Polarization of Low Frequency Planetary Radio Emissions

Planetary radio emissions are the signature of particle acceleration in the solar system magnetospheres. Their polarization is used as a proxy from which the radio source emission processes, the source region local properties, as well as the propagation processes can be derived. In the low frequency range (<10 MHz), where radio measurements can only be done from space, the measurement of the polarization cannot be decoupled from that of the direction of arrival of the radio wave. Goniopolarimetric inversion techniques have been developed for this purpose. Only ground-based observations can provide a sensitivity good enough for expecting to detection radio emissions from exoplanetary magnetospheres. If/when successful detection will have been obtained, the polarization properties of these emissions will provide unique constraints on the exoplanet's roation, magnetic field magnitude and tilt, and even orbit inclination.