<div dir="ltr"><div class="gmail_default" style="font-size:small">Hello,</div><div class="gmail_default" style="font-size:small"><br></div><div class="gmail_default" style="font-size:small">I can confirm the value of the radius used by GCTP if it helps any.</div><div class="gmail_default" style="font-size:small"><br></div><div class="gmail_default" style="font-size:small">Mike</div><div class="gmail_default" style="font-size:small"><br></div><div class="gmail_default" style="font-size:small"><br></div></div><div class="gmail_extra"><br><div class="gmail_quote">On Thu, Jul 7, 2016 at 9:00 AM, Ills <span dir="ltr"><<a href="mailto:mangahair@gmail.com" target="_blank">mangahair@gmail.com</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><br>
Thanks for all the replies and suggestions so far,<br>
<br>
After more testing, which shows that we can get identical results in proj4<br>
as GlobalMapper using a spheroid radius of 6367444.66m. This is the midpoint<br>
of the standard WGS84 semi-major (6378137) and semi-minor axes radii<br>
(6356752.3).<br>
<br>
This seems to be different from the normal mean earth radius used by GCTP<br>
(6370997).<br>
<br>
Waiting on a a reply from Blue Marble, loathing to think about all the data<br>
which could now be wrong and again thanking you all for your time.<br>
<br>
Ills<br>
<br>
<br>
<br>
--<br>
View this message in context: <a href="http://osgeo-org.1560.x6.nabble.com/Difference-in-Orthographic-projection-between-Proj4-and-Global-Mapper-tp5275097p5275198.html" rel="noreferrer" target="_blank">http://osgeo-org.1560.x6.nabble.com/Difference-in-Orthographic-projection-between-Proj4-and-Global-Mapper-tp5275097p5275198.html</a><br>
Sent from the PROJ.4 mailing list archive at Nabble.com.<br>
_______________________________________________<br>
Proj mailing list<br>
<a href="mailto:Proj@lists.maptools.org">Proj@lists.maptools.org</a><br>
<a href="http://lists.maptools.org/mailman/listinfo/proj" rel="noreferrer" target="_blank">http://lists.maptools.org/mailman/listinfo/proj</a><br>
</blockquote></div><br></div>