[IGSREPORT-4456] Wk 0938 GPS Earth Orientation

[Dennis]

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IGS Electronic Report    Wed Dec 31 10:02:28 PST 1997      Message Number 4456
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Author: Dennis McCarthy
Subject: Wk 0938 GPS Earth Orientation

From: Dennis McCarthy
Subject: Earth Orientation Contributions to IERS Bulletin A
Date: 31 Dec 97


An updated look at Earth orientation data submitted to the IERS
follows.  All data are aligned to the system defined by ITRF94 and
the current ICRF by estimating and removing mean bias, rate, annual
and semiannual terms.  The only exception to this is the NEOS VLBI
and the NEOS Intensives series whose UT1-UTC are not corrected.

Below are the mean and standard deviation of each submission
included in the Rapid Service combination compared with the
combination for the last 30 days.  Units are milliseconds of arc
for x and y, and milliseconds of time for UT1-UTC.

Contributor   Latest      #         Mean          Standard Deviation
               Day               (NEOS-series)
                                x     y  UT1-UTC    x     y  UT1-UTC

NEOS Int.    50809.78    23                .000                .019

NEOS VLBI    50799.25     5    .05   .00   .001    .09   .04   .003

JPL VLBI     50721.86     8               -.005                .127

CSR SLR      50804.41    11   -.17  -.03  -.038    .36   .29   .062

IAA SLR      50810.00    30    .06  -.13           .22   .19

IGS Final    50802.50    30    .01   .00           .08   .04

IGS Rapid    50811.50     9    .04   .10           .11   .14

             50811.50     2               -.035                .023

USNO GPS     50811.50    30                .123                .046

For comparison, the mean and standard deviations of other related
series are listed below for the last 30 days.  Units are milliseconds
of arc for x and y, and milliseconds of time for UT1-UTC

Series        Latest      #         Mean          Standard Deviation
               Day               (NEOS-series)
                                x     y  UT1-UTC    x     y  UT1-UTC

SIO           50802.5    30   -.58  -.06           .30   .18

CODE          50807.5    30   -.39   .32 -15.27    .06   .19    .09

JPL           50802.5    30   -.10  -.28   4.81    .14   .12    .25

ESOC          50802.5    30   -.13  -.37           .48   .30

NRCan         50802.5    30   -.24  -.77  11.23    .22   .18    .17

GFZ           50802.5    30   -.30  -.02    .02    .17   .16    .11

NOAA          50807.5    30   -.64  -.79           .26   .31

USNO          50807.5    30   -.04  -.56           .24   .24

USNO GPS UT1  50811.5    30                 .12                 .05

IGS Final     50802.5    30   -.30  -.16    .00    .11   .06    .02

IGS Rapid     50811.5    30   -.42  -.37   -.03    .31   .33    .09

IERS Central Bureau Series:

Bulletin B    50754.     30   -.02  -.03   .007    .14   .16   .033

97C04         50812.     30   -.18  -.16  -.026    .19   .11   .064


Plots of the residuals are available through the world wide web at,
http://maia.usno.navy.mil/plots.html to anyone interested.
--
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>]