0 - Technical description of solution bkg2009a.crf
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.