Using sonar in terrain-aided underwater navigation

In many ways autonomous navigation of underwater vehicles is a `holy grail´ of subsea robotics. For an AUV to continually estimate its pose (position and orientation) and operate within an initially unknown environment a solution is required to the simultaneous map building and localisation or `SLAM´ problem. The paper describes and investigates an inertial and terrain based approach to this problem. The fusion of body frame inertial and sonar based world frame feature information can form part of a robust navigation algorithm suitable for implementation in both artificial and natural environments. Particular attention is given to the role of the sonar and its ability to detect and track terrain features