An Underwater Photogrammetric Application to Generate Micro-Bathymetry Data for Benthic Habitat Mapping and Analysis at Arctic Ocean

Abstract

The Ocean Floor Observation and Bathymetry System (OFOBS) is an underwater survey platform, which is designed and developed for research in the Polar Regions by the Alfred Wegener Institute (AWI). The tailored deep tow system brought a new perspective and clarity from Arctic Ocean by its optical and acoustic sensors. During the PS101 expedition at the Karasik seamount, OFOBS provides a novel picture of megafauna’s habitats. In this study, we develop a methodology to convert the imagery dataset to micro-bathymetry in order to provide primary data for object detection and habitat mapping which will provide a better understanding of arctic benthic habitats. The methodology is based on the underwater photogrammetry workflow and two different point cloud classification methods adopted for sponge detection in 3D point clouds, to facilitate habitat mapping with a focus on the central of Karasik seamount where an extensive and dense assemblage of the Geodia sponges is dominating the seafloor.