Fig. 3: Clock output frequency timeseries.
From: Demonstration of a mobile optical clock ensemble at sea
Frequency vs time measurement of the 100 MHz RF outputs of the three clocks directly measured by the frequency counter during different stages of the trial. The three systems have been offset by 200 × 10−12 for clarity. The ORAFS data has been processed to remove shifts between data segment due to changes in the comb mode index used for optical to RF down-conversion. An additional offset of 2 × 10−9 has been removed from three segments of ORAFS data in which the clock was operated in a different locking scheme — denoted by a box with star (*).
