Digital signal processing for a FT-IR spectrometer using multiple modulations

摘要

By considering a transient signal as merely another signal in a linear, shift-invariant system representing a step-scanning Fourier transform spectrometer, the present invention characterizes the transient signal and then compensates for its effect on the measurement by employing various signal processing techniques. Thus, according to one aspect of the present invention, it provides a method for obtaining the spectrum of the desired signal by subtracting the Fourier transform of the transient signal from the Fourier transform of the composite signal output from the detector (i.e., the signal containing both the desired signal and the transient signal).PPAccording to another aspect of the present invention, it provides a method for deriving an estimate of the Fourier transform of the transient signal from the Fourier transform of the composite signal.