Publications Journal article · Mega-constellations · 2026

RF-Assisted Compensation for Rapid Optical Acquisition in Hybrid Inter-Satellite Links

Elena Fernández-Niño, Juan A. Fraire, Adriano Camps, and Joan A. Ruiz-de-Azua

IEEE Open Journal of the Communications Society, vol. 7, pp. 6625–6639, 2026

Abstract

Establishing Optical Inter-Satellite Links (O-ISLs) requires sub-degree pointing accuracy between fast-moving satellites, a challenge resulting from actuator limitations and positioning uncertainties. This work proposes a novel pointing strategy for Hybrid Inter-Satellite Links (H-ISLs), i.e., combining Radio-Frequency (RF) and Optical technologies, to maximize usable contact time. The strategy leverages TLE-based pre-pointing executed before the line-of-sight contact to eliminate the actuator-induced transient regime from the contact window. Once the RF-ISL is established, satellites exchange updated GNSS data to refine pointing accuracy, which narrows the initial optical uncertainty cone. This shortens the optical spatial-acquisition time and increases the effective transmission time of the O-ISL. The approach is evaluated under a realistic LEO-based scenario incorporating actuator dynamics and degraded TLE updates. Results show that the initial pointing error (ideal vs. commanded slew) is reduced from 167 degrees to less than 2.5 degrees, the effective optical transmission time increases from 72% to over 99%, and the memory buffering requirements drop more than 98%. This work demonstrates the feasibility and performance benefits of RF-assisted pre-pointing in smallsats’ O-ISLs.

Cite

DOI 10.1109/ojcoms.2026.3688693

BibTeX

@article{fernandez2026rf,
  author    = {Fern{\'a}ndez-Ni{\~n}o, Elena and Fraire, Juan A. and Camps, Adriano and Ruiz-de-Azua, Joan A.},
  title     = {{RF}-Assisted Compensation for Rapid Optical Acquisition in Hybrid Inter-Satellite Links},
  journal   = {IEEE Open Journal of the Communications Society},
  volume    = {7},
  pages     = {6625--6639},
  publisher = {IEEE},
  year      = {2026},
  doi       = {10.1109/ojcoms.2026.3688693}
}

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