Unit of enery after taking FFT of velocity data
5 visualizzazioni (ultimi 30 giorni)
Mostra commenti meno recenti
Dear all,
I was taking the fft of velocity time data. But I am confusing about the unit of energy after taking fft.
For Example:
velocity have the unit of m/s.
I take the FFT of u(t) then I get u(f). i,e u(f)=sum[u(t)exp(-j*2*pi*f*t)] and calculate the energy over frequency domain by multiplying u(f) with the conjugate of u(f). i.e.
E(f)=u(f)*conj(u(f))
Then my question is what is the unit of E(f). Is that m2/s or m2/s2.
and what is the unit of u(f)?? Is that m/s or m.
Could anybody clear me about the above problem and give me some reference.
Thanks
Pavel
0 Commenti
Risposte (1)
Thomas Koelen
il 11 Mag 2015
It's still a velocity. If you do a continuous Fourier transform, you go from signal to signal integrated over time, which is signal per frequency, but in a discrete Fourier transform you're just summing discrete velocities with coefficients, and the result is still a velocity.
Vedere anche
Community Treasure Hunt
Find the treasures in MATLAB Central and discover how the community can help you!
Start Hunting!