The European Ground Motion Service (EGMS) is part of the Copernicus Land Monitoring Service (CLMS) lead by the EEA (European Environment Agency). EGMS is based on the full resolution InSAR processing (20x5m) of the European Space Agency (ESA) Sentinel-1 (S1). This massive geospatial timeseries dataset is composed by ~10.000 million timeseries distributed over 31 European countries. The baseline covers 2015-2020 and updates are being published on a yearly basis. It is publicly accessible at https://egms.land.copernicus.eu/ with a 3D viewer and download service. This open dataset consists of three product levels (Basic, Calibrated and Ortho). The Basic and Calibrated are offered at full resolution 20x5m (Line of Sight) whereas the Ortho product offers horizontal (East-West) and vertical (Up-Down) anchored to the reference geodetic model resampled at 100x100m. Sixense is coordinating a consortium responsible for the independent validation of this continental scale geospatial dataset. The validation goal is to assess that the EGMS products are consistent with user requirements and product specifications, covering the expected range of applications. To evaluate the fitness of the EGMS ground motion data service seven reproducible validation activities (VA) have been developed gathering validation data from different sources across 12 European countries: • VA1 – Point density check performed by Sixense. • VA2 – Comparison with other ground motion services carried out by NGI (Norwegian Geotechnical Institute). • VA3 – Comparison with inventories of phenomena/events performed by BRGM (French Geological Survey). • VA4 – Consistency check with ancillary geo-information carried out by NGI. • VA5 – Comparison with GNSS data performed by TNO (Dutch Geological Survey). • VA6 – Comparison with insitu monitoring data performed by GBA (Austrian Geological Survey). • VA7 – Evaluation XYZ and displacements with Corner Reflectors performed by TNO. The validation environment developed and maintained by Terrasigna includes all the necessary elements to perform all the validation tasks from data collection and description to execution of the different methodologies. The objective of this portable Kubernetes/Terraform cloud-based system is to guarantee reproducibility of all the validation activities: • A MinIO web-based validation data upload tool where scientists can upload their validation data and EGMS subsets. • A validation data catalogue based on GeoNode (based on OGC CSW) where all validation sites data is properly described and georeferenced to ensure reproducibility. • JupyterHub notebook environment where scientists can develop their validation scripts (Python/R). These notebooks produce graphs and figures to be included in the yearly validation reports.