<HTML dir=ltr><HEAD><TITLE>Re: [Proj] trying to understand results of reprojecting from epsg 4326 to epsg 31370</TITLE>
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<DIV dir=ltr><FONT face="Times New Roman" color=#000000 size=2>There are two different geodetic conventions to the sense of the rotations used for 7-parameter transformations. There is the right-handed rule used by the Americans and the Australians, and the left-handed rule used by the Europeans. </FONT></DIV>
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<DIV dir=ltr><FONT size=2>Explanations regarding which is "correct" generally deteriorate into ethnocentric insults ... :-)</FONT></DIV>
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<DIV dir=ltr><FONT size=2>Cliff Mugnier</FONT></DIV>
<DIV dir=ltr><FONT size=2>LOUISIANA STATE UNIVERSITY</FONT></DIV></DIV>
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<FONT face=Tahoma size=2><B>From:</B> proj-bounces@lists.maptools.org on behalf of Moritz Lennert<BR><B>Sent:</B> Tue 07-Jul-09 11:00<BR><B>To:</B> PROJ.4 and general Projections Discussions<BR><B>Subject:</B> Re: [Proj] trying to understand results of reprojecting from epsg 4326 to epsg 31370<BR></FONT><BR></DIV>
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<P><FONT size=2>On 07/07/09 16:56, Noel Zinn wrote:<BR>> Consider changing the signs of the three rotations if you can do that<BR>> manually, or the rotation sense of the 7-parameter transformation.<BR><BR>That was it. Thanks also to Clifford for the same hint. Could someone<BR>explain the logic to me ? Why negate the translation, but not the<BR>rotation compared to the WGS84->Bel72 transformation ?<BR><BR>And: should the information linked to EPSG code 31370 be corrected ? How<BR>should I go about doing this ?<BR><BR>Moritz<BR>_______________________________________________<BR>Proj mailing list<BR>Proj@lists.maptools.org<BR><A href="http://lists.maptools.org/mailman/listinfo/proj">http://lists.maptools.org/mailman/listinfo/proj</A><BR></FONT></P></DIV></BODY></HTML>