opusreader2

SpectraSherpa bundles five unmodified real Bruker OPUS instrument files from the opusreader2 package-authored test corpus under MIT, used only as read-only parser conformance fixtures. The source is pinned to commit 96f970beb0ef92ccb3ee62fc3d8b7f27e1587c41.

• upstream project: https://github.com/spectral-cockpit/opusreader2
• license: MIT + file LICENSE (standard R-package convention); complete notice at THIRD_PARTY_LICENSES/opusreader2-MIT.txt
• authors: Philipp Baumann, Thomas Knecht, Pierre Roudier

Bundled fixture	Structural variant it exercises
617262_1TP_C-1_A5.0	Singular data/status pairing whose recorded MNY/MXY does not reproduce from the on-disk bytes -- an unambiguous pairing must not be refused for that reason
629266_1TP_A-1_C1.0	Two absorbance results sharing one OPUS type, disambiguated by decoded value against each candidate's MNY/MXY
BF_lo_01_soil_cal.1	Same duplicate-absorbance disambiguation; a Bruker ALPHA diffuse-reflectance soil measurement associated with Baumann et al. (2021), https://doi.org/10.5194/soil-7-717-2021
MMP_2107_Test1.001	Library-match and multi-channel result blocks outside this reader's documented scope, refused individually
test_spectra.0	A reflectance result outside this reader's documented scope, refused individually

Every file's decoded assets are cross-checked against an independently installed copy of brukeropus 1.4.3 -- the project this reader's own binary layout is adapted from (see brukeropus.md) -- and agree exactly on shape, values, and, for the duplicate-absorbance files, on which occurrence is canonical. Exact digests, per-asset shapes, and value checksums are recorded in docs/evidence/native-opus-reader-conformance.json.

BF_lo_01_soil_cal.1 is authored by an opusreader2 copyright holder and tied to a published, peer-reviewed dataset. Three other upstream files were supplied by third-party GitHub issue reporters whose issue threads do not contain an explicit redistribution grant. SpectraSherpa deliberately does not bundle or claim those files under the package MIT licence.

These files also motivated a scientific-identity fix: the reader previously required a data block's single status candidate to reproduce that status block's recorded value envelope, which 617262_1TP_C-1_A5.0 -- a real, published acquisition -- does not do, and refused every same-type duplicate pairing outright rather than attempting to disambiguate it by value, which 629266_1TP_A-1_C1.0 and BF_lo_01_soil_cal.1 both exercise. Both are fixed; see docs/evidence/native-opus-reader-conformance.json and the OPUS implementation record in docs/plan/canonical-dag-managed-optimization-plan.md.