PHASE: Interpolated phenological phase entry dates for winter wheat (Triticum aestivum, DWD Plant ID 202) in Germany

What's new in v1.9.0

Rebuild of the plant 202 (winter wheat) PHASE deposit against PhenoPhaseR v1.9.0. A minor, metadata-only version: the DOY posterior-mean and per-pixel BSE rasters, and the CAL / GEM / VAM / PIC tables, are byte-for-byte unchanged from v1.8.0. What changes is how the accuracy metrics are described in ro-crate-metadata.json, and the removal of an unverifiable crop crosswalk.

(Note: this deposit version and the PhenoPhaseR software version happen to coincide at v1.9.0; they are separate version lines and the match is incidental — the previous deposit was v1.8.0 against software v1.8.0.)

What changed

• Honest validation basis on every metric. Each per-(phase, year) quality measurement now records the regime that produced it, and three regimes are now kept distinct:
  • the VAM RMSE / MAE / R2 are hold-out — computed on the withheld validation partition of a single train/test split (ON = TN + VN) — and are now described as such, replacing an earlier wording that labelled them "cross-validation". In particular, cv_r2 is corrected to a hold-out coefficient of determination (the VAM R2 column, companion to cv_rmse / cv_mae); it is not the in-sample CAL DEV_EXPLAINED diagnostic, which continues to be reported only at the file level as a model-fit statistic;
  • the prediction-interval coverage (picp) and mean width (mpiw) retain their k-fold cross-validation description — genuinely a dedicated k-fold CV of the BSE uncertainty calibration (the production model is fit on all observations, so coverage cannot be measured in-sample), reported in the PIC tables.
• Single-source metric descriptions. Metric descriptions are now drawn from one shared registry, so the same measure can no longer be described differently across the PHASE and filter-variant crates.
• Removed: unverifiable crop → Wikidata crosswalk. The skos:exactMatch link from the crop concept to Wikidata has been removed. AGROVOC publishes no Wikidata match for these crop concepts (they link to USDA NAL, the World Bank thesaurus, and DBpedia), and the previously embedded Wikidata QID was unverifiable and, on checking, incorrect. The verified AGROVOC concept URI is retained (c_8412, winter wheat) as the sole, authoritative subject anchor.

Unchanged from the previous version

The DOY / BSE rasters and the CAL / GEM / VAM / PIC tables (byte-identical), the honest anchoring of the per-pixel uncertainty layer to fairagrodq:NumericalSpatialUncertainty (dct:isDefinedBy Säurich et al. 2026; explicitly not part of ISO 19157-1:2023) with its ParametricModelUncertainty expression principle and EmpiricalCoverageCalibration (the PICP/MPIW pairing), the ISO 19157-1:2023 anchoring of the accuracy metrics, the PROV-O provenance chain, the DCAT 3 / Dublin Core descriptors, and the RO-Crate 1.2 structure.

Coverage unchanged: plant 202 (DWD/JKI code, winter wheat, Triticum aestivum), phenological phases 10, 12, 15, 18, 19, 21, 24, years 1993–2025. Germany-wide, 1 km Cloud-Optimised GeoTIFF surfaces (DOY posterior mean + per-pixel BSE). The intermediate filter-variant inputs are at https://doi.org/10.5281/zenodo.20831130.