Читать книгу The Doppler Method for the Detection of Exoplanets - Professor Artie Hatzes - Страница 30

For photon statistics, σ2=Np=GNp. A series of exposures of a white-light source at increasing intensity levels (exposure times) is made, the bias level from each frame is subtracted, and the standard deviation on a region of the detector is calculated. The slope of the σ2 versus the intensity (ADU) level (after subtracting the bias level) yields the gain (Figure 2.16).

Figure 2.16. The standard deviation of ADU values from a CCD as a function of the intensity (ADU) level. The slope indicates a CCD gain of 0.56 electrons per ADU.