A decentralized position observer for small-sat swarms exploiting GNSS and ranging measurements

We propose a decentralized Kalman-based filter for absolute localization within a general swarm of small-sats, combining standard GNSS with inter-satellite ranging measurements. Differently from a centralized approach, each agent is responsible only for its own state estimation, yet exploits information from the rest of the fleet. The proposed approach reduces the uncertainty on the absolute position of more than one order of magnitude if compared to the case of GNSS-only measurement. Results are provided by extensive Monte Carlo simulations.