[Qgis-user] Vectors data and raster with same projection didnot overlap

[Andre Joost]

Am 23.10.2014 um 08:51 schrieb Nadarajah Thirugnanasothy:
> I was trying to help someone and had similar problem with two sets of
> vector data. Tried all these methods and failed.When I searched the
> net to find an answer, I found many people have similar problem.What
> about some one actually showing how to do this with a data set and
> posting it as a tutorial (with screen shots) some where. I do not
> have the data set that I was playing with. Thank youThiru(I am 70
> years old & retired now. Had used ESRI/ArcView & Arc Info about 10
> years ago )
>

Unfortuantely, there is no easy way to discover the reasons for not 
overlapping.

If it is about 100m, this is most likely a datum shift issue.

Google/Web Mercator datasources may shft to about 20km vertically if the 
transformation method is wrongly implemented (like EPSG:3395).

If the images are totally off, most probably projection definitions have 
been simply exchanged instead of doing a correct coordinate 
reprojection. Comparing the layer extent is the best to sort this out.

HTH,
André Joost