NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
From: Brad Morris
Date: 2012 Oct 23, 16:47 -0700
Hi Kevin
I have been thinking about your great circle course & the following occurs to me.
Twilight, for this time of year and at N40 Latitude, is on the order of 30 minutes. Lets double that to be safe, so 1 hour.
The deviation between a true, constantly curved great circle course and a straight line approximation will be far less than your measurement uncertainty, especially for a running fix whose total duration is less than one hour.
In other words, I would not worry about it and just assume a straight line course, instead of a curved course.
Regards
Brad
Greg,
I was referring to hours run.
And my shooting technique is probably in need of practice and refinement.
I think a good round of shots would probably be a lot more useful than a running fix.
It would be intersting to know what the SEALAND SL-7 navigators did when they were cruising at 30 knots. They had LORAN A and C, OMEGA and DECCA but probably had 1 or 2 days in the Atlantic and 3 or 4 days in the Pacific of pure celestial nav.Best Rgds,
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