0 - Technical description of solution bkg2009a.trf

 1 - Technique:   VLBI

 2 - Analysis Centre:
     Federal Agency for Cartography and Geodesy (BKG)
     Karl-Rothe-Strasse 10-14
     D-04105 Leipzig, Germany
   
     and 
   
     Institute of Geodesy and Geoinformation of the University of Bonn (IGGB)
     Nussallee 17
     D-53115 Bonn, Germany
     
 3 - Software used:
     CALC 10.0, SOLVE release: 2008.12.05, Solve_revision: 2008.12.05
     
 4 - Data span:
     Jan 1984 - Apr 2009

 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 the 212 defining sources of ICRF-Ext1 catalogue
	 to be zero (no-net-rotation)

 6 - Terrestrial Reference Frame: vtrf2008a and associated 
                                  vtrf2008a 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 26 stations in the TRF
	 (ALGOPARK BR-VLBA  DSS45    FD-VLBA  FORTLEZA HARTRAO  HOBART26 KASHIM34
          KASHIMA  KAUAI    KOKEE    LA-VLBA  MATERA   MK-VLBA  NL-VLBA  NOTO
	  NRAO20   NRAO85_3 NYALES20 ONSALA60 RICHMOND SANTIA12 SC-VLBA  SESHAN25
          WESTFORD WETTZELL)
	 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 26 stations in the TRF
	 (ALGOPARK BR-VLBA  DSS45    FD-VLBA  FORTLEZA HARTRAO  HOBART26 KASHIM34
          KASHIMA  KAUAI    KOKEE    LA-VLBA  MATERA   MK-VLBA  NL-VLBA  NOTO
	  NRAO20   NRAO85_3 NYALES20 ONSALA60 RICHMOND SANTIA12 SC-VLBA  SESHAN25
          WESTFORD WETTZELL)
	 i.e. sum over all rotations of these stations w.r.t. TRF is zero.


     g - Reference epoch:
     
         2000.0

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

     i - Constraints for time evolution:
     
         No net velocity adjustment condition in translation 
         and rotation for 26 stations in the TRF 
	 (ALGOPARK BR-VLBA  DSS45    FD-VLBA  FORTLEZA HARTRAO  HOBART26 KASHIM34
          KASHIMA  KAUAI    KOKEE    LA-VLBA  MATERA   MK-VLBA  NL-VLBA  NOTO
	  NRAO20   NRAO85_3 NYALES20 ONSALA60 RICHMOND SANTIA12 SC-VLBA  SESHAN25
          WESTFORD WETTZELL)
         i.e. sum over all velocities adjustments in translation 
         and rotation of these stations w.r.t. TRF is zero.
         
     j - VLBI antenna axis offsets:      
     
         The values of the official list of VLBI antenna axis offsets issued by the
	 IVS Analysis Coordinator (http://vlbi.geod.uni-bonn.de/IVS-AC/Conventions/antenna-info.txt) 
         were used.


 7 - Earth orientation:

     a - A priori precession model:
     
         IERS 2003 
         
     b - A priori nutation model:
     
         IERS 2003 

     c - Short-period tidal variations in x, y, UT1:
     
         a priori short-period tidal variations in EOP were taken
         into account in accordance with IERS Conventions 2003

 8 - A priori geophysical models:
 
     a - troposphere: hydrostatic component with VMF1 mapping function
 
     b - solid Earth tide:  IERS Conventions
 
     c - ocean loading:  FES2004 model
 
     d - atmosphere loading: atmospheric pressure loading time series provided by GSFC,
                             available at http://lacerta.gsfc.nasa.gov/aplo/aplo_bds.tar.bz2 
                             (Petrov & Boy, 2004)

 9 - Estimated Parameters:

     a - Celestial Frame:
     
         right ascension and declination of all sources

     b - Terrestrial Frame:
     
         x0, y0, z0, xdot, ydot, zdot
	 and coordinates series of stations 
         AIRA, BADARY, CHICHI10, CTVASTJ, DSS13, SEST, SINTOTU3, YEBES40M            
	 estimated in respective session,
         spline coefficients for stations
         GILCREEK, HRAS_085, PIETOWN

     c - Earth Orientation:
     
         xp, xpdot, yp, ypdot, UT1-UTC, UT1dot, dX, dY of CIP, 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 generally of 50 psec/hr,
           VMF1 wet partial derivative (segmented)
         - troposphere gradients,
           offset constraint 0.5 mm, rate constraint 2.0 mm/day

10 - Technique-specific effects:

     a - Thermal expansion modelling developed by A. Nothnagel was used
         (http://vlbi.geod.uni-bonn.de/IVS-AC/Conventions/antenna-info.txt).

     b - Station eccentricities from official IVS-table were used
         (http://gemini.gsfc.nasa.gov/solve_save/ECCDAT.ecc).

References:

L. Petrov, J.-P. Boy, Study of the atmospheric pressure loading signal in VLBI observations,
Journal of Geophysical Research, 10.1029/2003JB002500, Vol. 109, No. B03405, 2004.