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91.
温度变化导致航天相机光学系统像面位移的研究 总被引:3,自引:0,他引:3
温度变化导致的像面位移会影响航天相机光学系统的成像质量。根据高斯光学理论,推导出了温度变化时的相机光学系统的像面位移公式,确定了温度敏感性最低的主、次反射镜的材料及与之相匹配的镜筒材料。最后计算和比较了在不同温度变化时的光学系统的传递函数。 相似文献
92.
Wang Xiaoyu Wang Pingjiang Chen Jihong 《International Journal of Infrared and Millimeter Waves》2007,28(1):99-111
Infrared camera has been widely used in electrical power systems for predictive and preventive thermal fault diagnosis. Without
historical IR images being considered, most thermograph analysis used at present are concerned with static image. The dynamic
history and tendency analysis which compares the newly taken image with historical images is particularly attractive. Conclusions
can be drawn from temperature variations rather than just from anomalous thermal pattern. However the spatial distortions
prevent such dynamic analysis from being practicable. So the need to register infrared images arises. This paper proposes
an automatic registration algorithm based on closed temperature contour matching for infrared image series of a target equipment
taken at different times. Centroid Distance Function is used in image registration for the first time. The algorithm can remove
spatial distortions, bring temperature variations into prominence and endow infrared camera with dynamic analysis ability.
Experiment shows that the algorithm is simple, effective and extensible. 相似文献
93.
本文介绍了用全息干涉法诊断爆炸丝等离子体的数据处理方法。在考虑等离子体区域为轴对称的情况下,给出了由折射率计算等离子体电子密度的计算公式。在爆炸丝能量为9.6J的情况下,拍摄到了延时3μs的爆炸丝等离子体干涉图。运用计算机图象处理技术对反拍后的干涉图进行了处理,获得了较为理想的干涉图。用微机控制的线阵CCD摄像机判读了干涉条纹漂移。给出了等离子体密度随径向分布的曲线,并得到相应的等离子体密度在中心处约为1016个/cm3。 相似文献
94.
圆扫描变像管人卫激光测距技术研究 总被引:1,自引:1,他引:0
在本文中,我们设计并研制了用于毫米级精度人卫激光测距的圆扫描时间分析系统。研制的圆扫描变像管理论时间分辨率可优于3ps,可用于双色测距;偏转灵敏度高达10cm/kV,偏转空间分辨率优于24lp/mm;利用双MCP内增强,增益~1×106,并有门控功能以进一步提高信噪比和动态范围。扫描控制电路能提供300MHz、10W的正弦信号,其频率、幅度、相位稳定度均可满足要求。调试过程中较好地解决了阻抗变换、空间干扰和相位正交等关键问题。在仅2W的RF功率驱动下,即可实现稳定的φ24mm的圆扫描,系统实测时间分辨率达4.8ps。在实验室实测测距精度达亚毫米级。动态实验及模拟测距表明,该时间分析系统可满足第四代人卫激光测距系统的需要。 相似文献
95.
Electrowetting-Based Variable-Focus Lens for Miniature Systems 总被引:1,自引:0,他引:1
B. H. W. Hendriks S. Kuiper M. A. J. VAN As C. A. Renders T. W. Tukker 《Optical Review》2005,12(3):255-259
The meniscus between two immiscible liquids of different refractive indices can be used as a lens. A change in curvature of this meniscus by electrostatic control of the solid/liquid interfacial tension leads to a change in focal distance. It is demonstrated that two liquids in a tube form a self-centred variable-focus lens. The optical properties of this lens were investigated experimentally. We designed and constructed a miniature camera module based on this variable lens suitable for mobile applications. Furthermore, the liquid lens was applied in a Blu-ray Disc optical recording system to enable dual layer disc reading/writing. 相似文献
96.
The generation and the subsequent evolution of dynamic failure events in homogeneous layered materials that occur within microseconds after impact were investigated experimentally. Tested configurations include three-layer and two-layer, bonded Homalite specimens featuring different bonding strengths. High-speed photography and dynamic photoelasticity were utilized to study the nature, sequence and interaction of failure modes. A series of complex failure modes was observed. In most cases, and at the early stages of the impact event, intra-layer failure (or bulk matrix failure) appeared in the form of cracks radiating from the impact point. These cracks were opening-dominated and their speeds were less than the crack branching speed of the Homalite. Subsequent crack branching in several forms was also observed. Mixed-mode inter-layer cracking (or interfacial debonding) was initiated when the intra-layer cracks approached the interface with a large incident angle. The dynamic interaction between inter-layer crack formation and intra-layer crack growth (or the so-called “Cook–Gordon Mechanism”) was visualized for the first time. Interfacial bonding played a significant role in impact damage spreading. Cracks arrested at weak bonds and the stress wave intensity was reduced dramatically by the use of a thin but ductile adhesive layer. 相似文献
97.
98.
首次使用双狭缝相机对“神光”装置南路倍频线聚焦激光打靶所形成的线状等离子体均匀性进行了监测。由于实验条件的限制,相机的测量位置不太理想。为此,我们进行了修正,本文即是在修正基础上给出实验结果。修正后的结果表明,“神光”装置南路倍频线聚焦激光打靶部分发次所形成的线状等离子体均匀性不够理想。 相似文献
99.
100.
转镜式高速相机扫描速度及其不均匀性测量 总被引:1,自引:0,他引:1
介绍了高速相机扫描速度不均匀性产生的原因、扫描速度测量的方法,简要地介绍了测量系统的工作原理,测时精度达到3ns,测速精度达到 3,最后给出了测量 GSJ型和SJZ-15型相机的结果。 相似文献