ALFOSC CCD14 linearity with ccd3-controller
The x-axis shows the signal level in ADUs and
y-axis the "linearity residual" (LR).
The horizontal dashed lines show the +-1% level of non-linearity.
The data was taken April 2016 using the beta-light source and Novemeber
2016 using the beta-light source + filters.
This indicates that the system is linear (better than +-1%) up to
~600 kADUs (full well= 135ke-/pixel, 700 kADU/pixel).
The integration time are from 0.4 to 600 seconds.
The "linearity residual" (LR) equation:
where LR is the linearity residual at a specific signal level (%).
The variables S(DN) and tE are the measured signal and exposure time
(seconds). The tEM is the exposure time required to produce
a signal (sec), SM at mid-scale in the plot (DN) [Taken from
"Scientific Charge-Coupled Devices" pp 117 by James R. Janesick,
SPIE press 2001].
measurements based on the cryostat LEDs (Oct/Nov 2018), for various CCD setups.