Hi ... and for a very low power system, there's no reason to stick with a "short" 512 bit data set, or a "fast" 1 second rep rate.
If the signal is a "only at night" sort of thing (as I'm guessing it is over that path), all you really might do is a couple of time transfers a night. A code that marked 10 minute slots would do the trick. Make it nice and long so you don't loose precision. Bob On Dec 9, 2010, at 5:55 AM, Poul-Henning Kamp wrote: > In message <[email protected]>, Hal > Murray writes: > >> Is there a similar sort of high level picture about sending timing info? >> I'm >> not even sure what the units are. > > Basically with timing you only send one bit: "now" > > The most precise way to send that bit is to use a very long PRNG > spreading code, and identify the correlator output peak using > statistical estimation on the slopes up to the peak. > > DCF77 sends a 512 bit PRNG every second and in hand-run testes I have > been able to determine the peak of the correlation with precision which > is 100-500 times better than the second to second jitter on the 1200km > propagation. > > -- > Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 > [email protected] | TCP/IP since RFC 956 > FreeBSD committer | BSD since 4.3-tahoe > Never attribute to malice what can adequately be explained by incompetence. > > _______________________________________________ > 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.
