QGIS can re-project a layer using both on-the-fly re-projection for the current session; and by saving a copy of the layer with a new Co-ordinate Reference System (CRS) defined.
On the fly
This is useful when a layer only needs to be re-projected for the current session.
Add the layer. If the CRS is known, QGIS will re-project it if necessary.
To check which CRS has been specified for the layer, right click on the layer in the Layers Panel, select Properties, and then select the General tab.
To save a new copy
It is a good practice to save a copy of a layer once it has been re-projected. This is to ensure the new CRS and transformations are permanently assigned to it. This avoids transformation errors when it is added to later map documents.
To save a copy:-
- Right click on the layer in the Layers Panel , select Save As.
- In the Save Vector layer as dialog, specify the filename, plus the new Co-ordinate Reference System. It is possible to add a symbology reference scale and new attributes. It is a good idea to add the new layer to the map to check it is correctly projected.