Acoustic Imaging in Three Dimensions

An algorithm and method of implementation are described for obtaining high-resolution, three-dimensional acoustic images of simple objects in air using only a small number of transducer positions. Each transducer position provides a single large bandwidth pulse-echo waveform along a specified incident direction. Probabilistic estimation procedures using the full waveforms are used to reconstruct a three-dimensional image of the objects in the observed volume. Prior information about the physics of the scattering process, the statistical nature of the noise and the acoustic reflectivity of the target object are used to obtain resolution of the order of the smallest wavelength present in the acoustic pulses. Results of both synthetic and experimental tests of the algorithm are presented, as well as a brief description of the experimental apparatus and the algorithm used.