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Record W2031802166 · doi:10.1117/12.383624

<title>Application of self-correcting tomographic inversion to a borehole radar test survey</title>

2000· article· en· W2031802166 on OpenAlex

Why this work is in the frame

A frame that forgets how it found something cannot be audited. These are the routes that admitted this work.

affAt least one author lists a Canadian institution in the pinned OpenAlex snapshot.

Bibliographic record

VenueProceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE · 2000
Typearticle
Languageen
FieldEngineering
TopicGeophysical Methods and Applications
Canadian institutionsPolytechnique Montréal
Fundersnot available
KeywordsTransmitterAttenuationTomographyGeologyRadarInversion (geology)BoreholeAmplitudeAcousticsComputer sciencePhysicsTelecommunicationsOpticsSeismology

Abstract

fetched live from OpenAlex

Variations of transmitter power and instrumental time drift often observed during borehole radar surveys are not usually monitored by the commercially-available acquisition systems. These variations may create artifacts in tomograms and lead to erroneous interpretation if not taken into account. The Self- Correcting Tomographic Inversion (SCTI) is a technique that jointly recovers these source variations together with the velocity or attenuation distribution. It assumes that the transmitting time T<SUB>o</SUB> and the 'source strength' A<SUB>o</SUB> may be considered constant only at each transmitter position. The problem results in a linear system of equations where the usual Jacobian matrix should be augmented by sparse columns with non-null elements corresponding to the respective transmitter positions only; thus the parameter vector (slowness or attenuation coefficient distribution) can be appended with the t<SUB>o</SUB> (or log A<SUB>o</SUB>) values for these transmitter positions. Synthetic and survey data examples demonstrate that the conventional inversion algorithm produces artifacts mainly located along the transmitter and the receiver boreholes and towards the corners of the tomogram. The magnitude of the artifacts depends on the distance between transmitter and receiver boreholes. The SCTI technique reduces the amplitude of these artifacts while recovering the transmitter drift. Two crosshole surveys with inter-changed transmitter-receiver positions were also performed to evaluate reciprocity. The resulted tomograms are slightly different, but the overall images seem to be improved. However, the SCTI seem to diminish the discrepancy between the reciprocal values. Meanwhile, the SCTI also recovers a very suitable variation for the transmitter parameters. We have also attempted to monitor the drift of these transmitter parameters by control measurements at the ground surface at different times during the survey with different antenna separations. It shows that the variation of t<SUB>o</SUB> and A<SUB>o</SUB> is of the same order as resulted from the SCTI method.

Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.

Full frame distilled prediction

Teacher imitation

Not calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.

metaresearch head score (Codex)0.000
metaresearch head score (Gemma)0.000
Version: codex-gemma-dda1882f352aValidation status: machine_predicted_unvalidated
Candidate categoriesnone
Consensus categoriesnone
DomainCandidate signal: none · Consensus signal: none
Study designCandidate signal: Bench or experimental · Consensus signal: Bench or experimental
GenreCandidate signal: Empirical · Consensus signal: Empirical
Teacher disagreement score0.484
Threshold uncertainty score0.583

Codex and Gemma teacher scores by category

CategoryCodexGemma
Metaresearch0.0000.000
Meta-epidemiology (narrow)0.0000.000
Meta-epidemiology (broad)0.0000.000
Bibliometrics0.0000.000
Science and technology studies0.0000.000
Scholarly communication0.0000.000
Open science0.0000.000
Research integrity0.0000.000
Insufficient payload (model declined to judge)0.0000.000

Machine scores (provisional)

The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.

Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.

Opus teacher head0.009
GPT teacher head0.223
Teacher spread0.215 · how far apart the two teachers sit on this one work
Validation statusscore_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from it