Multispectral light-field thermometry system for high-temperature surfaces under intense background interference

Accurate temperature assessment in complex combustion environments is crucial for the thermal diagnostics of aero-engines and gas turbines. To address the challenges posed by intense ambient radiation, a background-corrected multispectral light-field (MSLF) thermometry framework is developed. The system integrates single-snapshot 4D acquisition with an emissivity-adaptive model. A dual strategy is employed to mitigate radiative interference: a background-correction algorithm eliminates reflection artifacts, while discrete, narrowband wavelengths (specifically 700, 750, 800, and 850 nm) are selected to spectrally bypass gaseous radiation. Validation in a heating furnace demonstrates that reflection-induced errors can be reduced to within 6.5 K. Furthermore, jet-flame impingement tests confirm that absolute deviations were limited to within 20 K across varying emissivities (0.2–0.9), ensuring robust performance in high-temperature environments.