A Satellite Link Analysis Tool for a Portable Ground Station

The product of this research effort is a comprehensive and integrated software package for the analysis of digital satellite links. The system is designed to run on the IBM PC, and would be a useful addition to any portable ground station based on a compatible personal computer. The system performs three basic classes of functions: satellite orbital analysis, antenna gain pattern plotting, and link analysis. The first class of functions includes the computation of such quantities as velocity, orbital period, and coverage area for satellites in circular and elliptical orbits. The second class of functions is concerned with plotting the gain patterns for horns, helixes, parabolic reflectors, and phased arrays of dipoles. The last class of functions represents the major thrust of the system, and entails computing such items as the G/T figure of merit, received useful power, carrier-to-noise ratio, bit error rate, maximum data rate, and power margin. Inherent within this class are mathematical models for computing the attenuation due to rainfall and atmospheric absorption. The link budget itself appears as a color-coded display with two columns: one for the uplink path, and one for the downlink path. The user also has the capability to change certain key inputs, and then have the system automatically recompute the entire link budget with the modified data.