Underwater imaging using acoustic lens

Acoustic vision systems are gaining prominence due to ocean surveillance for internal security along coastal waters, in particular defence and engineering. Image generation is an effective method for underwater target exploration. Underwater acoustic imaging systems can identify objects according to the characteristic information obtained from the acoustic reflections from the object. Acoustic lens is an attractive device for underwater imaging sonar because of its imaging capability without complex beamforming. This paper discusses the design and development of spherical and cylindrical acoustic lenses with plano-concave and double concave shapes and also development of imaging transducer array operating at 500 kHz. Acoustic lenses in combination with transducer arrays were evaluated underwater for acoustic imaging applications.