New steering strategies for the usno master clocks

摘要

All U.S. Naval Observatory (USNO) steering situations involve ompromises to minimize the degradation of short-term stability of a steered clock while gaining maximal benefits from the long-term stability of the reference. In the case of steering UTC*USNO) to UTC, extra complications arise due to the 30-day data interval and the 15-day delay associated with the transfer of new information. A technique that minimizes the amount of control required to steer the USNO mean to UTC will be presented. Different strategies designed for optimal steering of UTC(USNO) and a backup master clock system located at the USNO will be described. Some of these strategies involve steering a maser to an intermediate mean that is steered to an extrapolation of UTC. Examples of optimal steering on real data will be reported.