Georeference a raster to another raster automatically

The Auto Georeference functionality allows you to automatically georeference your raster dataset to a referenced raster dataset. The automated control points are based on the spectral signatures of different locations across your image, so it is meant for aerial and satellite imagery that are similar in nature. The Auto Georeference function does not work well with scanned maps, historical data, or elevation data.

To use it, you must place the nongeoreferenced raster in the generally correct geographic location along with a referenced raster that is in a known coordinate system. The Prepare group tools, such as Locate , Fit To Display , Move , Rotate , and Rescale can help you place the raster in the approximate geographic location. When you click the Auto Georeference button, the system creates control points from your unreferenced raster to your referenced raster layer. If accurate control points cannot be created, you may need to adjust the source raster to better overlap the referenced raster.

Note:

Saving the ArcGIS Pro project does not save the current state of a georeferencing session. Export your control points before you close the project.

1. In ArcGIS Pro, add the layer residing in map coordinates.

   The layer must be an image of similar geographic location, time and season, orientation, scale, and band combination as the image you are automatically georeferencing.

2. Add the raster dataset you want to georeference.

   Adding the data with the map coordinate system first is a good practice so you do not need to set the map frame coordinate system. It also places the raster you are georeferencing above the reference layers.

3. In the Contents pane, right-click a target layer (the dataset in the correct location) and click Zoom to Layer.
4. In the Contents pane, click the source raster layer you want to georeference.
5. Click the Imagery tab and click Georeference to open the Georeference tab.

   The tools on the Georeference tab are divided into several groups to help you use the correct tools in the different phases of your georeferencing session.

6. In the Prepare group, click Set SRS .

   If your raster dataset already has a spatial reference, it is automatically used as the coordinate system for the map and the georeferencing session. If your raster dataset does not have a spatial reference, the Map Properties dialog box appears, and you can choose the coordinate system for the georeferencing session. The default spatial reference is the current coordinate system of the map.

7. Use the navigation tool to zoom and pan to the location of your source raster.
   1. Optionally, click Locate to zoom in to a city or address.
8. Click Fit To Display .

   The raster layer you are georeferencing is placed with the current map display.

9. Optionally, use Move , Scale , and Rotate to place the raster as needed.
10. In the Contents pane, turn off the visibility of any layer that you do not want to use as a reference dataset. This includes the basemap layer, unless it is the World Imagery layer.
11. In the Adjust group, click the Auto Georeference button .

    The system matches your raster to the reference layers.

12. On the Transforms drop-down menu , choose the transformation you want to use.

    Zero-order polynomial	Minimum of one control point required
    First-order polynomial	Minimum of three control points required
    Adjust	Minimum of three control points required
    Projective transformation	Minimum of four control points required
    Second-order polynomial	Minimum of six control points required
    Third-order polynomial	Minimum of ten control points required
    Spline transformation	Minimum of ten control points required

13. In the Review group, click the Control Point Table button to evaluate the residual error for each control point.

    Press the L key to switch the transparency of your source raster on and off.

14. Delete any unwanted control points using the Control Point table. Alternatively, edit the inaccurate points by selecting them and moving the vertices.
15. Use Add Control Points to manually add control points to an area that needs more control points.
16. When you're satisfied with the current alignment, stop entering control points.
17. In the Save group, choose how you want to save your georeferencing information.

    Save	Save the georeferencing information with the raster and its auxiliary files.
    Save as New	Create a raster file with the georeferencing information.
    Export Control Points	Save the control points in a text file.

You can now use your georeferenced raster dataset in your GIS projects.

For more georeferencing workflows, see Georeference historical imagery in ArcGIS Pro.