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Derivation of Coastal Changes using Two Radar Backscatter Intensity Images.

RADAR BACKSCATTER INTENSITY

The roughness of the surface has the greatest influence on radar backscatter. A flat sea surface without waves, for example, gives no backscatter to the satellite and is imaged as black.

COLOR ADDITIVE PROCESS

The additive process between red (R,G,B) = (100%,0%,0%) and cyan (R,G,B) = (0%,100%,100%) results in white (R,G,B) = (100%,100%,100%). First, convert colors in radar images from gray-scale in image before the earthquake to red-scale and from gray-scale in image after the earthquake to cyan-scale. Second, the additive process between the red-scale and the cyan-scale results in gray-scale, red-scale and cyan-scale at unchanged area, area where backscatter decreased, and area where backscatter increased.

COLOR ADDITIVE PROCESS
Coastal Change Inferred from Satellite Synthetic Aperture Radar Images

Before earthquake
Radar image
After earthquake
Radar image
Comparison image
Coastal change
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An area colored in red in the image below is a region where the reflective (backscatter) intensity is decreased due to submergence and Tsunami inundation.
Western coast of northern Sumatra.
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2003/07/22 2004/12/31 After additive process

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