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[IGSREPORT-6228] Wk 1016 GPS Earth Orientation
- Subject: [IGSREPORT-6228] Wk 1016 GPS Earth Orientation
- From: IERS Sub-bureau for Rapid Service and Predictions
- Date: Thu, 1 Jul 1999 11:21:28 PDT
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IGS Electronic Report Thu Jul 1 11:21:28 PDT 1999 Message Number 6228
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Author: IERS Sub-bureau for Rapid Service and Predictions
Subject: Wk 1016 GPS Earth Orientation
Subject: Earth Orientation Contributions to IERS Bulletin A
Date: 1 Jul 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. 51357.61 27 -.002 .021
SPbU Int. 51353.62 23 .014 .020
NEOS VLBI 51352.22 5 -.22 .07 -.003 .08 .21 .006
CSR SLR 51342.06 11 -.15 -.11 -.021* .35 .24 .068*
TUD SLR 51354.00 10 -.31 .10 .36 .39
IAA SLR 51358.00 30 -.03 .03 .19 .25
MCC SLR 51352.00 30 .10 -.03 .16 .19
UTX LLR 51324.88 9 .061 .238
IGS Final 51348.50 30 .01 .00 .03 .03
IGS Rapid 51359.50 11 .01 -.01 .06 .07
51359.50 2 -.003* .004*
USNO GPS 51359.50 30 -.003* .014*
EMR GPS 51359.50 22 .016* .028*
* 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 51355.5 30 .27 .12 2.27 .008 .06 .07 .05 .014
ESA 51341.5 30 .48 .16 -.004 .09 .10 .020
EMR 51355.5 30 .20 .11 -16.59 .003 .13 .13 .19 .025
GFZ 51355.5 30 .21 .04 -.03 .006 .10 .08 .08 .019
JPL 51348.5 30 .32 .02 -14.60 .027 .08 .06 .24 .016
NGS 51354.5 30 .41 -.19 -.003 .14 .14 .026
SIO 51348.5 30 .43 .14 .001 .09 .12 .023
USN (Rapid) 51355.5 29 .32 .13 .003 .13 .13 .027
USNO GPS UT 51359.5 30 1.14 .02
IGS Final 51348.5 30 .30 .07 .00 .003 .05 .05 .01 .014
IGS Rapid 51359.5 30 .33 .09 -.02 .004 .12 .11 .06 .018
* 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 51299. 30 -.02 .07 -.002 .05 .05 .015
97C04 51358. 30 -.05 .16 -.127 .06 .09 .454
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 @ 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 @ maia.usno.navy.mil>]