A reference value of time and time interval. Standards of time and frequency are determined by astronomical observations and by the operation of atomic clocks and other advanced timekeeping instruments. They are disseminated by transport of clocks, radio transmissions, satellite relay, and other means.
TIME AND FREQUENCY STANDARD
Meaning of TIME AND FREQUENCY STANDARD in English
DOD English dictionary of military terms. Английский словарь военных терминов DOD. 2012