A computer model for estimating microwave propagation characteristics along Earth-space paths in the 1-100 GHz range

Abstract

One of the most important tools available to the satellite communications engineer is link bud et analysis. Link budgets are especially useful for predicting system performance and for experimentinkwith various system desi n tradeoff!.accurate knowledge of afl attenuation and noise sources is essential because they determine how much margin should be designed into the link iq order to prevent an outage. However most link budgets consider only a few of the numirous attenuation and noise sources which exist in a real link, and even then make on1 crude approximations.The ogjective of this study is twofold: to develop accurate mathematical models for all significant sources of attenuation and noise within a link and to integrate these models into a link budget'analysis software package which can run on a personal computer. The attenuation source model includes quantitative expressions for radome losses, atmospheric scintillation multipath fading, and atmospheric defocusingf as well as the attenuation due to clouds rain, and gaseous absorption. The noise source'model examives surface emissions atmospheric emissions man-made and exira-terrestrial sources, is well as the problem of sun outages.