Long-Range Multispectral Thermal Imager for Simultaneous Measurement of Distance and Temperature

The multispectral thermal imager is a cutting-edge tool for the real-time measurement of high-temperature and transient-temperature fields. It can achieve high-precision temperature distribution measurements in complex scenes by acquiring multi-spectral radiation information. However, the existing research mainly focuses on the temperature measurement function, and there is little exploration of its potential application. In this paper, the method of measuring the distance of a high-temperature target based on a multispectral thermal imager is proposed and verified for the first time, which solves the problem that the traditional ranging model cannot be accurately measured in high-temperature environments. By constructing the theoretical model of the multi-aperture optical splitting system, the internal relationship between temperature field pixel migration and target distance is analyzed, and the feasibility and applicability of the method is verified by experiments. The results show that the multispectral thermal imager can overcome the interference of high-temperature radiation to traditional ranging technology, realize high-precision temperature measurement, and obtain the target distance information simultaneously. The measurement error of 300 m is 12.09%, which can be applied to the real-time measurement of the flame temperature field.