[ntp:questions] What is the "best" synchronization possible over the network?
Richard B. Gilbert
rgilbert88 at comcast.net
Wed Feb 11 04:30:33 UTC 2009
John Ioannidis wrote:
> The problem setup: two locations, both within the United States, neither
> has roof access so no GPS reception is possible. How do you synchronize
> them with better than 50-microsecond accuracy? Straight NTP over the
> Internet doesn't do the trick. They don't need to actually be
> synchronized to "real" time, they only need to be synchronized to each
> other. Assume reasonably unlimited resources (running a private fiber
> plant across the continent *is* unreasonable).
> I've looked into slaving something off a voice-carrier time base, but
> that's not accurate enough. Maybe something over raw SONET would do the
Two Atomic Clocks?? I suspect they would cost far more than you are
willing/able to spend but they would get the job done!
You could try putting a GPS antenna in a window with a southern
exposure. With the proper GPS hardware and software, once you know your
exact latitude, longitude, and elevation, you only need *one* satellite
to get the time.
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