The authors would like to acknowledge financial support by Portland State University's "Faculty Development Grant" and the MJ Murdock charitable trust's "Partners in Science" program
Proc. SPIE 7875, Sensors, Cameras, and Systems for Industrial, Scientific, and Consumer Applications XII
Image processing -- Digital techniques, Charge coupled devices, CCD cameras, Electric currents -- Measurement
It is generally assumed that charge-coupled device (CCD) imagers produce a linear response of dark current versus exposure time except near saturation. We found a large number of pixels with nonlinear dark current response to exposure time to be present in two scientific CCD imagers. These pixels are found to exhibit distinguishable behavior with other analogous pixels and therefore can be characterized in groupings. Data from two Kodak CCD sensors are presented for exposure times from a few seconds up to two hours. Linear behavior is traditionally taken for granted when carrying out dark current correction and as a result, pixels with nonlinear behavior will be corrected inaccurately.
Justin C. Dunlap; Erik Bodegom; Ralf Widenhorn; Nonlinear time dependence of dark current in charge-coupled devices. Proc. SPIE 7875, Sensors, Cameras, and Systems for Industrial, Scientific, and Consumer Applications XII, 78750H (2011).