[IGSREPORT-4441] Wk 0937 GPS Earth Orientation

[Dennis]

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IGS Electronic Report    Wed Dec 24  8:46:24 PST 1997      Message Number 4441
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Author: Dennis McCarthy
Subject: Wk 0937 GPS Earth Orientation

From: Dennis McCarthy
Subject: Earth Orientation Contributions to IERS Bulletin A
Date: 24 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.    50798.64    21                .008                .026

NEOS VLBI    50799.25     5    .05   .01   .002    .11   .04   .004

JPL VLBI     50721.86     8               -.005                .127

CSR SLR      50804.41    11   -.14  -.01  -.048    .36   .29   .081

IAA SLR      50804.00    30    .15  -.16           .32   .21

IGS Final    50795.50    30    .00   .02           .07   .05

IGS Rapid    50804.50     9   -.06   .03           .24   .23

             50804.50     6                .009                .018

USNO GPS     50804.50    30                .118                .059

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           50783.5    30   -.56  -.10           .29   .19

CODE          50791.5    30   -.44   .25 -15.49    .06   .10    .18

JPL           50795.5    30   -.10  -.24   4.64    .12   .16    .33

ESOC          50793.5    30   -.03  -.33           .27   .30

NRCan         50795.5    30   -.18  -.68  11.14    .18   .23    .14

GFZ           50795.5    30   -.30  -.09    .08    .14   .16    .11

NOAA          50803.5    30   -.60  -.78           .24   .29

USNO          50800.5    30   -.01  -.55           .26   .25

USNO GPS UT1  50804.5    30                 .12                 .06

IGS Final     50795.5    30   -.30  -.15    .01    .09   .06    .02

IGS Rapid     50804.5    30   -.44  -.40   -.04    .29   .31    .07

IERS Central Bureau Series:

Bulletin B    50754.     30   -.02  -.03   .009    .13   .16   .032

97C04         50805.     30   -.10  -.14  -.026    .18   .15   .080


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>]