Satellite constellation design for continuous coverage: short historical survey, current status and new solutions
Аuthors
e-mail: yuri.ulybyshev@rsce.ru
Abstract
A short historical survey of satellite constellation design for continuous coverage is presented. Comparison results of the major types circular orbit constellations for continuous global coverage are described. A table classification of satellite constellations based on an interface between concepts «constellation type» and «coverage type» is proposed. New constellation design methods for the complex coverage are also briefly described. Two type of continuous coverage are considered. First, it is a traditional simple continuous coverage connected with a visibility points on the Earth’s surface. Second, it is a more complex coverage for arbitrary geographic regions. If implies that, at any time, the region is completely or partially within the instantaneous access area of a satellite of the constellation. The key idea of the methods is based on common two-dimensional maps of satellite constellations and coverage requirements. The space dimensions are right of ascension of ascending node (in an inertial space) and time. In the space, visibility requirements of each region can be presented as a polygon and satellite constellation motion as a uniform moving grid. At any time, at least one grid vertex must belong to the polygon. The optimal configuration of the satellite constellation corresponds to the maximum sparse grid. Algorithmic basis for the methods is modern computational geometry. As an example, satellite constellation in circular orbit for continuous coverage of full geographic region by a satellite from the constellation is presented. The methods are extended to design of MOLNIYA type elliptic orbit constellations. Kinematically regular elliptic orbit constellations for continuous coverage of geographic latitude belts is considered. An analysis method of single track constellations for continuous coverage of arbitrary geographic areas by a satellite from the constellation is described. As examples, satellite constellations on elliptical orbits with periods ~12 and ~24 hours are considered.
Keywords:
Satellite constellations; constellation design; continuous coverage; region coverage; MOLNIYA type orbitDownload