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I have a shapefile of building lots in Manaus, Brazil, that I have re-projected into the WGS84 (EPSG:4326) CRS using the "project" tool in ArcGIS. I am now working in QGIS, and am trying to add the Google Maps XYZ Tile to this layer. However, it appears that these two layers are not projecting properly:

layer mismatch

How can I transform the CRS to make the projections match?

My friend was able to fix the problem in ArcGIS by changing the properties of the data frame - is there an analogous operation in QGIS?

  • Changing the project CRS (Project > Properties > CRS) solve the projection issue? – Gabriel De Luca Feb 6 at 14:36
  • If I open QGIS, add the Google Map layer to the canvas, change the project properties to EPSG: 4326, and add in the building lot layer that is already in that CRS, I still have the same projection error as before. – Obie K Feb 6 at 14:43
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    If you, after that, change the project CRS to EPSG:3857, solve the projection issue? – Gabriel De Luca Feb 6 at 14:44
  • Unfortunately not. My steps were: open QGIS -> Open Google Map XYZ tile -> change project CRS to EPSG:4326 -> open building lot layer (which is in WGS84) -> change project CRS to EPSG:3857 but to no avail – Obie K Feb 6 at 14:54
  • Instead of using Google Maps use OpenStreetMap and see if you have the same error. – GreyHippo Feb 6 at 16:46
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Seems to be a problem with the CRS of the shapefile layer.

In QGIS, it can be changed in Layer > Properties > CRS.

Changing the CRS of the layer doesn't modify the coordinates of its geometries, but the way they should be interpreted.

When you find and assign the correct CRS in which the coordinates of the geometries must be interpreted (always rendering the canvas, that is, establishing for the project, to EPSG: 3857 due to the base map), you can reproject the layer to another CRS if you want it.

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I would refer you to “Chapter 5 of Learning Geospatial Analysis with Python (Joel Lawhead)”. It's an error of a global projection system. Remember that because of the geoid, no measurement could be correct. Especially, when it wants to map the world using a single datum or ellipsoid.

It's not a problem with CRS or something. Google Earth or any other service that uses any kind of global projection system has up to 15 meters of error. I think that your shapefile had been created by the survey specialists in a local coordinate system before they converted it into something more conventional.

You have to move the entire shapefile regarding a reference point on the online map service. But remember that your correct coordinates will be falsified.

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