Fade depth prediction on wireless microwave links using two-ray multipath model
Bibliographic record
Abstract
Fade depth prediction for airborne communication links is considered in this paper. There is no fading model for this specific scenario at the moment. The two closest models are the Olsen-Segal model for terrestrial links and the ITU-R model for satellite links. However, they cannot be directly applied to the airborne scenario. We propose a two-ray multipath fading model adapted to a realistic scenario of hilly or mountainous terrain, which applies to elevations angles higher than 2/spl deg/ and frequencies lower than 10 GHz, when the contribution of ground multipath component is dominant. It is interesting to note that the two-ray model predicts roughly the same fade depth dependence on the path clearance angle as the Olsen-Segal model, which may be considered as a theoretical justification, as to the best of our knowledge- for the first time, of the path elevation angle factor in that model. We further propose a hybrid approach to account for the atmospheric contribution to the total fade depth.
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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 | 0.002 |
| Meta-epidemiology (narrow) | 0.001 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.001 | 0.001 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.001 | 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 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".