Autonomous survey system of manganese crusts using acoustic and visual instruments

In order to effectively investigate the distribution and amount of CRC (Cobalt-Rich manganese Crust) an AUV BOSS-A equipped with visual and acoustic instruments were developed. The AUV observes CRC on the seafloor along preset waypoints at a constant speed and altitude. Detailed 3D seafloor image is created based on navigation data from the AUV and images from visual instrument. In addition, an acoustic instrument measures the CRC thickness. We surveyed the CRC at Katayama seamount in February 2015. The results visually presented distribution of the CRC in this site. In the future, we will develop a reliable, accurate measurement method for CRC thickness by combining visual and acoustic instruments.