Imaging sonar based 3D scanning method of underwater terrain for AUVs

This paper proposes a method based on an imaging sonar to obtain underwater terrain information. The proposed method utilizes mobility of the AUV and characteristics of the imaging sonar. We reconstructed three-dimensional(3D) information by estimating the elevation angle for a portion of the sonar image. We created a 3D point cloud by scanning the seafloor. We can use the 3D point cloud to detect objects and to select landmarks. To verify the feasibility of proposed methods, we conducted field experiments using a hovering-type AUV ‘Cyclops’.2