Author: IERS Rapid Service/Prediction Center
Subject: Earth Orientation Contributions to IERS Bulletin A
Date: 14 Sep 17


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://www.usno.navy.mil/USNO/earth-orientation/
eo-info/general. 

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 the ITRF and the ICRF reference frames by removing
a priori mean bias and rate.

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

GSI Int.     58006.33    10              -0.019               0.023

GSFC Int.    58009.79    31               0.005               0.018

USNO Int.    58009.79    32               0.000               0.019

IAA VLBI     57987.21     9   0.20  0.15 -0.004   0.14  0.28  0.012

GSFC VLBI    57994.21     9   0.10 -0.10 -0.002   0.07  0.05  0.004

USNO VLBI    57994.21     9   0.03 -0.08 -0.001   0.06  0.05  0.004

IVS  VLBI    57987.21     9   0.08 -0.14  0.002   0.13  0.20  0.004

ILRS SLR     57916.50    30  -0.11  0.10          0.12  0.11

IAA SLR      58008.69    30  -0.03  0.00          0.17  0.18

MCC SLR      58005.00    29   0.19  0.17          0.09  0.13

IGS Final    57991.50    30   0.00  0.00          0.01  0.01

IGS Rapid    58009.50    18   0.00  0.00          0.03  0.03

             ---        ---               ---                 ---

IGS Ultra    58010.00     2   0.00 -0.01          0.00  0.03

             58010.00     1              -0.003                 ---

USNO GPS     58010.25    32               0.014*              0.060*

NCEP AAM     58017.50    15              -0.001               0.006

* 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 table shows comparisons for other related time series during
the last 30 days.  No systematic corrections have been applied.

Units: milliseconds of arc for x, y; milliseconds of time for UT, LOD 

              Latest   #              Mean                Standard Deviation
Series         Day               (series-BullA)
                             x     y     UT     LOD     x     y      UT    LOD 

IGS Final    57991.5  30   0.01 -0.04  0.002*-0.001*  0.02  0.03  0.015* 0.019*

IGS Rapid    58008.5  30   0.02 -0.06  0.010*-0.001*  0.03  0.03  0.052* 0.023*

IGS Ultra    58009.25 120  0.02 -0.05  0.013*-0.001*  0.04  0.04  0.056* 0.028*

Bulletin B   57966.0  30  -0.01 -0.01  0.016          0.05  0.04  0.023

14C04        57980.0  30  -0.01 -0.02  0.014          0.05  0.04  0.027


Plots of the residuals are available at http://www.usno.navy.mil/USNO/
earth-orientation/eo-products/weekly.
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The IERS Rapid Service/Prediction Center is an activity of the Earth
Orientation Department at the U.S. Naval Observatory.