Precise time transfer activities in singapore

Precise time transfer is one of the essential works for time-keeping laboratories in maintaining the standards of time and frequency. At the National Metrology Centre (NMC) in Singapore, we have been seeking to improve the time scale performance and time transfer capability by employing different time transfer techniques. Currently, three different time transfer systems are used in the laboratory, namely, GPS code observation by a single frequency multi channel receiver and a dual frequency multi channel receiver; GPS carrier phase observation by geodetic receiver; two way satellite time and frequency transfer (TWSTFT). In this paper, the results of time links between NMC and other Asian and European laboratories are presented, using GPS C/A and TWSTFT techniques.