Geology Reference
In-Depth Information
Figure 6.5
Signal contribution sections for (a) Wenner, (b) Schlumberger
and (c) dipole-dipole arrays. The contours show the relative contributions to
the signal from unit volumes of homogeneous ground. Dashed lines indicate
negative values. Reproduced by permission of Dr R. Barker.
array is often preferred for depth sounding. However, offset techniques (see
Section 6.4.3) allow excellent results to be obtained with the Wenner.
Near-surface effects may be large when a gradient or two-electrode array
is used for profiling, but they are also very local. Large numbers of readings
are collected, and smoothing filters can be applied.
