NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: Navigation without Leap Seconds
From: Richard M Pisko
Date: 2008 Apr 18, 21:38 -0600
From: Richard M Pisko
Date: 2008 Apr 18, 21:38 -0600
On Fri, 18 Apr 2008 01:00:44 -0600,wrote: > It would seem that most everyone here is in agreement that there would > be no > real problem for celestial navigation if leap seconds are abolished. Does > anyone disagree? Personally, I would be sorry to hear the double tick disappear from WWV. I have a surveying friend down in West Virginia who might rather take crossing lines of position than run a traverse or triangulations from a couple of distant monuments and build a new tower. The traditional navigation procedure would take multiple sights and tenths of seconds timing to get a better fix than the newer consumer grade GPS; but he can still do that in theory. Of course, setting up an RTK base station on a monument, and using professional equipment of that nature would be quicker, more accurate, and more expensive. The RTK is basically celestial navigation by machine software and radio connections, but is too modern, I think. For a more traditional surveying problem, determining azimuths from the sun, it is surprising how fast that sun moves off the crosshair intersections (simplified by using a Roeloffs prism). Those tenth of a second corrections from UTC to UT1 really are necessary for accuracy to the seconds of arc. Not so for Polaris shots, but then slight tilting of the telescope's horizontal axis combined with the high altitude of the star introduces errors not eliminated by transiting the scope . . . at least on the old optical theodolites I like . . . unless set with a well adjusted striding level. Still not Celestial *navigation*, but at least not very electronic. I thank Geoffrey Kolbe for his comments and link in Navlist 4878; and that DUT1 figure of about -0.38 seconds currently. I passed it on. -- Richard . . . Using Opera 9.2.4 after the "Dog" died --~--~---------~--~----~------------~-------~--~----~ Navigation List archive: www.fer3.com/arc To post, email NavList@fer3.com To , email NavList-@fer3.com -~----------~----~----~----~------~----~------~--~---