Modeling of radiowave scattering in the melting layer of precipitation

In this paper, a new melting layer model called melting layer with spheroidal particles (CFPS in French) is presented. The physical description of the melting layer and the method of scattering calculation used in this model are developed. Two important contributions are the nonmonotonous law for the axial ratio of melting particles and the scattering calculation, which is made by an exact method for a spheroidal particle with any size and any axial ratio. The CFPS model is validated with radar data at 3 and 35 GHz. Results of validation are shown in this paper. Two applications are discussed: the comparison between three other melting layer models (developed by the European Space Agency, Delft University, and Helsinki University) that run faster in time but involve limitations in particle size or particle shape and a radar data inversion process in order to better characterize the melting layer and to retrieve meteorological parameters