Impact of clouds from Ka band to optical frequencies

This chapter reviews the impact of clouds on microwave and optical wave propagation for applications to satellite communications. The optical properties of the atmosphere are deeply affected by the concentration, size, and phase of atmospheric particulates. Fog and cloud particles modify the optical properties of the atmosphere, reducing its transparency. Clouds are made of small water droplets or ice crystals suspended in the air, which form after water vapor condensation or sublimation when the air is cooled. The only difference between clouds and fog is that in the latter case the process occurs close to the ground. Cloud type information is used by some statistical models to predict cloud attenuation, as we shall see later. Cloud microphysics deals with the properties of the elemental components of a cloud body, that is, liquid droplets and ice crystals. The microphysical properties of clouds are highly variable due to the complexity of the formation processes.