透射式能见度仪定标光源光谱模拟方法

Spectral Simulation Method for Calibration Light Source of Transmissometers

透射式能见度仪的校准结果无法溯源到世界气象组织对气象光学视程(MOR)的定义,如何实现MOR定义中2700 K白炽灯的光谱模拟已成为透射式能见度仪定标技术亟待解决的关键问题,故对透射式能见度仪定标光源的光谱模拟方法进行了研究。首先,从理论上分析了光谱不匹配对透射式能见度仪定标的影响,建立了满足透射式能见度仪定标精度要求的光源光谱分布判别依据,得出透射式能见度仪定标光源的光谱模拟误差应优于±5.5%的结论。然后,基于一种数字微镜器件(DMD)的透射式能见度仪定标光源系统,在遗传算法基础上,提出了一种基于无余均分机制的光谱模拟方法,以均分800列DMD微镜阵列面为前提,通过不断均匀划分DMD阵列面的方式增加光谱拟合单元数量,实现了2700 K绝对色温的光谱模拟。最后,测试了20,50,80个基础光谱拟合单元对应的定标光源的光谱分布,并进行了不确定度分析。测试结果表明,80个基础光谱拟合单元对应的定标光源光谱模拟误差为±5.3%,扩展不确定度为4.04%。

The calibration results of the transmissometers cannot be traced to the definition of meteorological optical range(MOR)of the World Meteorological Organization.How to realize the spectrum simulation of the 2700 K incandescent lamp in the MOR definition has become a key issue that needs to be solved urgently in the calibration technology of the transmissometers,so the spectral simulation method of calibration light source of the transmissometers is studied.First,the influence of spectral mismatch on the calibration of the transmissometers is analyzed theoretically,and the basis for discriminating the spectral distribution of the light source that meets the calibration accuracy requirements of the transmissometers is established.It is concluded that the spectral simulation errors of the calibration light sources of the transmissometers should be better than±5.5%.Then,based on a transmissometer calibration light source system with digital micromirror device(DMD),and on the basis of genetic algorithm,a spectral simulation method based on a uniform division mechanism without residues is proposed.On the premise of dividing uniformly the array surface of DMD micro mirrors into 800 columns,the number of fitting units is increased by uniformly dividing the DMD array surface,and and the spectral simulation of absolute color temperature of 2700 K is realized.Finally,the spectral distribution of the calibration light source corresponding to 20,50,and 80 basic spectral fitting units is tested,and the uncertainty is analyzed.The test result show that the spectral simulation error of the calibration light source corresponding to the 80 basic spectral fitting units is±5.3%,and the expanded uncertainty is 4.04%.