Pitfalls in the FFT
This is a summary of the pitfalls that plague the FFT analysis technique. This is not to say that FFT analysis is no good -- on the contrary, it has revolutionized the analysis of vibration data. The important fact is that the problems with FFT analysis can be overcome by proper technique, and the residual effects that remain can be reduced to insignificant levels.
Sampling causes aliasing
Time limitation causes leakage
Discrete frequencies in the calculated spectrum causes the picket fence effect.
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