RECOMMENDATION ITU-R S.1559 - Methodology for computing the geographical distribution of maximum ... ANNEX 1 - Algorithm for calculating geographic distribution of maximum epfd? interference levels caused by non-GSO systems 1 Introduction 2 Outline of algorithm 3 Symbols used 4 Calculation of intersection of GSO ground terminal antenna beam with non-GSO sphere 5 Calculation of non-GSO orbital parameters and times when satellite and beam intersection points (Qi) are co-loca... 6 Calculating longitude crossings for a given simulated satellite 7 Determining if an orbit crosses through the beam of the GSO ground station antenna 8 Determining the simulation time of a spacecraft crossing through the beam of the GSO ground station antenna 9 Example computation 10 Future work