A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
From: Greg Rudzinski
Date: 2014 Jul 3, 09:39 -0700
A technique to try on your next Doniol trial.
Before making an observation:
- select a DR assumed position
- determine declination and plot azimuth through DR.
- calculate azimuth by pocket slide rule using classic formula entered with rough Hs, LHA(t) and declination for time of DR (no need to be precise on this).
- Sum Cos(L-d) + Cos(L+d)
All that remains is observation LHA haversine product, cosine sum, and inverse sine for Hc to compare to Ho for intercept. Plotting is instant.