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 primary grassland status layer at 10m spatial resolution was produced with a hierarchical spatio-temporal classification of time features derived from Sentinel-2A+B time series (Level-2A data) using a Random Forest (RF) classifier with 200 trees. The selected time window ranges from 01-02-2018 to 30-11-2018, adapted to regional conditions where needed. In total, 137 statistical time features have been calculated and more than 700,000 samples were automatically collected from the LUCAS 2018 database, various CLMS products and additional manual sampling. The final product will be accompanied by a series of expert and reference products (PLOUGH, GRAVPI, Confidence Layer).

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 (10m) according to ortho-rectified satellite image base (Sentinel-2 Level-2A) delivered by ESA.

Thematic target accuracy: 85% overall accuracy within each bio-geographic region.

Achieved overall accuracy: 95.31% with a 95% confidence level applied. Thematic accuracy has been assessed using a stratified random point sampling approach with 11708 points (area weighted), visually interpreted using VHR_IMAGE_2018 data, Sentinel-2 time series data and complemented by additional data sources like LPIS data sets and Google Earth imagery.

More information about this product can be found in their product specifications here: https://land.copernicus.eu/user-corner/technical-library/hrl-grassland-2018-user-manual.