Preliminary error budget analysis of the coronagraphic instrument metis for the solar orbiter ESA mission
Bibliographic record
Abstract
METIS, the Multi Element Telescope for Imaging and Spectroscopy, is the solar coronagraph foreseen for the ESA Solar Orbiter mission. METIS is conceived to image the solar corona from a near-Sun orbit in three different spectral bands: in the HeII EUV narrow band at 30.4 nm, in the HI UV narrow band at 121.6 nm, and in the polarized visible light band (590 – 650 nm). It also incorporates the capability of multi-slit spectroscopy of the corona in the UV/EUV range at different heliocentric heights. METIS is an externally occulted coronagraph which adopts an “inverted occulted” configuration. The Inverted external occulter (IEO) is a small circular aperture at the METIS entrance; the Sun-disk light is rejected by a spherical mirror M0 through the same aperture, while the coronal light is collected by two annular mirrors M1-M2 realizing a Gregorian telescope. To allocate the spectroscopic part, one portion of the M2 is covered by a grating (i.e. approximately 1/8 of the solar corona will not be imaged). This paper presents the error budget analysis for this new concept coronagraph configuration, which incorporates 3 different sub-channels: UV and EUV imaging sub-channel, in which the UV and EUV light paths have in common the detector and all of the optical elements but a filter, the polarimetric visible light sub-channel which, after the telescope optics, has a dedicated relay optics and a polarizing unit, and the spectroscopic sub-channel, which shares the filters and the detector with the UV-EUV imaging one, but includes a grating instead of the secondary mirror. The tolerance analysis of such an instrument is quite complex: in fact not only the optical performance for the 3 sub-channels has to be maintained simultaneously, but also the positions of M0 and of the occulters (IEO, internal occulter and Lyot stop), which guarantee the optimal disk light suppression, have to be taken into account as tolerancing parameters. In the aim of assuring the scientific requirements are optimally fulfilled for all the sub-channels, the preliminary results of manufacturing, alignment and stability tolerance analysis for the whole instrument will be described and discussed.
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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 | 0.003 | 0.009 |
| Meta-epidemiology (narrow) | 0.001 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.001 |
| Bibliometrics | 0.002 | 0.001 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.001 | 0.001 |
| Open science | 0.001 | 0.001 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.002 | 0.001 |
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".