Lunar satellites could anchor Earth's drifting GPS constellations

Researchers at the Shanghai Engineering Center for Microsatellites propose linking Earth navigation satellites with orbiters around the Moon to correct drift when ground stations fail. In a 60-day simulation with 24 BeiDou-3 satellites and four lunar ELFO orbiters, drift fell from 7.85 m to 0.35 m.

• Without ground correction, drift reached 7.85 m over 60 days
• Trajectory prediction cut drift to 0.6 m
• The joint Earth-Moon network reduced drift to 0.35 m
• Position error for the four lunar ELFO satellites was 2.26 m