Removing DC component at 0 HZ from acceleration data after fft
29 visualizzazioni (ultimi 30 giorni)
Mostra commenti meno recenti
Adam Levschuk
il 29 Mag 2020
Commentato: Nidhi Singh
il 11 Feb 2022
Hello,
After i compute the FFT of my acceleration data (Fs = 50 Hz) i am getting a large spike at 0 Hz (the leftover DC component). I have tried subtarcting the mean and detrending my data (detrend(X,2)).
Here is my code:
n = length(acc(:,1));
accX_fft = fft(acc(:,1),n);
PSD = accX_fft.*conj(accX_fft)/n;
freq = linspace(0,50,length(accX_fft));
L = 1:floor(n/2);
plot(freq(L),PSD(L));
The amplitudes of the frequecieis i want to visualize are already very very small, so the spike at 0 Hz is really distorting the view.
Id appreciate any reccomendation on how to get rid of this spike.
2 Commenti
Ameer Hamza
il 29 Mag 2020
If subtracting mean does not work, then it might be some other frequency?
Nidhi Singh
il 11 Feb 2022
I am having the same doubt. If subtracting the mean doesn't work, than can we use high pass filter here with fft graph?
Risposta accettata
Ameer Hamza
il 29 Mag 2020
As described here: http://blog.originlab.com/how-to-remove-dc-offset-before-performing-fft try using a high-pass filter to remove very low frequencies from your signal. See highpass(): https://www.mathworks.com/help/releases/R2020a/signal/ref/highpass.html
2 Commenti
Più risposte (0)
Vedere anche
Categorie
Scopri di più su Bartlett in Help Center e File Exchange
Community Treasure Hunt
Find the treasures in MATLAB Central and discover how the community can help you!
Start Hunting!