Author: IERS Rapid Service/Prediction Center
Subject: Earth Orientation Contributions to IERS Bulletin A
Date: 10 Aug 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.     57971.33    10              -0.011               0.025

GSFC Int.    57974.79    24               0.010               0.026

USNO Int.    57972.31    26               0.003               0.023

IAA VLBI     57955.27     9   0.19  0.07 -0.012   0.14  0.18  0.002

GSFC VLBI    57955.27     9   0.13 -0.09 -0.004   0.05  0.10  0.005

USNO VLBI    57955.27     9   0.03 -0.05 -0.002   0.05  0.08  0.004

IVS  VLBI    57953.21     9   0.19 -0.07  0.004   0.05  0.10  0.003

ILRS SLR     57916.50    30  -0.11  0.10          0.12  0.11

IAA SLR      57973.60    27  -0.04  0.11          0.20  0.18

MCC SLR      57970.00    25   0.15  0.21          0.15  0.10

IGS Final    57956.50    30   0.00  0.00          0.01  0.01

IGS Rapid    57974.50    18   0.00  0.00          0.02  0.02

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

IGS Ultra    57975.00     2   0.01  0.00          0.03  0.02

             57975.00     1               0.002                 ---

USNO GPS     57975.25    32              -0.007*              0.020*

NCEP AAM     57982.50    15               0.000               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    57956.5  30   0.01 -0.04 -0.002*-0.002*  0.02  0.02  0.014* 0.015*

IGS Rapid    57973.5  30   0.02 -0.06  0.016*-0.003*  0.03  0.03  0.047* 0.015*

IGS Ultra    57974.25 120  0.01 -0.05  0.011* 0.000*  0.04  0.03  0.047* 0.024*

Bulletin B   57935.0  30  -0.01 -0.01  0.008          0.05  0.03  0.030

14C04        57945.0  30  -0.01 -0.01  0.020          0.05  0.03  0.026


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.