Simulation of the Effect of Convecting Patches of Enhanced Electron Density on HF Over-the-Horizon Radars (OTHRs) in the Polar Regions
Bibliographic record
Abstract
High-frequency over-the-horizon radars (OTHR) provide an economical means to detect and track noncooperative air targets over large expanses of land and sea. Due to the dynamic nature of the ionosphere, an OTHR requires a frequency management system where the operating frequencies and launch angles (azimuth and elevation) change periodically to maintain constant target detection. Accurate electron density models are required for the purpose of improving OTHR performance and for system planning and design. This is particularly true in the polar regions where large-scale electron density structures taking the form of patches and arcs of enhanced electron density are the common features of the F-region ionosphere. These structures form tilted reflection surfaces for HF radiowaves and result in propagation well displaced from the great circle direction. The effects of patches on the ray paths have been simulated, and their impact on OTHR frequency management is illustrated.
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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) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.001 |
| Scholarly communication | 0.001 | 0.000 |
| Open science | 0.001 | 0.000 |
| Research integrity | 0.001 | 0.001 |
| Insufficient payload (model declined to judge) | 0.002 | 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".