<HTML dir=ltr><HEAD><TITLE>[Proj] How to transform between NAD83 HARN/HPGN and WGS84</TITLE>
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<DIV dir=ltr><FONT face="Times New Roman" color=#000000 size=2>Mr. Friesen:</FONT></DIV>
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<DIV dir=ltr><FONT face="Times New Roman" color=#000000 size=2>Such questions regarding geodetic-accuracy transformations in Colorado are best directed to the U.S. National Geodetic Survey. NADCON indeed does have NAD83 HARNHPGN files, and can provide the necessary operations either on-line or through a download. The same goes for current versions of CorpsCon. Both solutions are not commercial and both are free.</FONT></DIV>
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<DIV dir=ltr><FONT size=2>Go to <A href="http://www.NOAA.NGS.gov">www.NOAA.NGS.gov</A> and you'll get your problem solved for free courtesy of the U.S. Government. A Google search will get you to the current version of CorpsCon.</FONT></DIV>
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<DIV dir=ltr><FONT size=2>C. Mugnier</FONT></DIV>
<DIV dir=ltr><FONT size=2>LSU</FONT></DIV></DIV>
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<FONT face=Tahoma size=2><B>From:</B> proj-bounces@lists.maptools.org on behalf of Aaron Friesen<BR><B>Sent:</B> Thu 19-Feb-09 11:20<BR><B>To:</B> proj@lists.maptools.org<BR><B>Subject:</B> [Proj] How to transform between NAD83 HARN/HPGN and WGS84<BR></FONT><BR></DIV>
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<P><FONT size=2>Everyone,<BR><BR>I checked the archives for the past year and did not find an<BR>answer to this. Google did not provide me with any leads<BR>either.<BR><BR>I have data in NAD83 HARN for Colorado. I need to take the<BR>data into the field as WGS84, update it/add to it, and get<BR>it back as NAD83 HARN for Colorado. The data I am collecting<BR>has sub-foot accuracy, so "close" is not good enough.<BR><BR>The information on the grid files does not address the<BR>HARN/HPGN question.<BR><BR>Is this type of transformation with the accuracy I need<BR>possible with Proj?<BR><BR>Are HARN grid files available or are towgs84 settings defined<BR>for the various HARN areas?<BR><BR>Or am I stuck looking for an alternative, commercial solution?<BR><BR>Thank for your assistance.<BR><BR>Aaron<BR><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>