Effect of the atmosphere on radio and radar performance

The lower atmosphere above the Earth´s surface is absorptive, dispersive and inhomogeneous and therefore plays an important role in radio communication and radar performance in the frequency range from VHF to millimeter waves. For most of the applications, the radiowave attenuation caused by the atmosphere is of primary importance due to its direct impact on received signals and thus on the overall budget of a communication system. At frequencies less than 10 GHz the effect of atmospheric precipitation is not significant. However, for frequencies in the millimeter and sub millimeter wave region the atmospheric precipitation causes significant attenuation. The effects of atmospheric scattering, dispersion and depolarization on radiowave propagation for terrestrial and space-to-Earth communication are discussed