Cocos Island - Hillshade - 2011
In 2013 a hillshade image (similar to the shiny colour drapes) was produced from the 2011 digital elevation model. The hillshade shows the ground surface underneath trees and buildings and was created in ArcMap using an azimuth of 315 and an altitude of 45. A vertical exaggeration of 10 was applied to highlight elevation differences. The hillshade covers the full extent of the Cocos (Keeling) Islands. The ESRI ArcGIS Resource Centre describes a hillshade image as :
“A hillshade is a grayscale 3D model of the surface, with the sun's relative position taken into account for shading the image. This function uses the latitude and azimuth properties to specify the sun's position.”
The hillshade image can be viewed as a greyscale image, or underneath the DEM (if semi-transparent). It can also be viewed under any other layer to show the lie of the land, for example orthophotography, canopy heights or infrastructure.
The hillshade was created from the 2011 DEMwhich is vertically accurate to 15cm and horizontally accurate to 30cm.
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