THE LONG-TERM STABILITY OF THE U.S. NAVAL OBSERVATORY'S MASERS

摘要

The U. S. Naval Observatory (USNO) currently maintains 20 cavity-tuned hydrogen maser frequency standards at its Washington, DC (USNO-DC) and Alternate Master Clock (USNO-AMC) facilities, of which 13 have been in use for at least 7 years. This paper analyzes and characterizes the long-term frequency behavior of these masers, as observed.