NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
From: David Pike
Date: 2019 Jul 15, 09:18 -0700
Greg, Frank
This constant azimuth at sunrise for four days seemed hard to believe, because for the given situation, as you go north and as days pass the Sun ought to rise later each day, so the Sun’s azimuth should increase. However, you are also travelling west, so maybe that cancels things out. The only way to test it was to work out the DR position after four days and calculate the time at which the Sun’s LL will cross the horizon, which I did using the Air Almanac and AP3270 Vol 2. (see attached) Sure enough the azimuth is 080(T), so the PL lies along 350(T).
My question is, is there an inevitability in this because of the geometry of position circles or the fact that coAlt is 90 or is this simply a set up engineered by a suitable choice of date, DR position, destination, and only four days of sailing required. DaveP
.JPG "Click to enlarge.")
.JPG "Click to enlarge.")
