Three‐dimensional imaging of subsurface structures using resistivity data

Abstract

We have developed a three‐dimensional inverse scheme for carrying out DC resistivity surveys, incorporating complicated topography as well as arbitrary electrode arrays. The algorithm is based on the finite‐element approximation to the forward problem, so that the effect of topographic variation on the resistivity data is effectively evaluated and incorporated in the inversion. Furthermore, we have enhanced the resolving power of the inversion using the active constraint balancing method. Numerical verifications show that a correct earth image can be derived even when complicated topographic variation exists. By inverting the real field data acquired at a site for an underground sewage disposal plant, we obtained a reasonable image of the subsurface structures, which correlates well with the surface geology and drill log data.

3D Inversion of Automated Resistivity Profiling (ARP) Data

“…Th e inversion procedure is based on a smoothness constrained Gauss- Newton algorithm. Th e Active Constraint Balancing (ACB) method was also incorporated in the inversion in order to enhance the least-squares resolving power and stability (Yi et al, 2001). Th e values of 0.01 and 1 were used for the lower (λ min ) and the upper (λ max ) bounds of the Lagrange multiplier respectively.…”

Hydrocarbon Spill Site Characterization by Electrical Resistivity Tomography and Ground Penetrating Radar Methods - a Review

“…Wenner array is the most common array, it is usually employed where there is an equal interest in vertical and lateral resolution; in cases where lateral resolution is of greater interest dipole-dipole arrays have been employed [13,14]. In acquiring 2D apparent resistivity data, the lateral coverage must be reasonably greater than the expected width of the target of interest, there must also be a detectable variation in the electrical resistance of the target from the surrounding country rock.…”

Ground penetrating radar and electrical resistivity tomography for locating buried building foundations: A case study in the city centre of Thessaloniki, Greece

“…All measured ERT sections were inverted using DC2dPro (Kim, 2009), while a 3D resistivity model was constructed with DC3dPro (Yi et al, 2001). ERT data were collected on a grid and therefore, apart from the traditional 2D inversion, it was possible to perform 3D processing and presentation of results, which is closer to reality.…”