What is difference between Power Spectrum and Power Spectrum Density?

[Juntack]

Hi,

My unserstanding is that

S(n) : Power Spectrum

nS(n)/RMS^2: Power Spectrum Density

What is difference between Power Spectrum and Power Spectrum Density?

Thanks in advance.

Juntack Lim

[Travis_M.]

Hello,

There is a great resource in the LabVIEW Analysis Concepts manual.  Specifically from chapter 4 page 27:


Because of noise-level scaling with Δf, spectra for noise measurement often
are displayed in a normalized format called power or amplitude spectral
density. The power or amplitude spectral density normalizes the power or
amplitude spectrum to the spectrum measured by a 1 Hz-wide square filter,
a convention for noise-level measurements. The level at each frequency line
is equivalent to the level obtained using a 1 Hz filter centered at that
frequency line.

I recommend checking out that manual.  Please let us know if you have any other questions!

Regards,