On Sep 9, 2010, at 12:03 PM, Ralph Smith wrote: > 1e-11 only buys you 3000 seconds of drift before blowing the 30 ns budget. > Without going to cesium we will most likely need some form of mutually > visible synchronization.
How about a rubidium or cesium standard at each site for holdover, with an extra cesium standard that is physically carried from site to site (say, by helicopter) during an extended holdover period to distribute a common time reference around? Or, a specially-equipped aircraft which is periodically flown along paths visible to multiple antenna sites during an extended holdover in order to adjust out drift based on measured round-trip times between the sites and aircraft? In effect, flying your own low-altitude satellite over the sites when the GPS system is down. These may be silly ideas, but brainstorming is fun. -- Mark J. Blair, NF6X <n...@nf6x.net> Web page: http://www.nf6x.net/ GnuPG public key available from my web page. _______________________________________________ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
