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Background on the CHAMP Experiment

CHAMPIn the year 2000, the German satellite CHAMP was launched carrying a new generation of GPS receivers, the "Blackjack", developed at JPL. The mission is managed by theGeophysikalisches Forschungszentrum (GFZ) at Potsdam (Germany) which is the other main data processing center for CHAMP radio occultations. The CHAMP Blackjack started collecting atmospheric profiles on April 6, 2001 and since then has been collecting up to 250 daily occultations during much of 2001. This receiver has enhanced capabilities over the older generation GPS/MET instrument which include "enhanced codeless" tracking (i.e., the ability to track the encrypted GPS signals), higher signal-to-noise ratio, and lower tracking in the atmosphere. The Blackjack GPS receiver is capturing high vertical resolution profiles over land and oceans and is providing data complementary to other sounding techniques. From this point on, the amount of data is expected to increase with ongoing enhancements of the receiver's software. 

JPL ftp server for CHAMP data

Early Results from CHAMP


Statistics of 962 CHAMP occultations collected during 8 days in April, 2001. From left to right, the mean and standard deviation of fractional refractivity difference, temperature difference and water vapor pressure difference between CHAMP occultations and NCEP analysis interpolated to the location and time of the occultations are shown.