A SYSTEMS-LEVEL ANALYSIS OF THE JHU/APL TIME AND FREQUENCY LABORATORY

摘要

In past years, we have reported on continuous improvement in the operation of the master clock of our Time and Frequency Laboratory at the Johns Hopkins University Applied Physics Laboratory. We have discussed our ensemble of hydrogen maser and cesium beam atomic frequency standards into an autonomous timescale that maintains UTC (JHU/APL) within ± 20 ns per month of UTC. This year, since completing the major aspects of our laboratory refurbishment, we have undertaken systems analysis toward optimization and improved timekeeping. In our paper, we will describe the system of clocks, control mechanisms, and their relationship that maintain our laboratory's accuracy. One outcome will describe the determination of our worst performing clock through frequency characterization and the performance improvement in the UTC (JHU/APL) timescale through selectively weighting its contribution.