HR: 16:40h
AN: P54A-03    [Abstracts]
TI: High Spectral and Temporal Resolution Observations of Saturn Kilometric Radiation
AU: * Kurth, W S
EM: william-kurth@uiowa.edu
AF: The University of Iowa, Dept. of Physics & Astronomy, Iowa City, IA 52242 United States
AU: Hospodarsky, G B
AF: The University of Iowa, Dept. of Physics & Astronomy, Iowa City, IA 52242 United States
AU: Gurnett, D A
AF: The University of Iowa, Dept. of Physics & Astronomy, Iowa City, IA 52242 United States
AU: Cecconi, B
AF: The University of Iowa, Dept. of Physics & Astronomy, Iowa City, IA 52242 United States
AU: Louarn, P
AF: CESR, CNRS, Toulouse, 31028 France
AU: Lecacheux, A
AF: Observatoire de Paris, ARPEGES, Meudon, 92195 France
AU: Zarka, P
AF: Observatoire de Paris, ARPEGES, Meudon, 92195 France
AU: Rucker, H O
AF: Austrian Academy of Sciences, Space Research Institute, Graz, A8010 Austria
AU: Boudjada, M
AF: Austrian Academy of Sciences, Space Research Institute, Graz, A8010 Austria
AU: Kaiser, M L
AF: Goddard Space Flight Center, Code 695, Greenbelt, MD 20771 United States
AB: The Cassini Radio and Plasma Wave Science (RPWS) instrument is the most capable planetary radio astronomy instrument to have been flown to the outer planets. Among other attributes, it includes a wideband receiver with 10- and 75-kHz baseband modes as well as a high-frequency down-conversion mode tunable between 125 kHz and 16 MHz that provides very high resolution spectral and temporal observations of Saturn's radio emissions. This paper presents an initial survey of dynamic spectra of Saturn kilometric radiation acquired upon approach and the first orbits of Saturn. Based on these early observations of Saturn's kilometric observations, perhaps the most succinct description of the appearance of the emissions in dynamic spectra is highly variable. The emissions display upward and downward drifting features with bandwidths down to the few hundred Hz resolution of the instrument and drift rates up to a few kHz per second. At other times, the emissions are much more diffuse or continuous, showing little spectral structure on scales of 10 or 20 kHz. Some features show very sharp upper frequency cutoffs and indistinct lower frequency cutoffs, somewhat suggestive of a caustic effect. The dynamic spectral features provide insight into the sometimes highly nonlinear nature of the cyclotron maser instability believed to generate the emissions and various processes such as diffraction within and near the radio emission source which shape the radio spectrum.
DE: 5737 Magnetospheres (2756)
DE: 6954 Radio astronomy
DE: 2704 Auroral phenomena (2407)
DE: 2756 Planetary magnetospheres (5443, 5737, 6030)
SC: Planetary Sciences [P]
MN: 2004 AGU Fall Meeting