How to do a FFT on an accelerometer?
EDIT: A little bit of code: So essentially, ive performed a FFT on my accelerometer data, giving Sz, filtered high frequencies out using a simple brick wall filter (I know its not ideal). Then ive use omega arithmetic on the FFT of the data.
How is noise and signal attenuated in FFT?
Basically, the noisy signal (signal + noise) is attenuated over the frequencies where the noise is expected to be grater than your signal, and it is amplified where your signal is expected be grater than your noise. However, I would suggest more modern approaches that use non-linear processing, for example wavelet denoising.
How is the amplitude of the FFT related to its magnitude?
The FFT returns a two-sided spectrum in complex form (real and imaginary parts), which you must scale and convert to polar form to obtain magnitude and phase. The frequency axis is identical to that of the two-sided power spectrum. The amplitude of the FFT is related to the number of points in the time-domain signal.
How to pick the correct filter for accelerometer data?
If y is the noisy signal and x is the signal to be estimated, the function to be minimized is μ ‖ x − y ‖ 2 + ‖ D x ‖ 1, where D is the finite differences operator. The problem is that your noise has a flat spectrum. If you assume white Gaussian noise (which turns out to be a good assumption) its power spectrum density is constant.
Why do I cut off the DC signal after FFT?
Because all your data on left are above 0, for frequency analyze it is a DC signal. So after your fft, it abstract the DC signal out, it is very hugh. For your scene, you only need to cut off the DC signal, just preserve the signal over 0 Hz (AC signal), that makes sense.
Which is the best way to use FFT?
FFT has produced some interesting results. One of my attempts was to FFT the acceleration signal, then render low frequencies to have a absolute FFT value of 0. Then I used omega arithmetic and inverse FFT to gain a plot for velocity. The results were as follows: Is this a good way to go about things?