In this study, we focus on the refraction of planetary radio emissions as they pass through the ionospheres of moons—electrically charged layers of the atmosphere—and develop a method to derive electron densities from their bending behavior. Conventional observation techniques have limitations in spatial coverage. To address this, we propose a new approach that simulates the radio wave paths through the ionospheres using computer-based ray tracing and inversely estimates the electron density. We are currently applying this method to derive the electron density distribution of Titan’s ionosphere using data from the Cassini spacecraft. Furthermore, in preparation for the upcoming JUICE mission, we are investigating the use of radio wave polarization (i.e., rotational direction) to improve the accuracy of the analysis.