Pattern drilling exploration: Optimum pattern types and hole spacings when searching for elliptical shaped targets

  • Lawrence J. Drew
Article
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Abstract

In this study the selection of the optimum type of drilling pattern to be used when exploring for elliptical shaped targets is examined. The rhombic pattern is optimal when the targets are known to have a preferred orientation. Situations can also be found where a rectangular pattern is as efficient as the rhombic pattern. A triangular or square drilling pattern should be used when the orientations of the targets are unknown. The way in which the optimum hole spacing varies as a function of (1) the cost of drilling, (2) the value of the targets, (3) the shape of the targets, (4) the target occurrence probabilities was determined for several examples. Bayes' rule was used to show how target occurrence probabilities can be revised within a multistage pattern drilling scheme.

Key words

pattern drilling optimum hole spacing search theory detection probability 
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Copyright information

© Plenum Publishing Corporation 1979

Authors and Affiliations

  • Lawrence J. Drew
    • 1
  1. 1.U.S. Geological SurveyRestonUSA

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