Advanced RAIM for Mega-Constellations

We describe a practical method to enable advanced RAIM in mega-constellations, where the number of ranging sources and the fault rates could be very high (thus rendering standard approaches potentially impractical). The method is based on a combination of a branch-and-bound approach and on the Gershrogin circle theorem. We evaluate the performance of ARAIM in mega-constellations for fault rates that would be unfeasible with standard RAIM and ARAIM approaches. We find that for constellations where 100 to 200 satellites may be in view for a user, the proposed approach would enable the computation of finite and useful Protection Levels with fault rates as high as 10^-2 per hour.