LEO Constellations to Cover the Earth in One Rev

Constellations of LEO satellites are presented that cover the Earth (or a region below a specified latitude) in a single rev. These constellations are shown to be very nearly optimal in terms of maximum revisit time (as compared to optimized constellations in the literature). They are easily generated using tables and plots provided. In sharp contrast to typical coverage constellations that spread satellites evenly across the globe, these satellites are grouped into a localized formation that works together to sweep across the globe. Because the satellites are close together, they can generally be continuously crosslinked (even though they are in LEO orbit). This feature allows data collected by the entire constellation to be downlinked to ground sites whenever any one of the satellites is in view. The long crosslink string allows real-time data to be retrieved from remote or denied locations. In one example, two ground stations are used to provide nearly continuous, real-time downlink of data collected from all six satellites in a constellation as they cover the globe in a single rev. In addition, proximity of the satellites allows significant stereo (or higher) coverage.