Array optimisation for multichannel electrical resistivity tomography instruments
Wilkinson, P.B.; Ogilvy, R.D.; Chambers, J.E.; Kuras, O.. 2007 Array optimisation for multichannel electrical resistivity tomography instruments. Keyworth, British Geological Survey [Poster]Before downloading, please read NORA policies.
In recent years there has been considerable research into the selection of near-optimal arrays of electrode configurations that enhance the resolution of electrical resistivity tomography (ERT) images. Several algorithms have been developed that select resistivity measurements based on their contribution to the cumulative sensitivity of the array (Furman et al., 2004; Hennig and Weller, 2005) or its model resolution matrix (Stummer et al. , 2004; Wilkinson et al., 2006a; 2006b). Homogeneous subsurface resistivity distributions were assumed for these studies, although better results can be obtained using the same algorithms if the resistivity distribution is known a priori (Anthansiou, 2006). When compared to standard arrays, such as dipole-dipole or Wenner- Schlumberger, optimised arrays can substantially improve the resolution of the ERT image for the same number of measurements (Wilkinson et al., 2006b). The driver for researching array optimisation techniques has been the development of computer controlled ERT systems that can address arbitrary combinations of current and potential electrodes. Unfortunately all the published optimisation algorithms share a problem that is likely to impede their wider use: the arrays that they produce are inherently ‘single channel’ (SC). Since they do not take advantage of the multichannel (MC) capability of modern ERT instruments, the optimised arrays that they produce are rather inefficient to use compared to many standard arrays that are well suited to MC operation. However, we have developed a simple extension that constrains our previous algorithm to choose near-optimal configurations that also fit well into a MC measurement scheme. This extension could easily be adapted to work with the other optimisation schemes cited above.
|Item Type:||Other (Poster)|
|Programmes:||BGS Programmes > Electrical Tomography|
|Additional Keywords:||Array optimisation, resistivity, tomography, instrumentation|
|NORA Subject Terms:||Earth Sciences|
|Date made live:||23 Aug 2007 14:57|
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