0 - Technical description of solution bkg2002b.trf

 1 - Technique:   VLBI

 2 - Analysis Centre:
     Federal Agency for Cartography and Geodesy (BKG)
     Karl-Rothe-Strasse 10-14
     D-04105 Leipzig, Germany
   
     and 
   
     Geodetic Institute of the University of Bonn (GIUB)
     Nussallee 17
     D-53115 Bonn, Germany
     
 3 - Software used:
     CALC 9.12, SOLVE release: 2002.03.06
     
 4 - Data span:
     Jan 1984 - Dec 2001

 5 - Celestial Reference Frame: icrf-Ext1 

     a - Nature:
     
         extragalactic

     b - Definition of the orientation:
         Constraining the sum of the RA and Dec adjustments of the radio source
	 positions for 211 defining sources of ICRF-Ext1
	 to be zero (no-net-rotation)

 6 - Terrestrial Reference Frame: itrf2000 and associated 
                                  itrf2000 velocity field 
                                  

     a - Relativity scale:
     
         Solar System Bary Center (SSB)

     b - Velocity of light:
     
         299792458 m/s

     c - Geogravitational constant:
     
         not applicable

     d - Permanent tidal correction:
     
         no  
         
     e - Definition of the origin:
     
         No net translation condition for 12 stations in the TRF
          DSS45     CODE: 1545
	  FORTLEZA  CODE: 7297
          GILCREEK  CODE: 7225
	  HARTRAO   CODE: 7232
	  HOBART26  CODE: 7242
	  KASHIMA   CODE: 1856
	  KOKEE     CODE: 7298
	  LA-VLBA   CODE: 7611
	  MK-VLBA   CODE: 7617
	  NRAO20    CODE: 7208
	  NYALES20  CODE: 7331
	  WETTZELL  CODE: 7224
	 i.e. sum over all translations of these stations w.r.t.
         TRF is zero.

     f - Definition of the orientation:
     
         No net rotation condition for 12 stations in the TRF
          DSS45     CODE: 1545
	  FORTLEZA  CODE: 7297
          GILCREEK  CODE: 7225
	  HARTRAO   CODE: 7232
	  HOBART26  CODE: 7242
	  KASHIMA   CODE: 1856
	  KOKEE     CODE: 7298
	  LA-VLBA   CODE: 7611
	  MK-VLBA   CODE: 7617
	  NRAO20    CODE: 7208
	  NYALES20  CODE: 7331
	  WETTZELL  CODE: 7224
	 i.e. sum over all rotations of these stations w.r.t. TRF is zero.


     g - Reference epoch:
     
         1997.0

     h - Tectonic plate model:
     
         None (TRF used as apriori)

     i - Constraints for time evolution:
     
         No net velocity adjustment condition in translation 
         and rotation for 5 stations in the TRF 
          DSS45     CODE: 1545
	  HOBART26  CODE: 7242
	  RICHMOND  CODE: 7219
          WESTFORD  CODE: 7209
	  WETTZELL  CODE: 7224
         i.e. sum over all velocities adjustments in translation  
         and rotation of these stations w.r.t. TRF is zero.
         

 7 - Earth orientation:

     a - A priori precession model:
     
         IERS 1996 
         
     b - A priori nutation model:
     
         IERS 1996 

     c - Short-period tidal variations in x, y, UT1:
     
         Model used according to:
         John Gipson, VLBI determiantion of neglected tidal terms in  
         high frequency Earth Orientation Variation.
         Journal of Geophysical Research, Vol. 101, No. B12, p. 28051 -28064,
         Dec 10, 1996.


 8 - Estimated Parameters:

     a - Celestial Frame:
     
         right ascension and declination of all sources
	 with a priori variance 1.E-6 rad

     b - Terrestrial Frame:
     
         x0, y0, z0, xdot, ydot, zdot

     c - Earth Orientation:
     
         xp, xpdot, yp, ypdot, UT1-UTC, UT1dot, dpsi, deps

     d - Others:
     
         - clock polynomials plus piece-wise linear functions,
	   with rate constraints of 5.E-14,
         - wet zenith tropospheric delays as 60 min piece-wise linear functions,
           with rate constraints of 50 psec/hr
         - troposphere gradients,
           offset constraint 0.5 mm, rate constraint 2.0 mm/day