Preliminary Analysis of a Proposed High-Stability Frequency Standard Distribution System

Abstract

This paper presents the results of a preliminary analysis of a satellite-borne system for distributing a reference frequency over global distances with an accuracy and stability apparently at least as good as those of independent atomic standards. This system is designed to distribute an accurate time scale [1], which could be used for time keeping, but not for transmitting epoch information. Epoch synchronization via synchronous satellite has been accom-The most stable standards are the primary atomic frequency standards [31, [41, and these form the basis for some of the time scales in use [11, [51 . A stability of 1 part in 1014 for 30 minutes averaging time for a hydrogen maser has been reported [3]. To be worthwhile, any complex distribution system should be able to equal-if not surpassthis stability. AbstractA system for distributing a frequency reference, which involves the use of geostationary satellites and two-way microwave transmissions, seems capable of stabilities exceeding those of primary atomic standards. The principal sources of error are instabilities in oscillators in the system, imperfect geostationary orbits, additive noise, and radio propagation effects. Even extreme assumptions of propagation phase instability lead to very small errors. Thus the limitations on stability seem to be imposed by the hardware.