[mapserver-users] Projection error, RT90 in MapServer

[Fia]

Hello,

I have a problem showing data in the former Swedish standard reference
system RT90 2,5 gon V. The point is projected ~250 meters northwest of where
it should be. I have used the projection parameters for MapServer from
Spatialreference.org.

The underlying map projection is SWEREF 99 TM (the new standard Swedish
reference system), with the following projection parameters:
PROJECTION
	'proj=utm'
	'zone=33'
	'ellps=GRS80'
	'towgs84=0,0,0,0,0,0,0'
	'units=m'
	'no_defs'
END

I have then tested to pinpoint an intersection, in both WGS-84 and RT90, but
the RT90 point does not end up where it should be.  I have double checked
that the RT90 coordinates are correct by transforming them to WGS-84. See my
attached screenshot.
http://n2.nabble.com/file/n4438959/rt90_mapserver_error.jpg 

For the WGS-84 point I have the following projection parameters:
PROJECTION
	'proj=longlat'
	'ellps=WGS84'
	'datum=WGS84'
	'no_defs'
	'units=m'
END

And the RT90 point has:
PROJECTION
	"proj=tmerc"
	"lat_0=0"
	"lon_0=15.80827777777778"
	"k=1"
	"x_0=1500000"
	"y_0=0"
	"ellps=bessel"
	"units=m"
	"no_defs"
END

I have also tried all the other RT90 projections provided by
Spatialreference.org, just to see if any of them would work better, but
without luck.

Have I made a mistake somewhere, or are there any suggestions of why this
error occurs? I'm out of ideas. 

Regards,
Sofia
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