Modeling of the zones of the Earth surface illuminated by the directional patterns of active multibeam antenna arrays

Abstract

A kinematic model of the motion of a spacecraft (SC) constellation along circular orbits and an expression for calculation of the number of SCs required to completely illuminate the entire Earth surface with the visibility cones of the directional patterns (DPs) of onboard antennas are presented. A simplified procedure for construction of multiple footprints of partial DPs formed by multibeam phased-array antennas on the Earth surface has been developed. Expressions for calculation of the slant distance, the grazing angle, and zones of visibility of the Earth surface from the SCs at the normal and oblique incidence of the antenna beam have been obtained. Numerical examples and the respective graphic illustrations are given.