Development of a tomographic water vapour sounding system based on GNSS data

• Applicants: Dr. Armin Raabe; Professor Dr. Jens Wickert
• Co-Applicant: Professor Dr. Hans-Gert Kahle
• Subject Area: Atmospheric Science
• Term: from 2007 to 2013
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 36432749

The development of a GPS water vapour retrieval system for Germany is described. The humidity information as extracted from GPS data is used to reconstruct spatially resolved water vapour distributions. Such moisture data are essential in various fields of meteorology and geoscience, e.g., weather forecast, hazard mitigation and water management. In the first project period advanced techniques for the derivation of line-of-sight (slant) atmospheric delay data from about 270 German GPS ground stations have been developed and validated. Several tomographic reconstruction techniques have been implemented and tested. In the second period extensive validation and verification studies shall be carried out. The reconstructed humidity field will be compared with meteorological observations such as radiosonde profiles and water vapour radiometer data and with numerical weather model fields as well. The information provided by the GPS observations will be estimated and related to the error of the reconstructed humidity field. A combination of these information will be used to estimate the error quality together with the reconstruction. In parallel to the validation studies all steps of the data processing and tomography will be further improved and optimized.

• DFG Programme: Research Grants
• International Connection: Switzerland
• Participating Persons: Dr. Galina Dick; Dr. Gerd Gendt; Professor Dr. Gerd Tetzlaff