科学级CCD三维噪声模型及其评估

为了评估科学CCD噪声带给激光近场分布测量的影响,采用三维噪声模型,分析了科学级CCD的噪声,并将CCD的噪声分解为空间噪声和时间噪声。空间噪声用来评估CCD像元之间响应不一致性对测量的影响,时间噪声用来评估多次测量不一致性对测量的影响。通过设计测量系统对CCD三维噪声进行测量,并分析时空噪声的统计分布规律,发现两者均是依赖于信号、近似服从正态分布,建立了依赖于信号的时空噪声的数学模型,并实验验证了该模型是有效的。

3-D noise model and evaluation of scientific grade CCD

To evaluate the influences resulted by CCD noise in laser near field distribution measurement,3-D noise model was used to analyze the characters of CCD noise which was classified into spatial noise and temporal noise.Spatial noise was used to evaluate influences resulted by no-uniformity between different pixels,and temporal noise was used to evaluate influences resulted by multiple measurements.To measure system noise,CCD 3-D noise measurement system was designed,it was composed of semiconductor laser,integrating sphere,attenuating plate,scientific grade CCD,optical power meter and computer.Integrating sphere was used to unify the input laser and CCD was connected to one of its output ports.Optical power meter was used to record optical power accepted by CCD which could be changed by adjusting attenuating plate.CCD output data to export PC were used to analyze CCD noise.By testing for one type of scientific grade CCD,it was concluded that spatial noise and temporal noise were signal-dependent terms and followed normal distribution.The relationship model between standard deviation of noise and signal was studied,and one way of identifying the parameters of model was proposed.The experiments verified that this model was effective.