光学与光电技术, 2017, 15 (1): 49, 网络出版: 2017-02-23
时间调制型FTIR光谱仪辐射度定标方法的研究
Research on Radiometric Calibration Methods of Time Modulation Based FTIR
时间调制 辐射度定标 多点非线性定标 普朗克曲线 time modulation radiometric calibration multipoint calibration the planck curve
摘要
辐射度定标是时间调制型FTIR数据处理中非常关键的一个环节,定标的好坏直接影响着其在应用中性能的优劣。根据光谱仪响应函数(线性或非线性)的不同,辐射度定标方法可分为线性定标和非线性定标; 根据定标中采用的点数的不同可分为两点定标和多点定标。首先用MATLAB对光谱仪采集的数据进行线性度分析与仿真,然后用C++编程分别实现线性定标和非线性定标。实验结果为两点法的误差为0.1118,抛物线法的误差为0.1684,四点线性的误差为0.0599。结果表明多点线性的定标方法效果最好。采用四点线性的方法进行定标将大大提升光谱的准确度,为后面的光谱识别工作打好基础。
Abstract
Radiometric Calibration is a pivotal step of spectral data processing, which directly decides the performance of FTIR. According to the different instrument functions of FTIR (linear or nonlinear), there are linear calibration and nonlinear calibration. According to the different numbers of points used in calibration, there are double point calibration and multipoint calibration. Linearity analysis of the spectral data produced by FTIR was done with MATLAB and the algorithm implementation of linear/nonlinear calibration methods was completed with C++. As the result shows, multipoint linear calibration works better than the other methods. The errors of double-point, parabola, and four-point method are 0.111 8, 0.168 4 and 0.059 9. As the result shows, multipoint linear calibration works better than the other methods. Using the four-point method can make the calibration result more accurate, which has a good influence on spectra recognition.
李雷, 张智杰, 岳松. 时间调制型FTIR光谱仪辐射度定标方法的研究[J]. 光学与光电技术, 2017, 15(1): 49. LI Lei, ZHANG Zhi-jie, YUE Song. Research on Radiometric Calibration Methods of Time Modulation Based FTIR[J]. OPTICS & OPTOELECTRONIC TECHNOLOGY, 2017, 15(1): 49.