Study On Doppler Asymmetrical Spatial Heterodyne Interferometer System For Atmospheric Wind Field Detection

With the rapid development of aerospace technology and the wide application of atmospheric environment science,the information of middle and upper atmospheric wind field plays a vital role in our space activities and science and technology.In order to obtain the information of middle and upper atmosphere wind field,researchers at home and abroad have developed various detection systems.To examine the study of the "Doppler asymmetrical spatial heterodyne(DASH)interferometer" in the field of wind field detection in the middle and upper atmosphere.At present,the research in China is not in-depth and the theory is incomplete.The ground-based Doppler asymmetrical spatial heterodyne interferometer system is the first step in research and the solution is the most fundamental and urgent problem.Based on the research significance of middle and upper atmosphere,this paper carries out related research on the system design and experimental verification of DASH interferometer.The main work of this paper is divided into the following aspects:1.First of all,the purpose of the detection of the middle and upper atmosphere wind field was expounded.Since the detection methods of middle and upper atmospheric wind field is divided into active wind measurement,passive wind measurement,ground-based observation and spaceborne observation,this paper mainly described the passive wind measurement technology.Therefore,on the basis of discussing the measuring principle,advantages and disadvantages of such devices as Fabry-Perot interferometer,it is found that DASH interferometers can avoid their shortcomings based on their structure.To achieve a more cost-effective exploration of the middle and upper atmosphere.In addition,the development status of DASH interferometers at home and abroad is summarized.2.In this paper,the detection mechanism of DASH interferometer system for wind measurement was described,the characteristics and reaction mechanism of airglow were analyzed,the components and characteristics of three typical airglow were described,and the principle of selecting airglow as the target light source was pointed out.The Doppler effect of light as the basic theory of passive wind measurement technology is the basis and prerequisite of DASH interferometer system for wind measurement.In this paper,the general formula of optical Doppler effect was presented,the basic structure and principle of DASH system were introduced,and the basic principle of phase inversion for interferogram was expounded.3.This paper described the system design process of DASH interferometer.Firstly,the optimal optical path difference design,thermal compensation design and field of view extension design were carried out on the interferometer.At the same time,the measurement errors caused by thermal drift in the process of wind speed measurement were analyzed,calculated and corrected.The entrance optics system and exit optics system were designed and simulated.The simulation results show that the design results of the entrance optics system and exit optics system meet the detection results.On this basis,the key parameters of DASH interferometer,such as signal-to-noise ratio and etendue were calculated.Finally,based on the analysis of the external factors of the system,the influence of the system’s signal-to-noise ratio on the accuracy of wind speed measurement and the influence of stray light on the accuracy of wind speed measurement are discussed.4.According to the above design results,the experimental platform was built,and the experimental results were verified.The optical elements and active elements needed in the experiment were introduced,and the working principle of the wind speed simulation device was expounded,and the error analysis of the wind speed simulation device was carried out.The feasibility of indoor detection with krypton lamp as detection target was verified by building an indoor experiment platform,which laid a foundation for wind speed simulation verification.Through wind speed simulation experiment,the wind speed measurement results were within a reasonable range under the condition of no temperature control system.On the basis of laboratory experiments,the integration of Doppler asymmetrical spatial heterodyne interferometer was performed,and the outdoor ground-based observation experiment was conducted with night glow as the detection target.The corresponding interference fringes were obtained successfully,which verified that the design results of DASH interferometer system were reasonable,the signal-to-noise ratio and etendue of the system met the detection requirements,and proved the feasibility of DASH interferometer ground-based detection.Finally,through two groups of laboratory experiments,when the interference module temperature difference was 0.2 ℃,the corresponding average wind speed value difference was 10.8m/s.Considering the wind speed measurement errors generated by other devices,the experimental results were consistent with the error results caused by the offset amount in the thermal compensation design.At the same time,it was proved that the measurement error of wind speed could be controlled within a certain precision range under the condition of temperature control system.