Final optical design of relay optics and alignment optics of the Warm Calibration Unit in METIS/ELT: analysis, performances, and the procurement of the optics
Bibliographic record
Abstract
METIS is a sophisticated mid-infrared imager and spectrograph covering wavelengths from 2.9 to 13.5 μm (astronomical L, M, and N bands), stands as one of the three primary science instruments at the Extremely Large Telescope (ELT). METIS will provide diffraction-limited imaging, coronagraphy, high-resolution integral field spectroscopy, and low/medium-resolution slit spectroscopy. Within the international METIS consortium, the University of Cologne is responsible for designing, manufacturing, integrating, and testing the Warm Calibration Unit (WCU). Among the other calibration functionalities, the WCU also facilitates alignment checks during Assembly, Integration, and Verification (AIT & AIV) through a visible light channel utilizing a CMOS camera, which can capture images of internal focal planes, pupil planes of the WCU, and various METIS sub-systems. This paper details the final optical design, preliminary opto-mechanical design, and analysis of alignment optics in the WCU. A laboratory test setup has been discussed, showcasing the estimation of SNR for the AIV mode of the WCU using an off-the-shelf CMOS camera and interating sphere. This paper also introduces the novel design concept of aluminum spherical mirrors employed in the main optical train of the WCU. We also present a brief overview of alignment verification procedures of the offner relay optics of the WCU sub-system. Furthermore, a detailed overview of the thermal analysis of the whole WCU will be discussed, which ensures the temperature difference between the WCU and the ELT dome will be within specified limits.
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
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 | 0.001 | 0.002 |
| Meta-epidemiology (narrow) | 0.001 | 0.001 |
| Meta-epidemiology (broad) | 0.001 | 0.001 |
| Bibliometrics | 0.001 | 0.000 |
| Science and technology studies | 0.001 | 0.001 |
| Scholarly communication | 0.002 | 0.001 |
| Open science | 0.001 | 0.001 |
| Research integrity | 0.001 | 0.001 |
| Insufficient payload (model declined to judge) | 0.004 | 0.002 |
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".