Hardware aspects of a real-time software clock

A multi-channel digital phase recorder measures the standard frequency signals of an ensemble of atomic clocks (2 hydrogen masers + 1 caesium clock) with picosecond precision, a microcomputer compares the digital phase data, calculates in real-time an optimum synthetic time scale, and automatically tunes an VCXO to represent that scale. The software is made to generate an optimally stable time scale and continue it even in the event of a sudden non-ergodic behaviour (failure) of one of the clocks.