Experimental assessment of relative temporal fluctuation of CCD pixels

Instituto de Fisica Aplicada, Consejo Superior de Investigaciones Cientificas (CSIC), c/ Serrano 144, 28006 Madrid, Spain

Corresponding author: aferrero@ifa.cetef.csic.es

Received: 17 June 2005
Revised: 21 November 2005
Accepted: 12 January 2006
Published online: 4 April 2006

Abstract

A simple and straightforward method to assess the relative temporal fluctuation of the individual pixels in a CCD array with respect to the fluctuation of the spatial average is proposed. This procedure is based on the comparison of the low-frequency temporal noise of the individual pixels and the value of this magnitude averaged over the entire CCD. Moreover, this method is able to detect the presence of bad pixels within the array (drifting and flicking). The importance of this study resides in the need to know whether or not the behavior of the individual pixels can be approximated by that of the spatial average and to assess the stability of Nonuniformity Correction algorithms (NUC). Once the mathematical formulation was developed, it was applied to the analysis of a specific CCD array, the Sony ICX414AL. The results show three different trends in the behavior of its pixels.