1887

Abstract

Summary

In SNMR surveys, the electromagnetic (EM) perturbations originating from powerlines infrastructures is often the main EM noise source that contaminates the SNMR acquisition signal. The removal of these harmonic signals is therefore critical to extract the data and carry out the study. To date, some techniques exist that give satisfying results in many cases, provided that the assumptions of a harmonic noise based on a single and constant fundamental frequency are valid. However, when these conditions are not met and the characteristics of the harmonic noise become more complex, these methods will fail to remove it correctly. In this paper, we show how such complex conditions will affect the frequency spectra of the SNMR acquisition signal. Then, we address the issue of a harmonic noise composition based on two different fundamental frequencies, by solving the non-linear optimization problem simultaneously for the two frequency values, using a 2D grid-search. Then we investigate the case where the fundamental frequency of the harmonic signal is not constant but variates within the signal duration. We expose a new approach based on the Nyman and Gaiser estimator, which, associated with a signal bootstrapping strategy, efficiently handles this situation.

Loading

Article metrics loading...

/content/papers/10.3997/2214-4609.201802552
2018-09-09
2024-04-20
Loading full text...

Full text loading...

References

  1. Adams, R. K., McIntyre, J. M., & Symonds, F. W.
    (1982). Characteristics of the eastern interconnection line frequency. IEEE Transactions on Power Apparatus and Systems, (12), 4542–4547.
    [Google Scholar]
  2. Butler, K. E., & Russell, R. D.
    (1993). Subtraction of powerline harmonics from geophysical records. Geophysics, 58(6), 898–903.
    [Google Scholar]
  3. Hein, A., Larsen, J. J., & Parsekian, A. D.
    (2016). Symmetry based frequency domain processing to remove harmonic noise from surface nuclear magnetic resonance measurements. Geophysical Journal International, 208(2), 724–736.
    [Google Scholar]
  4. Jiang, C., Lin, J., Duan, Q., Sun, S., & Tian, B.
    (2011). Statistical stacking and adaptive notch filter to remove high-level electromagnetic noise from MRS measurements. Near Surface Geophysics, 9(5), 459–468.
    [Google Scholar]
  5. Larsen, J. J., Dalgaard, E., & Auken, E.
    (2013). Noise cancelling of MRS signals combining model-based removal of powerline harmonics and multichannel Wiener filtering. Geophysical Journal International, 196(2), 828–836.
    [Google Scholar]
  6. Legchenko, A., & Valla, P.
    (2003). Removal of power-line harmonics from proton magnetic resonance measurements. Journal of Applied Geophysics, 53(2–3), 103–120.
    [Google Scholar]
  7. Müller-Petke, M., Braun, M., Hertrich, M., Costabel, S., & Walbrecker, J. (2016). MRSmatlab—A software tool for processing, modeling, and inversion of magnetic resonance sounding dataMRSmatlab. Geophysics, 81(4), WB9–WB21.
    [Google Scholar]
  8. Nyman, D. C., & Gaiser, J. E.
    (1983). Adaptive rejection of high-line contamination. In SEG Technical Program Expanded Abstracts 1983 (pp. 321–323). Society of Exploration Geophysicists.
    [Google Scholar]
  9. Saucier, A., Marchant, M., & Chouteau, M.
    (2005). A fast and accurate frequency estimation method for canceling harmonic noise in geophysical records. Geophysics, 71(1), V7–V18.
    [Google Scholar]
http://instance.metastore.ingenta.com/content/papers/10.3997/2214-4609.201802552
Loading
/content/papers/10.3997/2214-4609.201802552
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