Research On Key Technologies Of Target Infrared Radiation Characteristic Measurement And Calibration

Infrared radiation measurement is the most important technology to obtain the radiation characteristics and temperature distribution of target surface,detect and identify infrared targets and evaluate the infrared stealth effect of various targets.With the continuous improvement of military strength and national defense requirements of various countries,infrared radiation measurement technology is developing rapidly.However,how to make infrared radiation measurement system achieve higher measurement efficiency and ensure accuracy in various scenarios for various targets has always been the key problem of radiation characteristics measurement technology research.The errors of infrared radiation measurement system mainly include atmospheric transmission model errors,the influence of target imaging characteristics,and radiometric calibration errors.Radiometric calibration will be affected by detector response characteristics and environmental temperature changes.In this paper in-depth analysis principle of infrared radiation measurement model and measurement error sources,on the basis of conducting the infrared radiation measurement system response nonuniformity correction methods,radiation calibration method,internal stray radiation measurement and simulation method and target extraction and inversion method of gray level research,in particular,this thesis mainly completed the following several aspects:(1)The linear response model of infrared thermal imaging system is analyzed,the response relationship between target radiation input and system gray output is established,and the relationship is deduced and summarized by infrared imaging theory.Based on this model,a non-uniformity correction method considering the integration time is applied to reduce the non-uniformity of infrared image effectively.An efficient radiometric calibration method based on energy flow density is adopted to analyze the radiometric calibration accuracy of medium and long wave measurement system.(2)In view of the influence of ambient temperature change during radiometric calibration,the quantitative relationship between ambient temperature and internal stray radiation flux was established through the measurement method of internal stray radiation based on radiometric calibration,and a simulation model was established to verify it.The paper also analyzes the phenomenon of gray drift caused by the change of ambient temperature,deduces the function relation between the amount of drift and ambient temperature,and amends and compensates the actual measurement results.(3)Considering the radiation characteristics of the point target,the edge detection technology is introduced to obtain the edge of the point target image and realize the gray extraction of the target.On this basis,the inversion algorithm based on brightness invariance is applied to inverse the target radiance,and the measurement error of this method is analyzedBased on the research of infrared radiation measurement system measurement principle and method,this paper deduces and improves the above several key technologies of infrared radiation measurement,which has certain theoretical significance and practical reference value for the improvement and optimization of infrared radiation measurement method and measurement accuracy.