1887
Volume 69, Issue 6
  • E-ISSN: 1365-2478

Abstract

ABSTRACT

Early‐time measurements of time‐domain electromagnetics carry information of the near surface, and therefore, the interpretation of such measurements is important, particularly when utilizing small‐loop acquisition devices. However, these early‐time gates are often distorted by responses from the acquisition system itself, primarily caused by self‐transients associated with the transmission link composed of the transmitter and receiver loops and with the investigated medium electrical properties. Estimating all such potential couplings is crucial for interpreting early‐time measurements and gathering information on the near surface. In this study, a receptor loop made of 20 turns was built for this purpose. Field results and simulations were then compared, which shows how full‐wave finite‐difference method in the time‐domain simulations can be used to accurately calculate the impedance characteristics of time‐domain electromagnetics systems. All simulations were performed using finite‐difference time‐domain software based on a fully explicit three‐dimensional solver. First and second sets of simulations, respectively, were carried out in free space to compare the results to an alternate simulation method with equivalent lumped electrical circuits and on a homogeneous half‐space with varying electrical resistivities. The results were then used to improve the inversion of field data acquired on a test site in Garchy, France.

Loading

Article metrics loading...

/content/journals/10.1111/1365-2478.13102
2021-06-14
2024-04-29
Loading full text...

Full text loading...

References

  1. Auken, E., Foged, N., Larsen, J.J., Lassen, K.V.T., Maurya, P.K., Dath, S.M. and Eiskjær, T.T. (2018) TTEM—a towed transient electromagnetic system for detailed 3D imaging of the top 70 m of the subsurface. Geophysics, 84(1), 13–22.
    [Google Scholar]
  2. Chevalier, A., Rejiba, F., Schamper, C., Thiesson, J. & Hovhannissian, G.(2016) TEM Systems Design: Using Full Maxwell FDTD Modelling to Study the Transient Response of Custom‐madeTx and Rx Coils. AGU Fall Meeting, San Francisco (USA).
    [Google Scholar]
  3. Cosenza, P., Marmet, E., Rejiba, F., Jun Cui, Y., Tabbagh, A. and Charlery, Y. (2006) Correlations between geotechnical and electrical data: a case study at Garchy in France. Journal of Applied Geophysics, 60(3–4), 165–178.
    [Google Scholar]
  4. Courant, R., Friedrichs, K. and Lewy, H. (1967) On the partial difference equations of mathematical physics. IBM Journal of Research and Development, 11(2), 215–234.
    [Google Scholar]
  5. Dabas, M., Jolivet, A. and Tabbagh, A. (1992) Magnetic susceptibility and viscosity of soils in a weak time varying field. Geophysical Journal International, 108(1), 101–109.
    [Google Scholar]
  6. Effersø, F., Auken, E. and Ingvard Sorensen, K. (1999) Inversion of band‐limited TEM responses. Geophysical Prospecting, 47(4), 551–564.
    [Google Scholar]
  7. Everett, M.(2013) Near‐Surface Applied Geophysics. Cambridge: Cambridge University Press,
    [Google Scholar]
  8. Finco, C. (2019) Étude de l'impact simultané des propriétés électriques, diélectriques et magnétiques du sous‐sol sur la mesure géophysique par méthode électromagnétique inductive dans le domaine temporel (TDEM) [PhD Thesis]. Sorbonne Université.
  9. Finco, C., Pontoreau, C., Schamper, C., Massuel, S., Hovhannissian, G. and Rejiba, F. (2018) Time‐domain electromagnetic imaging of a clayey confining bed in a brackish environment: a case study in the Kairouan Plain Aquifer (Kelbia salt lake, Tunisia). Hydrological Processes, 32(26), 3954–3965.
    [Google Scholar]
  10. Flis, M.F., Newman, G.A. and Hohmann, G.W. (1989) Induced‐polarization effects in time‐domain electromagnetic measurements. Geophysics, 54(4), 514–523.
    [Google Scholar]
  11. Grant, F. S. & West, G. F.(1965) Interpretation theory in applied geophysics. New‐York: McGraw‐Hill,
    [Google Scholar]
  12. Guérin, R., Descloitres, M., Coudrain, A., Talbi, A. and Gallaire, R. (2001) Geophysical surveys for identifying saline groundwater in the semi‐arid region of the central Altiplano, Bolivia. Hydrological Processes, 15(17), 3287–3301.
    [Google Scholar]
  13. Kamenetsky, F. and Oelsner, C. (2000) Distortions of EM transients in coincident loops at short time‐delays. Geophysical Prospecting, 48(6), 983–993.
    [Google Scholar]
  14. Kamon, M., Tsuk, M.J. and White, J.K. (1994) FASTHENRY: a multipole‐accelerated 3‐D inductance extraction program. IEEE Transactions on Microwave Theory and Techniques, 42(9), 1750–1758.
    [Google Scholar]
  15. Kozhevnikov, N.O. (2009) Applying the transmission line theory to study ungrounded horizontal loop self‐transients. Russian Geology and Geophysics, 50(3), 222–233.
    [Google Scholar]
  16. Kozhevnikov, N.O. (2016) Current turn‐off in an ungrounded horizontal loop: experiment and theory. Russian Geology and Geophysics, 57(3), 498–505.
    [Google Scholar]
  17. Levitskaya, T.M. and Sternberg, B.K. (2019) Electrical Spectroscopy of Earth Materials. Elsevier.
    [Google Scholar]
  18. Loewer, M., Günther, T., Igel, J., Kruschwitz, S., Martin, T. and Wagner, N. (2017) Ultra‐broad‐band electrical spectroscopy of soils and sediments – a combined permittivity and conductivity model. Geophysical Journal International, 210(3), 1360–1373.
    [Google Scholar]
  19. Mouhri, A., Flipo, N., Rejiba, F., de Fouquet, C., Bodet, L., Kurtulus, B., et al. (2013) Designing a multi‐scale sampling system of stream–aquifer interfaces in a sedimentary basin. Journal of Hydrology, 504, 194–206.
    [Google Scholar]
  20. Nabors, K. and White, J. (1991) FastCap: a multipole accelerated 3‐D capacitance extraction program. IEEE Transactions on Computer‐Aided Design of Integrated Circuits and Systems, 10(11), 1447–1459.
    [Google Scholar]
  21. Nyboe, N.S. and Sørensen, K. (2012) Noise reduction in TEM: presenting a bandwidth‐ and sensitivity‐optimized parallel recording setup and methods for adaptive synchronous detection. Geophysics, 77(3), E203–E212.
    [Google Scholar]
  22. Paul, C.R. (2010) Inductance: Loop and Partial. Wiley.
    [Google Scholar]
  23. Schamper, C., Finco, C. and Rejiba, F. (2018) An open‐access Python interface for inversion, sensitivity and equivalence analysis of TDEM data. Symposium on the Application of Geophysics to Engineering and Environmental Problems 2018.
  24. Sullivan, D.M. (2013) Electromagnetic Simulation Using the FDTD Method. John Wiley & Sons.
    [Google Scholar]
  25. Taflove, A. and Hagness, S.C. (1995) Computational Electromagnetics: The Finite‐Difference Time‐Domain Method. Boston: Artech House.
    [Google Scholar]
  26. Taflove, A. and Hagness, S.C. (2005) Computational Electrodynamics: The Finite‐Difference Time‐Domain Method. Boston: Artech House.
    [Google Scholar]
  27. Terman, F.E. (1950) Radio Engineers’ Handbook. New York: McGraw‐Hill.
    [Google Scholar]
  28. Thiesson, J., Tabbagh, A. and Flageul, S. (2007) TDEM magnetic viscosity prospecting using a Slingram coil configuration. Near Surface Geophysics, 5(6), 363–374.
    [Google Scholar]
  29. Tumanski, S. (2007) Induction coil sensors – a review. Measurement Science and Technology, 18(3), R31–R46.
    [Google Scholar]
  30. Yee, K. (1966) Numerical solution of initial boundary value problems involving Maxwell's equations in isotropic media. IEEE Transactions on Antennas and Propagation, 14(3), 302–307.
    [Google Scholar]
http://instance.metastore.ingenta.com/content/journals/10.1111/1365-2478.13102
Loading
/content/journals/10.1111/1365-2478.13102
Loading

Data & Media loading...

  • Article Type: Research Article
Keyword(s): Data processing; Electromagnetics; Full‐wave modelling; Numerical study

Most Cited This Month Most Cited RSS feed

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