Optimization Of Ert Surveys

The objective of this project was to determine the optimum array and electrode configurations to<br>produce the best resolution in ERT surveys. In this experiment, we considered the effects of<br>surface electrodes on resolution and the effects of different arrays on resolution. Experiments<br>were conducted at the University of Arizona Maricopa Field station using two rectangular ERT<br>cells equipped with surface and borehole electrodes. Data were collected with five different<br>arrays; pole-pole with and without surface electrodes and dipole-dipole arrays with 3 different<br>dipole lengths were conducted between boreholes and surface electrodes. Data have been<br>analyzed and inverted to get 3-D images of resistivities within a block of four boreholes.<br>Resolution steadily improved with distance in dipole length. The pole-pole surveys show much<br>more detail at lower depths. When augmented with surface electrodes, the pole-pole surveys<br>showed clearer resolution of layers.