Low earth orbit satellite constellations for local telecommunication and monitoring services

Low Earth orbit satellite constellations deserve several advantages with respect to geostationary platforms, i.e. lower costs for satellite development and launch, increased imaging resolution, as well as reduced power requirements and signal time delays. This research is concerned with low Earth orbit constellation design, based on an original method that uses a correlation function. All the satellites are placed in repeating ground track orbits, and two conflicting requirements are considered: the maximization of the maximum continuous coverage and the minimization of the maximum revisit time of a target area located on the Earth surface. A suitable way of determining the related optimal constellation configurations is based on avoiding overlapping between visible passes of distinct satellites. With this intent, an analytic expression can be derived for the correlation function, which is employed to evaluate the overlapping between visible passes. Then, an algorithmic search for the zeros of this function allows determining several constellation configurations with the desired characteristics. This heuristic method turns out to be a successful approach for constellation design, and several results are reported with reference to distinct repeating orbits and different regions all over the world