Development And Experiment Of A Variety Of Waveform Sound Sources For Measuring The Acoustic Properties Of Seafloor Sediments

Acoustic properties of seafloor sediments is the underlying data of studying the Ocean acoustic field environment, is indispensable research contents in constructing geo acoustic model and provide the basic data and the key technology for seabed classification and exploitation of marine resources, national defense and security.The sound velocity and attenuation coefficient are two important parameters to reflect the sound characteristics. The physical properties and the internal structure of the seabed sediments can be distinguished by their measurement.This time domain pulse wave measurement method, usually requires manual interpretation of the first wave information collected.At present, the measurement of acoustic characteristics of seabed sediments is mainly based on the pulse wave transmission method. This pulse wave measurement method, usually requires manual interpretation of the first wave of information collected.Due to the uneven sediment media,large transmission sound attenuation,the acquisition of the acoustic wave signal waveform is not stable, to bring disturbance to the manual interpretation.Based on this situation, this paper introduces a new waveform measurement method, and develops a waveform generator,to try a variety of time domain waveform to measure the seafloor sediment.This paper introduces the present situation of the acoustic characteristics of the seabed sediments, including the measurement of the laboratory and in situ measurement.In the measuring principle, on the basis of traditional pulse wave measuring method of analysis , innovatively put forward of seafloor sediments with continuous wave (sine wave, amplitude modulation wave) cross-correlation measuring sound velocity and autocorrelation measurement principle of acoustic attenuation, and gives the calculation method.In the development of measurement device, sound source hardware part of the circuit board signal, the driving circuit board and isolated power composition; in terms of software, the MCU program using C language and based on VB PC and single-chip communication design can realize continuous wave frequency control and hardware circuit mode control.Based on the preliminary study of the project team, the experimental platform of small scale ultrasonic probe measurement and acoustic signal acquisition is set up.Finally, the function of a variety of waveform sound source device is verified, and the feasibility of the method is verified.Based on the analysis of the collected data, the experimental results of the acoustic characteristics of the seafloor sediment were obtained.Compared with the traditional method of pulse wave measurement, the method of continuous wave measurement can be applied to the rapid extraction of acoustic parameters of seabed sediment by the related computer technology and MATLAB software.The development of a variety of waveform sound source device provides the basic conditions for the exploration of the seabed sediment measurement method, and lays the foundation for the further research.The research work of this paper can be summarized in this paper. The multiple waveform sound source devices can work stably. The measured waveforms show that the continuous wave profile is more stable and the acoustic properties of the sediments are more promising.Based on the problems and deficiencies found in the test operation and data calculation, a further improvement measures and suggestions are put forward.