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High-precision multi-spectral radiation thermometry method based on the improved gray wolf optimization algorithm
Optics Letters
|April 15, 2025
Summary
This comment discusses multi-spectral thermometry (MST). It highlights that without emissivity assumptions, accurately determining temperature and emissivity from spectral data is mathematically impossible, leading to potential inaccuracies.
Area of Science:
- Optics and Photonics
- Thermodynamics
- Metrology
Background:
- A recent publication introduced a multi-spectral thermometry (MST) method.
- The method claims high precision without emissivity assumptions.
Purpose of the Study:
- To critically evaluate the claims of a novel multi-spectral thermometry (MST) method.
- To address the fundamental limitations of emissivity-free temperature and emissivity determination.
Main Methods:
- Theoretical analysis of multi-spectral thermometry (MST) principles.
- Examination of the mathematical relationship between spectral radiance, temperature, and emissivity.
Main Results:
- The study demonstrates that without any hypothesis on emissivity, the determination of both the true emissivity spectrum and temperature is ill-posed.
- An infinite number of exact solutions exist, making unique extraction impossible without additional information or assumptions.
- This inherent ambiguity can lead to significant inaccuracies or bias in temperature measurements.
Conclusions:
- The claim of a highly precise emissivity-free MST method is challenged.
- Accurate thermometry requires either prior knowledge or simultaneous determination of the emissivity spectrum.
- The presented comment underscores the importance of addressing emissivity in spectral temperature measurement techniques.

