Abstract
Visual investigation of an accidental sinking is necessary to identify the accident and determine its causes. We are developing an AUV for this purpose and propose a wreck observation system for AUV (Autonomous underwater vehicle) without transponder-based positioning systems that need a costly preparation. This paper proposes a terrain based localization method to accurately determine the AUV's position. The method is conceptually simple: The AUV measures topography of the bottom using multibeam sonar, and correlates the measurements with an existing map. The proposed method is robust and computationally efficient compared to other methods that are used for terrain navigation. We also present the simulation results using data of a sea trial in order to demonstrate its effectivity.