Chemometrics description of measurement error structure: study of an ultrafast absorption spectroscopy experiment.

The error structure inherent to a transient absorption spectroscopy kinetic experiment is described through the examination of the related measurement error covariance matrices in the time and the spectral direction. The systematic approach proposed by Wentzell's group to characterize the measurement error covariance matrices is used for this purpose. The goals of this study are identifying and modelling the factors contributing to the error measurement and proposing a weighting error-based scheme that can be generally used when analysing data coming from this experimental setup. From the analysis performed, independent noise structure is associated with the time direction of the data sets, whereas the spectral direction is affected by two sources of correlated errors, which can be related to the probe spectrum and to the mean signal registered.