Rapid Imaging Observations of Clouds and Precipitations with High-resolution Millimeter-wave Radar FALCON-I

We have developed and are operating a cloud profiling FMCW (Frequency Modulated Continuous Wave) Doppler radar in millimeter wave range at 95GHz. It consists of two 1m-diameter antennas with high spatial resolution of 0.18 degree FWHM. A High range resolution of 15m is realized with the FMCW type radar, which is about 10 times higher than that of normal pulse type radar. The radar has enough sensitivities for faint clouds at high altitude and has high resolution in Doppler measurements. Using the millimeter wave radar we observe various clouds, and especially clouds with rapid changing phenomena such as heavy precipitations, violent winds, and so on. We can make rapid scanning observations of clouds with the radar. These result with scanning imaging reveal some important information of clouds and precipitations: dynamic motions of cloud interior, production of large droplets of precipitation in high altitude up to 10 km in cumulonimbus, sudden acceleration of precipitation after falling from bottom of clouds, and so on. These facts show that the facility is quite useful for environmental monitoring on clouds and precipitations.