Multiple Scattering Analysis Within Swarms of CubeSats Devoted to GNSS Reflectometry

The use of CubeSat swarms for GNSS Reflectometry offers a promising approach to improve Earth observation, however it introduces challenges regarding phase synchronization. Indeed, the dynamic positions of the CubeSats induce time-varying distances between satellites. To address this, a distributed antenna array configuration is proposed, and the Method of Moments is employed, accelerated by Macro Basis Functions and multipole expansions, to efficiently model mutual coupling within the swarm. The approach significantly improves computational efficiency while maintaining accuracy, making it suitable for quasi real-time application in digital twins. The analysis provides an order of magnitude of the phase shifts induced by the mutual coupling.