Satellite Constellation Design Based On Genetic Algorithm

The development and growth of the earth observation, navigation and commu-nication during the past tens years has led to demand for and development of theseservices everywhere and over every possible medium. This includes the medium ofsatellite. During those same decades, the growth in use of satellite to provide a widely-available earth observation, navigation and wireless communications infrastructurehas led to the development of satellite applications using satellite constellation .A satellite constellation can be defined as a number of similar satellites, of asimilar function, designed for a certain purpose. Satellite constellation is a basalform for a group cooprating satellites.Traditional satellite constellation design has focused on optimizing global or zonalcoverage with a minimum number of satellites. In fact, in this case, the analysis ofthe configuration, based on circular orbits and uniform distribution of orbital planes,allows, because of the symmetry, to develop manageable analytical models. Notwith-standing, in some specific issues (i.e. regional coverage or hybrid orbit typies), eccen-tric orbits should be preferred for the coverage of restricted areas.Furtheremore, satellite constellation designers are rarely concerned with optimiz-ing performance with respect to a single objective such as earth coverage. Rather,multiple competing requirements drive the design.The genetic algorithm (GA) has been introduced as a robust technique to solvemany multivariable problems. The multiple-objective GA (MOGA) is used to solvethese problems because the multiple-objective optimal design is suited for problemswith large number of variables. MOGA for Walker satellite constellation and for zonalcoverage area is also introduced.Based on the analysis of the technology challenges for satellite constellation de-sign and the limitation of related work, this dissertation focuses on satellite constella-tion design optimized by GA and MOGA. The major contributions of the dissertation include:Considering the capabilities of GA and MOGA, the dissertation proposed ageneral 6N constellation model based on the analysis of some known constellationmodels. The general 6N constellation model parameters consist of all 6 orbitelements of every satellite. So the 6N model includes all known and unknownconstellation types. Constellation designers should select a constellation typefirst using traditional method. But the constellation designers could not seemto agree on the best approach to select the'best'constellation type for the sametask. The general 6N constellation model is foreign to constellation type, andsuits most satellite constellation design applications.The dissertation presented a improved satellite constellation design method basedon GA. Considering the earth observation, satellite navigation and satellite com-munication constellation design tasks, an one-up MOGA called the nondomi-nated sorting genetic algorithm 2 (NSGA-II) was used for a uniform constellationdesign algorithm model. Besides earth coverage, the uniform constellation de-sign algorithm model includes some basal system performance evaluation rulesfor earth observation, satellite navigation and satellite communication, whichcan be modified or added by constellation designer considering their own taskrequest.The dissertation analysed the characters of earth observation, satellite naviga-tion and satellite communication, proposed reasonable performance evaluationapproaches for vary satellite constellation systems.Some optimum satellite constellations, which better than the same task constel-lations in some publication, were demonstrated the the advantages of satelliteconstellation design method based on GA and MOGA for earth observation,satellite navigation and satellite communication.