  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.
