Temperature-controlled uncooled IRFPA non-uniformity correction based on a stray radiation model of optical filter

Uncooled Infrared Focal Plane Arrays (IRFPAs) are widely utilised in various applications, such as security, public health and gas leak detection. However, their application in detecting weak signals is constrained by inherent drawbacks, including low sensitivity, poor output stability and severe non-uniformity. Based on a fixed-pattern noise (FPN) model for a narrowband optical filter within the IRFPA imaging path, we integrate a thermoelectric cooler (TEC) system and its temperature parameters to establish the stray radiation model of a temperature-controlled uncooled IRFPA imaging system with an optical filter (SRM-TUIRF). Subsequently, we propose a novel non-uniformity correction (NUC) method based on the developed internal radiation model. The proposed method only requires the temperature readings of the focal plane, optical filter and lens to simulate the prior distribution of the internal stray radiation of the imaging system, thereby improving the accuracy and speed of NUC. Validation via room-temperature radiometric calibration shows that the simulated and measured stray radiation are in close agreement, with a relative error of less than 1.15%. Further experiments under varying high- and low-temperature scenarios, both indoors and outdoors, demonstrate that the proposed method effectively performs NUC over a wide ambient temperature range. The proposed approach successfully addresses the thermal drift problem in uncooled IRFPA imaging systems, ensuring stable, high-quality imagery, thereby verifying the effectiveness and robustness of the proposed method.