Wednesday 24 June 2026, by Corentin Louis
Space-based radio interferometers are envisioned to perform directional observations at frequencies below 10 MHz, where planetary auroral emission can be observed among many other science cases.
Among the several new challenges that come with a satellite swarm is the need for knowledge of the swarm topology and attitude, especially for autonomous instruments.
This paper presents an algorithm that acts as a star-tracker with bright radio sources, leveraging the imaging capability of a radio interferometer, which we call “Radio-Source Tracker" (RST).
We study the algorithm’s performance through simulations applied to the NOIRE concept in the kilometric wavelength spectral range (30 kHz – 1 MHz), but the technique can be extended to higher frequencies.
The source positions are recovered from images iteratively reconstructed with source subtraction. Pattern-matching is performed with a voting system implemented on geometrical parameters defined by triplets of sources. The radio sky in the operating spectral band is modeled by extrapolating observations of the sky at 50 MHz. The accuracy of the recovered swarm attitude is measured for different levels of noise in the interferometric visibilities.
We show that our algorithm can achieve an attitude knowledge error lower than 1 arcmin for a swarm scale of 100 km. We discuss the limitations and the requirements in terms of memory and computation capability.