ReS4ToM · Real-Time GNSS for European Troposphere Delay Model

Real-Time GNSS for European Troposphere Delay Model

The project „Real-Time GNSS for European Troposphere Delay Model (ReS4ToM)” aims at developing “a novel real-time model of the troposphere by using Global Navigation Satellite Systems (GNSS) derived troposphere delays, gradient information and water vapor content”. Remote sensing of the troposphere with GNSS, so-called GNSS meteorology, provides observations of spatial and temporal resolution higher than any other technique and operates under all weather conditions. Therefore, hundreds of permanent GNSS stations in Europe are used by several analysis centers to operationally sense the troposphere under the E-GVAP project for monitoring water vapor by the help of GNSS. Troposphere products estimated from GNSS observations from the two oldest systems (GPS, GLONASS) are delivered with a latency reaching one hour. A real-time service, rather than a delayed provision of accurate troposphere products, from quad-constellation GNSS remains a goal. In addition to zenith total delay (ZTD), advanced troposphere products like horizontal gradients and slant delays gain more attention over recent years. The main product of GNSS meteorology, the ZTD, can be assimilated into numerical weather prediction (NWP) models in order to improve weather forecasting. This is particularly important for severe weather events (heavy rainfalls, hailstorms) for which reliable prediction remains a challenge. The dynamics of troposphere gradients can reveal additional information on troposphere asymmetry, and slant delays can be used to reconstruct the three-dimensional distribution of water vapor. With low-cost GNSS receivers, the tracking network can be densified and thus the spatial density of sensing the troposphere can be increased from tens to single kilometers. This allows to observe local dynamics of water vapor and increases the accuracy of forecasts for urban areas. Objectives of this Marie Skłodowska Curie Action (MSCA) were as follows: (a) to combine in a consistent and operational way multiple novel aspects of GNSS data processing; (b) to compute and validate a real-time GNSS-based troposphere delay model for users and to provide it online making use of open standards; (c) to check how such troposphere products support geodetic techniques and improve weather forecasting; (d) to investigate the potential and limitations of the low-cost GNSS receivers for GNSS meteorology. A parallel goal of the MSCA Individual Fellowship was to foster the development of the individual researcher, by increasing his visibility in the GNSS and meteorological communities, re-enforce his position of professional maturity in research and supervision, which will allow him to reach a promotion to achieve a fully independent academic position after this fellowship.

Data: CORDIS, © European Union