Measurement of Jupiter's decametric radio source parameters by the modulation lane method

Abstract

[1] In previously published works we have developed a model to explain the production of modulation lanes in the dynamic spectra of Jupiter's decametric emission. In this paper we use the model with newly available data to test the model and to measure emission source and beam parameters. Some of the data were wideband, providing for the first time the opportunity to verify the accuracy of the model in fitting the considerable lane curvature exhibited in such a case. Relatively precise measurements of the cone half-angle of hollow-cone beam and other source and beam parameters of Io-B radiation were also made possible by the wideband data. Narrowband data enabled us to measure for the first time the beam cone half-angle for non-Io-A radiation. The measured cone half-angles for the two sources were both within ∼2° or 3° of 60°. This measurement is consistent with the long-held idea that the sources Io-B, Io-A, and non-Io-A are due to the same rotating hollow-cone beam and that the only difference between the latter two is the intensification of Io-A radiation by the connection with Io in comparison with that of non-Io-A. We also measured the cone half-angle for S bursts and found it to be less than that of the much more common L bursts. Copyright 2002 by the American Geophysical Union.