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Volume 47 Number 6
  • E-ISSN: 1365-2478

Abstract

We improve two aspects of the modelling scheme for the simulation of electromagnetic radio waves, based on the Fourier pseudospectral method.

When there are large contrasts in the material properties, use of the standard algorithm (regular grid) causes a series of artefacts, as, for instance, ringing and acausal events. These problems, due to the non‐locality of the differential operator, are solved by using the staggered Fourier method (staggered grid).

Realistic radiation patterns can be obtained from simple combinations of magnetic and electric sources. If the directivity pattern of the antenna is known, from either a finite‐difference simulation or an analytic evaluation or an experimental characterization, it can then be simulated by a composite‐source concept. This effective source is implemented in the modelling algorithm by means of a perturbation technique, which first computes the intensity and directional spectra of the single electromagnetic sources. Their location is optimized to obtain the best fit with a minimum number of sources. The approach is, in principle, valid for the far‐field radiation pattern of the antenna.

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2001-12-24
2024-04-27

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References

  1. AnnanA.P.1973. Radio interferometry depth sounding: Part I — theoretical discussion. Geophysics38,557580.
    [Google Scholar]
  2. ArconeS.A.1995. Numerical studies of the radiation patterns of resistivity loaded dipoles. Journal of Applied Geophysics33,3952.
    [Google Scholar]
  3. BergmannT.1998. Numerical modeling of high‐frequency electromagnetic wave propagation. PhD thesis, University of Kiel, Germany.
  4. BernabiniM., PettinelliE., PierdiccaN., PiroS., VersinoL.1995. Field experiments for characterization of GPR antenna and pulse propagation. Journal of Applied Geophysics33,6376.
    [Google Scholar]
  5. BourgeoisJ.M. & SmithG.S.1996. A fully three‐dimensional simulation of a ground‐penetrating radar. IEEE Transactions on Geoscience and Remote SensingGE‐34,3644.
    [Google Scholar]
  6. CarcioneJ.M.1996. Ground‐penetrating radar: Wave theory and numerical simulation in lossy anisotropic media. Geophysics61,16641677.
    [Google Scholar]
  7. CarcioneJ.M.1998. Radiation patterns for 2‐D GPR forward modeling. Geophysics63,424430.
    [Google Scholar]
  8. ChewW.C.1995. Waves and Fields in Inhomogeneous Media. Institute of Electrical and Electronics Engineers, Inc., New York.
  9. EnghetaN., PapasC.H., ElachiC.1982. Radiation patterns of interfacial dipole antennas. Radio Science17,15571566.
    [Google Scholar]
  10. FornbergB.1990. High‐order finite differences and pseudo‐spectral method on staggered grids. SIAM Journal of Numerical Analysis27,904918.
    [Google Scholar]
  11. HarringtonR.F.1968. Field Computation by Moment Methods. MacMillan Publishing Co.
  12. LandrøM., MittetR., SollieR.1993. Implementing measured source signatures in a coarse‐grid, finite‐difference modeling scheme. Geophysics59,18521860.
    [Google Scholar]
  13. MaloneyJ.G., SmithG.S., ScottW.R.1990. Accurate computation of the radiation from simple antennas using the finite‐difference time‐domain method. IEEE Transactions on Antennae and PropagationAP‐38,10591068.
    [Google Scholar]
  14. ÖzdenvarT. & McMechanG.1996. Causes and reduction of numerical artefacts in pseudo‐spectral wavefield extrapolation. Geophysical Journal International126,819828.
    [Google Scholar]
  15. ÖzdenvarT. & McMechanG.1997. Algorithms for staggered‐grid computations for poroelastic, elastic, acoustic, and scalar wave equations. Geophysical Prospecting45,403420.
    [Google Scholar]
  16. RobertsR.L. & DanielsJ.J.1997. Modeling near‐field GPR in three dimensions using the FDTD method. Geophysics62,11141126.
    [Google Scholar]
  17. SmithG.S.1984. Directive properties of antennas for transmission into a material half‐space. IEEE Transactions on Antennae and PropagationAP‐32,232246.
    [Google Scholar]
  18. TurnerG.1994. Modeling antenna–ground interactions. Proceedings of the 5th International Conference on Ground Penetrating Radar, Kitchener, Ontario, pp. 205221.
  19. WensinkW.A., GreeuwG., HofmanJ., Van DeenJ.K.1990. Measured underwater near‐field E‐patterns of a pulsed, horizontal dipole antenna in air: comparison with the theory of the continuous wave, infinitesimal electric dipole. Geophysical Prospecting38,805830.
    [Google Scholar]
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GPR modelling by the Fourier method: improvement of the algorithm [Link]
Geophysical Prospecting 47, 1015 (1999); https://doi.org/10.1046/j.1365-2478.1999.00151.x
/content/journals/10.1046/j.1365-2478.1999.00151.x
/content/journals/10.1046/j.1365-2478.1999.00151.x
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  • Article Type: Research Article

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