Simultaneous observations of rain events by TRMM precipitation radar and the MU radar

Among the ground-based radars used for TRMM PR validation, the MU (Middle and Upper atmosphere) radar of Kyoto University, Japan has unique capability of being able to observe the background atmospheric motion including the effect of turbulence, as well as the precipitation component. It is thus possible to compensate for the mean wind component in deriving the Doppler spectra of precipitation. The authors have proposed to provide a precise ground validation using this capability. The accuracy of the validation was partly verified using the airborne radar CAMPR developed by the Communications Research Laboratory on July 8, 1996. On the other hand, the limited steerability of the 100-m array antenna of the MU radar, which is 30 degrees from the zenith, restrict the chance of simultaneous observations with the two radars very small. They developed a special observation mode, which runs interruptedly among other observation schedules, so that they can make the maximum use of chances, and have so far obtained ten sets of data. The authors briefly examine the initial results of the observations.