New ERT Arrays to Increase the Depth of Detectability

Depth of investigation (DOI) has always been in the focus of geoelectric measurements. The DOI of the different DC arrays can be an important question, especially when the survey should be performed in built-up areas where space is limited. A lot of definitions exist about the DOI thanks to its significant role in geoelectric investigations. The authors of this study consider important the definition based on the detectability of small-size inhomogeneities. Thus, the so-called depths of detectability (DD) values were calculated of the different arrays. The newly investigated 11n arrays were compared with the traditional arrays and they gave consequently higher DD values than the pole-dipole and dipole axial arrays. This is very promising for the future, mainly because 11n arrays can get useful information in less time than the traditional ones. It is also conceivable that these arrays have better imaging properties, because the high DD value usually indicates this feature. A dyke and a square prism model was the inputs for the forward modelling, both having resistive and conductive variants.