Sensitivity of FMCW 95GHz cloud radar for high clouds

Abstract

Studying the vertical structure of cloud is essenti al to make better atmospheric modelings for simulations of the global warming. Cloud observation requires very high sensitivity for radar. Although pulse radar is the mainstream of MMCR (Millimeter Wave Cloud Radar), FMCW radar has some advantages. FMCW signal has high spatial and time resolution, and enables high durability and cost-performance because all of the components are designed with semiconductor devices. The bistatic FMCW Millimeter Wave Cloud Radar created by Engineering of Radio Physics Laboratory at Graduate School of Chiba University is designed to have 20km detection range of reflectivity and doppler velocity. Using this radar, we observed on a research vessel "MIRAI" in large region on the Pacific Ocean and the Arctic Ocean. These long-term observations and other observatin on the ground show good sensitivity of the radar and suggests the possibility ofFMCW cloud radar.

BASTA: A 95-GHz FMCW Doppler Radar for Cloud and Fog Studies

“…To drastically reduce the cost of the instrument, a different approach can be envisaged: instead of transmitting a large amount of energy for a very short time period (as a pulse), a lower amount of energy can be transmitted continuously. This technology is known as frequency-modulated continuous wave (FMCW) (Ligthart et al 1986;Yamaguchi et al 2006;Huggard et al 2008;Sami 2009;Williams 2011). Such FMCW radars have been developed in the past for a wide range of applications, such as the characterization of ocean waves (Hauser et al 1992).…”

“…Such FMCW radars have been developed in the past for a wide range of applications, such as the characterization of ocean waves (Hauser et al 1992). Very few developments have been geared toward the characterization of clouds and fog (e.g., Yamaguchi et al 2006;Huggard et al 2008;Thies et al 2010). The main challenge of such a radar is to optimize the signal processing in order to compensate for the lack of power of the transmitter.…”