为了求解多波长高温计多光谱通道的欠定方程组,引入了优化的思想,将多光谱真温的求解问题转化为多目标极值优化(MMO)问题,无需假设光谱发射率与其他物理量之间的函数关系模型即可求解真温。所提方法的反演精度与二次测量(SMM)法的大体相同,但反演速度大幅增大。借助火箭尾焰的真实测量数据,利用MMO法实现了火箭尾焰真温和光谱发射率的反演。

在多波长温度测量系统中, 光谱发射率假设为波长或温度模型来实现真温的求解。由于模型假设存在一定的不确定性, 光谱发射率模型与实际光谱发射率的变化规律可能不符, 会造成较大的真温反演误差。另外, 光谱发射率与波长或温度之间的函数关系通用性较差, 尤其是待测辐射体发生改变时, 这种关系自然也就不复存在了。为了获得正确的真温, 首次将优化思想引入到方法中, 建立了单目标极小值优化法(Single Objective Minimization Optimization Method, SMO)完成真温反演。新方法无需建立光谱发射率和波长或温度之间的模型, 降低了真温求解方法的复杂性和技术难度。与原有的光谱发射率与温度之间的模型(也称二次测量法, Second Measurement Method, SMM法)相比, 在相同的初始条件下, 新方法与二次测量法相比, 反演速度提高了95%以上。

基于多光谱辐射测温技术，提出一种无需假设发射率模型的梯度投影算法，并对6 种发射率模型进行了仿真计算。结果表明：梯度投影法反演结果误差小于20K，发射率反演结果的趋势与模型吻合。梯度投影法属约束优化算法，与多光谱辐射测温技术结合可避开发射率无法确定需要假设模型的难题，开辟了多光谱辐射测温新的研究思路。

对于2 000 K以上的温度场, 采用热像仪对温度场进行检测时, 由于热像仪存在饱和问题, 所以采用热像仪重建温度场这种测量的方法已不再适用。利用多组光学探头通过光纤远传, 实现多光谱多通道数据的测量。在无需预先假设发射率与波长之间的模型关系基础上, 通过迭代算法获得表面某些点的真温。通过布置成十字测温结构的多光谱方法实现涡轮增压锅炉多点温度的测量, 构建了整个高温温度场的温度分布。结果表明: 该方法用来测量高炉温度场分布可行、预测误差较小, 可以为高温温度场的分析诊断提供参考。

在高温温度场重建过程中，仍然需要通过温度场的单点温度值来构建整个温度场的温度分布情况。以焊接温度场为例，通过反距离加权法、克里格法和样条函数法三种插值方法，分别对其空间变异和布局进行了分析和重建。结果表明：不同插值方法对预测精度影响不显著，而采样点数量则显著影响了温度场空间分布的重建精度。在温度场重建过程中，25个采样点进行重建是比较适宜的采样数量。将得出的结论与最佳采样公式进行比较，发现使用公式计算的最佳采样数量相对偏低，说明不考虑采样点实际的空间变异情况，仅使用最佳公式得到的采样数量进行温度场的重建会导致重建结果的不准确。

A piece-wise transition detection algorithm that performs displacement measurements for self-mixing sensors is developed. The algorithm can correctly detect self-mixing fringes at a low signal-to-noise ratio in the presence of disturbances without filtering. Displacement reconstructions by the phase unwrapping method based on this algorithm are experimentally validated, with laser subject to the moderate feedback regime.

A novel broadband transmission method to determine polymer film thickness during manufacturing is proposed, and a measurement system is developed based on this method. The relationship between broadband optical power and film thickness is deduced according to the Lambert–Beer law. The system is composed of a halogen light and an optical power meter. Results show that the measurement error of this method is approximately 1 \mm m, and the resolution of the system is below 0.4 \mu m for polymer films with less than 100-\mm m thickness.

An alternative technique for infrasound detection based on the self-mixing (SM) interference of a laser diode is described. The principle involved is the dependence of the power emitted by the laser diode on infrasound-induced membrane vibration. The Fourier transform and fringe-counting methods are used to analyze the self-mixing signal. Infrasound signals are experimentally measured from 2 to 20 Hz with a resolution of 0.25, and the results well agree with the theoretical ones.

The channel output of a multi-wavelength pyrometer is the brightness temperature rather than the true temperature. Twice recognition method is put forward to change the brightness temperatures of a multi-wavelength pyrometer into the true temperatures of targets. Using the data offered by Dr. F. Righini, the experimental results show that the difference between the calculated true temperature based on twice recognition method and the real true temperature is within +-20 K. The method presented in this paper is feasible and effective for the true temperature measurement of targets.

In total light scattering particle sizing technique, the relationship among Sauter mean diameter D32, mean extinction efficiency Q, and particle size distribution function is studied in order to inverse the mean diameter and particle size distribution simply. We propose a method which utilizes the mean extinction efficiency ratio at only two selected wavelengths to solve D32 and then to inverse the particle size distribution associated with Q and D32. Numerical simulation results show that the particle size distribution is inversed accurately with this method, and the number of wavelengths used is reduced to the greatest extent in the measurement range. The calculation method has the advantages of simplicity and rapidness.