Volume 32 Number 2
  • E-ISSN: 1365-2478



For helicopter‐borne electromagnetic systems, the distance between the transmitting and the receiving coils is small compared with the altitude above ground. For this case, a major simplification can be made for the calculation of model curves. Some two‐layer curves for the interpretation of frequency measurements are presented.

A very simple procedure is demonstrated for the conversion of the relative secondary field into apparent resistivity and apparent distance for the mapping of airborne electromagnetic data. Furthermore, an approximation is described for the determination of the thickness and the resistivity of a layer lying on a perfectly conducting half‐space.


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  1. Eraser, D.1978, Resistivity mapping with an airborne multicoil electromagnetic system, Geophysics43, 144–172.
    [Google Scholar]
  2. Frischknecht, F. G.1967, Fields about on oscillating magnetic dipole over a two‐layer earth, and application to ground and airborne electromagnetic surveys, Quarterly of the Colorado School of Mines62 (1), Golden/Colorado, pp. 2–6, 111.
    [Google Scholar]
  3. Koefoed, O., Ghosh, D. P. and Polman, G. J.1972, Computation of type curves for electromagnetic depth sounding with a horizontal transmitting coil by means of a digital linear filter, Geophysical Prospecting20, 406–420.
    [Google Scholar]
  4. Love, C. H.1966, Abscissas and weights for Gaussian quadrature for N= 2 to 100, and N= 125, 150, 175, 200, National Bureau of Standards Monograph 98, US Government Printing Office, Washington , DC .
    [Google Scholar]
  5. Sengpiel, K. P.1983, Resistivity/depth mapping with airborne electromagnetic survey data, Geophysics48, 181–196.
    [Google Scholar]
  6. Sengpiel, K. P. and Meiser, P.1981, Locating the fresh water/salt water interface on Spie‐keroog Island by airborne EM resistivity/depth mapping, Geologisches Jahrbuch C 29, Hannover .
    [Google Scholar]
  • Article Type: Research Article
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