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为提高某中波红外探测器的图像质量,设计了基于FPGA的红外图像实时处理系统,系统能够完成实时的非均匀性校正与盲元补偿处理。介绍了目前常用的非均匀性校正、盲元识别和补偿算法,并结合实际工程需求采用多点法进行非均匀性校正以及8点平均法进行盲元补偿。在仿真实验成功的基础上,基于FPGA平台构建了硬件平台。系统可以实现系数自定义更新,可以手动或自动完成非均匀性较正系数计算,以及实现盲元列表的自动更新操作。利用某国产中波红外探测器对处理系统进行了测试试验,实验结果表明:校正后图像非均匀性0.3%,盲元率0.001%。系统工作稳定、可靠,图像处理满足实时性和精度要求。 相似文献
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本文理论计算了多峰离子源永磁体, 采用二体碰撞模型处理电子之间的库仑碰撞, 运用空碰撞方法处理电子与氢元素相关粒子碰撞, 开发了全三维粒子模拟-蒙特卡罗模拟算法, 并采用此软件对热门多峰离子源JET-60U的两种优化设计模型进行数值模拟研究, 探索了两种离子源空间分布特性和体积负氢离子产率相关问题, 提出了负氢离子源设计的基本思想: 适当调整离子源多峰磁场分布情况可以输出均匀离子束; 适当调整引出磁场大小和离子源结构, 可以达到离子束空间均匀性和高产率兼顾的效果. 相似文献
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An experimental study of natural convection in a parallelepipedal enclosure induced by a single vertical wall is described. The upper half of this wall was warm and the lower half cold. The other enclosure walls were insulated. The temperature and flow measurements were performed in the high Rayleigh number regime (1010<Ra<5×1010) by using water as the working fluid. The Rayleigh number was based on the enclosure height and the temperature difference between the warm and the cold part of the driving wall. The flow field featured two flat cells, one filled with warm fluid along the top horizontal wall, and the other filled with cold fluid along the bottom horizontal wall. Each of these cells was surrounded by an additional cell as tall as half the enclosure height. The above flow structure prohibited extensive thermal contact between warm and cold fluid, thus limiting the role of convection on the heat transfer process in the cavity. The findings of this study differ significantly from the findings of previous studies based on the ‘classical’ enclosure model possessing two isothermal vertical walls, the one warm and the other cold, and support the view that the use of ‘more realistic‘ temperature boundary conditions in enclosure natural convection needs careful examination. 相似文献
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This paper introduces a new scene-based technique to correct the fixed-pattern noise (FPN) in array sensors. This method registers a pair of image frames exhibiting small relative scene translation and then the noise pattern can be reconstructed using the constrained least-squares estimation. The key advantage of this technique is that the accurate estimates of the bias nonuniformity can be obtained with only two images, without imposing any assumptions on the structure of the FPN. Besides, the method works on almost static scene, and therefore does not require larger scale global motion and statistical assumptions on the scene irradiance. We test our method on synthetically generated FPN as well as with real infrared data, and experimental results demonstrate the significant reduction in FPN, validating the effectiveness of our approach. Finally, we validate the feasibility and validity of using the proposed method as a first step fostering the success of more sophisticated registration-based time-evolving correction algorithms. 相似文献
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李朋杰 李智焕 陈志强 吴鸿毅 田正阳 蒋伟 李晶 冯骏 臧宏亮 刘强 牛晨阳 杨彪 陶龙春 张允 孙晓慧 王翔 刘洋 李奇特 楼建玲 李湘庆 华辉 江栋兴 叶沿林 《原子核物理评论》2017,34(2):177-183
介绍了利用硅探测器的脉冲形状甄别进行粒子鉴别的原理。详细叙述了基于数字化方法的脉冲形状甄别的实现。采样频率和位数是数字化方法的两个重要参数。对于硅探测器信号,采用100 MS/s,12 bit的Digitizer可以满足脉冲形状甄别法对时间分辨的要求。同时对该方法粒子鉴别的特征和能量阈值做了简要的分析和对比。粒子背面入射硅探测器的所得的阈值低于正面入射的情况。例如对于氖周围的同位素,背面入射情况的阈值约为100 MeV,为正面入射情况下鉴别阈值的二分之一,相当与ΔE-E方法中ΔE探测器厚度约为60 μm情况下的阈值。最后定性讨论了硅探测器的电阻率不均匀性和沟道效应对粒子鉴别性能的影响。In this paper Pulse Shape Discrimination(PSD) for silicon detector has been briefly introduced. The emerging digital method successfully applied to detector signal processing makes digital PSD method one of the most promising particle identification methods. Sampling frequency and the number of bits are two key parameters of digital method. For silicon detector signal, adopting 100 Ms/s, 12 bit Digitizer can satisfy the time resolution requirement of PSD method. The identification characteristic and energy threshold of this method have been discussed and compared with both front injection and rear injection cases. Energy threshold with rear injection usually is much lower than that with front injection. For example, around for Neon isotope energy threshold with rear injection is about 100 MeV which is only half of the threshold with front injection, also equivalent to thickness of about 60 μm silicon detector threshold in ΔE-E method. At the end the impact of silicon detector's resistivity nonuniformity and channel effect on the identification capacity of PSD method has been discussed in detail. 相似文献
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为使制冷型中波红外热像仪在不同环境温度下经过非均匀性校正后保持较高的测温精度,研究了考虑非均匀性校正温度效应的中波红外热像仪标定模型。利用不同温度的面源黑体对热像仪进行非均匀性校正,然后对黑体目标进行测温实验,获得了不同校正温度下热像灰度与黑体辐射亮度之间的变化关系,建立了目标的测温数学计算模型,最后对测温结果进行误差分析。结果表明:在不同校正温度下,热像灰度相对非均匀校正辐亮度的漂移可做线性化处理,且与目标温度变化无关。在非均匀性较低的测温范围内热像仪的测温误差小于±0.22 ℃,极大减小了制冷型中波红外热像仪在不同校正温度下非均匀性校正后的测温误差。 相似文献