Access to data is based on a principle of full, open and free access as established by the Copernicus data and information policy Regulation (EU) No 1159/2013 of 12 July 2013. This regulation establishes registration and licensing conditions for GMES/Copernicus users.

Free, full and open access to this data set is made on the conditions that:

1. When distributing or communicating Copernicus dedicated data and Copernicus service information to the public, users shall inform the public of the source of that data and information.

2. Users shall make sure not to convey the impression to the public that the user's activities are officially endorsed by the Union.

3. Where that data or information has been adapted or modified, the user shall clearly state this.

4. The data remain the sole property of the European Union. Any information and data produced in the framework of the action shall be the sole property of the European Union. Any communication and publication by the beneficiary shall acknowledge that the data were produced “with funding by the European Union”.

The Dominant Leaf Type Change (DLTC) 2015-2018 is a change product based on the 20m Tree Cover Change Mask (TCCM) 2015-2018 considering changes of the leaf type by taking the Dominant Leaf Type (DLT) information of the two reference years 2015 and 2018 into account. The layer has a 1 pixel boundary filter applied in order to mitigate geometric imprecisions between the input layers 2015 and 2018, caused by the different satellite input data characteristics. Change classes are provided with a Minimum Mapping Unit (MMU) of 1 ha. The product covers the whole EEA39 area and is provided in European projection. National products might show a broken MMU due to reprojection.

Quality assurance follows the ISO 9001:2015 standards for Quality Management and comprises of dedicated procedures of quality checks (QA breakpoints) during implementation of the production chain, in order to keep persistent control over the various stages of production, assure fitness-for-purpose of the end-products and that all quality requirements are fulfilled. Priority has been given to the target thematic accuracy to be achieved by each product, as well as to the issues of product consistency (spatial, thematic, temporal) and homogeneity. Quality Assessment: The quality assessment has been performed according to INSPIRE Data Specifications. The data quality elements considered are: (i) Completeness, (ii) Logical Consistency, (iii) positional accuracy, (iv) Thematic Accuracy, (v) Temporal quality and (vi) Usability.

Geometric accuracy (positioning scale): Less than one pixel (20m) according to ortho-rectified satellite image base delivered by ESA.

Thematic target accuracy: 90% producer and user accuracy for change classes.

Final validation results DLTC 1518 at pan-European level: 98.16% overall accuracy with a 95% confidence level applied (no tree cover: 98.47% producer accuracy and 98.67% user accuracy; new broadleaved cover: 71.50% producer accuracy and 92.24% user accuracy; new coniferous cover: 96.78% producer accuracy and 98.77% user accuracy; loss of broadleaved cover: 88.62% producer accuracy and 70.64% user accuracy; loss of coniferous cover: 72.67% producer accuracy and 91.86% user accuracy; unchanged areas with tree cover: 98.02% producer accuracy and 97.51% user accuracy). The class potential change among dominant leaf types has not been assessed.

Thematic accuracy has been assessed using a stratified random sampling approach with 11,695 points (area weighted), visually interpreted using VHR_IMAGE_2018, VHR_IMAGE_2015 and Sentinel-2 time series data, complemented by additional data sources like virtual globes (e.g. Google Earth Pro).

The production process is described and explained in detail in the User Manual Tree-cover/forest and change 2015-2018 available here: https://land.copernicus.eu/user-corner/technical-library/forest-2018-user-manual.pdf.