Variations in point positioning accuracies for single frequency GPS users during solar maximum
Bibliographic record
Abstract
Les signaux du Systeme de positionnement global (GPS) sont refractes par l'ionosphere dispersive, entrainant des ecarts en portee qui dependent de la frequence des signaux et du contenu total en electrons ionospheriques (CTEI). Ces ecarts en portee se traduisent directement en une degradation des precisions du positionnement GPS. Avec le retrait de la disponibilite selective en mai 2000, les effets ionospheriques demeurent la plus grande source d'erreurs de positionnement par point unique pour les utilisateurs de frequences uniques, particulierement au cours de la periode actuelle de maximum de l'activite solaire. Dans cet article, on examine les variations dans le CTEI au cours du maximum de l'activite solaire. On etudie ensuite les restrictions associees aux precisions du positionnement par point unique vertical et horizontal pour les utilisateurs de frequences uniques du GPS, en mettant l'accent sur les applications de positionnement en temps reel. Les tendances a long terme sont etudiees a l'aide des donnees des stations de reference du GPS au Canada, aux Etats-Unis et au Perou. Les precisions du positionnement sont etablies en fonction de l'heure locale, de la latitude, de la saison, des tempetes et du cycle solaire.
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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 | 0.001 | 0.007 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.001 | 0.002 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.001 | 0.001 |
| Open science | 0.000 | 0.001 |
| Research integrity | 0.001 | 0.000 |
| Insufficient payload (model declined to judge) | 0.002 | 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".