Cloud liquid models for propagation studies: Evaluation and refinements

The Salonen cloud model currently in use in propagation and remote sensing simulations is analyzed at two independent sites: the ARM SGP site in USA, and the FUB site in Pomezia, Italy. The humidity threshold function is evaluated by using a ceilometer located at SGP and an otimization of such threshold is proposed. The cloud water model is assessed by comparing simulated brightness temperatures (TBs) with those measured by a dual-channel radiometer at 23.8 and 31.4 GHz. At SGP, the Salonen model is also tuned to the radiometer TBs. Then, the Salonen model, its modifications, and a model developed based on the outputs of numerical simulations are all evaluated at the site of Pomezia, in Italy, by comparing simulated TBs with measurements from a dual-channel radiometer at 23.8 and 31.65 Ghz.