Performance of a Developed Low-Power and High-Sensitivity Cloud Profiling Millimeter-wave Radar : FALCON-I

Abstract

We have developed a low-power and high-sensitivity cloud profiling radar, named FALCON-I, transmitting frequency modulated continuous wave (FM-CW) at 95 GHz for ground-based observations. Millimeter wave at 95 GHz is used to realize much higher sensitivity than lower frequencies to small cloud particles. An FM-CW type radar realizes similar sensitivity with much smaller output power to a pulse type radar. Two 1m-diameter parabolic antennas separated by 1.4m each other are used for transmitting and receiving the wave. The direction of the antennas is fixed at the zenith at this moment. The radar can observe clouds up to 20 km in height with the range resolution of 15 m and the angular resolution of 0.2 degree. Simultaneous observations of FALCON-I and a pulse type radar, SPIDER, show good performance of FALCON-I. Sensitivity of FALCON-I is -32 dBZ in radar reflectivity factor at 5 km, which is only 3dB worse than that of SPIDER although its output power is 1/3000 to SPIDER. Ranging resolution of 15m is realized for FALCON-I, which is 1/10 of that of SPIDER. Using developed FALCON-I, we observed clouds in various regions and oceans in the last three years.