变阈噪比优化机载IRST系统的探测概率包线

基于机载红外搜索跟踪(IRST)系统噪声源的特点,建立了一种探测概率模型,分析了探测过程中阈噪比对探测概率、虚警概率的影响。基于作战背景,分析了探测距离、目标速度、作战环境对探测概率的影响。在探测过程中动态设置阈噪比,给出了具体求解方法,并对不同任务需求下的阈噪比取值范围进行仿真分析。利用求解的阈噪比值,仿真得出了变阈噪比情形下的探测概率包线。研究结果表明,与恒定阈噪比方法相比,采用变阈噪比求得的概率包线能够适应实时变化的空战条件,普适性更强,探测距离明显增大。     

扫描型热像系统均匀性校正方法研究

随着热像系统时域噪声等效温差（NETD）的不断下降,残余固定图形噪声（RFPN）的不稳定性成为制约系统性能,特别是制约系统识别能力的一个关键因素。通过分析热像系统响应非均匀性产生的机理,介绍一种扫描型热像系统获得场景平均辐照度点的方法,实现了以场景平均辐照度点为校正基准点的动态校正。采用该方法研制的热像系统在（0～50）℃场景动态范围内可使系统的RFPN小于15mK。通过样机冬、夏两季外场试验以及各种环境试验,验证了该校正方法在热像系统温度发生变化以及场景辐照度发生变化时具有良好的适应性。     

生物光子图像的探测概率和极限

分析了生物超微弱发光的光子图像特点,从而看出对光子图像进行统计研究的必要,讨论了生物超微弱发光的统计分布,分析了生物超微弱发光在光子成像系统中的探测概率和光子图像的探测极限。     

层叠微透镜阵列扫描成像系统的动态像差

以层叠微透镜阵列扫描成像系统的动态像差为研究目标,基于非旋转对称光学系统的矢量波像差理论,建立了层叠微透镜阵列扫描成像系统的动态波像差理论模型,提出一种可用于系统波像差计算的适用性方法。同时,将动态波像差模型应用于两片式微透镜阵列扫描结构的像差分析中,分析了多扫描视场下的初级波像差以及均方根（RMS）波前差,并计算了不同扫描视场下的初级波像差值在光学表面上的分布。所得研究结果对层叠微透镜阵列扫描成像系统的设计优化与装调实验具有理论指导和工程化意义。     

级联介质系统中多散射点形成热像的数值分析

 以5片带增益损耗的级联介质板为例,数值模拟分析了高功率激光器系统中,由垂轴平面内多个散射点形成热像的演化规律,讨论了散射点参数对散射光之间相互作用的影响。模拟结果表明：无论这些共面的散射点同时或分别单独存在,其形成的热像点亦共面,只是同时存在时对应的热像峰值强度比单独存在时低;当不同参数散射点引起的散射光在从背景光场中提取能量形成热像时,提取能量的竞争并不平等,最终会导致某些散射光在能量竞争中处于优势,最终形成的热像得到加强,而其它散射光形成的热像受到抑制。     

人眼像差校正仪视网膜动态稳像研究

针对人眼无意识的抖动导致图像位置在眼底成像设备上无规律变化而无法有效观察指定区域的问题,提出了一种视网膜图像实时动态稳像算法.该算法依据图像匹配理论,在图像探测的同时引入图像有效区域实时“计算-移位”.利用时间上相邻的视频序列图像近似对应于眼底同一位置的特点,通过“采集-运算”找到当前采集图像的中心区域.把当前图像的中心区域与第一帧采集图像的中心区域进行相关匹配,获取当前视网膜图像相对第一帧图像抖动的偏移方向和偏移量,然后把当前图像移位,循环执行此过程,并剔除无法匹配的图像,使得屏幕上的图像始终是在同一个位置的静态图像.实验证明：本文提出的算法解决了自适应眼底成像设备在对视网膜细胞观测时因为人眼自然抖动而造成的图像不稳定问题;解决了人眼在可见光波段的激光照明下受到较强刺激而无法长时观测的问题,实现了细胞和微血管同平台同算法观测;是采用拼接技术实现大视场图像的前提.     

激光告警中的信号探测研究

分析激光告警中的噪声电平，研究信噪比与探测概率，最后研究距离方程与动态范围。     

热等离子体中的相对论线跃迁概率研究

本文的目的是给出一种计算线跃迁概率的方法并同时研究线跃迁概率对热等离子体的温度、密度的敏感性。 对于有界原子,利用含温Thomas-Fermi统计势求解了径向Dirac波动方程,给出了计算电偶极线跃迁的严格理论公式和金元素在不同温度、密度下若干谱线的计算结果。     

亚像元动态成像技术中系统的调制传递函数

亚像元动态成像技术是国际上目前实现遥感器小型化非常有效的新方法，因而研究亚像元动态成像系统的调制传递函数（MTF）显得非常必要和重要。本文分析亚像元动态成像系统的MTF模型，并给出亚像元动态成像系统MTF的数学表达式。     

基于像清晰化函数最优化的高速机载相机动态像质补偿技术

为满足高速飞行器对目标快速识别和打击的需求,针对大观测场高速机载光电探测系统像质退化严重、像质补偿元件机构复杂、像差校正实时性较差的问题,提出采用可变形反射镜作为动态像质补偿器对传统高速动态成像光学系统像质进行补偿和改进.利用基于像清晰化函数最优化的自适应光学动态像质补偿技术的优化算法对系统动态像差进行闭环实时校正,通过仿真对所提出的方法进行可行性分析和验证.仿真结果表明:与校正前相比,该校正方法使光学系统在60°大角度观测场内泽尼克动态像差变化量的峰谷值最大下降17.5%,点列图弥散斑均方根半径降低至10.61%,校正后的系统残余像差小,在整个观测场内,像质均接近光学衍射极限.     

Evaluation of infrared collimators for testing thermal imaging systems

Infrared reflective collimators are important components of expensive sophisticated test systems used for testing thermal imagers. Too low quality collimators can become a source of significant measurement errors and collimators of too high quality can unnecessarily increase cost of a test system. In such a situation it is important for test system users to know proper requirements on the collimator and to be able to verify its performance. A method for evaluation of infrared reflective collimators used in test systems for testing thermal imagers is presented in this paper. The method requires only easily available optical equipment and can be used not only by collimator manufactures but also by users of test equipment to verify performance of the collimators used for testing thermal imagers.     

Variable detection probability in two-photon interference

We report here the results obtained by applying a local and realistic theory to photon intereference phenomena [1], recently observed in a set of experiments performed by Mandel and co-workers [4,6]. In these papers Mandel discarded the possibility of a rational explanation of his results, in the sense that the high visibility obtained was according to him far above the maximum allowed by a classical theory. We shall see how a small set of hypotheses, highly plausible for a realistically minded physicist, drives us to a large visibility in agreement with these experiments.     

Analysis of some large-scale nonlinear stochastic dynamic systems with subspace-EPC method

The probabilistic solutions to some nonlinear stochastic dynamic (NSD) systems with various polynomial types of nonlinearities in displacements are analyzed with the subspace-exponential polynomial closure (subspace-EPC) method. The space of the state variables of the large-scale nonlinear stochastic dynamic system excited by Gaussian white noises is separated into two subspaces. Both sides of the Fokker-Planck-Kolmogorov (FPK) equation corresponding to the NSD system are then integrated over one of the sub...     

Block-wise motion detection using compressive imaging system

A block-wise motion detection strategy based on compressive imaging, also referred to as feature-specific imaging (FSI), is described in this work. A mixture of Gaussian distributions is used to model the background in a scene. Motion is detected in individual object blocks using feature measurements. Gabor, Hadamard binary and random binary features are studied. Performance of motion detection methods using pixel-wise measurements is analyzed and serves as a baseline for comparison with motion detection techniques based on compressive imaging. ROC (Receiver Operation Characteristic) curves and AUC (Area Under Curve) metrics are used to quantify the algorithm performance. Because a FSI system yields a larger measurement SNR(Signal-to-Noise Ratio) than a traditional system, motion detection methods based on the FSI system have better performance. We show that motion detection algorithms using Hadamard and random binary features in a FSI system yields AUC values of 0.978 and 0.969 respectively. The pixel-based methods are only able to achieve a lower AUC value of 0.627.     

The effect of laser fluctuation statistics upon detection probability

The effects of laser beam irradiance fluctuations, such as speckle and scintillation, upon optical beam detection probability are examined in an entirely statistical context. The optical detector is assumed to possess a non-linear integrated log-normal response function, as is normally ascribed to the eye. Various statistical distribution functions purported to model these fluctuations accurately are examined from both numerical and analytical standpoints. The numerical results indicate that different models for fluctuation statistics predict detector threshold probabilities which differ from each other by more than 10%. Such variations may be significant in calculations relating to eye safety.     

动态法测定良导体热导率的实验研究

对“用动态法测定良导体热导率”实验的数据处理方法进行了探索，提出两种改进方法并在实际应用中得到了较好的效果，对实验涉及到的准一维热传导方程及其波动解作了理论分析（引入了散热修正）和解释。     

成像型激光探测系统动态范围扩展技术研究

 针对成像型激光探测系统动态范围不足的问题,以现有广角远心鱼眼透镜和CMOS摄像器件为硬件基础,提出通过图像处理的方法扩展系统动态范围。系统采用帧相减技术滤除背景干扰和噪声,进而进行激光光斑的识别和定位。在此基础上,针对接收激光能量的不同,提出采用不同方法扩展动态范围。当激光能量较低时,激光信号可能淹没在噪声中无法准确判读和精确定位,通过滤波技术排除噪声,提高图像信噪比,从而提高系统探测灵敏度,即扩展探测下限。对于探测上限,即当强激光入射时,由于鱼眼光学系统内会产生反射干扰光,有可能在成像面形成不规则的干扰光斑,通过光斑匹配模式识别的方法排除杂光干扰,提高识别上限。实验结果表明,该方法使系统动态范围从为70 dB提高到89 dB,提高近30%,有效扩大了探测系统的作用范围。     

Research on temperature distribution of combustion flames based on high dynamic range imaging

The imaging-based three-color method is widely used in the field of non-contact temperature measurement of combustion flames. In this paper, by analyzing the imaging process of a combustion flame in detail, we re-derivate the three-color method by adopting a theory of high dynamic range imaging. Instead of using white balanced, gamma calibrated or other algorithms applied 8-bit pixel values, we use irradiance values on the image plane; these values are obtained by combining two differently exposed raw images into one high dynamic range irradiance map with the help of the imaging system's response function. An instrumentation system is presented and a series of experiments have been carried out, the results of which are satisfactory.     

红外热成像法研究电路板热分布特性

介绍了一种红外热成像处理技术,以及利用这种红外热成像处理系统研究通电电路板的热平衡分布特性。     

T型架光电经纬仪动态精度检测方法的研究与应用

根据动态精度靶标的机械结构和由a,b,θ角计算出来的光电经纬仪回转中心的空间位置,结合T型架光电经纬仪的机构特点,采用偏心的方法对其进行动态精度的检测。通过对某型号光电经纬仪的实际检测,验证了该方法的正确性。