Auroral radio emissions observed at harmonics of the electron cyclotron frequency (boxed in top panel).
Direction of arrival resolved using 17-antenna array at Sondrestrom (contour plots with ISR radar scans superposed).
ISR scans through the emission meridian allow determination of the source region via wave tracing.
Electron density and magnetic field conditions in the source region were found to be critical inputs to the theory explaining the emissions.
THughes, J.M., J. LaBelle, and J. Watermann, Statistical and case studies of auroral roar observed with a medium frequency interferometer, J. Geophys. Res., vol 106, p 21147, 2001.
Hughes, J.M., and J. LaBelle, Joint incoherent scatter radar/medium frequency interferometer observations of auroral roar, J. Geophys. Res., vol 106, p 21157, 2001.
Hughes, J.M., J. LaBelle, and M.L. Trimpi, A medium frequency interferometer for studying auroral radio emissions, Rev. Sci. Instr., vol 71, p 3200, 2000.