.08 0.12 -0.1 10 10 14 1.0 336
0.01 0.01 0.01 0.38 0.32 0.19 0.2
esa 40 0.00 -0.01 -0.03 0.31 0.15 -0.02 0.1 407 15 18 26.0 336
0.01 0.01 0.01 0.42 0.40 0.36 0.2
gfz 44 -0.03 -0.01 0.00 -0.23 0.11 -0.21 -0.3 40 40 15 1975.6 336
0.01 0.01 0.01 0.19 0.25 0.18 0.1
jpl 34 0.01 0.04 0.00 -0.49 0.04 0.11 0.1 9 9 10 0.9 336
0.01 0.01 0.01 0.25 0.28 0.15 0.1
ngs 39 0.01 -0.02 -0.01 -0.33 0.26 -0.03 0.3 19 18 20 13579.1 336
0.01 0.02 0.02 0.38 0.40 0.35 0.4
sio 52 0.01 -0.05 0.03 0.08 -0.16 -0.28 0.1 4094 2749 21 0.0 336
0.02 0.04 0.06 0.62 0.67 1.87 0.2
Units: m - DX, DY, DZ
mas - RX,RY,RZ
ppb - SCL
cm - RMS, WRMS, LaRMS (Long arc orbit RMS)
ns - RMSc (sv clock)
[Mailed From: Jan Kouba <kouba at geod.emr.ca>]
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