Observations of the First Harmonic of Saturn Kilometric Radiation During Cassini's Grand Finale

Clear first harmonic emissions of Saturn Kilometric Radiation are discovered during the Cassini Grand Finale orbits. Both ordinary (O) and extraordinary (X) mode fundamental accompanied by X harmonics observed. Analysis shows that frequency ratio between is 2.01 ± 0.08, display weaker intensities than fundamental, 30–40 dB for X-X (fundamental-harmonic) type 10–30 O-X harmonic. The intensity relations two types harmonics, is, show different patterns we attribute to conditions emission at source. Direction-finding results plausibly generated in same source region. In agreement with previous studies Earth, generation can be attributed cyclotron maser instability operating plasma density electron energy distributions