A model based on the sensitivity functions can predict the apparent conductivities that will be measured over a feature of interest (e.g., a golf-course green). The modeling exercise can help assess the potential effectiveness of EMI for a given application. Figure 21.3 shows the apparent conductivities that the H/P-1 would measure over a model golf-green that is composed of materials of given conductivity. The model contains a layer of 10 mS/m material, representing sand, over 50 mS/m material, which represents the native soil. The thickness of the sand layer is zero at stations 0 and 20, 0.3 m at stations 3 through 8 and 12 through 17, and 0.5 m at station 10.

Although the native soil extends to the surface at stations 0 and 20, the HCP apparent conductivity will be a fraction of a mS/m and the PRP apparent conductivity will be a few mS/m less than the native-soil value of 50. This results from the fact that when the H/P-1 rests on the ground, its arrays are about 5 cm above the FIGURE 21.3 ground due to their positioning in the instrument. green.

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