Image Processing and Analysis: Channel Combination and Color Enhancement

The image below is from the NASA MODIS satellite. It shows the snow left in midwestern states on December 1, 2006 after a storm passed through. The tool below the image lets you apply data from a single MODIS instrument channel to each of the Red, Green, and Blue color components of a new, generated image.

Your Task

• Use various channel combinations to make a feature stand out in an image that is otherwise difficult to identify. For example, try applying Channel 1 to Red, Channel 4 to Green, and Channel 3 to Blue. This combination gives a "true color" effect, which makes the broad swath of snow cover with a very sharp edge stand out clearly.
• What's not clear viewing this channel combination is the fact that freezing rain from this storm left a very large area extending from northern Missouri to south-central Iowa covered in ice. This is not visible in a "true color" image since ice does not alter the albedo or general appearance of the ground. However, by applying the right combination of ice-sensitive channels, this feature can be revealed. Try applying Channels 2, 7, and 7 to see this.

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