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 main part of the Grassland Change (GRAC) processing and time-series analysis is carried out in the processing of the herbaceous layer as this builds the fundament of any subsequently derived layer. For the change detection, it is specifically important to include a sophisticated time-series analysis into the herbaceous classification to prevent false class-flips between consecutive years and therefore to avoid artificial changes introduced by classification noise. This specific part is achieved by calculating the (fast) dynamic time warp (DTW) of the time-series of two subsequent years. The Plant Phenology Index from the High Resolution Vegetation Phenology and Productivity is used for this analysis.

This dataset is a continuation of the HRL Grassland Change timeseries, generated on a 3-year update cycle since the 2015-2018 comparisson. The models and input data used to generate the product have evolved and therefore higher quality is to be expected as the timeseries progress.

Quality assurance follows the ISO9000 standards for Quality Management and comprises of dedicated procedures of ongoing 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 accuracies 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) Thematic Accuracy,

(iv) Temporal quality and

(v) Usability.

Each of them (excl. the Thematic Accuracy hereafter) forms a section in the QA/QC Procedures.