State-of-the-art time link calibration with a mobile TWSTFT station

Two-Way Satellite Time and Frequency Transfer (TWSTFT) using geostationary telecommunication satellites has become an important technique for comparing remote timescales. There is a need for periodic calibration of the signal delays along the links which are part of the network for the realization of the International Atomic Time (TAI). In order to minimize the efforts of such TWSTFT calibration campaigns, TimeTech GmbH has assembled a mobile station on a trailer. The trailer contains the usual TWSTFT equipment, including the two-way modem, the up/down converters, filters, and amplifiers, as well as monitoring systems, air conditioner, and weather sensors. The steerable antenna is mounted on top of the trailer. The 1 PPS and 10 MHz signals required as input to the TWSTFT equipment are transferred from inside the timing laboratory by an optical link and two reference generators in a master-slave configuration.