Author: IERS Rapid Service/Prediction Center
Subject: Earth Orientation Contributions to IERS Bulletin A
Date: 11 Aug 22


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.     59798.33    10               0.013               0.005

GSFC Int.    59801.79    25               0.009               0.010

USNO Int.    59801.79    24              -0.007               0.008

IAA VLBI     59782.27     9   0.18  0.39 -0.003   0.15  0.21  0.010

GSFC VLBI    59789.27     9  -0.09  0.10  0.003   0.07  0.04  0.004

USNO VLBI    59789.27     8  -0.05  0.09 -0.004   0.10  0.03  0.003

IVS  VLBI    59782.29     9  -0.03  0.26  0.004   0.10  0.12  0.003

ILRS SLR     59800.50    30  -0.12  0.21          0.12  0.12

IAA SLR      59800.54    31  -0.23  0.08          0.19  0.22

MCC SLR      59777.00    24   0.02  0.28          0.14  0.20

IGS Final    59783.50    30   0.00  0.00          0.01  0.01

IGS Rapid    59801.50    18   0.00  0.00          0.03  0.02

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

IGS Ultra    59802.00     2   0.00  0.00          0.05  0.02

             59802.00     1              -0.007                 ---

USNO GPS     59800.25    32               0.001*              0.072*

NCEP AAM     59809.50    15               0.001               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    59783.5  30   0.00  0.00  0.005*-0.002*  0.01  0.01  0.020* 0.018*

IGS Rapid    59800.5  30   0.00  0.00 -0.001*-0.003*  0.03  0.03  0.052* 0.017*

IGS Ultra    59801.25 120  0.00  0.01 -0.001*-0.005*  0.05  0.04  0.069* 0.032*

Bulletin B   59761.0  30  -0.01  0.02 -0.010          0.03  0.03  0.018

14C04        59772.0  30   0.00  0.02 -0.009          0.04  0.02  0.014


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.