Inverse Problem of parameters identification: Radar Weather Equation

Abstract. An attempt to fit the weather radar equation by using radar data of the Radar C band localized on Bauru, São Paulo, Brazil, in the operational center of the Institute of Meteorological Researches, IPMet/UNESP, is performed as inverse problem to identification of parameters. Several values empirical to the coefficients and from e – relation coefficients, i.e., the radar measurements and the rainfall rate values, have been purposed. The IPMet radar use the values determined by Marshal-Palmer (1948), , , for the stratiform rain. Paz et al (2009) use data from stratiform rain event to identify e parameters. This work repeats the same study including several rain events during 2001 year. First, a direct theoretical model relating radar return to rainfall rates measured from raingauge, is presented. Second, a sensitive analysis as the performed to test the influence of the parameters involved in the inverse method. The sensitive analysis allows for establish the application conditions of the method. Third, the inverse algorithm of Levenberg Marquardt used to retrieve parameters of the radar returns model is described and its application is discussed. The sensitive analysis allows for establish the application conditions of the method. Last, a evaluating of de method is provide, through using rainfall data and reflectivity measured to retrieve and parameters values. The study case confirms the utility of the proposed method and its efficiency to provide a better performance of the studied model.