In the "GPS Water Vapour Project" radio signals from the Global Positioning System (a satellite navigation and positioning system) were processed to derive estimates of the total column Integrated Water Vapour (IWV) content of the atmosphere. IWV data were retrieved for 5 GPS ground stations of the Dutch AGRS.NL network (Active GPS Reference System Netherlands). The retrieved IWV data had a temporal resolution of 6 minutes and were obtained under all weather conditions. Analysis of the data showed that the GPS IWV data had an accuracy comparable to IWV data derived from radiosonde and water vapour radiometer measurements.

Three Dutch institutes executed this two-year project on "GPS Water Vapour Meteorology" under contract with the Netherlands Remote Sensing Board (BCRS). The project lasted from September 1996 till October 1998. A summary of the results of the project is presented here. Presently the KNMI (i.e. the Atmospheric Research Section) does not process the GPS signals from the AGRS.NL network anymore. However GPS meteorology has gained already a firm place in atmospheric research and weather prediction. Presently KNMI (Observations and Modelling) is still strongly involved the COST action 716: Exploitation of ground based GPS for climate and numerical weather prediction application

The participants of the GPS Water Vapour Meteorology project were:

• Royal Netherlands Meteorological Institute (KNMI)
• Delft University of Technology (DUT)
• Survey Department of Rijkswaterstaat (MD-RWS)

The objectives of the project:

• set up an infrastructure for the acquisition, storage and processing of GPS-IWV data
• an assessment of the accuracy of GPS-IWV data
• investigate the usefulness of GPS-IWV data for weather forecast models and climate research
• study the feasibility of real-time processing of GPS-IWV data

Click here for more information on:

• Project description and selected results
• GPS related links

For information on this project contact: Henk Klein Baltink, last update: 19 May 2003.