Characterisation of the signal and noise transfer of CCD cameras for electron detection
Characterisation of the signal and noise transfer of CCD cameras for electron detection
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用于电子检测的 CCD 相机的信号和噪声传输特性
DOI：
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发表时间：
2000
期刊：
影响因子：
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通讯作者：
A. Kirkland
中科院分区：
文献类型：
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作者：
R. Meyer;A. Kirkland
研究了用于电子探测的CCD相机性能的表征方法，特别强调了信号和噪声传输之间的差异。与描述图像中对比度的空间频率相关衰减的调制传递函数MTF类似，我们引入了噪声传递函数NTF，该函数描述了任何电子图像中不可避免存在的泊松噪声的传递。给出了图像转换器信号和噪声传输的一般模型。这允许通过蒙特卡罗模拟闪烁体中电子和光子的轨迹以及相机的光学耦合来计算MTF和NTF。此外，还提出了精确测量调制传递函数和噪声传递函数的实验方法。空间频率相关的检测量子效率（DQE）是相机的一个重要的性能指标，迄今尚未进行实验测量，可以从测量的MTF和NTF中得到。实验结果与仿真结果吻合较好，表明在高空间频率下，NTF比MTF高4倍。这意味着经常用于测量MTF，但实际上测量NTF的噪声方法给出了过于乐观的结果。此外，空间频率相关的DQE比先前假设的要低。Microsc。科技进步，49:269 - 280,2000。©2000 Wiley‐Liss, Inc。
Methods to characterise the performance of CCD cameras for electron detection are investigated with particular emphasis on the difference between the transfer of signal and noise. Similar to the Modulation Transfer Function MTF, which describes the spatial frequency dependent attenuation of contrast in the image, we introduce a Noise Transfer Function NTF that describes the transfer of the Poisson noise that is inevitably present in any electron image. A general model for signal and noise transfer by an image converter is provided. This allows the calculation of MTF and NTF from Monte‐Carlo simulations of the trajectories of electrons and photons in the scintillator and the optical coupling of the camera. Furthermore, accurate methods to measure the modulation and noise transfer functions experimentally are presented. The spatial‐frequency dependent Detection Quantum Efficiency DQE, an important figure of merit of the camera which has so far not been measured experimentally, can be obtained from the measured MTF and NTF. The experimental results are in good agreement with the simulations and show that the NTF at high spatial frequencies is in some cases by a factor of four higher than the MTF. This implies that the noise method, which is frequently used to measure the MTF, but in fact measures the NTF, gives over‐optimistic results. Furthermore, the spatial frequency dependent DQE is lower than previously assumed. Microsc. Res. Tech. 49:269–280, 2000. © 2000 Wiley‐Liss, Inc.
透射电子显微镜用薄箔闪烁屏的性能。
影响因子：
2.2
作者：
Fan,GY;Dunkelberger,DG;Ellisman,MH
通讯作者：
Ellisman,MH