In the first step, the available data had been processed with a resolution of 1 km2, yielding a matrix of 480x480 points, for every 7.5 min volume scan. Average fields show the distribution of the precipitation in terms of predominant areas of echoes exceeding 40 and 50 dBZ, respectively, as well as the diurnal variation, anomalies and the frequencies of occurrence. The mean frequency of areas exceeding 40 dBZ during January shows a concentration of storms located in a region north to north-west at about 100km range from the radar, while the frequencies in other regions are significantly lower. The areas exceeding 50 dBZ during January correspond to 33% of all rain echoes >15 dBZ. During the February months the intensity of rain and the number of days with rain reached a maximum.
Rainfall records from an automatic weather station, located in Botucatu, approximately 100 km south-east of the radar are being used for the validation of the rainfall estimated from radar data. The accumulated rainfall was derived by using three different Z-R relationships, viz., Marshall Palmer, Calheiros & Zawadski and Antonio. It is proposed to deploy statistical techniques to evaluate these three Z-R relationships under local conditions.