A Study Of The NBS Time Scale Algorithm

Since 1968 the NBS time scale algorithm has been generating a clock which is theoretically better than any of the individual clocks in its ensemble. In the last few years, thanks to the Global Positioning System, we have been able to measure the time difference between the NBS time scale algorithm and the other time standards around the world. We are able to study long term stability of the order of years, and short term stability of the order of days. We now have estimated fractional frequency stabilities for averaging times out to a year of 1*10/sup -14/. This paper studies the behavior of the algorithm from a theoretical point of view, characterizing its performance.