E-GVAP: The EUMETNET EIG GNSS water vapour programme
Aside from main geodetic applications, GNSS has become an established atmospheric observing system for water vapour with high spatiotemporal resolution. In Europe, the application of GNSS in meteorology is a well-established field in both research and operation. Since 2005, E-GVAP (The EUMETNET EIG GNSS water vapour programme, egvap.dmi.dk) is in charge of the collection and quality control of operational GNSS tropospheric products for numerical weather models (NWM). GFZ is one of the operational E-GVAP Analysis Centres (ACs) and processes with GFZ EPOS software more than 600 GNSS stations with a time delay better than 15 minutes after each hour (near real-time).
For monitoring purposes GNSS-derived tropospheric products are daily compared to the corresponding tropospheric parameters derived from a global numerical weather model, the Global Forecast System (GFS) of the National Centers for Environmental Prediction (NCEP) (www.ncep.noaa.gov).
The tropospheric products provided by GFZ are used by several European weather services like the Met Office, the United Kingdom's national weather service, and Météo-France, the French national meteorological service for their day-by-day forecasts.
Additionally, GFZ provides as the only one of the E-GVAP Analysis Centres the Slant Total Delays (STDs) with a time resolution of 2.5 minutes. At the same time, these specific data from up to 30 navigation satellites are currently used for studies to improve the precipitation forecast of the German Weather Service DWD.
References
Wickert, J., Dick, G., Schmidt, T., Asgarimehr, M., Antonoglou, N., Arras, C., Brack, A., Ge, M., Kepkar, A., Männel, B., Nguyen Thai, C., Oluwadare, T. S., Schuh, H., Semmling, M., Simeonov, T., Vey, S., Wilgan, K., Zus, F., GNSS Remote Sensing at GFZ: Overview and Recent Results. - ZfV: Zeitschrift für Geodäsie, Geoinformation und Landmanagement, 145, 5, 266-278, doi: 10.12902/zfv-0320-2020, 2020
Lammert, A., Hansen, A., Ament, F., Crewell, S., Dick, G., Grützun, V., Klein-Baltink, H., Lehmann, V., Macke, A., Pospichal, B., Schubotz, W., Seifert, P., Stamnas, E., Stevens, B. (2019): A Standardized Atmospheric Measurement Data Archive for Distributed Cloud and Precipitation Process-Oriented Observations in Central Europe. - Bulletin of the American Meteorological Society, 100, 7, pp. 1299-1314, DOI: doi.org/10.1175/BAMS-D-18-0174.1
