For a real-world system of oscillating mechanical components, what kinds of frequencies should I seek in DFT?

1. How do you calculate power spectral density from FFT?
2. Why is FFT needed?
3. What does the amplitude of FFT mean?
4. What is power spectrum analysis?

How do you calculate power spectral density from FFT?

A PSD is computed by multiplying each frequency bin in an FFT by its complex conjugate which results in the real only spectrum of amplitude in g².

Why is FFT needed?

The FFT algorithm is heavily used in many DSP applications. It is used whenever the signal needs to be processed in the spectral or frequency domain. Because it is so efficient to implement, sometimes even FIR filtering functions are performed using an FFT.

What does the amplitude of FFT mean?

The amplitude of the FFT is related to the number of points in the time-domain signal. Use the following equation to compute the amplitude and phase versus frequency from the FFT. where the arctangent function here returns values of phase between –π and +π, a full range of 2π radians.

What is power spectrum analysis?

Power spectrum analysis is a technique commonly used by PID tuning software and applies a fast Fourier transform (FFT) to the variation of a particular signal to compute its frequency spectrum. The result is presented as a plot of signal power against frequency and is referred to as its power spectrum.