First Results of GPS Time Transfer to Australia

A global positioning system (GPS) time transfer unit was installed at Tidbinbilla Deep Space Communications Complex of the DSN in June 1983. It was used to estimate the relationship to UTC(USNO MC) of the Tidbinbilla frequency and time system TID(FTS) based on a hydrogen maser, and to estimate the performance of the Australian free-running time scale UTC(AUS). Data from the first 3 months were analyzed three ways: by two-hop common view using JPL as intermediary; by long-arc interpolation of measurements against space vehicle clocks; and by long arc interpolation of GPS-Time results. Residuals from a single quadratic fit through 3 months of UTC(USNO MC) -TID(FTS) results were white noise with standard error 15 ns, and a flying clock measurement gave 70 ns agreement. A straight line fit through results UTC(USNO MC) - UTC(AUS) gave 90 ns standard error and 120 ns agreement. It is proposed to use the GPS measurements to steer UTC(AUS) to UTC(BIH), and to rename the existing time scale TA(AUS).