[IGSREPORT-5967] Wk 1005 GPS Earth Orientation
IERS
IERS
Thu Apr 15 11:38:03 PDT 1999
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IGS Electronic Report Thu Apr 15 11:38:03 PDT 1999 Message Number 5967
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Author: IERS Sub-bureau for Rapid Service and Predictions
Subject: Wk 1005 GPS Earth Orientation
Subject: Earth Orientation Contributions to IERS Bulletin A
Date: 15 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. 51280.66 24 .003 .013
SPbU Int. 51278.82 23 .005 .014
NEOS VLBI 51275.25 5 -.14 .05 -.002 .10 .03 .002
CSR SLR 51255.17 11 -.18 -.04 -.004* .32 .37 .072*
TUD SLR 51276.00 10 -.52 -.22 .35 .32
IAA SLR 51281.00 30 -.05 -.17 .19 .20
MCC SLR 51275.00 30 -.03 -.07 .15 .21
UTX LLR 51237.27 9 -.063 .388
IGS Final 51271.50 30 .01 .01 .02 .03
IGS Rapid 51282.50 11 .00 .00 .03 .03
51282.50 2 -.019* .008*
USNO GPS 51282.50 22 -.004* .015*
EMR GPS 51282.50 22 .008* .042*
* 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 51278.5 30 .31 .08 3.03 .024 .08 .09 .27 .017
ESA 51271.5 30 .30 .21 -.032 .13 .19 .030
EMR 51271.5 30 .13 .26 -16.52 .021 .15 .20 .06 .030
GFZ 51271.5 30 .32 .02 .05 -.010 .07 .09 .11 .030
JPL 51271.5 30 .34 .08 -13.73 .004 .12 .12 .07 .043
NGS 51278.5 30 .45 -.06 -.035 .18 .19 .044
SIO 51271.5 30 .34 .15 .013 .10 .11 .031
USN (Rapid) 51282.5 30 .31 .14 -.020 .16 .16 .028
USNO GPS UT 51282.5 30 .91 .02
IGS Final 51271.5 30 .32 .10 .01 -.007 .06 .06 .02 .023
IGS Rapid 51282.5 30 .30 .09 .05 -.004 .11 .12 .12 .030
* 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 .05 -.009 .06 .10 .019
97C04 51283. 30 .02 .11 .021 .13 .12 .084
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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