Model for Computation of Interference to Radio-Relay Systems From Geostationary Satellites

Terrestrial radio-relay systems operating in the 4-GHz and 6-GHz bands share these frequencies with communication satellite systems, and additional bands may be designated for shared usage. In the future, as the geostationary orbit occupancy increases, coexistence of these systems will be possible only if controls are imposed on both systems. Presently, the International Radio Consultative Committee (CCIR) recommends1 that radio-relay antennas, radiating frequencies normally received by satellites, maintain a specified angular separation with respect to the geostationary orbit or, where this is not practical, the application of power limitation to the terrestrial transmitters. They further recommend2 that satellite power flux density be limited as a function of the angle of illumination at the earth's surface. The pointing restriction is intended to protect satellites from terrestrial systems. Methods have been devised3 for calculating beam-orbit separation as a function of azimuth displacement of the antenna from intercept, and 81