Showing papers by "Mathias Fritsche published in 2008"

Realization of the Terrestrial Reference System by a reprocessed global GPS network

Abstract: [1] We present a GPS-only reference frame named PDR05 (Potsdam-Dresden-Reprocessing TRF 2005) based on the results of a homogeneous reprocessing of a global GPS network over the time span 1994.0–2006.0. The reference frame is realized in the center of mass (CM) system. This implies that a self-consistent model considering the reference frame and loading dynamics has been applied. The determined set of coordinates at epoch 2000.0 and their linear changes with time are evaluated in terms of self-consistency and are compared to other realizations of the Terrestrial Reference System (TRS), such as ITRF2000, ITRF2005, and the GPS-only realizations IGb00 and IGS05. We demonstrate that GPS is able to realize a TRS with the origin in the center of mass and a scale which are both on an equivalent level of self-consistency, stability, and precision as other space techniques. The results show the high potential of homogeneously reprocessed GPS networks for future International Terrestrial Reference System (ITRS) realizations and for the realization of the Global Geodetic Observing System (GGOS). Hence, PDR05 represents a stable metrological basis for global geodynamic investigations.

Observational evidence on the stability of the hydro-glaciological regime of subglacial Lake Vostok

Abstract: [1] Combined geodetic, geophysical and glaciological in situ measurements are interpreted regarding surface height changes over subglacial Lake Vostok and the local mass balance of the ice sheet at Vostok station. Repeated GPS observations spanning 5 years and long-term surface accumulation data show that the height of the lake surface has not changed over the observation period. The application of the mass conservation equation to purely observational data yields an ice mass balance for Vostok station close to equilibrium.