"CLEOPATRA project aims at developing a SW procedure able to simulate relevant weather phenomena as they appear to airborne weather radars, starting from a high level description of the weather phenomenon (scenario), up to obtain the polarimetric I/Q signals at radar output. Such data have to be used as input to processing system simulation software (outside the scope of the present work) to be developed as test bench to compare the performances of new improved weather detection algorithms with older ones.The following main issues will be considered: Meteorological modelling (scenario definition) Electromagnetic modelling (backscattering from hydrometeors) Weather radar modelling (including clutter, antenna effects etc)having in mind the goal of developing a new class of simulators, able to combine the description of the meteorological scenario at mesoscale level (typical of the environment simulators) with the capability of generating accurate time series of raw signals (typical of the microphysical simulators), while keeping complexity and computational effort manageable. The procedure shall be “validated” by referring at experimental data coming from a ground based weather radar."