基于最小二乘图像坐标修正的中阶梯光谱仪谱图还原算法  

Spectral reduction algorithm for echelle grating spectrometer based on least-squares image coordinate correction

作　　者：欧阳羽轩 傅骁[1] 段发阶[1] 王宽[1] 吴靓昕 Ouyang Yuxuan;Fu Xiao;Duan Fajie;Wang Kuan;Wu Jingxin(The State Key Lab of Precision Measuring Technology and Instruments,Tianjin University,Tianjin 300072,China;China Aerospace Hunan Power Machinery Research Institute,Zhuzhou,Hunan 412002,China)

机构地区：[1]天津大学精密测试技术及仪器全国重点实验室,天津300072 [2]中国航发湖南动力机械研究所,湖南株洲412002

出　　处：《光电工程》2024年第7期125-138,共14页Opto-Electronic Engineering

基　　金：国家自然科学基金资助项目(U2241265,92360306,52205573,61971307,62231011);航空科学基金项目(2022Z060048001);中国博士后科学基金项目(2022M720106);装备预研教育部联合基金项目(8091B022144);国防科技重点实验室基金项目(6142212210304);广东省重点研发计划项目(2020B0404030001);霍英东教育基金会资助项目(171055);青年人才托举工程(2021QNRC001)。

摘　　要：中阶梯光谱仪具有交叉色散特征,二维谱图还原是决定其波长测量准确性的关键环节,但是环境变化、加工装调等引起的光斑坐标变化对谱图还原精度造成严重影响。本文提出了一种基于最小二乘图像坐标修正的中阶梯光谱仪谱图还原算法,首先提取校准汞灯光源多波长光斑质心坐标,利用理论像点和实际像点坐标构建系数矩阵,通过最小二乘法估计获得二维像面的平移、缩放、旋转系数,再采用多项式拟合减小残差影响,实现不同波长光斑的图像坐标修正,进而实现波长精确解算。实验结果显示,该算法能有效提高中阶梯光谱仪的谱图还原精度,在模拟较大装调误差条件下,修正后坐标与理想坐标偏差小于0.6个像元,证明了该算法具有较高的精度。The echelle grating spectrometer has cross-dispersion characteristics,and two-dimensional spectral map reduction is the key link to determine its wavelength measurement accuracy,but the changes of spot coordinates caused by environmental changes,processing and mounting have a serious impact on the accuracy of spectral map reduction.In this paper,a spectrum reduction algorithm based on least-squares image coordinate correction is proposed for the middle-step spectrometer.Firstly,the center-of-mass coordinates of the multi-wavelength spot of the calibrated mercury lamp light source are extracted,and the coefficient matrix is constructed by using the theoretical and actual image point coordinates.The translation,scaling,and rotating coefficients of the two-dimensional image plane are obtained by the least-squares estimation method,and then a polynomial fitting is adopted to reduce the influence of residuals,to achieve the correction of the image coordinates of the spot at different wavelengths,and then achieve the accurate resolution of wavelength,and realize the wavelength accurate solving.The experimental results show that the algorithm can effectively improve the spectral image reduction accuracy of the middle-step spectrometer,and the deviation of the corrected coordinates from the ideal coordinates is less than 0.6 image element under the condition of simulating larger mounting errors,which proves that the algorithm has high accuracy.

关 键 词：光谱学 光谱仪 二维光谱图 质心提取 谱图还原 

分 类 号：O433.4[机械工程—光学工程]