Seafloor optical mapping by AUV Gondou: the first sea trial report.

Abstract

A downward-looking optical mapping system was newly installed on AUV （autonomous underwater vehicles） Gondou. This paper presents our approach for seafloor optical mapping using the Gondou, and reports the result of the first sea trial in April 2018. The Gondou dived to a depth of 130－140 m and took photographs at the altitude of 8－10 m. Most of the obtained seafloor images were insufficiently illuminated due to the relatively higher cruising altitude and water turbidity. However, for a part of the images taken above a shipwreck, the image-aligning processes worked well and a photomosaic was created. The optical mapping approach seems to be effective for the seafloor with characteristic and optically high-contrast terrain.