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A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Longhand Calc's differ from Software Calc's
From: Marty Lyons
Date: 2014 Nov 15, 09:50 -0800
From: Marty Lyons
Date: 2014 Nov 15, 09:50 -0800
I took some sights and decided to reduce them longhand to stay in practice. I checked them with software. I find some significant differneces in the calculated altitudes. So I calculate some known correct sample problems longhand and compare to software, I find that the Hc's differ by 4-5 minutes. I am thinking this is pretty significant. I used the HO 229 longhand method and these websites for computer solutions.
http://aa.usno.navy.mil/cgi-bin/aa_flamenav.pl
http://www.celnav.de/sightred.htm
The two websites pretty much agree. The differences appear to be in the Hc. Any thoughts on why HO 229 method leads to different results than computer solutions?
