Magnetotelluric Power Line Noise Removal Using Temporally Varying Sinusoidal Subtraction of the Grid Utility Frequency
Tóm tắt
The magnetotelluric method relies on variations of natural electromagnetic fields, which in the vicinity of human settlements are persistently distorted by anthropogenic electromagnetic noise. A large source of noise to the magnetotelluric response is caused by the harmonic oscillations of the power network utility frequency centered on 50/60 Hz along with the associated higher harmonics. Removing this type of noise is essential for high frequency magnetotelluric measurements used for shallow surveys. There are a large number of approaches for how to treat power line noise in magnetotelluric signals, however, commonly used methods do not take into account time variations/instabilities of the utility frequency. That is not serious problem in vicinity of well balanced grid networks, but can cause issues in regions with larger utility frequency variations. Under such conditions, commonly used methods loose more of the natural signal, which is undesirable especially in case of very noisy datasets. Hence, we adopted approach for removing of power line noise with respect to time variations of the utility frequency and applied it to magnetotelluric signals to preserve more of natural signal. The method is based on modelling of the grid network harmonic oscillations by the optimum utility frequency and its integer multiples. The resulting sum of sinusoidal signals is subsequently subtracted from recorded data and only particular noise frequencies are removed from the original signal with high precision, while frequency ranges around power line harmonics are cleaned.
Tài liệu tham khảo
Arief, A., Nappu, M. B., & Sultan, A. (2020). Frequency stability and under frequency load shedding of the Southern Sulawesi power system with integration of wind power plants. IOP Conf. Series: Earth and Environmental Science. https://doi.org/10.1088/1755-1315/473/1/012105
Borah, U. K., Patro, P. K., & Suresh, V. (2015). Processing of noisy magnetotelluric time series from Koyna-Warna seismic region, India: A systematic approach. Annals of Geophysics, 58, 2. https://doi.org/10.4401/ag-6690
Butler, K. E., & Don Russel, R. (1993). Subtraction of power line harmonics from geophysical records. Geophysics, 58(6), 898–903.
Cagniard, L. (1953). Basic theory of the magneto-telluric method of geophysical prospecting. Geophysics, 18, 605–635. https://doi.org/10.1190/1.1437915
Campanyà, J., Ogaya, X., Jones, A. G., Rath, V., McConnell, B., Haughton, P. D. W., Ledo, J., Hogg, C., Blake, S., & Licciardi, A. (2019). Subsurface characterization of the Pennsylvanian Clare Basin, western Ireland, by means of joint interpretation of electromagnetic geophysical data and well-log data. Journal of Geophysical Research: Solid Earth, 124, 6200–6222. https://doi.org/10.1029/2018JB017074
Chave, D. A., & Jones, G. A. (2012). The magnetotelluric method: Theory and practice. Cambridge University Press.
Chave, A. D., & Thomson, D. J. (2004). Bounded influence magnetotelluric response function estimation. Geophysical Journal International, 157, 988–1006. https://doi.org/10.1111/j.1365-246X.2004.02203.x
Chawdhury, Md. A., & Chattopadhyay, D. (2018). A new beginning in frequency control for the Bangladesh power system. IEEE Power Engineering Society General Meeting. https://doi.org/10.1109/PESGM.2018.8586572
Chen, X. (2008) Filterung von geophysikalischen Zeitreihen mit periodisch auftretenden multifrequenten Störsignalen, Technische Universität Berlin, Diploma Thesis.
Chown, G.A., Wright, J.G., Van Heerden, R., Coker, M. (2018) System inertia and Rate of Change of Frequency (RoCoF) with increasing non-synchronous renewable energy penetration. Cigre Science&Engineering No. 11
Duong, Q.M., Tran, N., Sava, N.G., Leva, S., Musseta, M. (2018) The Impact of 150MWp PhoAn Solar Photovoltaic Project into Vietnamese QuangNgai - Grid. In: 10th International Conference and Exposition on Electrical and Power Engineering (EPE2018). Doi: https://doi.org/10.1109/ICEPE.2018.8559768
Egbert, G. D. (2002). Processing and interpretation of electromagnetic induction array data. Surveys in Geophysics, 23, 207–249. https://doi.org/10.1023/A:1015012821040
Egbert, G. D., & Booker, J. R. (1986). Robust estimation of geomagnetic transfer functions, Geophys. J.R. Astron. Soc., 87, 173–194. https://doi.org/10.1111/j.1365-246X.1986.tb04552.x
Fontes, S. L., Harinarayana, T., Dawes, G. J. K., & Hutton, V. R. S. (1988). Processing of noisy magnetotelluric data using digital filters and additional data selection criteria. Physics of the Earth and Planetary Interiors, 52, 30–40. https://doi.org/10.1016/0031-9201(88)90055-6
Friedrichs, B. (2004) Mapros, (Ver. 0.87b freeware), Metronix Measurement Instruments and Electronics Ltd. https://www.geo-metronix.de/mtxgeo/. Accessed 6 Nov 2017
Gamble, T., Gobau, W., & Clarke, J. (1979). Magnetotellurics with a remote reference. Geophysics, 44, 53–68. https://doi.org/10.1190/1.1440923
Hill, G. J., Bibby, H. M., Peacock, J., Wallin, E. L., Ogawa, Y., Carichi, L., Keys, H., Bennie, S. L., & Avran, Y. (2020). Temporal Magnetotellurics Reveals Mechanics of the 2012 Mount Tongariro, NZ. Eruption. Geophysical Research Letters, 47, e20190FL86429. https://doi.org/10.1029/2019GL086429
Hogg, C., Kiyan, D., Rath, V., Byrdina, S., Vandemeulebrouck, J., Revil, A., Viveiros, F., Carmo, R., Silva, C., & Ferreira, T. (2018). 3-D interpretation of short-period magnetotelluric data at Furnas Volcano, Azores Islands. Geophysical Journal International, 213, 371–386.
Hoover, D. B., Long, C. L., & Senterfit, R. M. (1978). Some results from audiomagnetotellurics investigations in geothermal areas. Geophysics, 43, 1501–1414. https://doi.org/10.1190/1.1440911
Jones, A. G., Chave, A. D., Auld, D., Bahr, K., & Egbert, G. (1989). A comparison of techniques for magnetotelluric response function estimation. Journal of Geophysical Research, 94(B10), 14201–14213. https://doi.org/10.1029/JB094iB10p14201
Kappler, K. N. (2012). A data variance technique for automated despiking of magnetotelluric data with a remote reference. Geophysical Prospecting, 60, 179–191. https://doi.org/10.1111/j.1365-2478.2011.00965.x
Kenya electricity grid code (2008) Energy Regulatory Commission, Nairobi, Kenya.
Krings, T. (2007) The Influence of Robust Statistics, Remote Reference, and Horizontal Magnetic Transfer Functions on Data Processing in Magnetotellurics. Master’s thesis, Universität Münster and GeoForschungs Zentrum Potsdam.
Kütter, S. (2015) Magnetotelluric Measurements Across the Southern Barberton Greenstone Belt, South Africa, PhD Thesis, University of Potsdam.
Lahti, I., Kontinen, A., & Nykänen, V. (2019). AMT survey in the Outokumpu ore belt, eastern Finland. Exploration Geophysics, 50(4), 351–363. https://doi.org/10.1080/08123985.2019.1606200
Larsen, J. J., Dalgaard, E., & Auken, E. (2014). Noise cancelling of MRS signals combining model-based removal of powerline harmonics and multichannel Wiener filtering. Geophysical Journal International, 196, 828–836. https://doi.org/10.1093/gji/ggt422
Lautze, N., Ito, G., Thomas, D., Frazer, N., Martel, S. J., Hinz, N., Tachera, D., Hill, G. J., Pierce, H. A., Wannamaker, P. E., & Martin, T. (2020). Play Fairway analysis of geothermal resources across the State of Hawai‘i: 4. Updates with new groundwater chemistry, subsurface stress analysis, and focused geophysical surveys. Geothermics. https://doi.org/10.1016/j.geothermics.2019.101798
Oettinger, G., Haak, V., & Larsen, J. C. (2001). Noise reduction in magnetotelluric time-series with a new signal–noise separation method and its application to a field experiment in the Saxonian Granulite Massif. Geophysical Journal International, 146, 659–669. https://doi.org/10.1046/j.1365-246X.2001.00473.x
Parkinson, W. D. (1962). The Influence of Continents and Oceans on Geomagnetic Variation. Geophysical Journal International, 6(4), 441–449. https://doi.org/10.1111/j.1365-246X.1962.tb02992.x
Pellerin, L., Alumbaugh, D., Reinemann, D. J., & Thompson, P. D. (2004). Power line induced current in the Earth determined by magnetotelluric techniques. Applied Engineering in Agriculture, 20, 703–706.
Robertson, K., Heinson, G., & Thiel, S. (2016). Lithospheric reworking at the Proterozoic-Phanerozoic transition of Australia imaged using AusLAMP Magnetotelluric data. Earth and Planetary Science Letters, 452, 27–35. https://doi.org/10.1016/j.epsl.2016.07.036
Szarka, L. (1988). Geophysical aspects of man made electromagnetic noise in the earth – a review. Surveys in Geophysics, 9, 287–318. https://doi.org/10.1007/BF01901627
Tikhonov, A. N. (1950). On determining electrical characteristics of the deep layers of the Earth’s crust. Doklady Akad, 73, 295–297.
Trad, D. O., & Travassos, J. M. (2000). Wavelet filtering of magnetotelluric data. Geophysics, 65, 482–491. https://doi.org/10.1190/1.1444742
Wannamaker, P., Caldwell, T., Jiracek, G. R., Maris, V., Hill, G. J., Ogawa, Y., Bibby, H. M., Bennie, S. L., & Heise, W. (2009). Fluid and deformation regime of an advancing subduction system at Marlborough, New Zealand. Nature, 460, 733–736. https://doi.org/10.1038/nature08204
Wannamaker, P., Hill, G., Stodt, J., Maris, V., Ogawa, Y., Selway, K., Boren, G., Bertrand, E., Uhlmann, D., Ayling, B., Green, A. M., & Fucht, D. (2017). Uplift of the central transantarctic mountains. Nature Communications, 8, 1–11. https://doi.org/10.1038/s41467-017-01577-2
Weckmann, U., Magunia, A., & Ritter, O. (2005). Effective noise separation for magnetotelluric single site data processing using a frequency domain selection scheme. Geophysical Journal International, 161, 635–652. https://doi.org/10.1111/j.1365-246X.2005.02621.x
Xu, Z., Tang, J., Li, G., Xin, H., Xu, Z., Tan, X., & Li, J. (2020). Groundwater resources survey of Tongchuan city using audio magnetotelluric method. Applied Geophysics, 17(5–6), 660–671. https://doi.org/10.1007/s11770-018-0709-2
Zimbabwe grid code. (2017). Supplement to the Zimbabwean Government Gazette, 11th August, 2017. Zimbabwe: Harare.