Thursday 25 August 2005

G1
1530-1700 hours

425
Frontiers in the combination of space geodetic techniques
Kruegel, Manuela¹, Angermann, Detlef¹
1 Deutsches Geodaetisches Forschungsinstitut, Munich, Germany
Author email: kruegel@dgfi.badw.de
This contribution deals with new strategies for the selection and implementation of local ties based on time series of space geodetic solutions containing station positions and Earth Rotation Parameters (ERP). Co-location sites are key elements in the combination of the reference frames of different space geodetic techniques. They are fundamental for a consistent datum realisation of the combined networks, which was performed in recent TRF solutions by introducing local ties and by combining station velocities of co-located instruments. As it was shown in Angermann et al. 2004 and Kruegel et al. 2005 the selection of local ties is difficult because the spatial distribution of 'high-quality' co-location sites is not optimal. This paper focusses on strategies for the selection and implementation of local tie information using the ITRF2004 submissions as input data. Compared to past TRF computations based on multi-year solutions with station positions and constant velocities, time series of stations positions and ERP were provided for ITRF2004 computation. As common parameters of the different geodetic space techniques, the ERP represent an additional global tie and stabilize the consistency of the rotation datum. Furthermore the ERP values provide additional possibilities for local tie validation. Main criteria for the selection of co-location sites are a high consistency in the datum realisation of the combined networks and a minimal deformation of the networks due to the combination. Furthermore the potential of a combination was investigated using only the distances between the reference points of different instruments. The new strategies for local tie implementation and inter-technique combination are an important contribution for ITRF2004 computation. References: Angermann et al.,2004, DGK, Reihe B, Heft Nr. 313 Kruegel et al.,2005, Proc. of the IERS Workshop on Site Co-location, Matera, 2003 (in press).

Return to Oral Presentations