[IGSREPORT-3730] Wk 0905 GPS Earth Orientation

[Dennis]

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IGS Electronic Report    Tue May 13 10:34:51 PDT 1997      Message Number 3730
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Author: Dennis McCarthy
Subject: Wk 0905 GPS Earth Orientation

From:     Dennis McCarthy
Subject:  Earth Orientation Contributions to IERS Bulletin A
Date:     13 May 1997


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
series whose UT1-UTC is not corrected.

Below are the mean and standard deviation of each submission compared
with the Rapid Service 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.    50576.75   22               0.006               0.029

NEOS VLBI    50575.08    5  -0.02  0.35  0.000   0.09  0.57  0.007

JPL VLBI     50573.29    9               0.107               0.122

CSR SLR      50573.54   10  -0.06  0.05  0.001   0.22  0.29  0.067

TUD SLR      50547      10  -0.13  0.13          0.60  0.22

IAA SLR      50579      30   0.37 -0.01          0.39  0.31

UT LLR       50567.48   11              -0.090               0.293

IGS Final    50571.5    30  -0.01 -0.04          0.06  0.10

IGS Rapid    50579.5     8  -0.10 -0.09          0.09  0.14

             50579.5     3              -0.078               0.020

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

Scripps      50571.5    30  -0.09 -0.12          0.11  0.10

CODE         50576.5    30  -0.39  0.01 -18.21   0.13  0.15  0.08

JPL          50571.5    30  -0.23 -0.11  -4.02   0.19  0.27  0.22

ESOC         50571.5    30  -0.27 -0.23          0.17  0.19

NRCan        50571.5    30  -0.04 -0.29  10.15   0.23  0.22  0.06

GFZ          50571.5    30  -0.29 -0.14          0.15  0.17

NOAA         50575.5    30  -0.67 -0.45          1.00  0.77

USNO         50576.5    30  -0.27 -0.54          0.32  0.26

IGS Final    50571.5    30  -0.28 -0.14  -0.06   0.08  0.10  0.04

IGS Rapid    50579.5    30  -0.35 -0.13  -0.06   0.21  0.19  0.21


IERS Central Bureau Series:

Bulletin B   50539      30   0.08  0.02  0.014   0.11  0.11  0.026

97c04        50579      30  -0.11  0.05  0.013   0.22  0.13  0.034


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>]