Study On Optical System Of Multi-band All-sky Airglow Imager

There are various complex physical,chemical and dynamic processes in the adjacent space,which have an important impact on climate change and human space activities,and are closely related to human survival and development.The exploration of the earth's space environment is of great significance not only in science,but also in politics,economy and national defense.Air glow is one of the main tracers in the space atmosphere,and plays a very important role in the study of the earth's space atmospheric environment.All-sky airglow imager is an important space environment detection equipment.Its advantages are: all-sky imaging;multi-band detection;high temporal and spatial resolution;no focus;low cost.Airglow radiation carries important photochemistry and dynamics information.The characteristic spectral information of airglow(OH,O2,OI,Na and other airglow radiation bands)can be obtained by airglow imager,and the information of temperature,pressure,density and horizontal wind field in the upper and middle atmosphere can be retrieved.In this paper,the optical systems of two different kinds of all-sky glow imagery in 427.8-865 nm band are studied.Firstly,the research background,significance,history and current situation of all-sky airglow imaging are introduced in detail.The working principles of several airglow imaging devices which are widely used in the world are introduced.Three stages of the development of airglow imaging devices are summarized.The advantages and disadvantages of existing airglow imaging devices are compared,and the purpose and main contents of this paper are introduced.Then the parameters of the system are analyzed,including the determination of the focal length of the system based on the principle of non-similar imaging with fisheye lens.The conversion relationship between atmospheric glow intensity and illumination and luminance is deduced to analyze the parameter relationship between glow intensity and system F/# and exposure time.The important and common spectral lines of airglow radiation are summarized.The corresponding information of radiation source,reaction process,emission height and intensity are given.The basis for selecting detector and filter is determined.In order to reduce the cost of the system by eliminating the focusing device,a modified formula for calculating partial dispersion and Abbe number is proposed,and the matching of the complex achromatic glass suitable for the working band of the system is calculated.After determining the system parameters,the traditional all-sky airglow imager is analyzed,and two kinds of airglow imager systems are summarized and proposed.On this basis,the design of image telecentric fisheye lens is completed.The design of two kinds of all-sky airglow imager is completed.The imaging quality of the two structures was compared.The requirements of the two structures for the shape tolerance and the shape tolerance of the filter are compared.Finally,the system construction based on finished lens is proposed,and some matching schemes of commercial lens are listed.The system based on finished lens is simulated in software,and the feasibility of the scheme based on finished lens is analyzed.