On Sunday, August 9, 2020, 9:21:23 PM EDT, Bob kb8tq <kb8tq@n1k.org> wrote:

Hi Kamiya san, I know there is only one company in Japan that uses STL service from Iridium (via Spectracom as Vendor). However I cant disclose the information more detail. Best Regards, Dikshie On Mon, Aug 10, 2020 at 12:23 PM Taka Kamiya via time-nuts <time-nuts@lists.febo.com> wrote: > > I've done some quick research. I do not see timing as one of the services provided. I wonder if it can be achieved by just listening into what's already transmitted (like GPS) and do some math on our side. > > On more broader sense, was GPS originally designed to provide timing service? Or is it a byproduct of needing to measure location and speed, thus it needed a constant signal, and that using it to sync reference signal is just an ancillary and after-thought use cases? > > --------------------------------------- > (Mr.) Taka Kamiya > KB4EMF / ex JF2DKG > > > On Sunday, August 9, 2020, 9:21:23 PM EDT, Bob kb8tq <kb8tq@n1k.org> wrote: > > Hi > > > > > On Aug 9, 2020, at 7:03 PM, Tom Van Baak <tvb@LeapSecond.com> wrote: > > > > Hi Stu, > > > > There's no problem with a semi-commercial posting here. You've been a member for a decade and frequent contributor plus the subject matter is exactly on-topic. So thanks for posting. > > > > I spent a while on your web site and didn't uncover a trove of white papers. If you could post some URL's that would be appreciated. You don't have to worry about being less accurate than GPS. I mean, there are often far more important factors than nanosecond precision. > > To that point ( as accurate as GPS ) ….. GPS is simply a convent comparison system. Saying that > this or that is better or worse at this or that tau is *not* the same as saying it has more or less value. > It’s simply a system that is out there to be compared to. > > Bob > > > > You didn't mention pricing; it's hard to imagine it's as free as GPS so that seems like another disadvantage to me. > > > > Your comment about fewer satellites is spot on. That will be taken care of if you give SpaceX / Starlink a call and join that bandwagon. There are already 597 Starlink [1] satellites up there vs. 82 Iridium [2] satellites, yes? > > > > If you have entry-level / hobbyist grade evaluation kits I'm sure a number of us would be very interested to try it out. > > > > Thanks, > > /tvb > > > > [1] https://en.wikipedia.org/wiki/Starlink > > > > [2] https://en.wikipedia.org/wiki/Iridium_satellite_constellation > > > > > > On 8/9/2020 2:53 PM, Stewart Cobb wrote: > >> Taka Kamiya and Forrest Christian both asked recently about the alternative > >> satellite PNT system using the Iridium satellites. That system was > >> developed by my company, Satelles. It has been commercially available for > >> more than a year now. > >> > >> The biggest advantage is that our signal is at least 30 dB stronger than > >> GNSS signals (the exact numbers depend on whether you're talking to > >> engineering or marketing :). You can easily get a usable signal in deep > >> jungle, or a data center in the middle of a building's basement, or even > >> inside a locked shipping container. The stronger signal is correspondingly > >> more difficult to jam or spoof than GNSS, and our signal has anti-spoofing > >> features as well. > >> > >> The biggest disadvantage is that it is not quite as accurate as GPS, > >> because there are fewer satellites in view at any given time. > >> > >> I don't want to quote exact timing numbers here, because they depend a lot > >> on system integration details, but you can easily steer an OCXO within a > >> few hundred nanoseconds of USNO time. With a rubidium, you can do > >> considerably better. > >> > >> If you want to know more, our website is www.satellesinc.com. > >> > >> (If this message has been too commercial, I apologize in advance. The > >> boundary between information and salesmanship is not always sharp.) > >> > >> Cheers! > >> --Stu > >> _______________________________________________ > >> 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. -- -dikshie-

I did attend those conferences, it was my first ex poser to Dual Mixer, NIST presented it for high precision frequency measurements. Still have copies of the proceedings.Time is and was key but I do not recall any papers addressing using GPS for time distribution as we know it today, and that is what I was responding to the question that I answered to. Also writing the proposals and attending all project reviews it was never covered. Bert Kehren   In a message dated 8/10/2020 10:48:12 AM Eastern Standard Time, kb8tq@n1k.org writes:  Hi >From what I saw as the system was developed, the people doing it realized that timing was at the core of the design. If there was a timing problem, nothing was going to work. There were GPS (and before that other sat-nav) presentations at the Frequency Control Symposium for many years. The “big boys” in timing all were involved in GPS one way or the other. NIST was doing time transfer work on GPS before the system was fully up and running. Their results are (to a great degree) what got everybody believing  that GPS *could* be a good source of time. Those papers started early and kept on flowing …. Until they put their “stamp of approval” on the technique, I don’t think anybody was ready to call it a super time source. This is by no means to imply that NIST was the only outfit involved or that the others who also evaluated GPS somehow did not contribute. That’s far from the case. The only point is that NIST got out there early. Bob > On Aug 10, 2020, at 5:09 AM, ew via time-nuts <time-nuts@lists.febo.com> wrote: > > Attached are two pictures from my TI days as program Manager of the first GPS. There was no discussions of consumer use or timing application. Focus was on military application being able to guide a bomb in to a chimney. The cost per device was $ 300 000. Because of my high security clearance I was asked to brief the NSA and CIA on the future of GPS equipment. With my semiconductor background Moores Law and previously involved in consumer calculator development I predicted the size of a brick and $ 3000.  I was declared the company Idiot lost all credibility as a strategic thinker ans subsequently left TI. When Magellan came out with there handheld unit they remembered me and send me one. Still have it. When two years later the units the size of a cigarette pack came out and where given away if you took a Cadillac test drive the asked for it back. I refused. History.Bert Kehren    In a message dated 8/9/2020 11:23:33 PM Eastern Standard Time, time-nuts@lists.febo.com writes: > I've done some quick research.  I do not see timing as one of the services provided.  I wonder if it can be achieved by just listening into what's already transmitted (like GPS) and do some math on our side. > > On more broader sense, was GPS originally designed to provide timing service?  Or is it a byproduct of needing to measure location and speed, thus it needed a constant signal, and that using it to sync reference signal is just an ancillary and after-thought use cases? > > --------------------------------------- > (Mr.) Taka Kamiya > KB4EMF / ex JF2DKG > > >    On Sunday, August 9, 2020, 9:21:23 PM EDT, Bob kb8tq <kb8tq@n1k.org> wrote:  > > Hi > > > >> On Aug 9, 2020, at 7:03 PM, Tom Van Baak <tvb@LeapSecond.com> wrote: >> >> Hi Stu, >> >> There's no problem with a semi-commercial posting here. You've been a member for a decade and frequent contributor plus the subject matter is exactly on-topic. So thanks for posting. >> >> I spent a while on your web site and didn't uncover a trove of white papers. If you could post some URL's that would be appreciated. You don't have to worry about being less accurate than GPS. I mean, there are often far more important factors than nanosecond precision. > > To that point ( as accurate as GPS ) ….. GPS is simply a convent comparison system. Saying that > this or that is better or worse at this or that tau is *not* the same as saying it has more or less value. > It’s simply a system that is out there to be compared to. > > Bob > > >> You didn't mention pricing; it's hard to imagine it's as free as GPS so that seems like another disadvantage to me. >> >> Your comment about fewer satellites is spot on. That will be taken care of if you give SpaceX / Starlink a call and join that bandwagon. There are already 597 Starlink [1] satellites up there vs. 82 Iridium [2] satellites, yes? >> >> If you have entry-level / hobbyist grade evaluation kits I'm sure a number of us would be very interested to try it out. >> >> Thanks, >> /tvb >> >> [1] https://en.wikipedia.org/wiki/Starlink >> >> [2] https://en.wikipedia.org/wiki/Iridium_satellite_constellation >> >> >> On 8/9/2020 2:53 PM, Stewart Cobb wrote: >>> Taka Kamiya and Forrest Christian both asked recently about the alternative >>> satellite PNT system using the Iridium satellites. That system was >>> developed by my company, Satelles. It has been commercially available for >>> more than a year now. >>> >>> The biggest advantage is that our signal is at least 30 dB stronger than >>> GNSS signals (the exact numbers depend on whether you're talking to >>> engineering or marketing :). You can easily get a usable signal in deep >>> jungle, or a data center in the middle of a building's basement, or even >>> inside a locked shipping container. The stronger signal is correspondingly >>> more difficult to jam or spoof than GNSS, and our signal has anti-spoofing >>> features as well. >>> >>> The biggest disadvantage is that it is not quite as accurate as GPS, >>> because there are fewer satellites in view at any given time. >>> >>> I don't want to quote exact timing numbers here, because they depend a lot >>> on system integration details, but you can easily steer an OCXO within a >>> few hundred nanoseconds of USNO time. With a rubidium, you can do >>> considerably better. >>> >>> If you want to know more, our website is www.satellesinc.com. >>> >>> (If this message has been too commercial, I apologize in advance. The >>> boundary between information and salesmanship is not always sharp.) >>> >>> Cheers! >>> --Stu >>> _______________________________________________ >>> 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. > <First GPS.jpg><Side view GPS.jpg>_______________________________________________ > 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.

On Sunday, August 9, 2020, 9:21:23 PM EDT, Bob kb8tq <kb8tq@n1k.org <mailto:kb8tq@n1k.org>> wrote:  

Hi Oddly enough, the two share a direct connection: "Report on NBS Dual Mixeer Time Difference System (DMTD) Built for Time-Domain Measurements Associated with Phase 1 of GPS" https://tf.nist.gov/general/pdf/84.pdf <https://tf.nist.gov/general/pdf/84.pdf> Came out in Jan 1976 Starting in 1980, they had at least one paper a year on one or another aspect of GPS timing. The first one: ACCURATE TIME AND FREQUENCY TRANSFER DURING COMMON-VIEW OF A GPS SATELLITE https://tf.nist.gov/general/pdf/192.pdf <https://tf.nist.gov/general/pdf/192.pdf> Was the one that got a lot of people to sit up and notice GPS as a time source. Bob > On Aug 10, 2020, at 12:10 PM, ew <ewkehren@aol.com> wrote: > > I did attend those conferences, it was my first ex poser to Dual Mixer, NIST presented it for high precision frequency measurements. Still have copies of the proceedings.Time is and was key but I do not recall any papers addressing using GPS for time distribution as we know it today, and that is what I was responding to the question that I answered to. Also writing the proposals and attending all project reviews it was never covered. > > Bert Kehren > > > > In a message dated 8/10/2020 10:48:12 AM Eastern Standard Time, kb8tq@n1k.org writes: > > Hi > > From what I saw as the system was developed, the people doing it realized that timing > was at the core of the design. If there was a timing problem, nothing was going to work. > There were GPS (and before that other sat-nav) presentations at the Frequency Control > Symposium for many years. The “big boys” in timing all were involved in GPS one way > or the other. > > NIST was doing time transfer work on GPS before the system was fully up and running. > Their results are (to a great degree) what got everybody believing that GPS *could* > be a good source of time. Those papers started early and kept on flowing …. Until they > put their “stamp of approval” on the technique, I don’t think anybody was ready to call it > a super time source. > > This is by no means to imply that NIST was the only outfit involved or that the others > who also evaluated GPS somehow did not contribute. That’s far from the case. The only > point is that NIST got out there early. > > Bob > > > On Aug 10, 2020, at 5:09 AM, ew via time-nuts <time-nuts@lists.febo.com <mailto:time-nuts@lists.febo.com>> wrote: > > > > Attached are two pictures from my TI days as program Manager of the first GPS. There was no discussions of consumer use or timing application. Focus was on military application being able to guide a bomb in to a chimney. The cost per device was $ 300 000. Because of my high security clearance I was asked to brief the NSA and CIA on the future of GPS equipment. With my semiconductor background Moores Law and previously involved in consumer calculator development I predicted the size of a brick and $ 3000. I was declared the company Idiot lost all credibility as a strategic thinker ans subsequently left TI. When Magellan came out with there handheld unit they remembered me and send me one. Still have it. When two years later the units the size of a cigarette pack came out and where given away if you took a Cadillac test drive the asked for it back. I refused. History.Bert Kehren In a message dated 8/9/2020 11:23:33 PM Eastern Standard Time, time-nuts@lists.febo.com <mailto:time-nuts@lists.febo.com> writes: > > I've done some quick research. I do not see timing as one of the services provided. I wonder if it can be achieved by just listening into what's already transmitted (like GPS) and do some math on our side. > > > > On more broader sense, was GPS originally designed to provide timing service? Or is it a byproduct of needing to measure location and speed, thus it needed a constant signal, and that using it to sync reference signal is just an ancillary and after-thought use cases? > > > > --------------------------------------- > > (Mr.) Taka Kamiya > > KB4EMF / ex JF2DKG > > > > > > On Sunday, August 9, 2020, 9:21:23 PM EDT, Bob kb8tq <kb8tq@n1k.org <mailto:kb8tq@n1k.org>> wrote: > > > > Hi > > > > > > > >> On Aug 9, 2020, at 7:03 PM, Tom Van Baak <tvb@LeapSecond.com <mailto:tvb@LeapSecond.com>> wrote: > >> > >> Hi Stu, > >> > >> There's no problem with a semi-commercial posting here. You've been a member for a decade and frequent contributor plus the subject matter is exactly on-topic. So thanks for posting. > >> > >> I spent a while on your web site and didn't uncover a trove of white papers. If you could post some URL's that would be appreciated. You don't have to worry about being less accurate than GPS. I mean, there are often far more important factors than nanosecond precision. > > > > To that point ( as accurate as GPS ) ….. GPS is simply a convent comparison system. Saying that > > this or that is better or worse at this or that tau is *not* the same as saying it has more or less value. > > It’s simply a system that is out there to be compared to. > > > > Bob > > > > > >> You didn't mention pricing; it's hard to imagine it's as free as GPS so that seems like another disadvantage to me. > >> > >> Your comment about fewer satellites is spot on. That will be taken care of if you give SpaceX / Starlink a call and join that bandwagon. There are already 597 Starlink [1] satellites up there vs. 82 Iridium [2] satellites, yes? > >> > >> If you have entry-level / hobbyist grade evaluation kits I'm sure a number of us would be very interested to try it out. > >> > >> Thanks, > >> /tvb > >> > >> [1] https://en.wikipedia.org/wiki/Starlink <https://en.wikipedia.org/wiki/Starlink> > >> > >> [2] https://en.wikipedia.org/wiki/Iridium_satellite_constellation <https://en.wikipedia.org/wiki/Iridium_satellite_constellation> > >> > >> > >> On 8/9/2020 2:53 PM, Stewart Cobb wrote: > >>> Taka Kamiya and Forrest Christian both asked recently about the alternative > >>> satellite PNT system using the Iridium satellites. That system was > >>> developed by my company, Satelles. It has been commercially available for > >>> more than a year now. > >>> > >>> The biggest advantage is that our signal is at least 30 dB stronger than > >>> GNSS signals (the exact numbers depend on whether you're talking to > >>> engineering or marketing :). You can easily get a usable signal in deep > >>> jungle, or a data center in the middle of a building's basement, or even > >>> inside a locked shipping container. The stronger signal is correspondingly > >>> more difficult to jam or spoof than GNSS, and our signal has anti-spoofing > >>> features as well. > >>> > >>> The biggest disadvantage is that it is not quite as accurate as GPS, > >>> because there are fewer satellites in view at any given time. > >>> > >>> I don't want to quote exact timing numbers here, because they depend a lot > >>> on system integration details, but you can easily steer an OCXO within a > >>> few hundred nanoseconds of USNO time. With a rubidium, you can do > >>> considerably better. > >>> > >>> If you want to know more, our website is www.satellesinc.com. > >>> > >>> (If this message has been too commercial, I apologize in advance. The > >>> boundary between information and salesmanship is not always sharp.) > >>> > >>> Cheers! > >>> --Stu > >>> _______________________________________________ > >>> time-nuts mailing list -- time-nuts@lists.febo.com <mailto:time-nuts@lists.febo.com> > >>> To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com <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 <mailto:time-nuts@lists.febo.com> > >> To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com <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 <mailto:time-nuts@lists.febo.com> > > To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com <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 <mailto:time-nuts@lists.febo.com> > > To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com <http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com> > > and follow the instructions there. > > <First GPS.jpg><Side view GPS.jpg>_______________________________________________ > > > time-nuts mailing list -- time-nuts@lists.febo.com <mailto:time-nuts@lists.febo.com> > > To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com <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 <mailto:time-nuts@lists.febo.com> > To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com <http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com> > and follow the instructions there.

Allow me to clarify my GPS involvement. In 1973 TI moved me from Houston to Dallas to be part of the start up of calculators. This was followed by Marine projects since our chairman was an avid sailor. While working on Loran C my boss walked in one day and told me that at a staff meeting he had volunteered me to write the GPS proposals. It took me three days to convince him that this was not just sitting down and writing a proposal. It took over a month to get a team together of experts with at least order of magnitude more skills than me. I spend most my time on Pert Charts and reviews. Some coordination with Semiconductor on C and P code chips and SBP9900 bipolar 16 bit microprocessor. Cost calculation, lost our shirt on underestimating software development a first of this magnitude in TI Equipment Group (Military). We bid on two, did win both and I was given the choice which one. I picked Manpack. More top notch experts where added. Continued with typical program management. Do not recall any innovating technical contributions beside packaging. Bert Kehren