[time-nuts] Position accuracy and Thunderbolt performance

[Mark Sims]

I did a rather interesting test on the effects of the survey position accuracy on the Thunderbolt.  Attached are two plots.  The first one is with the Tbolt position within three feet of the actual location.  The second show the results when the Tbolt is told it is 200 feet from where it actually is.  

The graphs are scaled to the same scale factors.  The jumps in the 200 foot graph are NOT correlated to satellite constellation changes, etc.  The self-reported performance is degraded by a factor of around 10.  

The quantization and structure of the 200 foot graph is totally unexpected.  It may help explain things like the DAC spikes in divisions 5 and 7 of the 3foot.gif graph.
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