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Volume 8 Number 1
  • ISSN: 1569-4445
  • E-ISSN: 1873-0604

Abstract

ABSTRACT

We present a fast approximate method for 1D inversion of frequency domain data and apply it to frequency domain helicopter‐borne data from the Bookpurnong area of the Murray River, South Australia. The method is based on fast approximate forward computation of transient electromagnetic step responses and their derivatives with respect to the model parameters of a 1D model, with the frequency domain responses and derivatives then found through Fourier transformation of the time‐domain counterparts. The inversion is carried out with multi‐layer models in an iterative, constrained least‐squares inversion scheme including explicit formulation of the model regularization through a model covariance matrix. The method is 30 times faster than conventional full inversion for a layered earth model and produces model sections of concatenated 1D models and contoured maps of mean conductivity in elevation intervals almost indistinguishable from those of a conventional full inversion. In a theoretical forward and inverse modelling study, the fast approximate and conventional computation methods are compared demonstrating the applicability of the approximate method and its limitations.

Applied to the Bookpurnong RESOLVE® FDHEM data set from South Australia, the inversion produces model sections and conductivity maps that reveal the distribution of conductivity in the area and thereby the distribution of salinity. This information is crucial for any remediation effort aimed at alleviating the salinization of the river and the degradation of floodplain vegetation and associated ecosystems.

© European Association of Geoscientists and Engineers © 2010 European Association of Geoscientists and Engineers
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2009-05-01
2024-04-26

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References

  1. AukenE.1995. 1D time domain electromagnetic interpretations over 2D and 3D structures. Proceedings of the Symposium on the Application of Geophysics to Engineering and Environmental Problems, Orlando, USA, pp. 329–338. EEGS.
     [Google Scholar]
  2. AukenE. and ChristiansenA.V.2004. Layered and laterally constrained 2D inversion of resistivity data. Geophysics69, 752–761.
     [Google Scholar]
  3. BrodieR., GreenA. and MundayT.2004. Calibration of RESOLVE airborne electromagnetic data – Riverland and East Tintinara, South Australia. CRCLEME Open File Report 173.
     [Google Scholar]
  4. BrodieR. and SambridgeM.2006. A holistic approach to inversion of frequency‐domain airborne EM data. Geophysics71, G301–G312.
     [Google Scholar]
  5. ChristensenN.B.1990. Optimized fast Hankel transform filters. Geophysical Prospecting38, 545–568.
     [Google Scholar]
  6. ChristensenN.B.2002. A generic 1‐D imaging method for transient electromagnetic data. Geophysics67, 438–447.
     [Google Scholar]
  7. ChristensenN.B., ReidJ.E. and HalkjærM.2009. Fast, laterally smooth inversion of airborne time domain electromagnetic data. Near Surface Geophysics7, 599–612.
     [Google Scholar]
  8. ChristensenN.B. and TølbøllR.J.2009. A lateral model parameter correlation procedure for 1D inverse modeling. Geophysical Prospecting57, 919–929. doi:10.1111/j.1365‐2478.2008.00756.x
     [Google Scholar]
  9. ConstableS.C., ParkerR.L. and ConstableC.G.1987. Occam’s inversion: A practical algorithm for generating smooth models from electromagnetic sounding data. Geophysics52, 289–300.
     [Google Scholar]
  10. EllisR.G.1998. Inversion of airborne electromagnetic data. Exploration Geophysics29, 121–127.
     [Google Scholar]
  11. FarquharsonC.G., OldenburgD.W. and RouthP.S.2003. Simultaneous 1D inversion of loop‐loop electromagnetic data for both magnetic susceptibility and electrical conductivity. Geophysics68, 1857–1869.
     [Google Scholar]
  12. Fugro Airborne Surveys
    Fugro Airborne Surveys2005. RESOLVE® survey for CSIRO Exploration and Mining Southern Australia.Report # 05050.
     [Google Scholar]
  13. FullagarP.K. and ReidJ.E.2001. Emax conductivity depth transformation of airborne TEM data.15th ASEG meeting, Brisbane, Australia, Expanded Abstracts.
     [Google Scholar]
  14. HördtA. and SchollC.2004. The effect of local distortions on time‐domain electromagnetic measurements. Geophysics68, 87–96.
     [Google Scholar]
  15. HuangH. and FraserD.C.1996. The differential parameter method for multifrequency airborne resistivity mapping. Geophysics61, 100–109.
     [Google Scholar]
  16. HunterD. and MacnaeJ.2001. Subsurface conductivity structure as approximated by conductivity depth transforms.15th ASEG meeting, Brisbane, Australia, Expanded Abstracts.
     [Google Scholar]
  17. InmanJ.R.Jr, RyuJ. and WardS.H.1975. Resistivity inversion. Geophysics38, 1088–1108.
     [Google Scholar]
  18. LiY. and OldenburgD.W.1992. Approximate inverse mappings in dc resistivity problems. Geophysical Journal International109, 343–362.
     [Google Scholar]
  19. MacnaeJ., KingA., StolzE., OsmakoffA. and BlahaA.1998. Fast AEM data processing and inversion. Exploration Geophysics29, 163–169.
     [Google Scholar]
  20. MenkeW.1989. Geophysical Data Analysis: Discrete Inverse Theory.Academic Press.
     [Google Scholar]
  21. OldenburgD.W. and EllisR.G.1991. Inversion of geophysical data using an approximate inverse mapping. Geophysical Journal International105, 325–353.
     [Google Scholar]
  22. SattelD.2005. Inverting airborne electromagnetic (AEM) data with Zohdy’s method. Geophysics70, G77–G85.
     [Google Scholar]
  23. SerbanD.Z. and JacobsenB.H.2001. The use of broadband prior covariance for inverse palaeoclimate estimation. Geophysical Journal International147, 29–40.
     [Google Scholar]
  24. SengpielK.‐P.1988. Approximate inversion of airborne EM data from a multilayered ground. Geophysical Prospecting36, 446–459.
     [Google Scholar]
  25. SengpielK.‐P. and SiemonB.2000. Advanced inversion methods for AEM exploration. Geophysics65, 1983–1992.
     [Google Scholar]
  26. TølbøllR.J. and ChristensenN.B.2007. The sensitivity functions of frequency‐domain magnetic dipole‐dipole systems. Geophysics72, F45–F56.
     [Google Scholar]
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Fast approximate 1D inversion of frequency domain electromagnetic data
Near Surface Geophysics 8, 1 (2010); https://doi.org/10.3997/1873-0604.2009026
/content/journals/10.3997/1873-0604.2009026
/content/journals/10.3997/1873-0604.2009026
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