Noise and occam's inversion of resistivity tomography data

LaBrecque, Douglas; Owen, E. W.; Dailey, W.; Ramirez, Abelardo

doi:10.1190/1.1822100

Cited by 27 publications

(37 citation statements)

References 3 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…The &st and cost-effective electrical resistivity tomogr^hy (ERT) method has been widely used for threedimensional (3-D) in-situ monitoring (Daily and Ramirez, 1993;LaBrecque et aL, 1995;LaBrecque et aL, 1996a and1996b;LaBrecque et aL, 1998).…”

Section: Discussionmentioning

confidence: 99%

“…The electrical resistivity tomography (ERT) method is a promising 3-D characterization and monitoring technology for environmental applications (Daily and Ramroz, 1993;LaBrecque et aL, 1995;LaBrecque et al, 1996a and1996b;LaBrecque et aL, 1998).…”

Section: Introductionmentioning

confidence: 99%

“…First, our experience showed that ERT reciprocal measurements provided &irly accurate estimates of data standard deviation. Second, variance of ERT data may be obtained usingwhere Co is the i-th diagonal term of data covariance matrix; di is i-th data value; and A and B are the coefficients for the first two even terms of a Taylor's series about di (LaBrecque et aL, 1996b). A is usually given by a few percent of the smallest data value and may be around the hardware resohition.…”

mentioning

confidence: 99%

See 2 more Smart Citations

Stochastic Inversion of 3D ERT Data

Yang,

LaBrecque

1998

Symposium on the Application of Geophysics to Engineering and Environmental Problems 1998

View full text Add to dashboard Cite

This manuscript has been reproduced from the microfilm master. UMI films the text directly from the original or copy submitted. Thus, some thesis and dissertation copies are in typewriter face, while others may be from any type of computer printer.The quality of this reproduction is dependent upon the quality of the copy submitted. Broken or indistinct print, colored or poor quality illustrations and photographs, print bleedthrough, substandard margins, and improper alignment can adversely affect reproduction.In the unlikely event that the author dkl not send UMI a complete manuscript and there are missing pages, these will be noted. Also, if unauthorized copyright material had to be removed, a note will indicate the deletion. I hereby certify that I have read this dissertation prepared under my direction and recommend that it be accepted as fulfilling the dissertation requirement. Dissertati<@ Director Date STATEMENT BY AUTHORThis dissertation has been submitted in partial fiilfiUment of requirements for an advanced degree at The University of Arizona and is deposited in the University Library to be made available to borrowers under rules of the Library.Brief quotations from this dissertation are aUowable without special permission, provided that accurate acknowledgment of the source is made. Requests for permission for extended quotation from or reproduction of this manuscript in whole or in part may be granted by the head of the major department or the Dean of the Graduate College when in his or her judgment the proposed use of the material is in the interests of scholarship. In all other instances, however, permission must be obtained from the author. SIGNED:4 ACKNOWLEDGMENTS I am very grateful to Dr. Doug LaBrecque, my dissertation supervisor, for his guidance and mvahiable assistance. He walked me step by step from a graduate student to a professional geophysicist. What m^ressed me most is Doug's profound knowledge in all aspects of electrkal and electromagnetic geophysics. It is realty fortunate that I can proceed my career under his guklance for years to come.I am grateful to Dr. \fory Pouhon, my dissertation committee chair, who extended her warm heart and generous hands helping me out of an awkward situatioa I realty appreciate her time and patience in arrangements of try oral conq)rehensive exam and ond defense. It is a great loss that I did not learn enough from her about the unique neural networic technok)gy.Dr. Randall M. Richardson introduced me into the field of geophysical inversion in his Inverse Problems in Geophysics class. The thorough understanding of fundamental mverse problems I gained from 1^ class has proved efifective in solving this con^licated stochastic mverse problem. It is also worth mentioning that the numerical methods taught Dr. Shlomo P. Neuman in Hydrotogy department provided me with inq)lementation details and hands-on experiences m numerical algorithm development. From Dr. Jim Yeh I learned that a large group of hydrotogists have been attacking stochastk: inverse problems u...

show abstract

Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

mentioning

confidence: 99%

See 1 more Smart Citation

Stochastic Inversion of 3D ERT Data

Yang,

LaBrecque

1998

Symposium on the Application of Geophysics to Engineering and Environmental Problems 1998

View full text Add to dashboard Cite

show abstract

“…Error estimates that are too low result in a noisy model with inversion artifacts, while error estimates that are too high result in an overly smooth model with low resolving power (LaBrecque et al, 1996). The data weighting term in Equation 2.1, W d , is typically of the form diag(1/✏ 1 , ..., 1/✏ n ), in which ✏ i is the percent standard deviation associated with a stack of quadripole resistance measurements.…”

Section: Evaluating Errormentioning

confidence: 99%

Non-invasive flow path characterization in a mining-impacted wetland

Bethune

Randell

Runkel

et al. 2015

Journal of Contaminant Hydrology

View full text Add to dashboard Cite

Time-lapse electrical resistivity (ER) is used in this study to capture the annual pulse of acid mine drainage (AMD) contamination, the so-called 'first-flush' driven by spring snowmelt, through the subsurface of a wetland downgradient of the abandoned Pennsylvania Mine workings in Central Colorado. Data were collected from mid-July to late October of 2013, with an additional dataset collected in June of 2014. ER provides a distributed measurement of changes in subsurface electrical properties at high spatial resolution. Inversion of the data shows the development through time of multiple resistive anomalies in the subsurface, which corroborating data suggest are driven by changes in total dissolved solids (TDS) localized in preferential flow pathways. Because of the non-uniqueness inherent to deterministic inversion, the exact geometry and magnitude of the anomalies is unknown, but sensitivity analyses on synthetic data taken to mimic the site suggest that the anomalies would need to be at least several meters in diameter to be adequately resolved by the inversions. Preferential flow path existence would have a critical impact on the extent of attenuation mechanisms at the site, and their further characterization could be used to parameterize reactive transport models in developing quantitative predictions of remediation strategies.iii

show abstract

“…Les résistances de contact électrique entre les électrodes et le sol diminuent au cours du temps à partir de l'installation des électrodes, phénomène déjà constaté par d'autres auteurs (LABRECQUE et al, 1996). Ainsi les résultats présentés dans la suite concernent uniquement les temps t4 à t9, dont les résistances de contact restent comprises entre 2 et 12 kΩ (des résistances de prise inférieures à 20 kΩ sont généralement jugées très favorables à la qualité des mesures …”

Section: Diagnostic Et Prétraitement Des Mesuresunclassified