1. A method of tracking a known object immersed in a sound wave transmitting medium, comprising: a) sending sonar signals from a sonar signal generator towards the known object; b) receiving sonar signals reflected from the known object and from other objects near the known object, the sonar signals received by a sonar signal receiver; c) calculating from the received sonar signals the three dimensional (3D) positions of a set S 1 of sonar imaging points P, wherein the points P are on the surface of the known object and on the surfaces of the other objects near the known object; d) defining a closed bounding sphere around the known object, the bounding sphere having a radius sufficient to surround all points on the surface of the known object, wherein the distance between the surface of the bounding sphere and all points on the surface of the known object has a defined minimum; e) removing sonar image points P e from the set S 1 , wherein sonar image points P e are exterior to the bounding sphere; f) adding sonar image points P o to a set of occlusion points S 3 , wherein the sonar image points P o are interior to the bounding sphere and greater than a defined distance from the surface of the known object; g) removing the set S 3 of occlusion points from the set S 1 ; h) generating a 3D image of the known object calculated from the set S 1. i) moving the object; j) repeating steps a)-h).