Dec 18, 2018 by ROB

Presently, the GNSS research program of the ROB comprises the following topics:

  • Integration of Belgium in international geodetic networks. In order to achieve this goal, the ROB installed in Belgium a network of permanent GNSS receiver stations. In addition to the processing of our own data, we also process the data originating from international GNSS networks.
  • Determination of slow ground deformations using GNSS measurements (Study of local and regional tectonics)
  • Study of the error sources affecting high precision GNSS positioning.
  • Study of the effect of the atmospheric (ionospheric and tropospheric) refraction on the GNSS signal propagation and the errors induced on the GNSS observations.
  • Monitoring of the Earth's atmosphere (Ionosphere and troposphere)
  • Integration of Belgium in the international network used for the realization of UTC (Universal Time Coordinated), using our atomic clocks linked to the network through GNSS measurements.

We participate to the following programs/projects:


EPOS) is a new European research infrastructure that combines (national) solid Earth science infrastructures and their capital of human expertise, data, and services into one integrated system in support of Solid Earth Science. It gathers input from geodesy, geology, seismology, volcanology, or geomagnetism. Together, they offer the key to understand the complex dynamic Earth system.
Presently EPOS is still in its construction phase, which is supported by the H2020 project EPOS-IP (2015-2019) to which ROB participates. From 2019-2020, EPOS will provide operational services.
EPOS is organized in Thematic Core Services (TCS). In each TCS, selected Service Providers, such as ROB, will provide (from 2019-2020 on) the key services to EPOS. In addition, the EPOS architecture also includes Integrated Core Services (ICS). The ICS will provide the tools to facilitate the discovery of data, data products, software and services, and the integration of these resources to fulfill user requests across the EPOS community.
The TCS GNSS data and products will consist of a European network of more than 3000 GNSS stations and it will provide access to their GNSS data, metadata and products.
As one of the founding members of EPOS, Belgium, through the ROB, is playing a key role in the GNSS component of EPOS. It will be responsible for collecting and validating the metadata of the EPOS GNSS stations and will also ensure the long-term monitoring of the data quality of the GNSS stations.


EUREF is the IAG (International Association of Geodesy) Reference Frame Sub-Commission for Europe and deals with the definition, realization and maintenance of the European Reference Frame - the geodetic infrastructure for multinational projects requiring precise geo-referencing - in close cooperation with the IAG components (Services, Commissions, and Inter-commission projects) and EuroGeographics, the consortium of the National Mapping Agencies (NMA) in Europe. EUREF has been developing a set of activities related to the establishment and maintenance of European Terrestrial Reference System (ETRS89) and European Vertical Reference System (EVRS). A key instrument in maintaining ETRS89 is the EUREF Permanent Network (EPN), a network of continuous observing GNSS stations covering the European continent.
The GNSS team of ROB contributes to the EPN with four of its permanent GNSS stations. In addition, it hosts the Central Bureau of the EPN, maintains its historical data archive, operates one of the EPN data processing centers, and is reponsible for the computation of the official ETRS89 coordinates of the EPN stations.

International GNSS Service:

The International GNSS Service (IGS), is a voluntary federation of more than 200 worldwide agencies that pool resources and permanent GPS & GLONASS station data to generate precise GPS & GLONASS products. The IGS is committed to providing the highest quality data and products as the standard for GNSS in support of Earth science research, multidisciplinary applications, and education. You can think of the IGS as the highest-precision international civilian GPS community.
The GNSS team of ROB participates to the IGS with its GNSS reference station located at the ROB premisis and also contributes to the IGS governance and development of its network infrastructure.

Solar Terrestrial Centre of Excellence:

The Solar-Terrestrial Center of Excellence is a scientific project which aims to create an international expert center for Solar and Solar-Terrestrial research and services. The STCE clusters the know-how of three Belgian Federal institutes: Royal Observatory of Belgium (ROB), Royal Meteorological Institute (RMI) and Belgian Institute for Space Aeronomy (BISA). and aims to study the relation between the Sun and the Earth.
The GNSS team of ROB participates to the STCE by maintaining a GNSS observation infrastructure and monitoring the Earth's troposphere and ionosphere.


The EUMETNET GPS water VApour Program (E-GVAP) is a program running under the aegis of the European Network of Meteorological Service (EUMETNET). This project has been setup to collect near real-time (NRT) ground-based GNSS tropospheric delay and water vapour estimates on the European scale. This information is provided this information to EUMETNET partners for operational meteorology. The ultimate goal of the project is to improve weather forecasts. This is achieved in close collaboration with the geodetic community who operate the 11 analysis centres that provides the NRT tropospheric delay estimates. ROB is one of these GNSS analysis centres. This is done in close collaboration with the geodetic community in Europe.


The basis of the legal time in the world is UTC, the Universal Time Coordinated. It is computed by the BIPM from a weighted average of atomic clocks distributed around the world; five of these clocks are located in the time laboratory of the ROB. The clocks of the different laboratories are compared using GNSS. The research developed at the ROB aims to improve the precision of this comparsion technique in order to be able to compare the most precise atomic clocks in the world. The ROB also provides for Belgium a realization of UTC, named UTC(ORB), which is therefore the most precise time for Belgium and which is disseminated via the Internet (NTP).