Electrical resistivity tomography

Summary

Electrical resistivity tomography is a method to image the electrical resistivity of the ground from many measurements with electrodes. The electrodes are usually placed at the surface or in boreholes. For each measurement, a current is injected through two electrodes and a voltage is measured between two others. The data are converted to apparent resistivities and then inverted for a two- or three-dimensional resistivity model. So it is a geophysical inversion closely related to the Calderón problem. It is widely used in hydrogeology, environmental and engineering studies and archaeology.