Evaluation Of Ground Wave HF Emergency Communications Interference On Radio Astronomy Satellites On The Lunar Far Side

As humanity plans to establish a settlement on the Moon, ensuring reliable emergency communications for astronauts during extravehicular activities (EVA) becomes a critical requirement. Historically, the Moon’s unique position, blocking electromagnetic interference from Earth and the Sun, has been utilized for astronomical missions, particularly in low-frequency radio astronomy research, demonstrating the Moon’s potential as an electromagnetic shield. Therefore, the potential interference of HF ground wave communication in the far side of the Moon needs to be evaluated. Through my prior research, we have already demonstrated the feasibility of HF ground wave communication as an emergency communication method on the lunar surface.To assess the interference of HF ground wave signals from the lunar surface on radio astronomy satellites in lunar orbit, this study employs an improved Ott equation to simulate the propagation of HF ground wave signals on the lunar surface. Based on this, factors such as surface reflection and free-space propagation loss are incorporated to model the radiation of ground wave signals in the vertical direction for this scenario.We applied this model to actual lunar surface topography data from previous lunar exploration missions and evaluated the interference of these signals on radio astronomy satellites in lunar orbit. The results show that while ground wave signals can propagate over a certain distance, their intensity rapidly attenuates with increasing distance. By the time the signal reaches lunar orbit, its strength is well below the receiver sensitivity threshold of the radio astronomy satellites. Even under the most unfavorable communication conditions, the ground wave signal does not cause significant interference with the satellite’s normal operation.This study not only provides theoretical support for the emergency communication plans of future lunar settlements but also ensures the continuity of radio astronomy observations on the lunar far side. Additionally, the findings help in the planning of wireless communication networks on the lunar surface and offer valuable insights for the establishment of settlements on other celestial bodies, particularly in managing electromagnetic environments in areas interacting with astronomical observations.