Study On The Stability Of Two Way Satellite Time And Frequency Transfer

With the development of science and technology, time and frequency isplaying an important role in many fields. Two way satellite time andfrequency transfer (TWSTFT) is one of the most accurate and precise methodsfor comparing of time remote clocks. In this paper we analyze the instabilityon TWSTFT.The main contributions are as follows:1. Temperature effect on TWSTFTSome of TWSTFT equipments are placed at outside door, so the varies ofdelay for instrument with temperature are not ignored. In this paper wediscussed its influence on TWSTFT with temperature.2. Effect of satellite motion on TWSTFTSince the motion of geostationary satellite the paths for up link anddown link are different. Others effect include: Earth rotation ,ionosphere,troposphere,rain attenuation, etc.3. The algorithm for multi-station is better than an algorithm withsingle-channel for multi-station on TWSTFT. The algorithm formulti-station is used on the Asia-Pacific links, we get the benefit fromthis algorithm. We analyze the diurnal variations in TWSTFT.4. Multi-channel Modem is used on TWSTFT. The performance of single-channelModem and multi-channel is evaluated.5. A new method which is suited for TWSTFT data is presented. The new methodhas designed for uneven spaced data, but Allan variance has only designedfor regular spaced data.