1887

Abstract

Summary

We present a 2D inversion code for frequency-domain HEM data designed for inverting field scale surveys on normal desktop computers. The fundamental algorithm is a 2.5D algorithm with field separation into primary and secondary fields. Due to limited memory, as well as performance concerns, sectioning is introduced for splitting large surveys into smaller sections. Sectioning is only done when calculating the 2D forward and derivatives, and it is done with a sufficient overlap, such that vital 2D information is preserved. The algorithm uses a hybrid scheme which i) starts with 1D forward and inverse calculations, ii) then switches to 2D forward calculations and 1D derivatives, and iii) finally ends with full 2D calculations. The result of this is a code which produces results like a 2D code, but with a substantially shorter computational time.

Loading

Article metrics loading...

/content/papers/10.3997/2214-4609.201702148
2017-09-03
2024-04-20
Loading full text...

Full text loading...

References

  1. Auken, E. & ChristiansenA. V.
    [2004] Layered and laterally constrained 2D inversion of resistivity data. Geophysics, 69, 752–761.
    [Google Scholar]
  2. Auken, E., ChristiansenA. V., FiandacaG., SchamperC., BehroozmandA. A., BinleyA., NielsenE., EffersøF., ChristensenN. B., SørensenK. I., FogedN. & VignoliG.
    [2015] An overview of a highly versatile forward and stable inverse algorithm for airborne, ground-based and borehole electromagnetic and electric data. Exploration Geophysics, 2015, 223–235.
    [Google Scholar]
  3. Christiansen, A. V. & AukenE.
    [2004] Optimizing a layered and laterally constrained 2D inversion of resistivity data using Broyden’s update and 1D derivatives. Journal of Applied Geophysics, 56, 247–261.
    [Google Scholar]
  4. Christiansen, A. V., AukenE., KirkegaardC., SchamperC. & VignoliG.
    [2015] An efficient hybrid scheme for fast and accurate inversion of airborne transient electromagnetic data. Exploration Geophysics, 1–8.
    [Google Scholar]
  5. Mitsuhata, Y.
    [2000] 2-D electromagnetic modeling by finite-element method with a dipole source and topography. Geophysics, 65, 465–475.
    [Google Scholar]
  6. Stoyer, C. & GreenfieldR. J.
    [1976] Numerical solutions of the response of a two-dimensional earth to an oscillating magnetic dipole source. Geophysics, 41, 519–530.
    [Google Scholar]
  7. Vöge, M.
    [2010] ngi25em Version 4.0 User Documentation.
    [Google Scholar]
  8. Vöge, M., PfaffhuberA., AukenE., KirkegaardC., BoesenT., HendricksS. & HunkelerP..
    [2015] 2.5 D Inversion of Sea Ice Thickness from Helicopter EM Data. First European Airborne Electromagnetics Conference.
    [Google Scholar]
  9. Ward, S.H. & Ward, G.W.
    [1988] Hohmann. Electromagnetic theory for geophysical applications. Electromagnetic methods in applied geophysics. 131–311.
    [Google Scholar]
http://instance.metastore.ingenta.com/content/papers/10.3997/2214-4609.201702148
Loading
/content/papers/10.3997/2214-4609.201702148
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