Description of the TWSTFT Station at METAS and Presentation of the Calibration Campaign 2006

A fully automated two-way satellite time and frequency transfer (TWSTFT) station has" been built at METAS. This station has participated in the TWSTFT schedule on a regular basis since January 2005. In the Summer of 2006, the TWSTFT links between METAS, PTB and TUG were calibrated in a specific campaign using the mobile earth station of TUG. In the first part of this communication, technical details on the TWSTFT station at METAS and the data handling are presented. During the setting up of the earth station at METAS, special care was taken to ensure stable environmental conditions for the hardware. Emphasis was also placed on communication interfaces, made independent from the METAS LAN to avoid disruption of the automated TWSTFT station in the event of IT network failures. In the second part of the article, the calibration campaign and its outcome are described. The main result was the determination of the calibration constants of the links involved with combined uncertainties of 0.8 ns (1sigma). The calibration data have been reported in the result files since December 2006. With a fully automated and calibrated TWSTFT station at METAS, UTC(CH) can now be tied to UTC via TWSTFT measurements.