Detection of pair-trawling ships using ALOS-2/PALSAR-2 data

Abstract

In this study, we detected pair-trawling ships using a synthetic aperture radar that can observe fisheries without a fishing lamp. Automatic detection of pair-trawling ships is possible by extracting all ships from the image, examining the distance to the surrounding ships from each ship, and using the combination that minimizes the distance between ships as a pair. For the cases where the ship pair is incorrect, correction methods are presented. In addition, in order to understand the activities of the pair-trawling ships in the target area, the density of pair-trawling ships and distance between ship pairs is calculated. In this study, if sufficient data can be obtained during the fishing season, there is a possibility to estimate fishing effort.