A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
From: Jim Williams
Date: 2020 Sep 27, 21:36 -0700
I think the azimuth will be northerly if SIN(Altitude)*SIN(Latitude) < SIN(Declination). Southerly if SIN(Altitude)*SIN(Latitude) > SIN(Declination).
I think you can be a little clever and use Hanno's original chart to determine this.
1. Mark the complement of the Altitude on the left side and draw horizontal line. (Complement being 90 minus Altitude.)
2. Mark the Latitude on the top and draw vertical line.
3. Find the intersection and following the curve up and to the right.
4. Take the complement of the angle on the right next to the end of the curve.
5. If Declination is greater than this angle, then azimuth is northerly, otherwise southerly. (Opposite for southern hemisphere.)