Better than the Optimised Traditional ERT Array - The g11n Arrays

Abstract

A new array type - which was until now outside of the interest of the geophysicists - the g11n arrays will be introduced. These arrays belong to the so called quasi null arrays which are - according to their behaviour - between the traditional and the null arrays. It will be shown that these arrays can be more effective than the traditional arrays in detection and characterisation of anomalies have just a small impact on the potential (due to their small size, resistivity contrast to the host rock, and/or their large depth). In many investigations they proved to be even better than the Stummer array which was constructed by an optimisation procedure from the set of the traditional arrays. The g11n arrays proved to be moreover significantly better in horizontal and vertical resolution investigations than even the optimised array. It is already seen that the g11n arrays can be valuable tools for solution of many problems similar to the investigated ones, like e.g.: research of tunnels, caves, cables, abandoned river beds, or discontinuities in the clay layer below a waste deposit. The applications of these arrays shorten moreover the measuring time.