If the map layer you wish to configure is an ArcInfo® DEM (.asc), ASCII DEM (.dem), or ASCII NetTIN (.net) file, selecting *Properties from the map opens the Elevation Options editor ("Figure: Elevation Options Editor"). The Elevation Options editor is organized in two tabs—Properties and Scale.

Figure: Elevation Options Editor

The Properties tab allows you to define the properties for drawing the terrain map using color contours. The drawing properties include:

  • The Color Contour type—this is the selector in the upper left corner of the panel. The selection list includes: Aspect Shading, Grayscale, Linear, Precipitation, Red-Green-Blue, or Terrain.
  • Draw Edges—this option is specifically for ASCII NetTIN files. If checked, the edges of the triangles that make up an ASCII NetTIN file will be drawn.
  • Tic Interval—used for marking the color contours
  • Contour Limits—set the Maximum/Minimum values for Contour Limits. By default, Contour Limits are set to System Specified Min/Max Values based on the elevation data in stored in the map. If you deselect the checkbox, you can enter custom values.
  • Brightness—the relative lightness or darkness of a color from 0 to 1 (black to white).
  • Saturation—the intensity or density of the color, measured from 0 (grey) to 100 (vivid color).
  • Transparency—the level of opacity, measured from 0.0 to 1.0, of your gridded data layer.
  • Aspect Shading—On/Off—If you are using elevation maps, you may wish to choose Aspect Shading as the color contour and activate the Aspect Shading option. Aspect Shading uses a single color and makes the map appear in relief by placing an imaginary light source above the map and shading the elevation contours. When the Aspect Shading option is On, use the Angle slider to adjust the angle of the light source.
  • Maximum Clipping and Minimum Clipping—On/Off—by default, these options are unchecked (Off). If you activate these options, the Value sliders and Color buttons become available for setting the end points of the color ramp.
    • The Value sliders allow you to specify the amount of Clipping within the Contour Limits you have specified; you can also type values into the text boxes.
    • Color—these buttons open the Color Chooser (see "Using the Color Chooser" for a description of the Color Chooser).
  • Scale—The color ramp on the right side of the Properties tab will reflect your drawing property settings.

On the Scale tab of the Elevation Options Editor ("Figure: Elevation Options - Scale Tab"), you can specify how the map will be displayed based on zoom level:

Figure: Elevation Options - Scale Tab


  • Always show layer—by default, the digital line graph layer is set to always display, regardless of the zoom level.
  • Only show layer in the following scale range—select this radio button if you want the map to display only for specific zoom ranges:
    • Only visible below 1: To set the scale (zoom range) so that the digital line graph layer becomes visible as you zoom-in, you can set the scale to the current scale by clicking Set to Current or enter a value in the box.
    • Only visible above 1: To set the scale so that the digital line graph layer becomes visible as you zoom-out, you can set the scale to the current scale by clicking Set to Current or enter a value in the box.