Improving the Accuracy of Rain Rate Estimates Using X-Band Phased-Array Weather Radar Network

Abstract

To improve rain rate estimation accuracy of the networked phased-array weather radars (PAWRs) installed in Osaka and Kobe, Japan, we employ a rain rate estimation method using a sequentially varying radar reflectivity and rain rate (Z -R) relationship. To calculate the time variation in the (Z -R) relationship, the rain rate of the existing X-band radar network comprising four dual-polarization radars and the radar reflectivity factor of the PAWRs are used. The proposed method is compared with estimation methods using the Marshall-Palmer relationship and the attenuation coefficient (k). From the comparisons between the rain rate with the three different estimation methods and the rain rate of the rain gauges installed in an analyzed area, we discuss the estimation accuracy. From the comparisons, the proposed method shows significantly better performance than do the other two methods even when weather conditions include heavy or violent rain.