Ionosphere induced spatial Imbert Fedorov shifts

Abstract

The reflection and transmission of radio waves are two most common techniques used to study the ionosphere. Considering an electromagnetic wave with a finite diameter, however, displacements and deflections different from the predictions of geometric optics arise. In this paper, we investigate thru calculations one type of these shifts, the out-of-plane Imbert-Fedorov (IF) displacements, induced by the ionosphere on the reflected radio waves. We model the ionosphere as a simple collection of electrons moving in a uniform magnetic field and use the resulting dispersive expressions to calculate the corresponding IF shifts. Since the ionosphere is a dispersive medium, we consider three cases: (1) metallic, (2) dielectric and (3) epsilon-near-zero (ENZ) behavior of the layer. We determine that there exists non-zero differential spatial IF shifts for all the three cases and find that the maximum shift of up to 95 m occurs when the ionosphere acts like an ENZ medium. Finally, we show that these transverse shifts are measurable and discuss how these can be utilized as a potential tool to profile the ionosphere using reflected radio waves.