Obtain the phase velocity of ocean waves by using distributed acoustic sensing

Abstract

In the field of ocean and seismic wave detection, the distributed acoustic sensing based on chirped pulse is used to obtain the specific information of different waves and to dig out the available effective content. But with the huge amount of data, there will be some problems of low computational efficiency and long processing time. This paper applies image processing methods to analyze the phase velocities of different waves. The method combines different technologies to get the related analysis more quickly. Specifically, on the basis of the original data, the two-dimensional Fourier transform processing is performed on the two-dimensional matrix as preprocessing, and then the edge detection algorithm and the operation of color inversion is used to process the data of 20-30 kilometers. After that, all the results are converted into scatter plot form. Then the required scatter points need to be kept and fitted, and this step contributes to obtaining the range of phase velocity variation of different waves through the tangent of the fitted curve. The final result is in line with the phase velocity of the actual situation analysis, and the process is more convenient. The methods proposed in this paper are more convenient to calculate, and they reduce the workload. As a result, they are suitable for monitoring the phase velocity of seismic wave and ocean wave detection.