[IGSREPORT-6021] Wk 1007 GPS Earth Orientation
IERS
IERS
Fri Apr 30 12:34:09 PDT 1999
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IGS Electronic Report Fri Apr 30 12:34:09 PDT 1999 Message Number 6021
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Author: IERS Sub-bureau for Rapid Service and Predictions
Subject: Wk 1007 GPS Earth Orientation
Subject: Earth Orientation Contributions to IERS Bulletin A
Date: 29 Apr 99
In this report, individual Earth orientation time series are compared
to the IERS Bulletin A combination. For further information, including
the raw time series, refer to http://maia.usno.navy.mil/bulletin-a.html.
The first table below shows some comparison results for those series
included in Bulletin A during the last 30 days. All data are aligned to
the system defined by ITRF94 and the current ICRF by removing a priori mean
bias, rate, annual and semiannual terms. (No corrections are applied to
the NEOS VLBI and the NEOS Intensives series for UT1-UTC.)
Units: milliseconds of arc for x, y; milliseconds of time for UT1-UTC
Contributor Latest # Mean Standard Deviation
Series Day (series-BullA)
x y UT1-UTC x y UT1-UTC
NEOS Int. 51294.62 25 .005 .016
SPbU Int. 51290.63 21 .005 .016
NEOS VLBI 51289.25 5 -.14 .03 -.004 .06 .04 .004
CSR SLR 51282.07 10 -.06 -.20 -.008* .27 .35 .081*
TUD SLR 51291.00 10 -.38 -.14 .18 .43
IAA SLR 51295.00 30 -.05 -.10 .19 .25
MCC SLR 51289.00 30 -.09 -.12 .18 .17
UTX LLR 51237.27 9 -.063 .388
IGS Final 51285.50 30 .01 .01 .02 .01
IGS Rapid 51296.50 11 .02 -.01 .05 .02
51296.50 2 .002* .006*
USNO GPS 51296.50 22 .002* .017*
EMR GPS 51296.50 22 -.013* .057*
* All satellite techniques provide information on the rate of change of
Universal Time contaminated by effects due to unmodelled orbit node
motion. VLBI-based results have been used to minimize drifts in UT
estimates.
The following tables show comparisons for other related time series during
the last 30 days. All IGS series are final solutions except for the USNO
series. No a priori systematic corrections have been applied.
Units: milliseconds of arc for x, y; milliseconds of time for UT, LOD
IGS Latest # Mean Standard Deviation
Series Day (series-BullA)
x y UT* LOD* x y UT* LOD*
COD 51292.5 30 .29 .10 2.74 .015 .09 .07 .13 .013
ESA 51285.5 30 .30 .17 -.026 .15 .16 .032
EMR 51285.5 30 .21 .21 -16.51 .006 .19 .16 .05 .028
GFZ 51292.5 30 .32 -.01 -.17 .020 .09 .10 .28 .029
JPL 51285.5 30 .30 .00 -13.81 .004 .11 .09 .06 .029
NGS 51292.5 30 .41 -.11 -.028 .17 .18 .049
SIO 51285.5 30 .35 .18 .015 .14 .08 .030
USN (Rapid) 51296.5 30 .36 .09 -.013 .16 .15 .032
USNO GPS UT 51296.5 30 .95 .05
IGS Final 51285.5 30 .32 .09 .01 -.005 .07 .05 .02 .022
IGS Rapid 51296.5 30 .30 .04 -.01 .007 .12 .09 .08 .023
* All satellite techniques provide information on the rate of change of
Universal Time contaminated by effects due to unmodelled orbit node
motion. The UT results for COD and JPL are integrations of LOD estimates.
EMR estimates UT and LOD separately by applying a priori orbit constraints.
GFZ and IGS use VLBI-based results to minimize drifts in their UT estimates
and thus the standard deviations are not representative of the intrinsic
capabilities of GPS alone for monitoring UT variations. USNO estimates
UT using long-term models for orbit plane rotations.
IERS Central Bureau Series:
Series Latest # Mean Standard Deviation
Day (series-BullA)
x y UT1-UTC x y UT1-UTC
Bulletin B 51239. 30 .03 .06 -.009 .06 .09 .019
97C04 51297. 30 -.02 .08 -.002 .24 .10 .015
Plots of the residuals are available at http://maia.usno.navy.mil/plots.html.
------------------------------------------------------------------------------
The IERS Sub-bureau for Rapid Service and Prediction is an activity of the
National Earth Orientation Service and is performed by the Earth Orientation
Department at the U.S. Naval Observatory.
--
Dennis D. McCarthy dmc at maia.usno.navy.mil
Director, Directorate of Time phone: (202) 762-1837
U.S. Naval Observatory fax: (202) 762-1563
Washington, DC 20392-5420
[Mailed From: Dennis McCarthy <dmc at maia.usno.navy.mil>]
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