FAIR GNSS for collaborative Solid Earth science in Iceland: metadata, validation workflows and EPOS dissemination

Digital Solid Earth science relies on GNSS data services that are interoperable, traceable and reusable across institutions. In practice, GNSS station metadata and RINEX files are highly sensitive to manual handling and heterogeneous conventions. Inconsistencies in equipment histories, identifiers and file conventions can delay integration, reduce trust in downstream products, and hinder open dissemination. These challenges are amplified when coordinating across multiple data owners and legacy archives. 

We present an EPOS-aligned workflow for Icelandic GNSS metadata curation and service implementation developed across IMO, NordVulk and NSII. The work establishes a production-grade metadata and data integration pathway using a central integration layer coupled to EPOS services. Icelandic GNSS data are currently exposed via EPOS VOLC-TCS, while integration with the EPOS GNSS Thematic Core Service (GNSS-TCS) via GLASS (Geodetic Linkage Advanced Software System) is in the final stages of implementation to enable dissemination via the EPOS Data Portal. A key focus is reducing manual intervention and inconsistency while retaining necessary expert review. We describe automated validation and correction steps implemented in custom tooling (Tostools) developed in-house to streamline metadata curation and RINEX compliance, including consistency checks between station metadata, equipment change histories and RINEX content, generation of infrastructure-ready site logs for the M3G metadata service (the GNSS station site log standard used in EPOS/GLASS), and near-automated preparation of DOMES (Directory of MERIT Sites) identifier applications. The workflow also supports staged integration of heterogeneous datasets, including rescue and documentation of legacy University of Iceland campaign measurements and controlled dissemination based on data ownership constraints. 

As a motivating context, we refer to recent Reykjanes Peninsula deformation studies where dense GNSS observations were central to resolving rapid intrusive processes alongside other datasets, illustrating the value of reliable, well-documented and shareable geodetic data services (Sigmundsson et al., 2024). 

We conclude with practical lessons and recommendations for implementing FAIR and open-science aligned, infrastructure-ready GNSS services in a way that improves efficiency, reduces misunderstandings and accelerates collaboration. 

Reference: Sigmundsson, F., et al. (2024). Fracturing and tectonic stress drive ultrarapid magma flow into dikes. Science, 383, 1228–1235. https://doi.org/10.1126/science.adn2838.