A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
From: Robin Stuart
Date: 2020 May 16, 07:08 -0700
You wrote: "in a retro-azimuthal projection straight lines joining any point to the designated centre is an isoazimuth to the designated centre".
This is exactly correct but to quote from my trusty copy of Flattening the Earth by John P. Snyder, "The Littrow projection exceeds this requirement by also being conformal and by permitting the direct measurement of azimuth from any point on the map to any point point along the central meridian, instead of just to one point." As noted in an earlier post this feature forms the basis for Weir's Azimuth Diagram,