C4G UBI contribution for EPOS GNSS Products Dissemination

Work done by the GNSS Data & Products Thematic Core Services in the scope EPOS was promoted at the 19th General Assembly of WEGENER 2018 on earth deformation and the study of earthquakes using geodesy and geodynamics. There were two posters (the C4G/UBI contribution for the EPOS GNSS Products Dissemination and the EPOS GNSS Data Gateway: concept and access) and one presentation (Present-day crustal deformation in Romania from continuous and episodic GNSS measurements).

The C4G/UBI contribution for the EPOS GNSS Products Dissemination – This poster presented the efforts carried out by C4G/UBI in the framework of the EPOS (European Plate Observing System) project to support the harmonization and dissemination through a product portal of products derived from GNSS data: position time series, velocity fields and strain rate maps.

The poster was produced by the C4G/UBI team (Machiel Bos, Paul Crocker, Rafael Couto, Rui Fernandes, Rui Cardoso, Hugo Gonçalves, José Manteigueiro, Fábio Pereira and André Rodrigues). It presents that C4G/UBI will validate the velocity solutions computed by the different EPOS/EUREF analysis and combination centres. This is done by 1) comparing the solutions produced by the different methodologies; and 2) analysing each time series by screening for outliers and ensuring that jumps in the time series are being detected. C4G/UBI will be also responsible for estimating proper uncertainties for the velocities using Hector.

PDF iconC4G UBI contribution for EPOS GNSS Products Dissemination

Developments on the EPOS-IP strain rate product

The main topic is always seismology at the General Assembly of the European Seismological Commission (GA ESC). This year, the 36th Assembly was held in Valletta, Malta, from September 2nd to the 7th , 2018. The event was organized by the Department of Geosciences of the University of Malta, and it brought a new approach: a presentation about the work done by EPOS TCS GNSS Data and Products.

Athanassios Ganas (NOA), an EPOS TCS GNSS member, introduced this TCS by presenting for the very first time the preliminary product which is the strain rate map of western Eurasia. “In this contribution, were presented preliminary results from 452 permanent European GNSS stations, operating until 2017 and processed at UGA-CNRS (Université Grenoble Alpes, Centre National de la Recherche Scientifique)”, says Ganas.

Strain rate field – According to him, to calculate the strain rate field, they used two open-source algorithms recommended by EPOS-IP, namely the VISR (Velocity Interpolation for Strain Rate) algorithm (introduced by Shen et al., 2015) and STIB (Strain Tensor from Inversion of Baselines), developed by Masson et al., (2014) as well as the SSPX software suite (Cardozo and Allmendinger, 2009).

PDF iconDevelopments on the EPOS-IP Pan-European strain rate product

GLASS, a tool for quality-controlled GNSS Data and Products dissemination

Paul Crocker, professor from University of Beira Interior (UBI) and an EPOS TCS GNSS Data and Products member, presented a poster about GLASS at AGU Fall Meeting. The event, hosted from December 10th to 14th, at Walter E Washington Convention Center, had the poster presentation addressed at Hall A-C (Poster Hall) on Wednesday (December 12th, 2018), from 13:40 to 18:00 (Washington, D.C. time).

According to the abstract submitted, “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”.

Paul Crocker (UBI) presenting the poster about GLASS at AGU Fall Meeting.Distributed software architecture – Therefore, the idea has been to present the efforts carried out by the members of EPOS TCS GNSS Data and Products to create a distributed software architecture called GLASS, a tool for quality-controlled dissemination within the EPOS. During the operational phase, to start in 2019, this shall provide GNSS data and derived products (coordinates, velocities and strain rates) from thousands of stations in Europe region.

Data flows – “We took the opportunity to 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 have described 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 their role in monitoring the overall system strength”, explains Paul Crocker.

Several analysis centers – According to Crocker, was also described 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 had been detailed 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.

Authors – The authors of this poster, entitled “GLASS, a tool for quality-controlled GNSS Data and Products dissemination”, are: Paul Crocker (UBI), Jan Dousa (Research Institute of Geodesy), Mathilde Vergnolle (CNRS), Carine Bruyninx (Royal Observatory of Belgium), Machiel Simon Bos (UBI), Rui Manuel Silva Fernandes (UBI), Benedikt Ofeigsson (Icelandic Met Office), Petr Bezdeka (Research Institute of Geodesy), Rui Cardoso (UBI), Rafael Couto (UBI), Andras Fabian (Observatoire Royal de Belgique), Juliette Legrand (Royal Observatory of Belgium), Khai-Minh Ngo (Géoazur – Université Nice Sophia Antipolis), Tim Sonnemann (University of Iceland) and Pavel Vaclavovic (GOP/RIGTC).

EPOS-IP is a project funded by the ESFRI European Union.

PDF icon GLASS: a tool for quality-controlled GNSS Data and Products dissemination.pdf

EPOS TCS GNSS Thematic Core Service @ European Plate Observing System

On May 30th until June 1st, 2018, EPOS TCS GNSS Data and Products participated to the EUREF 2018 Symposium, which was hosted in Amsterdam, Netherlands. Therefore, to disseminate this Thematic Core Service, Rui Fernandes, coordinator for EPOS TCS GNSS Data and Products, had been chosen as a representative to speak about EPOS at EUREF Symposium. To leverage EPOS awareness, he started by reminding the audience that “EPOS is a long-term project for the integration of research infrastructures for Solid Science in Europe. Therefore, one of the three priority projects of European Commission within ESFRI”.

https://intranet.epos-ip.org/modules/file/icons/application-pdf.pngEPOS TCS GNSS Thematic Core Service @ European Plate Observing System