Research On Key Technology Of Infrared Radiation Characteristic Measurement Of Medium And Long Wave Based On Ground Targets

The infrared radiation characteristic measurement of target is of great significance in civilian and military field,as well as in theory and practice.Such characteristic can select the band and performance of the system based on the detection target,provide basic spectral characteristic for classification and tracking,offer evaluation basis for infrared detection and stealth technology,enhance the ability of reconnaissance and anti-reconnaissance.It is widely used in forest fire detection,sea rescue,night vision investigation and missile defense.The infrared radiation characteristic measurement is to obtain the radiation image of the target using the imaging system,obtaining radiance and radiant energy characteristics through radiometric calibration,atmospheric correction and characteristic inversion.At present,the precision of the infrared radiation characteristic measurement is limited.In this paper,a complete set of radiometric methods is designed for improving the accuracy.In this paper,the infrared radiation measurement is mainly studied from both theoretical simulation and measurement experiment.A theoretical study is carried out based on the theory of radiation basis and influencing factors.A fast calibration method for infrared optical system calibration is proposed,the atmosphere correction method under the cooperative scheme is studied,in the meantime,we analyzed the results of radiation measurements by experiments.The main research contents and results are as follows:1.Band selection and technical route formulation.Based on the analysis of theoretical and actual measurement data,the optical system performance and the characteristics of different band detectors are studied,and the radiation characteristics of typical targets and backgrounds are analyzed.From the experimental point of view,the composition of the radiation measurement system is studied,and the technical route for the measurement of target infrared radiation characteristics is made:radiometric calibration,atmospheric correction,and target inversion.2.Radiometric calibration technology.In view of the different response times of the system under different integration time,the relationship between the output of the system and the integration time and the incident radiation is studied.A fast radiometric calibration method is proposed,which improves the accuracy of the model and achieves an error of less than 1%.Nonuniformity correction and absolute calibration of long wave detectors are carried out by using high accuracy surface source blackbody,and the correctness of the method is verified by experiments of the medium wave detector,which is under different background temperatures in a thermostat.3.Atmospheric correction technology.By using the correction software of atmospheric transmission and the real time correction method based on the blackbody,a cooperative scheme combining two methods is proposed,which can not only guarantee the practicability but also improve the precision,and the precision is improved by 10%.We use the atmospheric correction software MODTRAN to analyze the influence factors on the medium wave 3~5?m and the long wave 8~12?m,the influence factors include atmospheric absorption,aerosol scattering,and transmission distance in the imaging process.This paper studies the algorithm of retrieving aerosol thickness by the solar photometer CE318,the atmospheric correction and target inversion experiments were carried out on targets at different distances.In conclusion,the infrared radiation characteristic measurement of target proposed in this paper is feasible and effective,has certain significance and reference value to the study of the theory and experimental in the future.