Author: IERS Rapid Service/Prediction Center
Subject: Earth Orientation Contributions to IERS Bulletin A
Date:  9 Feb 12


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.     55955.33     9              -0.006               0.012

GSFC Int.    55964.79    31              -0.001               0.017

USNO Int.    55965.79    19               0.004               0.015

IAA VLBI     55950.21     9   0.19 -0.13 -0.009   0.26  0.17  0.006

GSFC VLBI    55953.27     9  -0.01 -0.17  0.006   0.12  0.21  0.008

USNO VLBI    55953.27     9   0.01 -0.01  0.002   0.20  0.17  0.009

IVS  VLBI    55953.27     9   0.14 -0.18  0.003   0.10  0.11  0.007

ILRS SLR     55961.50    30   0.10  0.07          0.19  0.18

IAA SLR      55964.55    30   0.11 -0.05          0.13  0.14

MCC SLR      55961.00    27  -0.01  0.24          0.14  0.15

IGS Final    55954.50    30   0.00  0.00          0.01  0.01

IGS Rapid    55965.50    11   0.00 -0.01          0.03  0.02

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

IGS Ultra    55966.00     2   0.01  0.02          0.01  0.01

             55966.00     1               0.000                 ---

USNO GPS     55965.75    32              -0.001*              0.015*

NCEP AAM     55973.50    15               0.000               0.002

* 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    55954.5  30  -0.01  0.02  0.001* 0.000*  0.03  0.04  0.012* 0.015*

IGS Rapid    55964.5  30   0.01  0.00 -0.010* 0.003*  0.04  0.04  0.027* 0.014*

IGS Ultra    55965.25 120  0.01  0.00 -0.005* 0.005*  0.05  0.04  0.035* 0.040*

Bulletin B   55927.0  30   0.00  0.00  0.003          0.04  0.03  0.007

08C04        55936.0  30   0.00  0.00  0.003          0.04  0.03  0.006


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.