Design of a low-complexity miniature underwater three-dimensional acoustical imaging system

Abstract

The conventional beamforming is usually employed in the 3D acoustical imaging system to reconstruct 3D images from the signals received by the 2D array. The angular resolution and sidelobe levels are physically determined by the 2D array used. To obtain the angular resolution 1 degree, the aperture size of the existing system is around 25cm × 25cm in a working frequency of 300kHz. Unfortunately, in some particular applications such as diver handheld equipment, the existing systems are still too large, and the complexity is also high. This paper proposes a low-complexity underwater miniature 3D acoustical imaging system with an aperture size of 15cm × 15cm, 180 elements, and a working frequency of 300kHz. The proposed system introduces the deconvolution algorithm into conventional system design, which is cable to obtain much better image quality than the conventional beamforming. Both the simulation and experiment in this paper demonstrate that in terms of the angular resolution and sidelobe levels, the performance of the proposed miniature 3D system with a much smaller aperture and lower hardware complexity is comparable to that of the existing 3D imaging system.