[PROJ] Ellipsoidal version of the gnomonic projection

[Noel Zinn]

The following is a link to a derivation of an ellipsoidal gnomonic via 
ECEF that I did 12 years ago:

http://www.hydrometronics.com/downloads/Ellipsoidal%20Gnomonic%20Projection.pdf

Being thoroughly retired now, and having donated my entire technical 
library to a university, I’m not in a position to test this ellipsoidal 
version against the criteria stated by Charles, namely “The spherical 
gnomonic projection has the property that geodesics map to straight 
lines”. That may, or may not, be true for this ellipsoidal version. But 
does that matter if this “ellipsoidal gnomonic is a direct perspective 
from the geocenter through the ellipsoid onto the tangential plane”, the 
same method of derivation of the spherical version?

Noel

On 12/28/2022 3:59 PM, Clifford J Mugnier wrote:
> The spherical gnomonic projection has the property that geodesics map to
> > straight lines.
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