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<DIV><FONT face=Arial size=2><SPAN class=767593321-25112002>Grass
5.0.0</SPAN></FONT></DIV>
<DIV><FONT face=Arial size=2><SPAN
class=767593321-25112002>spar-sun-solaris2.7</SPAN></FONT></DIV>
<DIV><FONT face=Arial size=2><SPAN
class=767593321-25112002></SPAN></FONT> </DIV>
<DIV><FONT face=Arial size=2><SPAN class=767593321-25112002>I am having trouble
projecting vector data to a new projection/datum.</SPAN></FONT></DIV>
<DIV><FONT face=Arial size=2><SPAN class=767593321-25112002>I have North
Carolina state plane (NCSP) NAD83 Meters raster aerial photo
data.</SPAN></FONT></DIV>
<DIV><FONT face=Arial size=2><SPAN class=767593321-25112002>I have NCSP NAD83
Feet road data. I v.proj the road data and it appears
fine.</SPAN></FONT></DIV>
<DIV><FONT face=Arial size=2><SPAN class=767593321-25112002>(The roads overlay
the roads on the raster.)</SPAN></FONT></DIV>
<DIV><FONT face=Arial size=2><SPAN
class=767593321-25112002></SPAN></FONT> </DIV>
<DIV><FONT face=Arial size=2><SPAN class=767593321-25112002>I have NCSP NAD27
feet data of Cadastral (Property). When I v.proj this data
to </SPAN></FONT></DIV>
<DIV><FONT face=Arial size=2><SPAN class=767593321-25112002>NCSP NAD83 Meters,
it appears about 9700 Meters west of the NAD83 data (using</SPAN></FONT></DIV>
<DIV><FONT face=Arial size=2><SPAN class=767593321-25112002>d.measure).
When I v.proj UTM zone 18 NAD27 Meters Hydrography data, it
appears</SPAN></FONT></DIV>
<DIV><FONT face=Arial size=2><SPAN class=767593321-25112002>at the same relative
position as the other NAD27 data (the Cadastral data).</SPAN></FONT></DIV>
<DIV><FONT face=Arial size=2><SPAN
class=767593321-25112002></SPAN></FONT> </DIV>
<DIV><FONT face=Arial size=2><SPAN class=767593321-25112002>In other words, the
NAD83 data lines up. The NAD27 data lines up with NAD27
data.</SPAN></FONT></DIV>
<DIV><FONT face=Arial size=2><SPAN class=767593321-25112002>But NAD27 does not
line up with NAD 83.</SPAN></FONT></DIV>
<DIV><FONT face=Arial size=2><SPAN
class=767593321-25112002></SPAN></FONT> </DIV>
<DIV><FONT face=Arial size=2><SPAN class=767593321-25112002>It looks like the
projection is occurring correctly but the datum transformation is
not.</SPAN></FONT></DIV>
<DIV><FONT face=Arial size=2><SPAN
class=767593321-25112002></SPAN></FONT> </DIV>
<DIV><FONT face=Arial size=2><SPAN class=767593321-25112002>I have carefully set
up the proj_info and proj_units files. I even copied over Eric
Miller's</SPAN></FONT></DIV>
<DIV><FONT face=Arial size=2><SPAN class=767593321-25112002>state plane files
and tried those. Same results. (see <A
href="http://pweb.jps.net/~egm2/grass/STP/index.html">http://pweb.jps.net/~egm2/grass/STP/index.html</A>)</SPAN></FONT></DIV>
<DIV><FONT face=Arial size=2><SPAN
class=767593321-25112002></SPAN></FONT> </DIV>
<DIV><FONT face=Arial size=2><SPAN class=767593321-25112002>The difference is
suspiciously similar to the difference in false easting between NCSP NAD83 and
</SPAN></FONT></DIV>
<DIV><FONT face=Arial size=2><SPAN class=767593321-25112002>NCSP NAD27.
</SPAN></FONT></DIV>
<DIV><FONT face=Arial size=2><SPAN
class=767593321-25112002></SPAN></FONT> </DIV>
<DIV><FONT face=Arial size=2><SPAN class=767593321-25112002>Projecting from the
NAD83 M to NAD27 Ft (the reverse of above) gives similar
results</SPAN></FONT></DIV>
<DIV><FONT face=Arial size=2><SPAN class=767593321-25112002>with the NAD83 data
appearing 9700 meters east of the NAD27 data</SPAN></FONT></DIV>
<DIV><FONT face=Arial size=2><SPAN
class=767593321-25112002></SPAN></FONT> </DIV>
<DIV><FONT face=Arial size=2><SPAN class=767593321-25112002>Am I doing something
wrong? Has anyone else had a similar problem?</SPAN></FONT></DIV>
<DIV><FONT face=Arial size=2><SPAN
class=767593321-25112002></SPAN></FONT> </DIV>
<DIV><FONT face=Arial size=2><SPAN class=767593321-25112002>John
Gillette</SPAN></FONT></DIV>
<DIV><FONT face=Arial size=2><SPAN
class=767593321-25112002></SPAN></FONT> </DIV>
<DIV><FONT face=Arial size=2><SPAN
class=767593321-25112002></SPAN></FONT> </DIV></BODY></HTML>