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A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
From: Antoine Couëtte
Date: 2023 Oct 19, 01:41 -0700
Re : Dale Lichtbau's APEX COMPUTATION
Frank,
You have shown interest to solve our Apex problem submitted by Dale Lichtblau in the second part of his initial post through investigating "the distance to the horizon from an eye at a given height" .
Looks like you are fond of the "horizon depression formula" and are ready to use it anytime you can :-).
A few solutions have been published in which I would single out Lars Bergman's one which solves this subject through paper/pencil analytical computation.
Finally, Dale Lichtblau summarized all these results, stating "The 375.4ft. solution seems to be correct".
Although it's a bit late, in the attachment I am hereby submitting my paper/pencil analytical contribution which, as you can see, is extremely close from Lars' solution. It also fully matches the "official" result at 375' / 125 y.
Final remark :
We cannot use here the usual horizon depression formula Hd ' = 0.97 ' SQRT (Height in feet), but we are to use the full fledged geometrical solution α ' = 1.06 ' SQRT (Heigt in feet).
Kermit
