> Loran can do great frequency measurement -- almost as good as GPS. But > for timing, it's not so hot. The problem with current Loran is that it > doesn't carry a timecode, or mark the second epoch. It's possible to > recover 1pps from Loran with a bit of work (the Austron 2100T receiver > can do this) but it's not a trivial task, and in any event you need > something else to disambiguate the seconds. > > John
I agree with you that Loran-C makes a very good frequency reference. I also suspect there are applications where Loran-C is superior to GPS (antenna placement, reliability, noise immunity, etc.), or can at least augment GPS or local cesium clocks for increased timing redundancy. I've had various flavors of Austron and Stanford Research FS700 Loran-C receiver running for years here and now regret not logging them continuously so I could give you all a nice Loran-C ADEV plot out to a year... But for those of you interested, here is a quick graph showing the output of a FS700 for shorter tau. http://www.leapsecond.com/museum/fs700/ The peak near 2000 seconds is just like what you see with a GPSDO (and for the same reason). Compare the plot above to this typical GPSDO: http://www.leapsecond.com/museum/58503b/log2774v.gif It will be interesting to see what happens at longer tau but so far it looks like this Loran-C receiver is within one decade of the 50503B. /tvb _______________________________________________ time-nuts mailing list [email protected] https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
