Dual Frequency Millimeter-Wave Radar-Radiometer System for Volume Imaging of Clouds

World-wide energy production is modifying the chemical composition of the atmosphere, which is linked not only with environmental degradation and human health problems but also with changes in the most sensitive parts of the physical climate system ¿ namely, clouds and aerosols. This project will develop a dual-frequency scanning radar/radiometer system designed specifically to test cloud model predictions. The proposed radar will operate in the atmospheric transmission windows centered at 35 and 95 GHz, and will provide high sensitivity and fine spatial resolution in a compact design. In addition, by adding a parallel radiometer channel at each frequency, the system will be able to estimate cloud liquid water content and correct the radar signal for attenuation. Phase I will focus on developing an antenna design that combines the high gain required for the radar section and the high beam efficiency needed for the radiometer channels. In addition, a high-performance digital-pulse-compression design, needed to detect non-precipitating clouds at distances up to 30 km, will be developed. Commercial Applications and other Benefits as described by the awardee: The dual frequency radar/radiometer design should be suitable for cloud volume imaging applications, and also would complement advanced weather radar software designed to incorporate a parallel radiometer channel.