Hi Well…. there’s also the solar flare that vaporizes the planet earth :)
A flare big enough to take out all the sat systems would disrupt a lot more than just navigation. It also probably is big enough to take out HF radio gear as well. It takes a *lot* of energy to permanently take out a sat system. Hour or two disruptions … sure … total destruction, that’s getting into crazy levels. Bob > On Aug 12, 2018, at 7:29 PM, Dana Whitlow <[email protected]> wrote: > > How exactly does one get submillisecond time of day precision with a > sextant? > (even if sticks and pebbles are thrown into the mix) > I'd say more like ~1 sec precision on a really fine day, it the sextant is > wielded by > a skilled and practiced operator who has apriori knowledge of his location. > > And what about standard frequency dissemination? > > I'm also upset about the notion of time distribution and transfer by > internet. Now > there's a fine example of a system that could be brought down by a single > competent > hacker! > > And all it takes is one really good solar flare to bring down GPS (and > Glonass and > the others) semipermanently, if the reports I read are true. > > I argue that instead of shutting down distribution avenues, NIST should be > making > additional ones available. > > A lot has been said lately about how rapidly our technology is exploding. > But think > about how much of that is critically dependent on precision time transfer > over the > planet, and how much longer it would take mankind to recover from (insert > your favorite > disaster here) without good time and frequency transfer still up and > working. > > Dana > > > > > > On Sun, Aug 12, 2018 at 2:06 PM, djl <[email protected]> wrote: > >> all you need for a once a day noon fix is a level surface, a stick, and >> some pebbles. >> Don >> >> >> On 2018-08-12 08:29, Scott McGrath wrote: >> >>> And with dependence on GPS we have created a serious vulnerability as >>> too many critical pieces of infrastructure are dependent on a SINGLE >>> precision timing and positioning system. >>> >>> I can use a sextant and have a copy of Bowditch. But they only work >>> on clear days and nights. >>> >>> if GPS goes down for any reason. Whats the backup solution? >>> >>> >>> On Aug 10, 2018, at 2:25 PM, Lester Veenstra <[email protected]> wrote: >>> >>> Used to work with Wayne on two time transfer via satellite >>> Great guy >>> >>> >>> Lester B Veenstra K1YCM MØYCM W8YCM 6Y6Y >>> [email protected] >>> >>> Physical and US Postal Addresses >>> 5 Shrine Club Drive (Physical) >>> HC84 452 Stable Ln (RFD USPS Mail) >>> Keyser WV 26726 >>> GPS: 39.336826 N 78.982287 W (Google) >>> GPS: 39.33682 N 78.9823741 W (GPSDO) >>> >>> >>> Telephones: >>> Home: +1-304-289-6057 >>> US cell +1-304-790-9192 >>> Jamaica cell: +1-876-456-8898 >>> >>> >>> -----Original Message----- >>> From: time-nuts [mailto:[email protected]] On Behalf Of >>> Tom >>> Van Baak >>> Sent: Friday, August 10, 2018 10:19 AM >>> To: Discussion of precise time and frequency measurement >>> Subject: Re: [time-nuts] Bicentennial GOES satellite clock >>> >>> Tim, >>> >>> Thanks for posting that photo. That space age 1976 GOES clock caught our >>> eyes when the paper came out in 2005 (see also pages 11, 12, 13): >>> >>> https://tf.nist.gov/general/pdf/2013.pdf >>> >>> There was quite a bit of traffic on time-nuts around 2005 when the GOES >>> satellite time service was turned off (and back on, and off, and on, and >>> finally off for good). That left many of us with piles of 468 MHz GOES >>> receivers, antennae, clocks and led to efforts to re-create the RF signals >>> in-home so that GOES clocks would still work. There was even a commercial >>> G2G (GPS to GOES) translator. >>> >>> Anyway, I asked around about that one-off bicentennial clock in the photo >>> and neither the authors, NIST, or Smithsonian knows where it ended up. >>> There's tons of information on the GOES satellite system and GOES clocks >>> in >>> the NIST T&F archives: >>> >>> https://tf.nist.gov/general/publications.htm >>> >>> Best to search title for GOES, or search author for Hanson. It's a >>> fascinating glimpse into the recent past. Yes, it's sad that GOES (and >>> Omega, and Loran-C) aren't operational anymore, but GPS does such a better >>> job. Plus we now have cable, WiFi, cell phones, the internet, Iridium, >>> etc. >>> >>> If you wanted to build your own Bicentennial GOES Clock, the design was >>> published, including source code -- for its i4004 (!!) CPU. If you have >>> even >>> one minute to spare, see attached image and click on these two PDF's: >>> >>> "Satellite Controlled Digital Clock System (patent)" >>> https://tf.nist.gov/general/pdf/1791.pdf >>> >>> "A Satellite-Controlled Digital Clock (NBS TN-681)" >>> https://tf.nist.gov/general/pdf/452.pdf >>> >>> /tvb >>> >>> >>> ----- Original Message ----- >>> From: "Tim Shoppa" <[email protected]> >>> To: "Discussion of precise time and frequency measurement" >>> <[email protected]> >>> Sent: Wednesday, August 08, 2018 7:29 PM >>> Subject: [time-nuts] Bicentennial GOES satellite clock >>> >>> >>> See the groovy picture at >>>> https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4847573/figure/ >>>> f9-j110-2lom/ >>>> >>>> If anyone knows the whereabouts or history of the bicentennial GOES time >>>> clock display, please let me know! >>>> >>>> Tim N3QE >>>> >>> >>> >>> >>> _______________________________________________ >>> time-nuts mailing list -- [email protected] >>> To unsubscribe, go to >>> http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com >>> and follow the instructions there. >>> >>> _______________________________________________ >>> time-nuts mailing list -- [email protected] >>> To unsubscribe, go to >>> http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com >>> and follow the instructions there. >>> >> >> -- >> Dr. Don Latham >> PO Box 404, Frenchtown, MT, 59834 >> VOX: 406-626-4304 >> >> >> >> _______________________________________________ >> time-nuts mailing list -- [email protected] >> To unsubscribe, go to http://lists.febo.com/mailman/ >> listinfo/time-nuts_lists.febo.com >> and follow the instructions there. >> > _______________________________________________ > time-nuts mailing list -- [email protected] > To unsubscribe, go to > http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com > and follow the instructions there. _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
