[Qgis-user] QGIS/GDAL GML flipped coordinate order with URN/URI srsName

[Even Rouault]

Le mardi 11 octobre 2016 12:21:32, Ilkka Rinne a écrit :
> Ok, thanks for the quick answer and bug fix!
> 
> Any idea about the planned version of QGIS that would include GDAL 2.1.2?

I'm not sure what Jürgen's plans are, but once GDAL 2.1.2 will be released and 
available in OSGeo4W, I think that should probably affect all QGIS versions 
that currently use GDAL 2.1.X ?

> 
> 
> Ilkka
> 
> On Tue, Oct 11, 2016 at 12:59 PM, Even Rouault <even.rouault at spatialys.com>
> 
> wrote:
> > Le mardi 11 octobre 2016 10:47:09, Ilkka Rinne a écrit :
> > > Hi,
> > > 
> > > We are experiencing an unwanted flipping of coordinate order
> > 
> > interpretation
> > 
> > > when adding GML 3.2 files as new vector layers in QGIS 2.2 Valmiera.
> > > 
> > > The GML data is has been encoded as a wfs:featureCollection with EU
> > 
> > INSPIRE
> > 
> > > ProtectedSite 4.0 features as collection members (XML Schema:
> > > http://inspire.ec.europa.eu/schemas/ps/4.0/ProtectedSites.xsd). When
> > 
> > using
> > 
> > > the URI-type srsName "http://www.opengis.net/def/crs/EPSG/0/3035" the
> > > coordinates seem to be interpreted (by GDAL?) in order (easting,
> > 
> > northing),
> > 
> > > while the official axis order (according to the EPSG-registry) is
> > > (northing, easting). If we change the srsName to the URN-type format
> > > "urn:ogc:def:crs:EPSG::3035" in the GML file, the import seems to use
> > > the correct coordinate order.
> > > 
> > > To comply with the INSPIRE requirements, we have to use the URI format
> > > srsNames, but this is likely to cause a lot of confusion for the QGIS &
> > > GDAL users of the data if the coordinates are interpreted in the wrong
> > > order.
> > > 
> > > I'm fully aware of the massively confusing lat/lon (x/y) coordinate
> > > order interpretation misalignment between the geographers and the
> > > (GIS)
> > 
> > software
> > 
> > > implementors, but was not aware that this issues also shows it's ugly
> > 
> > head
> > 
> > > for other CRSes than CRS 84/EPSG:4326.
> > 
> > It's a mess indeed, reinforced by constant changes in srsName syntaxes.
> > 
> > > Question 1: Is this an intentional feature or a bug?
> > 
> > This was a bug. I've just fixed it per https://trac.osgeo.org/gdal/
> > ticket/6678
> > (in time for the upcoming GDAL 2.1.2)
> > 
> > > Question 2: Is it possible to force GDAL from the QGIS UI to interpret
> > 
> > the
> > 
> > > coordinate order of these GML files in the official order?
> > 
> > No workaround I can think of, apart the manual replacing as you did.
> > 
> > Even
> > 
> > --
> > Spatialys - Geospatial professional services
> > http://www.spatialys.com

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