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A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: All Haversine Fix
From: Tony Oz
Date: 2019 May 11, 07:48 -0700
From: Tony Oz
Date: 2019 May 11, 07:48 -0700
Hello!
I once asked if it is possible calculate a "direct" fix (from two altitudes) using Haversines only. Lars Bergman was kind to provide an example here (http://fer3.com/arc/m2.aspx/All-Haversine-Fix-Bergman-sep-2018-g42693).
I played with it - seems no alterations or amendments are required, it works just fine if three simple rules are followed:
- N;E - positive, S;W - negative
- p1 should be calculated off the Northern Pole
- the "second" body (which GHA is used for Lon) should preferably be to the west (t2 to be positive), which will simplify the last step
The accuracy with the 4-place NatHav table is reasonable - mostly within 3-:-5 arcminutes off.
Lars, HUGE thanks again!
Warm regards,
Tony
60°N 30°E
