Dev Prakash Satsangi

"Acoustical Considerations in Design of SONAR Domes". SONAR (Sound Navigation and Ranging) system is used for detection, classification and localization of underwater objects using sound waves. Quite often, acoustic projectors used in sonar applications are housed inside a chamber, known as a sonar dome. Sonar domes are typically attached to lower front part of ship and used for performing two key operations. First the dome's wall protects the projector against the pressure exerted by the high speed sea water, Hydrostatic pressure, and impact forces attributable to different sea objects. Secondly, dome walls facilitate easy transmission of acoustic waves generated by the projector out into the sea. For this reason, walls of a sonar dome should be ideally acoustically transparent. However, in reality, dome walls should be made up of a material which provides for minimum "insertion loss" for transmission of the acoustic waves. Thus, design of sonar domes requires an exercise in optimization by balancing the conflicting requirements of acoustical transparency and mechanical strength. In this project, we plan to explore and develop a design methodology for a typical sonar dome for ship applications. As a part of this exercise, we plan to explore diverse design parameters such as dome material, thickness of dome's wall, shape of the dome, position of the array in the dome, role of baffle inside the, insertion loss, leakage of external noise into the dome, Anechoic performance, etc.