Hi > On Sep 9, 2018, at 10:43 AM, jimlux <jimlux@earthlink.net> wrote: > > On 9/8/18 4:52 PM, paul swed wrote: >> Hello to the group I won't quote figures here but did indeed help UrsaNav >> do testing. Hey 90 days with a HP 5071 that was a sweet deal at the cost of >> some power. >> They do send corrective data in the signal from reference sites and that >> helps propagation corrections in the receive software. >> It was impressive and even in buildings no less. Its been a while so thats >> why I don't want to quote figures. >> I sort of thought all of this would have been resolved by now. But nope not >> until the S.. hits the fan and finger pointing starts. >> I do know the other satellite system lightspeed? is trying to become an >> alternate. >> Regards >> Paul >> WB8TSL > > > > But here's the problem - if "the network" is wiped out, how do you send the correction information? > > I suppose you could have a low rate network (i.e. not "the internet") and for the most part, the propagation corrections (whether using 60kHz, Loran, Omega, or GPS) can be done with "climatology" - time of day and time of year. > > BUT - if we're talking about a Carrington event or similar, a series of high altitude nuclear bursts Actually, nuclear war *is* one of the things GPS is designed to withstand …. it still is very much a military system. The same thing is true of the Russian system and one would guess, the Chinese as well. Pretty much none of the systems that use fancy timing information are designed to survive a nuclear conflict. I would suggest that’s not a really big deal. Just as with super crazy solar events, many of us will not survive it either. For those who do survive, far more basic things will be top priorities. Sure glad this is on topic for TimeNuts … Bob > - the propagation is going to be totally anomalous anyway. > > If we're talking about a evil-doer taking down GPS AND "the network" together, but not perturbing the ionosphere, there may be other things to worry about - the network carrying "time" is also carrying all those high value transactions, phone calls, etc. and that's probably a bigger business disruption than losing network sync. > > So I think GPS actually works pretty well - it will provide good sync for any non-global disaster. Likewise, a "campus" network will be able to stay synchronized, because they've got wired connections. > > In a local disaster (hurricane, earthquake) it's likely that business has been disrupted by the disaster sufficiently that time sync is less important. > > > > > > _______________________________________________ > time-nuts mailing list -- time-nuts@lists.febo.com > To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com > and follow the instructions there.

-------- In message <3d2ae1be-927a-574a-e7f0-c7d2d289dc39@earthlink.net>, jimlux writes: >On 9/8/18 4:52 PM, paul swed wrote: >I suppose you could have a low rate network (i.e. not "the internet") >and for the most part, the propagation corrections (whether using 60kHz, >Loran, Omega, or GPS) can be done with "climatology" - time of day and >time of year. Transmitting real-time corrections is not the problem, coming up with them in the first place is. One of the reasons eLoran failed to go anywhere in europe is that tests showed that modern container freighters are big enough to 'relevantly disturb Loran-C'. Nobody has a clue how you could possibly measure the necessary real-time corrections for narrow and heavily trafficked straits like as The English Channel, The Great Belt etc. For big/expensive boats, INS/IMU is the goto-solution, at around $20-50k a piece, depending on specs. In difference from anything relying on radio signals from people you can maybe trust some of the time, INS/IMU is entirely on-board, which can lower your insurance premiums if you sail certain parts of the world. -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 phk@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.

The correction stream is transmitted in the eLORAN signal and does require some form of reference site to transmitter connection. Just like GPS and lightspeed use RF to send corrections to the satellites. Loran C also did the same adjustments from a control site. But I am hearing nothing about eLORAN these days. It does not show up very often anymore in some of the navigation publications. Regards Paul WB8TSL On Sun, Sep 9, 2018 at 11:20 AM, Poul-Henning Kamp <phk@phk.freebsd.dk> wrote: > -------- > In message <3d2ae1be-927a-574a-e7f0-c7d2d289dc39@earthlink.net>, jimlux > writes: > >On 9/8/18 4:52 PM, paul swed wrote: > > >I suppose you could have a low rate network (i.e. not "the internet") > >and for the most part, the propagation corrections (whether using 60kHz, > >Loran, Omega, or GPS) can be done with "climatology" - time of day and > >time of year. > > Transmitting real-time corrections is not the problem, coming up > with them in the first place is. > > One of the reasons eLoran failed to go anywhere in europe is that > tests showed that modern container freighters are big enough to > 'relevantly disturb Loran-C'. > > Nobody has a clue how you could possibly measure the necessary > real-time corrections for narrow and heavily trafficked straits > like as The English Channel, The Great Belt etc. > > For big/expensive boats, INS/IMU is the goto-solution, at around > $20-50k a piece, depending on specs. > > In difference from anything relying on radio signals from people > you can maybe trust some of the time, INS/IMU is entirely on-board, > which can lower your insurance premiums if you sail certain parts > of the world. > > -- > Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 > phk@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. > > _______________________________________________ > time-nuts mailing list -- time-nuts@lists.febo.com > To unsubscribe, go to http://lists.febo.com/mailman/ > listinfo/time-nuts_lists.febo.com > and follow the instructions there. >

Courtesy a quick internet search: http://insidegnss.com/south-korea-developing-an-eloran-network-to-protect-ships-from-cyber-attacks/ https://rntfnd.org/wp-content/uploads/Korea-Jamming-Chart.jpg There was lots of stuff like the above. It apparently just won't stay dead. It seems one doesn't need a cataclysm - just a bad actor like North Korea. Bob Martin On 9/9/2018 9:34 AM, paul swed wrote: > The correction stream is transmitted in the eLORAN signal and does require > some form of reference site to transmitter connection. Just like GPS and > lightspeed use RF to send corrections to the satellites. > Loran C also did the same adjustments from a control site. > But I am hearing nothing about eLORAN these days. It does not show up very > often anymore in some of the navigation publications. > Regards > Paul > WB8TSL > > On Sun, Sep 9, 2018 at 11:20 AM, Poul-Henning Kamp <phk@phk.freebsd.dk> > wrote: > >> -------- >> In message <3d2ae1be-927a-574a-e7f0-c7d2d289dc39@earthlink.net>, jimlux >> writes: >>> On 9/8/18 4:52 PM, paul swed wrote: >> >>> I suppose you could have a low rate network (i.e. not "the internet") >>> and for the most part, the propagation corrections (whether using 60kHz, >>> Loran, Omega, or GPS) can be done with "climatology" - time of day and >>> time of year. >> >> Transmitting real-time corrections is not the problem, coming up >> with them in the first place is. >> >> One of the reasons eLoran failed to go anywhere in europe is that >> tests showed that modern container freighters are big enough to >> 'relevantly disturb Loran-C'. >> >> Nobody has a clue how you could possibly measure the necessary >> real-time corrections for narrow and heavily trafficked straits >> like as The English Channel, The Great Belt etc. >> >> For big/expensive boats, INS/IMU is the goto-solution, at around >> $20-50k a piece, depending on specs. >> >> In difference from anything relying on radio signals from people >> you can maybe trust some of the time, INS/IMU is entirely on-board, >> which can lower your insurance premiums if you sail certain parts >> of the world. >> >> -- >> Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 >> phk@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. >> >> _______________________________________________ >> time-nuts mailing list -- time-nuts@lists.febo.com >> To unsubscribe, go to http://lists.febo.com/mailman/ >> listinfo/time-nuts_lists.febo.com >> and follow the instructions there. >> > _______________________________________________ > time-nuts mailing list -- time-nuts@lists.febo.com > To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com > and follow the instructions there. >

Hi Back in the day, Loran was monitored and corrections were published. If you really were “time nutty” about using Loran, you got the correction tables (in the mail) and post processed them into your measurements. Bob > On Sep 9, 2018, at 11:34 AM, paul swed <paulswedb@gmail.com> wrote: > > The correction stream is transmitted in the eLORAN signal and does require > some form of reference site to transmitter connection. Just like GPS and > lightspeed use RF to send corrections to the satellites. > Loran C also did the same adjustments from a control site. > But I am hearing nothing about eLORAN these days. It does not show up very > often anymore in some of the navigation publications. > Regards > Paul > WB8TSL > > On Sun, Sep 9, 2018 at 11:20 AM, Poul-Henning Kamp <phk@phk.freebsd.dk> > wrote: > >> -------- >> In message <3d2ae1be-927a-574a-e7f0-c7d2d289dc39@earthlink.net>, jimlux >> writes: >>> On 9/8/18 4:52 PM, paul swed wrote: >> >>> I suppose you could have a low rate network (i.e. not "the internet") >>> and for the most part, the propagation corrections (whether using 60kHz, >>> Loran, Omega, or GPS) can be done with "climatology" - time of day and >>> time of year. >> >> Transmitting real-time corrections is not the problem, coming up >> with them in the first place is. >> >> One of the reasons eLoran failed to go anywhere in europe is that >> tests showed that modern container freighters are big enough to >> 'relevantly disturb Loran-C'. >> >> Nobody has a clue how you could possibly measure the necessary >> real-time corrections for narrow and heavily trafficked straits >> like as The English Channel, The Great Belt etc. >> >> For big/expensive boats, INS/IMU is the goto-solution, at around >> $20-50k a piece, depending on specs. >> >> In difference from anything relying on radio signals from people >> you can maybe trust some of the time, INS/IMU is entirely on-board, >> which can lower your insurance premiums if you sail certain parts >> of the world. >> >> -- >> Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 >> phk@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. >> >> _______________________________________________ >> time-nuts mailing list -- time-nuts@lists.febo.com >> To unsubscribe, go to http://lists.febo.com/mailman/ >> listinfo/time-nuts_lists.febo.com >> and follow the instructions there. >> > _______________________________________________ > time-nuts mailing list -- time-nuts@lists.febo.com > To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com > and follow the instructions there.