A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
From: Bob Goethe
Date: 2017 Dec 15, 18:40 -0800
On page 45 of John Karl's book, Celestial Navigation in the GPS age, he says that:
- Pub. 249 is tabulated to the nearest minute (an accuracy of +/- 0.5')
- Pub. 229 is tablulated to the nearest 0.1' (implying an accuracy of +/-0.05')
He goes on to say, "Unfortunately, that's not the case at all. The best H.O. 229 can do is +/-0.2', which compared to H.O. 249's +/-0.5' accuracy, is only marginally better."
I have pondered why this might be so...and have come up with nothing. I would appreciate Karl (or anybody else for that matter) unpacking this for me a bit.