Modelling of EHF propagation in clear air

The paper demonstrates how to use a spectroscopic data base in various applications. The base was expanded for satellite-originated radio paths to include the treatment of the O2-MS Zeeman effect which is important for the height range from 30 to 120 km. It is noted that a major uncertainty remaining is the prediction of anomalous water vapor absorption that can reduce the transparency in the four EHF window ranges at high relative humidities, and which is accounted for by an empirical relationship. Computer calculations of atmospheric transfer characteristics were performed using numerical approximations for the cumulative behavior of slant paths. Results from these modeling efforts are presented and their implications to communication and remote sensing applications are discussed.