Global VLBI EOP-S Solution 2008b
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USNO Global VLBI TRF/EOP Solution 2008bJuly 2008
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Presented here is the U.S. Naval Observatory's 2008b global VLBI EOP-S
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 1979 August 3 through 2008 June 23. This
included a total of 3763 diurnal sessions and 5,317,776
measurements of group delay. The BATCH control
file
2008b.cnt along with databases given in
2008b.arc were used to generate this solution. The output spool
file is
2008b.spl.gz. Plotted and tabulated below are the global and
session RMS values for the solution.
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Solution RMS delay and rate ( postscript , pdf ) Solution RMS histograms ( postscript , pdf ) RMS data file: 2008b.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. 2000 to June 23 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 EOP data.
| EOP time series Solve format | 2008b.eop | format description |
| EOP time series IVS format | 2008b.eops | format description |
| Correlations between EOP estimates | 2008b.crl | format description |
Station and Source Positions
Positions of 616 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 339 sources were estimated for each session independently as local parameters. A total of 138 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 station and source data.
| Station positions | 2008b.sta | format description |
| Station velocities | 2008b.vel | format description |
| Source positions | 2008b.sou | format description |
| Source position time series | 2008b.lso | format description |
Solution Comparisons
Shown below is a comparison of the USNO 2008b solution with
the
IERS C04_05 time series. A weighted least-squares fit
to the difference plots and the weighted rms are shown on each plot.
| USNO - IERS C04_05 (1979-2008) | USNO - IERS C04_05 (2000-2008) |
|---|---|
| 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 2008b solution with
the GSFC 2008a solution. A weighted least-squares fit to
the difference plots and the weighted rms are shown on each plot.
| USNO - GSFC (1979-2008) | USNO - GSFC (2000-2008) |
|---|---|
| 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 2008b solution with
the previous USNO 2008a solution. A weighted
least-squares fit to
the difference plots and the weighted rms are shown on each plot.
| 2008b - 2008a (1979-2008) | 2008b - 2008a (2000-2008) |
|---|---|
| Pole Position ( postscript , pdf ) | Pole Position ( postscript , pdf ) |
| UT1 - UTC ( postscript , pdf ) | UT1 - UTC ( postscript , pdf ) |
| Nutation Offset ( postscript , pdf ) | Nutation Offset ( postscript , pdf ) |
