Raster Options

Importing Rasters

Import a raster file by selecting Open in the File menu. Select the proper raster file as shown in the following table. Select Open. At the popup "Load it as...", select DEM.

Format	File to Open	Source	Importance	Level of Support
ArcInfo Binary Grid	w001001.adf	ESRI	1	Supported in gms and in sms
ArcInfo Ascii Grid	asc	ESRI	2	Supported in gms and in sms
USGS DEM Grid Float	flt	http://seamless.usgs.gov	2	Supported in gms and in sms
USGS NED Grid Float	*.flt	http://seamless.usgs.gov	2	Supported in gms and in sms
Canadian DEM	*.dem	http://www.geobase.ca	3	Supported in gms and supported in sms
DTED	*.dt0	ERDC	3	Supported in gms and supported in sms
Aster DEM	*.tif	http://asterweb.jpl.nasa.gov/gdem-wist.asp	4	Supported in gms and supported in sms as images
SDTS	*.ddf	http://data.geocomm.com/dem/demdownload.html	5	Supported in gms and supported in sms

Displaying Rasters

The raster display options are accessed by clicking on the Raster Options item or tab in the Display Options dialog. The default options vary between applications, and the options may be changed, saved, and restored within the project.

The following table describes the raster display options.

Display Option	Description
Image Display	Select the "Display as raster" radio button to display the raster as a flat image rather than as a surface with elevation changes. Contour options are applied to form the image with block color fill.
Image Elevation	The raster image is drawn at an elevation of 0.0 by default. Change the "Elevation:" value to draw it at a different elevation.
Surface Display	Select the "Display as surface" radio button to display the raster as a height varying surface rather than as a flat image. Enable either Contours, Edges, or Boundary to see that type of surface or nothing will be shown.
Surface Contour	Select the "Contours" check box to apply contour options to the surface with contour lines and/or smooth color fill.
Surface Edges	Select the "Edges" check box to display the polygonal edges between height samples in the surface. The control to the left sets line color and either enables line dashes or species line width for the edges. This is typically the slowest surface to render.
Surface Boundary	Select the "Boundary" check box to display only those polygonal edges between height samples on the perimeter of the surface. The control to the left sets line color and either enables line dashes or species line width for the boundary. This is typically the fastest surface to render.