1887

Abstract

Summary

There are a lot of methods for the computation of the attenuation including the time-domain methods and frequency-domain methods. The frequency-domain method is widely used at the present stage due to the strong adaptability and stability of the frequency-domain method, including spectral ratio method, the frequency shift method, peak frequency shift method. All these three methods are affected by the windowing effects, that is, the type of window and the length of window. The windowing effects affect the stability and accuracy of the estimation of Q value. Then a new method for the computation of ultrasonic attenuation based on time-frequency analysis is presented. S transform is selected as the time-frequency transform method. The amplitude spectrum of the maximum energy in the time-frequency spectrum is selected to calculate the Q value based on the principle of the spectral ratio method. The feasibility of the method is analyzed through numerical simulation data. In addition, the accuracy and stability of this method are analyzed through standard sample and physical models.

Loading

Article metrics loading...

/content/papers/10.3997/2214-4609.201801409
2018-06-11
2020-05-31
Loading full text...

Full text loading...

References

  1. Stockwell, R. G., MansinhaL., and LoweR. P.
    , 1996, Localization of the complex spectrum: The S transform: IEEE Transactions on Signal Processing, 44, no. 4, 998–1001
    [Google Scholar]
  2. Tonn, R.
    , 1991, The determination of the seismic quality factor q from vsp data: a comparison of different computational methods 1. Geophysical Prospecting, 39(1), 1–27.
    [Google Scholar]
  3. BathM.
    , 1974. Spectral Analysis in Geophysics. New York: Elsevier.
    [Google Scholar]
  4. Zhang, C. and Ulrych, T. J.
    , 2002. Estimation of quality factors from cmp records. Geophysics, 67(10), 1542–1547.
    [Google Scholar]
  5. Quan, Y., and HarrisJ. M.
    , 1997, Seismic attenuation tomography using the frequency shift method: Geophysics, 62, 895–905.
    [Google Scholar]
  6. ZemanekJ and RudnickI.
    , 1961. Attenuation and Dispersion of Elastic Waves in a Cylindrical Bar. Journal of the Acoustical Society of America, 33(10):1283–1288.
    [Google Scholar]
  7. TangX M, ToksözM N and ChengC H
    ., 1990, Elastic wave radiation and diffraction of a piston source. Journal of the Acoustical Society of America, 87(5):1894–1902.
    [Google Scholar]
http://instance.metastore.ingenta.com/content/papers/10.3997/2214-4609.201801409
Loading
/content/papers/10.3997/2214-4609.201801409
Loading

Data & Media loading...

This is a required field
Please enter a valid email address
Approval was a Success
Invalid data
An Error Occurred
Approval was partially successful, following selected items could not be processed due to error