[time-nuts] 1 pps Accuracy in two locations

[Skip Withrow]

Hello Martyn,
This is exactly the problem that all the national time services have
trying to formulate UTC (USNO, NIST, GPS, BIPM, and all the other
contributors).  There are a number of techniques in place - traveling
clocks, common view, two-way satellite time transfer, post processing.
Nanoseconds are easy, hundreds of picoseconds can be done, but
picoseconds - not so much.

Obviously, time transfer between optical clocks has been done down in
the 10E-18 range which gets you there.  But you're talking large
budgets.  At 1ns per foot even the position of your antenna (if using
GPS) matters by less than a millimeter.

If it was easy - every time-nut would be doing it!

Do let me know if you come up with a solution.
Skip Withrow