Signal Acquisition And Data Processing Of Narrow-field Airglow Imager

The ionosphere and thermosphere are the most important area to human's life in space weather,and they are also the primary site for the near site satellite.Airglow is a significant glowing phenomenon in the atmosphere of the Earth.The space and time distribution of the atmosphere are modulated by various atmospheric dynamics processes such as tidal waves,atmospheric gravitational waves and planetary waves,so it occupies a special position in the field of physical research.The plasma irregularities,called plasma bubbles,are one of the primary causes of ionospheric scintillations in the low-latitudes ionosphere,which is very valuable to study the ionospheric plasma bubbles.A wider range of plasma bubbles could be observed through airglow imaging,their structures,variation and motions could be derived by those pictures.As a new airglow imager equipment,the narrow-field airglow imager has a good application prospect by using the high-sensitivity CCD detection technology to realize the low light detection and it can also observe the weak night airglow.Because the airglow radiation is too weak to observe,so it should get a long time exposure to get its integral image,and the acquisition environment must be strictly controlled in the night.However,the current classic equipment is all-sky airglow imager,it has the ability of automatic acquisition and storage,but it is not flexible to control the acquisition time with manual set,which has brought unnecessary troubles.Therefore,this paper takes the narrow field airglow imager as a research platform,and uses its data acquisition technology as the research object,and finally designs a connection system with data acquisition,display and storage.(1)I has briefly introduced the mechanism of airglow imaging,including the airglow observation and the development of airglow imaging,and the important role of its observation has played in space science,then I describe the significance of airglow observation with plasma bubbles,and emphasize the necessity and importance of the research work in this paper.(2)The basic theory of airglow and plasma bubbles is introduced,including the formation mechanism of plasma bubble and its morphological characteristics in airglow imaging,as well as how to obtain plasma bubble information by airglow observation.In the end,I have introduced the narrow-field airglow imager which has been completed and devoted to acquisition.(3)To make the airglow operate circularly,I has designed a software to control it with automatic collection,storage and image display.The controlling interface includes the setting of the basic parameters of the camera(exposure time),acquisition mode and readout mode selection.For different acquisition mode,there will be different parameters to set,it will be specifically introduced in the fourth chapter.In this software,the most important function is that the camera could start acquisition and end it automatically with strict time control in the unattended observation station,it need to obtain the time of local sunrise and sunset to set the acquisition state,in order to get this quality,the astronomical formula to calculate the local function is embedded in the program.Besides,in order to improve imaging,the uniformity correction experiment was carried out for the whole imager system.Now the program is operated smoothly and it is under data acquisition stage.(4)A series of image processing was done after the analysis of airglow data.The processing mainly contains image enhancement,azimuth correction and projection images,and finally get the preprocessed image which can clearly identify the plasma bubbles.(5)The research work of this paper is summarized,and the improvement suggestions are given to the deficiencies.At the same time,a vision of the future development of the narrow field airglow imager is made.