Dither correction for infrared detector arrays

Abstract

Methods of calculating gain correction values and offset correction values for detector elements of an infrared detector array, under “abnormal” conditions, such as when the scene is in motion or when-there is dither bias. The methods can be adapted for one-dimensional scanning arrays or for two-dimensional staring arrays. (FIGS.,and,). The array is mechanically dithered so that two or more neighboring detector elements of the array look at the same location of a scene. (FIG.,Step,FIG.,Step,). Then, the fields of pixel data are processed to calculate a gain correction value and an offset correction value for each detector element. (FIG.,Steps,and,FIG.,Steps,and,). For each detector element, its gain error and its offset error are calculated from local averages, with the local average for a particular detector element including a term for that detector element as well as terms for its neighboring detector elements. The basic method may be modified for scene motion, dither bias, or other abnormal conditions.