1887
Volume 46 Number 5
  • E-ISSN: 1365-2478

Abstract

A guided wave along a borehole is often observed in borehole radar measurements. These guided waves deform the antenna pattern and can cause artefacts in radar measurements. A water‐filled borehole or a conducting logging cable can function as a waveguide for electromagnetic waves under some conditions. We describe the theoretical characteristics of such a guided wave in a borehole and compare them with our experiments. The measured signal discussed was obtained with a directional borehole radar. This radar uses a cylindrical conformal array antenna as receiver and is a model of a conducting structure in a borehole. The induced field around the borehole was compared with the theory. The most fundamental symmetrical and asymmetrical modes were TM and HE, and they were identified in the measured signals using time–frequency distribution analysis and by observation of the azimuthal field distribution of the magnetic field.

Loading

Article metrics loading...

/content/journals/10.1046/j.1365-2478.1998.00103.x
2006-08-09
2024-04-23
Loading full text...

Full text loading...

References

  1. ChoiH.WilliamsW.J.1989. Improved time–frequency representation of multicomponent signals using exponential kernels. IEEE Transactions on Acoustics, Speech, and Signal Processing37,862–871.
    [Google Scholar]
  2. CohenL.1989. Time–frequency distributions — a review. Proceedings of the IEEE77,941–981.
    [Google Scholar]
  3. DuboisJ.C.1995. Borehole radar experiment in limestone: analysis and data processing. First Break13,57–67.
    [Google Scholar]
  4. KingR.W.P.SmithG.1981. Antennae in Matter. MIT Press.
  5. KongJ.A.1990. Electromagnetic Wave Theory, 2nd edn. John Wiley & Sons, Inc.
  6. MoghaddarA.WaltonE.K.1993. Time‐frequency distribution analysis of scattering from waveguide cavities. IEEE Transactions on Antennae and Propagation41,677–680.
    [Google Scholar]
  7. SatoM.TanimotoT.1992. A shielded loop array antenna for a directional borehole radar. 4th International Conference on Ground Penetrating Radar. Geological Survey of Finland, Special Paper16,323–327.
    [Google Scholar]
  8. SatoM.ThierbachR.1991. Analysis of a borehole radar in cross‐hole mode. IEEE Transactions on Geoscience and Remote Sensing29,899–904.
    [Google Scholar]
  9. WrightD.L., WattsR.D.BramsoeE.1984. A short‐pulse electromagnetic transponder for hole‐to‐hole use. IEEE Transactions on Geoscience and Remote SensingGE‐22,720–725.
    [Google Scholar]
http://instance.metastore.ingenta.com/content/journals/10.1046/j.1365-2478.1998.00103.x
Loading
/content/journals/10.1046/j.1365-2478.1998.00103.x
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