A real-time 3D underwater acoustical camera

Imaging with acoustical lenses in the low MHz frequency range using fully populated 2D arrays offers the potential for high resolution, real-time, 3D volume imaging together with low power and low cost. This 128x128 (16,384 total) element Transducer Hybrid Array (THA) uses massively parallel, on-chip signal processing and is intended for medical and underwater imaging applications. Traditional electronic beamforming for underwater imaging applications requires large amounts of fast signal processing with high electrical power consumption, particularly if any parallel beamforming is used. In contrast, an acoustical lens beamformer uses zero electrical power and can be fabricated at very low cost. The system under development, which is a direct analog of a video camera, will be discussed in this paper.