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i'm having an issue with QGIS 2.14.3 (Windows 10). I've two layers:

  • PostGIS table (EPSG:23030)
  • Shapefile (EPSG:25830)

I setup on the fly transformation (23030) in QGIS, just for check, but both layers does not overlay.

However if I do same thing with another software (gvSIG or ArcGIS) it works fine.

Anyone knows what is happening?

  • 2
    if the layers dont overlay, their CRS is not set correctly. Do you have a third layer to test, which of both is incorrect? – Revo May 30 '16 at 13:20
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thanks for your answers.

I think the problem is the +towgs84 parameter. The 23030 layer is stored in a PostGIS 1.4.2 database and it hasn't +towgs84 in proj4text column spatial_ref_sys table:

+proj=utm +zone=30 +ellps=intl +units=m +no_defs

Could be this the problem?

Greetings.

  • Yes, this is wrong. QGIS has +proj=utm +zone=30 +ellps=intl +towgs84=-87,-98,-121,0,0,0,0 +units=m +no_defsfor EPSG:23030. – AndreJ Jun 1 '16 at 12:11
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How big is the shift? If it is around 100m it might be due to datum transformation as another reference ellipsoid is used in both. If this is the case you need the transformation parameters for ED 50 towards GRS80 in Qgis. The other programs might have this already and applying it therefore correctly.

You can also reproject on of them using the also installed grass-gis with v.proj as grass gis tend to have more transformations already delivered.

  • The shift is arround just 20m. It is very odd. Usually the shift betwen this srs is about 200m... I'll try to reproject with grass to check. Thanks Matte. – Viskovitz May 31 '16 at 20:13

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