Non-uniformity correction in a long wave infrared focal plane array as a calibration temperature function

Abstract

Despite the manufactory process, all detector or pixel in a Focal Plane Array (FPA) has a different responsivity and off-set when evaluated. These variations result in a specific kind of noise, called Fixed Pattern Noise (FPN) or spatial noise. During the image processing, pixels that have a large deviation in responsivity or in their noise are considered bad pixels, and have their influence removed during the exhibition of a scene. Knowing the response of all pixels to a uniform irradiation is the first test procedure in an FPA characterization. However, during the Non-uniformity correction and bad pixel replacement it is necessary to choose two reference temperatures, calibration points, and these temperatures affect important parameters such as Uniformity, Noise Equivalent Temperature Difference (NETD) and Signal Transfer Function (SiTF). Following standard characterization methods, this work presents a study of the calibration temperatures influence on the Non-Uniformity Correction (NUC) quality by comparing uniformity, bad pixel number, NETD and SiTF values during characterizations.