Propagation of wave-packets incident obliquely upon a stratified doubly refracting ionosphere

Abstract
Little attempt has so far been made to apply Appleton’s magneto-ionic theory to wireless waves incident obliquely upon the ionosphere. Actually the magneto-ionic theory in the form given by Appleton (1925,1932) and others (Nichols and Schelleng 1925; Breit 1927; Goldstein 1928) is only suitable for investigating vertical propagation in the ionosphere, and it is the object of this communication to develop a generalization of Appleton’s magneto-ionic theory capable of dealing conveniently with waves incident obliquely upon the ionosphere. A general investigation into oblique propagation of electromagnetic waves through a slowly varying doubly refracting medium has already been made (Booker 1936), and the ideas there developed will now be applied to propagation through the ionosphere of wireless waves of wave-length sufficiently short (less than a kilometre, say) to regard the medium as slowly varying.