1,2,2,3,4,5,7,10,11,- 1Karlsruhe Institute of Technology (IMK-IFU), Institute of Meteorology and Climate Research, Garmisch-Partenkirchen, Germany (christian.chwala@kit.edu)
- 2Czech Technical University in Prague, Department of Hydraulics and Hydrology, Czech Republic
- 3Royal Netherlands Meteorological Institute (KNMI), R&D Observations and Data Technology, the Netherlands
- 4Delft University of Technology (TU Delft), Department of Water Management
- 5National Research Council, Institute of Electronics, Computer and Telecommunication Engineering (CNR-IEIIT), Milan, Italy
- 6Deutscher Wetterdienst, Department of Hydrometeorology, Offenbach am Main, Germany
- 7School of Electrical and Computer Engineering, Tel Aviv University, Israel
- 8Swedish Meteorological and Hydrological Institute, Norrköping, Sweden
- 9Faculty of Science and Technology, Norwegian University of Life Sciences, Ås, Norway
- 10Royal Meteorological Institute of Belgium, Belgium
- 11Department of Geography, Ghent University, Belgium
- 12Institut de Recherche pour le Développement, GET, Toulouse, France
Accurate quantitative precipitation estimation (QPE) remains a critical challenge in many data-scarce regions, particularly across low- and middle-income countries. Recent research in Sri Lanka, Burkina Faso, Zambia, Nigeria, Ghana and Cameroon has demonstrated that Commercial Microwave Links (CMLs) can bridge this gap, providing rainfall data with high temporal resolutions (1–15 minutes) that can outperform satellite products like IMERG in both accuracy and spatial detail, especially in densely populated urban areas where CML density is high.
While the technical feasibility of CML-based rainfall observation is well-established, its widespread implementation is often hindered by legal, business, and organizational barriers. To address these issues, the SetGMDI project, a strategic outcome of the COST Action OpenSense, is working on setting up the Global Microwave Data Collection Initiative (GMDI). The SetGMDI consortium, comprising mobile network operators (MNOs), hardware vendors, national meteorological and hydrological services (NMHSs), and academia, is building a sustainable, scalable solution for global collection of CML data for rainfall monitoring.
In this contribution, we present results from the first pilot studies utilizing a prototype of the technological core system of GMDI: The Data Collection, Archiving, and Processing (CAP) system. The CAP system enables real-time data flows and interactively explores large data archives of CML data combined with meteorological datasets. Furthermore, we discuss the legal and organizational framework necessary to formalize long-term data-sharing agreements with MNOs, balancing commercial sensitivity with the public good resulting from improved precipitation observations.
The CAP system creates vital synergies by providing NMHSs with access to high-resolution data for hydrometeorological applications, while MNOs and vendors benefit from meteorological insights to optimize network management. By addressing both organizational and technical barriers, GMDI will significantly increase the global availability of CML data, improving rainfall observations in particular in the Global South. This will also pave the way for integrating satellite and CML rainfall estimates, ultimately strengthening flood early warning systems, water management, and climate adaptation strategies worldwide.
How to cite: Chwala, C., Fencl, M., Bareš, V., Overeem, A., Uijlenhoet, R., Nebuloni, R., Winterrath, T., Ostrometzky, J., Messer, H., van de Beek, R., Øydvin, E., Van Weverberg, K., and Gosset, M.: First results and future directions of the Global Microwave Data Collection Initiative (GMDI) to scale up the usage of commercial microwave link data for rainfall observation, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-20663, https://doi.org/10.5194/egusphere-egu26-20663, 2026.
