An article of manufacture comprising a program storage medium readable by a computer, the medium tangibly embodying one or more programs of instructions executable by the computer to perform a method for compensating a plurality of sequential spectra and profiles derived therefrom for effects of drift, the method comprising:
- transforming a plurality of sequential spectra obtained from a spectrometer to provide an array of drift-compensated row vectors, wherein the array of drift-compensated row vectors constitutes a drift-compensated array;
- performing a principal-factor determination on the drift-compensated array to provide a set of drift-compensated principal factors;
- and,
- generating drift-compensated scaled target-factor profiles from a profile trajectory of the drift-compensated row vectors lying within a space of drift-compensated principal factors.