Sonar object visualization in an octree

We describe a new method for the detection and visualization of objects in 3D sonar data. The method has been applied to data obtained at a site which contains a well-defined target, being a buried tractor tire, sized 130 cm in diameter and 30 cm high. The surfaces of the corresponding sonar object have been accurately extracted using fast smoothing, filtering, segmentation and surface construction techniques. Analysis shows that the position of the target and the sonar object correctly coincide