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.
