UNDERWATER ACOUSTIC COMMUNICATION CHANNEL CHARACTERIZATION AT LOW FREQUENCIES IN SHALLOW WATER
Bibliographic record
Abstract
The channel characteristics for sound propagating at 1100 Hz off Nova Scotia, Canada in winter conditions were measured at a shallow water station over Sable Bank.Experimental and model results for propagation loss and time spreading are compared at source-receiver separations out to 180 kilometers.Relatively little time spreading was observed which is consistent with propagation dominated by a small number of modes.The low propagation losses observed are attributed to low bottom losses.The data were gathered using mobile platforms.The observed frequency spreading (typically 0.25 Hz) is attributed to platform motion excited by motion of the sea surface.The applicable propagation parameters are used to predict the channel capacity of a Differential Quadrature Phase Shift Keying communication system operating in the same environment and using a vertical receiving array to provide modal decomposition (mode filtering).The issue of providing suf cient transmitter power to meet a speci c error rate speci cation is also addressed.
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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 | 0.000 |
| 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) | 0.001 | 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".