For those of us who would have to navigate a long way, there is a on-line http://timeandnavigation.si.edu/
Robert G8RPI. ________________________________ From: Jim Lux <[email protected]> To: Discussion of precise time and frequency measurement <[email protected]> Sent: Monday, 1 July 2013, 13:56 Subject: [time-nuts] Smithsonian Time/Nav Exhibit I had a chance to go through the Time and Navigation exhibit at the National Air and Space Museum last week. From a "time" standpoint, there's probably not much there that time-nuts don't know already, but it's kind of cool to see cleaned up examples of equipment from days gone by. (there's an old cesium beam from NIST on display, and a Symmetricom cesium turned on and counting, but also a lot of old GPS stuff... lots of Rb and Cs for space) Quite a lot of the exhibit space was devoted to the problem of air navigation, which, now that I've seen the exhibit, I can understand what challenge it was. Over centuries, folks had figured out how to navigate on ships and on land, but those are inherently slow moving, so you can do things like take multiple sextant sights and reduce them. But planes move fast, so you don't have as much time to do it. It took real guts to be the navigator in the little cockpit out front of the plane, taking sights with your body out in the wind. And the poor fellow who was sucked out of a plane when taking sights standing on his seat and the astrodome blew out. It was interesting to see how many different schemes were used for (mostly radio based) nav in airplanes over a fairly short time. Low Frequency DF, A/N Ranges, VOR, LORAN, etc. I didn't see Omega. They have an inertial nav unit there from a sub, but not much explanation of how inertial nav works. They talk about the DSN (and actually have a 4 bay rack of the old time/frequency distribution gear on display), but not much discussion on exactly how we do navigation for deep space. _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
