Ionospheric effects in VLBI measured with space-ground interferometer RadioAstron
Bibliographic record
Abstract
ABSTRACT We report on slow phase variations of the response of the space-ground radio interferometer RadioAstron during observations of pulsar B0329+54. The phase variations are due to the ionosphere and clearly distinguishable from effects of interstellar scintillation. Observations were made in a frequency range of 316–332 MHz with the 110-m Green Bank Telescope and the 10-m RadioAstron telescope in 1-h sessions on 2012 November 26, 27, 28, and 29 with progressively increasing baseline projections of about 60, 90, 180, and 240 thousand kilometres. Quasi-periodic phase variations of interferometric scintles were detected in two observing sessions with characteristic time-scales of 12 and 10 min and amplitudes of up to 6.9 radians. We attribute the variations to the influence of medium-scale Travelling Ionospheric Disturbances. The measured amplitude corresponds to variations in vertical total electron content in ionosphere of about $0.1\times 10^{16}\, \text{m}^{-2}$. Such variations would noticeably constrain the coherent integration time in VLBI studies of compact radio sources at low frequencies.
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How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.000 |
| 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 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 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 teacher head, 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".