Long-Distance Bistatic Measurements of Space Object Motion using LOFAR Radio Telescope and Non-cooperative Radar Illuminator

The paper presents the concept and results of experiments devoted to verifying empirically the potential capability of long-distance space object observation by radar system employing an astronomical LOFAR (LOw-Frequency ARray) radio telescope and a non-cooperative radar illuminator operating in a VHF band. The large antenna array of one of the LOFAR radio telescopes was used as a surveillance receiver to collect weak echo signals reflected from space objects, while the reference signal was recorded by a simple software-defined radio receiver located near the radar illuminator. A dedicated object motion compensation procedure has been applied to detect high-speed space targets in low-Earth orbit. The results of the conducted experiments confirm the possibility of detecting space objects employing the antenna arrays used in the LOFAR radio telescopes and signals emitted by non-cooperative radars to illuminate space objects.