Research On The Infrared Atmospheric Visibility And Engineering Application

With the continuous development of infrared technology and been widely used in military and civilian fields, the research of infrared radiation transmission in the atmosphere is becoming more and more important. Atmospheric transmittance of infrared radiation has an important impact on the design, performance evaluation of infrared opto-electric systems (such as tracking system, search system, warning system and thermal imaging system, and so on).Since the complexity of the atmospheric compositions and the atmospheric states changed by meteorological conditions lead to the atmospheric attenuation characteristic of the infrared radiation is complex, in the bad weather, the main restrict factor of associated applications is atmospheric. Therefore, researching on the impact of atmospheric on the infrared system operating distance has a very important practical significance for infrared engineering applications.The operating distance of infrared system is the index of the traditionally infrared system detection capability, and mainly decided by the target and atmospheric transmittance, optical system, detector and signal processing four parts performance. It reflects the relationship between the infrared system operating distance and various components of the infrared system, however, for engineering users, the optical system, detector and signal processing are fixed quantity, and the only varying factor of the infrared system is atmospheric transmittance in different applications. At present, analysis of the definition, algorithm and influencing factors of the infrared atmospheric visibility have not been reported, under the strong demand of infrared electric engineering applications, this paper propose an innovative definition of the infrared atmospheric visibility, used to characterize the effect of atmospheric on the infrared system operating distance. The concept of the infrared atmospheric visibility had being puts forward on the basis of referencing the definition of the visible light atmospheric visibility, analyzing of key decision factors of the infrared atmospheric visibility in the atmosphere, and establishing the quantitative relationship between infrared atmospheric visibility and these factors according to the physical processes of atmospheric radiation transmission.The main contents and innovations of this paper:(1) Only analysis the effect of atmospheric condition on infrared system operating range, without regard to the feature of infrared system, such as the optical system, detector and signal processing, and so on. It is the first time to present the concept of infrared atmospheric visibility to characterization it.(2) Established the quantitative calculation model of infrared atmospheric visibility according to the physical processes of atmospheric radiation transmission. Systematically analysis of the factors that affect the infrared atmospheric visibility, mainly factors that are:the visible light atmospheric visibility, water vapor content, aerosol types; secondary factors are:the solar zenith Angle, observation azimuth, etc.The research and achievements of the paper have a significant value for quantitative evaluation, analysis of the impact of atmospheric effects from the infrared system.