[mapserver-users] Mapserver WMS seem not to read +towgs84 parameters

[Rahkonen Jukka]

Hi,
 
I am using  Mapserver version 5.2.0 from MS4W delivery through WMS
1.1.1.  and I was now trying to add the missing +towgs84 parameters for
the Finnish epsg:2393 projection.  I located the epsg file from
MS4W\proj\nad directory and edited it from this:
# KKJ / Finland Uniform Coordinate System
<2393> +proj=tmerc +lat_0=0 +lon_0=27 +k=1 +x_0=3500000 +y_0=0
+ellps=intl +units=m +no_defs  <>
 
to this:
# KKJ / Finland Uniform Coordinate System
<2393> +proj=tmerc +lat_0=0 +lon_0=27 +k=1 +x_0=3500000 +y_0=0
+ellps=intl
+towgs84=-96.0617,-82.4278,-121.743,4.80107,0.34543,-1.37646,1.4964
+units=m +no_defs  <>
 
However, adding +towgs84 parameters do not have any effect on the
Mapserver output.  I am sure that this certain epsg file is read,
because commenting out the <2393> line makes Mapserver to stop working
with my mapfile.  In addition, I can make map to shift by editing +x_0
and +y_0 parameters.  I had even another try by skipping the whole epsg
file by giving the projection directly in the layer definitions of my
mapfile as 
 PROJECTION
      "proj=tmerc"
      "lat_0=0"
      "lon_0=27"
      "k=1"
      "x_0=3500000"
      "y_0=0"
      "ellps=intl"
 
"towgs84=-96.0617,-82.4278,-121.743,4.80107,0.34543,-1.37646,1.4964"
      "units=m"
      "no_defs"
    END
 
Here I can see exactly the same behaviour.  Editing other parameters,
like lon_0, x_0 and y_0 are really changing the output, while editing
towgs84 parameters or leaving them out totally has no effect.  It looks
to me that towgs84 parameters are not read at all, or all the parameters
are interpreted as zeros.  However, I can't believe that this error
wouldn't have been noticed by others so far.  So I am just giving the
parameters in a wrong way?
 
The ESRI projection file at MS4W\proj\nad\ doest have <2393> definitions
with a bit different towgs84 values.  Giving my  layer definition as
"init=esri:2393" does not change anything, Mapserver does not use
towgs84 parameters.
 
-Jukka Rahkonen-
-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://lists.osgeo.org/pipermail/mapserver-users/attachments/20090303/a773465f/attachment.html