NIST has published a comprehensive guide covering various aspects of timekeeping and frequency measurement standards. The document defines key terms and technologies, including:
Clocks: Devices that generate precise, regular signals for timekeeping, consisting of an oscillator, counter, and display/recording system.
Characterization: An in-depth testing process to evaluate a clock’s performance characteristics over time under different conditions.
Chip Scale Atomic Clocks (CSACs): Miniature atomic clocks developed by NIST in 2001, now commercially available, offering parts-per-trillion stability based on cesium or rubidium resonance.
Common-View: A method to compare remote clocks by sharing a common reference signal, reducing uncertainty by canceling common path delays.
Coordinated Universal Time (UTC): The international atomic time scale used for global timekeeping, differing from International Atomic Time (TAI) by whole seconds and incorporating leap seconds to align with Earth’s rotational time.
Cycle Slip: A tracking error in carrier frequency measurements, causing phase shifts due to signal noise or loss of lock.
The guide aims to provide a comprehensive reference for understanding and implementing timekeeping and frequency measurement standards.
Keywords: Clock, Characterization, Chip Scale Atomic Clock (CSAC)
