Methods of non-uniformity compensation for infrared detector arrays

Abstract

Improved methods of calculating offset correction values for detector elements of an infrared detector array. The methods can be used for one-dimensional scanning arrays, and performed twice for two-dimensional staring arrays. (FIGS.,and,). The array is dithered so that two or more neighboring detector elements of the array look at the same location of a scene. (FIG.,, Step,). Then, two fields of pixel data are processed to calculate an offset correction value for each detector element. (FIG.,, Steps,, and,). For each detector element, its offset error is 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 a neighboring detector element. A “one-step” method uses the sum of “shifted image differences” from two fields. A “scene term” may be added to each offset correction value to compensate for dither bias.