Radar and optical studies of the atmosphere.

Abstract

The research described in this thesis can be categorized into three main areas. The first area concerns the interpretation of observations of various atmospheric processes and phenomena. The focus here has been on internal atmospheric gravity waves and their manifestation in radar winds and in airglow intensities, but also includes investigation of atmospheric tides and planetary scale waves, D-region electron densities and collision frequencies, the aspect sensitivity of backscattering and partially reflecting regions of the atmosphere, Polar Mesosphere Summer Echoes and Mesosphere Summer Echoes, meteor trails, mesospheric temperatures, long period variations in airglow intensities, and Kelvin Helmholtz Instabilities. The second major area has been in the development of new experimental techniques and the validation of existing techniques for investigating the atmosphere. New techniques have included the dual–beam radar technique for measuring momentum fluxes, and radar Time Domain Interferometry and Hybrid Doppler Interferometry for use with multi-receiver channel Doppler radars. The Doppler Beam Steering technique in the presence of non-uniform and periodically varying wind fields has been investigated analytically, and various spaced sensor techniques have been investigated using a numerical model of atmospheric radar backscattering and by direct comparison with other techniques. The Sodium Lidar technique has been investigated through numerical model calculations and a solid state system is currently being developed. Finally, a major activity has been the development of new radars and radar subsystems. This has included the development of a modular Medium Frequency Doppler radar and a Medium Frequency Spaced Antenna radar, a variety of Stratosphere Troposphere / Mesosphere Stratosphere Troposphere radars, an Ionospheric radar, a Boundary Layer Tropospheric radar and an All-Sky meteor radar.