Passive Multistatic Localization of Space Objects using LOFAR Radio Telescope

The paper presents the idea and results of the experimental trials devoted to passive multistatic observation of space objects in low-Earth orbits employing an astronomical LOFAR (LOw-Frequency ARray) radio telescope as a surveillance receiver. Terrestrial commercial digital radio transmitters operating in the VHF band were used as illuminators of opportunity. The large antenna array of the LOFAR radio telescope allows us to record relatively weak echo signals reflected from space objects. Reference signals were acquired by software-defined radio receivers located near illuminators of opportunity. Combining the results of bistatic measurements from three pairs of illuminator-receiver, we estimated the position of a space object in a Cartesian coordinate system. The results of the experiments confirm the possibility of determination of the space object’s position utilizing the passive radar system using antenna arrays such as the array in the LOFAR radio telescopes and the commercial terrestrial transmitters as illuminators of opportunity.