Displaying a DEM with hillshading

There are two methods for visualizing a DEM using hillshading. The simplest and most interactive is to use the Image Analysis window. Here, you can adjust the illumination with the altitude, azimuth, and z-factor through the Option dialog box or by editing the function properties.

Alternatively, you can turn on hillshading in the Layer Properties dialog box by choosing the Stretched renderer and checking Use hillshade effect. Within the Layer Properties dialog box, you can also adjust the z-value to add a vertical exaggeration.

You can change the illumination angle on the Data Frame Properties dialog box. This will be applied to the hillshade setting made in the Layer Properties dialog box but will not change any function properties when using the Hillshade function.

Steps:

1. Click the Add Data button to add a DEM to ArcMap.
2. To view the Image Analysis window, click Windows on the Main menu, then click Image Analysis.
3. Click the raster layer representing the elevation data in the Image Analysis window.
4. Click the Image Analysis Options button , click the Hillshade tab, then adjust the illumination properties to be applied.
5. Change the color ramp to the grayscale color ramp .

   If you do not change the color ramp, the image generated will use the Shaded Relief function and not the Hillshade function.

6. Click the Shaded Relief button in the Processing section of the Image Analysis window.

   This adds a temporary raster dataset layer to the table of contents.

7. If you want to make adjustments to the illumination:
   1. Right-click the raster layer in the table of contents and click Properties.
   2. Click the Functions tab.

      Functions are added within a mosaic dataset and by the temporary raster layers created from the Image Analysis window. They are used to define processing, which is applied on the fly.

   3. Right-click Hillshade Function and click Properties.
   4. Click the Hillshade tab and edit the properties.
   5. Click OK to close the Raster Properties Function dialog box and click OK again to close the Layer Properties dialog box.

Note:

Gamma can be used to help normalize the display and put more emphasis on lower elevations.