【作者】 何国经；

【导师】 张建奇；

【作者基本信息】 西安电子科技大学 ， 光学工程， 2008， 博士

【摘要】 随着新工艺、新结构和新技术的引入,影响新型红外成像系统性能的因素发生了明显的变化,针对以往典型性能评估方法和模型对这些新技术考虑不足或没有考虑的问题,本文从三个方面开展了针对新型红外成像系统的性能评估方法研究,以适应不断发展的新型红外成像系统性能评估的需要:(1)基于全数字仿真的成像系统性能评估。利用三维场景模型和红外成像系统模型,结合三维驱动引擎及显示交互技术,完成成像红外导引系统模型与三维场景模型的对接,建立了综合考虑目标-背景-大气-成像系统的全数字仿真模型,实现了基于数字仿真的红外成像系统性能评估;(2)基于客观TOD判别模型的成像系统性能评估。以人眼视觉系统的信号传递特性以及眼/脑系统信息处理特性为基础,结合三角形方向判别阈值法的特点,建立了用于替代观察者进行TOD测量的客观判别模型,开展了客观判别模型与观察者的对比试验。分析结果表明,在常用的角空间频率范围内,客观判别能够准确预测观察者对三角形样条方向的判别性能,可以替代观察者进行TOD曲线测量,从而实现更为准确的成像系统性能评估;(3)基于背景杂波度量的成像系统性能预测。首先结合红外成像系统的信号传输和处理过程,分析了背景杂波的本质与属性,以及背景杂波对红外成像系统目标获取性能的影响。其次,针对不同的杂波评估需求,建立了两种杂波度量尺度:基于结构相似度的背景杂波度量尺度以及基于CRLB的背景杂波度量尺度。开展外场测量试验,获取试验处理数据。试验结果分析表明,两种杂波尺度都与背景信号对目标探测系统的干扰有很好的一致性,可以用于ATR系统目标获取性能预测。更多还原

【Abstract】 With the development of electro-optical technology, factors that affect the performance of infrared imaging systems (IRIS) have been changed. Traditional performance characterization methods or models become insufficient for the novel IRIS since they only consider a few or even none of these factors. Hence, it is necessary to improve traditional performance evaluation methods to satisfy the performance evaluation of the novel IRIS. In this paper, the following works are made.(1) Digital simulation for IRIS performance evaluation. By techniques of 3D-engine-control and display-interrelation, the interface between the 3D scene model and the IRIS model is constructed. And the digital simulation system for IRIS performance evaluation is set up, which is all inclusive of the components involved in the signal transmission chain, including the targets, the background, the atmosphere and the IRIS. And then, IRIS performance evaluation is performed upon this simulation system.(2) Objective Triangle Orientation Discrimination (TOD) for IRIS performance evaluation. Based on the characteristics of signal transmitting and information processing of human eye/brain systems, and the mechanism of TOD method, an objective discrimination model (ODM) is constructed. Comparison experiments are held for TOD performance data of ODM and civilian observers. Experimental results show that ODM can predict the TOD performance of civilian observers well within the common used angle frequency range. Thus, ODM can be used for TOD measurements instead of civilian observers, which results in a better IRIS performance evaluation by eliminating the artificial influence.(3) Background clutter characterization for IRIS performance evaluation. Background clutter has been gradually developing into the limiting factor of IRIS targets acquisition performance. Thus, it is important to find out how and in which way clutter affects IRIS performance. Based on the procedure of signal transmitting and processing of IRIS, the nature and characteristics of background clutter are analyzed, together with the mechanism it affects IRIS performance. Then, two clutter metrics are developed for clutter quantification, which are the Target Structure Similarity Metric (CMTSSM) and the CRLB Metric. Characteristics of the two clutter metrics are analyzed. With real IR image data, experiments are held for the relation between the clutter metrics outputs and the Automatic Target Recognition (ATR) system performance. Experimental results show that the trends of the clutter level varying with the target range are in good consistency with those of the ATR false alarm probability, which indicates the proposed clutter metrics are strong predictors of the background clutter level and can be used for ATR performance evaluation.更多还原