Radio Propagation Measurements of Auroral Ionization Using Rocket-Borne Transmitters

Abstract

Three rockets carrying radio propagation experiments were launched respectively into the prebreakup, breakup, and postbreakup phases of auroral displays during early 1968. The radio measurements, which provide information concerning the three-dimensional spatial gradients in ionization, show quite different characteristics for the three occasions. In the first two it seems that the configuration of ionization was essentially similar to that of the visible aurora. In the third, during a widespread homogeneous auroral glow, the ionization showed weak small-scale irregularities, possibly generated locally by plasma instabilities. Data from a ground-based photometer and from particle precipitation experiments aboard two of the rockets are also compared with the radio evidence.