[Qgis-user] Re: Google Mercator

[Andre Joost]

Am 10.04.12 12:33, schrieb Hannah Pethen:
> I have observed a similar problem with Google mercator and vector
> files. I have a google satellite map, and several point vector files
> all in google mercator transformation, but the relationship between
> the locations on the map and the locations of the points of the
> vector files are not stable. If I open print composer or change the
> zoom I find the points have moved relative to the map, so that my
> points are not longer in the correct places, although I don't know
> whether the points or the map have moved (or both?). The same thing
> happens with vector line files. This happens whether or not I have
> 'on the fly transformation' checked and if I check 'on the fly
> transformation' and then use vector files in another transformation
> (e.g. EPSG4326) the same problem occurs. I wonder if there is an
> issue with the stability of the transformation and if this is
> affecting both my point locations and the polygon areas referred to
> by Nick.
>

You could try using EPSG:3857 instead of EPSG:900913. For some strange 
reasons raster data transformed to EPSG:900913 is located on the map 
different from EPSG:3857 projected rasters. Maybe another 
Qgis-guesses-projection-issue.

Greetings,
Andre Joost