3D reconstruction of seafloor from sonar images based on the multi-sensor method

This paper proposes a method to estimate the three dimensional aspects of the seafloor using a sequence of sonar images combing GPS positioning. The sonar images are segmented into three kinds of regions using MRF method: echo, shadow and background. The echo information corresponds to the signal back-scattered by the object located on the seafloor while the shadow is due to the absence of back-scattering from behind the object. The remaining information is the background. The reconstruction scheme processes the echo and shadow information separately. A two-dimensional elevation map is estimated from the shadow information and a two-dimensional reflection map is computed from the echoes. And the final reconstruction result merges both of the two maps. The reconstruction result is presented by the experiments using the Matlab simulation in the end of this paper, which prove this method can be implemented in real time as it reconstruct the 3D information successfully and requires only limited computational resources.