Local Clocks quality Evaluation Subsystem

This paper presents the design, operation and test results of a Clocks Evaluation Subsystem (CES) developed for the EUREKA's research project called Legal Time Distribution System (LTDS). The main aim of the CES is to gather information about time drift of the tracked clocks, then to evaluate their stability, and finally to select the most stable one as a local reference clock. The CES contains three main functional blocks: 3-channel time interval counter [1], distribution amplifier and set of three local clock sources, i.e. low noise chip scale atomic clocks (LN CSAC, Microsemi).