High-accuracy global time and frequency transfer with a space-borne hydrogen maser clock

This paper describes a proposed system for high-accuracy global time and frequency transfer using a hydrogen maser clock in a space vehicle. Direct frequency transfer with an accuracy of 10(-14) and time transfer with an estimated accuracy of 1 nsec are provided by a 3-link microwave system. A short pulse laser system is included for subnanosecond time transfer and system calibration. The basic concept of such a system was discussed at the 1980 PTTI Meeting. This paper presents the results of further studies including operational aspects, error sources, data flow, system configuration, and implementation requirements for an initial demonstration experiment using the Space Shuttle.