Abstract

In NASA’s Deep Space Network (DSN), the phase stability of the clock synchronization link connecting various antenna sites ultimately determines the accuracy of the system’s tracking and very long base line interferometry (VLBI) measurements. Use of a multimode optical fiber to improve the stability of this loop was shown previously to be comparable with the best coaxial cables.¹ A Single-mode fiber should improve the bandwidth-distance product considerably, thereby permitting either greater station separations or a higher frequency synchronization signal.

© 1981 Optical Society of America