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<div><a>Arlindo</a></div>
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<div><font size="2" face="tahoma">Thank you for taking the time to review the results.</font></div>
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<div><font size="2" face="tahoma">I did not know that GrADS<a></a> uses a spherical model with a single radius like the NCEP<a></a> sphere.</font></div>
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<div><font size="2" face="tahoma">That puts a whole new light on the issue.</font></div>
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<div><font size="2" face="tahoma">Let me do some additional research.</font></div>
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<div><font size="2" face="tahoma">John</font></div>
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<font color="#000000" size="2" face="Tahoma"><b>From:</b> gradsusr-bounces@gradsusr.org [gradsusr-bounces@gradsusr.org] On Behalf Of Arlindo da Silva [dasilva@alum.mit.edu]<br>
<b>Sent:</b> Monday, April 25, 2011 7:59 PM<br>
<b>To:</b> GrADS Users Forum<br>
<b>Subject:</b> Re: [gradsusr] Question on the use of PDEF for Lambert Conformal Conic mapping<br>
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<div>On Wed, Apr 20, 2011 at 5:02 PM, Huddleston, John <span dir="ltr"><<a href="mailto:Huddleston@cira.colostate.edu">Huddleston@cira.colostate.edu</a>></span> wrote:<br>
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<p class="MsoNormal">Hi</p>
<p class="MsoNormal"> </p>
<p class="MsoNormal">Attached are two images of the same data, one is a close up view and one is a view from space.</p>
<p class="MsoNormal"> </p>
<p class="MsoNormal">The grid was made by taking the Lambert Conformal Conic grid in meters and projecting it to Mercator for display in Google earth.</p>
<p class="MsoNormal"> </p>
<p class="MsoNormal">The sample data set was plotted with GrADS using PDEF to transform it again for display in Google earth.</p>
<p class="MsoNormal"> </p>
<p class="MsoNormal">The view from space looks correct.</p>
<p class="MsoNormal"> </p>
<p class="MsoNormal">The close up view shows the GrADS grid cells vertically up and down and they do not match the LCC grid.</p>
<p class="MsoNormal"> </p>
<p class="MsoNormal">Is this the correct behavior for the plot?</p>
<p class="MsoNormal"> </p>
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<div>I know that real cartographers uses an oblate model of the earth surface (with 2 radius) to improve accuracy at regional scales, while grads uses a spherical model with a single radius. Could you be reaching this limit where the oblateness effects are
important?</div>
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<div> Arlindo</div>
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<p class="MsoNormal">John Huddleston </p>
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-- <br>
Arlindo da Silva<br>
<a href="mailto:dasilva@alum.mit.edu">dasilva@alum.mit.edu</a><br>
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