An acoustic lens sonar using micromechanical hydrophones for unmanned undersea vehicles

The system design of an acoustic lens sonar using micromechanical hydrophones is examined for a mission as the forward-looking sonar on an autonomous underwater vehicle (AUV). Micromechanical hydrophone technology combined with an acoustic lens system can provide a high sensitivity, high resolution imaging sonar system. As the micromachining technology matures, more electronic functions can be integrated on-chip. The partitioning of electronics into on-chip and off-chip blocks is examined. The sensors are small, fluid-filled condenser microphones fabricated on silicon chips. Draper´s developmental work in micromechanical hydrophones is discussed, and sensor performance and optimization are presented for the acoustic lens application. An acoustic lens sonar with a central classification region using thousands of closely spaced sensor elements to provide very high resolution in azimuth and elevation for precision vehicle maneuvers such as rendezvous and docking is described