Patent ID: 6415233
Filing Date: 2002-07-02
Classification: G01J

Abstract:
A method for performing a classical least squares estimation of the value of at least one source of spectral variation of a sample comprising:utilizing a previously constructed calibration data set wherein the constituents of such calibration data set include at least one of the sources of spectral variation that affect the optical response of the sample to be measured, such calibration data set yielding a matrix {circumflex over (K)} representing the combination of the vectors containing the at least one spectral shape of the measured sources of spectral variation; measuring the optical response of a sample set that contains the at least one of the sources of spectral variation in the calibration data set and at least one additional source of spectral variation whose value was not represented in the original calibration data set, said measurement forming a prediction data set; adding at least one vector representing a spectral shape that is representative of the at least one additional source of spectral variation in the prediction data set to the matrix {circumflex over (K)} to form an augmented matrix {tilde over ({circumflex over (K)})}; and estimating the value of the at least one of the sources of spectral variation in the calibration data set or the at least one additional source of spectral variation in the sample by a classical least squares prediction utilizing the augmented matrix {tilde over ({circumflex over (K)})}, wherein the at least one additional source of spectral variation is a non-baseline source of spectral variation.