An introduction to some imperfections of CCD sensors

TL;DR

This paper reviews imperfections in CCD sensors, including linear and non-linear effects like flux-dependent and static distortions, emphasizing their importance for accurate data reduction in large astronomical surveys.

Contribution

It provides a comprehensive summary of current findings on CCD sensor imperfections and discusses methods for their characterization and mitigation.

Findings

Evidence of flux-dependent distortions in CCDs

Identification of static image distortions

Discussion of mitigation techniques

Abstract

CCD sensors do not deliver a perfect image of the light they receive. Beyond the well known linear image smearing due to diffusion of charges during their drift towards the pixel wells, non-linear effects are at play in these sensors. We now have ample evidence for both a flux- dependent and static image distortions, especially but not only, on deep-depleted CCDs. For large surveys relying on CCD sensors, these effects should now be taken into account when reducing data. We present here a summary of current results on sensor characterization and mitigation methods.