Dolphin-inspired sonar system and its performance

The sonar of dolphins has developed over millions of years of evolution and has achieved excellent performance levels. Using the excellent performance of the dolphins sonar as an inspiration, bio-inspired wideband acoustic sensing methods for underwater target detection and tracking are being developed. In this study the authors explore what they expect to gain from such a wideband sonar. The systems wideband sensors are based on bottlenose dolphins sonar, covering a frequency band from around 30 to 150 kHz and having a frequency dependent beamwidth considerably larger than that of conventional imaging sonars. The system can be made relatively compact and is suitable for mounting on a variety of platforms including small-scale autonomous underwater vehicles to allow the sonar to operate in a similar way to that used by dolphins. In contrast to high-resolution image processing techniques, detection and classification in the wideband system are based on pattern recognition methods applied to the echo spectra. The authors highlight the properties of the transducers needed for such a system indicating how these properties may be exploited to give improved sonar performance. The results obtained from such a system are presented to illustrate the effectiveness of this approach.