Research On The Sediment Velocity Dispersion And Attenuation Experiment Data Processing Method

With the gradual development of marine technology,the characteristics of seabed sediments in the military and civilian applications are increasing,while accurate and fast access to the acoustic properties of seafloor sediment parameters technology has become an important part of today's marine research.For sediment acoustic characteristic parameters of acoustic velocity and attenuation coefficient calculation,the extraction of time delay and amplitude is particularly important.When transmitting signal is a narrowband signal,in order to obtain higher precision delay estimation on time delay estimation method must be super-resolution applications.This paper mainly studies the measurement of sound velocity and acoustic attenuation and the processing of experimental data,in order to achieve the sediment characteristic parameters acquisition and the extraction of signal delay,experiment is an object with sandy sediment,was studied sediment characteristic parameters under laboratory conditions,and super resolution time delay of the experimental data are extracted.Firstly,this paper summarizes the sound velocity and attenuation in the seabed sediment measurement method,then introduces the development process and the time delay estimation algorithm,and sums up the super resolution time delay estimation method based on narrow-band signals,including cross-correlation method,DL-LS,DL-LS-MUSIC and WRELAX,and it is given based on large amounts of data by matlab under different conditions,the time delay estimation performance of the algorithms are compared and analyzed.Comprehensive four performance of the algorithm under different situation DL-LS-MUSIC algorithm is the highest resolution,followed by DL-LS algorithm,again for WRELAX algorithm,is copied to a low resolution of correlation method,but it is suitable for low signal noise ratio(SNR).Further described emphatically the sandy sediments acoustic velocity and attenuation measurement experiment,after the experimental data through data processing and signal analysis,found WRELAX algorithm and cross-correlation method of velocity of sound processing results are basically consistent,but DL-LS algorithm processing results slants big,then summarized the three classic sediment sound propagation model(including the Biot theory,EDFM and Buckingham model)and compared with the results analysis,the results found WRELAX algorithm and cross-correlation method of velocity of sound processing result with Biot and EDFM velocity dispersion curve is relatively close,and the velocity of DL-LS algorithm and Buckingham model curve is close to the results.Finally,using LabVIEW platform that has been collected by cross-correlation analysis processing the experimental data of the signal to get the sound velocity and attenuation coefficient of sediment.The measurement results and the forecast results of three kinds of classical sound propagation model analysis.Prominent part of the software is automatically after the user input the keyword search matching files in the folder,and analyzing the experimental data was tested and verify the reliability of the system,and the extraction of signal information and features,after further analysis of the signal processing can not only achieve expected effect,and showed the real-time function of this system,more embodies the powerful.