Orbit determination by cued observation using correlator radio telescope arrays: System model and performance evaluation

• Published in: Acta astronautica Vol. 236; pp. 503 - 513
• Main Authors: Nosrati, Ryan (Hamed), Biswas, Sanat, Smith, Stephanie, Hayman, Douglas B.
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.11.2025
• Subjects: DOA estimation; Orbit determination; Radio interferometry; Radio telescope; DOA estimation; Orbit determination; Radio telescope; Radio interferometry
• ISSN: 0094-5765
• DOI: 10.1016/j.actaastro.2025.06.011

We study repurposing radio astronomy correlator arrays for orbit refinement of resident space objects RSOs in the context of space situational awareness (SSA). By developing a suitable near-field interferometry signal model, we derive a 3D multiple signal classification (MUSIC) estimator to estimate the right ascension (RA), declination (Dec), and range offsets, allowing for the refinement of the position vector. This refined position vector is then utilized in an extended Kalman filter (EKF) to determine the new orbit, leading to improved accuracy and precision. Drawing inspiration from the configuration of the Australia Telescope Compact Array (ATCA) and correlator, we develop an observation simulator to produce measurement vectors for observation scenarios of perturbed trajectories at geostationary orbit (GEO), medium earth orbit (MEO), and low-earth orbit (LEO) regimes. We apply the proposed system model and demonstrate that the state estimation error is significantly reduced, leading to more accurate orbit refinement. Furthermore, our experimental results for radio observations made by ATCA provide further evidence for the effectiveness of the proposed strategy. •Radio telescopes track resident space objects to contribute to situational awareness•New method determines satellite direction and range to refine orbital elements•Method proven effective across various orbital regimes and validated on real data.