Estimation of harmonic interference parameters of surface-NMR signal using an adaptive method and residual signal power

نوع مقاله: مقاله تحقیقی‌ (پژوهشی‌)

نویسندگان

موسسه ژئوفیزیک دانشگاه تهران

چکیده

Surface nuclear magnetic resonance (surface-NMR) method is a well-known tool for determining the water-bearing layers and subsurface resistivity structure. Harmonic interference is an inevitable interference in surface-NMR measurements. Accurate estimation of harmonic interference parameters (i.e., fundamental frequency, phase and amplitude) leads to better retrieval of power-line harmonics and consequently, more effective suppression of harmonics from surface-NMR recordings. To that end, two algorithms are addressed for isolation and then subtraction of harmonic interfering noise based on modeling of power-line harmonics by a modified version of Nyman-Gaiser estimation (NGE) and residual signal power (RSP) technique. Then, the results derived from the proposed algorithms are analyzed and compared through the modeling of some synthetic signals embedded in simulated noise and real recordings obtained from multi-channel surface-NMR measurements. The numerical experiments on simulated and real surface-NMR signals show that the application of the proposed procedures results in significant decline of the level of the standard deviation of imaginary part of the detected signal and consequently, relatively accurate recovery of the harmonic signal components with an accompanying enhancement in estimation of the surface-NMR signal parameters.

کلیدواژه‌ها


عنوان مقاله [English]

Estimation of harmonic interference parameters of surface-NMR signal using an adaptive method and residual signal power

نویسندگان [English]

  • Reza Ghanati
  • Mohammad Kazem Hafizi
Institute of Geophysics, University of Tehran
چکیده [English]

Surface nuclear magnetic resonance (surface-NMR) method is a well-known tool for determining the water-bearing layers and subsurface resistivity structure. Harmonic interference is an inevitable interference in surface-NMR measurements. Accurate estimation of harmonic interference parameters (i.e., fundamental frequency, phase and amplitude) leads to better retrieval of power-line harmonics and consequently, more effective suppression of harmonics from surface-NMR recordings. To that end, two algorithms are addressed for isolation and then subtraction of harmonic interfering noise based on modeling of power-line harmonics by a modified version of Nyman-Gaiser estimation (NGE) and residual signal power (RSP) technique. Then, the results derived from the proposed algorithms are analyzed and compared through the modeling of some synthetic signals embedded in simulated noise and real recordings obtained from multi-channel surface-NMR measurements. The numerical experiments on simulated and real surface-NMR signals show that the application of the proposed procedures results in significant decline of the level of the standard deviation of imaginary part of the detected signal and consequently, relatively accurate recovery of the harmonic signal components with an accompanying enhancement in estimation of the surface-NMR signal parameters.

کلیدواژه‌ها [English]

  • surface-NMR signal
  • harmonic interference
  • parameter estimation
  • signal power
Butler, K. E., and Russell, R. D., 1993, Subtraction of power-line harmonics from geophysics records: Geophysics, 58, 898–903.

Chavent, G., 2009, Nonlinear least squares for inverse problems, Scientific Computation: Theoretical foundations and step-by-step guide for applications: Springer, New York.

Costabel, S., and Müller-Petke, M., 2014, Despiking of magnetic resonance signals in time and wavelet domain: Near Surface Geophysics, 12, 185 – 197.

Dalgaard, E., Auken, E., and Larsen, J., 2012, Adaptive noise cancelling of multichannel magnetic resonance sounding signals: Geophysical Journal International, 191, 88–100.

Fisher, R. A., 1922, On the mathematical foundations of theoretical statistics: Philosophical Transactions of the Royal Society, A. 222, 309–368.

Ghanati, R., Fallahsafari, M., and Hafizi, M. K., 2014, Joint application of a statistical optimization process and Empirical Mode Decomposition to Magnetic Resonance Sounding Noise Cancellation: Journal of Applied Geophysics, 111, 110-120.

Ghanati, R., Fallahsafari, M., 2015, Comment on: Time-based noise removal from magnetic resonance sounding signals' by M. Shahi, H. Khaloozadeh and M. K. Hafizi: International journal of innovative computing, information and control, 11(1), 387–390.

Ghanati, R., Hafizi, M. K., and Fallahsafari, M., 2016a, Surface nuclear magnetic resonance signals recovery by integration of a non-linear decomposition method with statistical analysis: Geophysical Prospecting, 64, 489–504.

Ghanati, R., Hafizi, M. K., Mahmoudvand, R., and Fallahsafari, M., 2016b, Filtering and parameter estimation of surface-NMR data using singular spectrum analysis: Journal of Applied Geophysics, 130, 118-130.

Kay, S. M., 1993, Fundamentals of statistical signal processing, Estimation theory: Prentice-Hall.

Larsen, J. J., Dalgaard, E., and Auken, E., 2014, Noise cancelling of MRS signals combining model-based removal of power-line harmonics and multi-channel Wiener filtering: Geophysical Journal International, 196, 2, 828-836.

Legchenko, A., and Valla, P., 2003, Removal of power-line harmonics from proton magnetic resonance measurements: Journal of Applied Geophysics, 53, 103-120.

Müller-Petke, M., and Costabel, S., 2014, Comparison and optimal parameter setting of reference-based harmonic noise cancellation in time and frequency domain for surface-NMR: Near Surface Geophysics, 12, 199 – 210.

Müller-Petke, M., Dlugosch, R., and Yaramanci, U., 2011, Evaluation of surface nuclear magnetic resonance-estimated subsurface water content: New Journal of Physics, 13.

Neyer, F. M., 2010, Processing of full time series, multichannel surface-NMR signals: M. Sc. thesis, ETH Zurich.

Nyman, D. C., and Gaiser, J. E., 1983, Adaptive rejection of high-line contamination: 53rd Annual International Meeting, SEG, Expanded Abstracts, 321–323.

Saucier, A., Marchant, M., and Chouteau, M., 2006, A fast and accurate frequency estimation method for canceling harmonic noise in geophysical records: Geophysics, 71, V7-V18.

Walsh, D. O., 2008, Multi-channel surface NMR instrumentation and soft-ware for 1D/2D groundwater investigations: Journal of Applied Geophysics, 66, 140–150.