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<body bgcolor="#FFFFFF"><div>In Snyder's book, "Map Projections: A Working Manual", the symbol k stands for the local scale factor, and you can find formulas for k for an ellipsoid-based LCC projection at the top of page 108. </div><div><br></div><div><a href="http://pubs.er.usgs.gov/publication/pp1395">http://pubs.er.usgs.gov/publication/pp1395</a></div><div><br></div><div>It may be possible to compute k with Proj.4, but I don't know how to do that. </div><div><br></div><div>Regards,</div><div><br></div><div>Mikael Rittri</div><div>Carmenta</div><div>Sweden</div><div><a href="http://www.carmenta.com">http://www.carmenta.com</a></div><div><br>28 dec 2012 kl. 20:44 skrev "Achim Hasenmueller" <<a href="mailto:achim.hasenmueller@gmail.com">achim.hasenmueller@gmail.com</a>>:<br><br></div><div></div><blockquote type="cite"><div><div dir="ltr"><span style="font-size:13px;font-family:Georgia">Hi,</span><br style="font-size:13px;font-family:Georgia"><br style="font-size:13px;font-family:Georgia"><span style="font-size:13px;font-family:Georgia">I'm interested in finding the relationship between scale factors of LCC maps</span><br style="font-size:13px;font-family:Georgia">
<span style="font-size:13px;font-family:Georgia">(aviation) that are designed so they can be put next to each other and therefore</span><br style="font-size:13px;font-family:Georgia"><span style="font-size:13px;font-family:Georgia">have a different scale factor each.</span><br style="font-size:13px;font-family:Georgia">
<br style="font-size:13px;font-family:Georgia"><span style="font-size:13px;font-family:Georgia">The maps cover parts of Europe with standard parallels at 40°N and 52°N. The</span><br style="font-size:13px;font-family:Georgia">
<span style="font-size:13px;font-family:Georgia">scale factor differs slightly and I am interested in a formula to calculate it.</span><br style="font-size:13px;font-family:Georgia"><span style="font-size:13px;font-family:Georgia">I have found this in a forum message from 2007:</span><br style="font-size:13px;font-family:Georgia">
<br style="font-size:13px;font-family:Georgia"><span style="font-size:13px;font-family:Georgia">"Find a chart that gives the true scale at 54ºN and divide that into 500,000.</span><br style="font-size:13px;font-family:Georgia">
<span style="font-size:13px;font-family:Georgia">This is the scale factor. For 51N the scale factor is 500/515=0.9709, = 1/1.03</span><br style="font-size:13px;font-family:Georgia"><span style="font-size:13px;font-family:Georgia">Running Hooijberg's algorith for LCC, 2 parallels, the scale factor at</span><br style="font-size:13px;font-family:Georgia">
<span style="font-size:13px;font-family:Georgia">54N=0.97005."</span><br style="font-size:13px;font-family:Georgia"><br style="font-size:13px;font-family:Georgia"><span style="font-size:13px;font-family:Georgia">Unfortunately a search for Hooijberg's algorithm was not successful. Any</span><br style="font-size:13px;font-family:Georgia">
<span style="font-size:13px;font-family:Georgia">pointers appreciated!</span><br style="font-size:13px;font-family:Georgia"><br style="font-size:13px;font-family:Georgia"><span style="font-size:13px;font-family:Georgia">Thanks!</span><br style="font-size:13px;font-family:Georgia">
<span style="font-size:13px;font-family:Georgia">Achim</span></div>
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