Precipitation is one of the most variable atmospheric parameter in space and time. It influences the dynamics of the earth s atmosphere. Three-fourth of the energy that drives atmospheric circulation is generated from the latent heat released by the precipitation. Precipitation has many applications in agriculture, hydrology, flood predication, water management and climatology. Despite its importance, precipitation is one of the most difficult atmospheric parameters to measure because of its large variability in space and time. Many investigators have focused upon getting better rainfall...