| The Ocean Bottom Seismometer(OBS)is a new type of seismic recording instrument that placed on the seabed.Without the influence of seawater,it can record P and S waves generated by earthquakes,and obtain seismic data with higher signal-to-noise ratio.Therefore,it is widely used in natural seismic(passive source)observation and offshore artificial seismic(active source)exploration.This paper summarizes the application of OBS in natural seismic and artificial seismic exploration,formed an understanding of OBS detection technology.Subsequently,we studied the data preprocessing method of OBS,includes data format conversion and time correction,OBS relocation and reorientation,amplitude compensation,filtering and deconvolution,wave field separation.This paper has done the above processing on the actual data and got good results.However,the above processing cannot solve the problem of OBS loss or data anomaly.Based on the research of preprocessing methods,this paper uses interpolation method to solve the above problems.Through MATLAB programming,this paper compares the results of amplitude interpolation calculation with four interpolation methods.The results shows that the best interpolation effect is spline interpolation,and interpolation results are affected by changes in offset.Based on the above research,we apply the interpolation method to the actual data.Firstly,we wrote the MATLAB program to read the seismic wave amplitude.An automatic search step is added to the program to search for amplitude values in the time window range of five sampling points above and below the picked travel time,and taken the maximum value as the desired amplitude value.The application of results shows that the program can read amplitude values quickly and accurately.Secondly,we wrote a MATLAB program for OBS data interpolation and interpolated M2 stations with direct wave amplitudes of M1 and M4 stations.Compared the interpolation results with the actual records,it is found that the interpolation result is consistent with the actual record.Finally,we calculated the amplitude of the missing OBS(M3)by spline interpolation.It makes up for the lack of data,and lays the foundation for subsequent data processing. |
