Development of a low-power high-sensitivity cloud profiling FM-CW radar at 95 GHz

We developed a low-power and high-sensitivity cloud profiling radar transmitting frequency-modulated continuous waves (FM-CW) at 95 GHz for ground-based observations. Millimeter waves at 95 GHz are used to realize high sensitivity to small cloud particles. An FM-CW type radar realizes similar sensitivity with much smaller output power than a pulse type radar. Two 1 m-diameter parabolic antennas, separated by 1.4 m from each other, are used for transmitting and receiving the wave. The direction of the antennas is fixed at the zenith. The radar is designed to observe clouds between 0.3 km and 15 km in height with a resolution of 15 m. Using the facility, test observations and long term campaign observations have been done. Results of observations show that the system can observe clouds of -30 dBZ at a distance of around 5 km, which is sensitive enough to observe various kinds of clouds.