Research On The Method For Extracting The Acoustic Characteristics Of The Ocean Sediment And Signal Processing

The extraction of acoustic characteristics of ocean sediment has great importance to civil and military activities. This thesis focuses mainly on the extraction of sound speed of ocean sediment. A seabed model for extracting the acoustic characteristics of ocean sediment has been established. The principia of correlation analysis and wavelet transform as well as their applications in the seabed echo data processing have been studied thoroughly. Based on the seabed model for extracting the acoustic characteristics of ocean sediment and using the MATLAB software, the envelope analysis of seabed echo data has been conducted, the arrival time of the acoustic waves refracted by the first sediment has been obtained, and the sound speed of ocean sediment has been extracted by applying the two algorithms of correlation analysis and wavelet transform, respectively. The research in this thesis has shown that both the correlation analysis and wavelet transform can be used to extract the sound speed of ocean sediment, and the extracted sound speed is in accordance with the reported value in some literatures within the error limits. A comparison between the results obtained by using the two algorithms shows that the deviations of sound speed from the wavelet transform algorithm are smaller than those from correlation analysis algorithm, which demonstrates that the wavelet transform can not only raise the signal-to-noise ratio but also keep high time resolution, so it is more suitable for seabed echo data processing. The research conducted in the thesis provides not only a feasible idea for the study of acoustic characteristics of Deep Ocean, but also some important references for the development and utilization of seabed resources in the future.