Systems engineering efforts in the construction of the Canadian hydrogen observatory for radio-transient detectors
Bibliographic record
Abstract
The Canadian Hydrogen Observatory for Radio-transient Detectors (CHORD) will consist of 640 six-meter diameter antennas made of fiberglass composite material. The antennas will be fabricated and assembled at the Dominion Radio Astrophysical Observatory (DRAO) in Kaleden, BC, Canada, managed by the National Research Council of Canada (NRC). NRC has developed composite based single piece reflector technology over the past decade. A high degree of dimensional repeatability is key for CHORD to meet its scientific goals. This begins by manufacturing highly stable and repeatable dish molds. Subsequently, highly repeatable dishes are manufactured, components are assembled, and antennas are precisely positioned in the CHORD array. In this paper we present the antenna mechanical system, production of the antenna, top-level requirements, error definitions and verification plan, performance verification plan, and quality management plan. Since the antennas are made of composites, formulating an error budget is critical to keep track of the error allocations due to process induced errors, tooling and mold errors, and surface distortions due to gravity, wind and temperature variation. In addition, an overall pointing budget has been prepared to allocate the effect of mechanical misalignment, wind, foundation movement and other sources, etc. A Monte Carlo simulation of 1000 antennas provided the error stack up and expected precision values. A detailed verification plan is presented. Finally, the quality engineering plans are in place so that the manufacturing facility can ensure the production of the repeatable antennas through a quality assurance program. An acceptance sampling of the antennas will be conducted for metrology-based verification. A robust quality management plan is also in place to safeguard repeatability of the antenna production. The antennas will be accompanied by production data-cards, which enlist the critical configuration and process data about the antenna production and assembly operations. At the end of the pipeline, these antennas will go through verifications and acceptance tests to validate that performance requirements are met.
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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".