The influence of antenna direction on TWSTFT

The two-way satellite time and frequency transfer (TWSTFT) is the most accurate time synchronization method currently. Antenna is an indispensable element and plays an important role in the earth station of TWSTFT, its direction has a definite effect on the signal quality and performance in TWSTFT. In this paper, some preliminary test results are introduced by using the new TWSTFT system of Ku band with a 2.4 meters tracking antenna in National Time Service Center (NTSC). Through the experiment, we have obtained some data according to different antenna direction, by the analysis we can know: the change of azimuth angle is more sensitive than elevation angle during receiving the signal; in theory, the biggest deviation of azimuth angle should be symmetrical in both sides and asymmetric actually, the deviation of elevation angle is also. The deviation is the angle apart from the pointing of antenna at which receiving signal is the best. It can offer a powerful reference for antenna pointing deviation in earth station of TWSTFT and provide theoretical foundation for the antenna direction and high precision time transfer and synchronization.