Origins of Baseline Drift and Distortion in Fourier Transform Spectra

Abstract

The spectrum scanned by a Fourier transform spectrometer (FTIR) often has a baseline drift. However, baseline distortion rarely occurs in a laboratory owing to the insignificant effects of environmental vibrations and electromagnetic factors. Even if it occurs, the distorted spectrum can be manually eliminated. However, in a complex environment, especially after the long-term operation of a spectrometer, the scanned spectrum may be distorted to different degrees. Herein, the origins of spectral baseline drifts and distortions are analyzed and simulated using MATLAB; furthermore, a baseline correction method based on the baseline-type model is proposed. The results of experiments performed on the methane spectrum confirm that the proposed method outperformed the improved modified multi-polynomial fitting and iterative averaging methods.

How to Measure Polymer Degradation? An Analysis of Authors' Choices When Calculating the Carbonyl Index

“…From all 95 papers, 5 cited they performed a step of baseline correction, although with no details and only 1 work described the details of the baseline. For a detailed discussion on the precautions and care about baseline correction and usage, we refer to the works of Zhang et al, Almond et al, and Yang et al…”

An adaptive extended Gaussian peak derivative reweighted penalised least squares method for baseline correction

“…where w i is the weight of the ith wavelength and the weight matrix W = diag{w 1 ,w 2 ,/,w M }. Deriving the objective function Q of eqn (7) and making it zero yields eqn (8). Solving eqn (8), the tted baseline is nally obtained, as shown in eqn (9).…”

“…Deriving the objective function Q of eqn (7) and making it zero yields eqn (8). Solving eqn (8), the tted baseline is nally obtained, as shown in eqn (9).…”

“…[4][5][6][7] Spectral data usually contain baseline dri due to changes in the measurement environment, and the inuence of the instrument itself. 8,9 Baseline dri can lead to serious measurement errors and deteriorate the results of qualitative and quantitative analyses. Baseline correction (BC) can remove baseline dri from spectral data by mathematical means.…”

Quantitative analysis method for the Fourier transform Infrared spectroscopy of gases

“…The spectra scanned by the spectrometer need to be pre-processed, variables selected and modeled to analyze the concentrations of the gases. Effective pre-processing is an essential step to eliminate the noises and baseline drifts of the spectra, which can improve the spectra's Signal-to-Noise Ratios (SNRs) and the sensitivity and accuracy of the measurements [8]. Variable selection can screen out the variables that represent the characteristics of the raw data, which essentially reduces the amount of data, improves computational efficiency, and makes the modeling more stable and efficient.…”