Sonar aided high accuracy inertial navigation in a partially known environment

P-SURO II is a hybrid AUV which can be operated in both of ROV and AUV modes [1]. In its AUV mode, the vehicle is supposed to carry out some of underwater missions such as inspection and maintenance of complex underwater structures which are usually difficult to be done by ROV or divers due to the cable system. To complete these missions, the vehicle is required to have high level of autonomy, where high accuracy navigation is the most important and basic requirement. In this paper, we present a high accuracy of hybrid inertial navigation method using image sonar in a water tank environment. Various water tank experimental studies are carried out to investigate the effectiveness of presented hybrid navigation method. Some of practical issues of applying image sonar for inertial navigation aiding are also discussed.