Key Laboratory of Industrial Informatics, Shenyang Institute of Automation, Chinese Academy of Sciences, Shenyang 110016, People's Republic of China.
Appl Spectrosc. 2013 Sep;67(9):1087-97. doi: 10.1366/12-06822.
Spectral peak overlapping is a basic problem in analytical data processing of laser-induced breakdown spectroscopy (LIBS). Curve fitting is the typical method of resolving overlapped peaks. For preventing ambiguous fitting, appropriate initial values must be known. The aim of this work was to present a method that could be used to determine appropriate initial values of the curve-fitting method by using fractional differential theory. According to the variation of characteristic points of Lorentzian peaks at different fractional differential orders, parameter estimators were obtained that were used to calculate the initial values of the curve-fitting method. As it is a widely used optimization method, the Levenberg-Marquardt method was used in curve fitting. Simulation and LIBS experimental results proved that the proposed method of the initial value estimation can effectively resolve the overlapped peaks in LIBS data processing.
光谱峰重叠是激光诱导击穿光谱（LIBS）分析数据处理中的一个基本问题。曲线拟合是解析重叠峰的典型方法。为了防止拟合不明确，必须知道适当的初始值。本工作的目的是提出一种可以利用分数微分理论确定曲线拟合方法适当初始值的方法。根据洛伦兹峰特征点在不同分数微分阶数下的变化，得到了用于计算曲线拟合方法初始值的参数估计值。由于该方法是一种广泛使用的优化方法，因此在曲线拟合中使用了 Levenberg-Marquardt 方法。模拟和 LIBS 实验结果证明，所提出的初始值估计方法可以有效地解析 LIBS 数据处理中的重叠峰。
