Autonomous LEO-PNT System and Impact of Isoflux Navigation Antenna on Constellation

This work proposes an autonomous Low Earth Orbit (LEO) satellite-based positioning, navigation, and timing (PNT) system design independent of traditional GNSS infrastructure. The system features a compact navigation payload with redundant atomic clocks, a software-defined radio (SDR) for backhaul communications, and an isoflux-pattern antenna for uniform ground coverage and enhanced signal robustness. The results show that increasing antenna field-of-view (FoV) from 80 ◦ to 120 ◦ at 800 km altitude reduces the constellation size by a factor of five while maintaining four-fold global coverage. These findings suggest that optimized antenna and payload designs can enable cost-effective and resilient autonomous LEO-PNT capabilities.