A METHODOLOGY FOR RAPIDLY EVALUATING THE PERFORMANCE OF SOME LOW-EARTH-ORBIT SATELLITE SYSTEMS

A top-down design methodology for LEO systems is illustrated by an exa mple. The considered service is data messaging over local areas. The d esign method is based on a three-level approach: mission objectives, c onstellation selection and network design, and technical studies. It i s shown that many alternatives are to be explored, and this requires a set of consistent and efficient simulation tools. The tools considere d in the paper are a rapid computation algorithm for in-view period de termination, and a discrete event simulation-module. These tools are s hown to provide the designer with means to rapidly select the appropri ate constellation and evaluate the network performance.,