# Research on Performance Evaluation and Optimization Theory for Thermal Microscope Imaging Systems
## 6 Conclusions  
This paper studied the imaging characteristics of the TMISs and analyzed the differences between microscopic and telescopic thermal imaging. Theoretical models of minimum resolvable temperature difference (MRTD) and minimum detectable temperature difference (MDTD) of the TMISs were established. If the performance parameters of the hardware part of the system are known, the temperature resolution of TMISs can be evaluated by simple calculations based on the model. Through the simulation analysis of the model, we have drawn new conclusions about the performance optimization theory of the thermal microscopy imaging system:  
1. In the case of the same infrared detector components, the temperature resolution of the TMISs decreases as the magnification increases.
2. IPD maintains high temperature resolving ability in both medium-wave infrared thermal imaging and long-wave infrared thermal imaging in a low background temperature environment.
3. The use of medium-wave infrared can make the system have a higher temperature resolution ability than using long-wave infrared.
4. The use of long-wave infrared can make the system more sensitive to the non-uniformity of the emissivity. It has a higher sensitivity for observing natural objects that do not generate heat with a small difference in emissivity, and it is easier to obtain the difference in target emissivity.
5. Lowering the imaging frame rate can reduce the MRTD and MDTD of the system, so it can improve the temperature resolution of the TMISs.
6. In addition to the detector type, wavelength band, optical design, and other factors, it is also necessary to set the appropriate operating environment temperature for different systems to achieve a higher temperature resolution.  
In addition, we built a high-performance thermal microscope imaging system based on the theoretical research results. Through comparative experiments, it was proved that the system we built has high performance and demonstrates the effectiveness of the theoretical research in this paper.  
In this paper, through the research on the performance evaluation theory of TMISs, the theoretical results about the performance evaluation and optimization of TMISs are obtained, and the theoretical results are applied to practical applications to build a high  
Figure 13: Experimental result. (**a**) low-resolution thermal microscope image (SNT = 5.4627); (**b**) Bi-linear amplification image (SNT = 5.6503); (**c**) Micro-scan reconstructed image (SNT = 5.7148).  
performance thermal microscope imaging system. The results of this research can be applied to the design of TMISs in the future, and can guide designers to build high-performance TMISs based on different hardware conditions and application environments. In addition, the conclusions about optimizing system performance are also applicable to other thermal imaging systems.  
Formal analysis, B.Z.; Investigation, B.Z.; Project administration, M.G.; Resources, Q.C. and Q.Y.; Validation, M.G.; Visualization, Y.S.; Writing-original draft, B.Z.; Writing-review & editing, P.L.R., X.S. and Q.Y. All authors have read and agreed to the published version of the manuscript.  
This work was supported by National Nature Science Foundation of China (61971373) and National Key Research and Development Plan (2019 YFC1407904) and Natural Science Foundation of Hebei Province-China (F2019203440, C2020203010) and the Science and Technology Support Projects of R&D Plans of Qinhuangdao City (Grant No. 202004A001).  
Not applicable.  
The authors declare no conflict of interest.