Three-point infrared radiometric calibration and correction method using U-shaped blackbody

Infrared focal plane array (IRFPA) is an important component of the thermal imaging system. However, due to facts like technical limitations and material defects in production, the environmental influence, and too long time operation, etc., the drift of the IRFPA response during their working is unavoidable. It affects the image quality of the thermal imaging systems and has negative effects on the precision of the thermal imaging equipments. Aiming to solve the problems of traditional radiation calibration and correction methods, considering the nonlinear response of infrared detectors, and taking advantage of the infrared imaging integral platform based on U-shape blackbody, a three-point infrared calibration and correction technology was discussed. Furthermore, the previous tow-point calibration and correction method was used for comparison. The experimental results show that during the temperature range of 25-65°C, compared with the original calibration precision, the three-point calibration technology owns quite an effective consequence with the biggest absolute error of 0.126 6 K and average error of -0.048 8 K. However, the method proposed does not have quite abvious difference with the tow-point method, so generally the tow-point calibration and correction can adapt the normal radiometric calibration application.