Linearity Set from 20120918

A set of linearity data were obtained with the dome flat system and the r-band filter on this date (see Run Manager Report 2012-09-19.ppt). These data include the following files and exposure times:

134765 0.1 134758 3.0
134752 0.2 134759 4.0*
134753 0.4 134760 5.0
134754 0.6 134761 6.0
134755 0.8 134762 7.0
134756 1.0 134763 8.0
134757 2.0 134764 10.0

The files with exposure times of 3s and longer show evidence of saturation. The 3s exposure is close to saturation, but does exhibit some of the 'curl down' characteristic of saturation. The 5s and longer exposures are strongly saturated.

I analyzed the data from 0.2s to 2.0s to determine if the median count rate on each amplifier was consistent with a linear increase in count rate with time. Specifically, I subtracted consecutive pairs of images (0.4s - 0.2s, 0.6s - 0.4s, 0.8s - 0.6s, 1.0-0.8s, and 2.0 - 1.0s), divided by the exposure time difference, and then calculated the median of each amplifier on each chip. The rms of all of these rates were consistent with linear to better than 1%, with the exception of both amplifiers on FS4 and both on FN2.

Paul Martini
27 September 2012