Read Noise

Close examination of Figure 6 shows that even for a bias subtracted mean of zero, there is still a small amount of variance within our data. We would expect the variance to go to zero when we have a pixel readout of zero if we had perfect measurements of every pixel value. However, we see that this is not the case. Therefore, this variance must be due to the read noise as discussed in Section 3.5. So, we can see that the read noise for our CCD is about 5 $\frac{DN}{pixel}$ or 7.5 $\frac{\char93 \; e^{-}}{pixel}$.