Limitations in DGPS positioning accuracies at low latitudes during solar maximum
Bibliographic record
Abstract
While it is possible to mitigate the impact of ionospheric effects on Global Positioning System (GPS) positioning applications through differential techniques, residual errors may persist in regions of steep TEC gradients. An enhancement of absolute TEC and large‐scale gradients is observed at low latitudes near the equatorial anomaly. This effect is significant in the equinoctial months during periods of solar maximum. In this paper, differential GPS (DGPS) positioning accuracies in the anomaly region are investigated during the period of solar maximum 1999–2000, using as data the L1 pseudoranges. TEC gradients of 30 TECU per 100 km are observed during March 2000, with corresponding horizontal and vertical position errors of approximately 25–30 m (95% confidence level) for single baseline processing. Positioning accuracies are improved by a factor of 5 for a wide area DGPS approach.
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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 | 0.002 | 0.011 |
| 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 | 0.001 | 0.001 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.002 | 0.002 |
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".