LabVIEW

cancel
Showing results for 
Search instead for 
Did you mean: 

Noise power bandwidth window

Hello, Can someone advise me on this.
PSD= power spectrum in vrms^2 / (freq resolution x Noise power bandwidth of window) 
i have read through the Smoothing windows.
 
i tried to calculate the PSD with the values of FFT power spectrum.vi divide by my frequency resolution and tried to get the Noise power bandwidth of the window which is not a consistent value for all the spectrum? and in wat ways does ENBW related to the Noise power bandwidth window. say i am using hanning window and ENBW says is 1.5.
 
 
 
0 Kudos
Message 1 of 5
(3,631 Views)
Hi celynn,

I'm assuming by "Smoothing windows" you are referring to this document.

As far as I can tell, using the ENBW (Equivalent Noise-Power Band Width) for a particular window should work just fine as your NBW (Noise-Power Band Width)...

Where did you get that formula (PSD=...)?
What kind of results are you getting from this calculation?
Do you have any more specific problems or questions that I could help out with?

Thanks


0 Kudos
Message 2 of 5
(3,586 Views)
i cant create the correct coherence waveform based on the coherence function i get in the FRF.
can you please advise my mistakes?
Attached is my vi.
0 Kudos
Message 3 of 5
(3,579 Views)
Attached is the front panel of the vi,
0 Kudos
Message 4 of 5
(3,581 Views)

The sub vi 1 shows the average FFT Power spectrum of the data. and the sub vi 2 is creating the FFT blocks. The coherence function obtain using the FRF vi is the desired output. But why cant i achieve that when i bulid my own blocks?

Please advise.

Many Thanks.

0 Kudos
Message 5 of 5
(3,565 Views)