Re: [time-nuts] Loran in the US

2012-03-09 Thread Poul-Henning Kamp
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

Re: [time-nuts] Loran in the US

2012-03-09 Thread Bob Camp
...@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

Re: [time-nuts] Loran in the US

2012-03-08 Thread Bob Camp
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 timefreq they're

Re: [time-nuts] Loran in the US

2012-03-08 Thread Poul-Henning Kamp
In message d20d95b53d5c40f5aca05df98fdb9...@vectron.com, 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

Re: [time-nuts] Loran in the US

2012-03-08 Thread Bob Camp
and frequency measurement Subject: Re: [time-nuts] Loran in the US In message d20d95b53d5c40f5aca05df98fdb9...@vectron.com, 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

Re: [time-nuts] Loran in the US

2012-03-08 Thread Magnus Danielson
Subject: Re: [time-nuts] Loran in the US In messaged20d95b53d5c40f5aca05df98fdb9...@vectron.com, 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

Re: [time-nuts] Loran in the US

2012-03-08 Thread Bob Camp
: Thursday, March 08, 2012 5:10 PM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] Loran in the US In messaged20d95b53d5c40f5aca05df98fdb9...@vectron.com, Bob Camp writes: If they are backing up GPS for telcom, then CDMA timing is the most likely target. That gets

Re: [time-nuts] Loran in the US

2012-03-08 Thread Magnus Danielson
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

Re: [time-nuts] Loran in the US

2012-03-08 Thread Bob Camp
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 mag...@rubidium.dyndns.org wrote: On 03/09/2012 12:16 AM, Bob Camp wrote: Hi SDH/SONET generally is line timed rather than GPS locked. It's

Re: [time-nuts] Loran in the US

2012-03-08 Thread Dennis Ferguson
On 8 Mar, 2012, at 02:58 , Poul-Henning Kamp wrote: Has anybody asked them how good timefreq 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

Re: [time-nuts] Loran in the US

2012-03-07 Thread DaveH
[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

Re: [time-nuts] Loran in the US

2012-03-07 Thread Poul-Henning Kamp
Has anybody asked them how good timefreq 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

Re: [time-nuts] Loran in the US

2012-03-06 Thread Alain2_4GBC
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 j...@quikus.com wrote: Already been done, and patented, without adding pulses to existing AM stations. Would you happen you know

Re: [time-nuts] Loran in the US

2012-03-05 Thread Poul-Henning Kamp
In message f5c81892-7ebd-4f57-8131-59d8eee21...@rtty.us, 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.

Re: [time-nuts] Loran in the US

2012-03-05 Thread Azelio Boriani
I agree. On Mon, Mar 5, 2012 at 10:24 AM, Poul-Henning Kamp p...@phk.freebsd.dkwrote: In message f5c81892-7ebd-4f57-8131-59d8eee21...@rtty.us, 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

Re: [time-nuts] Loran in the US

2012-03-05 Thread Charles P. Steinmetz
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

Re: [time-nuts] Loran in the US

2012-03-05 Thread Poul-Henning Kamp
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

Re: [time-nuts] Loran in the US

2012-03-05 Thread Charles P. Steinmetz
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

Re: [time-nuts] Loran in the US

2012-03-05 Thread Poul-Henning Kamp
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

Re: [time-nuts] Loran in the US

2012-03-05 Thread Charles P. Steinmetz
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

Re: [time-nuts] Loran in the US

2012-03-05 Thread Jim Lux
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

Re: [time-nuts] Loran in the US

2012-03-05 Thread Jim Lux
On 3/5/12 3:45 AM, Poul-Henning Kamp wrote: In message20120305113804.48fc411b...@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.

Re: [time-nuts] Loran in the US

2012-03-05 Thread Jim Lux
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

Re: [time-nuts] Loran in the US

2012-03-05 Thread John Ackermann N8UR
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

Re: [time-nuts] Loran in the US

2012-03-05 Thread Poul-Henning Kamp
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

Re: [time-nuts] Loran in the US

2012-03-05 Thread J. Forster
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

Re: [time-nuts] Loran in the US

2012-03-05 Thread John Ackermann N8UR
On 3/5/2012 10:13 AM, Poul-Henning Kamp wrote: In message4f54d075.6070...@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

Re: [time-nuts] Loran in the US

2012-03-05 Thread Greg Broburg
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

Re: [time-nuts] Loran in the US

2012-03-05 Thread Bob Camp
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

Re: [time-nuts] Loran in the US

2012-03-05 Thread Chris Albertson
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

Re: [time-nuts] Loran in the US

2012-03-05 Thread J. Forster
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

Re: [time-nuts] Loran in the US

2012-03-05 Thread J. Forster
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

Re: [time-nuts] Loran in the US

2012-03-05 Thread Greg Broburg
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

Re: [time-nuts] Loran in the US

2012-03-05 Thread Chris Albertson
On Mon, Mar 5, 2012 at 10:09 AM, J. Forster j...@quikus.com 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

Re: [time-nuts] Loran in the US

2012-03-05 Thread J. Forster
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 j...@quikus.com wrote: Already been done, and

Re: [time-nuts] Loran in the US

2012-03-05 Thread Peter G. Viscarola
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

Re: [time-nuts] Loran in the US

2012-03-05 Thread Magnus Danielson
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

Re: [time-nuts] Loran in the US

2012-03-05 Thread Bob Camp
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

Re: [time-nuts] Loran in the US

2012-03-04 Thread Charles P. Steinmetz
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,

Re: [time-nuts] Loran in the US

2012-03-04 Thread Magnus Danielson
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

Re: [time-nuts] Loran in the US

2012-03-04 Thread J. Forster
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

Re: [time-nuts] Loran in the US

2012-03-04 Thread Bob Camp
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

Re: [time-nuts] Loran in the US

2012-03-04 Thread J. Forster
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

Re: [time-nuts] Loran in the US

2012-03-04 Thread Poul-Henning Kamp
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

Re: [time-nuts] Loran in the US

2012-03-04 Thread Bob Camp
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