Key Technologies Research On Improving The Measurement Precision Of Ground-based Infrared Radiometry Systems

With the rapid development of infrared technology and measurement and control technology,infrared radiation measurement technology emerged and flourished.The radiation brightness or radiation temperature distribution of various targets can be effectively retrieved via the measured infrared radiation characteristic information Thus,the recognition,detection,and various performance evaluations of the target can be implemented.With the continuous improvement of the military strength of countries all around the world,the requirements for infrared radiation measurement systems have been becoming highly efficient,high precision,and highly applicable.The ground-based infrared radiation measurement system undertakes the radiation measurement tasks of various targets.The radiation measurement precision of the ground-based infrared radiation measurement system largely determines the overall performance of the system.Due to the complexity of measurement experimental conditions and the diversity of targets,improving the radiation measurement precision of infrared imaging systems is an important research direction to achieve various target recognition detection and infrared performance evaluation.The error sources of the infrared radiation measurement mainly include the influence of the optical imaging system,the calibration error,the atmospheric transmission model error and the extraction error of the target infrared imaging characteristic information.Based on an in-depth analysis of infrared radiation measurement principles and sources of measurement errors,the article further studied the characteristics of infrared radiation and its key measurement technologies,and studied the response characteristics of infrared radiation measurement systems,radiation calibration technologies and infrared atmospheric transmission.The research on the correction technology and the infrared radiation inversion algorithm.The main research work completed in this paper is as follows1.In-depth study of the transmission and transformation process of infrared radiation in the imaging system,the response characteristic model of the infrared radiation measurement system is deduced.The response relationship between the target radiation input and the system gray output is established as well.Based on above theoretical model,a method for measuring the focal length of the optical system based on interference is proposed,which achieves a high-precision measurement of the focal length of the system.Then the response characteristic parameters of the infrared radiation measurement system is calculates theoretically.The above study provides theoretical support for the calibration technique of external field radiation2.A radiation calibration model considering the integration time and the transmittance of the attenuator was established based on the analysis of the influence of ambient temperature changes on the precision of radiation calibration.The time of radiation calibration was effectively shortened.The influence of gray temperature drift caused by ambient temperature fluctuations on radiation calibration was reduced.And the precision of system radiation calibration in the external field environment was improved3.A neural network-based non-linear atmospheric correction method is proposed based on the analysis of the existing infrared radiation correction methods The atmospheric transmittance and range radiation from the target to the infrared radiation measurement system were predict effectively.The improved correction precision of radiation transmission in the atmosphere further enhanced the target’s infrared radiation measurement precision4.A radiation measurement model on the integration time and the transmittance of the attenuator was established based on the research of the target infrared radiation inversion algorithm.The image threshold segmentation technology based on iterative method was used to extract the gray information of the target infrared image.And a point target gray model is established according to the size characteristics of the target imaging.A point energy radiance inversion algorithm based on energy conservation is proposed.The infrared radiation measurement precision of point targets was improve effectivelyIn this thesis,several key techniques of infrared radiation measurement are derived and proposed,based on the research of the measurement principle and method of ground-based infrared radiation measurement system with a large number of theoretical analysis and experimental verification.The existing infrared radiation measurement method is improved,and the precision of infrared radiation measurement is effectively enhanced.The research results of this paper have important theoretical significance and practical reference value for optimizing the infrared radiation measurement method and improving the system infrared radiation measurement precision.