NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
From: Frank Reed
Date: 2023 Mar 13, 13:16 -0700
Andrés,
In your post earlier today, you included this images with "cones of position" terminating at points on the celestial sphere. Where is that from? It's clearly a professional illustration from a book dating back some decades. But it appears to me that the creator of the image has thoroughly misunderstood the concept. The cones are backwards.
I was getting ready to go digging for some of my old artwork on this concept, and then I noticed that you actually referenced one of my old webpages, http://fer3.com/cones/, on this concept dating back 17 years (so shockingly long ago that I grabbed my calculator to make sure that 2023-2006 actually equals 17!). A two-star fix understood as two circles of position on the Earth's surface can be extended off the surface of the Earth as two cones of position, but the "pointy ends" of those cones are at the Earth's center. The old diagram that you found with the cones' pointy ends on the stars on the "celestial sphere' really doesn't even make sense as a visual aid. It's an oddity!
Frank Reed
Clockwork Mapping / ReedNavigation.com
Conanicut Island USA
File:
