Full waveform inversion of blended surface-related multiple orders
Bibliographic record
Abstract
ABSTRACT Full-waveform inversion (FWI) is capable of handling various wave types, for example, primary reflections, direct waves, diving waves, and multiple reflections. However, FWI often encounters high nonlinearity when the starting velocity model significantly deviates from the true velocity, and the existence of multiples can further worsen this situation. As a result, the objective function may be trapped in a local minimum, causing the inversion process to fail to converge to the global minimum. Constructing an objective function by decomposing multiples into different controlled orders and performing the FWI on multiples with consecutive orders can expedite convergence. However, conducting the FWI using multiples in an order-by-order way may result in high computational cost. This study addressed this challenge by creating virtual sources and supergathers. These supergathers phase-encode many orders of multiples and integrate them into one for FWI, requiring only one FWI for all orders of multiples. By using such a random phase-encoding scheme, crosstalk artifacts arising from interferences between mismatched multiple orders in the source and receiver wavefields can be largely mitigated. The proposed method was validated through numerical experiments with a synthetic data set, as well as using marine field data from Madagascar. The results demonstrate that FWI using phase-encoded multiples significantly improves convergence while maintaining computational efficiency.
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How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot 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.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.000 | 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 teacher head, 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".