[time-nuts] Time in a cave

[Lamar Owen]

On 05/12/2015 07:00 PM, Tucek, Joseph wrote:
> I'm looking for information on non-GPS time sources.
>
> ...
> My endgame worst case is to just do PPS from a stratum 2 NTP (or even a freerunning oscillator) and lie to my PTP server; hard sync to UTC is a secondary concern so long as the cluster agrees with itself.  Endrun is looking pretty good, but I'd really like to have a second option to compare against.
>
Would WWVB meet your requirements for periodic comparisons, or is this 
place too noisy for that? When you say 'cave' how deep are you talking?