Active rain gauge concept for moderate to heavy precipitation using W-band and S-band Doppler radars

Previous research studies have used multifrequency radar Doppler spectra to study different aspects of precipitation, and have demonstrated its utility as an accurate profiling raingauge method (Firda, 1999). Recently this concept have been used to retrieve the drop size distribution (DSD) and vertical air motion in rain using a dual-frequency cloud profiling radar system, operating at 33GHz (Ka-band) and 95GHz (W-band), will provide measurements over a wider dynamic range of rain conditions, extending the active rain-gauge concept to heavier rain rates. The use of the W-bandsignal will provide accurate measurement of the vertical air motion in rain. Considering the conditions of heavy rain in which case large nonspherical raindrops exist, the actual drop´s shapes will be corrected. Data will be processed as suggested by Firda et al., 1999. This research´s goal is to develop software to retrieve several cloud characterization parameters, such as drop size distribution and vertical air motion from collected data during November 2001 at the Cloud and Radiation Testbed (CART) site in Lamont, Oklahoma. Rain rate estimates, drop size distribution and the vertical air motion retrieval used to study the inner processes of rain will be presented.