Study On Abnormal Disturbed Incoherent Scatter Spectra In Ionospheric Heating Experiment

On the basis of ionospheric heating theory, the main investigations about theobservations of ionospheric heating experiments with incoherent scatter radar in thisdissertation are introduced as follows:First, the power spectra of incoherent scatter signal are summarized based on theelectromagnetic scattering theory of single electron, collective electron and continualmedia of plasma. And the Ohmic heating theory and the parameter decay instabilitytheory about ionospheric heating are reviewed.Second, two analysis software for VHF radar data，GUISDAP and RTG areintroduced. CMS VHF Data Analyzer, the program for dealing with incoherent scatterdata is presented.Third, the enhanced ion line spectra in summer ionospheric heating experimentsare investigated. The profile of enhanced ion line spectra is an asymmetricdouble-humped structure. We can infer that the profile should be composed of coherentsingle-peak echo and incoherent double-humped structure, and the coherent echo is thedominant part. The amplitude of disturbance is related to altitude，and the enhancementof echo power diminishes away from the disturbance center immediately. The altitude ofmaximum value of the echo power is step-dropped. According to the Doppler frequencyshift, the plasma drift away from the line of radar sight, and the average velocity isabout1km/s.Finally, the enhanced plasma line in the heating experiments is studied. During theheating period, the structure of abnormal spectra is a bright spot, and the altitude rangeis9km. The enhancement peak of plasma line spectra is several hundred times largerthan the normal level.