Publications

GPS radio occultation experiments onboard low earth orbiting satellites (CHAMP, SAC-C) offer a prominent method for global and continuous monitoring of the Earth's atmosphere. Data assimilation studies using radio occultation data have already shown that this new type of remote sensing technique improves the accuracy of global and regional weather analyses and predictions. The use of products obtained from radio occultation data as, e.g., refractivity, temperature, or humidity, by weather service centers requires an operational data processing system generating and delivering data products automatically in certain time limits. Since one year such a near real time data processing system is operated at GFZ Potsdam with radio occultation data from the German satellite CHAMP (Challenging Microsatellite Payload). This system, the CHAMP Atmospheric Processor (CAP), will be introduced. The controlling and scientific components including ground infrastructure, data flow and software modules are discussed. CAP is designed to be easily extended by additional scientific modules or input data. It also allows for an extension to other single- or multi-satellite occultation missions as, e.g., GRACE to be launched in March 2002. By the end of 2001 about 36.000 occultations in various periods were recorded. More than 80% of the measurements could be processed to derive vertical profiles of dry temperature and specific humidity. Extensive statistics from nearly one year of CHAMP radio occultation data will be presented.

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Schmidt, T.; Wickert, J.; Marquardt, C.; Beyerle, G.; Reigber, C.; Wehrenpfennig, A. (2002): The near real time data processing system for GPS radio occultation data from CHAMP at GFZ Potsdam. 27th General Assembly of the European Geophysical Society (EGS) (Nice 2002).