Software release note

Software release note#

Project: Sentinel-2 MSI Synthetic Raw Data Generator (s2_msi_raw_generator) · DRD: ECSS-E-ST-40C Rev.1 (Software release document, SRelD). Full history: ../CHANGELOG.md.

1. Release#

  • Package: s2_msi_raw_generator · version: 0.3.0 · date: 2026-07-02.

  • Status: all-S2 L1B reverse chain run (S2B L1B → L1A → L0plus → Synthetic L0); 201 tests pass (v0.3.0); GitLab CI green on main.

  • License: Apache-2.0.

2. Contents#

  • Reverse chain (reverse.py): run a S2 L1B backwards through the exact inverse of the operational L0→L1B chain — invert offset, relative-response/PRNU, dark, un-bin, SWIR re-stage, defective, crosstalk, on-board-eq — with MTF-deconvolution OFF (PSF and noise are not re-applied), reconstructing L1A → L0plus → Synthetic L0; ISP packetization (isp.py) and Synthetic L0 RAW EOProduct assembly (l0product.py).

  • S2 L1B ADFs: the original operational-GIPP reader (gipp.py → per-pixel dark + relative response that the reverse chain inverts) and the per-unit SRF spectral characterisation / sensor model (sensor.py, used for the SWIR re-stage and relative-response inversion).

  • Exact radiometric inverse (forward_radiometric_atbd.py) the reverse chain uses to undo gain/offset (\(X = A\cdot G\cdot L + D \rightarrow\) recover \(L\)); the forward relation appears only as the thing being inverted. Plus the calibration sub-set (calibration.py, cal-DB derivation).

  • Documentation set (this release): ATBD (issued v1.0), SRS, SDD, ICD, DPM, V&V plan + report, SUM, this SRN, CIDL, SCF, SRF, SDP; plus README, CHANGELOG, LICENSE.

  • Scripts: demo_reverse_real.py (reverse chain), demo_build_l0.py (L0 assembly), demo_calibration.py (cal-DB), derive_prnu_dark.py (dark / relative-response derivation) — since consolidated into scripts/run_pipeline.py.

3. Changes (this cycle)#

v0.3.0 — S2 L1B reverse chain: CCSDS 122.0-B lossless codec (ccsds122.py, ICD-IF-C122); compressed-ISP canonical Synthetic L0 (isp.packetize_stream, ground decode read_l0_isp_dn); EOPF PSFD §3 naming (naming.py, ICD-IF-NAME); S2B L1B run backwards to a Synthetic L0 that is validated against the reference ESA L0 img — the 10/20 m bands agree to ≤ ~4 DN — with the L0plus stream compressed losslessly at 3.66× (docs/vv/s2_l1b_e2e.md); products in the package registry e2e-s2-l1b/0.3.0; Release v0.3.0.

  • Operational GIPP → per-pixel dark + relative response (replaces the DQR-summary dark / seeded PRNU).

  • Official L1 ATBD raw relation \(X = A\cdot G\cdot L + D\) (true 12-bit DN) is the forward relation the reverse chain inverts — undo the offset \(D\), then the gain \(A\cdot G\) — to recover L1A/Synthetic L0. Noise is not re-applied (MTF-deconvolution OFF).

  • Calibration sub-set — synthetic CSM diffuser + dark → derived coefficients (inverse-crime cure).

  • Documentation: ATBD issued v1.0; added the full ECSS-E-ST-40C DRD set, LICENSE (Apache-2.0), CHANGELOG.

4. Known limitations#

  • L1C entry + geometry reverse — cancelled (not applicable to an L1A/L1B entry; no orthorectification to undo). Geometry inversion is out of scope.

  • Deferred requirements: credentialed ADF service (REQ-FUNC-043), configurable PU orchestration (REQ-FUNC-053), Dask distribution (REQ-FUNC-062).

  • Radiometric validation is against the reference ESA L0 img (the Synthetic L0 agrees to ≤ ~4 DN on the 10/20 m bands). The publicly available EOPF test L1B/L1A is DN-scaled (not a physically-calibrated radiance product), and physically-calibrated S2 L1A/L1B is not publicly distributed.

  • A dark-calibration (night/ocean) granule was not available; the dark is the per-pixel GIPP value (DQR-range), not derived from a dedicated dark acquisition.