Volume 40 Number 2
  • E-ISSN: 1365-2478



The borehole radar system, RAMAC, developed within the framework of the International Stripa Project, can be used in three different measuring modes; single‐hole reflection, cross‐hole reflection and cross‐hole tomography. The reflection modes basically provide geometrical data on features located at some distance from the borehole. In addition the strength of the reflections indicate the contrast in electrical properties. Single‐hole reflection data are cylindrically symmetrical with respect to the borehole, which means that a unique fracture orientation cannot be obtained. A method has been devised where absolute orientation of fracture zones is obtained by combining single‐hole reflection data from adjacent holes. Similar methods for the analysis of cross‐hole reflection data have also been developed and found to be efficient. The radar operates in the frequency range 20‐‐60 MHz which gives a resolution of 1–3 m in crystalline rock. The investigation range obtained in the Stripa granite is approximately 100 m in the single‐hole mode and 200‐‐300 m in the cross‐hole mode.

Variations in the arrival time and amplitude of the direct wave between transmitter and receiver have been used for cross‐hole tomographic imaging to yield maps of radar velocity and attenuation. The cross‐hole measurement configuration coupled with tomographic inversion has less resolution than the reflection methods but provides better quantitative estimates of the values of measured properties.

The analysis of the radar data has provided a consistent description of the fracture zones at the Stripa Cross‐hole site in agreement with both geological and geophysical observations. Comparison of the radar results with seismic cross‐hole data showed excellent agreement with respect to shape and location of the fracture zones in space. Comparison with hydraulic data shows that the features identified by radar are of hydrogeological significance.


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  1. Annan, A.P. and Davis, J.L.1976. Impulse radar sounding in permafrost. Radio Science11, 383–394.
    [Google Scholar]
  2. Black, J., Holmes, D. and Brightman, M.1987. Crosshole investigations. Hydrogeological results and interpretation. Stripa Project TR 87‐‐18, SKB, Stockholm, Sweden.
  3. Bradley, J.A. and Wright, D.L.1987. Microprocessor‐based data‐aquisition system for a borehole radar. IEEE Transactions on Geoscience and Remote SensingGE‐25, 441–447.
    [Google Scholar]
  4. Carlsten, S., Magnusson, K.‐A. and Olsson, O.1985. Crosshole investigations. Description of the small scale site. Stripa Project IR 85–05, SKB, Stockholm, Sweden.
  5. Coon, J.B., Fowler, J.C. and Schafers, C.J.1981. Experimental uses of short pulse radar in coal seams. Geophysics46, 1163–1168.
    [Google Scholar]
  6. Cosma, C.1987. Crosshole investigations. Short and medium range seismic tomography. Stripa Project TR 87‐07, SKB, Stockholm, Sweden.
  7. Daily, W.1984. Underground oil‐shale retort monitoring using geotomography. Geophysics49, 1701–1707.
    [Google Scholar]
  8. Davis, J.L. and Annan, A.P.1989. Ground‐penetrating radar for high‐resolution mapping of soil and rock stratigraphy. Geophysical Prospecting37, 531–551.
    [Google Scholar]
  9. Dines, K.A. and Lytle, R.J.1979. Computerized geophysical tomography. Proceedings of the IEEE67, 1065–1073.
    [Google Scholar]
  10. Dyer, B. and Worthington, M.H.1988. Some sources of distortion in tomographic velocity images. Geophysical Prospecting36, 209–222.
    [Google Scholar]
  11. Evans, S.1963. Radio techniques for the measurement of ice thickness. Polar Record11, 406–410.
    [Google Scholar]
  12. Gustavsson, M., Ivansson, S., Morén, P. and Pihl, J.1986. Seismic borehole tomography: measurement system and field studies. Geophysics50, 969–988.
    [Google Scholar]
  13. Hülsenbeck, P.V.1926. Verfaren zur elektrishen Bodenforshung. German Pat. No. 489434.
  14. Ivansson, S.1984. Crosshole investigations. Tomography and its application to crosshole seismic measurements. Stripa Project IR 84‐08, SKB, Stockholm, Sweden.
  15. Ivansson, S.1986. Seismic borehole tomography – theory and computational methods. Proceedings of the IEEE74, 328–338.
    [Google Scholar]
  16. Laine, E.F.1987. Remote monitoring of the steam‐flood enhanced oil recovery process. Geophysics52, 1457–1465.
    [Google Scholar]
  17. Lytle, R.J., Laine, E.F., Lager, D.L. and Davis, D.T.1979. Cross‐borehole electromagnetic probing to locate high‐contrast anomalies. Geophysics44, 1667–1676.
    [Google Scholar]
  18. Morey, R.M.1974. Continuous sub‐surface profiling by impulse radar. Proceedings Conference on Subsurface Exploration for Underground Excavation and Heavy Construction (American Society of Civil Engineers) , pp. 213–232.
  19. Nickel, H., Sender, F., Thierbach, R. and Weichart, H.1983. Exploring the interior of salt domes from boreholes. Geophysical Prospecting31, 131–148.
    [Google Scholar]
  20. Nilsson, B.1983. A new borehole radar system. Proceedings KEGS symposium on Borehole geophysics: mining and geotechnical applications, Toronto, Canada , 400.
  21. Nolet, G.1987. Seismic Tomography. D. Reidel Pub. Co.
    [Google Scholar]
  22. Olsson, O., Black, J.H., Cosma, C. and Pihl, J.1987a. Crosshole investigations. Final report. Stripa Project TR 87‐16, SKB, Stockholm, Sweden.
  23. Olsson, O., Falk, L., Forslund, O., Lundmark, L. and Sandberg, E.1987b. Crosshole investigations. Results from borehole radar investigations. Stripa Project TR 87‐11, SKB, Stockholm, Sweden.
  24. Olsson, O., Sandberg, E. and Nilsson, B.1983. Crosshole investigations. The use of borehole radar for the detection of fracture zones in crystalline rock. Stripa Project IR 83‐06, SKB, Stockholm, Sweden.
  25. Peterson, J., Paulsson, B. and McEvilly, T.1985. Applications of algebraic reconstruction techniques to crosshole seismic data. Geophysics50, 1566–1580.
    [Google Scholar]
  26. Ramirez, A.L. and Daily, W.D.1987. Evaluation of alterant geophysical tomography in welded tuff. Journal of Geophysical Research92, 7843–7853.
    [Google Scholar]
  27. Rubin, L.A., Fowler, J.C. and Marino, G.G.1978. Borehole radar. Ensco Project 1114. Enso, Springfield, Virginia , U.S.A .
    [Google Scholar]
  28. Sherman, M.M.1983. The determination of cementation exponents using high frequency dielectric measurements. The Log Analyst24, November–December, 5–11.
    [Google Scholar]
  29. SKB (Swedish Nuclear Fuel and Waste Management Company)
    SKB (Swedish Nuclear Fuel and Waste Management Company) , 1983. Final storage of spent nuclear fuel; KBS‐3. SKB, Stockholm, Sweden.
  30. Thierbach, R.1974. Electromagnetic reflections in salt deposits. Journal of Geophysics40, 633–637.
    [Google Scholar]
  31. Ulriksen, C.P.F.1982. Application of impulse radar to civil engineering . Ph.D. thesis, Lund University of Technology, Sweden.
  32. Unterberger, R.R.1978. Radar propagation in rock salt. Geophysical Prospecting26, 312–328.
    [Google Scholar]
  33. Walford, M.1985. Exploration of temperate glaciers. Physics Bulletin36, 108–109.
    [Google Scholar]
  34. Wong, J., Hurley, P. and West, G.1983. Crosshole seismology and seismic imaging in crystalline rocks. Geophysics50, 686–689.
    [Google Scholar]
  35. Wright, D.L. and Watts, R.D.1982. A single‐hole, short‐pulse radar system. In: Geophysical investigations in connection with geological disposal of radioactive waste. OECD/NEA, Ottawa, Canada, 317.
  • Article Type: Research Article
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