Experimental verification of passive radar space object detection with a single low-frequency array radio telescope

Abstract

The paper focuses on the results of experimental research on the possibility of passive space object detection using a single radio telescope from the European Low-Frequency Array (LOFAR) network of astronomical radio telescopes. Commercial digital television (DVB-T) transmitters were used as illuminators of opportunity in this radar system. In the conducted experiments, one LOFAR radio telescope served both as a surveillance receiver and reference receiver in a passive radar system. The greater part of the LOFAR telescope array was used to observe a space object, while a small part of the array was directed towards the illuminator of opportunity to record the reference signal. One of the most important problems to overcome with utilising the LOFAR radio telescope in such a solution was the effective suppression of the direct-path component in a surveillance signal coming from the illuminator of opportunity, which was relatively close to the LOFAR radio telescope. The results regarding the passive detection of the International Space Station, included in the paper, confirm the possibility of observing the space object flying in Low-Earth Orbit using the LOFAR telescope or another receiving system with a similar antenna array.