NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: True Distance vs. Observed Distance
From: Bill B
Date: 2012 Sep 17, 15:40 -0400
From: Bill B
Date: 2012 Sep 17, 15:40 -0400
On 9/17/2012 3:09 PM, Marcel Tschudin wrote: > I like your drawing skills, especially the ship ;-) Greg Indeed an interesting image. IMHO it would be useful to the novice to add arcs from the horizon through the bodies up to the zenith, and a straight line perpendicular to the horizon up to the zenith. When I first started down the cel nav portion of my bucket list, Frank and I had a low-heat-to-light debate regarding refraction to the zenith. His contention was, as I recall, that refraction always moved on a straight line up to the zenith. My position was, sure, but only for one body when facing it. With two bodies a "camera view" of their meridians would look like arcs. Eventually we reconciled this, confusion probably due to frame of reference and semantics. Nonetheless, confusing to a beginner. Bill B
