Author: IERS Rapid Service/Prediction Center
Subject: Earth Orientation Contributions to IERS Bulletin A
Date: 10 Jul 25


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.     60862.33    10               0.016               0.018

GSFC Int.    60864.75    55              -0.005               0.026

USNO Int.    60864.75    53               0.012               0.021

IAA VLBI     60685.27     6  -0.07  0.19  0.000   0.26  0.15  0.005

GSFC VLBI    60850.21     9  -0.11 -0.07 -0.008   0.29  0.14  0.009

USNO VLBI    60850.21     9  -0.02 -0.03 -0.002   0.09  0.07  0.004

IVS  VLBI    60850.21     9   0.31  0.18  0.011   0.09  0.08  0.007

ILRS SLR     60864.50    29  -0.12 -0.14          0.13  0.14

IGS Final    60854.50    30   0.00  0.00          0.00  0.00

IGS Rapid    60865.50    11   0.00  0.00          0.01  0.01

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

IGS Ultra    60866.00     2   0.00 -0.01          0.01  0.01

             60866.00     5               0.000*              0.007*

USNO GPS     60498.00     9               0.058*              0.125*

NCEP AAM     60873.50    15               0.001               0.004

* 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    60854.5  30   0.00  0.00  0.003*-0.001*  0.00  0.00  0.023* 0.013*

IGS Rapid    60864.5  30   0.00  0.00  0.005*-0.001*  0.02  0.02  0.043* 0.017*

IGS Ultra    60865.25 120 -0.02  0.01  0.008*-0.007*  0.03  0.02  0.050* 0.047*

Bulletin B   60827.0  30   0.02  0.00  0.008          0.04  0.05  0.014

C04          60836.0  30   0.03  0.00  0.007          0.04  0.05  0.015


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.