Performance Study of Thermal Control for Uncooled IRFPA Cores in Quantitative Detection in Complex Environments

Objective: Uncooled infrared focal plane arrays (IRFPAs) have been widely applied due to their advantages of operation without cryogenic cooling, compact size, low power consumption, and long lifespan. However, their high sensitivity to ambient temperature constrains the accuracy and stability of quantitative imaging detection in complex environments, such as industrial gas leakage infrared imaging detection and division-of-focal-plane polarization imaging. Traditional temperature compensation and non-uniformity correction (NUC) algorithms also struggle to completely suppress residual thermal drift and noise. Therefore, in-depth research on the variation patterns of uncooled IRFPA imaging performance with temperature changes and investigation of high-precision temperature control technology and the corresponding NUC algorithms are of significant importance for enhancing infrared quantitative imaging detection capabilities in complex environments. Methods: This study presents the design and implementation of a high-precision active temperature control system based on a thermoelectric cooler (TEC) that enables precise adjustment of uncooled IRFPA assembly temperature within a wide operating range of 15–42 °C and achieves stable temperature control with ±0.01 °C accuracy. A series of experiments were conducted under both thermally stabilized and free-running conditions to characterize the effect of temperature on the IRFPA’s response parameters (gain, offset) and 3D noise profile, including system performance validation, multi-temperature response analysis, and assessments of repeatability and stability. Furthermore, through experiments with filter-wheel multispectral IRFPA imaging systems and division-of-focal-plane polarization thermal imaging systems, we validated the effectiveness of the stray radiation model-based NUC algorithm (SRM-TUIRF) considering temperature control conditions and the comprehensive correction algorithm for thermal drift in division-of-focal-plane polarization thermal imaging (CCMTD), respectively. Results and Discussions: The TEC-based temperature control system achieved high-precision temperature stabilization of ±0.01 °C across a wide temperature range of 15–42 °C, providing a technical guarantee for stable operation of uncooled IRFPA in complex environments. Experiments revealed that IRFPA gain exhibited a negative correlation with focal plane temperature, offset showed a positive correlation with core temperature, and temperature transition-triggered shutter correction caused synchronous updates of response parameters. The temperature control system significantly improved IRFPA noise performance and response stability. Under TEC-stabilized 24 °C operation, temporal noise was reduced from 14.55 to 11.82, while spatial noise was drastically suppressed from 469.2 to 8.93, demonstrating a substantial reduction in 3D noise. The relative errors of the repeated tests did not exceed 0.42%, and 24-hour long-term stability errors remained below 1.51%, indicating excellent operational reliability. For the filter-wheel multispectral IRFPA imaging systems, the temperature-controlled SRM-TUIRF algorithm effectively overcame internal stray radiation interference caused by environmental temperature fluctuations. The root mean square error (RMSE) for all six spectral channels was significantly reduced, with correction performance superior to traditional two-point correction and fixed pattern noise correction methods. This approach is particularly suitable for low-frequency stray radiation suppression in outdoor environments with large temperature variations. It significantly enhances multispectral image uniformity and detail representation. For the division-of-focal-plane polarization thermal imaging systems, combining the temperature control system with CCMTD reduced the maximum measurement errors of degree of linear polarization (DoLP) and angle of polarization (AoP) by 33.89% and 72.97%, respectively, achieving accurate and stable measurement of polarization parameters across a wide range of operating temperatures. Conclusions: By employing a high-performance uncooled IRFPA active temperature control system, this study systematically analyzed the variation patterns of uncooled IRFPA system performance with core temperature changes, demonstrating that active temperature control is an effective means to suppress thermal drift and reduce noise in uncooled IRFPA imaging systems. It provides a stable and reliable physical foundation for advanced NUC algorithms that depend on precise temperature parameters, serving as a key enabling technology for unleashing advanced algorithm performance. The combination of temperature control systems and novel correction algorithms can provide technical support for uncooled IRFPA applications in complex environments such as industrial gas leakage multispectral infrared imaging detection, epidemic mobile population imaging temperature screening, and division-of-focal-plane polarization imaging for quantitative imaging applications. This research provides reliable experimental evidence and technical pathways for promoting the development of uncooled IRFPA imaging technology from traditional qualitative observation to high-precision, high-reliability quantitative detection applications.