Why do we discard imaginary part of the phase spectrum?

1. What does the imaginary part of a signal represent?
2. What does the imaginary part of a Fourier transform mean?
3. What does the real and imaginary parts of the FFT signify?
4. Can Fourier transform be imaginary?

What does the imaginary part of a signal represent?

In signal processing "real" denotes a signal component that is in phase with (i.e. has a 0° phase shift from) some reference signal. Imaginary denotes a signal component that is in quadrature with (i.e. has a 90° phase shift from) the same reference signal. The reference signal can come from a local oscillator.

What does the imaginary part of a Fourier transform mean?

If you consider the input as current, the transfer function or Fourier transform as impedance then the output is potential. If Fourier transform is impedance, then the real part of FT is resistive part of the impedance and imaginary part is the reactive part of the impedance.

What does the real and imaginary parts of the FFT signify?

The real portion of an FFT result is how much each frequency component resembles a cosine wave, the imaginary component, how much each component resembles a sine wave.

Can Fourier transform be imaginary?

The second piece that should jump out is that the Fourier transform of the sine function is completely imaginary, while the cosine function only has real parts.