[IGSREPORT-3721] Wk 0904B Earth Orientation

[Dennis]

******************************************************************************
IGS Electronic Report    Thu May  8 10:58:05 PDT 1997      Message Number 3721
******************************************************************************

Author: Dennis McCarthy
Subject: Wk 0904B Earth Orientation

From:     Dennis McCarthy
Subject:  Earth Orientation Contributions to IERS Bulletin A
Date:     8 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             (series-NEOS)
                              x     y   UT1-UTC    x     y  UT1-UTC

NEOS Int.    50573.76   23               0.003               0.034

NEOS VLBI    50568.25    5  -0.03  0.08 -0.004   0.13  0.10  0.011

JPL VLBI     50573.29    9               0.084               0.121

CSR SLR      50573.54   10  -0.06  0.07  0.005   0.26  0.25  0.066

TUD SLR      50547      10  -0.15  0.18          0.58  0.20

IAA SLR      50574      30   0.25 -0.13          0.28  0.28

UT LLR       50567.48   11              -0.083               0.273

GPS Comb.*   50574.5    30  -0.02  0.00          0.10  0.13

             50574.5     1              -0.129               0.000

     * GPS series is a combination of results from IGS Analysis
     Centers (see below) and USNO.

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      50564.5    30  -0.10 -0.19          0.11  0.14

CODE         50570.5    30  -0.39  0.01 -18.25   0.08  0.11  0.08

JPL          50564.5    30  -0.20 -0.16  -3.87   0.18  0.28  0.17

ESOC         50564.5    30  -0.23 -0.28          0.17  0.24

NRCan        50571.5    30   0.00 -0.33  10.17   0.25  0.24  0.07

GFZ          50564.5    30  -0.30 -0.27          0.15  0.17

NOAA         50572.5    30  -0.71 -0.60          0.91  0.74

USNO         50574.5    30  -0.23 -0.59          0.38  0.28

IGS Final    50564.5    30  -0.26 -0.19  -0.04   0.08  0.12  0.04

IGS Rapid    50574.5    30  -0.30 -0.16  -0.03   0.27  0.20  0.21


IERS Central Bureau Series:

Bulletin B   50539      30   0.07  0.09 -0.008   0.12  0.09  0.025

97c04        50575      30  -0.15  0.08 -0.023   0.38  0.12  0.021


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>]