Exploring The Electron Component In Incoherent Scatter From The Ionosphere

Abstract

Small thermally-induced fluctuation in the ionospheric electron density present a scattering cross-section, if probed with a radar frequency higher than the plasma frequency. This technique, known as the incoherent scattering from the ionosphere, is a well-established field of study now. Since the conception of this field of study in 1958, numerous theoretical and experimental efforts have led the way to the high precision ionospheric research we have today. The theory of the incoherent scatter is highly robust. Recent advances in the radar hardware and computing technology have made it possible to probe the ionosphere using the full extent of this theory. In the effort presented here, high spectral resolution incoherent scatter experiments have been used to, for the first time, fully understand the theoretical predictions concerning the electron component of incoherent scatter. The two resonance lines that constitute the electron component are called the gyro line and the plasma line, and are greatly affected by the presence of the earth’s geomagnetic field. The experiments described here present the first unambiguous measurements of the gyro line with high spectral resolution in the incoherent scatter spectrum. Plasma line experiments presented here show the existence of frequency gaps that were predicted in the early days of incoherent scatter theory, but never observed. High latitude plasma line measurements are presented here to show that using the plasma line technique, the gravity waves in the thermosphere can be detected. The intention here is to observe all the components of the incoherent scatter and apply them to understand ionospheric processes.