Beam-forming and imaging using acoustic lenses: Some simulation and experimental results

The acoustic lens sonar uses lenses instead of electronic circuitry in conventional sonar for beam-forming, so that the electronics complexity and power consumption can be much reduced. Two acoustic lenses are designed in this paper by using the hybrid geometric/wave acoustic model. One is made from the material PMMA(polymethyl methacrylate) and the other is from the material PMP(polymethylpentene). In order to verify the performances of the designed acoustic lenses´ beam patterns, a set of experiments with different objects have been performed in water tanks. The focal position and beam patterns measured in experiments are in accordance with simulation. Therefore, the hybrid geometric/wave acoustic model is proved right and effective to predict the performances of acoustic lenses before fabrication. Besides, images of different objects are also given. According to experimental results, PMMA can be used to design lens for easiness of manufacturing and low sound attenuation.