dispcraft¶
Physics-first, then hybrid physics+ML modeling of the Euclid/NISP grism spectral dispersion — from a geometrical-optics instrument model, through per-dataset and joint multi-dataset calibration against ground-test data, to an ML residual corrector and a field-dependent extension, benchmarked against a published reference result (arXiv:2506.08378).
This site is the published documentation for the project; the
repository itself carries the
full source, notebooks, and CLAUDE.md's stage-by-stage engineering log.
Project status: exploratory research, ongoing — not production-ready
This is a proof-of-concept pipeline, not a finished deliverable. The best model produced so far is still 1.7-8.4x worse than the reference paper's held-out accuracy (see Results below) — it does not yet reach the accuracy this instrument needs. See the Status Report §9-10 for open gaps and next steps.
Results at a glance¶
Final held-out accuracy (mean over the 6 RGS ground-test configs), compared
to the reference paper's own held-out (Argon) figure — full detail in
docs/Status_Report.md:
| Model | RMSE y (mm) | RMSE z (mm) |
|---|---|---|
| Physical model only (joint 3-tier fit) | 0.194 | 0.300 |
| Hybrid: physical + ML residual (recommended default) | 0.019 | 0.075 |
| Reference paper, held-out | 0.009 | 0.009 |
This does not yet reach the reference's accuracy (1.7x worse on y,
8.4x worse on z) — closing that gap is ongoing work, not a solved
problem. See docs/Status_Report.md §9-10 for the open items.
See the User Guide for how to reproduce and use this (and the BGS / 0th-order counterparts) yourself, or the Status Report for the full methodology and findings behind it.
Where to go next¶
- User Guide — install the project, load a calibrated model, and predict a spectrum's position — plus every notebook that produced this project's results.
- Status Report — the full write-up: methodology, every stage's findings, and the comparison against the reference paper.
- Beginner Introduction — the slide decks this project was built from, general optics and spectroscopy background, no prior knowledge assumed.
- Interactive Model — a live, in-browser visualization of the grism's optical model — drag the sliders, watch the spectral trace move.
- API Reference — full docstring-generated reference
for every
dispcraftmodule.
License¶
GNU Affero General Public License v3.0 — see LICENSE.