Technical description of solution gsiINT2a Intensive series UT1 solution 2012-Feb-11.

 1.  Purpose of solution: Ultra-rapid determination of UT1 from IVS INT2 sessions 

 2   Analysis Center:  Geospatial Information Authority of Japan (GSI)

 3.  Short narrative description of solution:
     Intensive solution gsiINT2a is for the ultra-rapid estimation of UT1 from the IVS-INT2
     sessions. Most sessions consist of about 40 observations on one baseline. The solution
     includes all usable INT2 sessions from 2002.09.05 through 2012.12.31.
     The rapid solutions of INT2 is submitted within 1 hour after the observing session.
     The processing has been made in automated analysis mode (including ambiguity resolution) 
     whereas observations were extracted directly from the correlator output. The processing 
     software c5++ is following the IERS Conv. 2003 and has been validated within the 
     "Comparison Campaign of VLBI Data Analysis Software" (Plank et al., 2010).  
     All parameters are estimated by a least-squares estimation using a Gauss-Markov model. 
     Outliers were detected and removed by a simple 3-sigma criteria before re-iterating the process. 
     For ultra-rapid solutions, forecast values of Xp/Yp resp. 
     Mapping function coefficients for VMF are used.

 4.  Estimated parameters:

     a. celestial frame:  No

     b. terrestrial frame:  No

     c. Earth orientation:  UT1-UTC

     d. zenith troposphere:  One zenith wet delay offset per station

     e. troposphere gradient:  No

     f. station clocks:  Offset and rate

     g. baseline clocks:  No

     h. other:  No

 5.  Celestial reference frame:

     a. a priori source positions:  ICRF2

     b. source positions adjusted in solution:  No

     c. solution identification or reference:  ICRF2

 6 - Terrestrial reference frame:

     a. a priori station positions:  VTRF2008
                                     The TSUKUB32 position is the value which used
                                     the dXYZ value and was changed into VTRF coordinates. 
				     the dXYZ value : TSUKUB32_dXYZ_dUEN by D.MacMillan

     b. a priori station velocities:  VTRF2008 velocity field

     c. reference epoch:  2000.0

     d. station positions/velocities adjusted in solution:  No

     l. solution identification or reference:  VTRF2008

 7.  Earth orientation:

     a. a priori precession model:  IERS Conventions 2003

     b. a priori nutation model: IERS Conventions 2003

     c. a priori short-period tidal variations in x, y, UT1:  IERS Conventions 2003

     d. EOP estimation:  one UT1-UTC estimate per session, 
                         reference epoch in the middle of the session

 8.  A priori geophysical models:

     a. troposphere: VMF for dry and wet delays

     b. solid Earth tide:  IERS Conventions 2003

     c. ocean loading:  IERS Conventions 2003

     d. atmosphere loading: not applied

 9.  Data type:  delays from correlator output (K5)

 10. Data editing:  Automatic ambiguity resolution after Hobiger et al. (2011) 
                    using X/S band data only when both quality flags show no errors. 
                    Meteo data and cable cal is automatically extracted from the log files.

 11. Data weighting: Observations are weighted by their wet mapping function values.

 12. Standard errors reported: Formal errors at the one sigma level are derived from 
                               least squares adjustment

 13  Software:  c5++ (beta version) 

 14. Other information:  
     
     References
     
     1. Hobiger T., Otsubo T., Sekido M., Gotoh T., Kubooka T. Takiguchi H. (2011), 
         "Fully automated VLBI analysis with c5++ for ultra-rapid determination of UT1", 
          Earth, Planets, Space, 2011.

     2. L. Plank, J. Boehm, H. Schuh (2010), "Comparison Campaign of VLBI Data Analysis 
          Software - First Results"; presented at the IVS GM 2010, Hobart, AUS.

------------------------------------------------------------------------------
Kensuke Kokado, Chief of Baseline Analysis Sec., Space Geodesy Div., Geodetic Dept., 
Tel:	+81-29-864-4806
Fax:	+81-29-864-1802
Mail:	vlbi@gsi.go.jp

Geospatial Information Authority of Japan.
Kitasato-1 Tsukuba Ibaraki 305-0811 JAPAN