HR: 0800h
AN: G41B-0353    [Abstracts]
TI: Challenges Towards a Uniform Terrestrial Reference Frame
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: Kruegel, M
EM: kruegel@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
AB: Nowadays space geodetic observation techniques play a prominent role in detecting, quantifying and monitoring of spatial and temporal changes of the Earth's shape (e.g., land surfaces, sea surfaces, ice covers) and the gravity field. The phenomena to be detected are generally very small (e.g., at the millimeter level) and thus difficult to be observed reliably without systematic distortions of the results. To fully exploit the potential of the space geodetic observations it is important to take advantage of the specific strengths and to avoid the weaknesses of the individual techniques. To reliably estimate the geodetic-geophysical parameters a uniform terrestrial reference frame must be realized for geometry and global gravity field models with the highest accuracy, spatial and temporal consistency and stability over decades. At DGFI, an ITRS Combination Center has been establisbed and methods for an improved realization of the terrestrial reference frame (TRF) have been developed. The refined approach is based on the combination of epoch normal equations (weekly/daily data sets) containing station positions and Earth orientation parameters (EOP) which allows to account for all nonlinear effects (e.g., periodic signals, discontinuities) in station positions and to ensure consistency between the TRF, EOP and GGM datum (one and two degree spherical harmonics). In this presentation we address various relevant issues, such as the effect of non-uniform spatial and temporal distribution of the geodetic networks and the key role of co-location sites for integrating different space techniques, identifying common signals in the parameter time series and detecting remaining technique-specific problems. Other issues that are addressed include the weighting of different techniques and the realization of the geodetic datum for the TRF computation.
DE: 1229 Reference systems
DE: 1295 Integrations of techniques
SC: Geodesy [G]
MN: Fall Meeting 2005