3

I am trying to import points from a shapefile in QGIS. First, I select the correct coordinate reference system (NAD83 / MTM zone 11) when importing the file, and it imports correctly. I even checked the coordinates of a known point, and it matches. However, when I add a map from Google Maps (XYZ Tiles) in the background, all the points are around 20 km off from where they are supposed to be.

From what I understand, it seems that there is a problem when QGIS converts between the different CRS. However, from what I read, it seems that QGIS should do the conversions on the fly and automatically. What should I do to fix this?

If it is any uses, my project CRS is NAD83 / MTM zone 11 (the same as my data), and my QGIS version is 3.2.0

  • 3
    QGIS can't reproject 'on the fly' Google Maps tiles, they are served in EPSG:3857. If you want them as a web tiles layer, and see your other layers matching with them, you need to use web mercator for your project CRS. – Gabriel De Luca Feb 7 at 22:57
  • Thanks for the reply @GabrielDeLuca. Weirdly, even changing the project CRS to EPSG:3857 or web mercator (EPSG:102113) doesn't fix the problem. In fact, the points don't seem to have moved at all relative to the map. – jonapap Feb 8 at 15:30
  • It is strange that you don't see a relative movement when changing the coordinates of the project, because as far as I know it is not possible to reproject the tiles on the fly. What is the URL that your base map serves? – Gabriel De Luca Feb 8 at 17:32
  • @GabrielDeLuca QGIS 3.4 is entirely capable of reprojecting Google Maps tiles on the fly. I currently have a project with a Google satellite basemap in EPSG:3734. But I think I remember an old version of QGIS (at least older than 2.18) that wasn't able to reproject some basemaps. Or maybe that was back when I still used the OpenLayers plugin, before I switched to QuickMapServices. – csk Feb 8 at 18:06
  • What method did you use to check the coordinates of the known point? – csk Feb 8 at 18:08

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Browse other questions tagged or ask your own question.