Re: [time-nuts] Loran in the US
Hi A lot depends on weather it's 50 ns right out of the spout (1 second samples or what ever) or if it's a couple day average. There are a number of odd things that happen with the sunrise and sunset. Bob -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Poul-Henning Kamp Sent: Friday, March 09, 2012 3:16 AM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] Loran in the US In message <9d1dabc0-ae63-4fb5-ad7d-d8c42f9fd...@gmail.com>, Dennis Ferguson wr ites: >> If so, frequency stability is priority number one and time is >> probably just "better than 100msec" or so > >I could swear I saw something that said "50 ns", though I can You can _almost_ do that with loran, if you know your l/l coords. >indicates they aren't just looking at Loran by itself. The >MF dGPS bands and 500 kHz are also included in whatever they >are doing. Which indicates to me that they are pretty damn serious, and not just catering to some recently discovered VIP Loran-C users. I'd be very surprised if LightSquared nuking GPS reliability doesn't have something to do with this. -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 p...@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@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Loran in the US
In message <9d1dabc0-ae63-4fb5-ad7d-d8c42f9fd...@gmail.com>, Dennis Ferguson wr ites: >> If so, frequency stability is priority number one and time is >> probably just "better than 100msec" or so > >I could swear I saw something that said "50 ns", though I can You can _almost_ do that with loran, if you know your l/l coords. >indicates they aren't just looking at Loran by itself. The >MF dGPS bands and 500 kHz are also included in whatever they >are doing. Which indicates to me that they are pretty damn serious, and not just catering to some recently discovered VIP Loran-C users. I'd be very surprised if LightSquared nuking GPS reliability doesn't have something to do with this. -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 p...@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@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Loran in the US
On 8 Mar, 2012, at 02:58 , Poul-Henning Kamp wrote: > Has anybody asked them how good time&freq they're trying to deliver ? > > I would assume that they are aiming for a backup for GPS in > telecom-GPSDO context. > > If so, frequency stability is priority number one and time is > probably just "better than 100msec" or so I could swear I saw something that said "50 ns", though I can no longer find it and that sounds like science fiction. I note, though, that the Federal Register publication for the project, here: http://www.gpo.gov/fdsys/pkg/FR-2012-01-11/html/2012-307.htm indicates they aren't just looking at Loran by itself. The MF dGPS bands and 500 kHz are also included in whatever they are doing. Dennis Ferguson ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Loran in the US
Hi Indeed, you *can* use GPS for a lot of things. You pretty much *must* use it for CDMA. Bob On Mar 8, 2012, at 6:36 PM, Magnus Danielson wrote: > On 03/09/2012 12:16 AM, Bob Camp wrote: >> Hi >> >> SDH/SONET generally is line timed rather than GPS locked. It's ultimate >> authority is the Stratum 1 above it... > > Yes, but GPS/LORAN can be used to build holdover synchronisation, and verify > the local cesiums. > > Stratum 1 is the ANSI T1.101 name, also known as PRC in SDH, which is ITU-T > G.811. > > Cheers, > Magnus > > ___ > time-nuts mailing list -- time-nuts@febo.com > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Loran in the US
On 03/09/2012 12:16 AM, Bob Camp wrote: Hi SDH/SONET generally is line timed rather than GPS locked. It's ultimate authority is the Stratum 1 above it... Yes, but GPS/LORAN can be used to build holdover synchronisation, and verify the local cesiums. Stratum 1 is the ANSI T1.101 name, also known as PRC in SDH, which is ITU-T G.811. Cheers, Magnus ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Loran in the US
Hi SDH/SONET generally is line timed rather than GPS locked. It's ultimate authority is the Stratum 1 above it... With CDMA framing, GPS time is actually the ultimate authority. With GSM (as with the CDMA carrier frequency) a free running oscillator is generally "good enough". Bob On Mar 8, 2012, at 5:27 PM, Magnus Danielson wrote: > On 03/08/2012 11:21 PM, Bob Camp wrote: >> Hi >> >> Should be *very* interesting to watch if they try to legislate something >> like that... > > Indeed. > > There are different telecom needs. CDMA isn't everything. > > SDH/SONET goes under G.811, meaning within 1E-11 in frequency. > GSM should be within +/- 50 ppb, but long-term should be like SDH/SONET. > etc. etc. > > Cheers, > Magnus > >> Bob >> >> -Original Message- >> From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On >> Behalf Of Poul-Henning Kamp >> Sent: Thursday, March 08, 2012 5:10 PM >> To: Discussion of precise time and frequency measurement >> Subject: Re: [time-nuts] Loran in the US >> >> In message, "Bob Camp" >> writes: >> >>> If they are backing up GPS for telcom, then CDMA timing is the most likely >>> target. That gets them to 10 us max and< 1 us typical. Of course somebody >>> would have to buy the gear to actually *use* it to do any good... (yes I >>> could and have gone on and on about that topic). >> >> Well, they do actually regulate telecoms, so they may simply be told that >> it will be a condition for their licenses. >> >> That happened with respect to power backups for cellular towers >> after Katrina showed the inadequacy of 3 hours lead-acid backup. >> > > > ___ > time-nuts mailing list -- time-nuts@febo.com > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Loran in the US
On 03/08/2012 11:21 PM, Bob Camp wrote: Hi Should be *very* interesting to watch if they try to legislate something like that... Indeed. There are different telecom needs. CDMA isn't everything. SDH/SONET goes under G.811, meaning within 1E-11 in frequency. GSM should be within +/- 50 ppb, but long-term should be like SDH/SONET. etc. etc. Cheers, Magnus Bob -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Poul-Henning Kamp Sent: Thursday, March 08, 2012 5:10 PM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] Loran in the US In message, "Bob Camp" writes: If they are backing up GPS for telcom, then CDMA timing is the most likely target. That gets them to 10 us max and< 1 us typical. Of course somebody would have to buy the gear to actually *use* it to do any good... (yes I could and have gone on and on about that topic). Well, they do actually regulate telecoms, so they may simply be told that it will be a condition for their licenses. That happened with respect to power backups for cellular towers after Katrina showed the inadequacy of 3 hours lead-acid backup. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Loran in the US
Hi Should be *very* interesting to watch if they try to legislate something like that... Bob -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Poul-Henning Kamp Sent: Thursday, March 08, 2012 5:10 PM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] Loran in the US In message , "Bob Camp" writes: >If they are backing up GPS for telcom, then CDMA timing is the most likely >target. That gets them to 10 us max and < 1 us typical. Of course somebody >would have to buy the gear to actually *use* it to do any good... (yes I >could and have gone on and on about that topic). Well, they do actually regulate telecoms, so they may simply be told that it will be a condition for their licenses. That happened with respect to power backups for cellular towers after Katrina showed the inadequacy of 3 hours lead-acid backup. -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 p...@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@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Loran in the US
In message , "Bob Camp" writes: >If they are backing up GPS for telcom, then CDMA timing is the most likely >target. That gets them to 10 us max and < 1 us typical. Of course somebody >would have to buy the gear to actually *use* it to do any good... (yes I >could and have gone on and on about that topic). Well, they do actually regulate telecoms, so they may simply be told that it will be a condition for their licenses. That happened with respect to power backups for cellular towers after Katrina showed the inadequacy of 3 hours lead-acid backup. -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 p...@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@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Loran in the US
Hi If they are backing up GPS for telcom, then CDMA timing is the most likely target. That gets them to 10 us max and < 1 us typical. Of course somebody would have to buy the gear to actually *use* it to do any good... (yes I could and have gone on and on about that topic). Bob -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Poul-Henning Kamp Sent: Thursday, March 08, 2012 2:58 AM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] Loran in the US Has anybody asked them how good time&freq they're trying to deliver ? I would assume that they are aiming for a backup for GPS in telecom-GPSDO context. If so, frequency stability is priority number one and time is probably just "better than 100msec" or so -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 p...@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@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Loran in the US
Has anybody asked them how good time&freq they're trying to deliver ? I would assume that they are aiming for a backup for GPS in telecom-GPSDO context. If so, frequency stability is priority number one and time is probably just "better than 100msec" or so -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 p...@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@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Loran in the US
Multipath propagation issues? http://en.wikipedia.org/wiki/Multipath_propagation We can certainly throw computational power against that wall but I think that this would be an issue for TV stations. AM should be better DaveH > -Original Message- > From: time-nuts-boun...@febo.com > [mailto:time-nuts-boun...@febo.com] On Behalf Of Chris Albertson > Sent: Monday, March 05, 2012 9:27 AM > To: Discussion of precise time and frequency measurement > Subject: Re: [time-nuts] Loran in the US > > The best and by far lowest cost solution is to pay TV stations and > maybe AM broadcast stations to add a timing pulse a few times per > second. No transmitters to build. The receivers would be more > complete but that is OK in 2012. In the "old days" it was to > expensive to put a complex computer inside a radio but now that is > routine.So I can imagine a receivers that can listen to 20 or 30 > broadcast stations, look of the latitude and longitude of each one and > compute a best fit to the delays. Actually that is how GPS works but > only in L1 > > Traditionally the main problem with using comercail radios for > navigation has been then they don't issue a station ID frequenty > enough so you have to listen for a long time to know what station > you've tuned. But radio with a computer inside would know the > station by it's frequency and the approx. location of the receiver. > > > On Sun, Mar 4, 2012 at 1:02 PM, Charles P. Steinmetz > wrote: > > Antonio wrote: > > > >> Now, that the Loran C ressurection seems to be probable > > > > > > I suspect that it is not yet anywhere near probable -- more > likely there is > > now some remote possibility of a ressurection if many difficult > > preconditions (including Congressional action) are all met. > > > > Best regards, > > > > Charles > > > > > > > > > > > > > > > > ___ > > time-nuts mailing list -- time-nuts@febo.com > > To unsubscribe, go to > > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > > and follow the instructions there. > > > > -- > > Chris Albertson > Redondo Beach, California > > ___ > time-nuts mailing list -- time-nuts@febo.com > To unsubscribe, go to > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Loran in the US
On 3/5/12 9:26 AM, Chris Albertson wrote: The best and by far lowest cost solution is to pay TV stations and maybe AM broadcast stations to add a timing pulse a few times per second. I suppose you could do this by the FM subcarrier broadcast approach, too.. just like they used to distribute stock quotes, sports scores, and GPS differential corrections. Or, you could use pager transmissions. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Loran in the US
Hy Chris, Here you can find something usefull. http://www.bipm.org/en/si/si_brochure/ in french: membres.multimania.fr/f1rhr/jms/rxetalon.pdf www.datelec.fr/signaux_horaires/p0.htm regards F4GBC -Message d'origine- From: Chris Albertson Sent: Monday, March 05, 2012 8:27 PM To: j...@quikus.com ; Discussion of precise time and frequency measurement Subject: Re: [time-nuts] Loran in the US On Mon, Mar 5, 2012 at 10:09 AM, J. Forster wrote: Already been done, and patented, without adding pulses to existing AM stations. Would you happen you know the patent number or something else I could use to do a search on it? I know some one who is working on this. I'd like to be able to point out what's already been done and patented. The best and by far lowest cost solution is to pay TV stations and maybe AM broadcast stations to add a timing pulse a few times per Chris Albertson Redondo Beach, California ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Loran in the US
Hi Ok, that's more information than we had before about what they are trying to do. Precise timing sounds like a good thing for them to work on :)... Bob -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Greg Broburg Sent: Monday, March 05, 2012 2:19 PM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] Loran in the US Reply to Keith Peshak from Chris Stout. > As of now, we don't currently have a schedule for when we will be back on-air. Because we are testing precise timing capabilities under the CRADA, we are only broadcasting from one station which is all that is necessary for disseminating timing information. We currently don't have any plans to broadcast from multiple stations which is what you would need for your navigation testing but I will let you know if we happen to be on-air from multiple stations in the future. > > Thanks for your continued interest and support in Low Frequency signals! > > Chris ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Loran in the US
On 03/05/2012 03:40 PM, John Ackermann N8UR wrote: An interesting complexity of any new Loran system is that it won't be able to rely on GPS for time synchronization! There is nothing wrong with using GPS WHEN it works, but one has to check if it is not reliable such that one can cut off the dependence in time. I still want to see the GPS receiver which pulls it off properly. Cheers, Magnus ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Loran in the US
> > 5. Counselman Charles C III, Hall Timothy D: Instantaneous radiopositioning > using signals of opportunity. Massachusetts Institute of Technology Jul, 25 > 2002: WO 2002/057806 > That is an incredibly interesting patent. Thanks for the reference. Peter K1PGV ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Loran in the US
5. Counselman Charles C III, Hall Timothy D: Instantaneous radiopositioning using signals of opportunity. Massachusetts Institute of Technology Jul, 25 2002: WO 2002/057806 -John == > On Mon, Mar 5, 2012 at 10:09 AM, J. Forster wrote: >> Already been done, and patented, without adding pulses to existing AM >> stations. > > > Would you happen you know the patent number or something else I could > use to do a search on it? I know some one who is working on this. > I'd like to be able to point out what's already been done and > patented. > > >>> The best and by far lowest cost solution is to pay TV stations and >>> maybe AM broadcast stations to add a timing pulse a few times per > Chris Albertson > Redondo Beach, California > > ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Loran in the US
On Mon, Mar 5, 2012 at 10:09 AM, J. Forster wrote: > Already been done, and patented, without adding pulses to existing AM > stations. Would you happen you know the patent number or something else I could use to do a search on it? I know some one who is working on this. I'd like to be able to point out what's already been done and patented. >> The best and by far lowest cost solution is to pay TV stations and >> maybe AM broadcast stations to add a timing pulse a few times per Chris Albertson Redondo Beach, California ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Loran in the US
Reply to Keith Peshak from Chris Stout. As of now, we don't currently have a schedule for when we will be back on-air. Because we are testing precise timing capabilities under the CRADA, we are only broadcasting from one station which is all that is necessary for disseminating timing information. We currently don't have any plans to broadcast from multiple stations which is what you would need for your navigation testing but I will let you know if we happen to be on-air from multiple stations in the future. Thanks for your continued interest and support in Low Frequency signals! Chris ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Loran in the US
Already been done, and patented, without adding pulses to existing AM stations. -John == > The best and by far lowest cost solution is to pay TV stations and > maybe AM broadcast stations to add a timing pulse a few times per > second. No transmitters to build. The receivers would be more > complete but that is OK in 2012. In the "old days" it was to > expensive to put a complex computer inside a radio but now that is > routine.So I can imagine a receivers that can listen to 20 or 30 > broadcast stations, look of the latitude and longitude of each one and > compute a best fit to the delays. Actually that is how GPS works but > only in L1 > > Traditionally the main problem with using comercail radios for > navigation has been then they don't issue a station ID frequenty > enough so you have to listen for a long time to know what station > you've tuned. But radio with a computer inside would know the > station by it's frequency and the approx. location of the receiver. > > > On Sun, Mar 4, 2012 at 1:02 PM, Charles P. Steinmetz > wrote: >> Antonio wrote: >> >>> Now, that the Loran C ressurection seems to be probable >> >> >> I suspect that it is not yet anywhere near probable -- more likely there >> is >> now some remote possibility of a ressurection if many difficult >> preconditions (including Congressional action) are all met. >> >> Best regards, >> >> Charles >> >> >> >> >> >> >> >> ___ >> time-nuts mailing list -- time-nuts@febo.com >> To unsubscribe, go to >> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts >> and follow the instructions there. > > > > -- > > Chris Albertson > Redondo Beach, California > > ___ > time-nuts mailing list -- time-nuts@febo.com > To unsubscribe, go to > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. > > ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Loran in the US
If the old antennas are still in good shape, why not use them? The post suggesting a LightSquared involvement is interesting. Suppose LightSquared paid for a LORAN system to eliminate some opposition to the deployment of their wifi network? -John === > Hi > > If you are doing a "light footprint" system, why fire up the old heavy > footprint gear at all? > > Bob > > -Original Message- > From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On > Behalf Of J. Forster > Sent: Monday, March 05, 2012 10:40 AM > To: Discussion of precise time and frequency measurement > Subject: Re: [time-nuts] Loran in the US > > A "light footprint" LORAN is what I've been suggesting for several days. > > As to putting it into private hands, there is a potential for massive > finmancial fraud in market arbitrage. It was only a couple of weeks ago > that this made headlines with GPS timing. > > -John > > = > > > >> In message <20120305113804.48fc411b...@karen.lavabit.com>, "Charles P. >> Steinmet >> z" writes: >> >>>Technical merit aside, I doubt there is any chance of getting >>>regulatory approval for such a system, at least in the US, for >>>practical and political reasons. >> >> Indeed, it's absolutely out of the question, as you well know all >> our problems these days are there isn't enough God in the constitution >> or something. >> >> Thats why some people in the military is looking into a modern >> more lightweight version of "Tactical Loran" for use when GPS is jammed. >> >> -- >> Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 >> p...@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@febo.com >> To unsubscribe, go to >> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts >> and follow the instructions there. >> >> > > > > ___ > time-nuts mailing list -- time-nuts@febo.com > To unsubscribe, go to > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. > > ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Loran in the US
The best and by far lowest cost solution is to pay TV stations and maybe AM broadcast stations to add a timing pulse a few times per second. No transmitters to build. The receivers would be more complete but that is OK in 2012. In the "old days" it was to expensive to put a complex computer inside a radio but now that is routine.So I can imagine a receivers that can listen to 20 or 30 broadcast stations, look of the latitude and longitude of each one and compute a best fit to the delays. Actually that is how GPS works but only in L1 Traditionally the main problem with using comercail radios for navigation has been then they don't issue a station ID frequenty enough so you have to listen for a long time to know what station you've tuned. But radio with a computer inside would know the station by it's frequency and the approx. location of the receiver. On Sun, Mar 4, 2012 at 1:02 PM, Charles P. Steinmetz wrote: > Antonio wrote: > >> Now, that the Loran C ressurection seems to be probable > > > I suspect that it is not yet anywhere near probable -- more likely there is > now some remote possibility of a ressurection if many difficult > preconditions (including Congressional action) are all met. > > Best regards, > > Charles > > > > > > > > ___ > time-nuts mailing list -- time-nuts@febo.com > To unsubscribe, go to > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. -- Chris Albertson Redondo Beach, California ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Loran in the US
Hi If you are doing a "light footprint" system, why fire up the old heavy footprint gear at all? Bob -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of J. Forster Sent: Monday, March 05, 2012 10:40 AM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] Loran in the US A "light footprint" LORAN is what I've been suggesting for several days. As to putting it into private hands, there is a potential for massive finmancial fraud in market arbitrage. It was only a couple of weeks ago that this made headlines with GPS timing. -John = > In message <20120305113804.48fc411b...@karen.lavabit.com>, "Charles P. > Steinmet > z" writes: > >>Technical merit aside, I doubt there is any chance of getting >>regulatory approval for such a system, at least in the US, for >>practical and political reasons. > > Indeed, it's absolutely out of the question, as you well know all > our problems these days are there isn't enough God in the constitution > or something. > > Thats why some people in the military is looking into a modern > more lightweight version of "Tactical Loran" for use when GPS is jammed. > > -- > Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 > p...@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@febo.com > To unsubscribe, go to > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. > > ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Loran in the US
A woman is waiting outside of the operating room for news of her husbands fate. After some hours of waiting a physician comes to her and in a soft voice gives her the news that he has passed. The situation at hand was that the paperwork was beyond the operating teams capabilities. We will learn, I hope sometime in the near future, what the written permissions will be for this Loran experiment. My bet is that there is a desire for backup precision marine navigation around port cities where LightSquared will find most of its customers. This implies LightSquareds financial and political base are a force to discard GPS performance in these ports. So it would seem to me that the Coast Guard sees the investment as a necessary retrenchment to their original move to abandon Loran to the FAA many years ago. Greg On 3/5/2012 8:37 AM, Jim Lux wrote: On 3/5/12 6:19 AM, Charles P. Steinmetz wrote: Poul-Henning wrote: Thats why some people in the military is looking into a modern more lightweight version of "Tactical Loran" for use when GPS is jammed. That is a much easier thing -- our military/intelligence complex (however oxymoronic that notion is) tries very hard to keep its engagements well away from US soil, so (i) no regulatory approval is required As someone who deals with non-FCC regulatory approval on a fairly frequent basis, I can tell you it's not quite that simple. If you're the US government, you're regulated by NTIA, which works much like FCC for licensing. You have to tell where and when and what sort of emissions, where and when and what sort of receivers, get permission, etc. And if you're planning on operating outside the US, that gets coordinated via some ITU process. This is a HUGE problem for the plethora of colleges, businesses, and government labs and research institutions jumping on the nanosat and cubesat bandwagon. Their operations don't really fit within the "amateur radio" bucket, where licensing is fairly easy. and (ii) the geographic area of the operating theater is usually far smaller than the size of the US. So, we may very well see the development of mobile beacons for military deployment in hostile areas, but I very much doubt that we will ever see another terrestrial beacon system in the US. Perhaps not a unified one, but I can see a variety of proprietary or private locating networks being set up. Surveyors already have high accuracy reference networks. Some are state run, but others are run by consortiums or private parties. 20 years ago, you used to be able to subscribe to a private service that would give you differential corrections for GPS via a FM broadcast subcarrier or pager. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Loran in the US
On 3/5/2012 10:13 AM, Poul-Henning Kamp wrote: In message<4f54d075.6070...@febo.com>, John Ackermann N8UR writes: An interesting complexity of any new Loran system is that it won't be able to rely on GPS for time synchronization! Well, define "rely". If they're using a Cs and GPS-steer that when there is good GPS, I don't see much of a problem. If the claim is "independent of GPS" any reliance on GPS in the system would be troublesome. But I'll admit we don't know yet what the stated goal of the system is... ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Loran in the US
A "light footprint" LORAN is what I've been suggesting for several days. As to putting it into private hands, there is a potential for massive finmancial fraud in market arbitrage. It was only a couple of weeks ago that this made headlines with GPS timing. -John = > In message <20120305113804.48fc411b...@karen.lavabit.com>, "Charles P. > Steinmet > z" writes: > >>Technical merit aside, I doubt there is any chance of getting >>regulatory approval for such a system, at least in the US, for >>practical and political reasons. > > Indeed, it's absolutely out of the question, as you well know all > our problems these days are there isn't enough God in the constitution > or something. > > Thats why some people in the military is looking into a modern > more lightweight version of "Tactical Loran" for use when GPS is jammed. > > -- > Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 > p...@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@febo.com > To unsubscribe, go to > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. > > ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Loran in the US
In message <4f54d075.6070...@febo.com>, John Ackermann N8UR writes: >An interesting complexity of any new Loran system is that it won't be >able to rely on GPS for time synchronization! Well, define "rely". If they're using a Cs and GPS-steer that when there is good GPS, I don't see much of a problem. -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 p...@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@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Loran in the US
An interesting complexity of any new Loran system is that it won't be able to rely on GPS for time synchronization! John ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Loran in the US
On 3/5/12 6:19 AM, Charles P. Steinmetz wrote: Poul-Henning wrote: Thats why some people in the military is looking into a modern more lightweight version of "Tactical Loran" for use when GPS is jammed. That is a much easier thing -- our military/intelligence complex (however oxymoronic that notion is) tries very hard to keep its engagements well away from US soil, so (i) no regulatory approval is required As someone who deals with non-FCC regulatory approval on a fairly frequent basis, I can tell you it's not quite that simple. If you're the US government, you're regulated by NTIA, which works much like FCC for licensing. You have to tell where and when and what sort of emissions, where and when and what sort of receivers, get permission, etc. And if you're planning on operating outside the US, that gets coordinated via some ITU process. This is a HUGE problem for the plethora of colleges, businesses, and government labs and research institutions jumping on the nanosat and cubesat bandwagon. Their operations don't really fit within the "amateur radio" bucket, where licensing is fairly easy. and (ii) the geographic area of the operating theater is usually far smaller than the size of the US. So, we may very well see the development of mobile beacons for military deployment in hostile areas, but I very much doubt that we will ever see another terrestrial beacon system in the US. Perhaps not a unified one, but I can see a variety of proprietary or private locating networks being set up. Surveyors already have high accuracy reference networks. Some are state run, but others are run by consortiums or private parties. 20 years ago, you used to be able to subscribe to a private service that would give you differential corrections for GPS via a FM broadcast subcarrier or pager. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Loran in the US
On 3/5/12 3:45 AM, Poul-Henning Kamp wrote: In message<20120305113804.48fc411b...@karen.lavabit.com>, "Charles P. Steinmet z" writes: Technical merit aside, I doubt there is any chance of getting regulatory approval for such a system, at least in the US, for practical and political reasons. Indeed, it's absolutely out of the question, as you well know all our problems these days are there isn't enough God in the constitution or something. Thats why some people in the military is looking into a modern more lightweight version of "Tactical Loran" for use when GPS is jammed. What about the Locata folks? That's a tactical GPS replacement of sorts.. precision position and time over a small area (or indoors). BTW, I think the idea of using PN coded LF or VLF signals is a good one. These days, doing the correlation and such is fairly easy. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Loran in the US
On 3/5/12 2:31 AM, Charles P. Steinmetz wrote: Poul-Henning wrote: That would make roll-out a matter not for governments, but for airports, harbours and other interested parties, like for instance DME. Would this mean depending on private parties for precision timing and positioning [using that particular system, of course]? If so, I'm not sure that is such a good idea. Some endeavors do not lend themselves readily to distributed responsibility But this kind of thing already exists in some ways. Consider that you hire a private party (a licensed surveyor) to establish property boundaries and such. Yes, the surveyor has a legal obligation to report their findings to the government (to the county recorder), but I've noticed that this isn't always the case. And until GPS came around, the government was happy to establish a place where you could go and compare your clock to an official clock, they didn't feel obligated to dstribute time and frequency at high accuracy. (Where WWV isn't "high accuracy") There's also ARINC, which is a private consortium owned mostly by air line companies (I think) to provide communications and nav services to airliners. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Loran in the US
Poul-Henning wrote: Thats why some people in the military is looking into a modern more lightweight version of "Tactical Loran" for use when GPS is jammed. That is a much easier thing -- our military/intelligence complex (however oxymoronic that notion is) tries very hard to keep its engagements well away from US soil, so (i) no regulatory approval is required and (ii) the geographic area of the operating theater is usually far smaller than the size of the US. So, we may very well see the development of mobile beacons for military deployment in hostile areas, but I very much doubt that we will ever see another terrestrial beacon system in the US. Best regards, Charles ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Loran in the US
In message <20120305113804.48fc411b...@karen.lavabit.com>, "Charles P. Steinmet z" writes: >Technical merit aside, I doubt there is any chance of getting >regulatory approval for such a system, at least in the US, for >practical and political reasons. Indeed, it's absolutely out of the question, as you well know all our problems these days are there isn't enough God in the constitution or something. Thats why some people in the military is looking into a modern more lightweight version of "Tactical Loran" for use when GPS is jammed. -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 p...@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@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Loran in the US
Poul-Henning wrote (regarding the possibility of advanced, private Loran-like systems): Well, that could be your own choice, you can tell your receiver which transmitters you trust. That presumes (i) substantial sophistication on the part of the user and (ii) possession of data that would be very hard to gather reliably (or to trust, if popularly disseminated) -- neither of which may be justified for the vast majority of users. Technical merit aside, I doubt there is any chance of getting regulatory approval for such a system, at least in the US, for practical and political reasons. Best regards, Charles ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Loran in the US
In message <20120305103136.7e0f511b...@karen.lavabit.com>, "Charles P. Steinmet z" writes: >Poul-Henning wrote: > >>That would make roll-out a matter not for governments, but for >>airports, harbours and other interested parties, like for instance >>DME. > >Would this mean depending on private parties for precision timing and >positioning [using that particular system, of course]? Well, that could be your own choice, you can tell your receiver which transmitters you trust. -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 p...@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@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Loran in the US
Poul-Henning wrote: That would make roll-out a matter not for governments, but for airports, harbours and other interested parties, like for instance DME. Would this mean depending on private parties for precision timing and positioning [using that particular system, of course]? If so, I'm not sure that is such a good idea. Some endeavors do not lend themselves readily to distributed responsibility Best regards, Charles ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Loran in the US
I agree. On Mon, Mar 5, 2012 at 10:24 AM, Poul-Henning Kamp wrote: > In message , Bob Camp > writes: > > >You still come back to what killer Loran-C in the first place - > >Who is going to use it? > > No, I don't particularly think Loran-C is a "killer", but until recently > it was the only feasilble backup for fragile GNSS signals. > > >Until somebody shuts down GPS in a big way, not a lot of drive for > >an alternative. > > I agree, but that doesn't make it sensible thinking :-) > > I think the LightSquared fiasco made some people realize how many > eggs they put in one basket, and I'm sure the Loran-C tests needs > to be seen in that context. > > But that doesn't make them a good idea: Resurrecting LORAN-C now > will never make it an economical backup to GNSS. > > Instead of insisting on keeping an on-air format optimised for > staring at 1950-vintage oscilloscopes, what we need is a VLF system, > in sub/low kW power-range, based on spread-spectrum technology, with a > data-channel so receivers don't have to have a hard coded list > of all transmitters. > > That would make roll-out a matter not for governments, but for > airports, harbours and other interested parties, like for instance > DME. > > -- > Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 > p...@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@febo.com > To unsubscribe, go to > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. > ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Loran in the US
In message , Bob Camp writes: >You still come back to what killer Loran-C in the first place - >Who is going to use it? No, I don't particularly think Loran-C is a "killer", but until recently it was the only feasilble backup for fragile GNSS signals. >Until somebody shuts down GPS in a big way, not a lot of drive for >an alternative. I agree, but that doesn't make it sensible thinking :-) I think the LightSquared fiasco made some people realize how many eggs they put in one basket, and I'm sure the Loran-C tests needs to be seen in that context. But that doesn't make them a good idea: Resurrecting LORAN-C now will never make it an economical backup to GNSS. Instead of insisting on keeping an on-air format optimised for staring at 1950-vintage oscilloscopes, what we need is a VLF system, in sub/low kW power-range, based on spread-spectrum technology, with a data-channel so receivers don't have to have a hard coded list of all transmitters. That would make roll-out a matter not for governments, but for airports, harbours and other interested parties, like for instance DME. -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 p...@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@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Loran in the US
Hi You still come back to what killer Loran-C in the first place - Who is going to use it? Until somebody shuts down GPS in a big way, not a lot of drive for an alternative. I not saying that is a well thought out situation. It is indeed the position everybody has taken. It is a classic cost / risk issue. Cost is known, risk is assumed to be low / zero... Bob On Mar 4, 2012, at 5:50 PM, "Poul-Henning Kamp" wrote: > In message <57034.12.6.201.2.1330897195.squir...@popaccts.quikus.com>, "J. > Fors > ter" writes: > >> One option might be more, smaller, cheaper stations. > > At one point, a LORAN-X (for some value of X > D) was proposed which > would use ~1kW transmitters with PRNG codes at 100kHz and give vastly > better results than LORAN-C. > > It's mentioned somewhere in the ILA's archives, probably early '80ies. > > The idea has been partially validated by DCF77's phase-coding. > > > -- > Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 > p...@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@febo.com > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Loran in the US
In message <57034.12.6.201.2.1330897195.squir...@popaccts.quikus.com>, "J. Fors ter" writes: >One option might be more, smaller, cheaper stations. At one point, a LORAN-X (for some value of X > D) was proposed which would use ~1kW transmitters with PRNG codes at 100kHz and give vastly better results than LORAN-C. It's mentioned somewhere in the ILA's archives, probably early '80ies. The idea has been partially validated by DCF77's phase-coding. -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 p...@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@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Loran in the US
Look at it from a politician's point of view: Would you really want to admit that your government screwed up and destroyed a working, but old, system, and now you find you need it as a backup to GPS? Or, would you rather build a shiney, new, "state of the art" system, which just happend to be compatible with legacy systems that many people have, but offers "enhanced" bells and whistles? Or, would you prefer to do nothing, although the problem is widely known, and then be hung when a disaster strikes? -John == > Hi > > The gotcha with a non compatible coding is cross chain interference. My > guess is that those who are currently running Loran-C would be a bit > bothered if the "new" system nuked there ability to navigate any time > skywave propigation was present. The current coding and repetition rates > took a while to work out. It would be much easier to enhance the old US > chain rates than to do something entirely new. > > As I said before - this could indeed be wishful thinking on my part. I > have yet to see anything in print describing what the compelling reason > for firing all this up actually is. Obviously the vendors want to sell > gear, past that not very clear at all... > > Bob > > On Mar 4, 2012, at 4:34 PM, Magnus Danielson wrote: > >> On 03/04/2012 10:02 PM, Charles P. Steinmetz wrote: >>> Antonio wrote: >>> Now, that the Loran C ressurection seems to be probable >>> >>> I suspect that it is not yet anywhere near probable -- more likely >>> there >>> is now some remote possibility of a ressurection if many difficult >>> preconditions (including Congressional action) are all met. >> >> Rebuilding the network and finance the cost of running it will be a >> challenge. This is why tearing down the old network was such a waste of >> money. If they seriously considers it, maybe they have learned a hard >> lesson and at least considers it and is ready to bite the bullet. >> >> A key worry would be if they chose to use a non-compatible coding such >> that existing Loran-C equipment needs to be scrapped anyway. >> >> It would be interesting to see how it plays out. >> >> Cheers, >> Magnus >> >> ___ >> time-nuts mailing list -- time-nuts@febo.com >> To unsubscribe, go to >> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts >> and follow the instructions there. > > > ___ > time-nuts mailing list -- time-nuts@febo.com > To unsubscribe, go to > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. > > ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Loran in the US
Hi The gotcha with a non compatible coding is cross chain interference. My guess is that those who are currently running Loran-C would be a bit bothered if the "new" system nuked there ability to navigate any time skywave propigation was present. The current coding and repetition rates took a while to work out. It would be much easier to enhance the old US chain rates than to do something entirely new. As I said before - this could indeed be wishful thinking on my part. I have yet to see anything in print describing what the compelling reason for firing all this up actually is. Obviously the vendors want to sell gear, past that not very clear at all... Bob On Mar 4, 2012, at 4:34 PM, Magnus Danielson wrote: > On 03/04/2012 10:02 PM, Charles P. Steinmetz wrote: >> Antonio wrote: >> >>> Now, that the Loran C ressurection seems to be probable >> >> I suspect that it is not yet anywhere near probable -- more likely there >> is now some remote possibility of a ressurection if many difficult >> preconditions (including Congressional action) are all met. > > Rebuilding the network and finance the cost of running it will be a > challenge. This is why tearing down the old network was such a waste of > money. If they seriously considers it, maybe they have learned a hard lesson > and at least considers it and is ready to bite the bullet. > > A key worry would be if they chose to use a non-compatible coding such that > existing Loran-C equipment needs to be scrapped anyway. > > It would be interesting to see how it plays out. > > Cheers, > Magnus > > ___ > time-nuts mailing list -- time-nuts@febo.com > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Loran in the US
Even with yesterday's electronics, many Loran stations outside the US were operating under remote control, with a single control station managing multiple chains. --Glen At 03:39 PM 3/4/2012, you wrote: With today's electronics and 'puters, a new system could be designed to operate essentially without local staffing, IMO. The biggest problem would be getting antennas with reasonable radiation efficiency at 100 kHz, without using 1000' plus towers. One option might be more, smaller, cheaper stations. -John = > On 03/04/2012 10:02 PM, Charles P. Steinmetz wrote: >> Antonio wrote: >> >>> Now, that the Loran C ressurection seems to be probable >> >> I suspect that it is not yet anywhere near probable -- more likely there >> is now some remote possibility of a ressurection if many difficult >> preconditions (including Congressional action) are all met. > > Rebuilding the network and finance the cost of running it will be a > challenge. This is why tearing down the old network was such a waste of > money. If they seriously considers it, maybe they have learned a hard > lesson and at least considers it and is ready to bite the bullet. > > A key worry would be if they chose to use a non-compatible coding such > that existing Loran-C equipment needs to be scrapped anyway. > > It would be interesting to see how it plays out. > > Cheers, > Magnus > > ___ > time-nuts mailing list -- time-nuts@febo.com > To unsubscribe, go to > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. > > ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Loran in the US
With today's electronics and 'puters, a new system could be designed to operate essentially without local staffing, IMO. The biggest problem would be getting antennas with reasonable radiation efficiency at 100 kHz, without using 1000' plus towers. One option might be more, smaller, cheaper stations. -John = > On 03/04/2012 10:02 PM, Charles P. Steinmetz wrote: >> Antonio wrote: >> >>> Now, that the Loran C ressurection seems to be probable >> >> I suspect that it is not yet anywhere near probable -- more likely there >> is now some remote possibility of a ressurection if many difficult >> preconditions (including Congressional action) are all met. > > Rebuilding the network and finance the cost of running it will be a > challenge. This is why tearing down the old network was such a waste of > money. If they seriously considers it, maybe they have learned a hard > lesson and at least considers it and is ready to bite the bullet. > > A key worry would be if they chose to use a non-compatible coding such > that existing Loran-C equipment needs to be scrapped anyway. > > It would be interesting to see how it plays out. > > Cheers, > Magnus > > ___ > time-nuts mailing list -- time-nuts@febo.com > To unsubscribe, go to > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. > > ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Loran in the US
On 03/04/2012 10:02 PM, Charles P. Steinmetz wrote: Antonio wrote: Now, that the Loran C ressurection seems to be probable I suspect that it is not yet anywhere near probable -- more likely there is now some remote possibility of a ressurection if many difficult preconditions (including Congressional action) are all met. Rebuilding the network and finance the cost of running it will be a challenge. This is why tearing down the old network was such a waste of money. If they seriously considers it, maybe they have learned a hard lesson and at least considers it and is ready to bite the bullet. A key worry would be if they chose to use a non-compatible coding such that existing Loran-C equipment needs to be scrapped anyway. It would be interesting to see how it plays out. Cheers, Magnus ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Loran in the US
Antonio wrote: Now, that the Loran C ressurection seems to be probable I suspect that it is not yet anywhere near probable -- more likely there is now some remote possibility of a ressurection if many difficult preconditions (including Congressional action) are all met. Best regards, Charles ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
