A Novel Radar Remote Sensing Orbiting System Using Tethered Satellites

The objective of this paper is to analyze the performance of two concepts of stabilized tether satellite systems used as a platform for a distributed radar sounder. After introducing the methodology for describing the geometry of the systems and their characteristics in terms of radar sounder, their performance are compared with each other and with the current state of the art. The first architecture consists in a cross-track oriented tether satellite system, controlled, and stabilized exploiting the rarefied atmosphere of low orbit. The second one involves a tether satellite system controlled through gyroscopic stabilization, due to which a constant oscillation in the cross-track direction is guaranteed. By analyzing the nominal behavior of these two architectures, it is shown how they can have better performance for radar sounding missions than classical formation flying. Specifically, these are able to be adapted to perform multiple observations at maximum quality during the same orbit, overcoming several limitations of formation flying. Finally, the advantages and disadvantages of each configuration are studied, and their possible mission scenarios are discussed.