15 November 2022 in IEEE Sensors Journal
This article establishes a behavior model for analyzing the temperature-dependent fixed pattern noise (TD-FPN) induced by pixel passive and active resistance for uncooled bolometric thermal imagers. A model-based two-point correction method is also proposed to compensate for the TD-FPN by using the ratio of passive and active resistance. An infrared imaging system based on a $640\times512$ readout chip is implemented to verify the proposed model and the model-based correction method. The comparison between the simulation and measurement results shows the model’s accuracy. The residuals after the model-based correction are within ±25 LSBs, which is considerably lower than the traditional method’s residuals. Due to the low residuals, the spatial noise equivalent temperature difference (S-NETD) is less than 100 mK within the temperature range of [−40 °C to 80 °C]. The proposed model and the correction method enable uncooled bolometric thermal imagers to achieve low-cost and wide-temperature-range shutter-less operation.