Robust Sonar-Based Underwater Object Recognition Against Angle-of-View Variation

Underwater object recognition based on deployed mobile nodes (underwater vehicles) is difficult, because the shape of an object in a sonar image is significantly changed depending on the direction from which the object is approached. The approaching directions of deployed mobile nodes cannot be predicted in advance. To solve the problem, the conventional underwater recognition algorithms use realistic template images generated by sonar image simulators, and compare the template images to the actual sonar image. However, the realistic sonar image simulation is computationally complex, and the comparison requires some preprocessing methods, such as image segmentation. To solve the problem, this paper proposes a sonar image simulator-based underwater object recognition algorithm. The proposed algorithms that is motivated by the generation mechanism of a sonar image can directly compare the actual sonar image and the simulation image generated by a simple sonar image simulator.