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 <kb...@n1k.org> > wrote: > > Hi > > > > > On Aug 9, 2020, at 7:03 PM, Tom Van Baak <t...@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- _______________________________________________ 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.