Research On Multi-parameters Optimization Design And Evaluation Method Of Model-driven Infrared Imaging System

With the improvement of the battlefield demand,the performance requirements of infrared(IR)imaging systems are getting higher and higher.In the future development of IR imaging systems,it is difficult to satisfy the long-distance,high sensitivity,and high resolution simultaneously.The development of the third-generation IR detectors and optical systems provides the technical guarantee for the performance improvement of IR imaging systems:IR detectors with small pixels,large arrays,and digital readout integrated circuits(ROIC)improve the spatial resolution and the sensitivity;under the premise of the same volume and weight,optical systems with large F-numbers increase the operating distance.Therefore,the IR imaging system developed by coupling the large F-number optical system and the smallpixel digital IR detector will definitely improve the combat capability of IR weapons.In order to shorten the development cycle of the IR imaging system with the large F-number and the small pixel,it is necessary to establish model of the imaging quality of the full-chain(target-atmosphere-optical system-detector-ROIC)of the IR system to digital assembly.The research can realize the full digital multi-parameters optimization design and the battlefield performance prediction.Aiming at the development requirements of future IR imaging systems,the multidimensional signal transmission,conversion and coupling matching mechanism of the imaging system full-chain to the object space radiation field is theoretically analyzed.The degradation mechanism of the matching relationship between the optical system and the detector on the imaging quality of the IR system,the trade-off relationship between multiparameters coupling matching and system performance indicators,and the degradation mechanism of IR system imaging characteristics in complex environment are deeply studied.The key scientific and technological problems such as establishing the multi-dimensional signal conversion model for the IR system with the large F-number and the small pixel,coupling and matching design of the optical system and the detector for improving system comprehensive performance,multi-parameters automatic optimization of the model-driven IR imaging system,IR imaging feature generation of long-distance targets,performance evaluation of IR imaging system in complex environment are solved.The multi-parameters optimization design and evaluation method of the model-driven IR imaging system is proposed,the design and evaluation of the IR imaging system with long-distance,high sensitivity and high resolution is realized.The main research work is as follows:1.For the problem that the traditional IR system imaging model cannot accurately describe the features of the IR imaging system with the large F-number and the small pixel,the imaging quality degradation mechanism and modeling method of the IR system with the large F-number and the small pixel is discussed in this paper.Considering the influence of the matching coupling between the large F-number optical system and small pixel IR detector on the imaging quality of each dimension,the degradation mechanism of IR system imaging quality is analyzed from the energy conversion dimension,space dimension and noise dimension,and the multi-dimensional signal conversion model of the IR imaging system with the large F-number and the small pixel is constructed,which provides a theoretical basis for the design and the performance evaluation of the IR imaging system.2.As for the problem that the matching relationship between the optical system and the detector affects the IR imaging system performance,the trade-off design method of ?F/d for improving the performance of the IR system with the large F-number and the small pixel is studied in this paper.The influence of the matching relationship between the optical system and the detector on spatial resolution,sensitivity and comprehensive performance is analyzed theoretically.The trade-off relationship between ?F/d and the performance of the IR imaging system is deeply studied.Meanwhile,the key technical problem of improving the system imaging quality by ?F/d matching design is mainly solved.The trade-off design method of ?F/d for improving the comprehensive performance of the IR system with the large F-number and the small pixel is proposed.3.Aiming at the problem of multi-dimensional performance constrained by multiparameters coupling matching of the IR imaging system,the multi-parameters optimization design method of IR imaging system is researched in this paper.Based on each dimensional performance characterization method of the IR imaging system,the coupling relationship between multi-parameters and each dimension performance is deeply studied.The key problem of multi-parameters automatic optimization of the IR imaging system is solved.Additionally,the multi-parameters optimization design method for IR imaging system is proposed.Through the optimization design of CA-295 camera aperture,the rationality of multi-parameters optimization method is verified.4.Imaging feature deduction of the long-distance target is the premise of evaluating the IR system imaging performance in complex environments.To solve this problem,the IR imaging feature deduction method of the long-distance target is demonstrated in this paper.Based on the transfer process of the target full-chain IR imaging feature,the degradation mechanism of the long-distance target IR imaging feature is mainly analyzed considering the target radiation characteristics,working environment,spatial response characteristics,energy conversion features.Moreover,the accurate deduction method of the long-distance target IR imaging feature is proposed.Several out-field experiments are organized to verify the accuracy of the deduction method of the long-distance target IR imaging feature.5.For the problem that the IR imaging system with long-distance,high sensitivity,and high resolution is more sensitive to the environmental interference,the performance evaluation method of IR imaging system in complex environment is studied in this paper.Guided by the IR system full-chain imaging quality degradation model,the degradation mechanism of IR system imaging performance in complex environment is mainly analyzed.In addition,the performance evaluation method of IR imaging system in complex environment is proposed,and the performance prediction of IR imaging system in complex environment is realized.