Seeing Deeper by ERT Measurements

Depth of investigation is studied here, because nowadays more and more research should be carried out in built-up areas where space is limited, that is this question becomes more and more important. Since we think that the depth of investigation is basically determined by the detectability of small-size inhomogeneities, the so-called depth of detectability (DD) values, this parameter is investigated in this presentation for the 2D ERT. In the case of the studied prism and dyke models the not-yet investigated g11n arrays gave systematically higher DD values than the pole-dipole and dipole axial arrays which were the best conventional arrays from this point of view. This makes possible to obtain useful information even where the measuring area is limited, eg. in settlements, in less time and from greater depth. Moreover, due to the imaging properties of arrays having larger DD values are generally better it is easily possible that these arrays have also better imaging properties than those of the traditional arrays.