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May 20, 2019

USNO TRF/EOP Solution 2008a

Global VLBI TRF/EOP
Solution 2008a
February 2008


Presented here is the U.S. Naval Observatory's 2008a global
solution. The Batch SOLVE solution used all available
multibaseline VLBI observations at 8.4 GHz (Xband) and 2.2 GHz
(Sband) from 1979 August 3 through 2008 January 31. This
included a total of 3708 diurnal sessions and 5,160,648
measurements of group delay. The BATCH control
file
2008a.cnt along with databases given in
2008a.arc were used to generate this solution. The output spool
file is
2008a.spl.gz. Plotted and tabulated below are the global and
session RMS values for the solution.
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. 2000
to Jan. 31 2008 (
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.
Station and Source Positions
Positions of 612 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
qualified for the list of global sources. Positions for an additional
290 sources were estimated for each session independently as
local parameters. A total of 127 sources were eliminated
due to bad data or insufficient number (<3) of observations.
Positions and velocites for 128 stations were estimated as
global parameters.
Tabulated data.
Comparisons
Shown below is a comparison of the USNO 2008a solution with
the
IERS C04_05 time series. A weighted leastsquares fit
to the difference plots and the weighted rms are shown on each plot.
Shown below is a comparison of the USNO 2008a solution with
the GSFC 2007c solution. A weighted leastsquares fit to
the difference plots and the weighted rms are shown on each plot.
Shown below is a comparison of the USNO 2008a solution with
the previous USNO 2007c solution. A weighted leastsquares fit to
the difference plots and the weighted rms are shown on each plot.
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