XML Schema Definitions (XSD)
The metadata within a SENTINEL-2 Level-1C and Level-2A Compact Naming Convention product is contained in the root XML (eXtensible Markup Language) file within the product.
SENTINEL-2 L1C and L2A Compact naming Convention product physical structure
This metadata in XML format conforms to the XSD (XML Schema Definition) Schemas (S2_PDI_Level-1C_Tile_Metadata.xsd and S2_User_Product_Level-2A_Metadata.xsd respectively) that accompany the Product Specification Document (PSD) available from the Sentinel-2 Document Library.
XSD is a World Wide Web Consortium (W3C) recommendation that specifies how to formally describe the elements in an Extensible Markup Language (XML) document. More information can be found on the W3C website.
The processing baseline (PROBAS) evolves to take into account corrections of errors in the processing chain and introductions of new product features or processing steps (e.g. introduction of the geometric refinement). The evolutions of the processing baseline are tracked and justified in the Data Quality Report published on a monthly basis. The relationship between each PROBAS, the XSD, and the PSD is set out in the Table below, and highlighted in the Data Quality Report (DQR) is available from the Sentinel-2 Document Library.
Note: The public archive of Sentinel-2 products was opened with processing baseline 02.00 (Level-1C).