Automated Timekeeping

An automated data collection and processing system designed to maintain and control the U. S. Naval Observatory (USNO) master clock system is described. Phase difference and time interval measurements (better than 0.1-ns resolution and 1.0-ns precision) from an ensemble of atomic clocks are used to construct a master clock time scale with a stability of parts in 10-14 on a near real time basis. Physical realization and dissemination of the time scale is achieved through program-controlied subsystems. The control and automatic data processing (ADP) systems are discussed and an analysis of system performance is made.