Simulation Analysis Of Space Borne Ionospheric Airglow Imaging

Ionospheric environment is an important part of the solar terrestrial space environment.Ionospheric disturbance will have a huge impact on communication system,power grid system and positioning system.Therefore,understanding the ionospheric change regularities is of great significance to study the impact of ionosphere on human production and life.As a tracer of the ionosphere,the radiation intensity of airglow is related to the density of ionospheric components involved in the reaction.Therefore,the detection of airglow by airglow imager can estimate the characteristics of total electron content and ionospheric disturbance parameters.Airglow imaging is one of the effective ionospheric detection methods.At present,the detection of space-based ionospheric airglow in China is still in its early phase.In this thesis,the observation simulation analysis of space-based ionospheric airglow imaging is conducive to promote the design and development of space-based imager and parameter optimization.The main contents and conclusions of this paper are as follows:(1)the photochemical reaction of 630 nm airglow is analyzed and a simulation analysis method is designed to calculate the radiation intensity generated by the transition from ~1D state of oxygen atom to ~3P state in the ionosphere at night.The simulation results show that the 630 nm emission intensity reaches the maximum at an altitude of 250 km,which is in line with the expectation.The regional distribution result is consistent with the overall strength and trend of the measured data.The radiation intensity calculation model is reasonable.Based on different solar cycle and season,the global airglow intensity is simulated and the simulation results provide a basis for setting the detection index of the imager.(2)The simulation research of space-based imaging is carried out,including complete image chains analysis and signal-to-noise ratio analysis;the scanning imaging simulation combined with ionospheric disturbance and satellite orbit is carried out by using an imager with time delay integration(TDI)imaging mode and typical parameters.The results show that the typical airglow imager parameters can clearly observe the global scale structure of ionospheric airglow in high solar activity years,and the low latitude ionospheric airglow structure in low solar activity years.(3)The relationship between airglow intensity and electron content is analyzed for the first time.The temporal and spatial distribution of the ratio of radiation intensity to electron content is analyzed,and the preliminary law is summarized.The research results of this thesis provide theoretical support for space-based ionospheric airglow imager,and also provide theoretical basis for other airglow observation missions and imager parameter design optimization.