: Principles
This is an increasingly used geophysical survey technique in which vertical electrical resistivity sections are generated tomographically from measurements along a linear array of equally spaced electrodes inserted at the ground surface. The array is multiplexed to a resistivity meter which gathers one set of all possible independent apparent resistivity measurements. The software then uses complex processing algorithms to generate a geophysical section or profile. The closer the electrode spacing, the more detailed the image of the sub-surface can be generated, but at the expense of a lower penetration depth.
The Discovery Programme does not have the equipment to undertake this type of geophysical survey but it has been applied by geophysical specialists on selected projects.