The comparison between TWSTFT and GPS time transfers on inter-continental baseline links

This study compares the results of different kinds of the precise time transfer techniques and estimates their qualities. Four laboratories equipped with the two-way satellite time and frequency transfer (TWSTFT) stations and dual frequency GPS multi-channel receivers are chosen for the representative sites of Europe, North-American and Asia. We investigate the difference between TWSTFT and different kinds of GPS data, including the continuous GPS code combined with Carrier-Phase solutions, GPS Multi-Channel C/A code, GPS P3 code Common-View and All-in-View. This study shows that TWSTFT and GPS data are in good agreement. The standard deviations of their double difference could be in the order of sub-nanosecond.