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<p style="line-height: 100%; margin-bottom: 0in">
The following is a link to a derivation of an ellipsoidal gnomonic
via ECEF that I did 12 years ago:</p>
<p style="line-height: 100%; margin-bottom: 0in"><a
href="http://www.hydrometronics.com/downloads/Ellipsoidal%20Gnomonic%20Projection.pdf"
class="moz-txt-link-freetext">http://www.hydrometronics.com/downloads/Ellipsoidal%20Gnomonic%20Projection.pdf</a></p>
<p style="line-height: 100%; margin-bottom: 0in">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? </p>
<p style="line-height: 100%; margin-bottom: 0in">Noel</p>
<p></p>
<div class="moz-cite-prefix">On 12/28/2022 3:59 PM, Clifford J
Mugnier wrote:<br>
</div>
<blockquote type="cite"
cite="mid:DM8P221MB0309224C55A091DDDC394206A8F29@DM8P221MB0309.NAMP221.PROD.OUTLOOK.COM"><font
size="2"><span style="font-size:11pt;">The spherical gnomonic
projection has the property that geodesics map to<br>
> straight lines.</span></font></blockquote>
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