TRG vs GPS Statistics of 990423

Plots of 24 hours

from 04-23-1999 00:00:02 to 04-23-1999 23:59:57


Relative time between spills (via TRG 48-bit clock)



same as above, but zoomed in [2.17 ... 2.21] and with histogram



TRG oscillator drift from 50 MHz (*1)


Absolute spill time difference between GPS1 and GPS2


Absolute spill time difference between GPS1 and GPS2, zoomed


Relative spill time difference between GPS1 and TRG (*2)


Relative spill time difference between GPS1 and TRG, zoomed (*2)


Relative spill time difference between GPS2 and TRG (*2)

Plots of 7 days

from 04-17-1999 00:44:59 to 04-23-1999 23:58:58


Relative time between spills (via TRG 48-bit clock)



same as above, but zoomed in [2.17 ... 2.21] and with histogram


TRG oscillator drift from 50 MHz (*1)


Absolute spill time difference between GPS1 and GPS2


Relative spill time difference between GPS1 and TRG (*2)


Relative spill time difference between GPS2 and TRG (*2)

Histograms

Note: y axis is log scale, i.e. 0 => 1 spill, 1 => 10 spills, 2 => 100 spills, etc.




Notes

(*1)   Both, the TRG module and LTC module each use an internal, free-running 50 MHz crystal oscillator (independent) for their clock counters. The two oscillators are not temperature compensated! Therefore, any change of the room temperature in the North Hall control room causes them to drift. Cooler temperatures usually result in higher frquencies than at warmer temperatures.
(*2)   Absolute TRG clock vs. GPS time measurements cannot be made due to the mentioned temperature-dependent TRG oscillator drifts, as shown in the wave forms of the plots above. The waves are inverse proportional to temperature changes in the North Hall.