2014 年 41 巻 4 号 p. 169-182
To track individual fish within a dense school, it is necessary to isolate the echoes from multiple individual fish and then estimate their positions accurately. The signals from a broadband split-beam system offer the advantage of high-range resolution for this purpose. The range resolution and localization accuracy of this system were investigated by measuring the echoes from spheres in a tank. A tracking method exploiting the high-range resolution of the broadband signal was proposed. Echoes from schools of Japanese anchovy were measured in the ocean. Individual fish in these schools were measured separately and tracked using the proposed method. The technique allowed for accurate tracking of individual fish within dense schools. The estimated tracks can help us to better understand fish behavior under the sea.