Multi-objective optimization design of extended Walker constellation for global coverage services

Many efforts have been made to optimize Walker constellations for global or regional coverage and up to scores of satellites symmetrically arranged in order to provide efficient coverage. This paper presents an extended Walker constellation design method without the assumption of rigidly symmetric orbits for global coverage constellation. Firstly, optimization model of constellation design is set up. Then, the design is transformed into a multi-objective problem. A constellation optimization method based on multi-objective evolutionary algorithm is used to search the parameter space and provide a set of Pareto optimal solutions for both intermittent and continuous global coverage. Simulation results illustrate that tradeoffs can be easily made between system performance and decision maker's preference.