Nonuniformity correction of infrared focal plane arrays

Abstract

The non-linearity of the responsivity of infrared (IR) focal plane arrays (FPA) is a major concern when IR images are evaluated. This will affect both the detection and classification ability of the IR sensor. The nonuniformity correction (NUC) method proposed here is based on polynomial fitting to pixel responsivities. It is applied to infrared data obtained from two cooled multi-band sensors in the MWIR region. The method is shown to give both suitable data restoration and a simple and efficient computer implementation. Bad pixels were identified by evaluating the coefficents obtained from the multi degree polynomial. Bad pixels were also replaced by using a nearest neighbour-hood algorithm. The NUC method, including the bad pixel identification and replacement, was implemented in a user friendly GUI (graphic user interface) for calibration of registered IR data.