Improved Rain Attenuation Correction Algorithms for Radar Reflectivity and Differential Reflectivity with Adaptation to Drop Shape Model Variation

One important goal of the Collaborated Adaptive Sensing of the Atmosphere (CASA) Engineering Research Center is to observe and monitor hazardous weather events in the low troposphere (below 1 km) by deploying networks of small, low- cost radars with small antennas. The first generation of CASA radar networks with dual-polarization capabilities is being deployed in Oklahoma. To achieve good sensitivity with small antenna size, high frequencies (X-Band) are selected. It is well known that signals transmitted at such high frequencies suffer attenuation due to rain along the propagation path. This article describes improved rain attenuation correction algorithms which correct radar reflectivity (Z_h) and differential reflectivity (Z_dr.) through measured differential propagation phase (Phi_dp).