Solve common projection issues

Projections are calculations that allow you to draw the round earth on a flat screen or piece of paper. To function in a GIS, every layer needs to be defined within a coordinate system, which allows it to be projected onto the map. Issues with the projection can cause data to not appear correctly or at all.

In this tutorial, you'll identify and fix the following three common projection issues:

• A layer with no defined projection, causing it to appear in the wrong place
• A layer with a projection that is different than the one used in the project
• A layer that is misaligned with the other map layers

You'll primarily work with raster data, although the issues and their solutions also apply to other types of data, such as feature classes. To learn how to resolve projection issues for a feature class, try the Fix data when it appears in the wrong place tutorial.

This tutorial was last tested on April 16, 2026, using ArcGIS Pro 3.6. If you're using a different version of ArcGIS Pro, you may encounter different functionality and results.

Requirements

• ArcGIS Pro (see options for software access)

Solve common projection issues

Set a missing spatial reference

For the first projection issue, you'll work with a raster image of a scanned historical map. Its spatial reference is unknown, causing it to not appear in the correct place on the map. Rasters usually have several auxiliary files. One of these files contains spatial reference information, which includes the coordinate system used to project the layer as well as other information about how to display the data on a flat map. If this file is lost or erased, the information is gone.

First, you'll download the data for the tutorial. Then, you'll inspect the image properties.

1. Download the Hallstatt_Projections project package.
2. Browse to the downloaded file and double-click it to open the project in ArcGIS Pro. If necessary, sign in using your licensed ArcGIS account.

   Note:

   If you don't have access to ArcGIS Pro or an ArcGIS organizational account, see options for software access.

   The project contains a map of the world. You'll add the raster image to it from the Catalog pane.

3. In the Catalog pane, expand Folders, Hallstatt_Projections, commondata, and userdata.

   Note:

   If you don't see the Catalog pane, on the ribbon, click the View tab. In the Windows group, click Catalog Pane.

   

   The userdata folder contains the raster data you'll work with in this tutorial.

4. Right-click Hallstatt_HistoricDrawing.JP2 and choose Properties.
5. In the Raster Dataset Properties window, collapse the Data Source and Raster Information sections. Expand the Spatial Reference section.

   

   The spatial reference is Unknown. You'll need to specify one.

6. Expand the Extent section.

   

   The extent values are not zero or near zero, meaning the raster has an extent. Having an extent suggests that the raster has been properly georeferenced. It has all the information needed to locate it properly on a map except the coordinate system.

   Note:

   If the extent values were zero or near zero, you would probably need to georeference the image before you could display it on the map. To learn how to georeference an image, try the Georeference historical imagery in ArcGIS Pro tutorial.

7. Close the Raster Dataset Properties window.

   Next, you'll display the image on the map.

8. In the Catalog pane, right-click Hallstatt_HistoricDrawing.JP2 and choose Add To Current Map.

   Note:

   If the Calculate statistics window appears asking whether you want to calculate statistics for one of these rasters, click Yes. Statistics are needed to properly symbolize and render raster data.

   A warning appears, informing you that the layer has an unknown coordinate system.

   

   The layer also doesn't seem to appear on the map.

9. In the Contents pane, right-click Hallstatt_HistoricDrawing.JP2 and choose Zoom To Layer.

   

   The map zooms to the image, which shows a historic map of Hallstatt, Austria. From external documentation about the map, you determine it is using the MGI Austria GK Central coordinate system, which is designed for displaying Austrian data. Based on the basemap, however, the image appears to be located in the ocean.

10. On the map, zoom out until you can see where the imagery is located.

    The image is off the coast of Africa, not in Austria.

    

    Next, you'll define the projection as MGI Austria GK Central using the Define Projection tool.

11. On the ribbon, click Analysis. In the Geoprocessing group, click Tools.

    

    The Geoprocessing pane appears.

12. In the Geoprocessing pane, search for Define Projection. In the list of results, click the Define Projection tool.

    

13. For Input Dataset or Feature Class, choose Hallstatt_HistoricDrawing.JP2.
14. For Coordinate System, click the Select coordinate system button.

    

15. In the Coordinate System window, in the search box, type MGI Austria GK Central and press Enter.

    The coordinate system is chosen.

    

    Note:

    If the correct coordinate system is not chosen automatically, expand Projected Coordinate System, National Grids, and Austria. Click MGI Austria GK Central to choose it.

16. Click OK.
17. In the Geoprocessing pane, confirm Coordinate System is set to MGI_Austria_GK_Central. Click Run.

    The tool runs and the projection is defined for the dataset.

18. In the Contents pane, right-click Hallstatt_HistoricDrawing.JP2 and choose Zoom To Layer.

    On the map, the Hallstatt_HistoricDrawing.JP2 layer now properly appears in the Hallstatt, Austria, area.

    

Reproject a dataset

For the second projection issue, a digital surface model (DSM) has valid spatial reference information, but the coordinate system it uses does not match the one chosen for the project.

1. In the Contents pane, turn off Hallstatt_HistoricDrawing.JP2.
2. At the bottom of the Geoprocessing pane, click the Catalog tab.

   

3. In the userdata folder, right-click DSM.tif and choose Properties.

   The Spatial Reference section shows the projected coordinate system used by the dataset.

   

   The coordinate system is set as MGI_Austria_Lambert. This spatial reference is valid, but you're using MGI_Austria_GK_Central for this project. You'll reproject the raster to the correct coordinate system using the Project Raster tool.

4. Close the Raster Dataset Properties window. At the bottom of the Catalog pane, click the Geoprocessing tab.
5. In the Geoprocessing pane, click the Back button.

   

6. Search for Project Raster. In the list of results, click Project Raster.

   This tool reprojects a raster dataset from one coordinate system to another. You'll reproject the DSM to MGI Austria GK Central.

7. For Input Raster, click the Browse button.

   

8. In the Input Raster window, expand Folders, Hallstatt_Projections, commondata. Click userdata.

   

9. Click DSM.tif to select it and click OK.

   The DSM is added as the input raster.

10. In the Geoprocessing pane, for Output Raster Dataset, click the Browse button.
11. In the Output Raster Dataset window, expand Folders and click Hallstatt_Projections. For Name, type Hallstatt_DSM.tif.

    

12. Click OK.

    Next, you'll set the coordinate system. Rather than searching for it, you can choose the same coordinate system as the historic image.

13. For Output Coordinate System, choose Hallstatt_HistoricDrawing.jp2.

    The parameter automatically changes to the coordinate system of the layer you chose, MGI_Austria_GK_Central. Lastly, you'll change the resampling technique to bilinear interpolation, which is better for elevation data such as a DSM.

14. For Resampling Technique, choose Bilinear interpolation.

    

15. Click Run.

    The tool runs. The reprojected DSM is added to the map. It appears in the correct place, near Hallstatt.

    

16. Close the Geoprocessing pane.

Fix a misalignment

For the third projection issue, you'll resolve a misalignment between an image layer and the basemap. You'll resolve this issue in a different map than the one you've been working with so far.

1. Above the map, click the Projection Map 2 tab.

   

   This map contains no data except the basemap. You'll add the misaligned image to it.

2. In the Catalog pane, expand commondata and userdata.
3. Right-click Hallstatt_Image.tif and choose Add To Current Map.

   The image does not line up correctly with the basemap.

   

   You'll inspect the image properties to identify the issue.

4. In the Contents pane, double-click Hallstatt_Image.tif.

   

   The Layer Properties window appears.

5. In the Layer Properties window, click the Source tab.
6. Expand Spatial Reference.

   

   The spatial reference is set to MGI Austria GK Central. This coordinate system is correct for this region, so the image must be misaligned for a different reason.

7. Close the Layer Properties window.
8. In the Contents pane, double-click Projection Map 2.

   

9. In the Map Properties window, click the Coordinate Systems tab.

   

   The map also uses the MGI Austria GK Central coordinate system, the same as Hallstatt_Image.tif. For maps, the default coordinate system is WGS 1984 Web Mercator (auxiliary sphere). However, when you first add a layer to a map, the map's coordinate system is updated to match the layer's, which is why the map and the layer have the same coordinate system.

   You have not yet found the problem. Next, you'll inspect the transformation information.

10. Click the Transformation tab.

    

    To convert between the map's default coordinate system, WGS 1984 Web Mercator (auxiliary sphere), and the image's, MGI Austria GK Central, a transformation called a geographic datum transformation is needed. By default, the transformation is set to the default value, MGI To WGS 1984. However, this transformation is not correct for this region. In this case, the correct transformation is MGI To WGS 1984 3.

    Note:

    Usually, ArcGIS Pro chooses the correct geographic transformation, but not always. To find the appropriate transformation, refer to Geographic and Vertical Transformation Tables. On page 44, there are several versions of MGI_To_WGS_1984. The Area of Use section indicates two appropriate transformations for Austria: MGI_To_WGS_1984_2 and MGI_To_WGS_1984_3.

11. Click MGI To WGS 1984 and choose MGI To WGS 1984 3.

    

12. Click OK.

    The map updates. You'll make the image transparent to compare it to the basemap.

13. In the Contents pane, click Hallstatt_Image.tif to select it.
14. On the ribbon, click the Raster Layer tab. In the Effects group, for Transparency, type 60.0%.

    

    The image becomes transparent. It now aligns correctly with the basemap.

    

15. On the Quick Access Toolbar, click the Save Project button.

    

In this tutorial, you learned how to solve three types of spatial reference issues using raster data. First, you set a spatial reference for a dataset that was missing one. Then, you reprojected data to match the projection used in the project. Lastly, you performed a transformation to fix a misalignment.

To learn more about projections, try the Choose the right projection tutorial. For more tutorials about working with imagery layers, try the Prepare imagery and raster data for analysis series.

You can find more tutorials in the tutorial gallery.

Acknowledgements

• Hallstatt data and imagery: State of Upper Austria
• World Topographic Map sources: Esri, TomTom, Garmin, FAO, NOAA, USGS, OpenStreetMap contributors, and the GIS User Community
• World Hillshade layer sources: Esri, Vantor, Airbus DS, USGS, NGA, NASA, CGIAR, N Robinson, NCEAS, NLS, OS, NMA, Geodatastyrelsen, Rijkswaterstaat, GSA, Geoland, FEMA, Intermap, and the GIS user community