| As the rapid development of infrared detection technology, there has been a significant interest in the infrared radiation characteristics of military targets. Such characteristics can provide evaluation basis for infrared stealth technology, offer physical characteristics of target and background for simulation of infrared system which is helpful for establishing an accurate mathematical models, and supply essential data for target detection, recognition and tracking. At present, more and more high-precision groundwork infrared imaging systems are widely used on the measurement of radiation characteristic of military targets. Traditional target’s infrared radiation characteristics measurement mainly adopts single-band measurement method, i.e. acquire target’s full-band radiation image through infrared imaging system, and then the apparent radiation characteristic of a target, the measured results can only show information as relative temperature distribution due to the influence of target’s emissivity and reflected environment radiation, which make the single-band measurement method show its limitations. This paper studies the radiometric calibration and single-band measurement principle of target’s radiation characteristic intensively, and aims at the theoretical limitation of single-band measurement, we propose to adopt dual-band measurement technology to measure target’s true temperature. By improving the traditional dual-band radiation characteristic measurement method,we propose the middle-infrared-based dual-band radiation characteristic measurement method which is suitable for military targets, and then based on analyzing the factors which influence the dual-band measurement accuracy, we propose several approaches to increase the accuracy of dual-band measurement. This paper finishes the job in six following aspects:(1) Deeply research on the technology of target radiation characteristic measurement and the non-uniformity correction method of the infrared imaging system, and the radiometric calibration model and measurement model of the infrared imaging system are established, and then a calibration model considering integration time is proposed, which can provide the reliable basic theory of dual-band infrared radiation characteristic measurement.(2) Deeply research on basic theory of dual-band radiation characteristic measurement, aim to the disadvantage of traditional dual-band measurement method and combine with the peculiarity of middle-infrared imaging system, we establish the model of dual-band characteristics measurement. Aim to low-middle target in long-distance, the dual-band ratios of calibration and measurement are derive based on the radiometric calibration of infrared measurement system, and a dual-band radiation characteristic measurement considering atmosphere and reflected environment radiation is proposed.(3) On the basis of the dual-band measurement model established in this paper, we analyze the influence of the radiometric calibration error, selection of the measure waveband, random noise in measurement image, atmosphere and uncertainty of target’s emissivity on the of dual-band measurement accuracy in particular, which can provide the theoretical support for improving the precision of dual-band measurement.(4) In order to increase the efficiency of dual-band calibration and measurement, we proposed a dual-band radiation characteristic measurement method based on simplified radiometric calibration method. By analyzing the effect of ambient temperature on radiometric calibration, we proposed an ambient temperature-independent dual-band characteristic measurement method, the influence of ambient temperature variation on dual-band measurement accuracy, ambient temperature-independent dual-band radiation characteristic measurement method to ensure the accuracy of target’s radiation characteristic measurement, avoid the influence of inconsistent ambient temperature during the calibration process and measurement process on dual-band radiation characteristic measurement, which can improve the environment adaptability of the dual-band measurement method.(5) Aim to the characteristic of infrared measurement image, we propose a pseudo color display method for infrared measurement image based on K-means clustering and CIE-94 color difference equation, which greatly improved the visual quality of infrared measurement.(6) Design a dual-band radiation characteristic measurement system based on a middle-infrared measurement system and two infrared filters. In order to avoid the problem that using a black body as target lacks universality, we design a gray-body simulation device. Finish the dual-band radiation characteristic measurement experiment of gray-body target in laboratory and temperature chamber, which can prove the validity of the dual-band radiation characteristic measurement methods proposed in this paper.This paper deeply researches the technology of middle-infrared-based dual-band radiation characteristics measurement and establishes a middle-infrared dual-band radiation characteristic measurement system, and a great amount of experiments for radiometric calibration and target’s radiation characteristics measurement are finished. The experimental results shown that the proposed dual-band radiation characteristics measurement method can measure the target’s true temperature, the absolute error of temperature measurement is less than 4 ℃ and the measurement accuracy of radiation intensity is higher than 10%. The dual-band radiation characteristic measurement method based on simplified radiometric calibration method can simplify the calibration and measurement processes of dual-band measurement. The ambient temperature-independent dual-band radiation characteristic measurement method can measure the target’s radiation characteristic in case of ambient temperature fluctuation during the calibration process and measurement process. The research achievements in this paper has a great theoretical significance and reference value for further research on target’s radiation characteristic measurement and the design of dual-band radiation characteristic measurement system.
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