Extraction of marine debris in the Sea of Japan using satellite images

It is important to understand the flow of marine debris for environmental research purposes, since marine debris causes extensive damage to coastal environments. Due to its small size, most marine debris in the ocean cannot be confirmed directly, even when a high-spatial-resolution satellite image is used. Thus, to extract candidate pixels containing possible marine debris, pixels with spectra that differ from those of the surrounding ocean are identified. As a first step towards identifying and monitoring marine debris, a method using spectral angle mapper (SAM) algorithm in n-dimensional space corresponding to the satellite spectral bands was previously proposed. In this paper, a method to discriminate marine debris from white-crested waves is proposed using the distance from the origin in an n-dimensional scatter diagram. Moreover, it is also discussed that the relationship between the distance from the coast and the amount of marine debris depends on the locations of the sea currents and neighbouring rivers.