[time-nuts] GPS timing receivers

Poul-Henning Kamp phk at phk.freebsd.dk
Tue Oct 25 13:52:44 EDT 2005

In message <002b01c5d988$782816c0$5d30f204 at computer>, "Tom Van Baak" writes:
>> Why can't a LORAN-C Receiver recover a PPS from the LORAN-C signals?
>> Warner
>It can, and does, sort of -- but you have to first tell
>the Loran-C receiver what time it is before it knows
>which pulse is aligned to the UTC 1 PPS pulse.

The brainiacs that made the european LORAN-C chains incompatible
with practically all receivers on the market did it to make UTC
recovery possible.

Most of the chains got prime number GRIs: 7499, 7001, 9007,
with 6731 (= 53 * 127) being the exception.

Becuase they have such high least common multiple, you just have
to be able to receive three chains, and you know what time it is.

I'm probably the only person to ever having used this feature :-)

Poul-Henning Kamp       | UNIX since Zilog Zeus 3.20
phk at FreeBSD.ORG         | TCP/IP since RFC 956
FreeBSD committer       | BSD since 4.3-tahoe    
Never attribute to malice what can adequately be explained by incompetence.

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