A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
From: Tony Oz
Date: 2021 Sep 1, 00:45 -0700
Recovering from my shameful blunder with the Lat - I re-did the whole process VERY carefully. Here is the plot a-la Wilson to obtain the LAN UT from the sights.
The no-tables idea in the method is to retire the Sun-setting graph according to the declination change and the distance travelled towards the Sun's GP during ΔWT - the time passed between the equal altitudes on both slopes (i.e. the moment of the intersection according to the "rising" and the "setting" timescales). The Δh is the altitude correction, Δh = (SOGNorthing - ΔDechourly)·ΔWT. The Sun-setting graph is paralleled to pass through that point, the new intersection is the true LAN, again calculated as the half-sum of the moments on both time scalles.
So, my amended LAN UT == 16:37:29; the fix for the LAN is Lat == 37°11,2'N; Lon == 70°11,7W.
And the DR1700 == 37°09,7'N|70°10,9'W.
Hope this time I did not fail. :)