HR: 17:45h
AN: G34A-08    [Abstracts]
TI: Celestial Motion of Earth's Spin Axis Derived From the Combination of VLBI and GPS Observations
AU: * Vondrak, J
EM: vondrak@ig.cas.cz
AF: Astronomical Institute, Bocni II, Prague, 141 31 Czech Republic
AU: Ron, C
EM: ron@ig.cas.cz
AF: Astronomical Institute, Bocni II, Prague, 141 31 Czech Republic
AU: Weber, R
EM: rweber@luna.tuwien.ac.at
AF: University of Technology, Gusshausstr. 27, Vienna, 1040 Austria
AB: The motion of Earth's spin axis in space is monitored by VLBI, and since 1994 also its rate is measured by GPS. The method of "combined smoothing", developed recently at the Astronomical Institute in Prague, enables to combine both series. The solution, based on observations in 1979.6-2004.5, is compared with the recently adopted IAU2000 model of precession-nutation. The analysis reveals statistically significant deviations from the model. These differences can be identified with free core nutation (FCN) and several forced nutation terms.
DE: 1229 Reference systems
DE: 1239 Rotational variations
DE: 1294 Instruments and techniques
SC: Geodesy [G]
MN: 2004 AGU Fall Meeting