室内多波段光轴一致性测试系统的设计

介绍用于室内检测多波段光电设备光轴一致性的测试系统。该系统采用准直平行光管为测试系统提供无穷远目标。为满足全波段测试，光束无中心遮拦，系统选用离轴抛物面全反射光学系统。采用多光谱分光镜为激光光斑提供瞄准基准，带温控热十字丝的高斯目镜为红外和可见光波段提供瞄准基准，实现了光电设备之间可见与红外、可见与激光、激光与红外光轴的一致性测试。系统具有测试精度高、测试结果可靠等特点。根据初步估算，可见与红外、可见与激光、红外与激光之间的光轴一致性测试精度分别达到了4.01″， 1.08″和 4.05″的水平。该系统有效解决了多波段光测设备光轴间的一致性测试问题。     

Outage performance analysis for relay-assisted UWOC systems over GGD weak turbulence with nonzero boresight pointing errors

In this paper, we mainly investigate the outage performance of serial and parallel relay-assisted underwater wireless optical communication (UWOC) systems based on a newly proposed aggregated underwater fading model. In order to overcome the deficiency of the traditional underwater weak turbulence models, that is, they could not accurately fit the measured data in the laboratory, the generalized gamma distribution (GGD) which has been verified by a series of experiments is chosen for the first time to characterize the weak oceanic turbulence. Then, we establish a new receiving signal model which has integrated the implicit path loss plus multipath propagation effect shown by fading free impulse response (FFIR), GGD weak oceanic turbulence, and nonzero boresight pointing errors. Next, we deduce the closed-form expression of the probability density function (PDF) of the hybrid fading considering GGD weak turbulence and nonzero boresight errors based on the new receiving signal model above through double-exponential Taylor expansion and higher transcendental Whittaker function. Finally, the analytical expressions of the outage probabilities for point-to-point (P2P) link, serial and parallel relay-assisted UWOC systems are further derived respectively under the proposed aggregated channel. Numerical simulations are also provided to validate the accuracy of the theoretical formulae derived above, and to show the effects of the key system parameters on the outage performance of relaying UWOC systems.     

回波瞄准系统中基于爬山法的光束闭环瞄准实验

瞄准偏差和光束抖动,会导致光束到达靶面能量的损失,是光束瞄准系统中两个最主要的误差。分析了以高斯光束和高斯抖动为基础的光束在照明目标时产生的光回波信号的特性;在此基础上,搭建了实验室平台,实现了基于二维爬山法的光束闭环瞄准,讨论了光束抖动对光束瞄准实时性的影响,分析了不同抖动强度下光束瞄准的精度。实验结果表明：爬山算法无需已知目标和光束分布的任何信息,即可实现光束回波闭环瞄准,且性能优良;但随着光束抖动的增加,其瞄准所需回波信号样本增大,瞄准精度降低。     

基于机器视觉的轴偏角归一化检测系统

在复杂的测控、发射、跟踪等系统的制造和使用中，分系统或部件间的安装位置偏差会影响控制、跟踪、发射的精度和系统其他指标测量结果的准确性，因而需要进行测量和校正。提出了基于视觉图像定位光斑中心的轴偏角测量方法，并基于LABVIEW虚拟仪器平台构建了机器视觉测角系统。以某大型武器系统为测试平台，对不同属性的轴(如发射轴、瞄准轴、激光指示器轴、制导中的测量基线等)进行归一化测量和校准，得到了满意的效果。     

大气环境下基于目标照明回光的视轴误差校正实验研究

理论分析了激光瞄准系统中视轴误差与目标照明回光的关系. 介绍了同时具备激光束发射与瞄准偏差校正功能的自适应光学器件––自适应光纤准直器的原理. 搭建了光束经200 m水平大气传输的激光瞄准实验平台. 基于二维目标和三维目标的照明回光, 利用随机并行梯度下降算法分别实现了不同初始视轴误差下的瞄准闭环校正. 实验结果表明, 闭环后二维目标和三维目标的视轴校正残差评价参数分别小于6%和10.8%, 校正精度均在理论范围内. 最后, 分析了算法参数对动目标瞄准的影响.     

Research on detection system of optical sights triaxial parallelism

A method for testing triaxial parallelism of optical sights, the triaxial which involve optical sights targeting axis of white & infrared and laser launching axis, is put forward in this paper on the basis of analyzing conventional measuring technique. At first, measuring optical path is improved, and some equipments such as aspherical mirror, high precision CCD camera are employed to eliminate the subjective error; with the analysis of the optical path, the mathematical model of triaxial parallelism is built, and the error factors are analyzed and calculated. Finally the system is calibrated by autocollimation theodolite whose accuracy is 0.5″ and the experimental results show that measurement error is <3″. In a word, the method has great significant engineering value.     

视轴角控制误差对航天相机成像质量的影响分析

为了降低飞行器倾斜成像工作过程中视轴角误差对TDICCD空间相机成像质量的影响,提出满足相机成像质量的视轴角范围及控制误差的要求。根据空间相机成像机理,给出了焦面像移速度以及由视轴角误差引起的像移速度匹配误差计算公式,分析了视轴角对地面像元分辨力的影响。并以调制传递函数(MTF)为约束条件给出了不同积分级数下视轴角的范围。通过实际工程参数计算得出,当视轴角控制误差为0.8时,满足96级TDICCD成像质量要求的视轴角应不大于12.75;若要满足96级TDICCD倾斜成像时视轴角达到25,则视轴角控制误差应优于0.4。     

强激光与红外光学系统光轴平行性检测方法的探讨

介绍3种可测量强激光发射光轴与红外光轴平行性的方法及每种方法的优缺点，重点研究了利用热靶进行波段转换来测量激光与红外光学系统光轴平行性的方法。该方法是将激光聚焦在热靶上，使热靶产生热量并发出红外光，红外光再经过准直进入被测设备的红外光学系统，从而测量出激光光轴与红外光轴的平行性。热靶材料的选择与激光透过率的确定尤为重要，该方法中选用酚醛树脂作为热靶材料，激光的透过率仅为0.5%。通过与远距离目标靶测量法进行比对实验，发现2种方法得到的测量结果一致，从而验证了这种方法的可行性与正确性。