GLASS, a Tool for Quality-Controlled GNSS Data and Products Dissemination.
Résumé
Europe is covered by various networks of GNSS stations maintained by different agencies with different technical and scientific objectives. The EPOS-IP (European Plate Observing System - Implementation Phase) project aims to harmonize and standardize data collection and processing and to design and establish dedicated products and services that benefit the existence of national and pan-European infra-structures (in particular EUREF), optimized for Solid Earth Research applications. We present here the efforts carried out by the members of this group to create a distributed software architecture called GLASS, a tool for quality-controlled dissemination within the EPOS, which during the operational phase, to start in 2019, shall provide GNSS data and derived products (coordinates, velocities and strain rates) from thousands of stations in Europe region. We describe the data flows from data suppliers and analysis centers to the various EPOS data portals and the integration into the overall EPOS system. In particular we describe the quality control steps that are performed in the GNSS Data and Products, from validating the station log files, obtaining quality metrics of RINEX files and there role in monitoring the overall system strength. We also describe how time series and other GNSS products computed at several analysis centers are compared and how the detection of outliers and verification of jumps are dealt with. In terms of Data and Product Dissemination we detail the overall software and portal components, the technologies that are used and resulting API's and their descriptions in formal languages for integration into the central EPOS systems software and existing workflow. EPOS-IP is a project funded by the ESFRI European Union.