Method of Measurement of Electron Energies and Other Data from Spectrograms of V.L.F. Emissions

Abstract

It has been shown that the detailed frequency-time shape of discrete very low frequency emissions from the exosphere can be closely fitted on the electron-cyclotron theory by suitably choosing the electron parameters. Additional support for the theory has since been obtained in the verification of its prediction. It is shown here that the fitting process can be reversed so that these parameters can be deduced from the observed spectrograms. These are: the energy and helical pitch of the emitting electrons, the field line which guides them, the instant of their passing through the equatorial plane, and the electron density of the medium. Nomograms are given allowing calculation of these with occasional use of a slide rule and simple arithmetic.