Abstract：

  Orbits that present a periodicity on both ground track and solar illumination condition are considered. These orbits, referred to as Periodic Multi-SunSynchronous Orbits, allow cyclic observations of a celestial body in which the solar illumination varies regularly in each region to come back to the initial condition after a time interval which is multiple of the revisit time. Therefore, this solution meets all the remote sensing applications, concerning both planets and moons of the Solar System, that need repeated observations at different local times (e.g. reconstruction of daily trend of surface and atmospheric phenomena). In this context, single and multi-plane satellite constellations can be taken into account to improve the repetition of observation and the ground spatial resolution.
  Emiliano Ortore graduated in Aerospace Engineering (M.Sc.) and in Astronautical Engineering (M.Sc.) and pursued his Ph.D. in Aerospace Engineering at Sapienza University of Rome. He worked as a Research Assistant in the School of Aerospace Engineering and in the Centre of Research San Marco Project (Sapienza University of Rome) and is now Assistant Researcher in the Department of Astronautical, Electrical and Energy Engineering of Rome (Sapienza University of Rome). He is a Lecturer in “Earth observation services and related orbits” in the Master in Satellite Systems and Services (Sapienza University of Rome).