Beam structure of Jupiter's decametric radiation

Data from concurrent Voyager and earth-based observations demonstrate that the Jovian source A radio emissions are not correlated with Io's position and have a distinct cross-sectional shape. The recordings were made simultaneously at 21.811 and 21.860 MHz in 1979. Voyager 1 and ground-data exhibited 13 highly correlated storms, unlike the Io-B events. Correlations were also identified among storms measured by both spacecraft and the ground station. Start and end times and flux densities for the highly correlated storms were used to calculate the projected beam shape. The data matched predictions of a model of a storm emission beam envelope in the form of a curved sheet that corotates with the planet.