# Sentinel-2 MSI Synthetic Raw Data Generator **Runs S2B L1B *backwards* through the exact inverse of the operational Synthetic L0 → L1B radiometric chain to reconstruct the L1A → L0plus → Synthetic L0 EOPF product chain** (focal-plane DN, 12 detectors × 13 bands). Step by step the reverse chain **inverts** each operational radiometric correction — offset, relative-response/PRNU, dark, un-bin, SWIR re-stage, defective pixels, crosstalk and on-board equalization — against the **operational GIPP** (per-pixel dark + relative response), reconstructing the focal-plane counts. Every radiometric coefficient is **ESA-sourced ESA-sourced** — nothing is fitted or synthetic. **MTF-deconvolution is OFF**, so the PSF and noise are **not** re-applied. Its purpose is to reconstruct the **L1A / L0plus / Synthetic L0 product chain** from a S2 L1B and validate it against the reference ESA L0 `img`. A calibration sub-set derives the coefficients from synthetic CSM sun-diffuser + dark acquisitions (the inverse-crime cure). Implemented from the public L1 ATBD and the GIPP data only. Source repository: [gitlab.eopf.copernicus.eu/ipf/s2-msi-raw-generator](https://gitlab.eopf.copernicus.eu/ipf/s2-msi-raw-generator) ## Reverse L1B → L1A → L0plus → Synthetic L0 reverse chain The generator's headline path: an **S2B L1B** run *backwards* through the full operational radiometric chain into the EOPF EOPF product chain — Synthetic **L1A** (decompressed raw counts) → **L0plus** (CCSDS-122 ISP + ancillary) → **L0** (decoded `img`, **format-identical to the ESA `S02MSIL0__` product**). Validated against the reference ESA L0 `img` for all 13 bands (detector d05): the **ten 10 m + 20 m bands agree to ≤ ~4 DN**; the three native-60 m bands (B01/B09/B10) are limited by the ×3 un-bin. Full per-band table, S8-SWIR / framing figures and the run command: [Reverse chain V&V report](vv/s2_l1b_e2e_run_report.md).  The **L0plus** stage packages the Synthetic L1A as CCSDS-122 ISP records; the codec round-trip is lossless — `decode(L0plus)` reproduces the L1A counts bit-exactly (overall lossless ratio ≈ **3.66×**), a supporting check on the reverse chain's product assembly. The "reference ESA L0" panels contain **modified Copernicus Sentinel data 2024** (Sentinel-2B, 2024-04-08), shown as low-resolution demo previews only — no raw product data is redistributed. ```{toctree} :maxdepth: 1 :caption: "Project documentation:" atbd/atbd sss srs ird sdd/index djf icd dpm/index vv/index cidl scf srf ``` ```{toctree} :maxdepth: 1 :caption: "Management & assurance:" sdp spa-plan srevp risk-register qr ``` ```{toctree} :maxdepth: 1 :caption: "User documentation:" sum srn API Reference Source Repository (GitLab) license ```