Faraday Rotation in Saturn Kilometric Radiation

Saturn Kilometric Radiation (SKR) is generated by unstable particle distributions along auroral magnetic field lines inside Saturn's magnetosphere. This type of auroral radio emission has been continuously monitored by the High Frequency Receiver (HFR) of the Radio and Plasma Wave Science (RPWS) instrument onboard the Cassini spacecraft between 2002 and 2017. While SKR is known to be circularly polarized when observed near Saturn's equatorial plane, it also shows elliptical polarization when observed from higher latitudes. Elliptical wave polarization in combination with a birefringent propagation medium (X- and O-mode) provides conditions for the Faraday rotation effect, which is visible as a rotation of the major axis of elliptical polarization as a function of frequency. We searched through the entire Cassini RPWS/HFR data set and identified 611 Faraday rotation events in SKR, each event lasting one to a few hours on average. Considering the 15 years of Cassini SKR observations, Faraday rotation is a sporadic phenomenon. We present results from a statistical visibility analysis and discuss the beaming geometry of SKR, thereby gaining insight into the magnetospheric regions near Saturn that are responsible for producing Faraday rotation.