Hi A traveling clock process is still the only way to fully validate a local time setup. The NIST modems can get close, but a clock (second opinion) is the only way to be sure.
Bob On Mar 3, 2014, at 9:09 PM, Tom Van Baak <[email protected]> wrote: > Hi Jim, > > Nice video. I had not see that old one before. Someone at NPL must be going > through archives. That's very nice of them to post it. Did anyone spot the > date of the filming? > > My understanding is that the era of traveling clocks gradually ended as > various methods of satellite time transfer began. However people still use > "traveling clocks" today as a backup for GPS, or to double check GPS, or in > places where GPS cannot be received, or when one needs accurate results > quickly without waiting for GPS averaging or post-processing. So the practice > is not dead. Most recently we all saw it used to validate the neutrino timing > experiments. > > Traveling clocks can also be used to demonstrate time dilation: > http://leapsecond.com/great2005/ > > For more info on the traveling clock era make sure to read these four HPJ > articles: > > World-Wide Time Synchronization, 1966 > http://www.hpl.hp.com/hpjournal/pdfs/IssuePDFs/1966-08.pdf, page 13 > > A New Performance of the "Flying Clock" Experiment > http://www.hpl.hp.com/hpjournal/pdfs/IssuePDFs/1964-07.pdf, page 1 > > Correlating Time from Europe to Asia with Flying Clocks > http://www.hpl.hp.com/hpjournal/pdfs/IssuePDFs/1965-04.pdf, page 1 > > 'Flying Clock' Comparisons Extended to East Europe, Africa and Australia > http://www.hpl.hp.com/hpjournal/pdfs/IssuePDFs/1967-12.pdf > > /tvb > > ----- Original Message ----- > From: "Jimmy Burrell" <[email protected]> > To: "Discussion of precise time and frequency measurement" > <[email protected]> > Sent: Monday, March 03, 2014 5:17 PM > Subject: [time-nuts] Time transfer, internationally before GPS > > >> My apologies to the list if this has been posted before but I found it >> fascinating. I'm guessing this was early 60's. >> >> I wonder if this practice continued until the advent of GPS? I be interested >> to know if there was an interim technology and what it was. >> >> http://youtu.be/SXV4c5eVkE4 >> >> >> Jim... >> N5SPE >> _______________________________________________ >> time-nuts mailing list -- [email protected] >> To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts >> and follow the instructions there. >> > > _______________________________________________ > time-nuts mailing list -- [email protected] > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
