Both the sextant and the slide rule will still function after an EMP event. Not much other electronic stuff will. --- Graham / KE9H
== On Mon, Oct 26, 2015 at 4:20 PM, paul swed <paulsw...@gmail.com> wrote: > Crazy bit of humor/timing in all of this I guess. > > Oddly at the last MIT flea I picked up a very nice astro-compass including > case and manual. Also a news clipping that the Navy was restarting training > on celestial navigation. Now I just need to add a mount to the car dash > board. > All prepared for the day the Glenda GPS fails. > > By the way if its celestial navigation, next will be slide rules. Pretty > hard to tamper with them. The only virus they get are cold. > Regards > Paul > WB8TSL > Sorry really going astray here. > > On Mon, Oct 26, 2015 at 12:52 PM, Scott McGrath <scmcgr...@gmail.com> > wrote: > > > Or with the appropriate filters you can shoot the sun with a sextant like > > the old time Mariners did > > I still have a sextant and still use it along with a copy of Bowditch > > > > Content by Scott > > Typos by Siri > > > > > On Oct 26, 2015, at 9:13 AM, Jim Lux <jim...@earthlink.net> wrote: > > > > > >> On 10/25/15 9:37 AM, jim s wrote: > > >> > > >> Somewhat time related. The Navy realizes that GPS might not always > > >> work. I don't imagine that aircraft in the US Air Force will be able > to > > >> do this very reliably, and the article doesn't mention that service. > I'm > > >> guessing that a lot of strategic Air Force aircraft have star trackers > > >> that will work some of the time w/o GPS (at night). > > > > > > There's an excellent set of CD-ROMs with about 50 papers on celestial > > nav and time keeping from the Institute of Navigation. > > > > > > https://www.ion.org/publications/upload/CelestialNavTOC.pdf > > > > > > Papers in there about all manner of star trackers and celestial nav, > > from prehistory through the Renaissance era, to modern computerized > > celestial nav boxes, etc. > > > > > > $50, as I recall. > > > > > > Celestial nav during the daytime isn't all that hard, if you have a > > suitable telescope. With a 28x telescope on a theodolite, you can see > > Polaris, for instance. The trick is in finding it first. > > > > > > > > > > > >> > > > http://www.latimes.com/nation/la-na-celestial-navigation-20151025-story.html > > >> > > >> > > >> Thanks > > >> Jim > > >> _______________________________________________ > > >> time-nuts mailing list -- time-nuts@febo.com > > >> To unsubscribe, go to > > >> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > > >> and follow the instructions there. > > > > > > _______________________________________________ > > > time-nuts mailing list -- time-nuts@febo.com > > > To unsubscribe, go to > > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > > > and follow the instructions there. > > _______________________________________________ > > time-nuts mailing list -- time-nuts@febo.com > > To unsubscribe, go to > > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > > and follow the instructions there. > > > _______________________________________________ > time-nuts mailing list -- time-nuts@febo.com > To unsubscribe, go to > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. > _______________________________________________ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.