Removing Clock-Drift and Ionospheric Errors from the CHIME-KKO VLBI Delays
Bibliographic record
Abstract
The Canadian Hydrogen Intensity Mapping Experiment Fast Radio Burst project (CHIME/FRB) and its three outrigger telescopes will form a Very Long Baseline Interferometry (VLBI) network, with the goal of localising many hundreds of one-off and repeating FRBs to sub-arcsecond precision. Phase calibration is essential for successful VLBI, and requires removing errors due to ionosphere, clock, and instrumental delays. For calibrating the VLBI network, we plan to employ pulsars and traditional steady radio sources spread over the entire sky as calibrators. The first CHIME/FRB Outrigger, k'niʔatn k'l‿stk'masqt (KKO), came online in June 2022 and has been in commissioning ever since. It has a 66-km line of sight distance to CHIME and can provide a localisation accuracy of 1 arcsecond along the direction of the baseline. As the pathfinder for the outriggers, KKO has enabled the development and testing of our VLBI calibration techniques.
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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) | 0.001 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.002 | 0.002 |
| Science and technology studies | 0.001 | 0.000 |
| Scholarly communication | 0.002 | 0.001 |
| Open science | 0.001 | 0.002 |
| Research integrity | 0.001 | 0.001 |
| Insufficient payload (model declined to judge) | 0.004 | 0.003 |
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".