Stepped frequency seismic method with acquisition time optimization
Bibliographic record
Abstract
Vibroseis technology is a seismic method for geological exploration and it is often applied in the search for underground oil reservoirs. Current methods vibrate the earth with a swept frequency "chirp" signal and results are obtained through correlation. This paper proposes a new stepped frequency method that will produce similar results with increased resolution. Resolution is improved by compensating for dispersion and by using coherent detection to eliminate harmonic components caused by nonlinearities. In addition to the reflection magnitude, the new technique is able to measure reflection angle which might assist in determining the type of subsurface discontinuity. This proposed technique energizes the ground with sinusoids in the frequency range of 5 Hz to 150 Hz where frequency is incremented in discrete steps. The amplitude of the reflected signal that is in phase with the transmitted signal is then recorded for each individual frequency step. Fourier transformation of the recorded data then shows the locations of subsurface discontinuities. Stepped frequency measurements take much longer than the current swept frequency measurement and ideas for minimizing this time are discussed in the paper.
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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 | 0.000 | 0.001 |
| Meta-epidemiology (narrow) | 0.001 | 0.001 |
| Meta-epidemiology (broad) | 0.001 | 0.000 |
| Bibliometrics | 0.001 | 0.001 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.001 | 0.001 |
| Open science | 0.001 | 0.001 |
| Research integrity | 0.001 | 0.001 |
| Insufficient payload (model declined to judge) | 0.005 | 0.002 |
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".