3-D reconstruction of underwater objects using arbitrary acoustic views

This paper presents a method for 3-D measurement of underwater objects using acoustic cameras. The 3-D measurement of underwater objects using arbitrary acoustic views is a major advantage to grasp underwater situations. Robots such as autonomous underwater vehicles (AUVs) and remotely operated underwater vehicles (ROVs) are desired to mount acoustic cameras for underwater investigations, especially in turbid or deep environments. Acoustic cameras are the most powerful sensors for acquisition of underwater information because they have no limitation in their visibility. Furthermore, their sensing area covers wide range, which is often the limitation of traditional sonar sensors. However, 3-D reconstruction systems using acoustic images from arbitrary acoustic views have not been established even with their undeniable worth. In this paper, we propose a novel approach which enables 3-D measurements of underwater objects using arbitrary viewpoints. This approach contributes to establishing a methodology for 3-D shape reconstruction systems, where the correspondences between feature points on each acoustic image are described. The experimental results indicate not only the validity of our proposed approach, but also that the novel methodology demonstrates superior performance in estimating 3-D information of underwater objects.