Slave clocks

In telecommunication and horology, a slave clock is a clock that depends on another clock, the master clock. Modern clocks are synchronized through the Internet or by radio time signals, to Coordinated Universal Time. UTC is based on a network of atomic clocks in many countries. For scientific purposes, precision clocks can be synchronized to within nanoseconds by dedicated satellite channels. Slave clock synchronization is usually achieved by phase-locking the slave clock signal to a signal received from the master clock. To adjust for the transit time of the signal from the master clock to the slave clock, the phase of the slave clocks are adjusted so that both clocks are in phase. Thus, the time markers of both clocks, at the output of the clocks, occur simultaneously.