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Working with CRS
When working with spatial data, it is important that a CRS is assigned to the data and the QGIS project. To view the CRS for the QGIS project, click on Properties under Project, and choose the CRS tab.
It is recommended that all data added to a QGIS project be projected into the same CRS as the QGIS project. However, if this is not possible or convenient, QGIS can project layers on the fly to the project's CRS.
If you want to quickly search for a CRS, you can enter the EPSG code to quickly filter through the CRS list. An EPSG code refers to a specific CRS stored in the EPSG Geodetic Parameter Dataset online registry that contains numerous global, regional, and local CRSs. An example of a commonly used EPSG code is 4326, which refers to WGS 84. The EPSG online registry is available at http://www.epsg-registry.org/.
To view the CRS for a layer, perform the following steps:
- Open the layer's properties by either navigating to Layer | Properties, or by right-clicking on the layer in the Layers panel
- Choose Source from the context menu
- If the layer's CRS is not set or is incorrect, click on the globe at the end of the drop-down menu, and select the correct CRS