Report on the master clock upgrade program at USNO

Abstract

A history is given of the Master Clock Upgrade Program at USNO and the current status of the program is described. Performance data on the hydrogen masers and stored ion devices are presented. Current projects are described including a time difference measurement system, time scale algorithm test bed, and the novel masers to be added over the next 18 months. A prediction of the status and performance of the program in two years is made.<>