Effect of Positional Inaccuracies on Multielectrode Results

We have started to investigate the consequences of various noises o the interpreted results for various multielectrode arrays. We expect, it will be possible to find out, what kinds of noise have the most effect on the resulting data. Such an investigation may lead to a better elimination of potential errors due to noises. In the first step (presented in this paper) we studied the appearance of false anomalies due to positioning errors of the electrodes. In realistic field conditions, in spite of the greatest possible care, the electrode positions contain some inaccuracy: either in case of dense undergrowth, or varied topography, or very rocky field. In all these cases, it is not possible to put the electrodes in their theoretical position. As a consequence, the position data will contain some error. The extent of such inaccuracies was exactly determined by using a laser distance meter. Then, we computed their effect on the resulting apparent- and inverted resistivity data. We carried out such a study for Wenner, Wenner-beta, pole-dipole and pole-pole arrays. In the light of our conclusions, the usual assumption about random noise seems to be an oversimplification.