Calibration Access and Data Handbook

Generation from In-Orbit Data

Darkframes are calculated from flatfield data with the filter wheel in blocked position and the LEDs switched off. Darkframe images of several exposures are co-added to achieve good statistics. The co-added image is divided through the sum of the exposure durations to obtain the dark count rate. The average statistical uncertainty of each pixel content and the average dark count rate together with its uncertainty are stored as keywords.