红外探测系统数字域TDI关键技术研究

发布时间：2018-05-01 11:03

本文选题：数字域TDI + 红外成像　；参考：《中国科学院大学(中国科学院上海技术物理研究所)》2017年博士论文

【摘要】：红外数字域时间延迟积分(TDI)探测器是近年来出现的一种新型的探测器。该探测器以第三代红外焦平面探测器为基础,将探测器光敏元产生的信号先经过模-数转换,然后再进行时间延迟累加,通过增加曝光积分时间的方式有效提高红外目标探测灵敏度。采用数字域时间延迟积分技术的红外探测系统,积分方式更加灵活,在天基弱小目标探测方面具有非常重要的应用。由于红外数字域TDI探测采用数字域时间延迟积分技术,使其在系统设计和信息处理等许多方面与传统的红外TDI探测有明显的不同。本文开展了数字域TDI探测器的特性研究和弱小目标探测领域的关键技术研究工作,并以国产红外数字域640×8TDI探测器为核心搭建了红外数字域TDI探测实验系统,验证了理论分析正确性及探测方法的可行性。论文系统介绍了红外TDI探测器的国内外研究及空间应用状况,建立了红外数字域TDI弱小目标探测的数学模型,详细分析了非均匀性、盲元及速度失配对弱小目标探测的影响,重点研究了TDI探测器的盲元检测与补偿方法以及非均匀性校正技术。论文着重研究了红外数字域TDI弱小目标检测时的速度失配问题,提出了一种速度失配率的检测方法,并探讨了在存在速度失配情形下实现弱小红外目标探测的可能性。论文通过理论分析,得到了数字域TDI成像系统的信噪比提高与积分级数的关系。论文提出了一种采用帧间交错补偿方式进行探测器盲元补偿的方法。论文建立了数字域TDI探测器的速度失配模型和过采样模型,指出了速度失配的本质,给出了速度失配的极限条件,针对全局曝光TDI探测器在应用中根据帧间成像关系和速度失配条件提出了计算TDI的概念。论文还给出了数字域TDI系统实验测试结果。论文主要创新点如下:(1)盲元检测过程中同样采用行列分别检测的方法进行探测系统的盲元检测,补偿过程中利用探测系统扫描成像特性,采用帧间交错补偿使盲元获得其瞬时视场内的真实响应。(2)给出了一种基于帧间匹配的速度失配量检测方法。利用该检测方法可以获得速度失配率,通过设置合适的数字域TDI积分级数,可以实现一定速度失配情况下的弱小目标检测。论文研究结果对红外数字域TDI探测器及其在红外高分辨率成像和天基弱小目标探测系统中的应用具有重要的理论指导意义。
[Abstract]:Infrared digital domain time delay integrator (TDI) detector is a new type of detector in recent years. The detector is based on the third generation infrared focal plane detector. The signal generated by the detector Guang Min is first converted by A / D, and then the time delay is accumulated. The sensitivity of infrared target detection is improved by increasing the exposure integral time. The infrared detection system using digital domain time delay integral technique is more flexible and has a very important application in the detection of space-based small and weak targets. Due to the use of digital domain time delay integral technique in infrared digital domain TDI detection, it is obviously different from traditional infrared TDI detection in many aspects such as system design and information processing. In this paper, the characteristics of TDI detectors in digital domain and the key technologies in the field of small and weak target detection are studied. The experimental system of TDI detection in infrared digital domain is built with 640 脳 8TDI detectors in domestic digital domain as the core. The correctness of the theoretical analysis and the feasibility of the detection method are verified. This paper systematically introduces the domestic and international research and space application of infrared TDI detector, establishes the mathematical model of infrared digital domain TDI dim target detection, and analyzes in detail the influence of nonuniformity, blind element and velocity mismatch on small and weak target detection. The blind element detection and compensation method of TDI detector and the nonuniformity correction technique are studied in detail. In this paper, the problem of velocity mismatch in TDI dim target detection in infrared digital domain is studied, and a detection method of velocity mismatch rate is proposed, and the possibility of small infrared target detection in the presence of velocity mismatch is discussed. Through theoretical analysis, the relationship between the improvement of signal-to-noise ratio (SNR) and integral series of digital TDI imaging system is obtained. In this paper, a method of blind detector compensation based on interframe interleaving compensation is proposed. In this paper, the velocity mismatch model and over-sampling model of digital domain TDI detector are established, the essence of velocity mismatch is pointed out, and the limit condition of velocity mismatch is given. In this paper, the concept of calculating TDI is proposed according to the imaging relationship between frames and the velocity mismatch condition in the application of the global exposure TDI detector. The experimental results of TDI system in digital domain are also presented in this paper. The main innovations of this paper are as follows: (1) in the process of blind element detection, the method of column and column detection is also used to detect the blind element of the detection system, and the scanning imaging characteristics of the detection system are used in the compensation process. A speed mismatch detection method based on inter-frame matching is presented for blind elements to obtain the real response in their instantaneous field of view by using interframe interleaved compensation. The velocity mismatch rate can be obtained by using this detection method, and the small and weak target detection can be realized under certain velocity mismatch by setting appropriate TDI integral series in digital domain. The results of this paper have important theoretical significance for infrared digital domain TDI detectors and their applications in infrared high-resolution imaging and space-based dim target detection systems.
【学位授予单位】：中国科学院大学(中国科学院上海技术物理研究所)
【学位级别】：博士
【学位授予年份】：2017
【分类号】：TN215;TP391.41

【相似文献】