Space tether - radar data processing

Abstract

NASA conducted the Delta-PMG tethered satellite mission. It was conducted to verify the hollow cathode plasma source's ability to couple electric currents from each end of a long wire tether traversing the ambient low earth orbit ionosphere plasma Observations were obtained through a suite of sensors which included large ground based VHF radars. The goal of this thesis was to process the radar data received at the radar based in Hawaii to study disturbances in the Earth's ionosphere caused by the tether. After extensive analysis, unique radar returns were identified that were associated with the passage of the tether system through magnetic field lines threading the radar's field of view. These returns were interpreted as a plasma cloud propagating along a magnetic field line and reflecting back along another. This phenomenon produced dual returns with inverted Doppler frequency content.