The Fourier transform is well suited only to the study of stationary signals where all frequencies have an infinite coherence time, or – otherwise expressed – the signal’s statistical properties do not change over time. Fourier analysis is based on global information which is not adequate for the study of compact or local patterns.You can find a free pdf of this book here: http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.122.8536&rep=rep1&type=pdf
Wednesday, June 19, 2013
Fourier transforms are not good for analyzing nonstationary signals
I'm currently thumbing through parts of "Image Processing and Data Analysis: The Multiscale Approach." In Chapter 1, I found this enlightening comment on the Fourier transform: