Paper published in a journal (Scientific congresses and symposiums)
Image appraisal tools for electrical resistivity tomography
Caterina, David; Beaujean, Jean; Robert, Tanguy et al.
2011In Proceedings of SAGEEP, 24, p. 7
Peer reviewed
 

Files


Full Text
Caterina Sageep.ppt
Publisher postprint (24.45 MB)
Request a copy

All documents in ORBi are protected by a user license.

Send to



Details



Keywords :
Image appraisal; Electrical resistivity tomography; Geophysics
Abstract :
[en] Image appraisal is a problem frequently encountered in electrical resistivity tomography (ERT), and more generally in non-linear geophysical inversion. It may include several aspects such as the identification of the geometry of buried structures, the detection of numerical artefacts, the estimation of the depth of investigation or the exactitude of inverted parameters. Geophysicists can rely on several tools published in the literature to address these issues. However, few studies offer a quantitative comparison on the performance of these tools concerning the different mentioned aspects. Moreover, to our knowledge, there is no commonly accepted methodology to handle image appraisal. In this contribution, we compared quantitatively the ability of different image appraisal indicators to reach different objectives (geometry, artefacts, depth of investigation, parameter resolution). Among possible image appraisal tools, the model resolution matrix (MRM), the cumulative sensitivity matrix (CSM) and the depth of investigation index (DOI) are the most cited ones and were studied here. We compared them first on numerical models representing different geological situations. This numerical benchmark showed that indicators based on the MRM and CSM were the more appropriate to appraise ERT images in terms of the geometry of structures and the exactitude of inverted parameters, DOI providing mainly qualitative information. On this basis, we propose a methodology to appraise field ERT images focusing on the resolution and geometric aspects (others being implicitly studied). First, True Synthetic Models (TSM), representing simplified cases of field ERT images, are built using available information. Then, through forward modelling, synthetic ERT data are computed and inverted to provide the Inverted Synthetic Models (ISM). Afterwards, a comparison between TSM and ISM (or their gradients for geometry) is made in order to define the errors on inverted parameters. This discrepancy is then plotted with respect to resolution indicator values and points out in every tested cases a resolution range over which the errors abruptly increase allowing the definition of threshold values. The final step consists in applying the threshold values on the field ERT images and to validate the results with a posteriori knowledge.
Research center :
Université de Liège - Département ArGEnCo - GEO³ - Geophysique Appliquée
Disciplines :
Geological, petroleum & mining engineering
Author, co-author :
Caterina, David  ;  Université de Liège - ULiège > Département Argenco : Secteur GEO3 > Géophysique appliquée
Beaujean, Jean ;  Université de Liège - ULiège > Département Argenco : Secteur GEO3 > Géophysique appliquée
Robert, Tanguy ;  Université de Liège - ULiège > Département Argenco : Secteur GEO3 > Géophysique appliquée
Nguyen, Frédéric ;  Université de Liège - ULiège > Département Argenco : Secteur GEO3 > Géophysique appliquée
Language :
English
Title :
Image appraisal tools for electrical resistivity tomography
Alternative titles :
[fr] Outils d'analyse d'image pour tomographie électrique
Publication date :
2011
Event name :
Symposium on the Application of Geophysics to Engineering and Environmental Problems (SAGEEP)
Event organizer :
Environmental & Engineering Geophysical Society
Event place :
Charleston, United States
Event date :
du 10 avril au 14 avril 2011
Audience :
International
Journal title :
Proceedings of SAGEEP
ISSN :
1554-8015
Special issue title :
SAGEEP
Volume :
24
Pages :
7
Peer reviewed :
Peer reviewed
Name of the research project :
Étude et exploitation des mesures géophysiques associées aux contaminants et aux processus de décontamination par agents biochimiques dans un sous-sol hétérogène.
Funders :
FRIA - Fonds pour la Formation à la Recherche dans l'Industrie et dans l'Agriculture [BE]
Available on ORBi :
since 30 April 2011

Statistics


Number of views
230 (43 by ULiège)
Number of downloads
16 (7 by ULiège)

OpenCitations
 
1

Bibliography


Similar publications



Contact ORBi