Instantaneous phase and the detection of lateral wavelet stability
Bibliographic record
Abstract
When it comes to the evaluation of stratigraphic plays, the issue of lateral wavelet stability ranks as an important concern. Interpreters accustomed to working complex structural plays may be inclined to relegate this type of concern to “background noise” status, but the reality is that when decisions to drill hinge on extremely subtle changes in waveform character (“when this front-loaded trough begins to show signs of splitting into a doublet, we've got porosity,” etc.), one cannot afford to be confusing geology with lateral changes in the embedded wavelet. In this short article we describe, and provide a mathematical justification for, a very simple technique which can help detect lateral changes in wavelet phase. The method entails first identifying a regionally stable and geologically “isolated” seismic event, then computing the instantaneous phase at the peak of the instantaneous amplitude (i.e., envelope) of the associated seismic waveform. Under certain restrictive conditions described below, the instantaneous phase evaluated at the peak of the instantaneous amplitude can be a good estimate of the wavelet phase.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.001 | 0.006 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.001 | 0.001 |
| Science and technology studies | 0.000 | 0.001 |
| Scholarly communication | 0.001 | 0.001 |
| Open science | 0.000 | 0.001 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.001 | 0.000 |
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.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".