Doppler sonar measurements of bedload sediment transport: Yes there’s a signal, but can it be quantified?
Bibliographic record
Abstract
It has been demonstrated that Doppler sonar measurements of apparent bottom velocity in rivers is correlated with bedload transport. We explore the degree to which this measurement can be quantified using a field deployable multi-frequency (1.2-2.2 MHz), bistatic Doppler sonar system that provides three-component velocity profiles over a ~30 cm interval with ~5 mm resolution at a rate of 50 profiles/sec. Model simulations of system performance demonstrate that the estimates of bed movement are proportional to sediment flux but scaling to actual sediment flux would require an empirical fit. In order to explore the system capability under actual field conditions, a series of experiments was undertaken at the St. Anthony Falls Laboratory (SAFL). The SAFL facility provides a 1.8 m deep, 2.75 m wide flume tank that allows flow rates of order 1 m/s over a mobile bed and where the bedload transport can be measured by sediment traps built into the flume system. We report on preliminary results from trials made at SAFL.
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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 | 0.002 | 0.006 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.000 |
| Bibliometrics | 0.001 | 0.001 |
| Science and technology studies | 0.000 | 0.001 |
| Scholarly communication | 0.001 | 0.002 |
| Open science | 0.001 | 0.000 |
| Research integrity | 0.001 | 0.001 |
| Insufficient payload (model declined to judge) | 0.001 | 0.001 |
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".