测量海底沉积物声学特性的多种波形声源开发与实验机械工程专业论文.docxVIP

ABSTRACTAcoustic ABSTRACT Acoustic properties of seafloor sediments is the underlying data of studying the Ocean acoustic field enviroment，is indispensable research contents in constructing geo acoustic model and provide the basic data and the key techno logy 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 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 waveform generator，to try a variety of time domain waveforna 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 s