Abstract Low radio frequency experiments performed on Earth are contaminated by both ionospheric effects and radio frequency interference (RFI) from Earth-based sources. The lunar farside provides a unique environment above the ionosphere where RFI is heavily attenuated by the presence of the Moon. We present electrodynamics simulations of the propagation of radio waves around and through the Moon in order to characterize the level of attenuation on the farside. The simulations are performed for a range of frequencies up to 100 kHz, assuming a spherical lunar shape with an average, constant density. Additionally, we investigate the role of the topography and density profile of the Moon in the propagation of radio waves and find only small effects on the intensity of RFI. Due to the computational demands of performing simulations at higher frequencies, we propose a model for extrapolating the width of the quiet region above 100 kHz that also takes into account height above the lunar surface as well as the intensity threshold chosen to define the quiet region. This model, which we make publicly available through a Python package, allows the size of the radio quiet region to be easily calculated both in orbit or on the surface, making it directly applicable for lunar satellites as well as surface missions.

中文翻译：

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表征月球背面背后的无线电静默区以进行低频实验

摘要 在地球上进行的低射频实验受到来自地球源的电离层效应和射频干扰 (RFI) 的污染。月球背面在电离层上方提供了一个独特的环境，其中 RFI 因月球的存在而严重衰减。我们展示了无线电波在月球周围和穿过月球的传播的电动力学模拟，以表征月球背面的衰减水平。模拟是针对高达 100 kHz 的频率范围进行的，假设月球形状为具有平均恒定密度的球形月球形状。此外，我们研究了月球的地形和密度剖面在无线电波传播中的作用，发现对 RFI 强度的影响很小。由于在更高频率下执行模拟的计算需求，我们提出了一个模型，用于外推 100 kHz 以上的安静区域的宽度，该模型还考虑了月球表面上方的高度以及为定义安静区域而选择的强度阈值。我们通过 Python 包公开提供的这个模型允许在轨道上或地表上轻松计算无线电静默区的大小，使其直接适用于月球卫星和地面任务。