光子传输曲线（PTC，方差与信号电平）是表征CCD性能的常用且有效的工具。在光子散粒噪声占主导地位的范围内，它在理论上是线性的，并且它的斜率被用来导出CCD的增益。然而，最近对不同CCD的研究表明，在高信号水平下，方差逐渐下降，而信号与曝光时间的线性关系仍然很好，不受影响。另一方面，亮星表现出较胖的点扩散函数（PSF）。非线性PTC和亮胖效应都被认为是像素之间电荷扩散的结果，这种相互作用随着信号电平的增加而增加。在这项工作中，我们研究了非线性PTC的基础上的图像与STA 1600 FT CCD相机，其PTC开始成为非线性约1/3满阱。为了解释这一现象，我们提出了一个模型来表征电荷共享PSF。这种信号依赖的PSF可以从平场框架中导出，并允许我们量化测光和测量的恒星形状的影响。这种效应对于需要精确光度和形状参数的项目至关重要。
英文摘要：
The photon transfer curve (PTC, variance vs. signal level) is a commonly used and effective tool in characterizing CCD performance. It is theoretically linear in the range where photon shot noise dominates, and its slope is utilized to derive the gain of the CCD. However, recent researches on different CCDs have revealed that the variance progressively drops at high signal levels, while the linearity shown by signal versus exposure time is still excellent and unaffected. On the other hand, bright stars are found to exhibit fatter point spread function (PSF). Both nonlinear PTC and the brighter-fatter effect are regarded as the result of spreading of charges between pixels, an interaction progress increasing with signal level. In this work we investigate the nonlinear PTC based on the images with a STA1600FT CCD camera, whose PTC starts to become nonlinear at about 1/3 full well. To explain the phenomenon, we present a model to characterize the charge-sharing PSF. This signal-dependent PSF can be derived from flat-field frames, and allow us to quantify the effects on photometry and measured shape of stars. This effect is essentially critical for projects requiring accurate photometry and shape parameters.
The effects of charge transfer inefficiency (CTI) on galaxy shape measurements
我们研究了电荷转移效率（CTI）的影响，在CCD读出星系形状测量所需的弱引力透镜的研究。我们模拟了CCD读出与CTI，如带电粒子辐射损伤所造成的。我们验证我们的模拟实验室辐照CCD的数据。只有电荷陷阱的时间常数相同的顺序，在读出过程中的行传输之间的时间影响星系的形状测量。我们描述了CTI对不同星系种群的影响。我们的基线我们的研究围绕p沟道CCD已被证明具有电荷转移效率高达一个数量级优于几个型号的n沟道CCD设计用于空间应用。我们预测，对于距离读出寄存器最远的星系，星系形状测量的偏差Delta（e）将以每年2.65 +/- 0.02 x 10^（-4）的速度在L2处增加，以获得整个太阳周期的平均累积辐射照射。如果不进行校正，这将在大约4年内消耗暗能量任务的整个形状测量误差预算。其他地方展示的软件缓解技术可以将其降低约10倍，使其效果远低于任务要求。具有比我们研究的更高CTI的CCD可能无法满足未来暗能量任务的要求。我们将讨论如何设计硬件，以进一步减少CTI的影响。
First Cosmology Results Using Type Ia Supernovae from the Dark Energy Survey: Effects of Chromatic Corrections to Supernova Photometry on Measurements of Cosmological Parameters
