Baseline correction method for Raman spectra based on piecewise polynomial fitting

摘要

Raman spectrum is a scattering spectrum, and its frequency, intensity and polarization can characterize the peculiar properties of materials, thus it has been widely applied in many fields. The Raman signal is so weak that the background interferes it greatly. Polynomial fitting is the simplest method of baseline correction. The order of polynomial is hard to be chosen for the whole data, because if the polynomial order is too high or too low, the accuracy of the baseline fit will be affected. This paper proposes a new approach: piecewise polynomial fitting(PPF). Segment the spectral data, and then the proper order is fitted respectively. Then we employ iterative optimization method eliminate discontinuities between segments. Simulation and experiment results show that this method has a higher accuracy.