抚仙湖太阳观测和研究基地知识库

讨论了电子倍增电荷耦合器件(Electron-Multiplying Charge-Coupled Device,EMCCD)附加噪声的产生机理及特性,通过模拟详细分析了EMCCD附加噪声对天文图像高分辨统计重建技术——斑点干涉术传递函数信噪比的影响,并和实验进行了对比,结果表明,在星体暗弱时,由附加噪声引入的偏差将使斑点干涉术重建的信噪比下降,严重影响重建的结果,必须加以改正。由实测数据重建结果可以看出,噪声偏差改正模型基本解决了EMCCD附加噪声对斑点干涉术在重建目标自相关或模时的影响。

Based on the discussion of generating mechanisms and characteristics of additional noise of an Electron-Multiplying CCD,we use simulations to analyze the effect of the noises on the Astronomical High-Resolution Statistical Reconstruction Method ( Speckle Interferometry ). We compare our analysis to experimental results. We show that the bias introduced by the additional noise reduces the Signal-to-Noise Ratio of Speckle Interferometry when the object is faint. The bias seriously affects the results of reconstruction and must be corrected. It can be clearly seen from the result of reconstruction of real data that our noise-bias correction can effectively remove the effects an of EMCCD additional noise on the reconstruction of the autocorrelation or power spectrum of an object image in the Speckle Interferometry.