Dsd variations on rain-rate estimate algorithms of x- band polarimetric radar and rainfall characterization in tropical environments using 2dvd, rain gauges and trmm data

Abstract

Data from NASA TRMM satellite and rain gauges, the rain rate per hour was studied. The comparison took place in San Juan, Puerto Rico; when the Tropical Storm Jeanne passed over the island of Puerto Rico. Natural variations in raindrop size distribution (DSD) were studied for X band radar from October 2004 to July 2005 and September 15 to 16 , 2004 in San Juan, Puerto Rico. Three types of estimators of rain rates were examined: A classical estimator R(ZH) and two polarimetric radar estimators R(KDP) and R(ZH,ZDR) . According to simulation results, the normalized errors (NEs) with respect data disdrometer of R(ZH),R(KDP) and R(ZH,ZDR) for all DSD samples in October 2004 to July 2005 data are 40.85%, 14.73%, and 15.83% respectively, while for the tropical storm Jeanne they are 23.39%, 9.35% and 14.53%. The results show that the estimator R(ZH) is the most sensitive to variations in DSD.