HR: 09:40h
AN: G21B-07    [Abstracts]
TI: Towards a Refined Realisation of the Terrestrial Reference System
AU: * Angermann, D
EM: angermann@dgfi.badw.de
AF: Deutsches Geodaetisches Forschungsinstitut, Marstallplatz 8, Muenchen, 80539 Germany
AU: Drewes, H
EM: drewes@dgfi.badw.de
AF: Deutsches Geodaetisches Forschungsinstitut, Marstallplatz 8, Muenchen, 80539 Germany
AU: Meisel, B
EM: meisel@dgfi.badw.de
AF: Deutsches Geodaetisches Forschungsinstitut, Marstallplatz 8, Muenchen, 80539 Germany
AU: Kruegel, M
EM: kruegel@dgfi.badw.de
AF: Deutsches Geodaetisches Forschungsinstitut, Marstallplatz 8, Muenchen, 80539 Germany
AU: Tesmer, V
EM: tesmer@dgfi.badw.de
AF: Deutsches Geodaetisches Forschungsinstitut, Marstallplatz 8, Muenchen, 80539 Germany
AB: Global reference frames provide the framework for scientific investigations of the Earth's system (e.g. plate tectonics, sea level change, seasonal and secular loading signals, atmosphere dynamics, Earth orientation excitation), as well as for many practical applications (e.g. surveying and navigation). Today, space geodetic techniques allow to determine geodetic parameters (e.g. station positions, Earth rotation) with a precision of a few millimeters (or even better). However, this high accuracy is not reflected by current realisations of the terrestrial reference system. To fully exploit the potential of the space geodetic observations for investigations of various global and regional, short-term, seasonal and secular phenomena of the Earth's system, the reference frame must be realised with the highest accuracy, spatial and temporal consistency and stability over decades. Furthermore, future progress in Earth sciences will fundamentally depend on understanding the Earth as a system, into which the three areas of geodetic research (geometry/deformation, Earth rotation, gravity) are to be integrated. The presentation focusses on various aspects that must be considered for a refined realisation of the terrestrial reference system, such as the development of suitable methods for the combination of the contributing space geodetic observations, the realisation of the TRF datum and the parameterisation of site motions. For this purpose we investigated time series of station positions and datum parameters obtained from VLBI, SLR, GPS and DORIS solutions, and compared the results at co-location sites and with other studies. Furthermore, we present results obtained from a TRS realisation based on epoch (weekly/daily) normal equations with station positions and daily Earth Orientation Parameters (EOP) using five years (1999-2004) of VLBI, SLR, GPS and DORIS data. This refined approach has major advantages compared to past TRF realisations based on multi-year solutions with station positions at a given epoch and constant velocities, as for instance non-linear effects of site positions and datum parameters can be considered, and consistency between TRF and EOPs can be achieved. First results of this new approach are promising.
DE: 1229 Reference systems
DE: 1247 Terrestrial reference systems
SC: Geodesy [G]
MN: 2004 AGU Fall Meeting