ERT surveys have tended to use well-understood traditional electrode configurations to gather resistivity data. But ALERT permits the use of arbitrary arrangements of electrodes, and enables the collection of very large measurement sets that can cover extensive areas at high data density. Research is therefore ongoing into algorithms that can make use of this flexibility to maximise ERT image resolution.
Software has been developed that can automatically generate optimal electrode arrays for ERT 2D surveys (right). These optimised surveys make efficient use of multi-channel systems (e.g. ALERT) and have been tested using synthetic modelling studies, in the laboratory and in the field. They have been shown to provide better image resolution than traditional arrays of the same size (e.g. dipole-dipole).
More recent research in collaboration with Dr M.H. Loke of Geotomo Software has improved the efficiency of these routines by taking advantage of multi-core processors and graphics card acceleration. These advances should make 3D survey optimisation a reality in the near future.
Dr Paul Wilkinson
British Geological Survey
Tel: +44 (0)115 936 3086
Email: Dr Paul Wilkinson
Dr Jonathan Chambers
Team Leader - Geophysical Tomography
Tel: +44 (0)115 936 3428
Email: Dr Jonathan Chambers