Dish Surface Characterisation for CHORD and HIRAX Using Metrology and Electromagnetic Simulations
Bibliographic record
Abstract
The Hydrogen Intensity and Real-time Analysis eXperiment (HIRAX) and the Canadian Hydrogen Observatory and Radio-transient Detector (CHORD) are next-generation radio interferometers designed to measure baryonic acoustic oscillations through 21-cm intensity mapping and also act as powerful platforms for studying fast radio bursts, pulsars, and cross-correlation studies. HIRAX and CHORD are being developed for deployment in the Karoo desert, South Africa, and the Dominion Radio Astrophysical Observatory (DRAO) in Kaleden, Canada, respectively, and operate in a drift-scan mode with manual adjustments in zenith angle within ±30° to build up sky coverage. HIRAX operates within a frequency range of 400–800 MHz, corresponding to a redshift range of 0.8 < <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$z$</tex> < 2.5, while CHORD covers a broader bandwidth from 300 to 1500 MHz, focusing on redshifts < 3.7. HIRAX and CHORD will consist of 256 and 512 elements, respectively, and both utilize six-meter diameter parabolic composite dishes with a focal ratio of f/0.21.
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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".