1. Circular polar constellations providing continuous single or multiple coverage above a specified latitude;Adams;J. Astronaut. Sci.,1987
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3. Elliptical multi-sun-synchronous orbits for Mars exploration;Circi;Celest. Mech. Dyn. Astron.,2012
4. Long-term revisit coverage using multi-satellite constellations;Hopkins,1988
5. Quantization and symmetry in periodic coverage patterns with applications to Earth observation;King;J. Astronaut. Sci.,1976