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<DIV dir=ltr align=left><SPAN class=874183114-11012006><FONT face=Arial
color=#0000ff size=2>FP -</FONT></SPAN></DIV>
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<DIV dir=ltr align=left><SPAN class=874183114-11012006><FONT face=Arial
color=#0000ff size=2>Your first GPS layer definition should be fine. You
don't say what data source you are using for your GPS data, but if it is a
shapefile or inline features you will be using decimal degrees and those will
work fine with the "init=epsg:4326" definition.</FONT></SPAN></DIV>
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<DIV dir=ltr align=left><SPAN class=874183114-11012006><FONT face=Arial
color=#0000ff size=2>The first thing I would suggest is that you confirm that
the EPSG:27582 projection is in fact correct. The related Paris / Lambert
projections (27581-27584, for example) are all rather similar and can certainly
look the same. Can you check the coordinates of a few points to make sure
they're accurate? An error of 200km is far too large to be a datum error,
but could easily be due to the different false easting/northing values used in
these similar projections.</FONT></SPAN></DIV>
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<DIV dir=ltr align=left><SPAN class=874183114-11012006><FONT face=Arial
color=#0000ff size=2> - Ed</FONT></SPAN></DIV>
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<DIV dir=ltr align=left><SPAN class=874183114-11012006><FONT face=Arial
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<P><FONT size=2>Ed McNierney<BR>President and Chief Mapmaker<BR>TopoZone.com /
Maps a la carte, Inc.<BR>73 Princeton Street, Suite 305<BR>North Chelmsford,
MA 01863<BR>ed@topozone.com<BR>(978) 251-4242
</FONT></P></FONT></SPAN></DIV><BR>
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<FONT face=Tahoma size=2><B>From:</B> UMN MapServer Users List
[mailto:MAPSERVER-USERS@LISTS.UMN.EDU] <B>On Behalf Of </B>zze-SIGALE PORTANERI
F ext RD-BIZZ-SOP<BR><B>Sent:</B> Wednesday, January 11, 2006 7:20
AM<BR><B>To:</B> MAPSERVER-USERS@LISTS.UMN.EDU<BR><B>Subject:</B>
[UMN_MAPSERVER-USERS] Projection WGS84 in decimal degree<BR></FONT><BR></DIV>
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<P><FONT face=Arial size=2>Hi all,</FONT> </P>
<P><FONT face=Arial size=2>I have a set of WGS84 data points that come from GPS
system in decimal degree</FONT> <FONT face=Arial size=2>longitude/latitude
coordinates.</FONT> <BR><FONT face=Arial size=2>I would like to display them
with mapserver using a mapfile which already define several layers in Lambert
II.</FONT> </P>
<P><FONT face=Arial size=2>I did specified the global projection in the mapfile
for Lambert II etendu :</FONT> </P>
<P><FONT face="Courier New" size=2>PROJECTION</FONT><BR><FONT face="Courier New"
size=2>"init=epsg:27582"</FONT><BR><FONT face="Courier New"
size=2>END</FONT><BR><BR><FONT face=Arial size=2>The GPS LAYER describing the
WGS84 data includes the projection definition for the WGS84 :</FONT> <BR><FONT
face="Courier New" size=2>LAYER<BR> NAME "GPS"<BR>
PROJECTION<BR> "init=epsg:4326"<BR> END<BR>
...<BR>END</FONT> <BR><FONT face=Arial size=2>But points are not displayed at
the right place (at about 200km far away) :-( </FONT><BR><FONT face=Arial
size=2>Apparently, the 4326 epsg definition considers longitude/latitude
coordinates in Degree/Minute/Second, while my data are in Decimal
Degrees.</FONT><BR><BR><FONT face=Arial size=2>So I tried to specify the
following in the GPS layer :<BR></FONT><BR><FONT face="Courier New"
size=2>PROJECTION</FONT><BR><FONT face="Courier New"
size=2>"proj=longlat"</FONT><BR><FONT face="Courier New"
size=2>"ellps=WGS84"</FONT><BR><FONT face="Courier New"
size=2>"datum=WGS84"</FONT><BR><FONT face="Courier New"
size=2>"units=dd"</FONT><BR><FONT face="Courier New"
size=2>END</FONT><BR><BR><BR><FONT face=Arial size=2>but mapserver returns:
"Error in msProcessProjection(): unknown unit conversion id" </FONT><BR><FONT
face=Arial size=2>The prog -lu command doesn't list the "dd" unit...</FONT>
<BR><FONT face=Arial size=2>How to display longlat data in Decimal Degree under
Mapserver?<BR></FONT><BR><FONT face=Arial size=2>Regards</FONT> <BR><FONT
face=Arial size=2>FP</FONT> </P></BODY></HTML>