Method for Finding Range and Bearing to Underwater Object

A method for localizing the range and bearing of a distant underwater object, the method comprising the steps of:

• firing a preselected number of supercavitating projectiles sequentially with each supercavitating projectile tracking along substantially the same trajectory, each supercavitating projectile further being preset to disperse a plurality of supercavitating pellets stored therein over a wide volume pattern that spreads orthogonal to said trajectory at a unique, pre-selected range from the firing location, the plurality of volume patterns thus produced by said corresponding supercavitating projectiles further being closely spaced along said trajectory, whereby a small number of projectiles thus serves to cover a large volume along and across said trajectory;
• sensing acoustic signals produced by supercavitating pellet impact with the distant underwater object to obtain acoustic signal return data using an acoustic sensor located proximate the firing location, said pellet impact producing a detectable characteristic bubble collapse signature return of higher amplitude and distinctive pulse length;
• and
• processing said acoustic signal return data using a signal processing system connected to said acoustic sensor to determine object range and bearing data from said acoustic signal return data.