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<DIV><FONT face="Courier New" color=#000000 size=2>Hi list,</FONT></DIV>
<DIV><FONT face="Courier New" size=2></FONT> </DIV>
<DIV><FONT face="Courier New" size=2>(Apologies for sending HTML email - I'm stuck on OWA ...)</FONT></DIV>
<DIV><FONT face="Courier New" size=2></FONT> </DIV>
<DIV><FONT face="Courier New" size=2>I'm trying to reproject data in an obsolete Danish orthogonal projection called System34 in MapServer. To this end, I've found a .prj file for ArcMap distributed by the Danish National Survey & Cadastre, which defines the following parameters:</FONT></DIV>
<DIV><FONT face="Courier New" size=2></FONT> </DIV>
<DIV><FONT face="Courier New" size=2>PROJCS["Approximation of non-projective System 34 Sjælland",</FONT></DIV>
<DIV><FONT face="Courier New" size=2> GEOGCS["GCS_WGS_1984",</FONT></DIV>
<DIV><FONT size=2><FONT face="Courier New"> DATUM["D_WGS_1984", S</FONT><FONT face="Courier New">PHEROID["WGS_1984",6378137.0,298.257223563]</FONT><FONT face="Courier New">],</FONT></FONT></DIV>
<DIV><FONT face="Courier New" size=2> PRIMEM["Greenwich",0.0],</FONT></DIV>
<DIV><FONT face="Courier New" size=2> UNIT["Degree",0.0174532925199433]</FONT></DIV>
<DIV><FONT face="Courier New" size=2> ],</FONT></DIV>
<DIV><FONT face="Courier New" size=2> PROJECTION["Orthographic"],</FONT></DIV>
<DIV><FONT face="Courier New" size=2> PARAMETER["False_Easting",-100000.0],</FONT></DIV>
<DIV><FONT face="Courier New" size=2> PARAMETER["False_Northing",100000.0],</FONT></DIV>
<DIV><FONT face="Courier New" size=2> PARAMETER["Longitude_Of_Center",12.105661],</FONT></DIV>
<DIV><FONT face="Courier New" size=2> PARAMETER["Latitude_Of_Center",55.29235],</FONT></DIV>
<DIV><FONT face="Courier New" size=2> UNIT["Meter",1.0]</FONT></DIV>
<DIV><FONT face="Courier New" size=2>]</FONT></DIV>
<DIV><FONT face="Courier New" size=2></FONT> </DIV>
<DIV><FONT face="Courier New" size=2>To get MapServer to reproject my data, I added the following code to ms4w\proj\nad\epsg:</FONT></DIV>
<DIV><FONT face="Courier New" size=2></FONT> </DIV>
<DIV><FONT face="Courier New" size=2><34005> +proj=ortho +lat_0=55.29235 +lon_0=12.105661 +x_0=-100000.0 +y_0=100000.0</FONT></DIV>
<DIV><FONT face="Courier New" size=2></FONT> </DIV>
<DIV><FONT face="Courier New" size=2>Problem is that this transposes the data many kilometres north and slightly west (and perhaps also distorts it slightly, I'm not sure). The effect can be seen in these three maps:</FONT></DIV>
<DIV><FONT face="Courier New" size=2></FONT> </DIV><FONT face="Courier New" size=2><A href="http://quovadis.dk/img/proj/">http://quovadis.dk/img/proj/</A></FONT>
<DIV><FONT face="Courier New" size=2></FONT> </DIV>
<DIV><FONT size=2><FONT face="Courier New">All three maps are drawn in EPSG:32632. The green line data is natively EPSG:32632. The blue points are fetched from a WMS service in EPSG:4326, EPSG:32632 and my custom transformation respectively. The difference between lat/lon and UTM is noticeable but acceptable, but my own projection is way off. I have confirmed the distortion with different data sources in System 34 - this WMS and an orthophoto from another source - so I'm certain the error is on my end. </FONT><FONT face="Courier New">Can anybody tell me which rookie mistake I've commited? ;-)</FONT></FONT></DIV>
<DIV><FONT face="Courier New" size=2></FONT> </DIV>
<DIV><FONT face="Courier New" size=2></FONT> </DIV>
<DIV><FONT face="Courier New" size=2></FONT> </DIV>
<DIV><FONT face="Courier New" size=2>best regards,</FONT></DIV>
<DIV><FONT face="Courier New" size=2>Kristian Thy</FONT></DIV><br><br>
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