STUDY OF THE PERFORMANCE OF THE GLAST LAT AS A GROUND-BASED COSMIC RAY OBSERVATORY

The Gamma-ray Large Area Space Telescope (GLAST) is scheduled for launch in 2008. The Large Area Telescope (LAT) on board GLAST aims at performing gamma-ray astronomy in the energy range from 20 MeV up to 300 GeV. The potential of the LAT instrument and its scientific return will greatly depend on how accurately its performance is known and on the capability of monitoring it. The LAT is now integrated in the spacecraft and it has been tested as a cosmic-ray observatory. At present, it is undergoing the final environmental testing. This talk presents the results of studies of the performance of the LAT using cosmic-ray data obtained during ground testing. The analysis methods will carry over for studies of the in-flight performance of the LAT in the LAT Instrument Science Operations Center (ISOC), which supports mission operations and data processing for the LAT.