Warm calibration unit of the mid-infrared ELT instrument METIS: overview and current status towards FDR
Bibliographic record
Abstract
The warm calibration unit (WCU) is one of the subsystems of the future METIS instrument on the Extremely Large Telescope (ELT). Operating at room temperature, the WCU is mounted above the main cryostat of METIS. It will be employed as a calibration reference for science observations, as well as for verification and alignment purposes during the AIT phase. The WCU is designed and constructed at the University of Cologne, one of the partner in the METIS consortium. WCU recently went through a successful Optics Long Lead Items Review by ESO. Now, the WCU is entering the last phase of the project, the Final Design Review (FDR). In this paper, we present the current status of the WCU design and summarize the mechanical and system engineering work. We describe the design of the hexapod formed by six manually adjustable links and its interfaces with the METIS cryostat together with the CFRP-based optical bench and Invar-based optical mounts. Lab prototyping results of one actuator under a nominal load of 5 kN confirms the achievable high linear resolution (20 µm). We present the status of the WCU laser cabinet. We discuss the lastest progress in the laboratory testing of some WCU functionalities, such as the fibre-fed monochromatic sources for the spectral calibration of the LM-Spectrograph of METIS, and the spatial calibration sources using the integrating sphere. We detail the activities foreseen until FDR together with the preparation of the sub-system MAIT work.
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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 | 0.011 | 0.004 |
| Meta-epidemiology (narrow) | 0.001 | 0.001 |
| Meta-epidemiology (broad) | 0.001 | 0.001 |
| Bibliometrics | 0.003 | 0.002 |
| Science and technology studies | 0.001 | 0.001 |
| Scholarly communication | 0.003 | 0.003 |
| Open science | 0.003 | 0.002 |
| Research integrity | 0.002 | 0.002 |
| Insufficient payload (model declined to judge) | 0.005 | 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".