Passive Radar Imaging Based on Multistatic Combination of Starlink and OneWeb Illumination

This paper presents an approach for passive multistatic radar imaging exploiting both Starlink and OneWeb satellite signals in order to address some limitations revealed by the first experimental results of passive radar imaging exploiting these novel LEO constellations, which are also presented in this paper. With respect to Starlink constellation, full 240 MHz-channel signals were not persistently received during measurements. Furthermore, when received, these signals showed a predominantly pulsed structure, hindering the integration gain, and resulting in back-projected images with reduced signal-to-noise ratios (SNR). However, narrow-band pilot signals were persistently received during Starlink satellite passes. On the other hand, OneWeb satellites have been experimentally verified to provide a persistent wide-bandwidth illumination, but the satellite orbits result in persistent areas imaged with spatial ambiguities and very limited cross-range resolution. To address those limitations, the proposed multistatic approach, whose effectiveness is evaluated via simulated data, is based on back-projection for both narrow-band Starlink signals and wide-band OneWeb signals.