Extraction of coral bleaching by using high resolution satellite imagery

In this research, we propose the technique of extracting the coral bleaching from a satellite image, carry out the simulation experiment in order to verify the effectiveness. It is an image of Taketomi-island in Japan photographed by high resolution satellite IKONOS. The sample pixels are extracted from each area in coral bleaching, dead coral, living coral, sand in sea, deep sea, and wood. The coral bleaching characteristics appear in the Red and the Blue band, when the distribution of Red, Green, Blue, Nir-infrared is respectively compared using the multivariate analysis. This paper derives a function which enhance these characteristics. The results of extraction experiments show accuracy improved by our proposed method.