An Acoustic Beacon Detection System Based On Wavelet Packet Transform

The Underwater acoustic beacon is one of the most commonly used ocean acoustic instruments. It is installed in the underwater carrier and transmits signals according to certain rules. In this paper, we introduce an underwater acoustic beacon detection system based on a wavelet packet transform. The system is composed of a ruggedized computer, a directional receiving transducer, an angle sensor, a detection bracket et al. The ruggedized computer is equipped with signal conditioning module, signal acquisition and processing module, and single board computer. In the signal acquisition and processing module, the wavelet packet transform and the traditional weak signal extraction method are used to extract and identify the signal which transmits from the acoustic beacon. The detection results are shown in the form of audio and video. This system is easy to operate. Meanwhile, using hardware broadband filtering and DSP module narrowband filtering, the system can realize multi-frequency detection of underwater acoustic beacons. Experimental results show that, because of the use of the wavelet packet transform, the detection distance can be increased by 20 percent as compared to a system using the matched filtering method.