Time Transfer Methodologies for International Atomic Time (TAI)

摘要

While there are many forms of time-transfer, the most precise long- distance forms currently used for the generation of International Atomic Time (TAI) and Coordinated Universal Time (UTC) involve either GPS or Two Way Satellite Time and Frequency Transfer (TWSTFT). This paper gives a brief description of their current and future capabilities, with emphasis on how their uncertainties affect UTC. Some of these uncertainties are due to inherent modeling or receiver instabilities, while others can be reduced through temperature and humidity stabilization, electronic impedance matching, and multipath minimization. The residual time-transfer uncertainties directly affect the uncertainties in each individual laboratory's realization of UTC.