The U. S. Naval Observatory Clock Time Scales

Several changes have recently been made to improve the real time physical approximation of UTC(USNO), the coordinated time scale generated by the U. S. Naval Observatory. A provisional UTC(USNO) is generated in real time, and a physical clock is steered to this time scale by a phase microstepper. When final values for UTC(USNO) are available, a method has been devised to steer the real time UTC(USNO) to match the final UTC(USNO). Further improvement will involve the adoption of an algorithm to generate UTC(USNO) on a real-time basis. Details of this new algorithm are presented.