Laser Doppler interferometer can be used to measure the diagonal group velocities and further help to obtain the anisotropic parameters (especially for δ) on shale. It has many advantages over the commonly used transducer-based approaches. However, the strong erratic noise introduced during the excitation, transmission and receiving processes will decrease the quality of recorded waveform. We propose a novel median filtering based approach for removing such erratic noise. Instead of directly applying the median filter along the spatial direction, we apply median filter along the structural direction of the waveforms. The principle of such median filtering is to apply a median filter along the spatial direction in a locally flattened processing window. Considering that the structural-oriented median filter will require an accurate estimation of local slope of waveforms, in the case of imperfect slope estimation, the local processing window cannot be flattened well, which will still make the traditional median filter fail. To deal with this problem, we propose to apply a space-varying median filter along the structural direction to mitigate the influence caused from imperfect flattening. We apply the proposed algorithm onto one synthetic example and real recorded data from the Laser Doppler interferometer to show a successful performance.


Article metrics loading...

Loading full text...

Full text loading...


  1. Chen, Y.
    [2015] Deblending using a space-varying median filter. Exploration Geophysics, 46, 332–341.
    [Google Scholar]
  2. Gan, S., Wang, S., Chen, Y., Chen, X. and Xiang, K.
    [2016] Separation of simultaneous sources using a structural-oriented median filter in the flattened dimension. Computers & Geosciences, 86, 46–54.
    [Google Scholar]
  3. Xie, J.
    [2015] Enhancement of inversion accuracy of thomsen parameter delta on shale: based on experimental and theoretical improvement. SEG Technical Program Expanded Abstracts, 432–436.
    [Google Scholar]

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