Status report of the AIUB-METAS geodetic time transfer

The use of GPS carrier phase (CP) techniques is now widely accepted as an inexpensive and easy to use method to compare time and frequencies over long distances. A collaboration between the Astronomical Institute of the University of Bern (AIUB) and the Swiss Federal Office of Metrology and Accreditation (METAS) has produced a dedicated Geodetic Time Transfer Terminal (GeTT-Terminal) which was the subject of earlier communications. Whereas in the past these terminals have been used as mobile units and deployed at various locations, a permanent station has now been set up at METAS and shall become a site of the International GPS Service (IGS) network. In parallel AIUB, responsible for the development of the processing software and the processing of the data, has improved the time transfer tools of its Bernese GPS Software package. The focus of this paper is an efficient algorithm for the computation of a continuous time transfer series using the geodetic time transfer method. Based on the experience acquired over several years, special attention is paid to the long term stability of the analysis method.