>From my Austron days (and I'm sure technology may have moved a bit since then), we always reckoned on about 1 microsecond as a fairly good accuracy for a standalone LORAN-C timing receiver.
Rob Kimberley -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of John Ackermann N8UR Sent: 20 January 2007 12:57 To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] US considers shutting down Loran Hal Murray said the following on 01/19/2007 11:12 PM: > From http://www.fcw.com/article97298-01-08-07-Web > >> Norman said the Alliance for Telecommunications Industry Solutions >> (ATIS), whose membership includes all the telecom carriers in the >> country and equipment vendors, views eLoran as the "only viable >> alternative to GPS for providing [Coordinated Universal Time] of day >> and frequency accuracy that is suitable for a telecom primary >> reference source." > > How good is Loran for timing? What's the right parameter for "good"? When used for frequency measurement, Loran is good to parts in 10e-13/day -- ie, not much worse than GPS. Of course, that's referenced to the Cesium clock at the Loran station, so you need to do a little juggling to trace back to NIST. I believe that as they enhance the stations to the new hardware, the discrepancy from NIST will be much less. I recently got one of the (relatively rare) Austron 2100-T Loran receivers that do timing; you basically lock the receiver to one of the periodic Loran pulses that coincides with a UTC second marker and it generates a PPS signal tracking that. I haven't had a chance yet to run any long-term experiments to measure its stability, but that's on my list of things to do. (I also plan to hook it up as a refclock for an NTP server; I'm not sure if there's another Loran-based stratum 1 server out there today.) John John _______________________________________________ time-nuts mailing list [email protected] https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts _______________________________________________ time-nuts mailing list [email protected] https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
