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Naval Meteorology and Oceanography Command U.S. Naval Observatory
Wednesday March 29, 2017

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USNO TRF Solution 2004a  

rotating earth

Global VLBI/TRF Solution 2004a
May 2004

rotating earth

Presented here is the U.S. Naval Observatory's 2004a global solution.   The Batch SOLVE solution used all available multi-baseline VLBI observations at 8.4 GHz (X-band) and 2.2 GHz (S-band) from 3 August, 1979 through 29 April, 2004.   This included a total of 3132 diurnal sessions and 3,728,091 measurements of group delay.   The BATCH control file 2004a.cnt along with databases given in 2004a.arc were used to generate this solution. The output spool file is 2004a.spl.gz. Plotted and tabulated below are the global and session RMS values for the solution.
 

Solution RMS delay and rate 
( postscript , pdf

RMS data file:  2004a.rms


 

Earth Orientation Parameters

The Earth Orientation parameters:  X and Y pole positions and rates, UT1 angle and rate, and daily offsets in the nutation in longitude and obliquity were estimated for each session separately.  Plotted and tabulated below are these data.
 
Pole Position X vs. Y:  Jan. 1995 to April 2003 ( postscript , pdf
Full EOP time series:  X pole, Ypole, UT angle ( postscript , pdf
Full Nutation offset time series:  Longitude and Obliquity  ( postscript , pdf

 

Tabulated data.

EOP time series Solve format 2004a.eop format description
EOP time series IVS format 2004a.eops format description
Correlations between EOP estimates 2004a.crl format description

 

Station and Source Positions

Positions of 573 sources were estimated as global parameters. Sources which participated in 2 or more sessions, had 40 or more good observations, and normalized residual delays less than 1.3 in the CRF2004a solution qualified for the list of global sources. Positions for an additional 144 sources were estimated for each session independently as local parameters. A total of 39 sources were eliminated due to bad data or insufficient number of observations. Positions and velocites for 112 stations were estimated as global parameters.
 
 

Tabulated data.

Station positions 2004a.sta format description
Station velocities 2004a.vel format description
Source positions 2004a.sou format description
Source position time series 2004a.lso format description

Comparisons


Shown below is a comparison of the USNO 2004a solution with the IERS C04 time series.  A weighted least-squares fit to the difference plots and the weighted rms are shown on each plot.
 

USNO - IERS (1979-2004) USNO - IERS (2000-2004)
Pole Position  ( postscript pdf ) Pole Position  ( postscript pdf )
UT1 - UTC  ( postscript pdf ) UT1 - UTC  ( postscript pdf )
Nutation Offset  ( postscript pdf ) Nutation Offset  ( postscript pdf )

 

Shown below is a comparison of the USNO 2004a solution with the GSFC 2004b solution.  A weighted least-squares fit to the difference plots and the weighted rms are shown on each plot.
 

USNO - GSFC (1979-2004) USNO - GSFC (2000-2004)
Pole Position  ( postscript pdf ) Pole Position  ( postscript pdf )
UT1 - UTC  ( postscript pdf ) UT1 - UTC  ( postscript pdf )
Nutation Offset  ( postscript pdf ) Nutation Offset  ( postscript pdf )


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