Lunar Transfer Orbit Navigation Augmentation Via Surface Beacon: Reimagining LuGRE

This study investigates navigation performance improvements enabled by integrating a Lunar Radio Beacon (LRB) with multi-constellation Global Navigation Satellite Systems (GNSS) in cislunar space. A parametric simulation framework combines measurement characteristics from the LuGRE payload aboard Firefly's Blue Ghost Mission 1 (BGM1) with an extended Space Service Volume (SSV) simulator. Signal availability, Geometric Dilution of Precision (GDOP), and single point positioning performance are analyzed for GNSS-only and LRB-augmented configurations across multiple constellations. Results demonstrate improved geometric observability and positioning performance when observables from a surface-based beacon are included, supporting the role of lunar radio beacons in future cislunar navigation architectures.