Two-dimensional individual and joint inversion of three- and four-electrode array dc resistivity data

In this paper, I suggest the use of combined inversion for three- and four-electrode array data. Two-dimensional (2D) inversion results calculated using Wenner ( W), Schlumberger ( S), Dipol-Dipol ( DD), left- and right-side pole-dipole ( PD-L and PD-R), synthetic data and their combined inversion results were compared with respect to the resolution and accuracy of the inverted models. This comparison showed that the combined inversion of data from any two sets of arrays ( e. g. W + S, W + DD, PD-L + DD) gave better resolution than the individual inversion of data from each array compared with the real model. However, inversion of the PD-L, PD-R and DD data sets jointly gave a better result than the single use of any electrode array and the combined inversion of any two electrode arrays. Furthermore, model resolution matrices obtained for all individual and combined data inversions showed that the combined data set inversion can recover the block resistivities at both the beginning and the end of the profile. Field data inversions also support the synthetic data inversion result.