What question did this study set out to answer?

To evaluate how data noise and inaccurate noise standard deviation estimates affect two-dimensional crosshole resistivity images generated by Occam's inversion.

April 1, 1996Geophysics

The effects of noise on Occam's inversion of resistivity tomography data

View Full Paper

Ask AI

Bookmark

Authors

DLDouglas LaBrecqueInstitute for Radiological Image Sciences MMMichela MilettoWorld Food Programme WDWilliam DailyLawrence Livermore National Security

Discussion

Member takes

Implication

Computational modeling reveals how inaccurate noise estimation degrades crosshole resistivity tomography images, suggesting that temporal noise variations can mimic subsurface geoelectrical changes.

Key Points

To evaluate how data noise and inaccurate noise standard deviation estimates affect two-dimensional crosshole resistivity images generated by Occam's inversion.
Implemented a 2-D Occam's inversion scheme coupled with a finite-element forward solver to generate smooth models matching a target Chi-squared statistic.
Evaluated the inversion algorithm using synthetic crosshole resistivity models under various noise levels and incorrect noise variance assumptions.
Tested performance on field data from Livermore, California, and time-lapse monitoring data from an enhanced oil recovery site.
Image resolution systematically declines with increasing data noise, and underdetermined systems converge to an asymptotic smooth model rather than the true geoelectrical profile.
Underestimating noise standard deviation prevents adequate data fitting and introduces rough artifacts, whereas overestimating noise causes excessive smoothing and severe resolution loss.
Time-varying noise during subsurface monitoring alters image resolution across datasets, which can be misidentified as physical geoelectrical shifts.

Cite This Study

LaBrecque et al. (1996) studied this question.

synapsesocial.com/papers/6a7089fdf44fa9f079de3414 https://doi.org/10.1190/1.1443980

View Full Paper

Ask AI

Bookmark

Implication

Computational modeling reveals how inaccurate noise estimation degrades crosshole resistivity tomography images, suggesting that temporal noise variations can mimic subsurface geoelectrical changes.

The effects of noise on Occam's inversion of resistivity tomography data

Discussion

Member takes

Implication

Key Points

Cite This Study

The effects of noise on Occam's inversion of resistivity tomography data

Discussion

Member takes

Implication

Key Points

Cite This Study

Also Consider

Also Consider