Re: [time-nuts] WWV and legal issues
Am 01.09.2018 um 20:40 schrieb Magnus Danielson: One should first know that there is a lot of papers now on frequency transfer over fiber. The stability achieved on the best ones so far greatly below that of the optical clocks that they want to compare. Please, in a nutshell: what are the worst offenders: - tranceivers (mechanical, temp, other misfeatures) - cables ( bending, temp, mechanical stress) - others? In the case of transceivers: are there desirable modifications that would alleviate the problems? best regards, Gerhard ___ 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.
Re: [time-nuts] WWV and legal issues
Hi Bob, Thanks for the paper. One should first know that there is a lot of papers now on frequency transfer over fiber. The stability achieved on the best ones so far greatly below that of the optical clocks that they want to compare. Then, for those links able to transfer phase/time, most of them is for point-to-point systems, many relating to relatively short distances. Only a few relates to larger distances and some form of network style, mesh. They fill different purposes, and should not be compared between the groups, as it changes widely what is meaningful. I did a presentation some EFTFs ago on some experiences of time-transfer systems. We had some "interesting" failures where the delay jumped 1 ms. That is what happens when underlying system re-route one side of a two-way transfer under the feet of you. These are challenges others don't see, but that comes with commercial telco setups. For some reason I know far more about behavior and delays in radio links now than I thought I would need to, again for reasons that would never show up in dedicated systems. So, the challenges shifts with the field. Cheers, Magnus On 09/01/2018 08:18 PM, Bob Martin wrote: > > Here is an interesting paper on using fiber: > > https://pdfs.semanticscholar.org/a37e/04164c01a6bfea2154c8f0dd97f49d1673b0.pdf > > > I believe it used some of the gear that is(was) used in the GPS ground > stations around the world. > > Bob Martin > > On 9/1/2018 3:29 AM, Magnus Danielson wrote: >> Hi, >> >> It was very telling when I crashed a research group into the reality of >> phase/time transfer over fiber compared to frequency transfer. Armed >> with a whiteboard and pens, I derived the forumulas and showed how they >> worked and not worked. It's a completely different ball-game and their >> "known tricks" ain't doing nothing good as it comes to time. >> >> I had to figure much of this out myself as I did nation-wide system >> design to achieve the goal. It's a combination of many skills that goes >> into designing the full system from scratch and make it fit together. >> It's not hard stuff, it's just many details one needs to get right. >> >> Oh the fun. >> >> Cheers, >> Magnus >> >> On 08/31/2018 05:15 PM, Bob kb8tq wrote: >>> Hi >>> >>> That works fine if you are doing things manual to check a local >>> standard. If you are trying to >>> disipline a few thousand cell towers 24 hours a day … not so much. It >>> also works for >>> checking frequency. What modern systems need is time. That gets you >>> into a whole >>> world of resolving and identifying individual edges. The WWVB signal >>> really was never >>> set up for this. Loran-C is an example of a signal that was designed >>> to identify a specific >>> edge. >>> >>> Bob >>> On Aug 31, 2018, at 10:30 AM, Martin VE3OAT wrote: But the diurnal phase shifts at VLF are predictable and largely repeatable. Ignore the phase at night and use only the phase records during the day when an all-daylight propagation path exists. You might have to "correct" the absolute phase reading by some multiple of the RF period, but with a low rate of local standard oscillator drift, this is a simple matter of arithmetic. Back in the day, I managed Sulzer crystal oscillators at 5 field sites from my office and could maintain phase continuity for weeks at a time, until we had to diddle the dial on one or several of them to correct for crystal aging. Then it was just more arithmetic again. Several of the oscillators had such low drift rates that all I needed was one daily phase reading from the VLF phase tracking receiver (Tracor 599Js) at those sites to know the frequency of the Sulzers there. ... Martin VE3OAT On Thu, 30 Aug 2018 12:27:12 -0400 Bob kb8tq wrote: > WWVB as transmitted ( = right at the input to the antenna) is a > wonderfully stable signal. As soon as > that signal hits the real world things start to degrade. > Propagation between transmit and receive sites > is a big deal, even at 60 KHz. On top of that, there is a*lot* of > manmade noise at 60 KHz. The receive > signal to noise will never be as good as you might like it to be ?. > I don't know about WWVB, but for DCF77 it's known that sunrise/sunset > causes a phase shift of several 100?s at even moderate distances > (like ~500km). Unfortunately I don't have any measurements at hand. > Attila Kinali ___ 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 >>>
Re: [time-nuts] WWV and legal issues
There was a paper published when NASA did something similar for LC39 and the VAB.Anyone have a copy because the link i have is dead. As I recall it was some trick and compensating for thermal effects on the fiber itself was a large part of the effort. On Sep 1, 2018, at 5:29 AM, Magnus Danielson wrote: Hi, It was very telling when I crashed a research group into the reality of phase/time transfer over fiber compared to frequency transfer. Armed with a whiteboard and pens, I derived the forumulas and showed how they worked and not worked. It's a completely different ball-game and their "known tricks" ain't doing nothing good as it comes to time. I had to figure much of this out myself as I did nation-wide system design to achieve the goal. It's a combination of many skills that goes into designing the full system from scratch and make it fit together. It's not hard stuff, it's just many details one needs to get right. Oh the fun. Cheers, Magnus > On 08/31/2018 05:15 PM, Bob kb8tq wrote: > Hi > > That works fine if you are doing things manual to check a local standard. If > you are trying to > disipline a few thousand cell towers 24 hours a day … not so much. It also > works for > checking frequency. What modern systems need is time. That gets you into a > whole > world of resolving and identifying individual edges. The WWVB signal really > was never > set up for this. Loran-C is an example of a signal that was designed to > identify a specific > edge. > > Bob > >> On Aug 31, 2018, at 10:30 AM, Martin VE3OAT wrote: >> >> But the diurnal phase shifts at VLF are predictable and largely repeatable. >> Ignore the phase at night and use only the phase records during the day when >> an all-daylight propagation path exists. You might have to "correct" the >> absolute phase reading by some multiple of the RF period, but with a low >> rate of local standard oscillator drift, this is a simple matter of >> arithmetic. Back in the day, I managed Sulzer crystal oscillators at 5 field >> sites from my office and could maintain phase continuity for weeks at a >> time, until we had to diddle the dial on one or several of them to correct >> for crystal aging. Then it was just more arithmetic again. Several of the >> oscillators had such low drift rates that all I needed was one daily phase >> reading from the VLF phase tracking receiver (Tracor 599Js) at those sites >> to know the frequency of the Sulzers there. >> >> ... Martin VE3OAT >> >> On Thu, 30 Aug 2018 12:27:12 -0400 >> Bob kb8tq wrote: >> >>> WWVB as transmitted ( = right at the input to the antenna) is a wonderfully >>> stable signal. As soon as >>> that signal hits the real world things start to degrade. Propagation >>> between transmit and receive sites >>> is a big deal, even at 60 KHz. On top of that, there is a*lot* of manmade >>> noise at 60 KHz. The receive >>> signal to noise will never be as good as you might like it to be ?. >> >>> I don't know about WWVB, but for DCF77 it's known that sunrise/sunset >>> causes a phase shift of several 100?s at even moderate distances >>> (like ~500km). Unfortunately I don't have any measurements at hand. >>>Attila Kinali >> >> >> ___ >> 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. > ___ 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.
Re: [time-nuts] WWV and legal issues
Hi, It was very telling when I crashed a research group into the reality of phase/time transfer over fiber compared to frequency transfer. Armed with a whiteboard and pens, I derived the forumulas and showed how they worked and not worked. It's a completely different ball-game and their "known tricks" ain't doing nothing good as it comes to time. I had to figure much of this out myself as I did nation-wide system design to achieve the goal. It's a combination of many skills that goes into designing the full system from scratch and make it fit together. It's not hard stuff, it's just many details one needs to get right. Oh the fun. Cheers, Magnus On 08/31/2018 05:15 PM, Bob kb8tq wrote: > Hi > > That works fine if you are doing things manual to check a local standard. If > you are trying to > disipline a few thousand cell towers 24 hours a day … not so much. It also > works for > checking frequency. What modern systems need is time. That gets you into a > whole > world of resolving and identifying individual edges. The WWVB signal really > was never > set up for this. Loran-C is an example of a signal that was designed to > identify a specific > edge. > > Bob > >> On Aug 31, 2018, at 10:30 AM, Martin VE3OAT wrote: >> >> But the diurnal phase shifts at VLF are predictable and largely repeatable. >> Ignore the phase at night and use only the phase records during the day when >> an all-daylight propagation path exists. You might have to "correct" the >> absolute phase reading by some multiple of the RF period, but with a low >> rate of local standard oscillator drift, this is a simple matter of >> arithmetic. Back in the day, I managed Sulzer crystal oscillators at 5 field >> sites from my office and could maintain phase continuity for weeks at a >> time, until we had to diddle the dial on one or several of them to correct >> for crystal aging. Then it was just more arithmetic again. Several of the >> oscillators had such low drift rates that all I needed was one daily phase >> reading from the VLF phase tracking receiver (Tracor 599Js) at those sites >> to know the frequency of the Sulzers there. >> >> ... Martin VE3OAT >> >> On Thu, 30 Aug 2018 12:27:12 -0400 >> Bob kb8tq wrote: >> >>> WWVB as transmitted ( = right at the input to the antenna) is a wonderfully >>> stable signal. As soon as >>> that signal hits the real world things start to degrade. Propagation >>> between transmit and receive sites >>> is a big deal, even at 60 KHz. On top of that, there is a*lot* of manmade >>> noise at 60 KHz. The receive >>> signal to noise will never be as good as you might like it to be ?. >> >>> I don't know about WWVB, but for DCF77 it's known that sunrise/sunset >>> causes a phase shift of several 100?s at even moderate distances >>> (like ~500km). Unfortunately I don't have any measurements at hand. >>> Attila Kinali >> >> >> ___ >> 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. > ___ 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.
Re: [time-nuts] WWV and legal issues
Hi Well if you have a magic piece of code that will do the trick, why don’t you share it with the rest of us? In …. errr …. 50+ years of looking at the problem, nobody else seems to have come up with an answer. It’s not because people have not tried. They’ve been working on this sort of thing since at least the 60’s. It was at the heart of some really big problems the DOD had with HF and VLF links. They poured some massive chunks of money into it. Bob > On Aug 31, 2018, at 12:30 PM, Scott McGrath wrote: > > Strangely enough there are these devices called ‘computers’ which are rumored > to be able to perform measurements and mathematical calculations. > > One of these ‘computers’ might be profitably employed to perform the > necessary measurements calculations and deliver a useful output, > > Employing a Mentat would be expensive for this task... > > > On Aug 31, 2018, at 11:37 AM, Tom Holmes wrote: > > Uh, folks...Would the apparently still on hiatus TVB approve of this on-going > Urinary Olympiad? Just asking. And hoping post this won’t start another one. > > Tom Holmes, N8ZM > > -Original Message- > From: time-nuts On Behalf Of Bob kb8tq > Sent: Friday, August 31, 2018 11:16 AM > To: Martin VE3OAT ; Discussion of precise time and frequency > measurement > Subject: Re: [time-nuts] WWV and legal issues > > Hi > > That works fine if you are doing things manual to check a local standard. If > you are trying to > disipline a few thousand cell towers 24 hours a day … not so much. It also > works for > checking frequency. What modern systems need is time. That gets you into a > whole > world of resolving and identifying individual edges. The WWVB signal really > was never > set up for this. Loran-C is an example of a signal that was designed to > identify a specific > edge. > > Bob > >> On Aug 31, 2018, at 10:30 AM, Martin VE3OAT wrote: >> >> But the diurnal phase shifts at VLF are predictable and largely repeatable. >> Ignore the phase at night and use only the phase records during the day when >> an all-daylight propagation path exists. You might have to "correct" the >> absolute phase reading by some multiple of the RF period, but with a low >> rate of local standard oscillator drift, this is a simple matter of >> arithmetic. Back in the day, I managed Sulzer crystal oscillators at 5 field >> sites from my office and could maintain phase continuity for weeks at a >> time, until we had to diddle the dial on one or several of them to correct >> for crystal aging. Then it was just more arithmetic again. Several of the >> oscillators had such low drift rates that all I needed was one daily phase >> reading from the VLF phase tracking receiver (Tracor 599Js) at those sites >> to know the frequency of the Sulzers there. >> >> ... Martin VE3OAT >> >> On Thu, 30 Aug 2018 12:27:12 -0400 >> Bob kb8tq wrote: >> >>> WWVB as transmitted ( = right at the input to the antenna) is a wonderfully >>> stable signal. As soon as >>> that signal hits the real world things start to degrade. Propagation >>> between transmit and receive sites >>> is a big deal, even at 60 KHz. On top of that, there is a*lot* of manmade >>> noise at 60 KHz. The receive >>> signal to noise will never be as good as you might like it to be ?. >> >>> I don't know about WWVB, but for DCF77 it's known that sunrise/sunset >>> causes a phase shift of several 100?s at even moderate distances >>> (like ~500km). Unfortunately I don't have any measurements at hand. >>> Attila Kinali >> >> >> ___ >> 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. > > > ___ > 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. ___ 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.
Re: [time-nuts] WWV and legal issues
Strangely enough there are these devices called ‘computers’ which are rumored to be able to perform measurements and mathematical calculations. One of these ‘computers’ might be profitably employed to perform the necessary measurements calculations and deliver a useful output, Employing a Mentat would be expensive for this task... On Aug 31, 2018, at 11:37 AM, Tom Holmes wrote: Uh, folks...Would the apparently still on hiatus TVB approve of this on-going Urinary Olympiad? Just asking. And hoping post this won’t start another one. Tom Holmes, N8ZM -Original Message- From: time-nuts On Behalf Of Bob kb8tq Sent: Friday, August 31, 2018 11:16 AM To: Martin VE3OAT ; Discussion of precise time and frequency measurement Subject: Re: [time-nuts] WWV and legal issues Hi That works fine if you are doing things manual to check a local standard. If you are trying to disipline a few thousand cell towers 24 hours a day … not so much. It also works for checking frequency. What modern systems need is time. That gets you into a whole world of resolving and identifying individual edges. The WWVB signal really was never set up for this. Loran-C is an example of a signal that was designed to identify a specific edge. Bob > On Aug 31, 2018, at 10:30 AM, Martin VE3OAT wrote: > > But the diurnal phase shifts at VLF are predictable and largely repeatable. > Ignore the phase at night and use only the phase records during the day when > an all-daylight propagation path exists. You might have to "correct" the > absolute phase reading by some multiple of the RF period, but with a low rate > of local standard oscillator drift, this is a simple matter of arithmetic. > Back in the day, I managed Sulzer crystal oscillators at 5 field sites from > my office and could maintain phase continuity for weeks at a time, until we > had to diddle the dial on one or several of them to correct for crystal > aging. Then it was just more arithmetic again. Several of the oscillators > had such low drift rates that all I needed was one daily phase reading from > the VLF phase tracking receiver (Tracor 599Js) at those sites to know the > frequency of the Sulzers there. > > ... Martin VE3OAT > > On Thu, 30 Aug 2018 12:27:12 -0400 > Bob kb8tq wrote: > >> WWVB as transmitted ( = right at the input to the antenna) is a wonderfully >> stable signal. As soon as >> that signal hits the real world things start to degrade. Propagation between >> transmit and receive sites >> is a big deal, even at 60 KHz. On top of that, there is a*lot* of manmade >> noise at 60 KHz. The receive >> signal to noise will never be as good as you might like it to be ?. > >> I don't know about WWVB, but for DCF77 it's known that sunrise/sunset >> causes a phase shift of several 100?s at even moderate distances >> (like ~500km). Unfortunately I don't have any measurements at hand. >>Attila Kinali > > > ___ > 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. ___ 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.
Re: [time-nuts] WWV and legal issues
Uh, folks...Would the apparently still on hiatus TVB approve of this on-going Urinary Olympiad? Just asking. And hoping post this won’t start another one. Tom Holmes, N8ZM -Original Message- From: time-nuts On Behalf Of Bob kb8tq Sent: Friday, August 31, 2018 11:16 AM To: Martin VE3OAT ; Discussion of precise time and frequency measurement Subject: Re: [time-nuts] WWV and legal issues Hi That works fine if you are doing things manual to check a local standard. If you are trying to disipline a few thousand cell towers 24 hours a day … not so much. It also works for checking frequency. What modern systems need is time. That gets you into a whole world of resolving and identifying individual edges. The WWVB signal really was never set up for this. Loran-C is an example of a signal that was designed to identify a specific edge. Bob > On Aug 31, 2018, at 10:30 AM, Martin VE3OAT wrote: > > But the diurnal phase shifts at VLF are predictable and largely repeatable. > Ignore the phase at night and use only the phase records during the day when > an all-daylight propagation path exists. You might have to "correct" the > absolute phase reading by some multiple of the RF period, but with a low rate > of local standard oscillator drift, this is a simple matter of arithmetic. > Back in the day, I managed Sulzer crystal oscillators at 5 field sites from > my office and could maintain phase continuity for weeks at a time, until we > had to diddle the dial on one or several of them to correct for crystal > aging. Then it was just more arithmetic again. Several of the oscillators > had such low drift rates that all I needed was one daily phase reading from > the VLF phase tracking receiver (Tracor 599Js) at those sites to know the > frequency of the Sulzers there. > > ... Martin VE3OAT > > On Thu, 30 Aug 2018 12:27:12 -0400 > Bob kb8tq wrote: > >> WWVB as transmitted ( = right at the input to the antenna) is a wonderfully >> stable signal. As soon as >> that signal hits the real world things start to degrade. Propagation between >> transmit and receive sites >> is a big deal, even at 60 KHz. On top of that, there is a*lot* of manmade >> noise at 60 KHz. The receive >> signal to noise will never be as good as you might like it to be ?. > > > I don't know about WWVB, but for DCF77 it's known that sunrise/sunset >> causes a phase shift of several 100?s at even moderate distances >> (like ~500km). Unfortunately I don't have any measurements at hand. >> Attila Kinali > > > ___ > 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. ___ 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.
Re: [time-nuts] WWV and legal issues
Hi That works fine if you are doing things manual to check a local standard. If you are trying to disipline a few thousand cell towers 24 hours a day … not so much. It also works for checking frequency. What modern systems need is time. That gets you into a whole world of resolving and identifying individual edges. The WWVB signal really was never set up for this. Loran-C is an example of a signal that was designed to identify a specific edge. Bob > On Aug 31, 2018, at 10:30 AM, Martin VE3OAT wrote: > > But the diurnal phase shifts at VLF are predictable and largely repeatable. > Ignore the phase at night and use only the phase records during the day when > an all-daylight propagation path exists. You might have to "correct" the > absolute phase reading by some multiple of the RF period, but with a low rate > of local standard oscillator drift, this is a simple matter of arithmetic. > Back in the day, I managed Sulzer crystal oscillators at 5 field sites from > my office and could maintain phase continuity for weeks at a time, until we > had to diddle the dial on one or several of them to correct for crystal > aging. Then it was just more arithmetic again. Several of the oscillators > had such low drift rates that all I needed was one daily phase reading from > the VLF phase tracking receiver (Tracor 599Js) at those sites to know the > frequency of the Sulzers there. > > ... Martin VE3OAT > > On Thu, 30 Aug 2018 12:27:12 -0400 > Bob kb8tq wrote: > >> WWVB as transmitted ( = right at the input to the antenna) is a wonderfully >> stable signal. As soon as >> that signal hits the real world things start to degrade. Propagation between >> transmit and receive sites >> is a big deal, even at 60 KHz. On top of that, there is a*lot* of manmade >> noise at 60 KHz. The receive >> signal to noise will never be as good as you might like it to be ?. > > > I don't know about WWVB, but for DCF77 it's known that sunrise/sunset >> causes a phase shift of several 100?s at even moderate distances >> (like ~500km). Unfortunately I don't have any measurements at hand. >> Attila Kinali > > > ___ > 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.
Re: [time-nuts] WWV and legal issues
Hi Same basic problem with WWVB. If you were using it as a reference, you timed your data collection to avoid the transition periods. You got both phase shifting and the amplitude took a dive. Neither one was going to help you make a precision measurement. In addition there are various weather events (terrestrial and solar) that can get into the mix. You can see blips here and there that do not correlate with the sunrise / sunset stuff. Again, not a big deal if you are manual evaluating the data to check your local Rb standard or super duper OCXO. Not a good thing for disciplining a system 24 hours a day 365 days a year. Bob > On Aug 30, 2018, at 1:54 PM, Attila Kinali wrote: > > On Thu, 30 Aug 2018 12:27:12 -0400 > Bob kb8tq wrote: > >> WWVB as transmitted ( = right at the input to the antenna) is a wonderfully >> stable signal. As soon as >> that signal hits the real world things start to degrade. Propagation between >> transmit and receive sites >> is a big deal, even at 60 KHz. On top of that, there is a *lot* of manmade >> noise at 60 KHz. The receive >> signal to noise will never be as good as you might like it to be …. > > I don't know about WWVB, but for DCF77 it's known that sunrise/sunset > causes a phase shift of several 100µs at even moderate distances > (like ~500km). Unfortunately I don't have any measurements at hand. > > > Attila Kinali > > -- > It is upon moral qualities that a society is ultimately founded. All > the prosperity and technological sophistication in the world is of no > use without that foundation. > -- Miss Matheson, The Diamond Age, Neal Stephenson > > ___ > 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.
Re: [time-nuts] WWV and legal issues
Hi With the Loran boxes, you were doing well to get down to the 100 ns level. When you did, it always was a questionable sort of reading. More or less - is this real??? I spent a *lot* of time watching that data …. Estimating what WWVB is doing over long baselines as the weather changes is not at all easy. To keep things in sync you need solid data all the time. Guessing at your time source and then trying to discipline against it does not make for a rational disciplining system. Again … I spent a lot of years looking at those phase plots. Could you do pretty well for a few days with either one? Sure you could. For a system time source you are looking at 24 hours a day / 365 days a year sort of performance. We are going round and round talking about the sort of solar flares that haven’t happened in many decades (if ever …). The sort of stuff that disrupts WWVB or Loran (at the 10’s or 100’s of nanoseconds level) happens many times a year, even in a good year. Ramp up the sun spots and it can get really interesting. Is it better if I can toss rocks and hit the transmit antenna? Sure it is. Not everybody was / is within a hundred miles of a master for Loran-C or of Ft. Colins for WWVB. If you are going to use WWVB, it’s got to work in Miami, Florida and in Bangor, Maine. Working out carrier phase on WWVB as MSF comes in at equal strength in New England … yikes …. There are good sound reasons why the WWVB disciplined systems gear got dumped a long time ago and replaced with GPS. The GPS based gear performs better and is more reliable. Bob > On Aug 30, 2018, at 12:46 PM, Scott McGrath wrote: > > One does not get the same instantaneous accuracy that one gets from GPS but > with a long baseline the offsets to your site can be determined.With > eLoran you can get similar levels of accuracy as the old Austron monitors > used to prove > > Content by Scott > Typos by Siri > > On Aug 30, 2018, at 12:27 PM, Bob kb8tq wrote: > > Hi > > WWVB as transmitted ( = right at the input to the antenna) is a wonderfully > stable signal. As soon as > that signal hits the real world things start to degrade. Propagation between > transmit and receive sites > is a big deal, even at 60 KHz. On top of that, there is a *lot* of manmade > noise at 60 KHz. The receive > signal to noise will never be as good as you might like it to be …. > > 60 KHz has a period of 16.667 us. GPS gives you ~10 ns sort of time quite > quickly. Resolving the WWVB > carrier to that level is a major challenge. Identifying a single “cycle edge” > as the magic timing ID with either > the old or new modulation formats …. yet another significant challenge. Net > result is that you just can’t > get the same sort of timing out of WWVB. > > Bob > >> On Aug 30, 2018, at 11:15 AM, Mike Bafaro wrote: >> >> According to what I have heard the 60KHz WWVB carrier is guaranteed accurate >> to the atomic standard and is considered traceable. I remember when I was >> in the Navy years ago I remember taking our unit's HP5245L for calibration >> and they used a VLF tracking receiver at 60KHz to do the calibration. If >> WWVB goes off the air what is the replacement for the 60KHz standard? >> >> Mike >> >> -Original Message- >> From: time-nuts [mailto:time-nuts-boun...@lists.febo.com] On Behalf Of Perry >> Sandeen via time-nuts >> Sent: Wednesday, August 29, 2018 6:34 PM >> To: time-nuts@lists.febo.com >> Cc: Perry Sandeen >> Subject: [time-nuts] WWV and legal issues >> >> Yo Dudes!� >> WWV and all its variations distribute what in the USA is the legal standard >> of time (from USNO) and frequency (NIST). >> �If one is running a freq cal service IIRC it is a legal requirement to be >> able to have traceability to WWV. >> >> If one was to rely on other sources, one has no guarantee that it 1. It is >> as accurate as claimed and 2. It can't be *diddled* with accidentally or >> deliberately. >> Although GPSDO's are very good and popular, they come from satellites that >> are vulnerable to damage from earth based resources. >> When your time and frequency standard(s) is under control on your own >> physical territory then they stand or fail on their own.� >> After the atom bombing of Hiroshima and Nagasaki, one of the major inventors >> of the bomb (I don't remember who) went to see US president Harry Truman and >> essentially told him that the scientists who developed the bomb should have >> a say of how or when it should be used. >> Truman is reported to have said for him to leave his office and told an aid >> that was responsible for his schedule to "never in hell let that (or
Re: [time-nuts] WWV and legal issues
One does not get the same instantaneous accuracy that one gets from GPS but with a long baseline the offsets to your site can be determined.With eLoran you can get similar levels of accuracy as the old Austron monitors used to prove Content by Scott Typos by Siri On Aug 30, 2018, at 12:27 PM, Bob kb8tq wrote: Hi WWVB as transmitted ( = right at the input to the antenna) is a wonderfully stable signal. As soon as that signal hits the real world things start to degrade. Propagation between transmit and receive sites is a big deal, even at 60 KHz. On top of that, there is a *lot* of manmade noise at 60 KHz. The receive signal to noise will never be as good as you might like it to be …. 60 KHz has a period of 16.667 us. GPS gives you ~10 ns sort of time quite quickly. Resolving the WWVB carrier to that level is a major challenge. Identifying a single “cycle edge” as the magic timing ID with either the old or new modulation formats …. yet another significant challenge. Net result is that you just can’t get the same sort of timing out of WWVB. Bob > On Aug 30, 2018, at 11:15 AM, Mike Bafaro wrote: > > According to what I have heard the 60KHz WWVB carrier is guaranteed accurate > to the atomic standard and is considered traceable. I remember when I was in > the Navy years ago I remember taking our unit's HP5245L for calibration and > they used a VLF tracking receiver at 60KHz to do the calibration. If WWVB > goes off the air what is the replacement for the 60KHz standard? > > Mike > > -Original Message- > From: time-nuts [mailto:time-nuts-boun...@lists.febo.com] On Behalf Of Perry > Sandeen via time-nuts > Sent: Wednesday, August 29, 2018 6:34 PM > To: time-nuts@lists.febo.com > Cc: Perry Sandeen > Subject: [time-nuts] WWV and legal issues > > Yo Dudes!� > WWV and all its variations distribute what in the USA is the legal standard > of time (from USNO) and frequency (NIST). > �If one is running a freq cal service IIRC it is a legal requirement to be > able to have traceability to WWV. > > If one was to rely on other sources, one has no guarantee that it 1. It is as > accurate as claimed and 2. It can't be *diddled* with accidentally or > deliberately. > Although GPSDO's are very good and popular, they come from satellites that > are vulnerable to damage from earth based resources. > When your time and frequency standard(s) is under control on your own > physical territory then they stand or fail on their own.� > After the atom bombing of Hiroshima and Nagasaki, one of the major inventors > of the bomb (I don't remember who) went to see US president Harry Truman and > essentially told him that the scientists who developed the bomb should have a > say of how or when it should be used. > Truman is reported to have said for him to leave his office and told an aid > that was responsible for his schedule to "never in hell let that (or any > other) scientist� come to his office to influence American defense policy." > Considering its status from both a scientific and political perspective, > IMNSHO it will go on as before. > To explain the political. No government official wants to see China or the > Russian federation tell the world quote: See, the USA can't be trusted for > something as important and simple as frequency and time.� However we are your > friends who you can trust. Unquote. > Regards, > > > > > > This is a case of practical use of WWV albeit over 50 years a go the > fundamentals are still valid today. > At Karamursel Air station TUSLOG 234 I was assigned to the base receiver > site.� Our base had to purposes.� to� � > > > > > ___ > 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. ___ 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.
Re: [time-nuts] WWV and legal issues
Hi WWVB as transmitted ( = right at the input to the antenna) is a wonderfully stable signal. As soon as that signal hits the real world things start to degrade. Propagation between transmit and receive sites is a big deal, even at 60 KHz. On top of that, there is a *lot* of manmade noise at 60 KHz. The receive signal to noise will never be as good as you might like it to be …. 60 KHz has a period of 16.667 us. GPS gives you ~10 ns sort of time quite quickly. Resolving the WWVB carrier to that level is a major challenge. Identifying a single “cycle edge” as the magic timing ID with either the old or new modulation formats …. yet another significant challenge. Net result is that you just can’t get the same sort of timing out of WWVB. Bob > On Aug 30, 2018, at 11:15 AM, Mike Bafaro wrote: > > According to what I have heard the 60KHz WWVB carrier is guaranteed accurate > to the atomic standard and is considered traceable. I remember when I was in > the Navy years ago I remember taking our unit's HP5245L for calibration and > they used a VLF tracking receiver at 60KHz to do the calibration. If WWVB > goes off the air what is the replacement for the 60KHz standard? > > Mike > > -Original Message- > From: time-nuts [mailto:time-nuts-boun...@lists.febo.com] On Behalf Of Perry > Sandeen via time-nuts > Sent: Wednesday, August 29, 2018 6:34 PM > To: time-nuts@lists.febo.com > Cc: Perry Sandeen > Subject: [time-nuts] WWV and legal issues > > Yo Dudes!� > WWV and all its variations distribute what in the USA is the legal standard > of time (from USNO) and frequency (NIST). > �If one is running a freq cal service IIRC it is a legal requirement to be > able to have traceability to WWV. > > If one was to rely on other sources, one has no guarantee that it 1. It is as > accurate as claimed and 2. It can't be *diddled* with accidentally or > deliberately. > Although GPSDO's are very good and popular, they come from satellites that > are vulnerable to damage from earth based resources. > When your time and frequency standard(s) is under control on your own > physical territory then they stand or fail on their own.� > After the atom bombing of Hiroshima and Nagasaki, one of the major inventors > of the bomb (I don't remember who) went to see US president Harry Truman and > essentially told him that the scientists who developed the bomb should have a > say of how or when it should be used. > Truman is reported to have said for him to leave his office and told an aid > that was responsible for his schedule to "never in hell let that (or any > other) scientist� come to his office to influence American defense policy." > Considering its status from both a scientific and political perspective, > IMNSHO it will go on as before. > To explain the political. No government official wants to see China or the > Russian federation tell the world quote: See, the USA can't be trusted for > something as important and simple as frequency and time.� However we are your > friends who you can trust. Unquote. > Regards, > > > > > > This is a case of practical use of WWV albeit over 50 years a go the > fundamentals are still valid today. > At Karamursel Air station TUSLOG 234 I was assigned to the base receiver > site.� Our base had to purposes.� to� � > > > > > ___ > 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. ___ 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.
Re: [time-nuts] WWV and legal issues
Management signed a PO for the previously "unneeded" Symmetricom units that had been requested a year earlier the next day... Jim From: time-nuts on behalf of Scott McGrath Sent: Thursday, August 30, 2018 11:24:03 AM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] WWV and legal issues Bingo - we have a a Winner!!! In a prior life as an architect at a northeastern we had Cs clocks, multiple GPS based NTP servers and CDMA NTP servers as TIME was the public key for all the crypto systems the Cs clocks were there in case GPS ‘went away’ for any reason and with service reliability as the primary goal instead of ‘maximizing shareholder value’ we made sure that precision timing could survive anything short of total destruction of the campus and our backup sites. On Aug 30, 2018, at 11:04 AM, James C Cotton wrote: Time is the public key for a lot of the crypto that runs on networks. Any large university or corporation has multiple GPS based time sources and compares them to others... Back in the mid-1980's a fire in a CO in East Lansing, MI and a backhoe in Jackson, MI took out the Internet connections at the university I work at. A couple of routers using time as the public key and exchanging encrypted routing packets were isolated. Jim Cotton From: time-nuts on behalf of Scott McGrath Sent: Thursday, August 30, 2018 10:42:45 AM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] WWV and legal issues Um no Will the internet continue to route packets without precision timing yes it will, Yes the lambdas will stay lit on fiber but the ATM transport that runs on the lambdas will fail (note DSL is simply an ATM VC over copper). and other timing dependent services will fail Will many services like authentication continue especially those based on multimaster replication continue to function? No they will not, they are totally dependent on precision timing to ensure proper replication sourcing. (Microsoft Active Directory) Banking transactions in the same boat. Unless you’ve actually run a large network you dont realize just how dependent on precision timing the services running over the network have become especially authentication And one reason for this is increased security for the overall network. On Aug 30, 2018, at 8:45 AM, Brian Lloyd wrote: On Thu, Aug 30, 2018 at 7:01 AM, Scott McGrath wrote: > > > > Without precision timing there is no telephone network, cell phones or > internet. And that only became true in the last 20 years or so as long > haul networks went from FDM on coaxial cable to TDM on fibre. > The Internet is largely asynchronous due to the store-and-forward nature of the routers. Fiber capacity is increased through the use of wavelength division multiplexing (WDM) which is itself a form of FDM. The Internet functions without any sort of central synchronization. Yes, there are portions that run over the synchronized telco services but that is by convenience, not necessity. -- Brian Lloyd 706 Flightline Spring Branch, TX 78070 br...@lloyd.aero +1.210.802-8FLY (1.210.802-8359) ___ 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. ___ 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. ___ 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.
Re: [time-nuts] WWV and legal issues
Bingo - we have a a Winner!!! In a prior life as an architect at a northeastern we had Cs clocks, multiple GPS based NTP servers and CDMA NTP servers as TIME was the public key for all the crypto systems the Cs clocks were there in case GPS ‘went away’ for any reason and with service reliability as the primary goal instead of ‘maximizing shareholder value’ we made sure that precision timing could survive anything short of total destruction of the campus and our backup sites. On Aug 30, 2018, at 11:04 AM, James C Cotton wrote: Time is the public key for a lot of the crypto that runs on networks. Any large university or corporation has multiple GPS based time sources and compares them to others... Back in the mid-1980's a fire in a CO in East Lansing, MI and a backhoe in Jackson, MI took out the Internet connections at the university I work at. A couple of routers using time as the public key and exchanging encrypted routing packets were isolated. Jim Cotton From: time-nuts on behalf of Scott McGrath Sent: Thursday, August 30, 2018 10:42:45 AM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] WWV and legal issues Um no Will the internet continue to route packets without precision timing yes it will, Yes the lambdas will stay lit on fiber but the ATM transport that runs on the lambdas will fail (note DSL is simply an ATM VC over copper). and other timing dependent services will fail Will many services like authentication continue especially those based on multimaster replication continue to function? No they will not, they are totally dependent on precision timing to ensure proper replication sourcing. (Microsoft Active Directory) Banking transactions in the same boat. Unless you’ve actually run a large network you dont realize just how dependent on precision timing the services running over the network have become especially authentication And one reason for this is increased security for the overall network. On Aug 30, 2018, at 8:45 AM, Brian Lloyd wrote: On Thu, Aug 30, 2018 at 7:01 AM, Scott McGrath wrote: > > > > Without precision timing there is no telephone network, cell phones or > internet. And that only became true in the last 20 years or so as long > haul networks went from FDM on coaxial cable to TDM on fibre. > The Internet is largely asynchronous due to the store-and-forward nature of the routers. Fiber capacity is increased through the use of wavelength division multiplexing (WDM) which is itself a form of FDM. The Internet functions without any sort of central synchronization. Yes, there are portions that run over the synchronized telco services but that is by convenience, not necessity. -- Brian Lloyd 706 Flightline Spring Branch, TX 78070 br...@lloyd.aero +1.210.802-8FLY (1.210.802-8359) ___ 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. ___ 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.
Re: [time-nuts] WWV and legal issues
Hi This is not so much a GPS issue as a system design issue. GPSDO’s are used to “smooth over” bumps in a lot of systems out there. At the timing levels required by ATM or authentication setups, you can go a *long* time running on a GPSDO. It’s not a matter of GPS, it’s a matter of doing things on the cheap …. Bob > On Aug 30, 2018, at 10:42 AM, Scott McGrath wrote: > > Um no > > Will the internet continue to route packets without precision timing yes it > will, Yes the lambdas will stay lit on fiber but the ATM transport that runs > on the lambdas will fail (note DSL is simply an ATM VC over copper). and > other timing dependent services will fail > > Will many services like authentication continue especially those based on > multimaster replication continue to function? > > No they will not, they are totally dependent on precision timing to ensure > proper replication sourcing. (Microsoft Active Directory) > > Banking transactions in the same boat. > > Unless you’ve actually run a large network you dont realize just how > dependent on precision timing the services running over the network have > become especially authentication And one reason for this is increased > security for the overall network. > > On Aug 30, 2018, at 8:45 AM, Brian Lloyd wrote: > > On Thu, Aug 30, 2018 at 7:01 AM, Scott McGrath wrote: > >> >> >> >> Without precision timing there is no telephone network, cell phones or >> internet. And that only became true in the last 20 years or so as long >> haul networks went from FDM on coaxial cable to TDM on fibre. >> > > The Internet is largely asynchronous due to the store-and-forward nature of > the routers. Fiber capacity is increased through the use of wavelength > division multiplexing (WDM) which is itself a form of FDM. The Internet > functions without any sort of central synchronization. > > Yes, there are portions that run over the synchronized telco services but > that is by convenience, not necessity. > > -- > > > > Brian Lloyd > 706 Flightline > Spring Branch, TX 78070 > br...@lloyd.aero > +1.210.802-8FLY (1.210.802-8359) > ___ > 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. ___ 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.
Re: [time-nuts] WWV and legal issues
Time is the public key for a lot of the crypto that runs on networks. Any large university or corporation has multiple GPS based time sources and compares them to others... Back in the mid-1980's a fire in a CO in East Lansing, MI and a backhoe in Jackson, MI took out the Internet connections at the university I work at. A couple of routers using time as the public key and exchanging encrypted routing packets were isolated. Jim Cotton From: time-nuts on behalf of Scott McGrath Sent: Thursday, August 30, 2018 10:42:45 AM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] WWV and legal issues Um no Will the internet continue to route packets without precision timing yes it will, Yes the lambdas will stay lit on fiber but the ATM transport that runs on the lambdas will fail (note DSL is simply an ATM VC over copper). and other timing dependent services will fail Will many services like authentication continue especially those based on multimaster replication continue to function? No they will not, they are totally dependent on precision timing to ensure proper replication sourcing. (Microsoft Active Directory) Banking transactions in the same boat. Unless you’ve actually run a large network you dont realize just how dependent on precision timing the services running over the network have become especially authentication And one reason for this is increased security for the overall network. On Aug 30, 2018, at 8:45 AM, Brian Lloyd wrote: On Thu, Aug 30, 2018 at 7:01 AM, Scott McGrath wrote: > > > > Without precision timing there is no telephone network, cell phones or > internet. And that only became true in the last 20 years or so as long > haul networks went from FDM on coaxial cable to TDM on fibre. > The Internet is largely asynchronous due to the store-and-forward nature of the routers. Fiber capacity is increased through the use of wavelength division multiplexing (WDM) which is itself a form of FDM. The Internet functions without any sort of central synchronization. Yes, there are portions that run over the synchronized telco services but that is by convenience, not necessity. -- Brian Lloyd 706 Flightline Spring Branch, TX 78070 br...@lloyd.aero +1.210.802-8FLY (1.210.802-8359) ___ 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. ___ 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.
Re: [time-nuts] WWV and legal issues
On Thu, Aug 30, 2018 at 9:42 AM, Scott McGrath wrote: > Um no > > Will the internet continue to route packets without precision timing yes > it will, Yes the lambdas will stay lit on fiber but the ATM transport that > runs on the lambdas will fail (note DSL is simply an ATM VC over copper). > and other timing dependent services will fail > You may find less ATM on the fast links than you think. > > Will many services like authentication continue especially those based on > multimaster replication continue to function? > > No they will not, they are totally dependent on precision timing to > ensure proper replication sourcing. (Microsoft Active Directory) Precision timing better than NTP? Are you sure? I guess there are some using Microsoft stuff but the fabric of the Internet sure doesn't depend on it. > > Banking transactions in the same boat. > Same question. > > Unless you’ve actually run a large network you dont realize just how > dependent on precision timing the services running over the network have > become especially authentication And one reason for this is increased > security for the overall network. > Yeah, I have some experience with running a large net. I have a little experience with how the Internet runs. ;-) -- Brian Lloyd 706 Flightline Spring Branch, TX 78070 br...@lloyd.aero +1.210.802-8FLY (1.210.802-8359) ___ 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.
Re: [time-nuts] WWV and legal issues
Um no Will the internet continue to route packets without precision timing yes it will, Yes the lambdas will stay lit on fiber but the ATM transport that runs on the lambdas will fail (note DSL is simply an ATM VC over copper). and other timing dependent services will fail Will many services like authentication continue especially those based on multimaster replication continue to function? No they will not, they are totally dependent on precision timing to ensure proper replication sourcing. (Microsoft Active Directory) Banking transactions in the same boat. Unless you’ve actually run a large network you dont realize just how dependent on precision timing the services running over the network have become especially authentication And one reason for this is increased security for the overall network. On Aug 30, 2018, at 8:45 AM, Brian Lloyd wrote: On Thu, Aug 30, 2018 at 7:01 AM, Scott McGrath wrote: > > > > Without precision timing there is no telephone network, cell phones or > internet. And that only became true in the last 20 years or so as long > haul networks went from FDM on coaxial cable to TDM on fibre. > The Internet is largely asynchronous due to the store-and-forward nature of the routers. Fiber capacity is increased through the use of wavelength division multiplexing (WDM) which is itself a form of FDM. The Internet functions without any sort of central synchronization. Yes, there are portions that run over the synchronized telco services but that is by convenience, not necessity. -- Brian Lloyd 706 Flightline Spring Branch, TX 78070 br...@lloyd.aero +1.210.802-8FLY (1.210.802-8359) ___ 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.
Re: [time-nuts] WWV and legal issues
Hi One of the basic disconnects here seems to be the idea that radio was the “best thing” before GPS came along. In fact that’s not really how it worked. Time was traced / coordinated by hauling atomic clocks on airplanes as the “best thing” before satellite systems came along….That was true for decades... Bob > On Aug 29, 2018, at 7:54 PM, Scott McGrath wrote: > > A DIY radio distribution system is not secure and traceable to NIST/USNO even > if the source is GPS. > > > > On Aug 29, 2018, at 7:52 PM, Scott McGrath wrote: > > Excellent point on LEGAL time, The problem is as always is GPS is the new > shiny object. > > You mentioned earth based hostile actors. But a really large solar flare or > CME has the potential to take out or severely degrade ALL the GNSS systems. > > Something on the order of the ‘Carrington Event’ or the flare in 1989 which > took out power to much of Canada. > > Things like this are why we need terrestrial time distribution systems like > eLORAN which by its nature is resistant to both man made and natural > interference. > > On Aug 29, 2018, at 7:33 PM, Perry Sandeen via time-nuts > wrote: > > Yo Dudes! > WWV and all its variations distribute what in the USA is the legal standard > of time (from USNO) and frequency (NIST). > If one is running a freq cal service IIRC it is a legal requirement to be > able to have traceability to WWV. > > If one was to rely on other sources, one has no guarantee that it 1. It is as > accurate as claimed and 2. It can't be *diddled* with accidentally or > deliberately. > Although GPSDO's are very good and popular, they come from satellites that > are vulnerable to damage from earth based resources. > When your time and frequency standard(s) is under control on your own > physical territory then they stand or fail on their own. > After the atom bombing of Hiroshima and Nagasaki, one of the major inventors > of the bomb (I don't remember who) went to see US president Harry Truman and > essentially told him that the scientists who developed the bomb should have a > say of how or when it should be used. > Truman is reported to have said for him to leave his office and told an aid > that was responsible for his schedule to "never in hell let that (or any > other) scientist come to his office to influence American defense policy." > Considering its status from both a scientific and political perspective, > IMNSHO it will go on as before. > To explain the political. No government official wants to see China or the > Russian federation tell the world quote: See, the USA can't be trusted for > something as important and simple as frequency and time. However we are your > friends who you can trust. Unquote. > Regards, > > > > > > This is a case of practical use of WWV albeit over 50 years a go the > fundamentals are still valid today. > At Karamursel Air station TUSLOG 234 I was assigned to the base receiver > site. Our base had to purposes. to > > > > > ___ > 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. ___ 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.
Re: [time-nuts] WWV and legal issues
Hi The same sort of massive solar flare that fiddles with sat systems also makes a mess of HF and VLF systems. You have a high level of correlation in the impact. That makes them a poor “backup” in this case. Bob > On Aug 29, 2018, at 7:52 PM, Scott McGrath wrote: > > Excellent point on LEGAL time, The problem is as always is GPS is the new > shiny object. > > You mentioned earth based hostile actors. But a really large solar flare or > CME has the potential to take out or severely degrade ALL the GNSS systems. > > Something on the order of the ‘Carrington Event’ or the flare in 1989 which > took out power to much of Canada. > > Things like this are why we need terrestrial time distribution systems like > eLORAN which by its nature is resistant to both man made and natural > interference. > > On Aug 29, 2018, at 7:33 PM, Perry Sandeen via time-nuts > wrote: > > Yo Dudes! > WWV and all its variations distribute what in the USA is the legal standard > of time (from USNO) and frequency (NIST). > If one is running a freq cal service IIRC it is a legal requirement to be > able to have traceability to WWV. > > If one was to rely on other sources, one has no guarantee that it 1. It is as > accurate as claimed and 2. It can't be *diddled* with accidentally or > deliberately. > Although GPSDO's are very good and popular, they come from satellites that > are vulnerable to damage from earth based resources. > When your time and frequency standard(s) is under control on your own > physical territory then they stand or fail on their own. > After the atom bombing of Hiroshima and Nagasaki, one of the major inventors > of the bomb (I don't remember who) went to see US president Harry Truman and > essentially told him that the scientists who developed the bomb should have a > say of how or when it should be used. > Truman is reported to have said for him to leave his office and told an aid > that was responsible for his schedule to "never in hell let that (or any > other) scientist come to his office to influence American defense policy." > Considering its status from both a scientific and political perspective, > IMNSHO it will go on as before. > To explain the political. No government official wants to see China or the > Russian federation tell the world quote: See, the USA can't be trusted for > something as important and simple as frequency and time. However we are your > friends who you can trust. Unquote. > Regards, > > > > > > This is a case of practical use of WWV albeit over 50 years a go the > fundamentals are still valid today. > At Karamursel Air station TUSLOG 234 I was assigned to the base receiver > site. Our base had to purposes. to > > > > > ___ > 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. ___ 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.
Re: [time-nuts] WWV and legal issues
A DIY radio distribution system is not secure and traceable to NIST/USNO even if the source is GPS. On Aug 29, 2018, at 7:52 PM, Scott McGrath wrote: Excellent point on LEGAL time, The problem is as always is GPS is the new shiny object. You mentioned earth based hostile actors. But a really large solar flare or CME has the potential to take out or severely degrade ALL the GNSS systems. Something on the order of the ‘Carrington Event’ or the flare in 1989 which took out power to much of Canada. Things like this are why we need terrestrial time distribution systems like eLORAN which by its nature is resistant to both man made and natural interference. On Aug 29, 2018, at 7:33 PM, Perry Sandeen via time-nuts wrote: Yo Dudes! WWV and all its variations distribute what in the USA is the legal standard of time (from USNO) and frequency (NIST). If one is running a freq cal service IIRC it is a legal requirement to be able to have traceability to WWV. If one was to rely on other sources, one has no guarantee that it 1. It is as accurate as claimed and 2. It can't be *diddled* with accidentally or deliberately. Although GPSDO's are very good and popular, they come from satellites that are vulnerable to damage from earth based resources. When your time and frequency standard(s) is under control on your own physical territory then they stand or fail on their own. After the atom bombing of Hiroshima and Nagasaki, one of the major inventors of the bomb (I don't remember who) went to see US president Harry Truman and essentially told him that the scientists who developed the bomb should have a say of how or when it should be used. Truman is reported to have said for him to leave his office and told an aid that was responsible for his schedule to "never in hell let that (or any other) scientist come to his office to influence American defense policy." Considering its status from both a scientific and political perspective, IMNSHO it will go on as before. To explain the political. No government official wants to see China or the Russian federation tell the world quote: See, the USA can't be trusted for something as important and simple as frequency and time. However we are your friends who you can trust. Unquote. Regards, This is a case of practical use of WWV albeit over 50 years a go the fundamentals are still valid today. At Karamursel Air station TUSLOG 234 I was assigned to the base receiver site. Our base had to purposes. to ___ 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.
Re: [time-nuts] WWV and legal issues
Excellent point on LEGAL time, The problem is as always is GPS is the new shiny object. You mentioned earth based hostile actors. But a really large solar flare or CME has the potential to take out or severely degrade ALL the GNSS systems. Something on the order of the ‘Carrington Event’ or the flare in 1989 which took out power to much of Canada. Things like this are why we need terrestrial time distribution systems like eLORAN which by its nature is resistant to both man made and natural interference. On Aug 29, 2018, at 7:33 PM, Perry Sandeen via time-nuts wrote: Yo Dudes! WWV and all its variations distribute what in the USA is the legal standard of time (from USNO) and frequency (NIST). If one is running a freq cal service IIRC it is a legal requirement to be able to have traceability to WWV. If one was to rely on other sources, one has no guarantee that it 1. It is as accurate as claimed and 2. It can't be *diddled* with accidentally or deliberately. Although GPSDO's are very good and popular, they come from satellites that are vulnerable to damage from earth based resources. When your time and frequency standard(s) is under control on your own physical territory then they stand or fail on their own. After the atom bombing of Hiroshima and Nagasaki, one of the major inventors of the bomb (I don't remember who) went to see US president Harry Truman and essentially told him that the scientists who developed the bomb should have a say of how or when it should be used. Truman is reported to have said for him to leave his office and told an aid that was responsible for his schedule to "never in hell let that (or any other) scientist come to his office to influence American defense policy." Considering its status from both a scientific and political perspective, IMNSHO it will go on as before. To explain the political. No government official wants to see China or the Russian federation tell the world quote: See, the USA can't be trusted for something as important and simple as frequency and time. However we are your friends who you can trust. Unquote. Regards, This is a case of practical use of WWV albeit over 50 years a go the fundamentals are still valid today. At Karamursel Air station TUSLOG 234 I was assigned to the base receiver site. Our base had to purposes. to ___ 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.
[time-nuts] WWV and legal issues
Yo Dudes! WWV and all its variations distribute what in the USA is the legal standard of time (from USNO) and frequency (NIST). If one is running a freq cal service IIRC it is a legal requirement to be able to have traceability to WWV. If one was to rely on other sources, one has no guarantee that it 1. It is as accurate as claimed and 2. It can't be *diddled* with accidentally or deliberately. Although GPSDO's are very good and popular, they come from satellites that are vulnerable to damage from earth based resources. When your time and frequency standard(s) is under control on your own physical territory then they stand or fail on their own. After the atom bombing of Hiroshima and Nagasaki, one of the major inventors of the bomb (I don't remember who) went to see US president Harry Truman and essentially told him that the scientists who developed the bomb should have a say of how or when it should be used. Truman is reported to have said for him to leave his office and told an aid that was responsible for his schedule to "never in hell let that (or any other) scientist come to his office to influence American defense policy." Considering its status from both a scientific and political perspective, IMNSHO it will go on as before. To explain the political. No government official wants to see China or the Russian federation tell the world quote: See, the USA can't be trusted for something as important and simple as frequency and time. However we are your friends who you can trust. Unquote. Regards, This is a case of practical use of WWV albeit over 50 years a go the fundamentals are still valid today. At Karamursel Air station TUSLOG 234 I was assigned to the base receiver site. Our base had to purposes. to ___ 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.
