Signal to Noise Ratio and its Processing in Array Detector

In this paper, factors which affect the signal to noise ratio (S/N) for the photographic film, photoelectric tube and CCD are discussed. In addition, the related formulae of the total S/N and S/N ratios of individual pixels for the photoelectric array are derived. Based upon those, the leading significance of the S/N ratio relations are discussed emphatically in astronomical observations and data processing.