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Re: Why are NA sight reduction tables not popular?
From: Gary LaPook
Date: 2012 Apr 8, 15:50 -0700
From: Gary LaPook
Date: 2012 Apr 8, 15:50 -0700
Now that I have looked at those pages in my N.A. I am again left scratching my head as to how somebody can come up with unnecessarily complicated ways to express simple things. The N.A. implementation of he law of cosines formula is: S= sin Dec C = cos Dec cos LHA Hc = arc sin (S sin Lat + C cos Lat) Hunh? What's wrong with the way we all learned it: sin Hc = (sin Lat sin Dec + cos Lat cos Dec cos LHA) And the N.A. azimuth formula implementation: X = (S cos Lat - C sin Lat)/cos Hc If X > +1 set X = +1 If X < -1 set X = -1 A = arc cos X Which is the equivalent of : cos A = (sin Dec cos Lat - cos Lat cos LHA)/cos Hc instead the standard: sin A = sec Hc cos Dec sin LHA Where do they find those people at the N.A. office? gl --- On Sun, 4/8/12, slk1000@aol.com <slk1000@aol.com> wrote:
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