[Gdal-dev] Reproject with Mapserver vs gdalwarp

[José Vicente Higón]

Hi,
I configured a layer in Mapserver which datasource was an ECW image in 
EPSG:23030. When I requested the layer in other reference system like 
EPSG:4326, I got an error, the image was shift some meters. We solve the 
problem modifying the epsg file in proj directory with this line:
<23030> +proj=utm +zone=30 +ellps=intl +towgs84=-87,-98,-121,0,0,0,0 +units=m 
+nadgrids=sped2et.gsb +no_defs  <>
and adding the file sped2et.gsb in the same location as the epsg file. With 
these changes Mapserver worked fine and the error disappeared. 
My surprise was when I tried to reproject a raster with gdalwarp:
gdalwarp -of HFA -s_srs "EPSG:23030" -t_srs "EPSG:4326" source.ecw dest.img
I got the image with the shift error, in fact, I got the same image before 
made the changes in the proj file. 

In both cases I was using the latest FWTools release (1.3.4)

Why Did I get differents results in MApserver and gdalwarp?Any clue?

Thanks in advance

-- 
José Vicente Higón Valero
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