1887
  1. Home
  2. A-Z Publications
  3. Near Surface Geophysics
  4. Volume 7, Issue 1
  5. Article
Volume 7 Number 1
  • ISSN: 1569-4445
  • E-ISSN: 1873-0604

Abstract

We invert time‐domain airborne electromagnetic data in such a way as to obtain a model that varies slowly along the profile. This is achieved by modifying a typical one‐dimensional inversion algorithm to include lateral constraints. The lateral constraints are included as a roughness matrix that is solved simultaneously with the Jacobian matrix in an iterative eigenparameter inversion. In this case, multiple soundings along a line are all solved simultaneously. The lateral constraints can be applied to the resistivities and the thicknesses, both separately and together. We apply these techniques in two situations where airborne geophysical data are applied to near‐surface exploration. The first case is in a resistive environment where we are interested in quantifying a superficial conductive overburden. In this case, lateral constraints improve the geological image compared with those images obtained using unconstrained layered‐earth inversion. In the second case, we want to map the thickness of a resistive aquifer covering a saline layer. In this case, we show how varying the weights on the lateral constraints can change the image of the thickness of the aquifer. The presence of numerous cultural artefacts makes the inversion problematic. Application of a first‐difference constraint did the best job at removing culture but resulted in oversmoothing of the hydrogeology. The use of a second‐difference lateral constraint gave a good rendition of the hydrogeology but did not suppress the culture as well as the first‐difference constraint.

© European Association of Geoscientists and Engineers © 2009 European Association of Geoscientists and Engineers
Loading

Article metrics loading...

/content/journals/10.3997/1873-0604.2008035
2008-11-01
2024-04-27

  • From This Site

    /content/journals/10.3997/1873-0604.2008035
    dcterms_title,dcterms_subject,pub_keyword
    -contentType:Journal -contentType:Contributor -contentType:Concept -contentType:Institution
    10
    5
Loading full text...

Full text loading...

References

  1. AnnanA.P. and LockwoodR.1991. An application of airborne GEOTEM in Australian conditions. Exploration Geophysics22, 5–12.
     [Google Scholar]
  2. AnnanA.P., SmithR.S., LemieuxJ., O’ConnellM.D. and PedersenR.N.1996. Resistive‐limit, time‐domain AEM apparent conductivity. Geophysics61, 93–99.
     [Google Scholar]
  3. AukenE. and ChristiansenA.V.2004. Layered and laterally constrained 2D inversion of resistivity data. Geophysics69, 752–761.
     [Google Scholar]
  4. AukenE., ChristiansenA.V., JacobsenB.H., FogedN. and SørensenK.I.2005b. Piecewise 1D laterally constrained inversion of resistivity data: Geophysical Prospecting53, 497–506. doi: 10.1111/j.1365‐2478.2005.00486.x
     [Google Scholar]
  5. AukenE., ChristiansenA.V., JacobsenL. and SoerensenK.2004. Laterally contrained 1D inversion of 3D TEM data. Near Surface 2004, Utrecht, the Netherlands, Expanded Abstracts.
     [Google Scholar]
  6. AukenE., ChristiansenA.V., JacobsenL. and SoerensenK.2005a. Laterally contrained 1D inversion of 3D TEM data. SAGEEP 2005, Atlanta, USA, Expanded Abstracts.
     [Google Scholar]
  7. AukenE., FogedN. and SørensenK.I.2002. Model recognition by 1‐D laterally constrained inversion of resistivity data. Proceeding of the 9th Meeting of the Environmental and Engineering Geophysical Society‐European Section, pp. 241–244.
     [Google Scholar]
  8. AukenE., FogedN., WestergaardJ., ChristiansenA.V. and SoerensenK.2006. Processing, inversion, and management of SkyTEM data for groundwater investigations. AEM Workshop Hannover 2006, Airborne EM – Recent Activities and Future Goals. Hannover, Germany.
     [Google Scholar]
  9. BrodieR. and SambridgeM.2006. A holistic approach to inversion of frequency‐domain airborne EM data. Geophysics71, G301–G312.
     [Google Scholar]
  10. ChenJ. and RaicheA.1998. Inverting AEM data using a damped eigenparameter method. Exploration Geophysics29, 128–132.
     [Google Scholar]
  11. ChristiansenA.V., AukenE., FogedN. and SoerensenK.2006. Spatially constrained inversion of area covering datasets. Near Surface 2006, Helsinki, Finland, Expanded Abstracts.
     [Google Scholar]
  12. ChristiansenA.V. and ChristensenN.B.2003. A quantitative appraisal of airborne and ground‐based transient electromagnetic (TEM) measurements in Denmark. Geophysics68, 523–534.
     [Google Scholar]
  13. JuppD.L.B. and VozoffK.1975. Stable iterative methods for the inversion of geophysical data. Geophysical Journal of the Royal Astronomical Society42, 957–976.
     [Google Scholar]
  14. Ontario Geological Survey
    Ontario Geological Survey . 2000. Airborne magnetic and electromagnetic surveys, Reid Mahaffy airborne geophysical test site survey. Ontario Geological Survey. Miscellaneous Release Data (MRD)‐55.
     [Google Scholar]
  15. PirttijärviM.T. and LerssiJ.2006. Laterally constrained 1D inversion of airborne electromagnetic data. Near Surface 2006, Helsinki, Finland, Expanded Abstracts.
     [Google Scholar]
  16. RaicheA.1998. Modelling the time‐domain response of AEM systems. Exploration Geophysics29, 103–106.
     [Google Scholar]
  17. ReidJ.E. and VrbancichJ.2004. A comparison of the inductive‐limit footprints of airborne electromagnetic configurations. Geophysics69, 1229–1239.
     [Google Scholar]
  18. SiemonB., AukenE. and ChristiansenA.V.2008. Laterally constrained inversion of frequency‐domain helicopter‐borne electromagnetic data. Journal of Applied Geophysics. doi:10.1016/j.jappgeo.2007.11.003.
     [Google Scholar]
  19. SmithR.S., O’ConnellM.D. and PoulsenL.H.2004. Using airborne electromagnetics surveys to investigate the hydrogeology of an area near Nyborg, Denmark. Near Surface Geophysics3, 123–130.
     [Google Scholar]
  20. TartarasE.2006. Laterally constrained inversion of fixed‐wing frequency‐domain AEM data. Near Surface 2006, Helsinki, Finland, Expanded Abstracts.
     [Google Scholar]
  21. WitherlyK., IrvineR. and GodboutM.2004. Reid Mahaffy Test Site, Ontario Canada: an example of benchmarking in airborne geophysics. 74th SEG meeting, Denver, Colorado, USA, Expanded Abstracts, 1202–1204.
     [Google Scholar]
http://instance.metastore.ingenta.com/content/journals/10.3997/1873-0604.2008035
Loading
Inversion of airborne time‐domain electromagnetic data to a 1D structure using lateral constraints
Near Surface Geophysics 7, 63 (2009); https://doi.org/10.3997/1873-0604.2008035
/content/journals/10.3997/1873-0604.2008035
/content/journals/10.3997/1873-0604.2008035
Loading

Data & Media loading...

  • Article Type: Research Article

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