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Unformatted text preview: the Ice Lake
Basin bookmark that you viewed earlier in ArcMap. The four major lakes are shown (from
southwest to northeast – Fuller Lake, Ice Lake, Island Lake, and Clear Lake).
Return to the Ophir 3D view bookmark.
3. In ArcToolbox beneath the Table of Contents, double click on the 3D Analyst Tools toolbox,
followed by the Raster Surface toolset. Double click on the Hillshade tool. In the Hillshade dialog
box, choose the Ophir DEM layer as the input. Click the button to the right of the Output raster
box. In the Save As dialog box, browse into your lab9\data3D folder. Type hillshade in the Name
3 box. Click the Save button. In the dialog box, the azimuth and altitude values indicate the position
of the artificial illumination source relative to the landscape. Azimuth values can range from 0° to
359°, while altitude values can range from 0° to 90°. The default values shown in the Hillshade
dialog box indicate that the fake sun will be shining from the northwest (315°) and be 45° above
the horizon. Do not change these default values, or the Model Shadows or Z factor settings. Click
the OK button. The hillshade processing status will appear for a few seconds near the bottom
right corner of the ArcScene window. When the processing is finished, turn off the Ophir DEM
layer, but do not remove it from the Table of Contents.
4. Examine the hillshade values listed in the Table of Contents. The values range from a low of 0
to a high of 254. These are not elevation values; they are simply indications of brightness in the
hillshade image. Based on the artificial illumination source, grid cells with values of 0 were in
complete shadow, while values of 254 indicate full sun. Open the Layer Properties dialog box
for the new hillshade layer. Click the Source tab. The information beneath this tab includes
various characteristics of the raster data set (the cell size at 10 m x 10 m, the uncompressed
size of the DEM in MB, the map extent in UTM northings and eastings, the projected coordinate
system and datum, etc.). Click the Symbology tab. Raster layers such as DEM...
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This document was uploaded on 04/01/2014.
- Fall '14