Classification and Basic Parameters of Geoelectric Arrays

All ever published surface geoelectric arrays (a large part of them are out of use, even completely forgotten) were collected and systematically investigated. This collection proved to be the basis of inter-comparisons. We revealed the original motivation of their design, as well. Then we produced parameter sensitivity maps for all possible arrays, by using a new analytical approach. Parameter sensitivity maps for non-linear and focussed arrays had never been presented before. Through examples we presented, how these maps can be applied. The so-called depth of investigation characteristics (DIC) was computed for all the arrays, where it exists, according to two different definitions. We carried out various comparisons, and revealed a complex relation among vertical resolution, depth of investigation and noise. We showed how the depth of investigation is constrained by the noise level. The maximal (theoretical) depths of investigation for 6 arrays were studied at various noise levels, as well. The general characterization of so many geoelectric arrays provides a better knowledge about them, and it will be hopefully useful also for other teams to select always the optimal arrays in their field problem.