- more time-domain elements --> finer frequency domain spacing.
- treating the three cuts the same will introduce an artificial phase from the time delay
- keeping track of factors and frequencies from fft is not trivial. For this reason, I recommend keeping the number of elements the same whenever possible (so, window vs cut)
- There are more complex methods that do a better job of giving time-resolved frequency information. The continuous wavelet transform (CWT) may or may not require significant deviaton from the default parameters, but it's worth a quick test at least
Does FFT output vary if I split a signal into windowed time segments instead of using a Hanning Window?
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I have a pressure signal vs time. The pressure signal has been recorded for 15 minutes. I would like to find the frequency distribution of this signal over time. To do this, I split the pressure signal into 3 segments of 5-minutes (300-seconds) and applied FFT to each of them separately for which I have obtained respective outputs. I have 2 questions:
Q1: If I use a Hanning window to this same signal and apply the FFT for those 3 segments, will I see a difference in the outputs?
Q2: Is my method of manually splitting the signal, wrong? If so, could you please elaborate?
I understand that I should implement this, but I would like to discuss the potential implications of this technique.
Please help. Thank you.
Sindar on 19 May 2020
A few things to consider: