Remote monitoring of structures by uncooled thermal infrared thermography coupled with local probes and a data management supervisor

Studying the thermal behavior of structures in outdoor conditions, using thermal infrared thermography coupled with local temperature and heat flux probes, is a multidisciplinary field of research and development. It requires to address: system design, informatics, infrared radiometry, signal and image processing, heat transfer and inverse problems domains. In the present study, we present an instrumentation solution system developed in our team to address the remote monitoring of structures in outdoor conditions and its data management. Online infrared measurement corrections, for instance due to variable atmospheric conditions at ground level, are made by using a local weather station equipped with a pyranometer. In case of failure, alternative opportunistic solutions were investigated (Toullier and Dumoulin, 2024), and various strategies of measurements corrections were studied. Comparison of surface temperature measured by infrared thermography and local probes requires to identify the emissivity of materials in the spectral bandwidth used. Such measurements can be made in laboratory but also, when studied surfaces are accessible, by using a portable emissometer. Preliminary results obtained with a 4 spectral band portable emissometer prototype, on a hybrid solar road mock-up deployed in outdoor conditions, will be presented and discussed. To complete, management of acquired data will be presented and discussed in a long term monitoring view. Conclusions on results obtained with a focus on uncooled thermal infrared data will be proposed. Perspectives will address both monitoring system but also recent progress in uncooled infrared sensors (see for instance https://project-brighter.eu/) and temperature emissivity separation algorithms (Toullier et al., 2025) for ground based monitoring systems.

References

• Toullier, J. Dumoulin, "Bias and bottlenecks study in outdoor long term thermal monitoring by infrared thermography: Leveraging opportunistic data for temperature estimation", Infrared Physics & Technology Journal, Volume 141, August 2024, 105471. https://doi.org/10.1016/j.infrared.2024.105471
• Toullier, J. Dumoulin, L. Mevel "New joint estimation method for emissivity and temperature distribution based on a Kriged Marginalized Particle Filter: Application to simulated infrared thermal image sequences", Science of Remote Sensing (2025), doi:. https://doi.org/10.1016/j.srs.2025.100209

Acknowledgments

The authors thank ANR (French National Research Agency) for supporting part of this work under Grant agreement ANR-21-CE50-0029-23 and BRIGHTER project. BRIGHTER project has received funding from the Chips Joint Undertaking (Chips JU) under grant agreement N°101096985. The JU receives support from the European Union’s Horizon Europe research and innovation program and France, Belgium, Portugal, Spain, Turkey