Evaluation of a Doppler sonar system for fisheries applications
Bibliographic record
Abstract
Abstract We report on tests of a general-purpose, coherent, Doppler sonar system undertaken to explore its capabilities when applied to detecting discrete fish targets. This 250-kHz, 30 kHz bandwidth instrument provides for phase coding of the transmit pulses and coherent sampling of successive acoustic returns. Towtank tests were used to determine the basic operating capabilities of the system. Under these ideal conditions a single-ping velocity accuracy of between 3 and 8 cm s−1 can be achieved approaching the theoretical limit for this instrument. Field trials were undertaken on the Fraser River in British Columbia near the Pacific Salmon Commission's field site, allowing comparisons with conventional fisheries sonar systems. While the long-term goal is to apply the Doppler sonar system in a larger-scale marine environment, the passage of migrating salmon provides an ideal test opportunity with fish of predictable and well defined swimming behaviour. Individual fish-swimming speed can be measured with an accuracy of between 5 and 10 cm s−1. By comparison, water velocity measurements made with the same instrument can only achieve a theoretical accuracy of 60 cm s−1.
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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 | 0.003 | 0.007 |
| Meta-epidemiology (narrow) | 0.001 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.001 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.001 | 0.001 |
| Open science | 0.001 | 0.000 |
| Research integrity | 0.001 | 0.000 |
| Insufficient payload (model declined to judge) | 0.003 | 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".