Noise in CTA Darks of 12/21/00

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Since not everyone can grasp easily what Tom's fourier analysis means, I have included the following images.

These are consecutive fowler-sampled frames from Channel 1 taken during the 20001221_lff_b flt_zero_pnt test. Although the typical DN level of the pattern noise is typically 1-6 DN, it is variable and well-correlated spatially. It seems to vary on minutes timescales. In general at least half the frames taken on this day look like this, often more. The frequency of contamination varies from day to day, which I believe strongly suggests variable levels of external activity (like the crane moving) at the Ball test facility.

12 second frames:

20001221_zero_pt_10.0.jpg	20001221_zero_pt_10.4.jpg	20001221_zero_pt_10.8.jpg	20001221_zero_pt_10.12.jpg	20001221_zero_pt_10.16.jpg

200 second frames:

20001221_zero_pt_13.3.jpg	20001221_zero_pt_13.10.jpg	20001221_zero_pt_13.17.jpg