Raytheon Company

Ching-ju Jennifer Young

Robert C Gibbons

A-Lan V Reynolds

Kent McCormack

Larry A Turner

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 &ldquo;one-step&rdquo; method uses the sum of &ldquo;shifted image differences&rdquo; from two fields. A &ldquo;scene term&rdquo; may be added to each offset correction value to compensate for dither bias.

Methods of non-uniformity compensation for infrared detector arrays

Methods of calculating gain correction values and offset correction values for detector elements of an infrared detector array, under &ldquo;abnormal&rdquo; 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.

Dither correction for infrared detector arrays

Methods of calculating gain correction values and offset correction values for detector elements of an infrared detector array. The methods can be adapted for one-dimensional scanning arrays or for two-dimensional staring arrays. (FIGS. 3 and 6). 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. 3, Step 302; FIG. 6, Step 601). Then, the fields of pixel data are processed to calculate a gain correction value and an offset correction value for each detector element. (FIG. 3, Steps 305, 309, and 311; FIG. 6, Steps 603, 607, and 611). 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.

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Dallas, TX, United States of America

Ching-ju Jennifer Young