1887

Abstract

Summary

As an effective and convenience geophysics tool, the advantage of airborne EM becomes especially obvious for explorations in ridged terrain areas. However, AEM modelling has been ignoring the topographic effect. To understand the influence of topography on AEM, we develop in this paper a time-domain AEM modelling method based on unstructured finite-element method. First, Fourier transform is applied to Maxwell equations to transform the 2.5D problem to 2D. After obtaining the governing equations from the Maxwell equations, the Galerkin method is applied and we get the final discrete equations system for the solution of EM responses in frequency-domain. Via a cosine transform, we get the time-domain Airborne EM responses. The simulation results in this paper are compared with both the published results and the semi-analytical ones and proved that the algorithm presented in this paper has a high accuracy.

Loading

Article metrics loading...

/content/papers/10.3997/2214-4609.20142065
2014-09-08
2024-03-29
Loading full text...

Full text loading...

References

  1. Baba, K. and Seama, N.
    [2002] A new technique for the incorporation of seafloor topography in electromagnetic modelling. Geophysical Journal International, 150, 392–402.
    [Google Scholar]
  2. Liu, G. and Becker, A.
    [1992] Evaluation of terrain effect in AEM surveys using the boundary element method. Geophysics, 57, 272–278.
    [Google Scholar]
  3. Mitsuhata, Y.
    [2000] 2-D electromagnetic modeling by finite-element method with a dipole source and topography. Geophysics, 65, 465–475.
    [Google Scholar]
  4. Nam, M.J., Kim, H.J., Song, Y., Lee, T.J. and Son, J.S.
    [2007] 3D magnetotelluric modelling including surface topography. Geophysical Prospecting, 55, 277–287.
    [Google Scholar]
  5. Newman, G.A. and Alumbaugh, D.L.
    [1995] Frequency-domain modelling of airborne electromagnetic responses using staggered finite differences. Geophysical Prospecting, 43, 1021–1042.
    [Google Scholar]
  6. Newman, G.A.
    [1998] Three-dimensional frequency-domain modeling of airborne electromagnetic responses. Exploration Geophysics, 29, 111–119.
    [Google Scholar]
  7. Sasaki, Y. and Nakazato, H.
    [2003] Topographic effects in frequency-domain helicopter-borne electromagnetics. Exploration Geophysics, 34, 24–28.
    [Google Scholar]
  8. Siemon, B., Auken, E. and Christiansen, A.V.
    [2009] Laterally constrained inversion of helicopter-borne frequency-domain electromagnetic data. Journal of Applied Geophysics, 67, 259–268.
    [Google Scholar]
  9. Vallee, M.A. and Smith, R.S.
    [2009] Inversion of airborne time-domain electromagnetic data to a 1D structure using lateral constraints. Near Surface Geophysics, 7, 63–71.
    [Google Scholar]
  10. Xu, S.Z.
    [1994] The finite-element method in geophysics. Beijing, Science Press.
    [Google Scholar]
  11. Yin, C. and Hodges, G.
    [2007] Simulated annealing for airborne EM inversion. Geophysics, 72, F189–F195.
    [Google Scholar]
  12. Yin, C., Huang, W. and Ben, F.
    [2013] The full-time electromagnetic modeling for time-domain electromagnetic systems. Chinese Journal of Geophysics, 56, 3153–3162.
    [Google Scholar]
http://instance.metastore.ingenta.com/content/papers/10.3997/2214-4609.20142065
Loading
/content/papers/10.3997/2214-4609.20142065
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