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<p class="MsoNormal"><font size="2" face="Arial"><span lang="EN-US" style="font-size:
10.0pt;font-family:Arial">Hello,<o:p></o:p></span></font></p>
<p class="MsoNormal"><font size="2" face="Arial"><span lang="EN-US" style="font-size:
10.0pt;font-family:Arial">I am reading the specification for CADRG,
<o:p></o:p></span></font></p>
<p class="MsoNormal"><font size="2" face="Arial"><span lang="EN-US" style="font-size:
10.0pt;font-family:Arial"><a href="http://earth-info.nga.mil/publications/specs/printed/89038/89038_CADRG.pdf">http://earth-info.nga.mil/publications/specs/printed/89038/89038_CADRG.pdf</a>
. <o:p></o:p></span></font></p>
<p class="MsoNormal"><font size="2" face="Arial"><span lang="EN-US" style="font-size:
10.0pt;font-family:Arial">But I am confused about the polar areas.
<o:p></o:p></span></font></p>
<p class="MsoNormal"><font size="2" face="Arial"><span lang="EN-US" style="font-size:
10.0pt;font-family:Arial"><o:p> </o:p></span></font></p>
<p class="MsoNormal" style="text-autospace:none"><font size="2" face="Arial"><span lang="EN-US" style="font-size:10.0pt;font-family:Arial">Section 3.5.5 says: “</span></font><font size="2" face="Courier"><span lang="EN-US" style="font-size:10.5pt;font-family:Courier">CADRG
shall use a polar stereographic projection</span></font><font size="2" face="Arial"><span lang="EN-US" style="font-size:10.0pt;font-family:Arial">“.</span></font><font size="2" face="Courier"><span lang="EN-US" style="font-size:10.5pt;font-family:Courier">
<o:p></o:p></span></font></p>
<p class="MsoNormal" style="text-autospace:none"><font size="2" face="Courier"><span lang="EN-US" style="font-size:10.5pt;font-family:Courier"><o:p> </o:p></span></font></p>
<p class="MsoNormal" style="text-autospace:none"><font size="2" face="Arial"><span lang="EN-US" style="font-size:10.0pt;font-family:Arial">And Section 3.5.6 says “</span></font><font size="2" face="Courier"><span lang="EN-US" style="font-size:10.5pt;font-family:Courier">Polar
frames are defined in polar stereographic<o:p></o:p></span></font></p>
<p class="MsoNormal" style="text-autospace:none"><font size="2" face="Courier"><span lang="EN-US" style="font-size:10.5pt;font-family:Courier">projection and non-polar frames are in the ARC projection.</span></font><font size="2" face="Arial"><span lang="EN-US" style="font-size:10.0pt;font-family:Arial">“<o:p></o:p></span></font></p>
<p class="MsoNormal" style="text-autospace:none"><font size="2" face="Arial"><span lang="EN-US" style="font-size:10.0pt;font-family:Arial"><o:p> </o:p></span></font></p>
<p class="MsoNormal" style="text-autospace:none"><font size="2" face="Arial"><span lang="EN-US" style="font-size:10.0pt;font-family:Arial">But Section 3.6.2 says: “</span></font><font size="2" face="Courier"><span lang="EN-US" style="font-size:10.5pt;font-family:Courier">Pixel
coordinates in the polar zones are <o:p></o:p></span></font></p>
<p class="MsoNormal" style="text-autospace:none"><font size="2" face="Courier"><span lang="EN-US" style="font-size:10.5pt;font-family:Courier">proportional to rectangular coordinates of the Azimuthal<o:p></o:p></span></font></p>
<p class="MsoNormal" style="text-autospace:none"><font size="2" face="Courier"><span lang="EN-US" style="font-size:10.5pt;font-family:Courier">Equidistant projection, polar aspect, spherical form (as<o:p></o:p></span></font></p>
<p class="MsoNormal" style="text-autospace:none"><font size="2" face="Courier"><span lang="EN-US" style="font-size:10.5pt;font-family:Courier">defined in
</span></font><i><font size="3" face="Courier"><span lang="EN-US" style="font-size:11.5pt;font-family:Courier;
font-style:italic">Map Projections–A Working Manual,
</span></font></i><font size="2" face="Courier"><span lang="EN-US" style="font-size:10.5pt;font-family:Courier">page 191).</span></font><font size="2" face="Arial"><span lang="EN-US" style="font-size:
10.0pt;font-family:Arial">“</span></font><font size="2" face="Courier"><span lang="EN-US" style="font-size:10.5pt;font-family:Courier"><o:p></o:p></span></font></p>
<p class="MsoNormal" style="text-autospace:none"><font size="2" face="Arial"><span lang="EN-US" style="font-size:10.0pt;font-family:Arial"><o:p> </o:p></span></font></p>
<p class="MsoNormal" style="text-autospace:none"><font size="2" face="Arial"><span lang="EN-US" style="font-size:10.0pt;font-family:Arial">And section 30.1 says: “</span></font><font size="3" face="Courier"><span lang="EN-US" style="font-size:11.5pt;font-family:Courier">Polar
zone equations are based on <o:p></o:p></span></font></p>
<p class="MsoNormal" style="text-autospace:none"><font size="3" face="Courier"><span lang="EN-US" style="font-size:11.5pt;font-family:Courier">the Azimuthal Equidistant projection, polar aspect,
<o:p></o:p></span></font></p>
<p class="MsoNormal" style="text-autospace:none"><font size="3" face="Courier"><span lang="EN-US" style="font-size:11.5pt;font-family:Courier">spherical form.</span></font><font size="2" face="Arial"><span lang="EN-US" style="font-size:10.0pt;font-family:Arial">“<o:p></o:p></span></font></p>
<p class="MsoNormal" style="text-autospace:none"><font size="2" face="Arial"><span lang="EN-US" style="font-size:10.0pt;font-family:Arial"><o:p> </o:p></span></font></p>
<p class="MsoNormal" style="text-autospace:none"><font size="2" face="Arial"><span lang="EN-US" style="font-size:10.0pt;font-family:Arial">Since Polar Stereographic is not the same thing as Azimuthal Equidistant
<o:p></o:p></span></font></p>
<p class="MsoNormal" style="text-autospace:none"><font size="2" face="Arial"><span lang="EN-US" style="font-size:10.0pt;font-family:Arial">in polar aspect, I assume that one of the two alternatives is just a typo
<o:p></o:p></span></font></p>
<p class="MsoNormal" style="text-autospace:none"><font size="2" face="Arial"><span lang="EN-US" style="font-size:10.0pt;font-family:Arial">(unless I am missing something). But which one is the typo of <o:p></o:p></span></font></p>
<p class="MsoNormal" style="text-autospace:none"><font size="2" face="Arial"><span lang="EN-US" style="font-size:10.0pt;font-family:Arial">“Stereographic” and “Azimuthal Equidistant”? Does anyone know?
<o:p></o:p></span></font></p>
<p class="MsoNormal" style="text-autospace:none"><font size="2" face="Arial"><span lang="EN-US" style="font-size:10.0pt;font-family:Arial"><o:p> </o:p></span></font></p>
<p class="MsoNormal" style="text-autospace:none"><font size="2" face="Arial"><span lang="EN-US" style="font-size:10.0pt;font-family:Arial">Best regards,<o:p></o:p></span></font></p>
<p class="MsoNormal" style="text-autospace:none"><font size="2" face="Arial"><span lang="EN-US" style="font-size:10.0pt;font-family:Arial"><o:p> </o:p></span></font></p>
<p class="MsoNormal" style="text-autospace:none"><font size="2" face="Arial"><span style="font-size:10.0pt;font-family:Arial">Mikael Rittri<o:p></o:p></span></font></p>
<p class="MsoNormal" style="text-autospace:none"><font size="2" face="Arial"><span style="font-size:10.0pt;font-family:Arial">Carmenta<o:p></o:p></span></font></p>
<p class="MsoNormal" style="text-autospace:none"><font size="2" face="Arial"><span style="font-size:10.0pt;font-family:Arial">Sweden<o:p></o:p></span></font></p>
<p class="MsoNormal" style="text-autospace:none"><font size="2" face="Arial"><span style="font-size:10.0pt;font-family:Arial">http://www.carmenta.com<o:p></o:p></span></font></p>
<p class="MsoNormal" style="text-autospace:none"><font size="2" face="Arial"><span style="font-size:10.0pt;font-family:Arial"><o:p> </o:p></span></font></p>
<p class="MsoNormal" style="text-autospace:none"><font size="3" face="Courier"><span style="font-size:11.5pt;font-family:Courier"><o:p> </o:p></span></font></p>
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