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Global VLBI EOP-I Solution 2008a

 

 

Presented here is the U.S. Naval Observatory's i2008a analysis of 1.5 hr dual-frequency VLBI sessions carried out under the auspices of the International VLBI Service (IVS) Intensive Program. UT1 angles are determined for most sessions between 2000 July 06 and 2008 February 18 using dual-frequency observations obtained at 8.4 GHz (X-band) and 2.2 GHz (S-band).

The SOLVE batch control file int2008a.cnt was used to generate a least-squares solution with an output spool file int2008a.spl.gz. Note that this solution uses Calc10 (see calc10.ps). Tabulated below are the session values from this solution.

 

Earth Orientation Parameters

UT1 angle is determined for each session separately.

EOP time series, Solve format int2008a.eop format description
EOP time series, EOB format int2008a.eob format description
EOP time series, IVS format int2008a.eopi format description

 

Comparisons

Differences of the i2008a UT1 angles with the IERS 05 C 04 UT1 angles.

Plot of i2008a minus IERS 05 C04 PS JPG
   Linear Regression: bias =  4.1 +/- 0.5 micro-seconds at J2000
   Linear Regression: rate = -1.4 +/- 0.2 nano-seconds/day

   Residuals: w.r.m.s. = 14.1 micro-seconds
   Residuals: chi2/ndg =  2.77

Differences of the i2008a UT1 angles with the GSFC int22 UT1 angles.

Plot of i2008a minus gsfint22 PS JPG
   Linear Regression: bias = -0.3 +/- 0.8 micro-seconds at J2000
   Linear Regression: rate = -0.4 +/- 0.4 nano-seconds/day

   Residuals: w.r.m.s. = 7.3 micro-seconds
   Residuals: chi2/ndg = 0.33

Differences of the i2008a UT1 angles with the i2007c UT1 angles.

Plot of i2008a minus i2007c PS JPG
   Linear Regression: bias = -0.4 +/- 0.7 micro-seconds at J2000
   Linear Regression: rate = -0.1 +/- 0.3 nano-seconds/day

   Residuals: w.r.m.s. = 3.9 micro-seconds
   Residuals: chi2/ndg = 0.10
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